Module 10 -- Lobes of the Brain:

Frederick Robert Carrick, DC, PhD, DACAN, DABCN, DACAN, DAAPM, FACCN,

Distinguished Post Graduate Professor of Clinical Neurology, Logan College.

Module 10 of the Diplomate in Neurology Program emphasizes the stereotactic relationships

of the lobes of the human brain to function. The breadth of information in this knowledge

area module is specific to the anatomy and physiology of the lobes of the brain and the

specific functional relationships of specific brain areas to general and specific plastic human

expression. The depth of information in this knowledge area will be specific to clinical

applications utilizing non pharmaceutical and non surgical methodology. Clinical techniques

specific to the application of the knowledge area will be introduced.

The following references have been utilized by Prof. Carrick in his preparation of his lecture

on the Lobes of the Brain. The abstracts of these references are the reading requirements for

this module. Due to the changing state of knowledge in the field of brain there are no text

required readings or references for this module that represent the current level of knowledge

represented in these references.

 

1. Abdullaev, Y. G.; Posner, M. I. Event-related brain potential imaging of semantic

encoding during processing single words. Neuroimage. 1998 Jan; 7(1): 1-13; ISSN:

1053-8119.

UNITED-STATES. Functional brain imaging studies with positron emission

tomography (PET) have identified blood flow changes in widely separated areas

of brain during the performance of word processing tasks. In the present study we

have utilized event-related brain potentials (ERPs) to investigate the temporal

relationships among cortical areas previously identified by PET to be

differentially activated when performing semantic tasks with visual words. ERPs

revealed task-related differences over the central and left inferior frontal regions

around 170 and 220 ms, respectively, over a left occipital region around 200 ms,

over a large left parietotemporal region around 600 ms, and finally over the right

temporal lobe around 800 ms after the word presentation. Analysis of

topographic maps and dipole sources as well as PET data allowed relating frontal

midline positivity around 170 ms to the anterior cingulate activation, and left

inferior frontal positivity around 220 ms to the PET activation of the left inferior

prefrontal cortex. The left parieto-temporal positivity around 600 ms seems to

reflect the activity of Wernicke's area. The right anterior temporal negativity

beginning around 800 ms and peaking around 1100 ms may reflect the activity of

the right insula. The left occipital negativity around 200 ms is likely to reflect

activation of a visual word-form area in the left occipital lobe. These results

provide the time course for parts of the circuitry involved in semantic processing

of words and also demonstrate how combining the spatial localization of PET

with the temporal resolution of ERPs helps to understand the brain mechanisms

involved in human cognition.

2. Abounader, R.; Hamel, E. Associations between neuropeptide Y nerve terminals and

intraparenchymal microvessels in rat and human cerebral cortex. J-Comp-Neurol.

1997 Nov 24; 388(3): 444-53; ISSN: 0021-9967.

UNITED-STATES. Neuropeptide Y (NPY) can influence local brain perfusion,

possibly via direct relationships with the microvascular bed. To evaluate this

possibility, the authors quantitatively analyzed by light and electron microscopy

the morphological associations between immunostained NPY neuronal elements

and intraparenchymal microvessels in the rat and human cerebral cortex. At the

light microscopic level in the rat frontoparietal cortex, about 16% of NPY neurons

and large proximal processes as well as a subset of nerve terminals not affected by

double sympathectomy were associated with penetrating arterioles and local

microvessels. In human temporal cortex, a dense network of NPY nerve fibers was

observed, many of which approached and/or contacted intracortical vessels. At

the ultrastructural level, 14% of NPY axonal varicosities in the rat cerebral cortex

were considered perivascular and associated with capillaries (approximately 70%)

or microarterioles (approximately 30%). They were particularly enriched in the

immediate vicinity (< 0.25 micron) of the microvessels, where the perivascular

astrocytic leaflets represented a frequent target. In human cerebral cortex, NPY

varicosities were observed in proximity to microvessels corresponding primarily

to capillaries. Perivascular NPY varicosities never established synaptic junctions

with vascular or astroglial elements. The results show that central NPY nerve

terminals associate with microvessels and perivascular astroglial cells in the rat

and human cerebral cortex. Thus, NPY released from these nerves could possibly

influence (via a parasynaptic mode of action) vascular and/or astrocytic functions

depending on the distribution of NPY receptors in these cellular compartments.

These results provide morphological support for the effects of NPY on brain

perfusion and homeostasis.. 0.

3. Alden, J. D.; Harrison, D. W.; Snyder, K. A.; Everhart, D. E. Age differences in

intention to left and right hemispace using a dichotic listening paradigm.

Neuropsychiatry-Neuropsychol-Behav-Neurol. 1997 Oct; 10(4): 239-42; ISSN:

0894-878X.

UNITED-STATES. This study assessed the influence of age (younger women

and elderly women living in communities) on cerebral laterality using dichotic

listening. Previous research has purported to show a relative right cerebral decline

with age. To date, however, research on the right hemiaging hypothesis has

provided mixed findings. It is possible that these mixed findings are caused by use

of simple versus complex dichotic listening tasks. As a test of this hypothesis,

older women were expected to have a heightened right ear advantage (REA) for

phonemic speech sounds and greater difficulty switching intention to the left ear

when instructed to focus to either the left or the right ear. No age difference was

found using the traditional presentation of concurrent phonemes. However, the

right hemiaging hypothesis was supported on the intentional task, in which older

women were less able to switch intention to the left but not to the right ear.

Implications for right hemiaging are discussed.

4. Alexander, M. J.; DeSalles, A. A.; Tomiyasu, U. Multiple radiation-induced

intracranial lesions after treatment for pituitary adenoma. Case report. J-

Neurosurg. 1998 Jan; 88(1): 111-5; ISSN: 0022-3085.

UNITED-STATES. This 53-year-old man presented with a syncopal episode 31

years after undergoing craniotomy and external-beam radiation for a pituitary

macroadenoma. A gadolinium-enhanced magnetic resonance (MR) image of the

brain demonstrated a 2.5-cm enhancing mass in the right caudate region that had

not been seen on previous studies. A stereotactically guided biopsy procedure

was performed to obtain specimens from the mass, which were consistent with

ependymoma. The MR image also revealed two additional lesions that appeared

to be within the radiation fields: a right temporal meningioma and a left frontal

cavernous malformation. A review of the literature found three previous reports in

which ependymomas presented after radiation therapy.

5. Alonso, S. J.; Navarro, E.; Santana, C.; Rodriguez, M. Motor lateralization, behavioral

despair and dopaminergic brain asymmetry after prenatal stress. Pharmacol-

Biochem-Behav. 1997 Oct; 58(2): 443-8; ISSN: 0091-3057.

UNITED-STATES. This paper presents data suggesting a relationship between

rat behavioral despair in the Porsolt test and motor lateralization in the T-maze

test. In addition, experimental evidence suggests a functional coupling among

dopaminergic systems, behavioral despair and motor lateralization. In the first

experiment, female, not male, rats with a high level of behavioral despair showed a

low level of behavioral lateralization. The inverse relationship was found in female

offspring of mothers stressed during gestation. In comparison with unstressed-

mother rats, the female offspring of stressed mothers showed an increase of

dopamine (DA) and a decrease of dihydroxyphenylacetic acid (DOPAC) and

Homovanillic (HVA) levels and of DOPAC:DA and HVA:DA indexes in the n.

accumbens of the right side of the brain. No significant differences were found in

the n. accumbens of the left brain. Taken together, the present data provide

evidence of a relation between behavioral despair and motor lateralization,

suggesting that the biological dopaminergic inervation of n. accumbens could be

the basis for this functional coupling. Because the stress of gestant mothers

modified these biochemical and behavioral variables, the present study also

suggests that lateralization of behavior and emotion during adulthood can be

modified by prenatal variables.. 51-61-6.

6. Amunts, K.; Schlaug, G.; Schleicher, A.; Steinmetz, H.; Dabringhaus, A.; Roland, P.

E.; Zilles, K. Asymmetry in the human motor cortex and handedness.

Neuroimage. 1996 Dec; 4(3 Pt 1): 216-22; ISSN: 1053-8119.

UNITED-STATES. Handedness is one of the most obvious functional

asymmetries, but its relation to an anatomical asymmetry of the hand

representation area in the motor cortex has not been demonstrated. This would be

a crucial test for the hypothesis of structure-function correlation in cortical motor

organization. Using magnetic resonance morphometry, we show for the first time

that the depth of the central sulcus is related to handedness. In right-handers, the

left central sulcus is deeper than the right, and vice versa in left-handers.

Macrostructural asymmetry is complemented by a microstructural left-larger-

than-right asymmetry in neuropil volume (i.e., tissue compartment containing

dendrites, axons, and synapses) in Brodmann's area 4. These asymmetries suggest

that hand preference is associated with increased connectivity (demonstrated by

an increased neuropil compartment in left area 4) and an increased intrasulcal

surface of the precentral gyrus in the dominant hemisphere.

7. Amunts, K.; Schmidt Passos, F.; Schleicher, A.; Zilles, K. Postnatal development of

interhemispheric asymmetry in the cytoarchitecture of human area 4. Anat-

Embryol-Berl. 1997 Nov; 196(5): 393-402; ISSN: 0340-2061.

GERMANY. The postnatal development of interhemispheric asymmetry was

analyzed in the primary motor cortex (area 4) of 20 human brains with

quantitative cytoarchitectonic techniques. The volume fraction of cortical tissue

occupied by cell bodies (grey level index) was determined by automated image

analysis. In children as well as in adults, the volume fraction of cell bodies

averaged over all cortical layers was greater on the right than on the left. Thus, the

space between cell bodies, i.e. the volume fraction of neuropil containing axons,

dendrites and synapses, was greater in the left than in the right primary motor

cortex. At the level of single layers, however, interhemispheric asymmetry of the

neuropil volume fraction differed between age groups. The supragranular layers

were significantly less asymmetrical in children than in adults, whereas the

infragranular layers showed a similar degree of asymmetry in both age groups.

Thus, the postnatal development of the architectonic asymmetry in the supra-

and infragranular layers of area 4 follows the same sequence of maturation as

found during neuronal migration, i.e. an inside-to-outside gradient. Comparing the

layer-specific developmental pattern with available functional data, it was found

that the structural maturation of interhemispheric asymmetry in the supragranular

layers correlates with the development of hand preference.

8. Andersson, J. L. How to estimate global activity independent of changes in local

activity. Neuroimage. 1997 Nov; 6(4): 237-44; ISSN: 1053-8119.

UNITED-STATES. A method is suggested to ensure independence between the

estimated global flow and changes in local flow in PET activation studies. Global

flow is estimated as the average of all intracerebral voxels, except those that

exhibit a consistent change in flow as a consequence of the experimental design.

This is achieved by performing an initial analysis, using all intracerebral voxels for

estimation of global flow, in which an F-map depicting task related changes is

produced. A second analysis is performed, now excluding all voxels with a P <

0.05 in the F-map when evaluating global flow, thereby ensuring independence

from areas changing in a task-dependent manner. The feasibility of the method is

demonstrated on phantom data, showing that the distribution is skewed in

nonactivated areas when including the activated areas in the calculation of global

flow. By excluding these areas the distribution is translated toward zero and

becomes consistent with the null-hypothesis. Furthermore, the usefulness of the

suggested scheme is demonstrated on human data. Scans performed while subjects

watched a movie featuring snakes were contrasted to scans performed while

watching white noise, producing highly significant activations of the visual

system. When using the traditional way of estimating global flow, deactivations

were observed in very large portions of the frontal, parietal, and temporal lobes.

When using the method suggested in the present paper these disappeared, which

would be more consistent with the expected effects of stimulation. The method

was used in conjunction with both ratio and ANCOVA adjustment with very

similar results. Copyright 1997 Academic Press.

9. Andreasen, N. C.; O'Leary, D. S.; Cizadlo, T.; Arndt, S.; Rezai, K.; Watkins, G. L.;

Ponto, L. L.; Hichwa, R. D. II. PET studies of memory: novel versus practiced

free recall of word lists. Neuroimage. 1995 Dec; 2(4): 296-305; ISSN: 1053-8119.

UNITED-STATES. Positron emission tomography (PET) with the tracer

H215O was used to measure regional cerebral blood flow in 13 healthy volunteers

while they engaged in free recall of 15-item word lists from the Rey Auditory

Verbal Learning task. The study was designed so that recall of well-practiced

versus novel material could be compared. One week before the PET study,

subjects were trained to perfect recall of List A, while they were exposed to list B

only 60 s prior to PET data acquisition. As in the companion study of free recall

of complex narratives, we observed that practice tended to decrease the size of

activations in regions involved in the memory component of the task; we also

observed that the novel recall task produced greater activation in left frontal

regions, probably due to active encoding. A commonality of other regions

observed in this pair of studies, as well as other studies of memory in the

literature, suggests that the human brain may contain a distributed multinodal

general memory system. Nodes on this network include the frontal, parietal, and

temporal cortices, the thalamus, the anterior and posterior cingulate, the

precuneus, and the cerebellum. There appears to be a commonality of components

across tasks (e.g., retrieval, encoding) that is independent of content, as well as

differentiation of some components that may be content-specific or tasks-

specific. In addition, these results support a significant role for the cerebellum in

cognitive functions such as memory.

10. Annoni, J. M.; Pegna, A. J. Random motor generation in a finger tapping task:

influence of spatial contingency and of cortical and subcortical hemispheric brain

lesions. J-Neurol-Neurosurg-Psychiatry. 1997 Nov; 63(5): 654-9; ISSN: 0022-

3050.

ENGLAND. OBJECTIVE: To test the hypothesis that, during random motor

generation, the spatial contingencies inherent to the task would induce additional

preferences in normal subjects, shifting their performances farther from

randomness. By contrast, perceptual or executive dysfunction could alter these

task related biases in patients with brain damage. METHODS: Two groups of

patients, with right and left focal brain lesions, as well as 25 right handed subjects

matched for age and handedness were asked to execute a random choice motor

task--namely, to generate a random series of 180 button presses from a set of 10

keys placed vertically in front of them. RESULTS: In the control group, as in the

left brain lesion group, motor generation was subject to deviations from theoretical

expected randomness, similar to those when numbers are generated mentally, as

immediate repetitions (successive presses on the same key) are avoided. However,

the distribution of button presses was also contingent on the topographic

disposition of the keys: the central keys were chosen more often than those

placed at extreme positions. Small distances were favoured, particularly with the

left hand. These patterns were influenced by implicit strategies and task related

contingencies. By contrast, right brain lesion patients with frontal involvement

tended to show a more square distribution of key presses--that is, the number of

key presses tended to be more equally distributed. The strategies were also altered

by brain lesions: the number of immediate repetitions was more frequent when the

lesion involved the right frontal areas yielding a random generation nearer to

expected theoretical randomness. The frequency of adjacent key presses was

increased by right anterior and left posterior cortical as well as by right subcortical

lesions, but decreased by left subcortical lesions. CONCLUSIONS: Depending on

the side of the lesion and the degree of cortical-subcortical involvement, the

deficits take on a different aspect and direct repetions and adjacent key presses

have different patterns of alterations. Motor random generation is therefore a

complex task which seems to necessitate the participation of numerous cerebral

structures, among which those situated in the right frontal, left posterior, and

subcortical regions have a predominant role.

11. Aouda, A.; Hayashi, F.; Fukuda, Y.; Masuda, Y. An in vitro brainstem-heart

preparation of the neonatal rat with intact right vagus nerve. Jpn-J-Physiol. 1997

Oct; 47(5): 443-8; ISSN: 0021-521X.

JAPAN. An in vitro brainstem preparation of the neonatal rat with intact right

vagal (X) innervation of the right atrium, and intact medullary roots of the left X

and glossopharyngeal (IX) nerves for stimulation was developed. The preparation

was continuously superfused with artificial CSF at 25 degrees C. The electrical

activity of the right atrium was recorded to determine the heart rate. Applications

of atropine or propranolol to the superfusate did not alter the heart rate. Electrical

stimulation (0.5 ms pulse, 20 Hz) of the left IX and X afferents elicited a

reduction in the heart rate from 70.3 +/- 13.2 to 50.6 +/- 13.2 beats/min (mean +/-

SD, p < 0.05), which was abolished after division of the right X or application of

atropine to the superfusing solution. A similar reflex bradycardia was seen in a

preparation with intact left vagal-right atrium innervation during right IX and X

afferent stimulation. Cervical spinal cord transection affected neither the baseline

heart rate nor the magnitude of the reflex bradycardia. Longitudinal sectioning of

the medulla oblongata in the mid-line down to the level of the posterior inferior

cerebellar artery abolished the heart rate response. After bilateral cervical

vagotomies, electrical stimulation (0.5 ms pulse, 20 Hz, up to 100 microA) of the

ventrolateral medulla oblongata, lateral funiculus at C2 or intermediate nucleus of

the spinal cord at Th1-4 did not affect the heart rate. These results indicate that

the functions in the lower brainstem are preserved in this preparation, at least in

regard to the generation of reflex bradycardia. The results also suggest that the

laterality of cardiac vagal innervation and sympathetic innervation will develop

during the postnatal period. This preparation may be useful for the study of the

central neuronal network controlling the heart rate.. 0; 0; 51-55-8; 525-66-6.

12. Arndt, S.; Cizadlo, T.; O'Leary, D.; Gold, S.; Andreasen, N. C. Normalizing counts

and cerebral blood flow intensity in functional imaging studies of the human brain.

Neuroimage. 1996 Jun; 3(3 Pt 1): 175-84; ISSN: 1053-8119.

UNITED-STATES. Image intensity normalization is frequently applied to

eliminate or adjust for subject or injection global blood flow (gCBF) and other

sources of nuisance variation. Normalization has several other positive effects on

the analysis of PET images. However, the choice of an intensity normalization

technique affects the statistical and psychometric properties of the image data.

We compared three normalization procedures, the ratio approach (regional

(r)CBF/gCBF), histogram equalization, and ANCOVA, on both PET count and

flow data sets. The ratio method presents the proportional increase of regions, the

histogram equalization method offers the relative ranking of intensities over the

image, and the ANCOVA method provides statistical deviations from an expected

linear model of regional values from the subject's gCBF. The original study used

33 normal subjects in a standard subtraction paradigm. The normalization

methods were evaluated on their ability to remove extraneous error variation,

induce homogeneity of intersubject variation, and remove unwanted dependencies.

In general, the normalization modified the subtraction image more than the

individual condition images. All three methods worked well at removing the

dependency of rCBF on gCBF in count and flow images. For count data, the three

methods also reduced the amount of error variation equally well, improving the

signal to noise ratio. For flow data, the histogram equalization and ratio methods

worked best at reducing statistical error. All three methods dramatically stabilized

the variance over the image.

13. Arrowsmith, J. E.; Robertshaw, H. J.; Boyd, J. D. Nasotracheal intubation in the

presence of frontobasal skull fracture. Can-J-Anaesth. 1998 Jan; 45(1): 71-5;

ISSN: 0832-610X.

CANADA. PURPOSE: To present a case of maxillofacial trauma and basal skull

fracture (BSF) in whom nasotracheal intubation (NTI) was successfully used,

without complication, to facilitate surgical fixation. To present alternative

methods of airway management in this situation and to review the evidence

supporting the notion that NTI is contraindicated in the presence of basal skull

fracture. CLINICAL FEATURES: A 17-yr-old man was referred for surgical

fixation of bilateral mandibular fractures. Cranial computed tomography revealed

intracranial air and blood in all four sinuses and distortion of the nasal passage on

the right. There was no cerebral injury and the left nasal passage appeared patent.

In order to facilitate intraoperative intermaxillary fixation fibreoptic NTI was

undertaken in preference to tracheostomy. The patient made an uneventful

recovery without evidence of meningitis or direct cerebral injury. CONCLUSION:

In selected patients NTI may be performed in the presence of BSF. Available

evidence suggests that BSF-should not be regarded as an absolute contraindication

to NTI.

14. Asano, K.; Sekiya, T.; Shimamura, N.; Tanaka, M.; Takemura, A.; Suzuki, S.; Kubo,

O. [A case of giant cell-rich gliosarcoma]. No-To-Shinkei. 1997 Oct; 49(10): 938-

44; ISSN: 0006-8969.

JAPAN. We report a case of gliosarcoma with numerous giant cells resembling

ganglion cells and having clear nucleoli. A 75-year woman was admitted to our

hospital suffering from progressive left hemiparesis and ambulatory disturbance

of one week's duration. CT and MRI studies showed ring enhancement on a clear

margin mass in the right parieto-occipital lobe. The mass was totally removed

macroscopically. Her left hemiparesis had improved and self walk came to be

possible. But the tumor was regrowthed during next two months and she died for

three months and a week. The gross and microscopic appearances of the tumors

showed the double structure. The surface of the tumor was well enhanced and

consisted of soft, gray, and easily bleeding tissue. The central core, however, was

poorly enhanced and consisted of hard, yellow, non-bleeding tissue.

Macroscopically, the central area included numerous giant ganglion-like cells

which were negative for GFAP but positive for EMA in the cytoplasm. These

giant cells had abundant collagen fibers and were surrounded by such fibers.

Microscopic findings of the surrounding area included numerous spindle shaped

cells which were positive for GFAP and vimentin. The origins of giant cells or

tumor tissues have long been discussed, but no consensus has yet been obtained.

Therefore, we speculated as to the origin in our patient based on

immunohistochemical study and the findings of electronmicroscopy. We

concluded, in sharp contrast to the old theory of one origin, epithelial tissue of a

hamartomatous nature existed initially, followed by the growth of malignant tissue

of a reactive astrocytic tumor with a sarcomatous component.. 80529-93-7.

15. Badan, M.; Caramazza, A. Haptic processing by the left hemisphere in a split-brain

patient. Neuropsychologia. 1997 Sep; 35(9): 1275-87; ISSN: 0028-3932.

ENGLAND. We report the case of a patient who suffered an ischemic accident

resulting in damage to the anterior part of the corpus callosum and to the white

matter in the posterior right hemisphere. Recognition of two-dimensional haptic

stimuli explored with the right hand was severely impaired. The deficit was not

specific to the type of stimuli, since letters, digits and geometrical shapes were

not correctly recognized. Poor performance was not due to a specific mode of

haptic exploration, since deficits were also observed without active manipulation

of the stimuli. In contrast, the patient correctly named visual letters presented in

the right visual hemifield (left hemisphere), and recognized three-dimensional

common objects palpated with the right hand. Comparable results were observed

in a surgical split-brain patient tested as a control. We conclude that (i) the

construction of spatial representations of haptic stimuli, such as two-dimensional

stimuli or three-dimensional block letters, cannot be fully realized in the intact left

hemisphere, this ability requiring the contribution of both hemispheres, and (ii)

tests for correct naming of common objects do not provide sufficient evidence to

establish the integrity of the system involved in the identification of haptic

information processed by the right hand of split-brain patients.

16. Bandettini, P. A.; Wong, E. C. A hypercapnia-based normalization method for

improved spatial localization of human brain activation with fMRI. NMR-

Biomed. 1997 Jun; 10(4-5): 197-203; ISSN: 0952-3480.

ENGLAND. An issue in blood oxygenation level dependent contrast-based

functional MRI is the accurate interpretation of the activation-induced signal

changes. Hemodynamic factors other than activation-induced changes in blood

oxygenation are known to contribute to the signal change magnitudes and

dynamics, and therefore need to be accounted for or removed. In this paper, a

general method for removal of effects other than activation-induced blood

oxygenation changes from fMRI brain activation maps by the use of hypercapnic

stress normalization is introduced. First, the effects of resting blood volume

distribution across voxels on activation-induced BOLD-based fMRI signal

changes are shown to be significant. Second, the effects of hypercapnia and

hypoxia on resting and activation-induced signal changes are demonstrated. These

results suggest that global hemodynamic stresses may be useful for non-invasive

mapping of blood volume. Third, the normalization technique is demonstrated..

124-38-9; 7782-44-7.

17. Bandettini, P. A.; Wong, E. C. A hypercapnia-based normalization method for

improved spatial localization of human brain activation with fMRI. NMR-

Biomed. 1997 Jun; 10(4-5): 197-203; ISSN: 0952-3480.

ENGLAND. An issue in blood oxygenation level dependent contrast-based

functional MRI is the accurate interpretation of the activation-induced signal

changes. Hemodynamic factors other than activation-induced changes in blood

oxygenation are known to contribute to the signal change magnitudes and

dynamics, and therefore need to be accounted for or removed. In this paper, a

general method for removal of effects other than activation-induced blood

oxygenation changes from fMRI brain activation maps by the use of hypercapnic

stress normalization is introduced. First, the effects of resting blood volume

distribution across voxels on activation-induced BOLD-based fMRI signal

changes are shown to be significant. Second, the effects of hypercapnia and

hypoxia on resting and activation-induced signal changes are demonstrated. These

results suggest that global hemodynamic stresses may be useful for non-invasive

mapping of blood volume. Third, the normalization technique is demonstrated..

124-38-9; 7782-44-7.

18. Bandinelli, G.; Cencetti, S.; Buccheri, A. M.; Lagi, A. Noninvasive assessment of

posterior cerebral artery stenosis inducing hemiplegia. Ann-Ital-Med-Int. 1997

Jan; 12(1): 31-4; ISSN: 0393-9394.

ITALY. Posterior cerebral artery infarction usually causes hemianopsia and,

occasionally, symptoms referred to infarction in the territory of the middle

cerebral artery. We describe a case of cerebral infarction of the posterior cerebral

artery territory that mimicked middle cerebral artery occlusion. A patient with

infarction of the right surface and deep territories of the posterior cerebral artery

presented with left hemiplegia and left homonymous hemianopsia. Brain

computed tomography and magnetic resonance investigation disclosed a

hypodense lesion in the occipital right lobe and the medial and inferior part of the

right temporal lobe. Transcranial Doppler studies disclosed an abnormally

increased blood flow velocity in the proximal posterior cerebral artery and a sharp

reduction in distal flow velocity. This case underscores the utility of noninvasive

techniques to diagnose posterior artery stenosis: they were not only more

economical than angiography but also spared the patient discomfort and risk.

19. Barbas, H.; Rempel Clower, N. Cortical structure predicts the pattern of

corticocortical connections. Cereb-Cortex. 1997 Oct; 7(7): 635-46; ISSN: 1047-

3211.

UNITED-STATES. Cortical areas are linked through pathways which originate

and terminate in specific layers. The factors underlying which layers are involved

in specific connections are not well understood. Here we tested whether cortical

structure can predict the pattern as well as the relative distribution of projection

neurons and axonal terminals in cortical layers, studied with retrograde and

anterograde tracers. We used the prefrontal cortices in the rhesus monkey as a

model system because their laminar organization varies systematically, ranging

from areas that have only three identifiable layers, to those that have six layers.

We rated each prefrontal area based on the number and definition of its cortical

layers (level 1, lowest; level 5, highest). The structural model accurately predicted

the laminar pattern of connections in approximately 80% of the cases. Thus,

projection neurons from a higher-level cortex originated mostly in the upper layers

and their axons terminated predominantly in the deep layers (4-6) of a lower-level

cortex. Conversely, most projection neurons from a lower-level area originated in

the deep layers and their axons terminated predominantly in the upper layers (1-

3) of a higher-level area. In addition, the structural model accurately predicted that

the proportion of projection neurons or axonal terminals in the upper to the deep

layers would vary as a function of the number of levels between the connected

cortices. The power of this structural model lies in its potential to predict

patterns of connections in the human cortex, where invasive procedures are

precluded.. 0.

20. Baumgartner, R.; Scarth, G.; Teichtmeister, C.; Somorjai, R.; Moser, E. Fuzzy

clustering of gradient-echo functional MRI in the human visual cortex. Part I:

reproducibility. J-Magn-Reson-Imaging. 1997 Nov; 7(6): 1094-101; ISSN: 1053-

1807.

UNITED-STATES. Reproducibility of human functional MRI (fMRI) studies is

essential for clinical and neuroresearch applications of this new human brain

mapping method. Based on a recently presented study on reproducibility of

gradient-echo fMRI in the human visual cortex (Moser et al. Magn Reson Imaging

1996; 14:567-579), comparing the performance of three different threshold

strategies for correlation analysis, we demonstrate that (a) fuzzy clustering is a

robust, model-independent method to extract functional information in time and

space; (b) intertrial reproducibility of cortical activation is significantly improved

by the capability of fuzzy clustering to separate signal contributions from larger

vessels, running perpendicular to the slice orientation, from activation apparently

close to the primary visual cortex; and (c) for repeated single subject studies, SDs

of <20% for signal enhancement in approximately 80% of the studies and SDs of

<30% for activated area size in approximately 65% of the studies are obtained.

This, however, depends also on signal-to-noise ratio, (motion) artifacts, and

subject cooperation.

21. Bechara, A.; Damasio, H.; Tranel, D.; Anderson, S. W. Dissociation Of working

memory from decision making within the human prefrontal cortex. J-Neurosci.

1998 Jan 1; 18(1): 428-37; ISSN: 0270-6474.

UNITED-STATES. We tested the hypothesis that cognitive functions related to

working memory (assessed with delay tasks) are distinct from those related to

decision making (assessed with a gambling task), and that working memory and

decision making depend in part on separate anatomical substrates. Normal

controls (n = 21), subjects with lesions in the ventromedial (VM) (n = 9) or

dorsolateral/high mesial (DL/M) prefrontal cortices (n = 10), performed on (1)

modified delay tasks that assess working memory and (2) a gambling task

designed to measure decision making. VM subjects with more anterior lesions (n =

4) performed defectively on the gambling but not the delay task. VM subjects

with more posterior lesions (n = 5) were impaired on both tasks. Right DL/M

subjects were impaired on the delay task but not the gambling task. Left DL/M

subjects were not impaired on either task. The findings reveal a cognitive and

anatomic double dissociation between deficits in decision making (anterior VM)

and working memory (right DL/M). This presents the first direct evidence of such

effects in humans using the lesion method and underscores the special importance

of the VM prefrontal region in decision making, independent of a direct role in

working memory.

22. Bernardi, L.; Hayoz, D.; Wenzel, R.; Passino, C.; Calciati, A.; Weber, R.; Noll, G.

Synchronous and baroceptor-sensitive oscillations in skin microcirculation:

evidence for central autonomic control. Am-J-Physiol. 1997 Oct; 273(4 Pt 2):

H1867-78; ISSN: 0002-9513.

UNITED-STATES. To determine whether skin blood flow is local or takes part

in general regulatory mechanisms, we recorded laser-Doppler flowmetry (LDF;

left and right index fingers), blood pressure, muscle sympathetic nerve activity

(MSNA), R-R interval, and respiration in 10 healthy volunteers and 3 subjects

after sympathectomy. We evaluated 1) the synchronism of LDF fluctuations in

two index fingers, 2) the relationship with autonomically mediated fluctuations in

other signals, and 3) the LDF ability to respond to arterial baroreflex stimulation

(by neck suction at frequencies from 0.02 to 0.20 Hz), using spectral analysis

(autoregressive uni- and bivariate, time-variant algorithms). Synchronous LDF

fluctuations were observed in the index fingers of healthy subjects but not in

sympathectomized patients. LDF fluctuations were coherent with those obtained

for blood pressure, MSNA, and R-R interval. LDF fluctuations were leading

blood pressure in the low-frequency (LF; 0.1 Hz) band and lagging in the

respiratory, high-frequency (HF; approximately 0.25 Hz) band, suggesting

passive "downstream" transmission only for HF and "upstream" transmission for

LF from the microvessels. LDF fluctuations were responsive to sinusoidal neck

suction up to 0.1 Hz, indicating response to sympathetic modulation. Skin blood

flow thus reflects modifications determined by autonomic activity, detectable by

frequency analysis of spontaneous fluctuations.

23. Berthoz, A. Parietal and hippocampal contribution to topokinetic and topographic

memory. Philos-Trans-R-Soc-Lond-B-Biol-Sci. 1997 Oct 29; 352(1360): 1437-48;

ISSN: 0962-8436.

ENGLAND. This paper reviews the involvement of the parietal cortex and the

hippocampus in three kinds of spatial memory tasks which all require a memory

of a previously experienced movement in space. The first task compared, by

means of positron emission tomography (PET) scan techniques, the production,

in darkness, of self-paced saccades (SAC) with the reproduction, in darkness, of a

previously learned sequence of saccades to visual targets (SEQ). The results show

that a bilateral increase of activity was seen in the depth of the intraparietal sulcus

and the medial superior parietal cortex (superior parietal gyrus and precuneus)

together with the frontal sulcus but only in the SEQ task, which involved memory

of the previously seen targets and possibly also motor memory. The second task

is the vestibular memory contingent task, which requires that the subject makes,

in darkness, a saccade to the remembered position of a visual target after a

passively imposed whole-body rotation. Deficits in this task, which involves

vestibular memory, were found predominantly in patients with focal vascular

lesions in the parieto-insular (vestibular) cortex, the supplementary motor area-

supplementary eye field area, and the prefrontal cortex. The third task requires

mental navigation from the memory of a previously learned route in a real

environment (the city of Orsay in France). A PET scan study has revealed that

when subjects were asked to remember visual landmarks there was a bilateral

activation of the middle hippocampal regions, left inferior temporal gyrus, left

hippocampal regions, precentral gyrus and posterior cingulate gyrus. If the

subjects were asked to remember the route, and their movements along this route,

bilateral activation of the dorsolateral cortex, posterior hippocampal areas,

posterior cingulate gyrus, supplementary motor areas, right middle hippocampal

areas, left precuneus, middle occipital gyrus, fusiform gyrus and lateral premotor

area was found. Subtraction between the two conditions reduced the activated

areas to the left hippocampus, precuneus and insula. These data suggest that the

hippocampus and parietal cortex are both involved in the dynamic aspects of

spatial memory, for which the name 'topokinetic memory' is proposed. These

dynamic aspects could both overlap and be different from those involved in the

cartographic and static aspects of 'topographic' memory.

24. Bevan, R. D.; Vijayakumaran, E.; Gentry, A.; Wellman, T.; Bevan, J. A. Intrinsic tone

of cerebral artery segments of human infants between 23 weeks of gestation and

term. Pediatr-Res. 1998 Jan; 43(1): 20-7; ISSN: 0031-3998.

UNITED-STATES. Segments of basilar and middle cerebral arteries of eight

human preterm and early postnatal infants have been examined using the

resistance artery myograph technique for wire-mounted segments and the

pressure perfusion arteriograph. Myograph-mounted segments spontaneously

developed tone of varying duration and time course. Perfused segments showed

maintained tone levels of approximately 40% of maximum possible constriction

when the intraluminal pressure was 60 mm Hg. This level is not different from

that found in adult human pial arteries of similar lumen diameter. Indomethacin

(10[-5] M) either initiated tone increase or potentiated existing tone in the

isometrically mounted segments. After washout of vasoconstrictors

norepinephrine (10[-6] M) and angiotensin II (10[-8] M), indomethacin caused a

pronounced, long lasting increase in basal tone. Spontaneous tone was reversed by

acetylcholine (10[-6] M), isoproterenol (10[-8] to 10[-5] M), histamine (10[-8] to

10[-5] M), and papaverine (10[-5] M). Low levels of tone were increased and

higher levels decreased by intraluminal flow. The pressure/diameter curves of

these vessels were of similar shape as those of the equivalent size in the adult. It

is concluded that intrinsic tone is a prominent feature of these large cerebral

arteries, and it is modified by an endogenous indomethacin-sensitive process.

25. Bishop, K. M.; Wahlsten, D. Sex differences in the human corpus callosum: myth or

reality? Neurosci-Biobehav-Rev. 1997 Sep; 21(5): 581-601; ISSN: 0149-7634.

UNITED-STATES. It has been claimed that the human corpus callosum shows

sex differences, and in particular that the splenium (the posterior portion) is larger

in women than in men. Data collected before 1910 from cadavers indicate that, on

average, males have larger brains than females and that the average size of their

corpus callosum is larger. A meta-analysis of 49 studies published since 1980

reveals no significant sex difference in the size or shape of the splenium of the

corpus callosum, whether or not an appropriate adjustment is made for brain size

using analysis of covariance or linear regression. It is argued that a simple ratio of

corpus callosum size to whole brain size is not an appropriate way to analyse the

data and can create a false impression of a sex difference in the corpus callosum.

The recent studies, most of which used magnetic resonance imaging (MRI),

confirm the earlier findings of larger average brain size and overall corpus callosum

size for males. The widespread belief that women have a larger splenium than men

and consequently think differently is untenable. Causes of and means to avoid

such a false impression in future research are discussed.

26. Biswal, B. B.; Van Kylen, J.; Hyde, J. S. Simultaneous assessment of flow and BOLD

signals in resting-state functional connectivity maps [see comments]. NMR-

Biomed. 1997 Jun; 10(4-5): 165-70; ISSN: 0952-3480.

Note: Comment in: NMR Biomed 1997 Jun-Aug;10(4-5):157-9.

ENGLAND. We have recently demonstrated using functional magnetic resonance

imaging the presence of synchronous low-frequency fluctuations of signal

intensities from the resting human brain that have a high degree of temporal

correlation (p < 0.0001) both within and across the sensorimotor cortex. A

statistically significant overlap between the resting-state functional connectivity

map and the task-activation map due to bilateral finger tapping was obtained.

Similar results have been obtained in the auditory and visual cortex. Because the

pulse sequence used for collecting data was sensitive to blood flow and blood

oxygenation, these low-frequency fluctuations of signal intensity may have arisen

from variations of both. The objective of this study was simultaneously to

determine the contribution of the blood oxygenation level signal and the flow

signal to physiological fluctuations in the resting brain using the flow-sensitive

alternating inversion recovery pulse sequence. In all subjects, the functional

connectivity maps obtained from BOLD had a greater coincidence with task-

activation maps than the corresponding functional connectivity maps obtained

from blood-flow signals at the same level of statistical significance. Results of this

study suggest that while variations in blood flow might contribute to functional

connectivity maps, BOLD signals play a dominant role in the mechanism that

gives rise to functional connectivity in the resting human brain.. 7782-44-7.

27. Biver, F.; Wikler, D.; Lotstra, F.; Damhaut, P.; Goldman, S.; Mendlewicz, J.

Serotonin 5-HT2 receptor imaging in major depression: focal changes in orbito-

insular cortex. Br-J-Psychiatry. 1997 Nov; 171: 444-8; ISSN: 0007-1250.

ENGLAND. BACKGROUND: Serotonin receptors may play an important role

in the pathophysiology of affective disorders. We studied type-2 serotonin (5-

HT2) receptors in the brain of patients with major depression. METHOD: Using

positron emission tomography (PET) and the selective radioligand

[18F]altanserin, we investigated 5-HT2 receptor distribution in eight drug-free

unipolar depressed patients and 22 healthy subjects. Data were analysed using

Statistical Parametric Mapping 95. RESULTS: In depressed patients,

[18F]altanserin uptake was significantly reduced in a region of the right

hemisphere including the posterolateral orbitofrontal cortex and the anterior

insular cortex. A trend to similar changes was found in the left hemisphere. No

correlation was found between the uptake and the Hamilton rating scale score.

CONCLUSIONS: Pathophysiology of depression may involve changes in 5-HT2

receptor in brain regions selectively implicated in mood regulation.. 0; 0; 74050-

98-9; 76330-71-7.

28. Blin, J.; Ivanoiu, A.; Coppens, A.; De Volder, A.; Labar, D.; Michel, C.; Laterre, E. C.

Cholinergic neurotransmission has different effects on cerebral glucose

consumption and blood flow in young normals, aged normals, and Alzheimer's

disease patients. Neuroimage. 1997 Nov; 6(4): 335-43; ISSN: 1053-8119.

UNITED-STATES. Cerebral blood flow (CBF) and glucose consumption (GC)

are both tracers of brain metabolic activity used to image the human brain in vivo.

To know if both tracers reacted in the same manner when brain cholinergic

neurotransmission was activated, CBF and GC were measured in young normals

(YN), aged normals (AN), and Alzheimer's Disease patients (AD) using positron

emission tomography (PET), H2 15O, and 18F-FDG. Each subject was studied

twice, under placebo and physostigmine, in randomized order and blind fashion

using the maximal tolerated dose of physostigmine individually determined. Under

physostigmine CBF increased significantly (P = 0.0007) in posterior regions of

the cerebral cortex and in the subcortical structures. Inversely, GC was decreased

significantly in most regions. The largest decrease was seen in the prefrontal

region of the cerebral cortex (P < 0.0001). Significant regional decreases were

registered in all three groups of subjects, but were larger in AD than in controls.

Looking at the absolute values of prefrontal cortex metabolism we found no

correlation (r = 0.04) between the responses of CBF and GC. After normalization

of the regional values for the mean we found a significant positive correlation

between the responses of CBF and GC (r = 0.71, P < 0.0001). These findings

suggest two components in the CBF response to physostigmine: one metabolic,

depressive, and regional which follows the GC response; and one vascular, larger,

diffuse, and opposite in direction to the metabolic component. These results have

implications for the interpretation of CBF values as tracer of brain metabolic

activity when brain cholinergic neurotransmission is manipulated. Copyright 1997

Academic Press.. 0; 63503-12-8.

29. Bohning, D. E.; Pecheny, A. P.; Epstein, C. M.; Speer, A. M.; Vincent, D. J.;

Dannels, W.; George, M. S. Mapping transcranial magnetic stimulation (TMS)

fields in vivo with MRI. Neuroreport. 1997 Jul 28; 8(11): 2535-8; ISSN: 0959-

4965.

ENGLAND. Transcranial magnetic stimulation (TMS) is a non-invasive

technique for investigating brain function that uses pulsed magnetic fields created

by special coils to induce localized neuronal depolarization. Despite the

technique's expanding application, the exact magnetic field produced by TMS

coils have never been directly measured in human subjects. Using a standard 1.5T

MR scanner and TMS coils constructed from non magnetic materials, we have

obtained 3D maps of the magnetic field created by TMS coils in human

volunteers. Further, we mapped the combined field of two coils and demonstrated

that combinations of coils might be used to focus the magnetic field to achieve

improved stimulation patterns and, perhaps, reach areas out of reach of single

coils.

30. Bol, P.; Scheirs, J.; Spanjaard, L. Meningitis and the evolution of dominance of

righthandedness. Cortex. 1997 Dec; 33(4): 723-32; ISSN: 0010-9452.

ITALY. In bacterial meningitis, forced deviation of the head and/or the eyes

towards either the left or the right side reflects an ipsilateral focal inflammation of

the brain. Also, the symptom of forced deviation is associated with a high fatality

and sequelae rate. In this study it was observed that, among 2124 Dutch patients

with bacterial meningitis, forced deviation was significantly more often to the right

than to the left. Because the right hemisphere is dominant for motor functions in

natural lefthanders, it was concluded that bacterial meningitis might have been a

selection mechanism favouring the evolution of a dominance of righthandedness.

31. Bona, E.; Johansson, B. B.; Hagberg, H. Sensorimotor function and neuropathology

five to six weeks after hypoxia-ischemia in seven-day-old rats. Pediatr-Res. 1997

Nov; 42(5): 678-83; ISSN: 0031-3998.

UNITED-STATES. Various therapeutic interventions after hypoxia-ischemia

(HI) have been shown to reduce brain injury in the short-term perspective, but it

remains uncertain whether such findings are accompanied by long-term functional

and structural improvements. HI was induced in 7-d-old rats as follows. The left

carotid artery was ligated, and the rat was exposed to 100 min of hypoxia (7.70%

oxygen in nitrogen). At postnatal d 42 the rats were assessed using four

sensorimotor tests. The results were correlated with the extent of brain damage

expressed as volume of deficit of the left hemisphere as percent of the right

hemisphere. In the grip-traction test, the time to falling was 2.2 times shorter in

the HI animals compared with controls (p < 0.01). Asymmetries of limb-placing

and foot-faults (p < 0.001) were detected in HI animals, and the motor function

was abnormal in the postural reflex test (p < 0.001). We found a moderate

correspondence between functional and neuropathologic outcome (r = 0.842, p <

0.001). A set of four easily performed sensorimotor tests is presented for the

long-term evaluation of neurologic function in the 7-d-old rat model of HI.

32. Bookheimer, S. Y. Functional MRI applications in clinical epilepsy. Neuroimage.

1996 Dec; 4(3 Pt 3): S139-46; ISSN: 1053-8119.

UNITED-STATES. Functional MRI holds great promise as a diagnostic tool in

presurgical evaluation of patients with epilepsy. Recent research has used fMRI

for localization of the seizure focus by tracking interictal spikes and by observing

blood flow changes during seizure onset. Localization of the language-dominant

hemisphere with fMRI has been well-validated in normal volunteers and left-

hemisphere-dominant epilepsy patients, but is less developed for patients with

mixed- or right-hemisphere language dominance. Intrahemispheric mapping of

sensory and motor functions with fMRI is fairly well established, and progress is

being made in mapping higher-level cognitive functions, particularly language.

Little research has convincingly demonstrated hippocampal function in the normal

brain during memory processing, and applications of memory mapping in

epilepsy are still lacking. While the clinical use of fMRI in epilepsy needs

substantially more study, this is nonetheless a very promising technique that may

dramatically change the presurgical diagnostic regimen for these patients.

33. Borch, K.; Greisen, G. Blood flow distribution in the normal human preterm brain.

Pediatr-Res. 1998 Jan; 43(1): 28-33; ISSN: 0031-3998.

UNITED-STATES. Disturbances in cerebral blood flow (CBF) are a major factor

in the etiology and pathogenesis of cerebral damage in the neonate. As most

animals are more mature at birth than man, extrapolation from animal studies to

the human is questionable. Therefore, we have measured regional CBF (rCBF) in

preterm infants. rCBF flow was measured in 12 normotensive and normoxic

preterm infants [mean birth weight 915 g (range 550 to 2680 g), mean gestational

age 27.7 wk (25 to 32 wk)]. All infants had a normal cerebral ultrasound

examination. rCBF was measured using a mobile brain dedicated fast-rotating four-

head multidetector system specially designed for neonatal studies. The tracer was

99mTc-labeled D,L-hexamethylpropylenamine oxime in a dose of 4 Mbq/kg.

rCBF of the subcortical white matter was 0.53 (0.48-0.58) of the global CBF.

After correction for scattered radiation, the estimate of rCBF to the white matter

was reduced to 0.39 (0.36-0.42). The flow to the basal ganglia was 2.33 (2.08-

2.59) times the global CBF. After correction for partial volume effect, the cortical

flow was higher than the flow to the basal ganglia and highest in the

frontotemporal cortex (motor cortex). The flow to the cerebellum was of the same

magnitude as the flow to the basal ganglia, but with a significantly higher variation.

rCBF in 12 preterm infants showed a flow distribution similar to flow in other

newborn mammals. The gray-white matter contrast, however, was greater. This

new information, combined with existing data showing low global CBF, suggests

that blood flow to the white matter in the preterm human neonate is extremely

low.

34. Bowden, D. M.; Martin, R. F. NeuroNames Brain Hierarchy. Neuroimage. 1995 Mar;

2(1): 63-83; ISSN: 1053-8119.

UNITED-STATES. The NeuroNames Brain Hierarchy is a structured system of

neuroanatomical terminology that provides a comprehensive representation of

virtually all human and nonhuman primate brain structures that are identifiable

either grossly or in Niss1-stained histological sections. This system was devised

for computer applications to address deficiencies in the brain terminology

presented in Nomina Anatomica. English terms are listed for 783 structures in

nine levels of hierarchical ranking. Abbreviations are provided for all superficial

and primary volumetric structures. The substructures that constitute the total

volume of every superstructure are identified. Superficial features of the brain are

clearly distinguished from internal, volumetric brain structures. Structures found

solely in either humans or macaques are identified. The purpose of the

NeuroNames Brain Hierarchy is to bring greater standardization to the

neuroanatomical terminology used by scientific investigators, clinicians, and

students. This effort is consistent with the goals of the Unified Medical Language

System program of the National Library of Medicine. It is hoped that the

systematic construction of the NeuroNames Brain Hierarchy will facilitate use of

the most widely accepted definitions of classical neuroanatomy in quantitative

computerized neuroimaging applications. It should provide an accurate structural

framework against which to reference the many other kinds of neuroanatomical

information that are acquired by modern imaging, mapping, and histological

labeling techniques.

35. Bowler, J. V.; Wade, J. P.; Jones, B. E.; Nijran, K. S.; Steiner, T. J. Natural history of

the spontaneous reperfusion of human cerebral infarcts as assessed by 99mTc

HMPAO SPECT. J-Neurol-Neurosurg-Psychiatry. 1998 Jan; 64(1): 90-7; ISSN:

0022-3050.

ENGLAND. OBJECTIVE: Little is known about the effect of spontaneous

reperfusion of human cerebral infarcts. Single photon emission computerised

tomography (SPECT) data were analysed from a study using 99Tc(m) HMPAO

(99Tc(m) hexamethylpropyleneamine oxime) in human cerebral infarction for the

frequency of reperfusion and to see if it affected infarct size, oedema,

haemorrhagic transformation, or functional outcome. METHODS: Fifty

sequential cases of ischaemic stroke were studied with 124 99Tc(m) HMPAO

SPECT at around one day, one week, and three months after stroke along with

detailed clinical and functional assessments. RESULTS: Visually apparent

reperfusion occurred in 14 of 50 patients (28%) with a mean delay of 5.8 days

and reperfusion was seen in seven others in whom it was identified on the basis of

changes in perfusion deficit volume. It occurred in 13 of 23 embolic events but

only in three of 23 other events. In only two cases did spontaneous reperfusion

occur early enough to preserve tissue or function. Reperfusion did not otherwise

reduce infarct size, or improve clinical or functional outcome, and was not

associated with oedema but an association with haemorrhagic transformation was

suggested. Reperfusion significantly decreased the apparent perfusion defect as

measured by SPECT one week from the ictus, but was mostly non-nutritional and

transient. The mean volume of tissue preserved by nutritional reperfusion was 10

cm3, but this was unequally distributed between cases. Late washout of 99Tc(m)

HMPAO from areas of hyperaemic reperfusion may be a good prognostic marker

but is a rare phenomenon and too insensitive to be of general applicability.

CONCLUSIONS: Spontaneous reperfusion after cerebral infarction occurs in 42%

of cases within the first week but is associated with clinical improvement in only

2%. It has few adverse consequences although it may be associated with

haemorrhagic transformation.. 0; 0.

36. Braga, J.; Boesch, C. Further data about venous channels in South African Plio-

Pleistocene hominids. J-Hum-Evol. 1997 Oct; 33(4): 423-47; ISSN: 0047-2484.

ENGLAND. Original data about venous channels in South African Plio-

Pleistocene hominids are discussed. To assess possible changes in blood volume

flow of fossil hominids, we test whether dimensions of three extracranial venous

foramina were different between Australopithecus africanus and Australopithecus

(Paranthropus) robustus. Moreover, providing further data about the small

sample of South African Plio-Pleistocene hominids, we also attempt to re-analyse

the incidence of divided hypoglossal canals and four emissary foramina in a very

large sample of extant African apes representing all ages, species and subspecies,

in A. africanus and in "robust australopithecines". Up to now, only very poor

data on extracranial dimensions of venous foramina were available for fossil

hominids. However, this topic provides interesting information about the

modifications of volume flow during human evolution. Assuming that in fossil

hominids, as in humans, dimensions of condylar and mastoid foramina, as well as

those of jugular foramina, depended on volume flow through them, we conclude,

first, that volume flow through internal jugular veins was comparable in South

African australopithecines, extant chimpanzees and humans, and second, that, in

comparison with the extant less-encephalized chimpanzees (presumably reflecting

the ancestral condition), volume flow was higher through condylar veins in A. (P.)

robustus. This increase was responsible for a significantly greater amount of blood

drainage from the brain (and consequently an increased arterial blood supply). We

support the view that encephalization was the prevailing functional explanation

for volume flow increase through condylar veins in A. (P.) robustus, in

comparison with its ancestor with its presumably more ape-like degree of

encephalization. Considering the incidence of emissary canals and foramina,

significant differences between A. africanus, "robust australopithecines" and all

the extant African ape species, were tested statistically. Concerning the condylar

canal, we did not find differences between "robust australopithecines" and extant

African apes. Concerning the incidence of divided hypoglossal canals, mastoid

canals, parietal and occipital foramina, no difference was found between extant

African apes, A. africanus and "robust australopithecines". High frequencies of

either condylar or mastoid canals cannot be regarded as a "pongid condition".

Moreover, we did not find convincing data to support the hypothesis that

mastoid emissary veins (partly representing a putative "radiator" for cooling the

brain) were selected in A. africanus, in comparison with "robust

australopithecines".

37. Braun, A. R.; Balkin, T. J.; Wesensten, N. J.; Gwadry, F.; Carson, R. E.; Varga, M.;

Baldwin, P.; Belenky, G.; Herscovitch, P. Dissociated pattern of activity in visual

cortices and their projections during human rapid eye movement sleep. Science.

1998 Jan 2; 279(5347): 91-5; ISSN: 0036-8075.

UNITED-STATES. Positron emission tomography was used to measure cerebral

activity and to evaluate regional interrelationships within visual cortices and their

projections during rapid eye movement (REM) sleep in human subjects. REM

sleep was associated with selective activation of extrastriate visual cortices,

particularly within the ventral processing stream, and an unexpected attenuation

of activity in the primary visual cortex; increases in regional cerebral blood flow in

extrastriate areas were significantly correlated with decreases in the striate cortex.

Extrastriate activity was also associated with concomitant activation of limbic and

paralimbic regions, but with a marked reduction of activity in frontal association

areas including lateral orbital and dorsolateral prefrontal cortices. This pattern

suggests a model for brain mechanisms subserving REM sleep where visual

association cortices and their paralimbic projections may operate as a closed

system dissociated from the regions at either end of the visual hierarchy that

mediate interactions with the external world.

38. Breier, J. I.; Plenger, P. M.; Castillo, R.; Fuchs, K.; Wheless, J. W.; Thomas, A. B.;

Brookshire, B. L.; Willmore, L. J.; Papanicolaou, A. Effects of temporal lobe

epilepsy on spatial and figural aspects of memory for a complex geometric figure.

J-Int-Neuropsychol-Soc. 1996 Nov; 2(6): 535-40; ISSN: 1355-6177.

ENGLAND. The preoperative delayed memory performance on the Rey-

Osterrieth Complex Figure (Lezak, 1983) of 54 patients with complex partial

seizures of temporal lobe origin was analyzed using 3 different indices. One index

(composite) was derived using a common scoring method that included both

spatial and figural aspects of memory in its score. The other two indices were

derived emphasizing either spatial or figural aspects of memory for the elements

of the figure separately. All 3 indices distinguished between individuals with right-

sided (RTLE) and left-sided (LTLE) seizure onset. However, spatial memory was

significantly lower than figural memory in individuals with RTLE as compared to

those with LTLE. Both the spatial and figural memory indices were significantly

lower in the presence of magnetic resonance imaging (MRI) evidence for

hippocampal sclerosis in individuals with RTLE. Results suggest that while both

the spatial and figural aspects of nonverbal memory are sensitive to right

hippocampal dysfunction, figural memory may be less vulnerable to the effects of

RTLE.

39. Brinkley, J. F.; Bradley, S. W.; Sundsten, J. W.; Rosse, C. The digital anatomist

information system and its use in the generation and delivery of Web-based

anatomy atlases. Comput-Biomed-Res. 1997 Dec; 30(6): 472-503; ISSN: 0010-

4809.

UNITED-STATES. Advances in network and imaging technology, coupled with

the availability of 3-D datasets such as the Visible Human, provide a unique

opportunity for developing information systems in anatomy that can deliver

relevant knowledge directly to the clinician, researcher or educator. A software

framework is described for developing such a system within a distributed

architecture that includes spatial and symbolic anatomy information resources,

Web and custom servers, and authoring and end-user client programs. The

authoring tools have been used to create 3-D atlases of the brain, knee and thorax

that are used both locally and throughout the world. For the one and a half year

period from June 1995-January 1997, the on-line atlases were accessed by over

33,000 sites from 94 countries, with an average of over 4000 "hits" per day, and

25,000 hits per day during peak exam periods. The atlases have been linked to by

over 500 sites, and have received at least six unsolicited awards by outside rating

institutions. The flexibility of the software framework has allowed the

information system to evolve with advances in technology and representation

methods. Possible new features include knowledge-based image retrieval and

tutoring, dynamic generation of 3-D scenes, and eventually, real-time virtual

reality navigation through the body. Such features, when coupled with other on-

line biomedical information resources, should lead to interesting new ways for

managing and accessing structural information in medicine. Copyright 1997

Academic Press.

40. Buchner, H.; Gobbele, R.; Wagner, M.; Fuchs, M.; Waberski, T. D.; Beckmann, R.

Fast visual evoked potential input into human area V5. Neuroreport. 1997 Jul 28;

8(11): 2419-22; ISSN: 0959-4965.

ENGLAND. Studies of the human visual cortex have demonstrated that an area

for motion processing (V5) is located in the lateral occipito-temporal cortex. To

study the timing of arrival of signals in V5 we recorded multi-channel visual

evoked potentials (VEPs) to checkerboard stimuli. We then applied dipole source

analysis which was computed on a grand average of 10 subjects, and on five

individual subjects, respectively. We demonstrate an early VEP component with

onset before 30 ms and with a peak around 45 ms, located in the vicinity of V5.

This early component was independent of a second activity, which started around

50 ms and peaked around 70 ms, and was located within the striate cortex (V1).

These results provide further evidence for a very fast input to V5 before

activation of V1.

41. Buchsbaum, M. S.; Trestman, R. L.; Hazlett, E.; Siegel, BV Jr; Schaefer, C. H.; Luu

Hsia, C.; Tang, C.; Herrera, S.; Solimando, A. C.; Losonczy, M.; Serby, M.;

Silverman, J.; Siever, L. J. Regional cerebral blood flow during the Wisconsin Card

Sort Test in schizotypal personality disorder. Schizophr-Res. 1997 Oct 17; 27(1):

21-8; ISSN: 0920-9964.

NETHERLANDS. Regional cerebral blood flow (rCBF) was measured by single

photon emission computed tomography in 10 patients with schizotypal

personality disorder (SPD) and nine age- and sex-matched normal volunteers.

Subjects performed both the Wisconsin Card Sort Test (WCST) and a control

task, the Symbol Matching Test (SMT). Four-way analyses of variance were

performed to assess relative rCBF of the prefrontal cortex and of the medial

temporal region. Normal volunteers showed more marked activation in the

precentral gyrus, while SPD patients showed greater activation in the middle

frontal gyrus. Relative flow in the left prefrontal cortex was correlated with better

WCST performance in normal volunteers. SPD patients, however, showed no

such correlations in the left prefrontal cortex, but demonstrated correlations of

good and bad performance with CBF in the right middle and inferior frontal gyrus,

respectively. Thus, at least some SPD patients demonstrate abnormal patterns of

prefrontal activation, perhaps as a compensation for dysfunction in other regions.

42. Buchsbaum, M. S.; Yang, S.; Hazlett, E.; Siegel, BV Jr; Germans, M.; Haznedar, M.;

O'Flaithbheartaigh, S.; Wei, T.; Silverman, J.; Siever, L. J. Ventricular volume and

asymmetry in schizotypal personality disorder and schizophrenia assessed with

magnetic resonance imaging. Schizophr-Res. 1997 Oct 17; 27(1): 45-53; ISSN:

0920-9964.

NETHERLANDS. Magnetic resonance imaging (MRI) was performed in 12

patients with schizotypal personality disorder (SPD), 11 patients with chronic

schizophrenia, and 23 age- and sex-matched normal volunteers. MRI slices were

acquired in the axial plane at 1.2-mm intervals, and the ventricles were traced on

every other slice. The lateral ventricular system was divided into the anterior

horn, temporal horn, and dorsal lateral ventricle. Schizophrenic patients had larger

left anterior and temporal horns than the normal volunteers. Size of the left

anterior and temporal horn in SPD patients was intermediate between those of

normal volunteers and schizophrenic patients and differed significantly from

schizophrenic patients. The left-minus-right difference was larger in schizophrenic

patients than in normal volunteers or SPD patients. Thus, in their structural brain

characteristics, as well as in their clinical symptomatology, SPD patients

evidence, in attenuated form, abnormalities resembling those found in full-fledged

schizophrenia. The findings suggest that decreased left hemispheric volume, in

frontal and temporal regions, may characterize both psychotic and non-psychotic

disorders of the schizophrenia spectrum.

43. Buckner, R. L.; Koutstaal, W. Functional neuroimaging studies of encoding, priming,

and explicit memory retrieval. Proc-Natl-Acad-Sci-U-S-A. 1998 Feb 3; 95(3):

891-8; ISSN: 0027-8424.

UNITED-STATES. Human functional neuroimaging techniques provide a

powerful means of linking neural level descriptions of brain function and

cognition. The exploration of the functional anatomy underlying human memory

comprises a prime example. Three highly reliable findings linking memory-related

cognitive processes to brain activity are discussed. First, priming is accompanied

by reductions in the amount of neural activation relative to naive or unprimed task

performance. These reductions can be shown to be both anatomically and

functionally specific and are found for both perceptual and conceptual task

components. Second, verbal encoding, allowing subsequent conscious retrieval, is

associated with activation of higher order brain regions including areas within the

left inferior and dorsal prefrontal cortex. These areas also are activated by working

memory and effortful word generation tasks, suggesting that these tasks, often

discussed as separable, might rely on interdependent processes. Finally, explicit

(intentional) retrieval shares much of the same functional anatomy as the encoding

and word generation tasks but is associated with the recruitment of additional

brain areas, including the anterior prefrontal cortex (right > left). These findings

illustrate how neuroimaging techniques can be used to study memory processes

and can both complement and extend data derived through other means. More

recently developed methods, such as event-related functional MRI, will continue

this progress and may provide additional new directions for research.

44. Buckner, R. L.; Koutstaal, W. Functional neuroimaging studies of encoding, priming,

and explicit memory retrieval. Proc-Natl-Acad-Sci-U-S-A. 1998 Feb 3; 95(3):

891-8; ISSN: 0027-8424.

UNITED-STATES. Human functional neuroimaging techniques provide a

powerful means of linking neural level descriptions of brain function and

cognition. The exploration of the functional anatomy underlying human memory

comprises a prime example. Three highly reliable findings linking memory-related

cognitive processes to brain activity are discussed. First, priming is accompanied

by reductions in the amount of neural activation relative to naive or unprimed task

performance. These reductions can be shown to be both anatomically and

functionally specific and are found for both perceptual and conceptual task

components. Second, verbal encoding, allowing subsequent conscious retrieval, is

associated with activation of higher order brain regions including areas within the

left inferior and dorsal prefrontal cortex. These areas also are activated by working

memory and effortful word generation tasks, suggesting that these tasks, often

discussed as separable, might rely on interdependent processes. Finally, explicit

(intentional) retrieval shares much of the same functional anatomy as the encoding

and word generation tasks but is associated with the recruitment of additional

brain areas, including the anterior prefrontal cortex (right > left). These findings

illustrate how neuroimaging techniques can be used to study memory processes

and can both complement and extend data derived through other means. More

recently developed methods, such as event-related functional MRI, will continue

this progress and may provide additional new directions for research.

45. Buklina, S. B. [Clinico-neuropsychological syndromes involving the human gyrus

cinguli]. Kliniko-neiropsikhologicheskie sindromy porazheniia poiasnoi izviliny

cheloveka. Zh-Nevrol-Psikhiatr-Im-S-S-Korsakova. 1997; 97(10): 11-6.

RUSSIA. There was performed clinical and neurophysiological observation of 41

patients with arteriovenous malformations (AVM) of gyrus cinguli. Disorders of

memory appeared to be the main manifestations before the operation in 38

patients, moreover they had the features of Korsakov's syndrome in 5 patients.

Autonomic and epileptic-like fits weren't quite characteristic. Memory

impairment was observed in 23 from 38 patients after operation, however there

weren't found any qualitatively new disorders. The first appearance of Korsakov's

syndrome after operation was found in 3 patients. The degree of the increase of

memory impairment correlated with the degree of the destruction of the gyrus

cinguli as well as with the massivity of AVM passing into corpus callosum.

Qualitative analysis of amnestic syndromes revealed that practically all the

patients had the alteration of the selectivity of the memory traces, inability to

keep in mind the meaning of the tale. It was accompanied by an absence of

criticism toward patients' own defects. Similar signs of disorders had close

resemblance with amnestic defects of the patients with frontal damages. That

testified the significance of both damages of frontal lobes and their connections in

formation of clinical pattern in human.

46. Bullitt, E.; Liu, A.; Pizer, S. M. Three-dimensional reconstruction of curves from

pairs of projection views in the presence of error. I. Algorithms. Med-Phys. 1997

Nov; 24(11): 1671-8; ISSN: 0094-2405.

UNITED-STATES. We have previously described an approach to 3D

intracerebral vascular reconstruction that uses an MRA as a reconstruction base.

Additional vessels seen only by angiography are added by segmenting 2D curves

from projection angiograms and reconstructing these curves into 3D, building

upon the MRA. Intracerebral vascular reconstruction is difficult for at least two

reasons. First, 2D curves must be associated on projection images even when the

human eye cannot do so. Second, 3D curves must be reconstructed in the presence

of errors such as misregistration, image distortion, and misdefinition of 2D curves.

This paper is the first of two that address the specific issue of reconstruction of a

3D curve from a given pair of 2D curves in the presence of error. The method

explicitly separates what can and cannot be determined from a pair of projection

views. It is also capable of recognizing interruptions produced by viewplane

errors, of continuing reconstruction beyond such interruptions, and of localizing

and estimating the magnitude of the interruptions. These measurements can also

be used to estimate the lengths of regional disparities between a pair of 2D curves,

leading to a quantitative estimate of the capacity of a pair of 2D curves to

combine to create a 3D object (match value). Match values can be used, in turn, as

part of the strategy for automatically associating pairs of 2D curves. This paper

provides methods for reconstructing a given pair of 2D curves into 3D in the

presence of error and for calculating match values. Error analysis is given in the

companion report.

47. Bullmore, E. T.; Rabe Hesketh, S.; Morris, R. G.; Williams, S. C.; Gregory, L.; Gray,

J. A.; Brammer, M. J. Functional magnetic resonance image analysis of a large-

scale neurocognitive network. Neuroimage. 1996 Aug; 4(1): 16-33; ISSN: 1053-

8119.

UNITED-STATES. Many "higher-order" mental functions are subserved by

large-scale neurocognitive networks comprising several spatially distributed and

functionally specialized brain regions. We here report statistical and graphical

methods of functional magnetic resonance imaging data analysis which can be used

to elucidate the functional relationships (i.e., connectivity and distance) between

elements of a neurocognitive network in a single subject. Data were acquired from

a normal right-handed volunteer during periodic performance of a task which

demanded visual and semantic processing of words and subvocalization of a

decision about the meaning of each word. Major regional foci of activation were

identified (by sinusoidal regression modeling and spatiotemporal randomization

tests) in left extrastriate cortex, angular gyrus, supramarginal gyrus, superior and

middle temporal gyri, lateral premotor cortex, and Broca's area. Principal

component (PC) analysis was initially undertaken by singular value

decomposition (SVD) of the "raw" time series observed at 170 activated voxels.

This revealed a large functional distance (negative connectivity) between visual

processing systems and all other brain regions in the space of the first PC. SVD of

a matrix of fitted time series, and a matrix of six sinusoidal regression parameters

estimated at each activated voxel, were developed as less noisy (more informative)

alternatives to SVD of the "raw" data. Canonical variate analysis of denoised data

was then used to clarify functional relationships between the major regional foci.

Visual input analysis systems (extrastriate cortex and angular gyrus) were

colocalized in the space of the first canonical variate (CV) and significantly

separated from all other brain regions. Semantic analysis systems (supramarginal

and temporal gyri) were colocalized and significantly separated in the space of the

second CV from the subvocal output system (Broca's area). These results are

provisionally interpreted in terms of underlying hemodynamic events and

cognitive psychological theory.

48. Burgund, E. D.; Marsolek, C. J. Letter-case-specific priming in the right cerebral

hemisphere with a form-specific perceptual identification task. Brain-Cogn. 1997

Nov; 35(2): 239-58; ISSN: 0278-2626.

UNITED-STATES. In a form-specific perceptual identification task, subjects

identify and write letter strings in the same letter case as they appear on a

computer display. Letter-case-specific repetition priming was observed in this

task when test items were presented directly to the right hemisphere, but not

when they were presented directly to the left hemisphere, similar to results in

previous word-stem completion experiments. This pattern of results was not

obtained in a standard perceptual identification task. Results indicate that a

specific visual-form subsystem, but not an abstract visual-form subsystem,

operates more effectively in the right hemisphere than in the left, and task

demands greatly affect which subsystems are recruited in different priming tests.

Copyright 1997 Academic Press.

49. Bussey, T. J.; Everitt, B. J.; Robbins, T. W. Dissociable effects of cingulate and

medial frontal cortex lesions on stimulus-reward learning using a novel Pavlovian

autoshaping procedure for the rat: implications for the neurobiology of emotion.

Behav-Neurosci. 1997 Oct; 111(5): 908-19; ISSN: 0735-7044.

UNITED-STATES. The effects of quinolinic acid-induced lesions of the anterior

cingulate, posterior cingulate, and medial frontal cortices on stimulus-reward

learning were investigated with a novel Pavlovian autoshaping procedure in an

apparatus allowing the automated presentation of computer-graphic stimuli to

rats (T. J. Bussey, J. L. Muir, & T. W. Robbins, 1994). White vertical rectangles

were presented on the left or the right of a computer screen. One of these

conditioned stimuli (the CS+) was always followed by the presentation of a

sucrose pellet; the other, the CS-, was never followed by reward. With training,

rats came to approach the CS+ more often than the CS-. Anterior cingulate cortex-

lesioned rats failed to demonstrate normal discriminated approach, making

significantly more approaches to the CS- than did sham-operated controls. Medial

frontal cortex-lesioned rats acquired the task normally but had longer overall

approach latencies. Posterior cingulate cortex lesions did not affect acquisition.

50. Cabeza, R.; McIntosh, A. R.; Tulving, E.; Nyberg, L.; Grady, C. L. Age-related

differences in effective neural connectivity during encoding and recall.

Neuroreport. 1997 Nov 10; 8(16): 3479-83; ISSN: 0959-4965.

ENGLAND. Age-related differences in brain activity may reflect local neural

changes in the regions involved or they may reflect a more global transformation

of brain function. To investigate this issue, we applied structural equation

modeling to the results of a positron emission tomography (PET) study in which

young and old adults encoded and recalled word pairs. In the young group there

was a shift from positive interactions involving the left prefrontal cortex during

encoding to positive interactions involving the right prefrontal cortex during recall,

whereas in the old group frontal interactions were mixed during encoding and

bilaterally positive during recall. The present results suggest that age-related

changes in neural activation are partly due to age-related changes in effective

connectivity in the neural network underlying the task.

51. Caldwell, F. T.; Graves, D. B.; Wallace, B. H. Studies on the mechanism of fever after

intravenous administration of endotoxin. J-Trauma. 1998 Feb; 44(2): 304-12;

ISSN: 0022-5282.

UNITED-STATES. BACKGROUND: The sequential events in fever production

after intravenous administration of lipopolysaccharide (LPS) remain unsettled and

controversial. Vessels of the organum vasculosum laminae terminalis (OVLT) lack

the tight junctions of the blood-brain barrier and allow substances of high

molecular weight to enter the interstitium but not the neuropil. The present

studies investigate the hypothesis that the OVLT is needed for fever production

after intravenous administration of LPS in the rat. METHODS: Electrolytic

lesions were produced in the OVLT of rats. After recovery, left carotid and right

atrial catheters were inserted, and 24 hours later calorimetry was performed.

Blood was drawn for baseline assay for cytokines and LPS after which LPS was

given intravenously, with studies continued for 5 hours, and additional blood

samples were drawn at 90 and 300 minutes. RESULTS: The maximal increment in

rectal temperature for the sham lesion LPS group (1.25 +/- 0.44 degrees C) was

significantly greater than for the sham-saline (-0.05 +/- 0.46 degrees C) and the

lesion-LPS groups (0.35 +/- 0.45 degrees C) for minutes 120 to 300. Ninety

minutes after LPS administration, serum levels of interleukin (IL)-6, tumor

necrosis factor-alpha, and LPS were significantly elevated (p < 0.0001) above

baseline for the sham-LPS and lesion-LPS groups. IL-1beta serum levels remained

below detection levels. CONCLUSION: Large lesions of the OVLT prevent

and/or attenuate fever due to LPS even though tumor necrosis factor-alpha and IL-

6 are greatly increased in serum. IL-1beta does not seem to be an endogenous

humoral mediator in this model.. 0; 0; 0; 0.

52. Campbell, A.; Villavicencio, A. T.; Yeghiayan, S. K.; Balikian, R.; Baldessarini, R. J.

Mapping of locomotor behavioral arousal induced by microinjections of dopamine

within nucleus accumbens septi of rat forebrain. Brain-Res. 1997 Oct 10; 771(1):

55-62; ISSN: 0006-8993.

NETHERLANDS. Dopamine (DA) at ca. ED50 (16 microg) or saline was

stereotaxically microinjected unilaterally 2 h after pretreatment with an MAO

inhibitor into left or right nucleus accumbens septi of 697 freely moving rats

(1394 injections) to define subregions involved in DA-induced behavioral arousal

throughout the anatomical extent of the accumbens. Locomotion was quantified

electronically and behavioral responses were assigned to histologically verified

injection sites; postural or stereotyped behaviors characteristic of DA injections

in caudate-putamen did not occur. Screening with 60 injections across mid-

accumbens (2.2-3.2 mm rostral to bregma) indicated that locomotion was elicited

non-homogeneously, and was particularly intense dorsomedially. Sites yielding

intense arousal and their inactive surround were mapped along the rostrocaudal

axis (1.4-4.2 mm anterior to bregma) in coronal sections. Responses to DA

showed lateral symmetry and were similar across rostrocaudal levels, with intense

responses in dorsomedial accumbens along its border with the caudate-putamen.

This functional localization does not coincide closely with reported distributions

of DA or its receptors, nor with histologically or histochemically defined core-

shell regions of this limbic structure. Nucleus accumbens in rat brain thus appears

to be organized functionally into distinct subregions differing markedly in ability

to produce locomotor hyperactivity in response to exogenous DA.. 51-61-6.

53. Camuscu, H.; Dujovny, M.; Abd, el Bary T.; Beristain, X.; Vinas, F. C.

Microanatomy of the perforators of the anterior communicating artery complex.

Neurol-Res. 1997 Dec; 19(6): 577-87; ISSN: 0161-6412.

ENGLAND. We describe the microanatomy of the perforating arteries arising

from the anterior communicating artery complex (5 mm distal of the anterior

cerebral artery, the anterior communicating artery, and 5 mm proximal of the distal

anterior cerebral artery). Thirteen unfixed human brains were used in this study.

The origin and number of perforators are described, as is the site of brain

penetration, and results are correlated with previous studies. The hemodynamics

of blood flow in relation to the formation of an anterior communicating artery

aneurysm and different surgical approaches are mentioned. The

neuropsychological outcome after aneurysm clipping with regards to the pattern

of blood supply from the anterior cerebral artery complex is also discussed.

54. Camuscu, H.; Dujovny, M.; Abd, el Bary T.; Beristain, X.; Vinas, F. C.

Microanatomy of the perforators of the anterior communicating artery complex.

Neurol-Res. 1997 Dec; 19(6): 577-87; ISSN: 0161-6412.

ENGLAND. We describe the microanatomy of the perforating arteries arising

from the anterior communicating artery complex (5 mm distal of the anterior

cerebral artery, the anterior communicating artery, and 5 mm proximal of the distal

anterior cerebral artery). Thirteen unfixed human brains were used in this study.

The origin and number of perforators are described, as is the site of brain

penetration, and results are correlated with previous studies. The hemodynamics

of blood flow in relation to the formation of an anterior communicating artery

aneurysm and different surgical approaches are mentioned. The

neuropsychological outcome after aneurysm clipping with regards to the pattern

of blood supply from the anterior cerebral artery complex is also discussed.

55. Carlsson, G. Memory for words and drawings in children with hemiplegic cerebral

palsy. Scand-J-Psychol. 1997 Dec; 38(4): 265-73; ISSN: 0036-5564.

ENGLAND. A list-learning paradigm was used to study learning and memory of

verbal and figurative material in children with right versus left-sided hemiplegic

cerebral palsy. Thirty-one children with right (n = 18), or left (n = 13) congenital

hemiplegia were compared with normal controls (n = 19). All children had normal

intelligence (IQ > 80), and were attending standard schools. The inclusion criteria

for the two hemiplegic groups were; no epilepsy, no hearing or visual

impairments, and a mild to moderate hemiparesis. The aim of this study was to

explore material-specific (words and drawings) differences in the acquisition, recall

and serial position effects in children with an early unilateral brain lesion. The left-

hemisphere impaired (i.e. right hemiplegia) group showed impaired acquisition for

drawings, as compared with the normal controls. There was also a material-

specific difference in the serial position effect for all three groups. Learning of

words followed the primacy principle, whereas the learning of drawings followed

the recency principle. There were no group-differences in delayed-recall (i.e. long-

term memory) for either words or drawings. The results are discussed in terms of

acquisition and retention of verbal and figurative materials in relation to lesion side

and size.

56. Chang, J.; Jozwiak, R.; Wang, B.; Ng, T.; Ge, Y. C.; Bolton, W.; Dwyer, D. E.;

Randle, C.; Osborn, R.; Cunningham, A. L.; Saksena, N. K. Unique HIV type 1

V3 region sequences derived from six different regions of brain: region-specific

evolution within host-determined quasispecies. AIDS-Res-Hum-Retroviruses.

1998 Jan 1; 14(1): 25-30; ISSN: 0889-2229.

UNITED-STATES. HIV type 1 viral quasispecies were amplified by polymerase

chain reaction (PCR) in the hypervariable V3 region of gp120 from six different

regions of the brain (right and left frontal; right and left parietal; and right and left

occipital) and from the peripheral blood mononuclear cells (PBMCs) of a patient

who died of AIDS dementia complex (ADC). Cloning and sequencing of the entire

V3 region suggested the presence of genetically unique sequences in different

regions of the brain. In contrast, the blood-derived viral quasispecies carried

homogeneous sequences that were characterized by a single octapeptide crest

motif (HLGPGSAF), a motif important in viral fusion. The brain-derived viral

strains showed extensive sequence heterogeneity and the presence of seven

different octapeptide and four different tetrapeptide crest motifs (HIGPGRAF,

RIGPGRAF, HIGPGSAI, HLGPGSAF, HIGPESAI, HLGPESAI, and

YLRPGSAF). In addition, the brain-derived strains were also characterized by

variable net V3 loop charge and hydrophilicity, along with distinct amino acid

changes specific to different brain regions. Together, the sequence and

phylogenetic analyses are unique in identifying the complexity of a viral

quasispecies and its independent regional evolution within the brain compartment.

Uniquely divergent viral strains were identified in the frontal regions and their

presence was further supported by the presence of multinucleated giant cells

(characteristic of HIV encephalopathy) predominantly in the left and right frontal

regions. In summary, these analyses suggest that genetically different populations

of HIV-1 may be present in different brain compartments and confirm that

specific neurotropic variants may exist.. 0; 0; 0.

57. Chatterjee, A.; Yapundich, R.; Mennemeier, M.; Mountz, J. M.; Inampudi, C.; Pan,

J. W.; Mitchell, G. W. Thalamic thought disorder: on being "a bit addled". Cortex.

1997 Sep; 33(3): 419-40; ISSN: 0010-9452.

ITALY. Humans can generate and maintain relatively coherent trains of thought

in natural discourse. The neural mediation of this ability and the phenomenology

of its breakdown are not well understood. We report a case of a woman with

paramedian thalamic strokes involving the mammillothalamic tract, intralaminar

nuclei, parts of the dorsomedial and ventral lateral nuclei bilaterally. She presented

with a dense amnesia and confusion typical of the syndrome of bilateral

paramedian thalamic infarcts. Her Tc-99m HMPAO brain SPECT scan showed

decreased thalamic and basal ganglia blood flow. General diminution of cerebral

blood flow and areas of further diminution in the right frontal, left temporal and

left temporoparietal regions were also observed. Although her amnesia was

characteristic of diencephalic amnesia, her most striking clinical feature was a

bizarre, disconnected and at times incoherent speech output. Analysis of her

speech revealed relatively preserved lexical and morpho-syntactic linguistic

production. By contrast, analysis of the macrostructure of her discourse revealed

frequent unpredictable topic shifts that were completely unconstrained by

contextual factors. Many of her shifts were intrusions from previous topics. We

interpret her severely disordered speech output as representing the surface

manifestations of a thought disorder (rather than as a language disorder per se)

characterized by an inability to maintain and appropriately shift themes that

normally guide discourse. Median and intralaminar thalamic nuclei appear to be

critical for the neurophysiologic regulation of thalamocortical and striatocortical

circuits, which in turn may be critical for the functional regulation of contextually

appropriate transitions of thought.

58. Chen, Bee CH; Frostig, R. D. Variability and interhemispheric asymmetry of single-

whisker functional representations in rat barrel cortex. J-Neurophysiol. 1996 Aug;

76(2): 884-94; ISSN: 0022-3077.

UNITED-STATES. 1. The rat whisker-to-barrel system was used to investigate

the variability and interhemispheric asymmetry in the functional organization of

primary somatosensory cortex as assessed with intrinsic signal optical imaging.

The areal extent of whisker D1 functional representation was determined for both

the left and right barrel cortex of each of 10 adult male rats. The average size of

whisker D1 functional representation and the amount of variability away from

this average across animals were determined. In addition, interhemispheric

asymmetry was addressed at both the population level and the individual level.

The degree of side preference for thigmotactic scanning (typical whisker-related

rodent behavior) was determined for each rat in an attempt to find a behavioral

correlate for the degree of interhemispheric asymmetry in the size of whisker D1

functional representation. 2. The average areal extent of whisker D1 functional

representation (defined as area at half-height) was large (1.95 +/- 0.14 mm2, mean

+/- SE, N = 10 rats), suggesting that stimulation of a single whisker evokes

activity over a large cortical area that includes other whisker representations. 3.

The average size of whisker D1 functional representation was not significantly

different between the left (1.86 +/- 0.21 mm2) and right (2.04 +/- 0.15 mm2)

hemispheric side, suggesting that interhemispheric functional asymmetry of barrel

cortex is not systematic toward a specific hemispheric side at the population

level. 4. The degree of variability in the size of whisker D1 functional

representation from the left hemisphere ranged between 54.6% smaller than to

50.6% larger than the left average areal extent. A large degree of variability was

also observed for the right D1 representation, 37.6% smaller than to 34.9% larger

than the right average areal extent. Thus it appears that a large variability in the

size of unmanipulated single-whisker functional representations exists across

animals from the same species and is not exclusive to a particular hemispheric

side. 5. In 5 of 10 rats, the size of whisker D1 functional representation between

the two hemispheres differed by > or = 25% within an individual animal. Of these

five rats, four had a larger representation in their right hemisphere. The degree and

direction of behavioral asymmetry was not linearly correlated with the

interhemispheric asymmetry in the size of D1 functional representation (r =

0.494). 6. The large size of a single-whisker functional representation as defined

with intrinsic signal optical imaging is discussed with respect to previous

anatomic and 2-deoxyglucose autoradiography studies, whereas the large

variability in this size across animals is discussed with respect to the individuality

of each animal. In addition, the results of the present study have implications for

projects that plan to investigate relative changes in the size of single-whisker

functional representations.

59. Chen, R.; Cohen, L. G.; Hallett, M. Role of the ipsilateral motor cortex in voluntary

movement. Can-J-Neurol-Sci. 1997 Nov; 24(4): 284-91; ISSN: 0317-1671.

CANADA. The ipsilateral primary motor cortex (M1) plays a role in voluntary

movement. In our studies, we used repetitive transcranial magnetic stimulation

(rTMS) to study the effects of transient disruption of the ipsilateral M1 on the

performance of finger sequences in right-handed normal subjects. Stimulation of

the M1 ipsilateral to the movement induced timing errors in both simple and

complex sequences performed with either hand, but with complex sequences, the

effects were more pronounced with the left-sided stimulation. Recent studies in

both animals and humans have confirmed the traditional view that ipsilateral

projections from M1 to the upper limb are mainly directed to truncal and

proximal muscles, with little evidence for direct connections to distal muscles. The

ipsilateral motor pathway appears to be an important mechanism for functional

recovery after focal brain injury during infancy, but its role in functional recovery

for older children and adults has not yet been clearly demonstrated. There is

increasing evidence from studies using different methodologies such as rTMS,

functional imaging and movement-related cortical potentials, that M1 is involved

in ipsilateral hand movements, with greater involvement in more complex tasks

and the left hemisphere playing a greater role than the right.

60. Chen, W.; Kato, T.; Zhu, X. H.; Strupp, J.; Ogawa, S.; Ugurbil, K. Mapping of lateral

geniculate nucleus activation during visual stimulation in human brain using fMRI.

Magn-Reson-Med. 1998 Jan; 39(1): 89-96; ISSN: 0740-3194.

UNITED-STATES. Functional magnetic resonance imaging has been successfully

used to map the activation in the lateral geniculate nucleus (LGN) in both

hemispheres as well as the primary visual cortex (V1) during a checkerboard visual

stimulation. The average blood oxygenation level dependent (BOLD) change in

LGN was less than that in V1. However, the BOLD temporal responses were

similar between LGN and V1. The activation in the pulvinar nucleus during visual

perception was also detected, and its activated location could be separated from

LGN in 3D images. The LGN activation between intersubject and intrasubject

multiple trials was compared. The results demonstrate that fMRI can reliably and

robustly detect small subcortical nucleus activation in the human brain.

61. Cho, S.; Jones, D.; Reddick, W. E.; Ogg, R. J.; Steen, R. G. Establishing norms for

age-related changes in proton T1 of human brain tissue in vivo. Magn-Reson-

Imaging. 1997; 15(10): 1133-43; ISSN: 0730-725X.

UNITED-STATES. The goal of this study was to determine the expected normal

range of variation in spin-lattice relaxation time (T1) of brain tissue in vivo, as a

function of age. A previously validated precise and accurate inversion recovery

method was used to map T1 transversely, at the level of the basal ganglia, in a

study population of 115 healthy subjects (ages 4 to 72; 57 male and 58 female).

Least-squares regression analysis shows that T1 varied as a function of age in

pulvinar nucleus (R2 = 56%), anterior thalamus (R2 = 51%), caudate (R2 = 50%),

frontal white matter (R2 = 47%), optic radiation (R2 = 39%), putamen (R2 =

36%), genu (R2 = 22%), occipital white matter (R2 = 20%) (all p < 0.0001), and

cortical gray matter (R2 = 53%) (p < 0.001). There were no significant differences

in T1 between men and women. T1 declines throughout adolescence and early

adulthood, to achieve a minimum value in the fourth to sixth decade of life, then

T1 begins to increase. Quantitative magnetic resonance imaging provides evidence

that brain tissue continues to change throughout the lifespan among healthy

subjects with no neurologic deficits. Age-related changes follow a strikingly

different schedule in different brain tissues; white matter tracts tend to reach a

minimum T1 value, and to increase again, sooner than do gray matter tracts. Such

normative data may prove useful for the early detection of brain pathology in

patients.. 0.

62. Chokron, S.; Bartolomeo, P. Patterns of dissociation between left hemineglect and

deviation of the egocentric reference. Neuropsychologia. 1997 Nov; 35(11): 1503-

8; ISSN: 0028-3932.

ENGLAND. Sixteen control subjects and six right brain-damaged patients with

left hemiparesis (three showing signs of left unilateral neglect, three with no signs

of neglect) performed a straight-ahead pointing task with their right hand while

blindfolded. The aim was to test the hypothesis that the egocentric reference

shows significant ipsilesional deviation in left neglect patients. We found no

correlation between the position of the egocentric reference and the presence of

neglect signs. Neglect patients, like non-neglect patients, showed leftward,

rightward or no significant deviation when pointing straight ahead. Results are

discussed with reference to egocentric hypotheses of neglect and experimental

remission of neglect.

63. Clarisse, J.; Soto Ares, G.; Pertuzon, B.; Ayachi, M.; Francke, J. P. [Identification of

the central sulcus using the scanner and MRI]. Reperage du sillon central en

scanner et en IRM. J-Neuroradiol. 1997 Oct; 24(3): 187-204; ISSN: 0150-9861.

FRANCE. Methods to directly and indirectly identify the central sulcus are

presented. In the axial plan, direct method is remarkable but obviously requires

good visualization of the sulci in the central region. Sulci are readily visible in 90%

of the cases on CT scans and in 50% of the cases on MRI. The method can also

be applied when tumoral development erases the cerebral sulci by direct lecture of

the controlateral rolandic region and right-left transfer. Within the precision limits

of the method, it can be considered that the central sulci are symmetrical. The

main signs are: the relative morphologies of the superior frontal sulcus and the

precentral sulcus, the hook-shaped aspect of the middle part of the central sulcus,

the internal end of the central sulcus projection anteriorly to the pars marginalis,

the bifid nature of the internal end of the posterior central sulcus contouring the

pars marginalis, and the lesser thickness of the posterior central gyrus compared

with the precentral gyrus. The indirect method is less precise and is used when

the direct method is unsuccessful. The central sulcus is identified on the sagittal

images and, using the lateral view of the skull as a reference image, the topographic

information is transferred to the axial images.

64. Cohen, H. L.; Porjesz, B.; Begleiter, H.; Wang, W. Neurophysiological correlates of

response production and inhibition in alcoholics. Alcohol-Clin-Exp-Res. 1997

Nov; 21(8): 1398-406; ISSN: 0145-6008.

UNITED-STATES. Scalp recordings of the P300 component of the event-related

potential were made from a group of medication-free, chronic male alcoholics and

a control group, participating in a visual Go/No Go reaction time paradigm.

Subjects were presented with large and small forms of the letters T and V. The

large forms (Go stimuli) required a button press with either the left or right hand,

whereas the small forms (NO Go stimuli) required response inhibition. Recordings

were made from 31 electrodes that, for statistical analyses, were grouped into five

regions: frontal, central, parietal, occipital, and temporal. The results indicated

that, in each of the five regions, both Go and NO Go response amplitudes were

larger in the controls than in the alcoholics. No group differences in latency were

observed in any region. Surface energy (Wang et al., Brain Topogr. 6:193-202,

1994) magnitudes paralleled P300 amplitudes and in the controls, compared with

the alcoholics, were larger during both Go and No Go trials. Our findings suggest

that abstinent, chronic alcoholics differ electro-physiologically from control

individuals. These differences are manifested as widespread reductions in P300

amplitudes during the performance of a simple information processing paradigm.

The reduced amplitudes may reflect a deficiency in an inhibitory mechanism

proposed to underlie P300 generation.

65. Cohen, J. E.; Garrote, M. Central neurocytoma with symptomatic paraventricular

cyst: case report. Neurol-Res. 1998 Jan; 20(1): 89-92; ISSN: 0161-6412.

ENGLAND. This is the first report of the occurrence of a central neurocytoma

and a symptomatic paraventricular cyst; this entity may have particular surgical

implications. A 37-year-old male was admitted with a four month history of

dizziness and gait instability. He subsequently developed increasing weakness of

his left arm and leg. An unenhanced computed tomography scan revealed a

hyperdense mass in the right lateral ventricle with a paraventricular cystic lesion

in the frontoparietal white matter. MR images showed the origin and extent of the

lesion more completely. A frontoparietal craniotomy with a transfrontal

transcystic approach allowed resection of the tumor. Intraventricular tumors

continue to present a major challenge for neurosurgeons because of their depth and

the important surrounding structures. We report the use of a well-known

neurosurgical strategy, the transcystic approach, for gross removal of a

neurocytoma located in the ventricles.

66. Cole, D. J.; Nary, J. C.; Reynolds, L. W.; Patel, P. M.; Drummond, J. C.

Experimental subarachnoid hemorrhage in rats: effect of intravenous alpha-alpha

diaspirin crosslinked hemoglobin on hypoperfusion and neuronal death.

Anesthesiology. 1997 Dec; 87(6): 1486-93; ISSN: 0003-3022.

UNITED-STATES. BACKGROUND: Hemodilution with diaspirin crosslinked

hemoglobin (DCLHb) ameliorates occlusive cerebral ischemia. However,

subarachnoid hemoglobin has been implicated as a cause of cerebral

hypoperfusion. The effect of intravenous DCLHb on cerebral perfusion and

neuronal death after experimental subarachnoid hemorrhage was evaluated.

METHODS: Rats (n = 48) were anesthetized with isoflurane and subarachnoid

hemorrhage was induced by injecting 0.3 ml of autologous blood into the cistema

magna. Each animal received one of the following regimens: Control, no hematocrit

manipulation; DCLHb, hematocrit concentration decreased to 30% with DCLHb;

or Alb, hematocrit concentration decreased to 30% with human serum albumin.

The experiments had two parts, A and B. In part A, after 20 min, cerebral blood

flow (CBF) was assessed with 14C-iodoantipyrine autoradiography. In part B,

after 96 h, in separate animals, the number of dead neurons was determined in

predetermined coronal sections by hematoxylin and eosin staining. RESULTS:

Cerebral blood flow was greater for the DCLHb group than for the control group;

and CBF was greater for the Alb group than the other two groups (P < 0.05). In

one section, CBF was 45.5 +/- 10.9 ml x 100 g(-1) x min(-1) (mean +/- SD) for the

control group, 95.3 +/- 16.6 ml x 100 g(-1) x min(-1) for the DCLHb group, and

138.1 +/- 18.7 ml x 100 g(-1) x min(-1) for the Alb group. The number of dead

neurons was less in the Alb group (611 +/- 84) than in the control group (1,097

+/- 211), and was less in the DCLHb group (305 +/- 38) than in the other two

groups (P < 0.05). CONCLUSIONS: These data support a hypothesis that

hemodilution decreases hypoperfusion and neuronal death after subarachnoid

hemorrhage. The data do not support the notion that intravascular molecular

hemoglobin has an adverse effect on brain injury after subarachnoid hemorrhage..

0; 0; 50-78-2.

67. Colon, G. P.; Quint, D. J.; Dickinson, L. D.; Brunberg, J. A.; Jamerson, K. A.; Hoff,

J. T.; Ross, D. A. Magnetic resonance evaluation of ventrolateral medullary

compression in essential hypertension. J-Neurosurg. 1998 Feb; 88(2): 226-31;

ISSN: 0022-3085.

UNITED-STATES. OBJECT: The authors designed a blinded prospective study

comparing patients with essential hypertension to patients without hypertension

in which magnetic resonance (MR) imaging was used to evaluate the role of lateral

medullary compression by adjacent vascular structures as a cause of neurogenic

hypertension. METHODS: Patients with documented essential hypertension

were recruited to undergo thin-slice axial brainstem MR imaging evaluation.

Nonhypertensive (control) patients scheduled to undergo MR imaging for other

reasons also underwent thin-slice MR imaging to form a basis for comparison.

Magnetic resonance images obtained in patients from the hypertensive (30

patients) and the control (45 patients) groups were then compared by four

independent reviewers (two neuroradiologists and two neurosurgeons) who were

blinded to the patients' diagnosis and hypertensive status. Images were reviewed

with regard to left versus right vertebral artery (VA) dominance, compression of

the medulla on the left and/or right side, and brainstem rotation. Medullary

compression was graded as either vessel contact without associated brainstem

deformity or vessel contact with associated brainstem deformity.

CONCLUSIONS: There was a tendency toward left VA dominance in the

hypertensive group compared with the control group, although a significant

difference was shown by only one of the four reviewers. There were no

differences in brainstem compression or rotation between the hypertensive and

nonhypertensive groups. These results are contrary to those of recently published

studies in which MR imaging and/or MR angiography revealed lateral brainstem

vascular compression in hypertensive patients but not in nonhypertensive

(control) patients. Reasons for this discrepancy are discussed. On the basis of

their own experience and that of others, the authors believe that neurogenic

hypertension does exist. However, thin-slice MR imaging may not be a reliable

method for detecting neurovascularly induced essential hypertension and the

prevalence of neurovascular compression as the source of hypertension may be

overestimated when using current imaging techniques.

68. Cornford, E. M.; Hyman, S.; Cornford, M. E.; Landaw, E. M.; Delgado Escueta, A.

V. Interictal seizure resections show two configurations of endothelial Glut1

glucose transporter in the human blood-brain barrier. J-Cereb-Blood-Flow-Metab.

1998 Jan; 18(1): 26-42; ISSN: 0271-678X.

UNITED-STATES. Immunogold electron microscopy was used to analyze and

quantify the Glut1 glucose transporter in brain tissue from five patients

undergoing surgery for treatment of seizures. Samples were prepared from two

different regions of each resection: (1) the most actively spiking epileptogenic site,

and (2) the least actively spiking region, as indicated by intraoperative EEG

monitoring. Two configurations of endothelial cell Glut1 were observed. About

one half of the capillary profiles examined displayed abundant Glut1

immunoreactivity on both luminal and abluminal endothelial membranes. In the

remainder of the profiles, reduced Glut1 labeling was seen, but adjacent

erythrocyte membranes remained highly Glut1 immunoreactive, suggesting that

reduced endothelial Glut1 reactivity was not attributable to method artifacts.

Immunogold studies using antisera to human glial fibrillary acidic protein and

human serum albumin demonstrated increased quantities of these two epitopes in

the extravascular regions in which more EEG spiking activity had been

demonstrated. These observations were consistent with the hypotheses that

capillary integrity was more compromised, and gliosis was quantitatively

increased, in the more actively spiking region of the resection. Altered glucose

transporter activity in the blood-brain barrier was characterized by a bimodal

Glut1 distribution in which the smaller (type B) endothelial cells displayed low

Glut1 immunoreactivity, whereas adjacent (and even contiguous) larger (type A)

endothelial cells showed 5- to 10-fold greater expression of membrane Glut1

transporter protein. Because this transporter facilitates glucose entry to the brain,

small pericapillary volumes of brain tissue may have quite different

concentrations of glucose. We hypothesize that in complex partial seizures and

other forms of brain insult, an alteration of blood-brain barrier Glut1 glucose

transporter activity is indicated by the appearance of these two subpopulations

of endothelial cells. In comparison with previous studies of human brain

capillaries in hemangioblastoma and brain injury, endothelial Glut1 density was

apparently reduced (interictally) in affected temporal lobes of patients with

complex partial seizures.. 0; 0; 50-99-7.

69. Courtney, S. M.; Petit, L.; Maisog, J. M.; Ungerleider, L. G.; Haxby, J. V. An area

specialized for spatial working memory in human frontal cortex. Science. 1998

Feb 27; 279(5355): 1347-51; ISSN: 0036-8075.

UNITED-STATES. Working memory is the process of maintaining an active

representation of information so that it is available for use. In monkeys, a

prefrontal cortical region important for spatial working memory lies in and around

the principal sulcus, but in humans the location, and even the existence, of a region

for spatial working memory is in dispute. By using functional magnetic resonance

imaging in humans, an area in the superior frontal sulcus was identified that is

specialized for spatial working memory. This area is located more superiorly and

posteriorly in the human than in the monkey brain, which may explain why it was

not recognized previously.

70. Covenas, R.; de Leon, M.; Narvaez, J. A.; Aguirre, J. A.; Tramu, G.; Gonzalez Baron,

S. ACTH/CLIP immunoreactivity in the cat brain stem. Peptides. 1997; 18(7):

965-70; ISSN: 0196-9781.

UNITED-STATES. The distribution of adrenocorticotropin

hormone/corticotropin-like intermediate lobe peptide was studied in the cat brain

stem, using an indirect immunoperoxidase technique. No immunoreactive cell

bodies were observed. However, a high density of immunoreactive fibers was

found in the periaqueductal gray, the dorsal nucleus of the raphe, the locus

coeruleus, and the marginal nucleus of the brachium conjunctivum. A moderate

density was found in the central linear nucleus, the central tegmental field, the

Kolliker-Fuse nucleus, the inferior central nucleus, and the postpyramidal nucleus

of the raphe. A low density was found in the superior and inferior colliculi, the

interpeduncular nucleus, the nucleus sagulum, the superior central nucleus, the

cuneiform nucleus, the accessory dorsal tegmental nucleus, the nucleus of the

solitary tract, the dorsal motor nucleus of the vagus, and the paralemniscal,

magnocellular, gigantocellular, and lateral tegmental fields. Moreover, single

immunoreactive fibers were observed in numerous nuclei of the cat brain stem. In

comparison with previous studies carried out in the same region of the cat, as well

as the rat and the human, our results point to a more widespread distribution of

adrenocorticotropin hormone/corticotropin-like intermediate lobe peptide

immunoreactive structures in the cat brain stem. This widespread distribution

indicates that the peptide might be involved in several physiological functions of

the cat brain stem.. 0; 53917-42-3; 9002-60-2.

71. Cox, R. W.; Hyde, J. S. Software tools for analysis and visualization of fMRI data.

NMR-Biomed. 1997 Jun; 10(4-5): 171-8; ISSN: 0952-3480.

ENGLAND. The tools needed for analysis and visualization of three-dimensional

human brain functional magnetic resonance image results are outlined, covering the

processing categories of data storage, interactive vs batch mode operations,

visualization, spatial normalization (Talairach coordinates, etc.), analysis of

functional activation, integration of multiple datasets, and interface standards. One

freely available software package is described in some detail. The features and

scope that a generally useful and extensible fMRI toolset should have are

contrasted with what is available today. The article ends with a discussion of how

the fMRI research community can cooperate to create standards and develop

software that meets the community's needs.. 7782-44-7.

72. Crivello, F.; Tzourio, N.; Poline, J. B.; Woods, R. P.; Mazziotta, J. C.; Mazoyer, B.

Intersubject variability in functional neuroanatomy of silent verb generation:

assessment by a new activation detection algorithm based on amplitude and size

information. Neuroimage. 1995 Dec; 2(4): 253-63; ISSN: 1053-8119.

UNITED-STATES. We present an experimental evaluation of a new algorithm

for the detection of activated areas in brain functional maps. The new algorithm,

named HMSD, is based on a hierarchical multiscale description of the difference

image in terms of connected objects. Size and magnitude of each object are

simultaneously tested with respect to a bidimensional frequency distribution

derived using Monte-Carlo simulations under the null hypothesis. In the present

work. HMSD was applied to the analysis of a silent verb generation PET

activation protocol conducted in six right-handed subjects. Applied to single-

subject data. HMSD reveals activation located in the left inferior frontal gyrus in

three subjects (two in the pars opercularis, one in the pars triangularis), and in the

pars opercularis of the right inferior frontal gyrus in one case, the latter being

combined to a crossed cerebellar activation. Overall, single-case results were

consistent with the analyses of stereotactically averaged data. Despite a 2D

implentation. HMSD detection performances of averaged data were better than

that obtained with the 2D version of statistical parametric mapping (SPM) and

comparable to that of the 3D version of SPM.

73. da Silva, E. A.; Chugani, D. C.; Muzik, O.; Chugani, H. T. Landau-Kleffner

syndrome: metabolic abnormalities in temporal lobe are a common feature. J-

Child-Neurol. 1997 Nov; 12(8): 489-95; ISSN: 0883-0738.

UNITED-STATES. Landau-Kleffner syndrome (acquired epileptic aphasia) is

characterized by language regression following normal acquisition of language

skills, accompanied by epileptiform abnormalities on the electroencephalogram

(EEG) with or without clinical seizures. Continuous spikes and waves during

slow wave sleep may be seen on the EEG, but are not required to make the

diagnosis. Structural neuroimaging with computed tomography (CT) and magnetic

resonance imaging (MRI) is typically normal. We have evaluated 17 children (aged

2.4 to 10.6 yr) with Landau-Kleffner syndrome using positron emission

tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) in order to

determine whether there are metabolic abnormalities common to this syndrome.

Patients were awake for the uptake period of FDG, and the EEG was monitored.

On a visual analysis of the PET images, patients showed metabolic abnormalities

in the temporal lobes. Two children had focal hypermetabolism in the left

temporal cortex, one of whom also showed right temporal cortex

hypometabolism. The remaining patients (n = 15) showed bilateral temporal

hypometabolism, and comparison of these patients with a neurologically normal

age-matched control group (n = 8) demonstrated significantly reduced glucose

metabolism bilaterally in middle temporal gyrus (P < .02). In addition, other

cortical regions displayed hypometabolism, although these regions were not

consistently abnormal in all patients. The finding of temporal lobe abnormalities

in all Landau-Kleffner syndrome patients suggests that temporal lobe structures

are important in the pathophysiology of this syndrome, whereas the presence of

additional cortical abnormalities in many patients indicates that extensive brain

functional disturbances are common.. 0; 50-99-7; 63503-12-8.

74. Dassonville, P.; Zhu, X. H.; Uurbil, K.; Kim, S. G.; Ashe, J. Functional activation in

motor cortex reflects the direction and the degree of handedness. Proc-Natl-Acad-

Sci-U-S-A. 1997 Dec 9; 94(25): 14015-8; ISSN: 0027-8424.

UNITED-STATES. Handedness is the clearest example of behavioral

lateralization in humans. It is not known whether the obvious asymmetry

manifested by hand preference is associated with similar asymmetry in brain

activation during movement. We examined the functional activation in cortical

motor areas during movement of the dominant and nondominant hand in groups of

right-handed and left-handed subjects and found that use of the dominant hand

was associated with a greater volume of activation in the contralateral motor

cortex. Furthermore, there was a separate relation between the degree of

handedness and the extent of functional lateralization in the motor cortex. The

patterns of functional activation associated with the direction and degree of

handedness suggest that these aspects are independent and are coded separately in

the brain.

75. DeCarli, C.; Hatta, J.; Fazilat, S.; Fazilat, S.; Gaillard, W. D.; Theodore, W. H.

Extratemporal atrophy in patients with complex partial seizures of left temporal

origin. Ann-Neurol. 1998 Jan; 43(1): 41-5; ISSN: 0364-5134.

UNITED-STATES. Total cerebral, temporal lobe, hippocampal, caudate, and

lenticular nuclei volumes were quantified from magnetic resonance images of 21

patients with left temporal lobe epilepsy and medically intractable complex

partial seizures. These regional brain volumes were compared with the same

measures in 19 controls. No significant differences in total cerebral, left temporal

lobe, right temporal lobe, or total temporal lobe volumes were found. As expected,

left hippocampal volumes were significantly smaller in the patients with epilepsy

than in control subjects. The left hippocampus-to-right hippocampus volume

ratio was significantly lower in patients than in control subjects. In addition to left

hippocampal volumes, mean left thalamic, left caudate, and bilateral lenticular

volumes were significantly smaller in the patients with epilepsy than in control

subjects. The left-to-right thalamic volume ratio was also significantly lower in the

patients with epilepsy compared with control subjects, but there were no

significant group differences in caudate or lenticular ratios. These results show

that medically intractable temporal lobe epilepsy is associated with volume loss in

brain structures outside the presumably involved hippocampus. The

pathophysiological significance of our findings is uncertain. They could be related

to the underlying cause of the disorder. However, volume loss also may reflect

damage due to involvement of these structures in recurrent seizure activity.

76. Decety, J.; Grezes, J.; Costes, N.; Perani, D.; Jeannerod, M.; Procyk, E.; Grassi, F.;

Fazio, F. Brain activity during observation of actions. Influence of action content

and subject's strategy. Brain. 1997 Oct; 120( Pt 10): 1763-77; ISSN: 0006-8950.

ENGLAND. PET was used to map brain regions that are associated with the

observation of meaningful and meaningless hand actions. Subjects were scanned

under four conditions which consisted of visually presented actions. In each of the

four experimental conditions, they were instructed to watch the actions with one

of two aims: to be able to recognize or to imitate them later. We found that

differences in the meaning of the action, irrespective of the strategy used during

observation, lead to different patterns of brain activity and clear left/right

asymmetries. Meaningful actions strongly engaged the left hemisphere in frontal

and temporal regions while meaningless actions involved mainly the right

occipitoparietal pathway. Observing with the intent to recognize activated

memory-encoding structures. In contrast, observation with the intent to imitate

was associated with activation in the regions involved in the planning and in the

generation of actions. Thus, the pattern of brain activation during observation of

actions is dependent both on the nature of the required executive processing and

the type of the extrinsic properties of the action presented.

77. Deckel, A. W. Hemispheric control of territorial aggression in Anolis carolinensis:

effects of mild stress. Brain-Behav-Evol. 1998; 51(1): 33-9; ISSN: 0006-8977.

SWITZERLAND. Previous work has demonstrated that the brain of Anolis

carolinensis is functionally split, in that the left and right eyes project

predominantly to the contralateral hemisphere, and as there are minimal

connections between the left and right hemispheres. Using this model, the current

experiment examined the effect of mild acute stress on hemispheric regulation of

territorial aggression. Thirteen adult male Anolis were paired with an antagonistic

males, and eye use and behavioral responses were repeatedly measured during 3

minute behavioral trials. Trials were conducted either after exposure to mild

stress, produced by handling the subject, or without stress, and they were run

either in the subject's home cage or in a cage foreign to the subject. Left eye

preference for aggressive movements was found during the trials run in the non-

stressed conditions (p < 0.05). Conversely, stressed subjects showed a reduction

in left eye/right hemisphere mediated aggressive movements relative to the non-

stressed subjects but no changes in right eye/left hemisphere aggression. This

effect was independent of whether or not the subject was in its home or a foreign

cage. No laterality in aggressive responding was found when the subjects were

placed in separate cages with visual contact. These findings suggest that territorial

aggression in Anolis is preferentially initiated and processed by the left eye/right

hemisphere but is subject to right-hemispheric inhibition following exposure to

acute mild stress.

78. Dehaene, S.; Dupoux, E.; Mehler, J.; Cohen, L.; Paulesu, E.; Perani, D.; van, de

Moortele PF; Lehericy, S.; Le Bihan, D. Anatomical variability in the cortical

representation of first and second language. Neuroreport. 1997 Dec 1; 8(17):

3809-15; ISSN: 0959-4965.

ENGLAND. Functional magnetic resonance imaging was used to assess inter-

subject variability in the cortical representation of language comprehension

processes. Moderately fluent French-English bilinguals were scanned while they

listened to stories in their first language (L1 = French) or in a second language (L2

= English) acquired at school after the age of seven. In all subjects, listening to L1

always activated a similar set of areas in the left temporal lobe, clustered along the

left superior temporal sulcus. Listening to L2, however, activated a highly variable

network of left and right temporal and frontal areas, sometimes restricted only to

right-hemispheric regions. These results support the hypothesis that first

language acquisition relies on a dedicated left-hemispheric cerebral network, while

late second language acquisition is not necessarily associated with a reproducible

biological substrate. The postulated contribution of the right hemisphere to L2

comprehension is found to hold only on average, individual subjects varying from

complete right lateralization to standard left lateralization for L2.

79. Deicken, R. F.; Zhou, L.; Schuff, N.; Weiner, M. W. Proton magnetic resonance

spectroscopy of the anterior cingulate region in schizophrenia. Schizophr-Res.

1997 Oct 17; 27(1): 65-71; ISSN: 0920-9964.

NETHERLANDS. The authors measured N-acetylaspartate (NAA, a putative

neuronal marker), choline and creatine in the anterior cingulate region of 26

schizophrenic patients and 16 control subjects using in vivo proton magnetic

resonance spectroscopic imaging (1H MRSI). Relative to the control group, the

patients with schizophrenia demonstrated significantly lower NAA in both the

right and left anterior cingulate regions. There was no association between NAA

and duration of illness or medication dosage. No group differences or lateralized

asymmetries in choline or creatine were noted. The NAA findings provide

support for either neuronal dysfunction or neuronal loss in the anterior cingulate

region in schizophrenia. The absence of choline signal elevation does not support

accelerated turnover of membrane phospholipids which might be expected if there

were ongoing neuronal atrophy or neuronal necrosis.. 0; 56-84-8; 57-00-1; 62-49-

7; 997-55-7.

80. Delazer, M.; Benke, T. Arithmetic facts without meaning. Cortex. 1997 Dec; 33(4):

697-710; ISSN: 0010-9452.

ITALY. The paper presents a single-case study of patient J.G. showing severe

calculation problems (and also agraphia, finger agnosia, right-left disorientation

and apraxia) after the surgery of a left parietal tumor. Although the patient

completely lost conceptual knowledge of arithmetic, she preserved part of

memorised fact knowledge (multiplications and some additions and subtractions).

The study indicates that arithmetic facts can be represented at a superficial level

without understanding of the operation performed. The study completes a valid

double dissociation between two types of knowledge involved in calculation

(memorised facts and conceptual knowledge).

81. Deng, C.; Rogers, L. J. Differential contributions of the two visual pathways to

functional lateralization in chicks. Behav-Brain-Res. 1997 Sep; 87(2): 173-82;

ISSN: 0166-4328.

NETHERLANDS. The contribution of the two visual pathways to lateralization

of visual behaviour in chicks was assessed using unilateral injections of 0.5

microliters of 100 mM monosodium glutamate into localized regions of the

forebrain. Chicks treated with glutamate in the left visual hyperstriatum made

more errors in a visual discrimination task (pebble-floor test) than did chicks

treated in the right visual hyperstriatum. Glutamate injection into the left visual

hyperstriatum also elevated attack and copulation scores, but this did not occur

following injection of the right visual hyperstriatum. The performance of chicks

treated in the right visual hyperstriatum did not differ from that of sham-operated

controls. Thus, only the left visual hyperstriatum is involved in the control of

these three visually guided behaviours. By contrast, glutamate injections of the

left ectostriatum affected only the attack behavior and not performance in the

pebble-floor test or copulation responses. Glutamate treatment of the right

ectostriatum had no affect on any of the behaviours tested and this was also the

case for glutamate treatment of both the left and right neostriata. Although

injecting glutamate in a larger volume that allows glutamate to spread over a wide

area of the left hemisphere is known to retard auditory habituation, localized

injection of glutamate in the areas chosen for this study had no effect on auditory

habituation. The results suggest that the tectofugal and thalamofugal pathways

have different roles in the lateralization of visual functions. The forebrain region

which receives input from the thalamofugal visual system has a lateralized role in

categorising pebbles as different from food grains, and also a role in controlling

attack and copulation responses. The forebrain region which receives input from

the tectofugal visual system is involved in the control of attack responses only..

56-86-0.

82. Desmond, J. E.; Gabrieli, J. D.; Wagner, A. D.; Ginier, B. L.; Glover, G. H. Lobular

patterns of cerebellar activation in verbal working-memory and finger-tapping

tasks as revealed by functional MRI. J-Neurosci. 1997 Dec 15; 17(24): 9675-85;

ISSN: 0270-6474.

UNITED-STATES. The lobular distributions of functional activation of the

cerebellum during verbal working-memory and finger movement tasks were

investigated using functional magnetic resonance imaging (fMRI). Relative to a

rest control, finger tapping of the right hand produced ipsilateral-increased

activation in HIV/HV [Roman numeral designations based on Larsell's ()

nomenclature] and HVI and weaker activation in HVIII that was stronger on the

ipsilateral side. For a working-memory task, subjects were asked to remember six

(high load) or one (low load) visually presented letters across a brief delay. To

assess the motoric aspects of rehearsal in the absence of working memory, we

asked the subjects to repeatedly read subvocally six or one letters at a rate that

approximated the internally generated rehearsal of working memory (motoric

rehearsal task). For both tasks, bilateral regions of the superior cerebellar

hemispheres (left superior HVIIA and right HVI) and portions of posterior vermis

(VI and superior VIIA) exhibited increased activation during high relative to low

load conditions. In contrast, the right inferior cerebellar hemisphere (HVIIB)

exhibited this load effect only during the working-memory task. We hypothesize

that HVI and superior HVIIA activation represents input from the articulatory

control system of working memory from the frontal lobes and that HVIIB

activation is derived from the phonological store in temporal and parietal regions.

From these inputs, the cerebellum could compute the discrepancy between actual

and intended phonological rehearsal and use this information to update a

feedforward command to the frontal lobes, thereby facilitating the phonological

loop.

83. Dolan, R. J.; Fletcher, P.; Morris, J.; Kapur, N.; Deakin, J. F.; Frith, C. D. Neural

activation during covert processing of positive emotional facial expressions.

Neuroimage. 1996 Dec; 4(3 Pt 1): 194-200; ISSN: 1053-8119.

UNITED-STATES. Lesion studies indicate distinct neural systems for

recognition of facial identity and emotion. Split-brain experiments also suggest

that emotional evaluation of a stimulus can occur without conscious identification.

The present study tested a hypothesis of a differential neural response,

independent of explicit conscious mediation, to emotional compared to

nonemotional faces. The experimental paradigm involved holding in mind an image

of a face across a 45-s delay while regional cerebral blood flow was measured

using positron emission tomography. Prior to the delay, a single face was

presented with an explicit instruction to match it to one of two faces,

photographed at different angles from the target face, presented at the end of the

delay. Repeated blood flow measures were obtained while subjects held happy or

neutral faces in mind or during a neutral control fixation condition without initial

face presentation. The representation of emotional faces over a delay period,

compared to either the nonemotional or the fixation condition, was associated

with significant activation in the left ventral prefrontal cortex, the left anterior

cingulate cortex, and the right fusiform gyrus. The findings support our

hypothesis of a differential neural response to facial emotion, independent of

conscious mediation, in regions implicated in the processing of faces and of

emotions.

84. Duyn, J. H.; Yang, Y.; Frank, J. A.; Mattay, V. S.; Hou, L. Functional magnetic

resonance neuroimaging data acquisition techniques. Neuroimage. 1996 Dec; 4(3

Pt 3): S76-83; ISSN: 1053-8119.

UNITED-STATES. Functional MRI studies of human brain require rapid data

acquisition techniques, to map dynamic changes with sufficient anatomical

coverage. In addition, task activation studies employing functional MRI require a

high scan sensitivity, in order to discriminate the small, activation-related signal

changes from background noise. An overview is given of current fast scan

methods, which are sensitized to detect susceptibility changes related to task-

induced changes in blood oxygenation. Sources of artifacts are discussed, as well

as their effect on image quality.

85. Edlinger, G.; Pfurtscheller, G.; van Burik, M.; Wach, P. Post-movement EEG

synchronization studied with different high resolution methods. Brain-Topogr.

1997 Dec; 10(2): 103-13; ISSN: 0896-0267.

UNITED-STATES. In this paper we present a study of spline surface Laplacian

(LP), linear estimation (LE) and analytical deblurring (AD) utilized to improve the

spatial resolution of single trial EEG data. AD is a method to reconstruct the

potential distribution on the cortical surface. The dependency of AD on the

electrode grid size as well as the sensitivity to uncorrelated noise and errors in the

volume conductor model are investigated in detail and compared with LP. Finally,

all methods (LP,LE and AD) are applied to single trial EEG data recorded in three

subjects during voluntary and self-paced extension and flexion movements of the

right index finger. In each subject postmovement beta oscillations were found in

specific frequency bands. Cortical dipolar source strengths were reconstructed by

LE and cortex potentials were estimated with AD. Both results are compared with

LP calculated from the scalp EEG. All methods, although having different

theoretical basis, yield similar results and reveal a maximal event-related

synchronization over the left sensorimotor area approximately 500-875 ms after

termination of the movement.

86. Eiselt, M.; Schendel, M.; Witte, H.; Dorschel, J.; Curzi Dascalova, L.; D'Allest, A.

M.; Zwiener, U. Quantitative analysis of discontinuous EEG in premature and

full-term newborns during quiet sleep. Electroencephalogr-Clin-Neurophysiol.

1997 Nov; 103(5): 528-34; ISSN: 0013-4694.

IRELAND. To assess the spatio-temporal structure of discontinuous EEG

tracing in mature and immature newborns, we analysed mean spectral power in

frequency bands between 0.8 and 16.8 Hz in 6 full-term newborns and 7

premature newborns < 32 weeks of conceptional age. The most striking results

showed a significantly higher mean spectral power for the first half of bursts than

for the second half recorded in > 2.8-14.8 Hz frequency bands. This pattern was

more pronounced in premature than in full-term newborns. No clear differences

were observed in comparisons between the first and the second half of the

interburst periods. In addition, as far as mid and high frequency band spectra were

considered, the mean spectral power of burst was, in both groups, higher in the

right as compared to the left occipital regions.

87. Elger, B.; Hornberger, W.; Schwarz, M.; Seega, J. MRI study on delayed ancrod

therapy of focal cerebral ischaemia in rats. Eur-J-Pharmacol. 1997 Oct 1; 336(1):

7-14; ISSN: 0014-2999.

NETHERLANDS. The therapeutic window for efficient post-treatment of focal

cerebral ischaemia with the fibrinogen lowering agent ancrod was studied by

magnetic resonance imaging (MRI) in spontaneously hypertensive rats (SHR).

Ancrod or vehicle solution (0.9% NaCl) were i.v. infused (0.12 IU/kg per min) via

implanted mini pumps starting 0.5, 1.5, 3 or 6 h after permanent proximal middle

cerebral artery occlusion and lasting until brain mapping by multislice T2-

weighted magnetic resonance imaging in vivo 24 h after middle cerebral artery

occlusion. Plasma fibrinogen concentrations were measured before middle cerebral

artery occlusion, before pump implantation and after magnetic resonance imaging.

Total brain lesion volumes as determined by magnetic resonance imaging 24 h after

middle cerebral artery occlusion were 131 +/- 36 (188 +/- 28)*, 151 +/- 39 (194

+/- 39)*, 147 +/- 44 (207 +/- 33)* and 209 +/- 60 (214 +/- 42) mm3 in rats with

0.5, 1.5, 3 and 6 h, respectively, delay of ancrod treatment (means +/- S.D., 8-11

animals/group, corresponding control groups in parentheses, *P < 0.05).

Continuous i.v. ancrod infusions reduced plasma fibrinogen levels significantly (P

< 0.05) in all ancrod-treated groups as compared to vehicle-treated controls until

the end of the experiments 24 h after middle cerebral artery occlusion. In

conclusion, significant cerebroprotection was achieved even when the onset of

ancrod therapy for lowering of the plasma fibrinogen level was delayed for up to 3

h. To the best of our knowledge no drug efficacy has been reported so far with a

therapeutic window of 3 h after permanent middle cerebral artery occlusion in

spontaneously hypertensive rats suggesting that ancrod may provide an efficient

therapy of acute human stroke.. EC 3.4.21.28; 0; 9001-32-5.

88. Epstein, J. N.; Conners, C. K.; Erhardt, D.; March, J. S.; Swanson, J. M.

Asymmetrical hemispheric control of visual-spatial attention in adults with

attention deficit hyperactivity disorder. Neuropsychology. 1997 Oct; 11(4): 467-

73; ISSN: 0894-4105.

UNITED-STATES. As neuropsychological mechanisms for attention have been

hypothesized to be located in the right hemisphere of the brain, several

investigators have begun to conceptualize attention deficit hyperactivity disorder

(ADHD)-related attentional deficits as involving right-hemispheric abnormalities.

The authors evaluated and compared adult patients diagnosed with ADHD with a

non-ADHD group of patients using a chronometric visual-spatial attention task

that is sensitive to hemispheric differences in efficiency of information processing.

Reaction times across different cuing conditions, cue-target delays, and visual

fields were assessed. When participants' attention was misdirected with cues in

the right visual field and attention had to be switched to a target on the left visual

field, there was a longer delay among ADHD adults than non-ADHD adults,

specifically when the interval between the cue and target was 800 ms as compared

with 100 ms. This specific pattern of dysfunction was interpreted as a difficulty

with maintaining attention possibly associated with anterior attention mechanisms

in the right hemisphere.

89. Ernst, M.; Cohen, R. M.; Liebenauer, L. L.; Jons, P. H.; Zametkin, A. J. Cerebral

glucose metabolism in adolescent girls with attention-deficit/hyperactivity

disorder. J-Am-Acad-Child-Adolesc-Psychiatry. 1997 Oct; 36(10): 1399-406;

ISSN: 0890-8567.

UNITED-STATES. OBJECTIVE: Low cerebral metabolic rates for glucose

(CMRglc) have been reported in a small sample of girls with attention-

deficit/hyperactivity disorder (ADHD). This study was an effort to replicate this

finding in a larger independent sample. METHOD: Using positron emission

tomography and [18F]fluorodeoxyglucose, CMRglc were compared between 10

girls with ADHD (14.10 +/- 1.91 years) and 11 normal girls (14.3 +/- 1.70 years).

RESULTS: Global CMRglc was similar between ADHD and control girls.

Lateralization of normalized CMRglc differed significantly between ADHD and

control girls in parietal and subcortical regions, with rCMRglc lower on the left

than on the right side in girls with ADHD, and conversely in control girls. The

sylvian area of the parietal region and the anterior putamen of the subcortical

region were the main contributors to this effect. Normalized rCMRglc of the

hippocampus was higher in ADHD than in control girls. Sexual maturation was

the only clinical characteristic that differed between present and previous

samples, and it correlated with global CMRglc. CONCLUSIONS: Although failing

to confirm abnormally low CMRglc in girls with ADHD, this study suggested

that (1) functional interactions between sex and brain development may contribute

to ADHD pathophysiology, and (2) sexual maturation should be controlled in

future CMRglc studies of adolescent girls.. 50-99-7.

90. Esser, K. H.; Condon, C. J.; Suga, N.; Kanwal, J. S. Syntax processing by auditory

cortical neurons in the FM-FM area of the mustached bat Pteronotus parnellii.

Proc-Natl-Acad-Sci-U-S-A. 1997 Dec 9; 94(25): 14019-24; ISSN: 0027-8424.

UNITED-STATES. Syntax denotes a rule system that allows one to predict the

sequencing of communication signals. Despite its significance for both human

speech processing and animal acoustic communication, the representation of

syntactic structure in the mammalian brain has not been studied

electrophysiologically at the single-unit level. In the search for a neuronal correlate

for syntax, we used playback of natural and temporally destructured complex

species-specific communication calls-so-called composites-while recording

extracellularly from neurons in a physiologically well defined area (the FM-FM

area) of the mustached bat's auditory cortex. Even though this area is known to be

involved in the processing of target distance information for echolocation, we

found that units in the FM-FM area were highly responsive to composites. The

finding that neuronal responses were strongly affected by manipulation in the

time domain of the natural composite structure lends support to the hypothesis

that syntax processing in mammals occurs at least at the level of the nonprimary

auditory cortex.

91. Fallgatter, A. J.; Roesler, M.; Sitzmann, L.; Heidrich, A.; Mueller, T. J.; Strik, W. K.

Loss of functional hemispheric asymmetry in Alzheimer's dementia assessed with

near-infrared spectroscopy. Brain-Res-Cogn-Brain-Res. 1997 Jul; 6(1): 67-72;

ISSN: 0926-6410.

NETHERLANDS. In a total of 10 patients with dementia of the Alzheimer-type

(DAT) and in 10 healthy controls near-infrared spectroscopy (NIRS), a new non-

invasive optical method, was used to measure the changes of concentrations of

oxy- (O2HB) and deoxyhemoglobin (HHB) in left and right hemispheric

prefrontal brain tissue areas during performance of the Verbal Fluency Test

(VFT). On a neuropsychological level, the healthy subjects performed better in

the VFT than patients with DAT. Statistical analysis of the relative

concentrations of O2HB and HHB measured with NIRS during performance of

the VFT revealed a significant interaction of the hemispheric effects with the

diagnosis. A possible interpretation of this finding is that a good performance in

the VFT relies on a predominantly left hemispheric activation observed in

controls, whereas a low number of correct responses is associated with a loss of

this asymmetric activation in patients with DAT. Although both, patients and

controls, performed better in the category version of the VFT, the metabolic

effects of this task were significantly less pronounced than in the letter version.

This indicates that different energy demands, according to the type of access to

the memory stores, may be interpreted as the result of a less energy-demanding

access to categorically stored information and adds further evidence to the view

that memory departments in humans are organized according to categorical

principles.

92. Favaretto, A. L.; Ballejo, G. O.; Albuquerque Araujo, W. I.; Gutkowska, J.; Antunes

Rodrigues, J.; McCann, S. M. Oxytocin releases atrial natriuretic peptide from rat

atria in vitro that exerts negative inotropic and chronotropic action. Peptides.

1997; 18(9): 1377-81; ISSN: 0196-9781.

UNITED-STATES. Our previous experiments suggested that natriuresis induced

by blood volume expansion, was brought about by oxytocin (OT)-stimulated

atrial natriuretic peptide (ANP) release from the right atrium. We hypothesized

that the ANP released might exert effects on the atrium itself and therefore carried

out in vitro experiments to test this hypothesis. Heart rate and isometric tension

were recorded from isolated rat atria mounted in an organ bath. Oxytocin exerted a

dose-related, negative chrono- and inotropic effect with a minimal effective

concentration (MEC) of 3 microM, 10-fold higher than required for ANP to exert

comparable effects. The effects of OT were not blocked by atropine suggesting

that they were not mediated via release of acetylcholine. Eight-bromoguanosine 3'-

5'-cyclic monophosphate (cGMP) had similar effects to those of OT and ANP,

suggesting that the effects of ANP were mediated by cGMP. When isolated

ventricles, left or right atria, were incubated in vitro, OT had a dose-related effect

to stimulate the release of ANP into the medium only from right atria with a MEC

of 0.1 microM. A specific OT antagonist, F792 (1 microM), inhibited basal

release of ANP and blocked the stimulatory action of OT on ANP release. The

results support the hypothesis that OT, acting on its putative receptors in the

right atrium, stimulates the release of ANP which then exerts a negative chrono-

and inotropic effect via activation of guanylyl cyclase and release of cGMP. The

ability of the oxytocin antagonist to reduce basal release of ANP from atria

incubated in vitro supports the hypothesis that these effects could be

physiologically significant. We hypothesize that blood volume expansion via

baroreceptor input to the brain causes the release of OT which circulates to the

heart and stimulates the release of ANP from the right atrium. This ANP then has

a negative ino- and chronotropic effect in the atrium and possibly a negative

inotropic effect in the right ventricle, left atrium and left ventricle, to produce an

acute reduction in cardiac output that, coupled with its peripheral vasodilating

actions, causes a rapid reduction in effective circulating blood volume. The ANP

released would also act on the kidneys to cause natriuresis and ANP acts within

the brain to inhibit water and salt intake leading to a gradual recovery of circulating

blood volume to normal.. 50-56-6; 85637-73-6.

93. Fernandez, G.; Weyerts, H.; Schrader Bolsche, M.; Tendolkar, I.; Smid, H. G.;

Tempelmann, C.; Hinrichs, H.; Scheich, H.; Elger, C. E.; Mangun, G. R.; Heinze,

H. J. Successful verbal encoding into episodic memory engages the posterior

hippocampus: a parametrically analyzed functional magnetic resonance imaging

study. J-Neurosci. 1998 Mar 1; 18(5): 1841-7; ISSN: 0270-6474.

UNITED-STATES. The medial temporal lobe (MTL) is essential for episodic

memory encoding, as evidenced by memory deficits in patients with MTL

damage. However, previous functional neuroimaging studies have either failed to

show MTL activation during encoding or they did not differentiate between two

MTL related processes: novelty assessment and episodic memory encoding.

Furthermore, there is evidence that the MTL can be subdivided into

subcomponents serving different memory processes, but the extent of this

functional subdivision remains unknown. The aim of the present functional

magnetic resonance imaging (fMRI) study was to investigate the role of the MTL

in episodic encoding and to determine whether this function might be restricted to

anatomical subdivisions of the MTL. Thirteen healthy volunteers performed a

word list learning paradigm with free recall after distraction. Functional images

acquired during encoding were analyzed separately for each participant by a

voxel-wise correlation (Kendall's tau) between the time series of the T2*-signal

intensity and the number of subsequently recalled words encoded during each

particular scan. Of the 13 participants, 11 showed voxel clusters with statistically

significant, positive correlations in the posterior part of the hippocampus. Across

participants, an ANOVA on the number of voxels with significant, positive

correlations within individually defined volumes of interest confirmed a

statistically significant difference in activation for anterior versus posterior regions

of the hippocampus. However, no differences between left and right hippocampal

activation were revealed. Thus, these findings demonstrate that successful

encoding into episodic memory engages neural circuits in the posterior part of the

hippocampus.

94. Fink, G. R.; Dolan, R. J.; Halligan, P. W.; Marshall, J. C.; Frith, C. D. Space-based

and object-based visual attention: shared and specific neural domains. Brain. 1997

Nov; 120( Pt 11): 2013-28; ISSN: 0006-8950.

ENGLAND. Visual attention can be primarily allocated to either where an object

is in space (with little emphasis on the structure of the object itself) or to the

structure of the object (with little emphasis on where in space the object is

located). Using PET measures of regional cerebral blood flow (rCBF) to index

neural activity, we investigated the shared and specific functional anatomy

underlying both of these types of visual attention in a controlled non-cueing non-

blocked paradigm that involved identical stimuli across the conditions of interest.

The interaction of eye movements with these attentional systems was studied by

introducing fixation or free vision as an additional factor. Relative to the control

condition, object-based and space-based attention showed significant activations

of the left and right medial superior parietal cortex and the left lateral inferior

parietal cortex, the left prefrontal cortex and the cerebellar vermis. Significant

differential activations were observed during object-based attention in the left

striate and prestriate cortex. Space-based attention activated the right prefrontal

cortex and the right inferior temporal-occipital cortex. Differential neural activity

due to free vision or fixation was observed in occipital areas only. Significant

interactions of free vision/fixation on activations due to object-based and space-

based attention were observed in the right medial superior parietal cortex and left

lateral inferior parietal cortex, respectively. The study provides direct evidence for

the importance of the parietal cortex in the control of object-based and space-

based visual attention. The results show that object-based and space-based

attention share common neural mechanisms in the parietal lobes, in addition to

task specific mechanisms in early visual processing areas of temporal and occipital

cortices.

95. Fink, G. R.; Halligan, P. W.; Marshall, J. C.; Frith, C. D.; Frackowiak, R. S.; Dolan,

R. J. Neural mechanisms involved in the processing of global and local aspects of

hierarchically organized visual stimuli. Brain. 1997 Oct; 120( Pt 10): 1779-91;

ISSN: 0006-8950.

ENGLAND. We investigated the functional anatomy involved in sustaining or

switching visual attention between different perceptual levels, using functional

imaging measures of neural activity. Two experiments were carried out using

hierarchically organized letters (i.e. large letters made out of small letters). In a

divided-attention task, subjects were required to switch attention between local

and global levels. The number of successive stimuli for which subjects had to

sustain attention to either the global or local level co-varied significantly with

temporal-parietal activations bilaterally. Other activations were also observed in

the right orbitofrontal cortex, the right dorsolateral prefrontal cortex, and the right

middle temporal gyrus. The number of switches between levels co-varied

significantly with activations in the left supplementary motor area and the left

medial parietal cortex. In the directed-attention task, subjects were required to

attend to either the global or local level of the stimuli throughout all trials;

attention to the global aspect resulted in significant activation of the right lingual

gyrus while attention to the local aspect significantly activated the left inferior

occipital cortex. We suggest that left hemisphere activations with increasing

numbers of switches between perceptual levels reflect increased demands on an

executive attentional system, while sustained attention to either level activates a

predominantly right hemispheric network involving temporal-parietal and

dorsolateral prefrontal regions. Overall, the results provide evidence for relative

hemispheric specialization for global and local processing in accordance with

previous neuropsychological studies. In addition, the findings demonstrate that

early visual processing mechanisms in the prestriate cortex are influenced by an

attentional system in temporal-parietal areas.

96. Fransson, P.; Kruger, G.; Merboldt, K. D.; Frahm, J. A comparative FLASH and EPI

study of repetitive and sustained visual activation. NMR-Biomed. 1997 Jun;

10(4-5): 204-7; ISSN: 0952-3480.

ENGLAND. Functional responses to either brief repetitive or sustained

activation of the human visual cortex (movie presentation) were monitored using

both fast low angle shot and echo planar imaging sequences. To allow for proper

comparisons, native image contrasts were equally sensitized to changes in cerebral

blood oxygenation with other experimental conditions matched as much as

possible. Putative influences of receiver bandwidth and absolute voxel size were

specifically addressed. In all cases resulting correlation maps and regional signal

intensity time courses showed excellent spatial and temporal congruence,

respectively. In particular, for a 6 min protocol of sustained activation, both

FLASH and EPI yielded an initial signal increase (oxygenation overshoot), a

subsequent signal decrease during ongoing stimulation, and a marked signal drop

(oxygenation undershoot) after the end of stimulation. These findings exclude

technical differences between FLASH and EPI as the source of previous

contradictory observations more likely to be explained by differences in stimulus

design.

97. Fritsch, M.; Manwaring, K. H. Endoscopic treatment of brain abscess in children.

Minim-Invasive-Neurosurg. 1997 Sep; 40(3): 103-6; ISSN: 0946-7211.

GERMANY. Three children with intracerebral abscesses were treated

endoscopically. Two of the treated abscesses were located in the left temporal

lobe and one in the right parietal lobe. The presenting symptoms included

headaches, seizures, hemiparesis and signs of infection. Burr hole craniotomy,

insertion of a peelaway sheath, obtaining of a specimen, introduction of

endoscope, and complete irrigation under view was performed. After this a

draining catheter was positioned in the abscess. All three abscesses grew multiple

organisms. The patients received longstanding intravenous treatment with

antibiotics. The follow-up period in this group ranges between 5 and 32 months.

The initial neurological deficits were relieved in all three patients. The follow-up

MRI studies revealed minor residual changes without evidence of significant

sequelae. Neuroendoscopic treatment of brain abscesses has additional advantages

compared to stereotactic aspiration or more complete drainage and lavage.

98. Fukushima, K. Corticovestibular interactions: anatomy, electrophysiology, and

functional considerations. Exp-Brain-Res. 1997 Oct; 117(1): 1-16; ISSN: 0014-

4819.

GERMANY. This review summarizes anatomical and electrophysiological

observations related to corticovestibular interactions as a step toward

understanding their possible functions. Vestibular information is represented in at

least three distinct regions of the cerebral cortex in cats and monkeys: the parietal

and somatosensory cortex and the parietoinsular vestibular cortex. In addition,

vestibular-related signals are found in more extensive regions, including the motor

and premotor regions and frontal eye fields. Most of these regions also project

directly to the vestibular nuclei. In monkeys, at least six cortical regions have been

identified, including the motor, somatosensory, parietal and temporal areas. Most

of these regions receive vestibular projections via the thalamus. Most neurons in

those cortical areas respond to head velocity and receive converging vestibular,

visual and somatosensory input. Electrical stimulation of some of these cortical

areas in anesthetized cats influences the activity of many vestibular nuclear

neurons including those projecting to the spinal cord. Lesions of the parietal

vestibular regions impair the vestibulo-ocular reflex (VOR) and visual suppression

of the VOR as well as vestibular-related cognitive functions such as spatial

perception and memory in human subjects. Diffuse cortical damage also results in

similar impairment of the VOR and suppression of the VOR and possibly the

vestibulo-collic reflex. Such impairments after cortical lesions may well be due in

part to interruption of cortico-vestibular connections. Future studies in alert

animals should focus on the role of different cortical regions projecting to the

vestibular nuclei, specifically on how each affects the processing of vestibular

signals that mediate vestibulo-motor reflexes and that are used for vestibular

related cognitive processes.

99. Fushiki, H.; Barmack, N. H. Topography and reciprocal activity of cerebellar Purkinje

cells in the uvula-nodulus modulated by vestibular stimulation. J-Neurophysiol.

1997 Dec; 78(6): 3083-94; ISSN: 0022-3077.

UNITED-STATES. In the rabbit uvula-nodulus, vestibular and optokinetic

information is mapped onto parasagittal zones by climbing fibers. These zones are

related functionally to different pairs of vertical semicircular canals, otolithic

inputs and horizontal optokinetic inputs. Vestibular stimulation restricted to one

of these zones modulates climbing fiber responses (CFRs). Within each of these

zones, simple spikes (SSs) are modulated reciprocally with CFRs. In rabbits

anesthetized with chloralose-urethan, we have used vestibular and optokinetic

stimulation to evoke CFRs within a parasagittal zone while recording from

Purkinje cells in adjacent zones. We have examined whether the CFRs evoked by

vestibular stimulation in one zone influence the SSs of an adjacent zone. CFRs and

SSs were recorded during roll vestibular stimulation. The orientation of the head of

the rabbit with respect to the axis of rotation was varied systematically so that a

climbing fiber null plane could be determined. This null plane was the orientation

of the head about the vertical axis at which no modulation of the CFR was

observed during rotation about the longitudinal axis of the vestibular rate table. In

the left uvula-nodulus, a medial sagittal strip extending through all the folia

contained Purkinje cells with CFRs that had optimal planes of stimulation

coplanar with the left posterior-right anterior semicircular canals (LPC-RAC).

Lateral to this strip was a strip of Purkinje cells with CFRs that were

characterized by optimal planes corresponding to stimulation of the left anterior-

right posterior semicircular canals (LAC-RPC). SSs in Purkinje cells were

modulated out of phase with CFRs from the same Purkinje cell. The depth of

modulation of both CFRs and SSs was reduced during rotation in the climbing

fiber "null plane". The depth of modulation of SSs was greatest when recorded

from Purkinje cells located at the center of semicircular canal-related strip. We

observed that 1) all folia of the uvula-nodulus receive vestibular climbing fiber

inputs; 2) these climbing fiber inputs convey information from the vertical

semicircular canals and otoliths but not the horizontal semicircular canals; 3)

CFRs evoked in a particular sagittal zone do not influence SSs in adjacent zones;

4) modulation of a CFRs in a particular Purkinje cell can occur without

modulation of SSs in the same Purkinje cell, although modulation of SSs was not

observed in the absence of CFR modulation; and 5) modulation of SSs sometimes

preceded that of CFRs in the same cell, implying that interneuronal pathways

may contribute to SS modulation. Climbing fiber-driven Golgi cells, the inhibitory

axon terminals of which end on granule cell dendrites in the classic glomerular

synapse, may provide this interneuronal mechanism.

100. Gabrieli, J. D.; Poldrack, R. A.; Desmond, J. E. The role of left prefrontal cortex in

language and memory. Proc-Natl-Acad-Sci-U-S-A. 1998 Feb 3; 95(3): 906-13;

ISSN: 0027-8424.

UNITED-STATES. This article reviews attempts to characterize the mental

operations mediated by left inferior prefrontal cortex, especially the anterior and

inferior portion of the gyrus, with the functional neuroimaging techniques of

positron emission tomography and functional magnetic resonance imaging.

Activations in this region occur during semantic, relative to nonsemantic, tasks for

the generation of words to semantic cues or the classification of words or pictures

into semantic categories. This activation appears in the right prefrontal cortex of

people known to be atypically right-hemisphere dominant for language. In this

region, activations are associated with meaningful encoding that leads to superior

explicit memory for stimuli and deactivations with implicit semantic memory

(repetition priming) for words and pictures. New findings are reported showing

that patients with global amnesia show deactivations in the same region associated

with repetition priming, that activation in this region reflects selection of a

response from among numerous relative to few alternatives, and that activations in

a portion of this region are associated specifically with semantic relative to

phonological processing. It is hypothesized that activations in left inferior

prefrontal cortex reflect a domain-specific semantic working memory capacity

that is invoked more for semantic than nonsemantic analyses regardless of

stimulus modality, more for initial than for repeated semantic analysis of a word

or picture, more when a response must be selected from among many than few

legitimate alternatives, and that yields superior later explicit memory for

experiences.

101. Gainotti, G.; Azzoni, A.; Gasparini, F.; Marra, C.; Razzano, C. Relation of lesion

location to verbal and nonverbal mood measures in stroke patients. Stroke. 1997

Nov; 28(11): 2145-9; ISSN: 0039-2499.

UNITED-STATES. BACKGROUND AND PURPOSE: The aim of the present

study was to evaluate the relation between poststroke depression and lesion

location, avoiding previous methodological shortcomings. In particular, we

intended to determine whether patients with left frontal lesions showed the

highest depression scores. METHODS: Patients in the study, categorized on the

basis of lesion location, included 149 stroke patients with lesions located in the

anterior, central, or posterior regions of the right or left hemisphere. Verbal and

nonverbal mood measures as well as the Hamilton Depression Scale Overall Score

were the dependent measures of our investigation. Furthermore, the number of

patients who could not be assessed or could be evaluated only with the nonverbal

mood measure due to the presence of severe language disorders was recorded.

RESULTS: No significant relation was observed between depressed mood and

lesion location. Approximately one quarter of the left brain-damaged patients

were partially or totally excluded from the study because of severe language

disorders. CONCLUSIONS: Our data appeared to show that when

methodological pitfalls and selection bias are carefully controlled, left frontal

lesions are not a major determinant of poststroke depression.

102. Gannon, P. J.; Holloway, R. L.; Broadfield, D. C.; Braun, A. R. Asymmetry of

chimpanzee planum temporale: humanlike pattern of Wernicke's brain language

area homolog. Science. 1998 Jan 9; 279(5348): 220-2; ISSN: 0036-8075.

UNITED-STATES. The anatomic pattern and left hemisphere size predominance

of the planum temporale, a language area of the human brain, are also present in

chimpanzees (Pan troglodytes). The left planum temporale was significantly

larger in 94 percent (17 of 18) of chimpanzee brains examined. It is widely

accepted that the planum temporale is a key component of Wernicke's receptive

language area, which is also implicated in human communication-related disorders

such as schizophrenia and in normal variations such as musical talent. However,

anatomic hemispheric asymmetry of this cerebrocortical site is clearly not unique

to humans, as is currently thought. The evolutionary origin of human language

may have been founded on this basal anatomic substrate, which was already

lateralized to the left hemisphere in the common ancestor of chimpanzees and

humans 8 million years ago.

103. Gaschler Markefski, B.; Baumgart, F.; Tempelmann, C.; Schindler, F.; Stiller, D.;

Heinze, H. J.; Scheich, H. Statistical methods in functional magnetic resonance

imaging with respect to nonstationary time-series: auditory cortex activity. Magn-

Reson-Med. 1997 Nov; 38(5): 811-20; ISSN: 0740-3194.

UNITED-STATES. In awake animal and human auditory cortices, it is a common

experience with electrophysiological and suitable imaging methods for responses

to steady stimulation to be strongly state-dependent and to exhibit

nonstationarities, even over short periods of observation. If such nonstationary

behavior is also reflected by hemodynamic responses in the human auditory

cortex, conventional methods of analysis of fMRI data, although applicable for

instance to largely stationary responses in visual and other cortices, may be

misleading in attempts to parcellate auditory cortex into fields and to demonstrate

functional maps. Time-Windows, described in this article as a convenient tool for

the detection and analysis of time-variant brain activities, solves some of these

problems. Time-Windows demonstrates that activity is evoked reliably in three

separate territories of human auditory cortex, parts of which may show

nonstationary behavior, depending on the auditory stimuli and tasks.

104. Gati, I.; Papp, L.; Polgar, T. Infrared imaging of human brain sections. A new

biomedical application of the thermocamera. APMIS. 1997 Oct; 105(10): 801-5;

ISSN: 0903-4641.

DENMARK. Human brains, removed at routine autopsy, were subjected to

neuropathological investigation. The usual gross morphological investigation of

the brains was extended to include the detection of their infrared emissions.

Fundamental structures, such as the grey and the white matter, were separated on

the infrared images. Furthermore, pathological processes, such as ischaemic

damage, haemorrhage, and sclerotic plaques, hardly seen on the normal

photographs, gave a strong signal on the infrared pictures. These pilot

experiments demonstrated that infrared detection is a reproducible method in this

type of biomedical application, and potentially a very useful tool in macroscopic

pathology.. 50-00-0.

105. Gauger, L. M.; Lombardino, L. J.; Leonard, C. M. Brain morphology in children with

specific language impairment. J-Speech-Lang-Hear-Res. 1997 Dec; 40(6): 1272-

84; ISSN: 1092-4388.

UNITED-STATES. The planum temporale and pars triangularis have been found

to be larger in the left hemisphere than the right in individuals with normal

language skills. Brain morphology studies of individuals with developmental

language disorders report reversed asymmetry or symmetry of the planum,

although the bulk of this research has been completed on adults with dyslexia.

Pars triangularis has not been studied in the developmental language impaired

population. In this study, magnetic resonance imaging (MRI) was used for

quantitative comparisons of the planum temporale (Wernicke's area) and pars

triangularis (Broca's area) in children with specific language impairment (SLI) and

children with normal language skills. The subjects were 11 children with SLI and

19 age- and sex-matched controls between 5.6 and 13.0 years old. Each subject

received a neurolinguistic battery of tests and a high resolution volumetric MRI

scan. Major results were that (a) pars triangularis was significantly smaller in the

left hemisphere of children with SLI, and (b) children with SLI were more likely to

have rightward asymmetry of language structures. Furthermore, anomalous

morphology in these language areas correlated with depressed language ability.

These findings support the hypothesis that language impairment is a consequence

of an underlying neurobiological defect in areas of the brain known to subserve

language.

106. Gemba, H.; Miki, N.; Sasaki, K. Cortical field potentials preceding vocalization in

monkeys. Acta-Otolaryngol-Suppl-Stockh. 1997; 532: 96-8; ISSN: 0365-5237.

NORWAY. Field potentials before vocalization were studied with electrodes

chronically implanted on the surface and at a 2.0-3.0 mm depth in various cortical

areas in three monkeys. Surface-negative, depth-positive (s-N, d-P) slow

potentials prior to vocalization were recorded in the premotor (including the

Broca's homolog), motor and somatosensory cortices, and the supplementary

motor area (SMA). Such premovement potentials were recorded also in the

cingulate and prefrontal cortices when a monkey uttered a sound with intense

motivation for reward. Cerebellar hemispherectomy on the right side eliminated

the s-N, d-P premovement potentials in the motor cortex and in the posterior

bank of inferior limb of the arcuate sulcus (homolog of Broca's area) in the left

hemisphere. After the operation, the tone came to have less components of

different frequencies, and its duration varied much more than before. These facts

suggest that the neocortical area homologous to the human speech area takes part

in the generation and control of monkey vocalization together with the cerebellum

possibly through cerebro-cerebellar interactions. This is against ideas so far

proposed on nonhuman primate vocalization, i.e., it is generally considered that

animal vocalization differs fundamentally from human speech.

107. Ghatan, P. H.; Hsieh, J. C.; Petersson, K. M.; Stone Elander, S.; Ingvar, M.

Coexistence of attention-based facilitation and inhibition in the human cortex.

Neuroimage. 1998 Jan; 7(1): 23-9; ISSN: 1053-8119.

UNITED-STATES. A key function of attention is to select an appropriate

subset of available information by facilitation of attended processes and/or

inhibition of irrelevant processing. Functional imaging studies, using positron

emission tomography, have during different experimental tasks revealed decreased

neuronal activity in areas that process input from unattended sensory modalities.

It has been hypothesized that these decreases reflect a selective inhibitory

modulation of nonrelevant cortical processing. In this study we addressed this

question using a continuous arithmetical task with and without concomitant

disturbing auditory input (task-irrelevant speech). During the arithmetical task,

irrelevant speech did not affect task-performance but yielded decreased activity in

the auditory and midcingulate cortices and increased activity in the left posterior

parietal cortex. This pattern of modulation is consistent with a top down

inhibitory modulation of a nonattended input to the auditory cortex and a

coexisting, attention-based facilitation of task-relevant processing in higher order

cortices. These findings suggest that task-related decreases in cortical activity may

be of functional importance in the understanding of both attentional mechanisms

and task-related information processing.

108. Giedd, J. N.; Castellanos, F. X.; Rajapakse, J. C.; Vaituzis, A. C.; Rapoport, J. L.

Sexual dimorphism of the developing human brain. Prog-Neuropsychopharmacol-

Biol-Psychiatry. 1997 Nov; 21(8): 1185-201; ISSN: 0278-5846.

ENGLAND. 1. Sexual dimorphism of human brain anatomy has not been well-

studied between 4 and 18 years of age, a time of emerging sex differences in

behavior and the sexually specific hormonal changes of adrenarche (the

predominantly androgenic augmentation of adrenal cortex function occurring at

approximately age 8) and puberty. 2. To assess sex differences in brain structures

during this developmental period volumes of the cerebrum, lateral ventricles,

caudate, putamen, globus pallidus temporal lobe, amygdala, and hippocampus,

and midsagittal area measurements of the corpus callosum were quantified from

brain magnetic resonance images of 121 healthy children and adolescent and

examined in relation to age and sex. 3. Males had a 9% larger cerebral volume.

When adjusted for cerebral volume by ANCOVA only the basal ganglia

demonstrated sex differences in mean volume with the caudate being relatively

larger in females and the globus pallidus being relatively larger in males. The lateral

ventricles demonstrated a prominent sex difference in brain maturation with

robust increases in size in males only. A piecewise-linear model revealed a

significant change in the linear regression slope of lateral ventricular volume in

males after age 11 that was not shared by females at that or other ages. 4.

Amygdala and hippocampal volume increased for both sexes but with the

amygdala increasing significantly more in males than females and hippocampal

volume increasing more in females. 5. These sexually dimorphic patterns of brain

development may be related to the observed sex differences in age of onset,

prevalence, and symptomatology seen in nearly all neuropsychiatric disorders of

childhood.

109. Glass, I.; Sazbon, L.; Groswasser, Z. Mapping "cognitive" event-related potentials in

prolonged postcoma unawareness state. Clin-Electroencephalogr. 1998 Jan; 29(1):

19-30; ISSN: 0009-9155.

UNITED-STATES. "Cognitive" auditory event-related potentials (ERPs) were

mapped to examine the putative conscious responsiveness of eight patients in a

postcoma unawareness (PCU) state and of eight matched normal controls. A

"passive P3" paradigm was used to evaluate waves N2, P3, and Slow Waves of

the ERPs. Results showed that the signal/noise ratio of the patients' waveshapes

was poorer than that of the controls. Yet, on the whole, no between-group

significant differences were noted for most of the averaged characteristics of the

waves. In general, in the patients, the left hemisphere was dominated by negative

potentials relative to the right one, whereas in the controls, the opposite

asymmetry was apparent. Thirty-eight percent of the patients had passive N2

and P3 waves, and 67% of the responders regained consciousness (versus none of

the non-responders). These findings suggest that the presence of intact "cognitive"

waves is compatible with a higher probability for improvement, although

nondetection of certain waves at the postcoma unawareness state does not

necessarily indicate the worst prognosis.

110. Glass, M.; Dragunow, M.; Faull, R. L. Cannabinoid receptors in the human brain: a

detailed anatomical and quantitative autoradiographic study in the fetal, neonatal

and adult human brain. Neuroscience. 1997 Mar; 77(2): 299-318; ISSN: 0306-

4522.

UNITED-STATES. The anatomical distribution and density of cannabinoid

receptors in the human brain was studied in one fetal (33 weeks gestation), two

neonatal (aged three to six months) and eight adult (aged 21-81 years) human cases

using quantitative receptor autoradiography following in vitro labelling of sections

with the synthetic cannabinoid agonist [3H]CP55,940. Cannabinoid receptors

were distributed in a heterogeneous fashion throughout the adult human brain and

spinal cord. The allocortex contained very high concentrations of cannabinoid

receptor binding sites in the dentate gyrus, Ammons's horn and subiculum of the

hippocampal formation; high concentrations of receptors were also present in the

entorhinal cortex and amygdaloid complex. Cannabinoid receptor binding sites

were also present throughout all regions of the neocortex, where they showed a

marked variation in density between the primary, secondary and associational

cortical regions: the greatest densities of receptors were present in the

associational cortical regions of the frontal and limbic lobes, with moderate

densities in the secondary sensory and motor cortical regions, and with the lowest

densities of receptors in the primary sensory and motor cortical regions.

Relatively high concentrations of cannabinoid receptors were consistently seen in

cortical regions of the left (dominant) hemisphere, known to be associated with

verbal language functions. In all of the cortical regions, the pattern and density of

receptor labelling followed the neocortical laminar organization, with the greatest

density of receptors localized in two discrete bands--a clearly delineated narrow

superficial band which coincided with lamina I and a deeper broader, conspicuous

band of labelling which corresponded to laminae V and VI. Labelling in the

intervening cortical laminae (II-IV) showed lower densities, with a well delineated

narrow band of label in the middle of laminae IV in the associational cortical

regions. The thalamus showed a distinctive heterogeneous distribution of

cannabinoid receptors, with the highest concentration of receptors localized in the

mediodorsal nucleus, anterior nuclear complex, and in the midline and intralaminar

complex of nuclei, i.e. in thalamic nuclei which have connectional affiliations with

the associational cortical areas. The basal ganglia showed a distinctive

heterogeneous pattern of receptor binding, with the very highest concentrations in

the globus pallidus internus, moderate concentrations in the globus pallidus

externus and ventral pallidum, and moderately low levels of binding throughout

the striatal complex. In the midbrain, some of the highest levels of cannabinoid

receptor binding sites in the human brain were present in the substantia nigra pars

reticulata, with very low levels of labelling in all other midbrain areas. The highest

densities of cannabinoid receptor binding in the hindbrain were localized in the

molecular layer of the cerebellar cortex and the dorsal motor nucleus of the vagus,

with moderate densities of receptors in the nucleus of the solitary tract. The

spinal cord showed very low levels of receptor binding. Studies on the

distribution of cannabinoid receptors in the fetal and neonatal human brain

showed similar patterns of receptor distribution to that observed in the adult

human brain, except that the density of receptor binding was generally markedly

higher, especially in the basal ganglia and substantia nigra. The pattern of

cannabinoid receptor labelling in the striatum showed a striking patchy pattern of

organization which was especially conspicuous in the fetal brain. These results

show that cannabinoid receptor binding sites in the human brain are localized

mainly in: forebrain areas associated with higher cognitive functions; forebrain,

midbrain and hindbrain areas associated with the control of movement; and in

hindbrain areas associated with the control of motor and sensory functions of the

autonomic nervous system. (AB. 0; 0; 0; 0.

111. Glass, M.; Dragunow, M.; Faull, R. L. Cannabinoid receptors in the human brain: a

detailed anatomical and quantitative autoradiographic study in the fetal, neonatal

and adult human brain. Neuroscience. 1997 Mar; 77(2): 299-318; ISSN: 0306-

4522.

UNITED-STATES. The anatomical distribution and density of cannabinoid

receptors in the human brain was studied in one fetal (33 weeks gestation), two

neonatal (aged three to six months) and eight adult (aged 21-81 years) human cases

using quantitative receptor autoradiography following in vitro labelling of sections

with the synthetic cannabinoid agonist [3H]CP55,940. Cannabinoid receptors

were distributed in a heterogeneous fashion throughout the adult human brain and

spinal cord. The allocortex contained very high concentrations of cannabinoid

receptor binding sites in the dentate gyrus, Ammons's horn and subiculum of the

hippocampal formation; high concentrations of receptors were also present in the

entorhinal cortex and amygdaloid complex. Cannabinoid receptor binding sites

were also present throughout all regions of the neocortex, where they showed a

marked variation in density between the primary, secondary and associational

cortical regions: the greatest densities of receptors were present in the

associational cortical regions of the frontal and limbic lobes, with moderate

densities in the secondary sensory and motor cortical regions, and with the lowest

densities of receptors in the primary sensory and motor cortical regions.

Relatively high concentrations of cannabinoid receptors were consistently seen in

cortical regions of the left (dominant) hemisphere, known to be associated with

verbal language functions. In all of the cortical regions, the pattern and density of

receptor labelling followed the neocortical laminar organization, with the greatest

density of receptors localized in two discrete bands--a clearly delineated narrow

superficial band which coincided with lamina I and a deeper broader, conspicuous

band of labelling which corresponded to laminae V and VI. Labelling in the

intervening cortical laminae (II-IV) showed lower densities, with a well delineated

narrow band of label in the middle of laminae IV in the associational cortical

regions. The thalamus showed a distinctive heterogeneous distribution of

cannabinoid receptors, with the highest concentration of receptors localized in the

mediodorsal nucleus, anterior nuclear complex, and in the midline and intralaminar

complex of nuclei, i.e. in thalamic nuclei which have connectional affiliations with

the associational cortical areas. The basal ganglia showed a distinctive

heterogeneous pattern of receptor binding, with the very highest concentrations in

the globus pallidus internus, moderate concentrations in the globus pallidus

externus and ventral pallidum, and moderately low levels of binding throughout

the striatal complex. In the midbrain, some of the highest levels of cannabinoid

receptor binding sites in the human brain were present in the substantia nigra pars

reticulata, with very low levels of labelling in all other midbrain areas. The highest

densities of cannabinoid receptor binding in the hindbrain were localized in the

molecular layer of the cerebellar cortex and the dorsal motor nucleus of the vagus,

with moderate densities of receptors in the nucleus of the solitary tract. The

spinal cord showed very low levels of receptor binding. Studies on the

distribution of cannabinoid receptors in the fetal and neonatal human brain

showed similar patterns of receptor distribution to that observed in the adult

human brain, except that the density of receptor binding was generally markedly

higher, especially in the basal ganglia and substantia nigra. The pattern of

cannabinoid receptor labelling in the striatum showed a striking patchy pattern of

organization which was especially conspicuous in the fetal brain. These results

show that cannabinoid receptor binding sites in the human brain are localized

mainly in: forebrain areas associated with higher cognitive functions; forebrain,

midbrain and hindbrain areas associated with the control of movement; and in

hindbrain areas associated with the control of motor and sensory functions of the

autonomic nervous system. (AB. 0; 0; 0; 0.

112. Gonen, O.; Murdoch, J. B.; Stoyanova, R.; Goelman, G. 3D multivoxel proton

spectroscopy of human brain using a hybrid of 8th-order Hadamard encoding with

2D chemical shift imaging. Magn-Reson-Med. 1998 Jan; 39(1): 34-40; ISSN:

0740-3194.

UNITED-STATES. Multivoxel 3D localized proton spectroscopy using a hybrid

of 1D 8th-order transverse Hadamard spectroscopic imaging (HSI) with 2D

chemical shift imaging (CSI) is demonstrated in human brain. The spatially

selective HSI pulse incorporates naturally into the PRESS sequence (TE = 135

ms), which then both excites an 8 x 8 x 6 cm parallelepiped volume of interest

(VOI) and subdivides it into eight slices. The planes of these slices are further

partitioned into 16 x 16 voxel arrays using 2D CSI to yield 8 x 8 x 8 voxels within

the VOI. Simultaneous 3D coverage yields good voxel signal-to-noise (8, 12, and

22 for choline, creatine, and N-acetylaspartate, respectively) from these 0.75-ml

voxels, in approximately 45 min. The high spatial isolation allows localization to

within less than 1 cm from the skull without fat contamination.. 0.

113. Goscinski, I.; Kwiatkowski, S.; Polak, J.; Orlowiejska, M.; Partyk, A. The Kluver-

Bucy syndrome. J-Neurosurg-Sci. 1997 Sep; 41(3): 269-72; ISSN: 0390-5616.

ITALY. Evolution of psychological disorders following head injury including

memory disorders and other cognitive ones are common. The best known are

psychiatric disturbances of various kind after lesions of frontal lobes. Cognitive,

behavioural and emotional disorders are not usually seen in patients with bilateral

temporal lesions. In our Department of Neurotraumatology we observed 4

patients with post-traumatic lesions localized bitemporally. They developed

Kluver-Bucy syndrome--rarity in human pathology--with combination of three or

more the following syndromes: increased oral activity, hypersexuality,

hypermetamorphosis, memory disorders, placidity, loss of people recognition,

bulimia. Several symptoms responded dramatically to carbamazepine. We

conclude that it may be a useful agent in treatment of this unusual syndrome.

114. Grachev, I. D. MRI-based morphometric topographic parcellation of human

neocortex in trichotillomania. Psychiatry-Clin-Neurosci. 1997 Oct; 51(5): 315-21;

ISSN: 1323-1316.

AUSTRALIA. The purpose of the present study was to test specific

hypotheses regarding volumetric changes of the neocortex between 10 female

trichotillomania (TTM) subjects and 10 female normal controls. A standard three-

dimensional (3-D) brain coordinate system was imposed over each newly acquired

native magnetic resonance imaging (MRI) scan for positional normalization and 3-

D shape/geometric localization analyses were based on the midpoints of anterior

and posterior commissures, and the longitudinal fissure. The brain segmentation

method, using well-characterized semiautomated intensity and differential contour

algorithms by signal intensity-frequency histograms, was used blind to segment

the principal gray and white matter structures. The segmented neocortical ribbon

was subdivided into 48 regions (i.e. parcellation units) per hemisphere via a new

method of morphometric topographic parcellation. There were no significant

volumetric changes of the precentral gyrus, postcentral gyrus, supplementary

motor cortex or opercular cortex in TTM patients compared with control

subjects. A broader analysis as a hypothesis-generating post-hoc effort showed

that TTM subjects exhibited significantly reduced left inferior frontal gyrus

volume of 27% (t = 2.21, d.f. = 18, P = 0.04) and enlarged right cuneal cortex

volume of 40% (t = -2.30, d.f. = 18, P = 0.03) compared to normal controls. This

is the first report of a structural neocortex abnormality in TTM. Results are

discussed in terms of the behavioral specialization of these two brain neocortical

regions and the complex interractions between visual and sensorimotor cortices.

The results also showed the feasibility of the MRI-based morphometric

topographic parcellation for investigation of the human neocortex in neuroscience

research.

115. Grady, C. L.; Van Meter, J. W.; Maisog, J. M.; Pietrini, P.; Krasuski, J.; Rauschecker,

J. P. Attention-related modulation of activity in primary and secondary auditory

cortex. Neuroreport. 1997 Jul 28; 8(11): 2511-6; ISSN: 0959-4965.

ENGLAND. We investigated the effects of auditory attention on brain activity

using functional magnetic resonance imaging. Subjects listened to three word lists,

three times each, and were instructed to count the number of times they heard a

target word during two of these presentations. For the third, they listened to the

words without counting. All subjects showed significant areas of activation in

auditory cortex during the listening conditions compared to rest. There was

significantly more activation and a larger area of activation, particularly in

association cortex, in the left temporal lobe during counting of targets compared to

the no-target conditions, with a similar trend in the right hemisphere. These

results provide evidence of an attention-related enhancement of both activation

magnitude and extent in auditory cortex.

116. Grafton, S. T.; Fadiga, L.; Arbib, M. A.; Rizzolatti, G. Premotor cortex activation

during observation and naming of familiar tools. Neuroimage. 1997 Nov; 6(4):

231-6; ISSN: 1053-8119.

UNITED-STATES. Positron emission tomography was used to investigate

whether observation of real objects (tools of common use) activates premotor

areas in the absence of any overt motor demand. Silent naming of the presented

tools and silent naming of their use were also studied. Right-handed normal

subjects were employed. Tool observation strongly activated the left dorsal

premotor cortex. In contrast, silent tool naming activated Broca's area without

additional activity in the dorsal premotor cortex. Silent tool-use naming, in

addition to activating Broca's area, increased the activity in the left dorsal

premotor cortex and recruited the left ventral premotor cortex and the left

supplementary motor area. These data indicate that, even in the absence of any

subsequent movement, the left premotor cortex processes objects that, like tools,

have a motor valence. This dorsal premotor activation, which further augments

when the subject names the tool use, should reflect the neural activity related to

motor schemata for object use. The presence of an activation of both dorsal

premotor cortex and ventral premotor cortex during tool-use naming suggests a

role for these two areas in understanding object semantics. Copyright 1997

Academic Press.

117. Gratton, G.; Fabiani, M.; Corballis, P. M.; Hood, D. C.; Goodman Wood, M. R.;

Hirsch, J.; Kim, K.; Friedman, D.; Gratton, E. Fast and localized event-related

optical signals (EROS) in the human occipital cortex: comparisons with the visual

evoked potential and fMRI. Neuroimage. 1997 Oct; 6(3): 168-80; ISSN: 1053-

8119.

UNITED-STATES. Localized evoked activity of the human cortex produces fast

changes in optical properties that can be detected noninvasively (event-related

optical signal, or EROS). In the present study a fast EROS response (latency

approximately 100 ms) elicited in the occipital cortex by visual stimuli showed

spatial congruence with fMRI signals and temporal correspondence with VEPs,

thus combining subcentimeter spatial localization with subsecond temporal

resolution. fMRI signals were recorded from striate and extrastriate cortex. Both

areas showed EROS peaks, but at different latencies after stimulation (100 and

200-300 ms, respectively). These results suggest that EROS manifests localized

neuronal activity associated with information processing. The temporal resolution

and spatial localization of this signal make it a promising tool for studying the

time course of activity in localized brain areas and for bridging the gap between

electrical and hemodynamic imaging methods. Copyright 1997 Academic Press.

118. Graziani, L. J.; Gringlas, M.; Baumgart, S. Cerebrovascular complications and

neurodevelopmental sequelae of neonatal ECMO. Clin-Perinatol. 1997 Sep; 24(3):

655-75; ISSN: 0095-5108.

UNITED-STATES. A total of 355 infants have been treated with ECMO at our

hospital between 1985 and 1996, 271 of whom have been enrolled in an ongoing

prospective study; of the 271 infants enrolled, 223 (82%) survived, and most

function within the normal range of development. Nevertheless, handicapping

sequelae, including spastic forms of CP, hearing loss, and cognitive deficiencies at

school age, have been noted in a significant minority of ECMO-treated survivors.

The need for RCCA cannulation during venoarterial ECMO may increase the risk

of a cerebrovascular injury, and lateralized CBF abnormalities have been noted on

CDI and pulsed Doppler ultrasound studies during and after venoarterial bypass;

however, post-ECMO CT scans, HUS, MR images, or clinical evaluations have

not indicated selective or greater injury to the right, compared with the left,

cerebral hemisphere in our survivors, nor was there a significant predilection for

right, rather than left, cerebral hemispheric EEG abnormalities during or following

venoarterial bypass. Although we routinely repair the RCCA following

venoarterial ECMO, the long-term consequences of a permanently ligated artery

have not as yet been demonstrated. We have noted the ominous predictive value

of two or more recordings that disclose ES and BS EEG abnormalities before or

during venoarterial ECMO and found that the need for vigorous CPR before or

during RCCA cannulation significantly increased the risk of these two markedly

abnormal bioelectric patterns. Because 85% of infants with severe respiratory

failure have moderate to marked EEG abnormalities (including 23% who have BS

or ES patterns) before ECMO, we believe that fetal and neonatal complications

related to the occurrence and treatment of severe cardiorespiratory failure are

responsible in large part for the neurologic sequelae in ECMO survivors. The risk

for CP was significantly increased in survivors of neonatal venoarterial ECMO

treated at our hospital who required CPR or who independently had a systolic BP

below 39 mm Hg before or during ECMO. We also noted that the risk for hearing

loss was increased significantly in surviving neonates who had a PaCO2 below 14

mm Hg before ECMO. The possibility that undetected confounding variables

were, in part, responsible for the neurologic, audiologic, and cognitive sequelae in

ECMO survivors could not be excluded entirely by our data analyses. Although

the pathogenesis of severe brain damage has not been defined fully in neonates

treated with ECMO, focal, multifocal, or diffuse cerebral ischemia is the most

likely final common pathway; thrombosis, infarction, or hemorrhage may follow

and contribute to the brain injury. The cause of isolated SNHL is unknown in

most affected ECMO survivors, but in some very likely is associated with the

complications and treatment of severe cardiorespiratory failure, including

profound hypocarbia prior to ECMO. The results of our studies to date are

consistent with the following conclusions: (1) hypotension before or during

ECMO and the need for CPR before ECMO contribute to the pathogenesis of

CP, probably through the mechanism of cerebral ischemia; (2) profound

hypocarbia before ECMO and delayed ECMO treatment are associated with a

significantly increased risk of hearing loss; (3) hypoxemia without hypotension

does not result in CP; (4) the type and severity of neurologic and cognitive

sequelae in ECMO survivors depends, in part, on the primary cause of the

neonatal cardiorespiratory failure; (5) early neurodevelopment, except for severe

deficits, may not predict school-age performance; and (6) abnormally low or

borderline WPPSI-R IQ scores and academic deficiencies at early school age,

without evidence of a congenital abnormality of brain or CP or SNHL, remain

unexplained. The criteria for initiating ECMO in the neonate with severe

cardiorespiratory failure include decreasing oxygenation despite mechanical

hyperventilation with 100% oxygen. (ABSTRACT TRUNCATED).

119. Gruetter, R.; Ugurbil, K.; Seaquist, E. R. Steady-state cerebral glucose concentrations

and transport in the human brain. J-Neurochem. 1998 Jan; 70(1): 397-408; ISSN:

0022-3042.

UNITED-STATES. Understanding the mechanism of brain glucose transport

across the blood-brain barrier is of importance to understanding brain energy

metabolism. The specific kinetics of glucose transport have been generally

described using standard Michaelis-Menten kinetics. These models predict that

the steady-state glucose concentration approaches an upper limit in the human

brain when the plasma glucose level is well above the Michaelis-Menten constant

for half-maximal transport, Kt. In experiments where steady-state plasma glucose

content was varied from 4 to 30 mM, the brain glucose level was a linear function

of plasma glucose concentration. At plasma concentrations nearing 30 mM, the

brain glucose level approached 9 mM, which was significantly higher than

predicted from the previously reported Kt of approximately 4 mM (p < 0.05).

The high brain glucose concentration measured in the human brain suggests that

ablumenal brain glucose may compete with lumenal glucose for transport. We

developed a model based on a reversible Michaelis-Menten kinetic formulation of

unidirectional transport rates. Fitting this model to brain glucose level as a

function of plasma glucose level gave a substantially lower Kt of 0.6 +/- 2.0 mM,

which was consistent with the previously reported millimolar Km of GLUT-1 in

erythrocyte model systems. Previously reported and reanalyzed quantification

provided consistent kinetic parameters. We conclude that cerebral glucose

transport is most consistently described when using reversible Michaelis-Menten

kinetics.. 50-99-7.

120. Gugliemotti, V.; Fiorino, L. Asymmetry in the left and right habenulo-interpeduncular

tracts in the frog. Brain-Res-Bull. 1998; 45(1): 105-10; ISSN: 0361-9230.

UNITED-STATES. In the frog Rana esculenta the left dorsal habenula includes a

lateral and a medial component, whereas the right dorsal habenula is only

represented by one nucleus. The efferents of the habenular nuclei to the

interpeduncular nucleus were herein investigated with the retrograde horseradish

peroxidase tracing. Injections of cobaltic-lysine complex in the interpeduncular

nucleus were also performed. Intensely labeled fibers of the fasciculus retroflexus

on the right and left sides of the brain were found to reach the interpeduncular

nucleus from the habenular nuclei running prevalently in two routes--one through

the medial, and the other through the lateral region of the diencephalon. On the

right side, these fibers originated from the entire dorsal habenula. On the left side,

the fibers of the medial route derived from the medial habenular subnucleus, while

those of the lateral route derived from the lateral habenular subnucleus. In the

dorsal habenulae of both sides, a large number of neurons displayed a Golgi-like

labeling, while few such cells were detected in the ventral habenulae. Labeled

neurons in the right dorsal habenula resembled those labeled in the lateral

subnucleus of the left dorsal habenula, while larger and ramified neurons were

detected in the left medial subnucleus. The present findings provide the first

description of the pathway originating from the medial and the lateral subnucleus

of the left dorsal habenula in the frog and point out that projection neurons of the

medial habenular subnucleus are morphologically different from those of the other

habenular nuclei. The present data indicate that in the frog the habenular

asymmetry could underlie distinct functional correlates of the left and right

habenulae.. EC 1.11.1.-; 0; 56-87-1.

121. Gunduz, K.; Gunalp, I.; Erden, I. Focal dermal hypoplasia (Goltz's syndrome).

Ophthalmic-Genet. 1997 Sep; 18(3): 143-9; ISSN: 0167-6784.

NETHERLANDS. A 17-year-old female with Goltz's syndrome was examined

because of visual acuity loss in her right eye. Ocular examination revealed

microcornea, iris, choroid and optic disc coloboma in the right eye. There were

several erthematous and hyperpigmented areas on the body. Magnetic resonance

(MR) imaging of the orbits and brain demonstrated right optic nerve hypoplasia

and diffuse cortical and cerebellar atrophy. Skeletal manifestations were short

stature, scoliosis, syndactyly, clinodactyly, and osteopathia striata. Dental

defects included hypodontia, developmental defects, and malocclusion. There

were multiple papillomatous lesions on the lids and perioral skin and the nose was

asymmetric. Her mental development was apparently normal. She had left bifid

ureter and renal pelvis, scant hair on the pubic and genital region, and poor breast

development. Histopathologic examination of the biopsy taken from a

characteristic skin lesion revealed attenuated epidermis, hypoplastic dermis, and

subcutaneous fat close to epidermis. Immunofluorescence staining was negative

for IgG, IgM, IgA, C3, C4, fibrin, and albumin. Ultrastructural examination

showed that no viral particles were present. Prometaphase chromosome analysis

revealed a normal 46, XX female karyotype. Cortical and cerebellar atrophy can

occur in a patient with Goltz's syndrome.

122. Gunturkun, O. Morphological asymmetries of the tectum opticum in the pigeon. Exp-

Brain-Res. 1997 Oct; 116(3): 561-6; ISSN: 0014-4819.

GERMANY. Pigeons are visually lateralized with a dominance of the right eye.

Due to the virtually complete decussation of the optic nerves in birds, a right eye

superiority probably depends on a left brain hemisphere dominance. The aim of

the present study was to analyze whether morphological asymmetries in the

cross-sectional area of perikarya can be found within the retina and the optic

tectum. With an image-analyzing system the cross-sectional areas of the somata of

retinal ganglion cells and tectal neurons were measured in the left and the right side

under blind conditions. The results reveal significant morphological left-right

differences, with cells in superficial layers 2-12 being larger on the left side while

neurons in laminae 13-15 have larger somata in the right tectum. No retinal

asymmetries could be revealed. Since pigeon embryos keep their head turned to

the right within the egg, such that the right eye is stimulated by light shining

through the shell, it is possible that the morphological asymmetries at the tectal

level are induced by left-right differences in prehatching photic stimulation. This

embryonic sensory asymmetry might lead to a higher activity level of right eye

ganglion cells and to a larger amount of released neurotrophins in the left tectum.

This in turn could exert the morphological effects on soma sizes in the superficial

retinorecipient layers.

123. Hadjikhani, N.; Roland, P. E. Cross-modal transfer of information between the tactile

and the visual representations in the human brain: A positron emission

tomographic study. J-Neurosci. 1998 Feb 1; 18(3): 1072-84; ISSN: 0270-6474.

UNITED-STATES. Positron emission tomography in three-dimensional

acquisition mode was used to identify the neural populations involved in tactile-

visual cross-modal transfer of shape. Eight young male volunteers went through

three runs of three different matching conditions: tactile-tactile (TT), tactile-visual

(TV), and visual-visual (VV), and a motor control condition. Fifteen spherical

ellipsoids were used as stimuli. By subtracting the different matching conditions

and calculating the intersections of statistically significant activations, we could

identify cortical functional fields involved in the formation of visual and tactile

representation of the objects alone and those involved in cross-modal transfer of

the shapes of the objects. Fields engaged in representation of visual shape,

revealed in VV-control, TV-control and TV-TT, were found bilaterally in the

lingual, fusiform, and middle occipital gyri and the cuneus. Fields engaged in the

formation of the tactile representation of shape, appearing in TT-control, TV-

control and TV-VV, were found in the left postcentral gyrus, left superior parietal

lobule, and right cerebellum. Finally, fields active in both TV-VV and TV-TT were

considered as those involved in cross-modal transfer of information. One field was

found, situated in the right insula-claustrum. This region has been shown to be

activated in other studies involving cross-modal transfer of information. The

claustrum may play an important role in cross-modal matching, because it receives

and gives rise to multimodal cortical projections. We propose here that modality-

specific areas can communicate, exchange information, and interact via the

claustrum.

124. Hadjikhani, N.; Roland, P. E. Cross-modal transfer of information between the tactile

and the visual representations in the human brain: A positron emission

tomographic study. J-Neurosci. 1998 Feb 1; 18(3): 1072-84; ISSN: 0270-6474.

UNITED-STATES. Positron emission tomography in three-dimensional

acquisition mode was used to identify the neural populations involved in tactile-

visual cross-modal transfer of shape. Eight young male volunteers went through

three runs of three different matching conditions: tactile-tactile (TT), tactile-visual

(TV), and visual-visual (VV), and a motor control condition. Fifteen spherical

ellipsoids were used as stimuli. By subtracting the different matching conditions

and calculating the intersections of statistically significant activations, we could

identify cortical functional fields involved in the formation of visual and tactile

representation of the objects alone and those involved in cross-modal transfer of

the shapes of the objects. Fields engaged in representation of visual shape,

revealed in VV-control, TV-control and TV-TT, were found bilaterally in the

lingual, fusiform, and middle occipital gyri and the cuneus. Fields engaged in the

formation of the tactile representation of shape, appearing in TT-control, TV-

control and TV-VV, were found in the left postcentral gyrus, left superior parietal

lobule, and right cerebellum. Finally, fields active in both TV-VV and TV-TT were

considered as those involved in cross-modal transfer of information. One field was

found, situated in the right insula-claustrum. This region has been shown to be

activated in other studies involving cross-modal transfer of information. The

claustrum may play an important role in cross-modal matching, because it receives

and gives rise to multimodal cortical projections. We propose here that modality-

specific areas can communicate, exchange information, and interact via the

claustrum.

125. Hamada, H.; Takahashi, H.; Teramoto, A.; Yoshii, T. [Effect of arginine vasopressin

(AVP) inhibitor in the inhibition of the peritumoral edema]. No-To-Shinkei. 1997

Nov; 49(11): 1001-6; ISSN: 0006-8969.

JAPAN. We investigated the effect of RU599 Arginine Vasopressin (AVP)

inhibitor on peritumoral edema of Wistar rats implanted with C6 glioma. C6

glioma was implanted into the right caudoputamen of 3 week-old rat's brain. Five

weeks after the implantation, the changes of the brain water contents were

measured by the dry-weight method. RU599 (1 mg/ml/kg body weight) was

administered into Wistar rats via the tail vein every one hour (total 4 times), and

the same dose of saline was used as control. Rats were sacrificed 1 hour after the

last administration, and the brain of each rat was divided into 3 parts such as the

anterior part without a tumor, the middle part with a tumor and the posterior part

without a tumor. After that each part was separated into the right and left parts.

The tumor was removed from the brain. The water contents of the brain were

increased in the area around the tumor and the contralateral cerebral hemisphere

excluding the anterior part. RU599 could reduce the increased water contents

significantly in all areas except in the tumor itself and the area surrounding the

tumor. Tumor-origin brain edema includes not only localized one but also diffuse

one in the brain, and this study suggests RU599 has an effect of inhibiting the

diffuse brain edema.. 0; 0; 0; 113-79-1.

126. Hamlyn, P. J. Neurovascular relationships in the posterior cranial fossa, with special

reference to trigeminal neuralgia. 1. Review of the literature and development of a

new method of vascular injection-filling in cadaveric controls. Clin-Anat. 1997;

10(6): 371-9; ISSN: 0897-3806.

UNITED-STATES. Vascular compression of cranial nerves adjacent to the brain

stem has been implicated in a wide variety of disorders affecting their function.

The considerable conflicts in published results relate primarily to flaws in study

design. The design required of an adequate study is defined and a technique is

presented, in 16 fresh human cadavers, of reliable and physiological injection-

filling of both the cerebral arterial and venous systems. It allowed for the accurate

observation of the normal neurovascular relationships in the posterior cranial

fossa during operative simulation. Part 2 of this article concerns the use of this

design in the study of trigeminal neuralgia, a disorder thought to relate to vascular

compression of the fifth cranial nerve.. 0.

127. Hanke, J.; Yilmazer Hanke, D. M. Variabilities in the distribution of neurofibrillary

tangles in the anterior parahippocampal gyrus at initial stages of Alzheimer's

disease. Clin-Neuropathol. 1997 Nov; 16(6): 299-302; ISSN: 0722-5091.

GERMANY. The entorhinal region is located in the ventromedial surface of the

temporal lobe on the parahippocampal gyrus. Occurrence of early argyrophilic

neurofibrillary tangles was investigated in brain sections of the left and right

entorhinal region of 9 individuals of both sexes between the age of 26 to 54 years.

Parasagittal serial sections at 100 microns were performed to include the very

anterior part of the entorhinal region. An advanced silver method was used for

staining neurofibrillary changes. The neurofibrillary tangles were counted via light

microscopy, marked on the sections and staged as proposed by Braak and Braak.

In 1 case we found a left-right difference by 1 stage (right: stage I, left: stage II).

The tangle distribution in another case exhibited several neurofibrillary tangles

only in the very anterior part of the entorhinal cortex on both sides (stage 0). In 3

cases some neurofibrillary tangles occurred in the very anterior part of the right

entorhinal region, while a few are present in more posterior parts (stage I). The

corresponding left hemisphere showed the same anterior-posterior distribution

pattern as on the right in only 1 of these cases. In the remaining 4 cases, no

neurofibrillary changes were visible. In conclusion, the very anterior part of the

entorhinal region is among the earliest sites for development of neurofibrillary

tangles. Distribution of early Alzheimer-related neurofibrillary changes in the

entorhinal region displays variabilities in the anterior-posterior direction as well as

in a left-right comparison.

128. Hari, R.; Nagamine, T.; Nishitani, N.; Mikuni, N.; Sato, T.; Tarkiainen, A.; Shibasaki,

H. Time-varying activation of different cytoarchitectonic areas of the human SI

cortex after tibial nerve stimulation. Neuroimage. 1996 Oct; 4(2): 111-8; ISSN:

1053-8119.

UNITED-STATES. We followed cortical activation in eight healthy adults after

electric stimulation of the left tibial nerve at the ankle. The recordings were made

noninvasively with a whole-scalp neuromagnetometer. The first cortical activation

peaked in different subjects at 37-45 ms in the foot area of the right (contralateral)

primary somato-sensory (SI) cortex, with mean source current orientation

perpendicular to the longitudinal fissure. The current orientation changed within

the next 5 ms counterclockwise in all subjects, with a mean rotation of 64 degrees.

A two-dipole time-varying model, with two dipoles differing by 28-119 degrees in

orientation but less than 1 cm in location in the right SI cortex, explained the signal

pattern satisfactorily during the first 100 ms. We suggest that the observed field

patterns reflect sequential activation of different cytoarchitectonic areas in the

foot SI cortex and imply considerable differences in the structural organization

between the foot and the hand SI cortices. The initial activation is considered to

take place in area 3b facing the interhemispheric fissure, and the later source, due

to the systematic rotations of the field patterns, is assumed to reflect activation of

area 5 in the anterior wall of the marginal ramus of the cingulate sulcus.

129. Harrington, D. L.; Haaland, K. Y.; Knight, R. T. Cortical networks underlying

mechanisms of time perception. J-Neurosci. 1998 Feb 1; 18(3): 1085-95; ISSN:

0270-6474.

UNITED-STATES. Precise timing of sensory information from multiple sensory

streams is essential for many aspects of human perception and action. Animal and

human research implicates the basal ganglia and cerebellar systems in timekeeping

operations, but investigations into the role of the cerebral cortex have been limited.

Individuals with focal left (LHD) or right hemisphere (RHD) lesions and control

subjects performed two time perception tasks (duration perception, wherein the

standard tone pair interval was 300 or 600 msec) and a frequency perception task,

which controlled for deficits in time-independent processes shared by both tasks.

When frequency perception deficits were controlled, only patients with RHD

showed time perception deficits. Time perception competency was correlated

with an independent test of switching nonspatial attention in the RHD but not the

LHD patients, despite attention deficits in both groups. Lesion overlays of

patients with RHD and impaired timing showed that 100% of the patients with

anterior damage had lesions in premotor and prefrontal cortex (Brodmann areas 6,

8, 9, and 46), and 100% with posterior damage had lesions in the inferior parietal

cortex. All LHD patients with normal timing had damage in these same regions,

whereas few, if any, RHD patients with normal timing had similar lesion

distributions. These results implicate a right hemisphere prefrontal-inferior

parietal network in timing. Time-dependent attention and working memory

functions may contribute to temporal perception deficits observed after damage to

this network.

130. Hashimoto, Y.; Terasaki, T.; Hara, Y.; Yonehara, T.; Uchino, M. [Cerebral embolism

due to lone atrial septal aneurysm]. Rinsho-Shinkeigaku. 1997 Sep; 37(9): 851-3;

ISSN: 0009-918X.

JAPAN. A 71-year-old man was admitted to our hospital because of headache

and left hemiparesis. Brain CT scan showed hemorrhagic infarction of the right

frontal lobe. Intravenous digital subtraction angiography revealed no occlusion of

cerebral arteries. No arrhythmias were observed by the holter ECG. Transthoracic

echocardiography showed no abnormalities. Anticoagulation therapy (heparin and

warfarin) was started under the diagnosis of cerebral embolism without definite

embolic source and there was no recurrence during following four years.

Transesophageal echocardiography showed an atrial septal aneurysm (ASA)

without patent foramen ovale. A potential cause of cerebral embolism due to atrial

septal aneurysm is paradoxical embolization through an interatrial shunt (patent

foramen ovale). It was speculated that ASA was a direct source of thrombus

formation in this case (lone ASA). Transesophageal echocardiography should be

performed to find atrial septal aneurysm in patients with cryptogenic stroke,

especially embolic stroke without definite embolic sources.

131. Hassanali, J. Quantitative and somatotopic mapping of neurones in the trigeminal

mesencephalic nucleus and ganglion innervating teeth in monkey and baboon.

Arch-Oral-Biol. 1997 Oct; 42(10-11): 673-82; ISSN: 0003-9969.

ENGLAND. Neurones of the trigeminal mesencephalic nucleus (Mes V) and

ganglion innervating the periodontium of incisor, canine and molar teeth in 10

monkeys and 10 baboons were counted and mapped using the horseradish

peroxidase (Hrp), retrograde axonal transport method. Periodontal afferent

neurones of all these teeth were well represented in the Mes V, although the

incisors had a significantly higher number of labelled neurones than the canines or

molars. The primary cell bodies of the periodontal afferents were located mainly

in the caudal part of the ipsilateral Mes V from the level of the inferior colliculus

to the floor of the fourth ventricle in the pons. The caudal periodontal Mes V

neurones may be favourably located to make collateral connections with the

trigeminal motor nucleus for jaw reflexes. Incisors and canines had a large and

predominantly ipsilateral representation of Hrp-labelled neurones in the ganglion.

In contrast, molar representation in the ganglion was sparse and all labelled

neurones supplied ipsilateral teeth. The maxillary and mandibular teeth had a

somatotopic distribution within the respective maxillary (middle) and mandibular

(posterolateral) compartments of the trigeminal ganglion. It is suggested that the

anterior teeth with greater connections to the Mes V and the ganglion may impart

greater sensory perception and be involved in jaw reflexes to ensure a good

occlusal relation during mastication, while the afferent connections of the molars

may initiate complex jaw reflexes during the occlusal phase of mastication.. EC

1.11.1.-.

132. Hayashi, N.; Nishijo, H.; Endo, S.; Ono, T. Three-dimensional localization of dipoles

for potentials evoked by posterior tibial nerve stimulation in the monkey. Brain-

Res. 1997 Nov 7; 774(1-2): 44-50; ISSN: 0006-8993.

NETHERLANDS. Somatosensory evoked potentials (SEPs) elicited by right

posterior tibial nerve stimulation were simultaneously recorded from 21-27

epidural electrodes in three monkeys. N23-P40 was recorded anterior to the left

central sulcus, and P23-N40 was recorded on the parietal midline and the middle

portion of the right hemisphere. These potentials were thought to be the primary

cortical responses elicited by posterior tibial nerve stimulation in the monkey,

since a topographical map made of them corresponded to the paradoxical

lateralization of the primary cortical components in human posterior tibial nerve

SEPs. Current source generators (dipoles) of these potentials were 3-

dimensionally identified dipoles located in the left side of the mesial wall of the

anterior parietal cortex, and oriented obliquely toward the right hemisphere by a

dipole tracing (DT) method in which the 3-dimensional localization of dipoles in

the brain were estimated and superimposed on magnetic resonance imaging (MRI)

images.

133. Hayashi, N.; Nishijo, H.; Endo, S.; Ono, T. Three-dimensional localization of dipoles

for potentials evoked by posterior tibial nerve stimulation in the monkey. Brain-

Res. 1997 Nov 7; 774(1-2): 44-50; ISSN: 0006-8993.

NETHERLANDS. Somatosensory evoked potentials (SEPs) elicited by right

posterior tibial nerve stimulation were simultaneously recorded from 21-27

epidural electrodes in three monkeys. N23-P40 was recorded anterior to the left

central sulcus, and P23-N40 was recorded on the parietal midline and the middle

portion of the right hemisphere. These potentials were thought to be the primary

cortical responses elicited by posterior tibial nerve stimulation in the monkey,

since a topographical map made of them corresponded to the paradoxical

lateralization of the primary cortical components in human posterior tibial nerve

SEPs. Current source generators (dipoles) of these potentials were 3-

dimensionally identified dipoles located in the left side of the mesial wall of the

anterior parietal cortex, and oriented obliquely toward the right hemisphere by a

dipole tracing (DT) method in which the 3-dimensional localization of dipoles in

the brain were estimated and superimposed on magnetic resonance imaging (MRI)

images.

134. Hellige, J. B.; Scott, G. B. Effects of output order on hemispheric asymmetry for

processing letter trigrams. Brain-Lang. 1997 Oct 1; 59(3): 523-30; ISSN: 0093-

934X.

UNITED-STATES. Observers identified consonant-vowel-consonant trigrams

with the letters arranged vertically by pronouncing the stimulus (treating the

bottom letter as the first letter) and spelling it from bottom to top. On each trial,

the trigram was presented to the left visual field/right hemisphere (LVF/RH), to

the right visual field/left hemisphere (RVF/LH), or to both visual fields

simultaneously (BILATERAL trials). Quantitative and qualitative visual field

differences were identical to those found when observers used a more natural

response output order, treating the top letter of the trigram as the first letter. The

results suggest that, regardless of output order, attention is distributed across the

three letters in a relatively slow, top-to-bottom fashion on LVF/RH and

BILATERAL trials, whereas attention is distributed more rapidly and evenly

across the three letters on RVF/LH trials.

135. Helmstaedter, C.; Grunwald, T.; Lehnertz, K.; Gleissner, U.; Elger, C. E. Differential

involvement of left temporolateral and temporomesial structures in verbal

declarative learning and memory: evidence from temporal lobe epilepsy. Brain-

Cogn. 1997 Oct; 35(1): 110-31; ISSN: 0278-2626.

UNITED-STATES. A wealth of animal and human research has pointed to a

significant involvement of the temporal lobes in memory processing, and yet the

different functional roles of temporal cortical vs. mesial structures remain unclear.

We studied verbal declarative memory, by using a word list paradigm that

differentiates among learning (immediate recall), memory (delayed recall), and

recognition, in epilepsy patients being considered for surgical resection of the left

temporal lobe. Verbal memory was evaluated preoperatively and during the

recording of intracranial event related potentials and postoperatively after

selective hippocampectomy, temporal cortical lesionectomy, or anterior two-

thirds en bloc temporal lobe resection procedures. Preoperative differences in

verbal memory performance as a function of differences in underlying

neuropathology, concurrent event-related potentials, and specific patterns of

postoperative memory impairments lead to converging evidence that verbal

declarative memory relies on a synergistic interaction of at least two functionally

distinct brain systems. Material-specific data acquisition, or working memory, is

mediated by neocortical temporal structures, whereas long-term

consolidation/retrieval is particularly mediated by temporomesial structures. In

contrast to the left temporal neocortex, the function of the temporomesial system

appears to be material nonspecific. Apparently, its preferential involvement in

verbal memory is due to its close interaction with overlying neocortical structures

that are specialized for language processing.

136. Henriques, J. B.; Davidson, R. J. Brain electrical asymmetries during cognitive task

performance in depressed and nondepressed subjects. Biol-Psychiatry. 1997 Dec

1; 42(11): 1039-50; ISSN: 0006-3223.

UNITED-STATES. BACKGROUND: Studies using electroencephalogram

(EEG) measures of activation asymmetry have reported differences in anterior

asymmetry between depressed and nondepressed subjects. Several studies have

suggested reciprocal relations between measures of anterior and posterior

activation asymmetries. We hypothesized that depressed subjects would fail to

show the normal activation of posterior right hemisphere regions in response to an

appropriate cognitive challenge. METHODS: EEG activity was recorded from 11

depressed and 19 nondepressed subjects during the performance of

psychometrically matched verbal (word finding) and spatial (dot localization)

tasks. Band power was extracted from all epochs of artifact-free data and averaged

within each condition. Task performance was also assessed. RESULTS:

Depressed subjects showed a specific deficit in the performance of the spatial

task, whereas no group differences were evident on verbal performance. In

posterior scalp regions, nondepressed controls had a pattern of relative left-sided

activation during the verbal task and relative right-sided activation during the

spatial task. In contrast, depressed subjects failed to show activation in posterior

right hemisphere regions during spatial task performance. CONCLUSIONS:

These findings suggest that deficits in right posterior functioning underlie the

observed impairments in spatial functioning among depressed subjects.

137. Henry, J. P. Psychological and physiological responses to stress: the right hemisphere

and the hypothalamo-pituitary-adrenal axis, an inquiry into problems of human

bonding. Acta-Physiol-Scand-Suppl. 1997; 640: 10-25; ISSN: 0302-2994.

ENGLAND. In addition to repeated reexperiencing of the event, the delayed

effects of severe psychological trauma, i.e., post traumatic stress disorder

(PTSD), present a paradoxical mix of symptoms. There is enhancement of the

self-preservative catecholamine states; anger and fear with a contrasting sense of

meaninglessness and blunting of the emotional responses of the attachment

behavior so critical for species preservation. Hormonally, there is a striking

separation of the catecholamine response, which stays elevated and that of the

hypothalamo-pituitary-adrenal (HPA) axis, which may remain at normal levels.

Pathophysiologically, the reexperienceing of the trauma and the arousal may be

associated with dysfunction of the locus coeruleus, amygdala and hippocampal

systems. This article explores the consequences of an additional dysfunction: a

dissociation of the hemispheres that appears to be responsible for the alexithymic

avoidance and failure of the cortisol response that so often follow severe

psychological trauma. There is neurophysiological evidence that the left the right

hemispheres subserve different emotional sets that correspond to "control" and

"appraisal," i.e., very approximately to the self and species preservative

behavioral complexes, respectively. Several studies point to physiological

dissociation of hemispheric functions during alexithymia. This raises the question:

What has been lost if in this condition the right side no longer fully contributes to

integrated cerebral function? Right hemispheric damaged children lose critical

social skills and in adults the related sense of familiarity critical for bonding is lost.

Such losses of social sensibilities may account for the lack of empathy and

difficulties with bonding found in sociopathy and borderline personality:

conditions now believed to result from repeated psychological trauma during

development. On the other hand, systems that promote right hemispheric

contributions provide solacing access to a "Higher Power." They also appear to

protect against socially disordered behavior, substance abuse, the failure of the

HPA axis and some aspects of the pathophysiology of chronic disease.

138. Herholz, K.; Thiel, A.; Wienhard, K.; Pietrzyk, U.; von Stockhausen, H. M.; Karbe,

H.; Kessler, J.; Bruckbauer, T.; Halber, M.; Heiss, W. D. Individual functional

anatomy of verb generation. Neuroimage. 1996 Jun; 3(3 Pt 1): 185-94; ISSN:

1053-8119.

UNITED-STATES. Examination of the individual functional anatomy of language

is of particular interest in clinical neurology to explain the variability of aphasic

symptoms after focal lesions and to avoid damage of language-related brain areas

by surgery. For a silent verb generation task, we examined whether activation PET

with 3D data acquisition, multiple replication of conditions, and coregistration

with MRI provides results that are consistent and reproducible enough to be

useful clinically. Visual analysis was performed on PET-MRI fusion images,

including renderings of the brain surface. Quantitative analysis was based on

volumes of interest. In seven right-handed normals, activation of the triangular

part of the left inferior frontal cortex [Brodman area (BA) 45] was the most

significant finding that was present in each subject. Two subjects showed minor

anatomical variants of the ascending or horizontal ramus of the sylvian fissure that

were associated with the least activation of BA 45. In the left hemisphere the

other frontal gyri, the superior temporal and posterior part of the middle temporal

gyrus, and the paracingulate gyrus were also significantly activated. There was

significant bilateral cerebellar activation, but it was significantly more intense on

the right than on the left side. The consistency and high interindividual

reproducibility of these findings suggest that this technique may be useful for

clinical assessment of language-related areas.

139. Heyne, J. P.; Schleicher, C.; Soldner, J.; Neumann, R.; Kaiser, W. A. [Radiation

exposure of the ocular lens and thyroid gland in digital subtraction angiography of

brain-supplying arteries]. Strahlenexposition der Augenlinse und der Schilddruse

bei der Digitalen Subtraktionsangiographie der hirnversorgenden Arterien. Rofo-

Fortschr-Geb-Rontgenstr-Neuen-Bildgeb-Verfahr. 1997 Nov; 167(5): 479-85;

ISSN: 0936-6652.

GERMANY. PURPOSE: To find out the individual level of radiation exposure of

the ocular lens and thyroid gland during DSA of arteries supplying the brain,

considering the indication. MATERIAL AND METHOD: The study was

conducted on 72 patients during aortic arch and cerebral artery angiographies using

thermoluminescent dosimetry. RESULTS: During 20 aortic arch angiographies the

measured values were within non-critical limits, whereas during carotid, vertebral

or cerebral four-vessel angiography of the left ocular lens exposure values of more

than 500 mGy (max. 782 mGy) were stated in two of 52 cases. The highest

measured exposure relating to the right ocular lens was 126 mGy, to the thyroid

gland 88 mGy. However, in 51 of 52 cases thyroid gland doses of below 51 mGy

were measured. In 71 of 72 cases there was a lateral difference between right and

left lens exposure up to twice the measured dose for the right ocular lens during

aortic arch angiographies and up to sixteen-fold in respect of the left lens during

cerebral angiographies. CONCLUSION: In addition to the fluoroscopic time,

number of images, fade-in and zoom some other dose-influencing factors, radiation

geometry is especially decisive for organ exposure. The risk of cataracts or

thyroid gland carcinomas/hypothyrosis can be neglected with median values of 40

and 70 mGy relating to the ocular lens and 17 mGy for the thyroid gland during

cerebral angiographies.

140. Hopkins, D. F.; Williams, G. Insulin receptors are widely distributed in human brain

and bind human and porcine insulin with equal affinity. Diabet-Med. 1997 Dec;

14(12): 1044-50; ISSN: 0742-3071.

ENGLAND. Insulin receptors differing structurally from those in other tissues

have been demonstrated in brain from many species. Subtle differences in binding

properties have been reported between insulin receptors in brain and other

tissues, including differences in affinity of pig brain receptors for human and

porcine insulin. Insulin binding has been demonstrated in human cerebral cortex,

but insulin binding has not been characterized in other areas of human brain. We

have studied the binding of 125I labelled human insulin, and its displacement by

unlabelled human and porcine insulin, in homogenates prepared from human

hypothalamus, cerebral cortex and cerebellum obtained post-mortem from eight

non-diabetic subjects. Specific binding was demonstrated in all brain regions

studied, and displacement curves obtained with unlabelled human and porcine

insulin were identical. By contrast, unlabelled insulin-like growth factor-1 did not

significantly displace 125I labelled human insulin over the same concentration

range. We therefore conclude that insulin receptors are widely distributed in

human brain and do not differ in their affinity for human and porcine insulin.. 0;

0; 0; 11061-68-0; 67763-96-6.

141. Hopper, K. D.; Patel, S.; Cann, T. S.; Wilcox, T.; Schaeffer, J. M. The relationship of

age, gender, handedness, and sidedness to the size of the corpus callosum. Acad-

Radiol. 1994 Nov; 1(3): 243-8; ISSN: 1076-6332.

UNITED-STATES. OBJECTIVES: We correlated the area and size of the corpus

callosum, as measured by MR imaging, with the individual's handedness,

sidedness, age, and gender. MATERIALS AND METHODS: A total of 117

patients (59 male, 58 female) aged 15-75 years were selected for this study. This

included 12 persons who were either left-handed or ambidextrous. Each patient

was tested extensively to determine handedness and sidedness. Callosal areas and

thickness were measured and correlated with brain size. RESULTS: The body of

the corpus callosum decreases in size with age and is larger in right-handed

persons. The cross-sectional areas of the genu, splenium, and corpus callosum,

overall, do not vary significantly with respect to age, gender, sidedness, or

handedness. CONCLUSIONS: The size of the corpus callosum consistently

decreases with age. Otherwise, few statistical differences in callosal size relate to

gender, sidedness, or handedness.

142. Hornig, M.; Mozley, P. D.; Amsterdam, J. D. HMPAO SPECT brain imaging in

treatment-resistant depression. Prog-Neuropsychopharmacol-Biol-Psychiatry.

1997 Oct; 21(7): 1097-114; ISSN: 0278-5846.

ENGLAND. 1. There is little published research on brain function in treatment-

resistant depression (TRD). This study examined regional cerebral blood flow

using 99mTechnetium-hexamethylpropanolamine oxime (HMPAO) single photon

emission computed tomography in 8 patients with a history of TRD, 13

depressed patients without TRD (non-TRD) and 16 normal controls. 2. Relative

HMPAO activity in selected brain regions revealed a significant increase in

hippocampus-amygdala activity in TRD patients compared to non-TRD patients

and healthy controls. The mean value of relative HMPAO activity did not differ

in any other brain region, nor were there any differences in right-left symmetry

among the subject groups. 3. The observation of increased hippocampus-

amygdala HMPAO activity in TRD patients suggests that functional

abnormalities in limbic circuitry may play a role in the pathophysiology of

treatment-resistance.. 0; 0.

143. Hugdahl, K.; Carlsson, G.; Uvebrant, P.; Lundervold, A. J. Dichotic-listening

performance and intracarotid injections of amobarbital in children and adolescents.

Preoperative and postoperative comparisons. Arch-Neurol. 1997 Dec; 54(12):

1494-500; ISSN: 0003-9942.

UNITED-STATES. BACKGROUND: Dichotic listening (DL) to consonant-

vowel syllables is frequently used in clinical and experimental studies of brain

laterality. However, the paradigm of consonant-vowel syllables has not been

thoroughly validated through a comparison with injections of amobarbital sodium

(Amytal). OBJECTIVE: To validate the DL test for hemisphere dominance

preoperatively vs postoperatively with the results from intracarotid injections of

amobarbital (i.e., the Wada test) in epileptic children and adolescents. DESIGN

AND MAIN OUTCOME MEASURES: Patients were tested with DL

preoperatively and at 6-month follow-up. Correct reports in the DL tests were

entered in a stepwise discriminant analysis for calculation of correct classification

of hemisphere dominance with the results from the injections of amobarbital as

the grouping variable. Correct reports from the right and left ears on the

consonant-vowel DL test were compared preoperatively and postoperatively,

separated for the subjects with regard to language dominance in the left and right

hemispheres. SETTING: The Department of Pediatrics, Ostra Hospital,

University of Goteborg, Goteborg, Sweden. PATIENTS: Thirteen children and

adolescents between the ages of 10 and 19 years, who were surgically treated for

resistant epilepsy, were included in the study. The operated area corresponded

with morphological changes and functional dysfunctions according to findings

from computed tomography, magnetic resonance imaging, single photon emission

computed tomography, and electroencephalography. RESULTS: The results of

the Wada tests revealed that 10 subjects had left hemisphere language dominance,

with 3 subjects having right hemisphere language dominance. All 3 subjects with

right hemisphere language dominance showed a left ear advantage on the DL test

preoperatively and postoperatively, with 8 and 7 of the 10 subjects with left

hemisphere dominance showing a right ear advantage, preoperatively and

postoperatively, respectively. However, according to discriminant analysis,

knowledge of the DL performance led to a correct classification according to the

Wada test results in 12 (92%) of the 13 subjects. CONCLUSIONS: A

quantitative classification procedure like discriminant analysis may be more

sensitive when predicting hemisphere speech dominance from DL data than a

qualitative procedure based on the ear advantage dichotomy. The ear advantage

dichotomy may actually introduce arbitrary left-right categories that do not

correspond to the actual clustering of the data.. 57-43-2.

144. Hunt, P. J.; Richards, A. M.; Nicholls, M. G.; Yandle, T. G.; Doughty, R. N.;

Espiner, E. A. Immunoreactive amino-terminal pro-brain natriuretic peptide (NT-

PROBNP): a new marker of cardiac impairment. Clin-Endocrinol-Oxf. 1997 Sep;

47(3): 287-96; ISSN: 0300-0664.

ENGLAND. OBJECTIVE: Human brain natriuretic peptide-32 (BNP) (i.e.

proBNP(77-108)), the mature form of BNP and secreted predominantly by the

cardiac ventricle, is formed from a high molecular weight precursor, proBNP(1-

108). We have recently identified the aminoterminal form proBNP(1-76) (NT-

proBNP) in human plasma but its source, metabolism and production in

circulatory disorders are unknown. We have investigated the relationship between

immunoreactive (IR) NT-proBNP and BNP-32 in normal and hypertensive

subjects and in patients with cardiac impairment, as well as the regional plasma

concentrations in patients undergoing routine cardiac catheterization. DESIGN

AND PATIENTS: Plasma hormone measurements were made in 26 normal

subjects, 20 subjects with untreated mild hypertension and 111 treated patients

with a history of coronary heart disease and documented cardiac impairment (left

ventricular election fraction (LVEF) < 45% (mean 29%); 25 NYHA Class I, 65

Class II and 21 Class III). Regional blood sampling from the femoral artery,

femoral vein, renal vein and coronary sinus was undertaken in 14 patients

presenting for left and right cardiac catheterization studies in the course of

standard investigation for a range of cardiac disorders. MEASUREMENTS:

Plasma samples were assayed for IR NT-proBNP and IR BNP-32 (and atrial

natriuretic peptide (ANP) in the regional blood samples). In the patients with

cardiac impairment, LVEF was determined by gated radionuclide

ventriculography, exercise capacity was measured using a modified Naughton

multistage protocol and creatinine clearance was calculated from plasma creatinine,

age and weight. In the regional study, extraction ratios across the kidney and lower

limb (and step-ups across the heart) were calculated from plasma peptide

concentrations. RESULTS: In normal subjects mean IR NT-proBNP levels (10.8

+/- 1.3 pmol/L) were similar to levels of IR BNP-32 (9.7 +/- 0.5 pmol/L). In

hypertensive patients the levels of IR NT-proBNP and IR BNP-32 tended to be

higher than but were not significantly different from normal subjects. Both IR

NT-proBNP and IR BNP-32 were raised in NYHA Classes I, II and III compared

with normals (P < 0.001 for all) with higher levels of both BNP forms seen with

increasing cardiac impairment. The levels of IR NT-proBNP were greater than IR

BNP-32 in all NYHA Classes (P < 0.001) for all). Overall, the levels of IR NT-

proBNP (129 +/- 12 pmol/L) were 4-fold higher than concomitant BNP-32 levels

(29 +/- 2 pmol/L). Multivariate analysis showed that LVEF, exercise test time and

creatinine clearance were independent predictors of IR NT-proBNP. In all study

groups, the levels of IR NT-proBNP and IR BNP-32 levels were highly

correlated. Regional plasma sampling showed similar step-ups in IR NT-proBNP

and IR BNP-32 levels across the heart, together with similar extraction of both

BNP forms across the kidney and lower limb. For both BNP forms, these changes

across tissues were significantly less than for ANP. CONCLUSIONS: Plasma

levels of immunoreactive amino terminal-proBNP are raised in cardiac impairment,

including NYHA Class I, and rise with increasing cardiac decompensation.

Metabolism and tissue uptake of immunoreactive amino terminal-proBNP and

immunoreactive BNP-32 appear similar. In cardiac impairment the proportional

and absolute increment above normal levels of the aminoterminal BNP peptide

exceeds that for BNP-32 and suggest that amino terminal-proBNP may be a more

discerning marker of early cardiac dysfunction than BNP-32.. 0; 0; 0; 117217-27-

3.

145. Huppi, P. S.; Warfield, S.; Kikinis, R.; Barnes, P. D.; Zientara, G. P.; Jolesz, F. A.;

Tsuji, M. K.; Volpe, J. J. Quantitative magnetic resonance imaging of brain

development in premature and mature newborns. Ann-Neurol. 1998 Feb; 43(2):

224-35; ISSN: 0364-5134.

UNITED-STATES. Definition in the living premature infant of the anatomical

and temporal characteristics of development of critical brain structures is crucial

for insight into the time of greatest vulnerability of such brain structures. We used

three-dimensional magnetic resonance imaging (3D MRI) and image-processing

algorithms to quantitate total brain volume and total volumes of cerebral gray

matter (GM), unmyelinated white matter (WM), myelinated WM, and

cerebrospinal fluid (CSF) in 78 premature and mature newborns

(postconceptional age, 29-41 weeks). Total brain tissue volume was shown to

increase linearly at a rate of 22 ml/wk. Total GM showed a linear increase in

relative intracranial volume of approximately 1.4% or 15 ml in absolute volume

per week. The pronounced increase in total GM reflected primarily a fourfold

increase in cortical GM. Unmyelinated WM was found to be the most prominent

brain tissue class in the preterm infant younger than 36 weeks of

postconceptional age. Although minimal myelinated WM was present in the

preterm infant at 29 weeks, between 35 and 41 weeks an abrupt fivefold increase

in absolute volume of myelinated WM was documented. Extracerebral and

intraventricular CSF was readily quantitated by this technique and found to

change minimally. The application of 3D MRI and tissue segmentation to the

study of human infant brain from 29 to 41 weeks of postconceptional age has

provided new insights into cerebral cortical development and myelination and has

for the first time provided means of quantitative assessment in vivo of early

human brain development.

146. Iavorskii, A. B.; Kobrin, V. I.; Sologubov, E. G.; Sinel'nikova, A. N.; Nemkova, S. A.

[Changes in individual profiles of cerebral hemispheric asymmetry during

somatosensory stimulation due to wearing of G-suits by healthy adults and

children]. Izmenenie individual'nogo profilia mezhpolusharnoi asimmetrii mozga

pri somatosensornoi stimuliatsii nosheniem kosmicheskogo nagruzochnogo

kostiuma u zdorovykh vzroslykh i detei. Aviakosm-Ekolog-Med. 1997; 31(6):

18-23; ISSN: 0233-528X.

RUSSIA. Presented are results of the investigations of individual profiles of the

brain interhemispheric asymmetry (IPIHA) in healthy grown-ups and children

prior to, during, and immediately after somatosensory stimulation. The

somatosensory stimulation was performed by one-time wearing of space g-loading

suit PENGUIN and its modification ADELIE. IPIHA was studied by the main

functional asymmetries including motor hand asymmetry, sensory asymmetry of

the visual hemispheres, body mass center asymmetry (BMA) using a

computerized stabilimeter indirectly measuring the muscle tone of contralateral

extensor. Results demonstrate differences in IPIHA of grown-ups and children,

persons with right- and left-hand motor asymmetry. It was shown that peculiar

features of standing posture acquisition with and without visual control are

original IPIHA and age dependent. Initial stability was higher in grown-ups than

children and right-handed grown-ups and left-handed children. IPIHA and

stability of the vertical posture can be modified even during single somatosensory

stimulation. Unequal effects of the somatosensory stimulation on IPIHA in right-

and left-handed subjects of varying age dictate the necessity to allow for these

differences when assessing effects of the somatosensory stimulation in grown-ups

and developing criteria of effective therapy of patients with CNS pathology,

specifically, infantile cerebral paralysis.

147. Imaizumi, S.; Arai, S.; Sakurai, Y.; Uenohara, H.; Nishino, A. Regional cerebral blood

flow measured with 99mTc-HMPAO based on two-dimensional 133Xe study in

ischemic brain. Neurol-Med-Chir-Tokyo. 1996 Nov; 36(11): 775-81; discussion

781-2; ISSN: 0470-8105.

JAPAN. Two-dimensional regional cerebral blood flow (rCBF) was measured

using the xenon-133 inhalation method, and used to calibrate the rCBF measured

by single photon emission computed tomography (SPECT) in the non-affected

middle cerebral artery (MCA) area. The value of the rCBF in the target area could

then be measured by SPECT and compared between patients. Technetium-99m-

d,l-hexamethyl-propylene-amine-oxime and technetium-99m-

diethylenetriaminepenta-acetic acid-human serum albumin D were used to

measure rCBF and regional cerebral blood volume (rCBV), respectively, in the

ischemic area of 16 patients who underwent surgical revascularization in the

chronic stage. No significant increase in rCBF was obtained after the bypass

surgery. The delta rCBF and delta CBF/CBV ratio correlated well with the extent

of vascularization in the MCA area on postoperative angiograms. Patients with a

low CBF/CBV ratio on preoperative SPECT scans tended to show favorable

postoperative vascularization and rCBF in the MCA area. Since the angiographic

findings and the delta rCBF or delta CBF/CBV were correlated well, this simple

and non-invasive method could be used for the analysis of rCBF in a group of

patients.. 0; 0; 0.

148. Inoue, K.; Kawashima, R.; Satoh, K.; Kinomura, S.; Goto, R.; Koyama, M.; Sugiura,

M.; Ito, M.; Fukuda, H. PET study of pointing with visual feedback of moving

hands. J-Neurophysiol. 1998 Jan; 79(1): 117-25; ISSN: 0022-3077.

UNITED-STATES. This study was conducted to determine where in the human

brain visual feedback of hand movements is processed to allow accurate pointing.

Regional cerebral blood flow (rCBF) was measured with positron emission

tomography (PET) and H2 15O in nine normal volunteers while performing one

control and two reaching tasks. In all tasks, visual stimuli were presented on a

head mounted display (HMD). A target board was placed in front of the subjects

bearing six red light-emitting diodes (LEDs) aligned on a circle with a green LED at

its center. The center green LED and one of the six red LEDs, randomly selected,

were repeatedly switched on and off, alternatively. In the control task, subjects

were instructed to gaze at the lit LED. In the two reaching tasks, the reaching with

visual feedback (RwithF) task and the reaching without visual feedback

(RwithoutF) task, they had to point to the lit red LED with their right index

fingers. In the RwithF task, their right hands were visible on the HMD before

touching the target, whereas in the RwithoutF task, they were not visible. For

each subject, subtraction images of each reaching task minus the control and the

RwithF task minus the RwithoutF task were calculated after transformation of

PET images into the standard brain shape with an adjustable computerized brain

atlas. These subtraction rCBF images were then averaged among the subjects, and

significant changes of rCBF were identified. Significant increases in rCBF not only

in the RwithF task minus control image but also in the RwithF task minus the

RwithoutF task image were observed in the supramarginal cortex, the premotor

cortex and the posterior cingulate cortex of the left hemisphere, the caudate

nucleus and the thalamus of the right hemisphere, and the right cerebellum and

vermis. These results indicate that the supramarginal cortex, the premotor cortex,

and the posterior cingulate cortex of the left hemisphere and the cerebellum are

involved in integrating visual feedback of hand movements and execution of

accurate pointing.. 0.

149. Itoh, K.; Weis, S.; Mehraein, P.; Muller Hocker, J. Cytochrome c oxidase defects of

the human substantia nigra in normal aging. Neurobiol-Aging. 1996 Nov; 17(6):

843-8; ISSN: 0197-4580.

UNITED-STATES. Based on morphological, biochemical, and molecular biologic

analyses, degeneration of the dopaminergic nigrostriatal system has been reported

to occur with normal aging. In the present study, the substantia nigra of 36 human

brains with normal aging was investigated by means of morphometry and

immunohistochemistry. The anteromedial (Am), anterointermediolateral (Ail),

posteromedial (Pm), and posterolateral (Pl) nuclei of the substantia nigra were

analyzed using antibodies directed against the subunits II/III of cytochrome c

oxidase (COX), the complex IV of the respiratory chain. The numerical density of

melanin-positive neurons with COX defects was significantly increased in the

four investigated nuclei, namely Am, Ail, Pm, and Pl. These cells did not show

any histologic signs of degeneration. The numerical density of melanin-positive

neurons without COX defects was decreased with aging. The data of the present

study indicate that complex IV defects of neurons in the substantia nigra might be

one cause of neuronal dysfunction occurring during aging.. EC 1.9.3.1; 51-61-6.

150. Jacobs, A.; Neveling, M.; Horst, M.; Ghaemi, M.; Kessler, J.; Eichstaedt, H.; Rudolf,

J.; Model, P.; Bonner, H.; de Vivie, E. R.; Heiss, W. D. Alterations of

neuropsychological function and cerebral glucose metabolism after cardiac surgery

are not related only to intraoperative microembolic events. Stroke. 1998 Mar;

29(3): 660-7; ISSN: 0039-2499.

UNITED-STATES. BACKGROUND AND PURPOSE: High-intensity

transient signals (HITS) during cardiac surgery are capable of causing

encephalopathy and cognitive deficits. This study was undertaken to determine

whether intraoperative HITS cause alterations of neuropsychological function

(NPF) and/or cerebral glucose metabolism (CMRGlc), even in a low-risk patient

group, and whether induced changes are interrelated. METHODS: Eighteen

patients without signs of cerebrovascular disease underwent elective coronary

artery bypass grafting (CABG), and two of these additionally underwent valve

replacement in normothermia. Intraoperatively, HITS were recorded by means of

transcranial Doppler ultrasonography (TCD). Perioperatively, NPF and CMRGlc

were assessed using a standardized complex test battery and positron emission

tomography with 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET), respectively.

RESULTS: Intraoperatively, the number of HITS ranged from 90 to 1710 per

patient and hemisphere, more on the right side than on the left (P<.05). HITS

occurred primarily during cardiopulmonary bypass (71.3%) and, to a lesser

extent, during aortic manipulation (22.2%). Changes in global and regional

CMRGlc between first (one day preoperatively) and second (8 to 12 days

postoperatively) FDG-PET scans were mild. No correlations were found between

the number of HITS, age of patient, duration of cardiac ischemia or

cardiopulmonary bypass and the changes in CMRGlc. In patients with recorded

HITS and a postoperative decrease of regional CMRGlc (n=11), the maximal

decrease of rCMR Glc in each hemisphere below the individual global change of

CMRGlc correlated with the number of HITS (r= -0.46, P<.05). Limitations in

NPF occurred 8 to 12 days postoperatively, resolved within 3 months, and were

not found to be correlated to the absolute number of HITS or changes in

CMRGlc. CONCLUSIONS: HITS during cardiac surgery can cause alterations of

both NPF and CMRGlc, even in a low-risk patient group. However, the number

of HITS and changes in NPF and CMRGlc are not necessarily interrelated, which

indicates that (1) the location of brain damage related to HITS is more important

for the development of NPF than is the absolute number of HITS, and (2) factors

in addition to HITS might contribute to surgery-related brain damage.. 50-99-7.

151. Jahan, R.; Mischel, P. S.; Curran, J. G.; Peacock, W. J.; Shields, D. W.; Vinters, H. V.

Bilateral neuropathologic changes in a child with hemimegalencephaly. Pediatr-

Neurol. 1997 Nov; 17(4): 344-9; ISSN: 0887-8994.

UNITED-STATES. Evaluation of a 7-month-old girl with developmental delay

and intractable seizures revealed hemispheric asymmetry and an enlarged right

cerebral hemisphere. Because of a history of seizures refractory to medical

therapy, she was admitted for right hemispherectomy, but died of complications

of surgery. Postmortem brain examination revealed asymmetric enlargement of the

right cerebral hemisphere but no gross abnormalities in the left hemisphere.

Microscopic examination demonstrated bilateral neuropathologic changes

consistent with severe cortical dysplasia in the right cerebral hemisphere and mild

cortical dysplasia in the left. Although white matter abnormalities in the

unaffected hemisphere have been reported in hemimegalencephaly, bilateral

cortical abnormalities, not reported previously in patients with

hemimegalencephaly, may account for the varied clinical outcome with medical

therapy or after hemispherectomy.

152. Jennings, J. M.; McIntosh, A. R.; Kapur, S.; Tulving, E.; Houle, S. Cognitive

subtractions may not add up: the interaction between semantic processing and

response mode. Neuroimage. 1997 Apr; 5(3): 229-39; ISSN: 1053-8119.

UNITED-STATES. Determining the areas of brain activity associated with

cognitive processing has typically relied on the use of a subtraction paradigm,

which is based on the premise that the neural processes underlying behavior are

additive. If the additivity assumption is valid then brain regions associated with a

semantic processing task should be the same regardless of how participants make

a response. To investigate this proposition, participants underwent six PET

scans, in which they made semantic or letter word judgments, responding "yes" or

"no" in three different modes: mouse-clicking, spoken response, or silent thought.

Analyses showed an increase in regional cerebral blood flow associated with

semantic processing in the left inferior frontal cortex, anterior cingulate, and right

cerebellum for all three response conditions. However, there was a significant

interaction: the greatest increase was observed in the mouse-click condition and

the weakest change seen with silent thought. Moreover, other areas of the brain

were uniquely activated for each response mode. The results indicate that

different areas of the brain were recruited for semantic processing depending on

how participants had to organize their responses. Implications for the additivity

assumption and methods of analysis to be used in conjunction with the

subtraction technique are discussed.

153. Jeong, S. C.; Bae, J. C.; Hwang, S. H.; Kim, H. C.; Lee, B. C. Cerebral sparganosis

with intracerebral hemorrhage: a case report. Neurology. 1998 Feb; 50(2): 503-6;

ISSN: 0028-3878.

UNITED-STATES. We describe the clinical case and radiologic findings in a

woman with cerebral sparganosis in which intracerebral hemorrhage was the

presenting feature with hemiparesis and dysarthria. CT demonstrated high-

density lesions in the right frontoparietal area, suggesting a hematoma. With

conservative management, hemiparesis improved and follow-up CT revealed what

looked like a resolving hematoma. Two weeks later, she complained once again of

aggravated left hemiparesis and facial weakness. Diagnosis of sparganosis was

made on the basis of brain MRI and ELISA. Stereotactic surgery was performed,

and a live larva of sparganum was successfully removed.

154. Jitsufuchi, N.; Kudo, K.; Imamura, T.; Kimura, K.; Ikeda, N. Distribution of drugs in

various tissues in a brain dead man. Forensic-Sci-Int. 1997 Nov 10; 90(1-2): 103-

9; ISSN: 0379-0738.

IRELAND. We examined the distribution of drugs in a 49-year-old brain-dead

man. Our objective was to determine the possibility of diagnosing how and at

what point the patient became brain dead. The presence of mepivacaine,

pentazocine, lidocaine and thiamylal in various tissues, including seven regions of

the brain were confirmed, using gas chromatography/mass spectrometry. Tissue-

to-blood concentration ratios of mepivacaine, pentazocine and lidocaine in the

brain were higher than these ratios in other tissues, while ratios of thiamylal were

lower. Therefore, cerebral blood flow was likely to have ceased between the

administration of the former drugs and that of the latter drug, in agreement with

clinical records. Among seven regions of the brain, the ratios of the former three

drugs were high in occipital and parietal lobes, and were low in the cerebellum and

medulla oblongata. On the other hand, the ratios of the latter drug were high in the

cerebellum and the medulla oblongata. Therefore, cerebral blood flow presumably

ceased first in occipital and parietal lobes, and last in the cerebellum and the

medulla oblongata. Based on these results, assessment of concentrations of drugs

in human tissues, including various regions of brain is useful to determine the time

and progression of brain death.. 0; 0; 0; 137-58-6; 359-83-1; 77-27-0; 96-88-8.

155. Jokeit, H.; Seitz, R. J.; Markowitsch, H. J.; Neumann, N.; Witte, O. W.; Ebner, A.

Prefrontal asymmetric interictal glucose hypometabolism and cognitive

impairment in patients with temporal lobe epilepsy. Brain. 1997 Dec; 120( Pt

12): 2283-94; ISSN: 0006-8950.

ENGLAND. Depressions of regional cerebral metabolism beyond the

epileptogenic zone have been demonstrated in patients with intractable temporal

lobe epilepsy. However, their clinical relevance, and the causes of prefrontal

metabolic asymmetries are less well understood. We investigated 96 temporal lobe

epilepsy patients by FDG-PET and neuropsychological assessment who had a

corresponding unilateral temporal hypometabolism, left hemisphere speech

dominance, full scale IQ of > 70 and no extratemporal lesion in MRIs. The

regional glucose metabolism was determined in each patient in homologous regions

including prefrontal cortex, and normalized to whole brain metabolism. Regional

differences of > 10% were regarded as asymmetrical. Prefrontal metabolic

asymmetries were more frequent in patients with left temporal lobe epilepsy (21

left, six right) and a history of secondarily generalized seizures. A multivariate

analysis of variance revealed a main effect for prefrontal metabolic asymmetry on

neuropsychological 'frontal lobe measures', including verbal and performance

intelligence measures. Prefrontal metabolic asymmetry was not related to

'measures of episodic memory', presence of psychiatric symptoms or frontal

interictal epileptiform discharges. We conclude that prefrontal metabolic

asymmetry is associated with cognitive impairment. Patients with temporal lobe

epilepsy of the left speech dominant hemisphere and a history of secondarily

generalized seizures are at considerable risk of developing prefrontal metabolic

asymmetry.. 63503-12-8.

156. Jones, A. K.; Derbyshire, S. W. Reduced cortical responses to noxious heat in

patients with rheumatoid arthritis. Ann-Rheum-Dis. 1997 Oct; 56(10): 601-7;

ISSN: 0003-4967.

ENGLAND. OBJECTIVES: To test the hypothesis that patients with chronic

inflammatory pain develop adaptive cortical responses to noxious stimulation

characterised by reduced anterior cingulate responses. METHODS: Positron

emission tomography was used to measure changes in regional cerebral blood flow

(rCBF) in response to an acute experimental pain stimulus in six patients with

rheumatoid arthritis (RA) in comparison to six age and sex matched controls. A

standardised and reproducible non-painful and painful phasic heat stimulus was

delivered by a thermal probe to the back of the right hand during six two minute

periods during which time rCBF measurements were made. The effects of non-

painful heat were subtracted from those of painful heat to weight the analysis

towards the non-discriminatory or 'suffering' components of pain processing.

Significance maps of pain processing were generated and compared in each group

and contrasted with results obtained in a group of patients with atypical facial

pain (AFP) that have been previously published. RESULTS: The RA patients

showed remarkably damped cortical and subcortical responses to pain compared

with the control group. Significant differences between the two groups were

observed in the prefrontal (BA 10) and anterior cingulate (BA 24) and

cingulofrontal transition cortical (BA 32) areas. The reduced anterior cingulate

responses to standardised heat pain were compared with the increased cingulate

responses seen in patients with psychogenically maintained pain (AFP) who had

both lower pain tolerance and mood than the RA group. CONCLUSIONS: Major

cortical adaptive responses to standardised noxious heat can be measured and

contrasted in patients with different types of chronic pain. The different pattern

of cingulate and frontal cortical responses in the patients with inflammatory and

non-nociceptive pain suggest that different mechanisms are operating, possibly at

a thalamocortical level. Implications for treatment strategies for chronic pain are

discussed.

157. Jones, K. J.; Drengler, S. M.; Oblinger, M. M. Gonadal steroid regulation of growth-

associated protein GAP-43 mRNA expression in axotomized hamster facial motor

neurons. Neurochem-Res. 1997 Nov; 22(11): 1367-74; ISSN: 0364-3190.

UNITED-STATES. Treatment with testosterone propionate (TP) after nerve

injury is known to accelerate both the rate of axonal regeneration and functional

recovery from facial paralysis in the adult male hamster. Peripheral nerve injury is

also known to increase the expression of a 43 kilodalton growth-associated

protein (GAP-43). In the intact brain, GAP-43 expression is affected by gonadal

steroids. We thus postulated that steroidal modulation of GAP-43 gene

expression may be a component of the neurotrophic action of TP in regenerating

neurons. This issue was examined in hamster facial motor neurons (FMN) which

contain androgen receptors and which have been shown to respond to exogenous

steroids in a number of previous studies. Castrated adult male hamsters were

subjected to right facial nerve transection and treated with either TP via

subcutaneous hormone capsule implants, or left untreated (no hormone

replacement). At post-injury/treatment times of 0.25, 2, 4, 7, and 14 d, the brain

stem regions were harvested, cryostat sections were collected through the facial

motor nucleus, and in situ hybridization was done using a 33P-labeled GAP-43

cDNA probe. Quantitative analysis of the autoradiograms by computer assisted

grain counting revealed that axotomy produced a dramatic increase in GAP-43

mRNA levels in FMN by 2 d post-axotomy and that this increase remained

through 14 d post-injury in both the TP-treated and the untreated group. In the

nonhormone-treated group, there was a statistically significant dip in GAP-43

mRNA levels in FMN at 7 d post-operative, relative to 4 d post-operative levels.

TP-treatment prevented this transient decline in GAP-43 mRNA levels in

axotomized FMN.. 0; 0; 57-85-2.

158. Jueptner, M.; Ottinger, S.; Fellows, S. J.; Adamschewski, J.; Flerich, L.; Muller, S. P.;

Diener, H. C.; Thilmann, A. F.; Weiller, C. The relevance of sensory input for the

cerebellar control of movements. Neuroimage. 1997 Jan; 5(1): 41-8; ISSN: 1053-

8119.

UNITED-STATES. The performance of a motor task not only requires subjects

to plan, prepare, and initiate but also to monitor how a movement is performed.

We used positron emission tomography to examine to what extent the human

cerebellum is involved in controlling motor output or sensory input from

movements in normal subjects. In the first study, we compared the active

performance of a motor task (flexion and extension of the right elbow) to the

passive execution of the same movements. Passive movements were driven by a

motor with the arm fixed in a guide hinge. Active movements (compared to rest)

elicited increases of rCBF mainly in the ipsilateral neocerebellar hemisphere and

vermis of the posterior lobe. During passive movements, almost identical parts of

the cerebellar hemispheres and vermis were activated (compared to the rest

condition). The direct comparison of active and passive movement conditions

revealed a small activation of the neocerebellar hemisphere of the posterior lobe

and cerebellar nuclei ipsilateral to the movement. Approximately 90% of

cerebellar neuronal activity was related to sensory input. In the second study, we

compared the execution of a free selection joystick movement task to a condition

in which subjects simply imagined the movements. The execution of movements

(compared to rest) was associated with increases of rCBF in the ipsilateral

neocerebellar hemisphere and vermis of the posterior lobe. During movement

imagination, a small part of the ipsilateral cerebellar hemisphere and vermis of the

posterior lobe was activated (compared to rest). The increase of rCBF during

movement imagination accounted for only 20% of the signal seen during

movement execution. Our results indicate that the neocerebellum may be much

more concerned with sensory information processing than has been considered

previously.

159. Kaas, J. H. What comparative studies of neocortex tell us about the human brain.

Rev-Bras-Biol. 1996 Dec; 56 Su 1 Pt 2: 315-22; ISSN: 0034-7108.

BRAZIL. There are several ways in which comparative studies of brain

organization and function can be informative in attempts to understand the human

brain. Often investigators study a favorable and sometimes specialized species in

order to reveal features that may reflect general or widespread principles. The

example used here is that the cortical representation of the unique and highly

specialized receptor sheet of the nose of the star-nosed mole provides further

evidence that the receptor sheet instructs the development of cortex. Comparative

studies are also used to reconstruct the evolution of brain systems. As an

example, comparative studies suggest that the visual area MT in the upper

temporal lobe of primates evolved from a visual area along the border of V2. A

third and very important use of comparative studies is to provide another level of

evaluation of theories developed from a particular species. Since the brains of

different mammals are modifications of an ancestral plan, conclusions about brain

organization in any given species should be consistent with those for other

species, within the framework of evolutionary change. When current proposals

for how visual cortex is organized in rats and humans are considered from a

comparative point of view, key concepts are clearly challenged.

160. Kanaya, K.; Katsunuma, H.; Tabata, M.; Akiba, Y.; Umahara, T.; Takasaki, M.

[Deterrent factors in rehabilitation training following cerebral vascular disease--

comparison of elderly and non-elderly patients]. Nippon-Ronen-Igakkai-Zasshi.

1997 Aug; 34(8): 639-45; ISSN: 0300-9173.

JAPAN. The purpose of the present study was to clarify the deterrent factors

for rehabilitation training (rehab) of chronic cerebral vascular disease (CVD)

patients, and also to evaluate the influence of age on these factors. Sixty-five CVD

impatients with sequelae treated at the Cerebral Vascular Center of Nanasawa

Hospital were included in the study. Patients were classified into two groups

using the Barthel index score: good effect group (n = 21) or no effect group (n =

22). The following factors were compared between the two groups in order to

investigate which factor most affects the results of rehab: age, sex, the site of brain

damage, extent of motor paralysis, character (Type A character or not), aphasia,

hemispacial neglect, depression, and positive attitude toward training. A possible

association between depression, and the site of brain damage and Type A

character was investigated. Also, the difference in mood disorders was compared

between elderly and non-elderly stroke patients. In the elderly group, hemispacial

neglect, a negative attitude toward training, and depression all adversely affected

the outcome of the rehab. In the non-elderly group, aging, hemispacial neglect, and

a negative attitude toward training influenced the effect of the rehab, but there was

no correlation with depression. Depression was seen in 64% of the patients

(38/59). Of the 38 patients in a depressed state, 24 (63%) had right hemisphere

brain damage, 13 (34%) had left hemisphere brain damage, and 1 (3%) had brain

stem damage. Twenty-seven of the 38 depressed patients (71%) were Type A

character, significantly more than in the non-depressed group (92/21, 43%). In

addition, 14 of the 27 Type A patients were aged over 65 years (52%), which was

more than in the non-depression group (11/38, 29%).

161. Kareken, D. A.; Unverzagt, F.; Caldemeyer, K.; Farlow, M. R.; Hutchins, G. D.

Functional brain imaging in apraxia. Arch-Neurol. 1998 Jan; 55(1): 107-13; ISSN:

0003-9942.

UNITED-STATES. BACKGROUND: An extensive literature describes

structural lesions in apraxia, but few studies have used functional neuroimaging.

We used positron emission tomography (PET) to characterize relative cerebral

glucose metabolism in a 65-year-old, right-handed woman with progressive decline

in ability to manipulate objects, write, and articulate speech. OBJECTIVE: To

characterize functional brain organization in apraxia. DESIGN AND METHODS:

The patient underwent a neurological examination, neuropsychological testing,

magnetic resonance imaging, and fludeoxyglucose F 18 PET. The patient's

magnetic resonance image was coregistered to her PET image, which was

compared with the PET images of 7 right-handed, healthy controls. Hemispheric

regions of interest were normalized by calcrine cortex. RESULTS: Except for

apraxia and mild grip weakness, results of the neurological examination were

normal. There was ideomotor apraxia of both hands (command, imitation, and

object) and buccofacial apraxia. The patient could recognize meaningful gestures

performed by the examiner and discriminate between his accurate and awkward

pantomime. The magnetic resonance image showed moderate generalized atrophy

and mild ischemic changes. Positron emission tomographic scans showed

abnormal fludeoxyglucose F 18 uptake in the posterior frontal, supplementary

motor, and parietal regions, the left affected more than the right. Focal metabolic

deficit was present in the angular gyrus, an area hypothesized to store conceptual

knowledge of skilled movement. CONCLUSIONS: Greater parietal than frontal

physiological dysfunction and preserved gesture recognition are not consistent

with the theory that knowledge of limb praxis is stored in the dominant parietal

cortex. Gesture comprehension may be more diffusely distributed.. 0; 50-99-7;

63503-12-8.

162. Kashihara, K.; Shiro, Y.; Shohmori, T.; Nomura, A.; Hara, H. [A man with systemic

lupus erythematosus presenting with spastic paraplegia]. No-To-Shinkei. 1997

Oct; 49(10): 915-8; ISSN: 0006-8969.

JAPAN. We report a 38-year-old man systemic lupus erythematosus who

presented with an acute onset of paraplegia and urinary retention. The man had a

12-year history of nodular cutaneous mucinosis and arthralgia. In 1994, he was

admitted to our hospital with a sudden onset of weakness and numbness of the

right leg followed by an emergence of similar symptoms in the left leg. His elder

sister had died at 16 years of age after suffering from systemic lupus

erythematosus for 6 years. On examination, the patient had skin rash on his chest,

back, head, forehead, and extremities. The neurological examination revealed that

his tongue deviated to the right on protrusion. The muscle power was reduced to

2-3/5 in the right leg and to 4/5 in the left leg. The sensory disturbance was noted

in the lower extremities with predominant involvement of the right leg. Reflexes

were increased in the right biceps, triceps, both patellas, and Achilles tendons.

Babinski sign was noted bilaterally. Urinary retention and constipation were also

noted. The results of the blood cell count and hepatic and renal function tests

were normal. Serum levels of C-reactive protein and complements (C3, C4, CH50)

were also normal. Serological examinations showed increased anti-DNA antibody

(14 U/ml, [normal, < 6]). Antinuclear antibody was positive at a titer of 1:1380.

CSF study showed an increased protein concentration of 83 mg/dl and an IgG

level of 14 mg/dl with a normal number of cells. MR images revealed a T1-low,

T2-high signal lesion at the upper part of the left ventral medulla. MR images of

the brain and spinal cord were normal. The patient was diagnosed as having SLE.

High-dose intravenous methylprednisolone (1 g/day) pulse treatment that was

started 25 days after the onset of neurological symptoms, produced partial relief.

Our case presented with paraplegia with a focal lesion in the left upper ventral

part of the medulla on MR images. The incidence of male SLE is low, and

paraplegia is a rare complication of SLE. Thus, the medullary lesion in SLE

observed in our case appears to be rare. SLE should be considered as a cause of

acute onset paraplegia or myelopathy.

163. Kato, H.; Mashiyama, S.; Fukawa, O.; Sasaki, T.; Yamane, Y.; Asano, S. [A case of

thymic carcinoma with brain metastasis]. Kyobu-Geka. 1997 Nov; 50(12): 1059-

63; ISSN: 0021-5252.

JAPAN. A 43-year-old female with a thymic carcinoma spreading to the

extrathorac region is reported. She had received radiation and chemotherapy, after

that thymic carcinoma was extirpated. Five months later, the patient was noticed

to have a right side hemiparesis, following consciousness disturbance. CT and

MRI revealed a left thalamic mass with a heterogenous enhancement effect. The

tumor was diminished dramatically due to radiation. Metastasis of thymic

carcinoma to the central nervous system is discussed.

164. Kawahata, N.; Daitoh, N.; Shirai, F.; Hara, S. [Reduction in mean cerebral blood flow

measurements using 99mTc-ECD-SPECT during normal aging]. Kaku-Igaku. 1997

Oct; 34(10): 909-16; ISSN: 0022-7854.

JAPAN. Mean cerebral blood flow (mCBF) was measured by SPECT using the

99mTc-ECD-Patlak-Plot method in a selected group of 61 normal non-

hospitalized subjects aged 51 to 91 years. The mCBF values showed 48.4 +/- 4.7

ml/100 g/min in aged 50-59 years group, 49.9 +/- 5.9 ml/100 g/min in aged 60-69

years group, 46.4 +/- 6.5 ml/100 g/min in aged 70-79 group, 38.0 +/- 3.7 ml/100

g/min in aged 80-89 years group, 38.9 ml/100 g/min in aged 90-99 years group.

There was a statistically significant reduction of mCBF with advancing age (R = -

0.41; p = 0.001). Women have significantly higher mCBF values than men up to

aged 70 years group. In this study, there was no significant laterality in the mCBF

between right and left hemispheres in all decade groups. The history of

hypertension, alcohol consumption, and cigarette smoking failed to show

significant difference in the mCBF values. The present study shows that normal

aging is associated with mCBF reduction.. 0; 0; 0; 4371-52-2.

165. Keles, P.; Diyarbakirli, S.; Tan, M.; Tan, U. Facial asymmetry in right- and left-

handed men and women. Int-J-Neurosci. 1997 Oct; 91(3-4): 147-59; ISSN: 0020-

7454.

ENGLAND. A posteroanterior cephalometric radiographic study was performed

on the right- and left-handed men and women with normal occlusion. A

posteroanterior cephalometric radiography was conducted in these subjects.

Method of triangulation was used to measure various face areas. The surface areas

of these triangles were compared with their equivalents on the contralateral side.

Sex and its interactions with handedness and side were significant factors

influencing facial areas. Areas on the left were found to be significantly larger than

those on the right in right-handers. Left-handers were inconsistent in facial

asymmetry, but they tended to have larger facial areas on the right than the left.

Sex was especially significant for left-handers. It was suggested that an

asymmetric development in some brain regions may be responsible for the

development of asymmetric facial regions.

166. Kim, H. J.; Im, J. H.; Yang, S. O.; Moon, D. H.; Ryu, J. S.; Bong, J. K.; Nam, K. P.;

Cheon, J. H.; Lee, M. C.; Lee, H. K. Imaging and quantitation of dopamine

transporters with iodine-123-IPT in normal and Parkinson's disease subjects. J-

Nucl-Med. 1997 Nov; 38(11): 1703-11; ISSN: 0161-5505.

UNITED-STATES. Iodine-123-N-(3-iodopropene-2-yl)-2beta-carbomethoxy-

3beta-( 4-chlorophenyl) tropane (123I-IPT) is a new dopamine transporter ligand

that selectively binds the dopamine reuptake sites. Transporter concentrations

have been known to decrease in Parkinson's disease patients. The purpose of this

study was to evaluate the usefulness of IPT as an imaging agent for measuring

changes in transporter concentrations in Parkinson's disease. METHODS: IPT

labeled with 6.78 +/- 0.67 mCi 123I was injected intravenously as a bolus into

eight normal controls (mean age 41 +/- 12 yr) and 17 Parkinson's disease patients

(mean age 55 +/- 9 yr). Dynamic SPECT scans of the brain were then performed

for 5 min each over 120 min on a triple-headed gamma camera equipped with

medium-energy collimators. Regions of interest were drawn on the middle set of

the image at the level of the basal ganglia (BG) for each subject. Time-activity

curves were generated for the left BG, right BG and occipital cortex (OCC). The

empirical ratios between BG-OCC and OCC, which represent specific-to-

nonspecific binding ratios, were computed at various time points. The statistical

parameter k3/k4 was estimated by two methods: a variation of the graphic method

that derives the ratio of ligand distribution volumes (R[V]) and the area ratio

method (R[A]), in which the ratio is calculated from the areas under the specific

and nonspecific binding activity curves. RESULTS: The mean (BG-OCC)/OCC

ratio for normal controls (3.07 +/- 0.73) was significantly higher than that for

Parkinson's disease patients at 115 min (1.10 +/- 0.56) (p = 2.76 x 10[-5]). The

mean R(V) and R(A) for normal controls were 2.06 +/- 0.27 and 1.50 +/- 0.15,

respectively. The mean R(V) and R(A) for Parkinson's disease patients were 0.78

+/- 0.31 and 0.65 +/- 0.24, respectively. Both R(V) and R(A) for normal controls

were significantly higher than those for Parkinson's disease patients (p values for

R(V) and R(A) were 1.91 x 10(-8) and 3.46 x 10(-10), respectively). The R(V) has

linear relationships with both R(A) and (BG-OCC)/OCC ratio at 115 min. The

R(V) has a higher correlation (r = 0.99) with R(A) than it does with (BG-

OCC)/OCC (r = 0.93). CONCLUSION: The R(V), R(A) and (BG-OCC)/OCC for

Parkinson's disease patients were clearly separated from those of normal controls,

and they may be useful outcome measures for clinical diagnosis. The simplest

(BG-OCC)/OCC ratio, requiring a single late time point, could be useful in clinical

situations, whereas R(V) or R(A) is preferred when the dynamic data are

available. The findings suggest that 123I-IPT is a useful tracer for diagnosing

Parkinson's disease and studying dopamine reuptake sites.. 0; 0; 0; 0; 155509-52-

7; 51-61-6.

167. Kleinschmidt, A.; Nitschke, M. F.; Frahm, J. Somatotopy in the human motor cortex

hand area. A high-resolution functional MRI study. Eur-J-Neurosci. 1997 Oct;

9(10): 2178-86; ISSN: 0953-816X.

ENGLAND. Fine-scale somatotopic encoding in brain areas devoted to

sensorimotor processing has recently been questioned by functional neuroimaging

studies which suggested its absence within the hand area of the human primary

motor cortex. We re-examined this issue by addressing somatotopy both in terms

of functional segregation and of cortical response preference using oxygenation-

sensitive magnetic resonance imaging at high spatial resolution. In a first step,

spatial representations of self-paced isolated finger movements were mapped by

using motor rest as a control state. A subsequent experimental design studied the

predominance of individual finger movements by using contrasting finger

movements as the control task. While the first approach confirmed previous

reports of extensive overlap in spatial representations, the second approach

revealed foci of differential activation which displayed an orderly mediolateral

progression in accordance with the classical cortical motor homunculus. We

conclude that somatotopy within the hand area of the primary motor cortex does

not present as qualitative functional segregation but as quantitative predominance

of certain movement or digit representation embedded in an overall joint hand area.

168. Knecht, S.; Deppe, M.; Ebner, A.; Henningsen, H.; Huber, T.; Jokeit, H.; Ringelstein,

E. B. Noninvasive determination of language lateralization by functional

transcranial Doppler sonography: a comparison with the Wada test. Stroke. 1998

Jan; 29(1): 82-6; ISSN: 0039-2499.

UNITED-STATES. BACKGROUND AND PURPOSE: Functional transcranial

Doppler ultrasonography (fTCD) can assess event-related changes in cerebral

blood flow velocities and, by comparison between sides, can provide a measure of

hemispheric perfusional lateralization. It is easily applicable, insensitive to

movement artifacts, and can be used in patients with less than perfect

cooperation. In the present study we investigated the validity of fTCD in

determining the hemispheric dominance for language by direct comparison of

fTCD with intracarotid amobarbital anesthesia (Wada test). METHODS: fTCD

and the Wada test were performed in 19 patients evaluated for epilepsy surgery.

By the Wada test, 13 patients were classified as left-hemisphere dominant and 6

as right-hemisphere dominant for language. fTCD was based on the continuous

bilateral measurements of blood flow velocities in the middle cerebral arteries and

event-related averaging during a cued word generation task previously shown to

activate lateralized language areas in normal adults. RESULTS: In 4 patients fTCD

assessment was not possible because of lack of an acoustic temporal bone

window. In the remaining 15 candidates, determination of language dominance was

concordant with the Wada test in every case. Moreover, the correlation of the

lateralization measures from both procedures was highly significant (r=.92,

P<.0001). CONCLUSIONS: This strong correlation validates fTCD as a

noninvasive and practical tool for the determination of language lateralization that

can be applied for clinical and investigative purposes.. 0; 0; 57-43-2.

169. Knipst, I. N.; Cheremushkin, E. A.; Iakovenko, I. A. [The subsystems of the spatial-

temporal organization of cortical potentials and their role in EEG spatial

synchronization]. Podsistemy prostrantsvenno-vremennoi organizatsii

korkovykh potentsialov i ikh rol' v prostranstvennoi sinkhronizatsii EEG. Zh-

Vyssh-Nerv-Deiat-Im-I-P-Pavlova. 1997 Sep; 47(5): 812-27; ISSN: 0044-4677.

RUSSIA. Studying successive topograms of potentials made it possible to reveal

different types (subsystems) of the spatio-temporal organization of human and

animal cortical electrical activity, which covered significant cortical surface. The

dominance of the inversion of the sagittal potential gradient in the topograms of

the resting state or complicated relief forms in the active states co-existed with

oscillations of the mean level of topogram potentials, the contribution of which to

the spatial EEG synchronization changed depending on the functional state of the

brain. The role of the ratio between these subsystems was shown and the

influence of this ratio was demonstrated on the spatial synchronization of cortical

potentials in experiments with 11 rabbits (in the course of their adaptation to the

environment and learning) and examination of 50 healthy adult subjects (during

motor task performance and elaboration of verbal set). The spatial

synchronization of cortical potentials was found to have a complex structure,

which was determined by the ratio between the effects of subsystems of the

spatio-temporal organization of cortical potentials.

170. Kobayashi, T.; Takanashi, M.; Mori, H.; Suzuki, M.; Suda, K.; Takubo, H.; Mizuno,

Y. [A 85-year-old woman with one year history of convulsion, dementia, and

consciousness disturbance (clinical conference)]. No-To-Shinkei. 1997 Oct;

49(10): 953-61; ISSN: 0006-8969.

JAPAN. We report a 85-year-old woman who died after one year history of

convulsion, dementia, and consciousness disturbance. She was apparently well

until January 6, 1995 when she was 85 year old; on that evening, she suddenly

stated that some one was in her room and she became confused. A local MD gave

her diazepam and she fell into sleep. At 3 o'clock in the following morning, she

developed tonic-clonic convulsion in her right lower extremity which showed a

march to her right upper extremity and the left lower extremity. She was admitted

to our hospital. On admission, she was comatose with respiratory acidosis. She

was intubated and placed on a ventilator. She was treated with intravenous

phenytoin. She gradually gained consciousness and became alert. Respiration

became normal. Her MRI revealed ventricular dilatation, fronto-parietal cortical

atrophy, and a T1-low and T2-high signal intensity lesion in the left occipital

lobe. She was discharged for out patient follow-up on February 4, 1995. Since

then, she noted loss of memory and small step gait. A follow-up CT scan revealed

a mass lesion which showed a ring-shaped enhancement in the left occipital lobe

and was admitted again. On admission, she was alert but markedly demented. The

optic fundi was unremarkable, but she appeared to have right homonymous

hemianopsia. No motor weakness was noted. In Gd-DTPA enhanced MRI, the

above tumor showed a ring enhancement. The diagnosis of glioblastoma was

entertained, however, considering her age, she was treated with intravenous

glycerol and intramuscular steroid. She was discharged for out-patient follow-up

on July 15, 1995. Her gait disturbance had progressively become worse and she

developed nausea and vomiting and was admitted again on October 2, 1995. On

admission, she was somnolent and markedly demented. Brain stem responses

were retained normally. She was unable to stand or walk. Deep tendon reflexes

were slightly increased in the right upper extremity and the plantar response was

extensor on the right. Her hospital course was complicated by respiratory tract

infection and respiratory acidosis. She expired on November 2, 1995. The patient

was discussed in a neurological CPC and the chief discussant arrived at the

conclusion that she had a glioblastoma involving the left occipital lobe and the

adjacent areas. Post-mortem examination revealed an infiltrating tumor in the left

occipital lobe. On microscopic examination, the tumor was very cellular; nuclear

atypism was marked and tumor cells undergoing mitosis were seen. In some areas,

capillary proliferation was seen. Histologic characteristics were consistent with

glioblastoma.

171. Kopelman, M. D.; Stanhope, N.; Kingsley, D. Temporal and spatial context memory

in patients with focal frontal, temporal lobe, and diencephalic lesions.

Neuropsychologia. 1997 Dec; 35(12): 1533-45; ISSN: 0028-3932.

ENGLAND. Patients with focal frontal, temporal lobe, or diencephalic lesions

were investigated on measures of temporal (recency) and spatial (position)

context memory, after manipulating exposure times to match recognition memory

for targets (pictorial stimuli) as closely as possible. Patients with diencephalic

lesions from an alcoholic Korsakoff syndrome showed significant impairment on

the temporal context (recency) task, as did patients with frontal lesions

penetrating the dorsolateral frontal cortex, according to MRI (and PET) evidence.

Patients with temporal lobe lesions showed only a moderate (non-significant)

impairment on this task, and patients with medial frontal lesions, or large frontal

lesions not penetrating the dorsolateral cortical margins, performed as well as

healthy controls at this task. On the spatial context memory task, patients with

lesions in the temporal lobes showed significant impairment, and patients with

right temporal lesions performed significantly worse than patients with left

temporal lesions. Patients with diencephalic lesions showed only a modest (non-

significant) impairment on this task, and the frontal lobe group performed

normally. When a group of patients with temporal lobe lesions resulting from

herpes encephalitis were examined separately, an identical pattern of results was

obtained, the herpes group being significantly impaired on spatial memory and

showing a trend towards impairment for temporal context memory. There were

strong correlations between anterograde memory quotients and context memory

performance (despite the use of an exposure time titration procedure) and a weak

association with one frontal/executive task (card-sorting perseverations). It is

predicted that correlations between temporal context memory and

frontal/executive tasks will be greater in samples of patients all of whom have

frontal lesions invading the dorsolateral cortical margin.

172. Korkman, M.; von Wendt, L. Evidence of altered dominance in children with

congenital spastic hemiplegia. J-Int-Neuropsychol-Soc. 1995 May; 1(3): 261-70;

ISSN: 1355-6177.

ENGLAND. The study aimed at investigating lateralization effects and signs of

transfer and crowding in children with congenital lateralized brain damage with the

aid of a dichotic listening test, a chimeric test, and verbal and nonverbal

neuropsychological tests. Thirty-three children with spastic hemiplegia and 86

control children (age 5.0-12.0 yr) were assessed. Children with left-hemisphere

damage (n = 17) were found to have a pathological left-ear advantage for verbal

material, and children with right-hemisphere damage (n = 16) were found to have a

pathological right visual half-field advantage for visual material. Children with left-

hemisphere damage and a left-ear advantage on the dichotic test were also found to

have a right visual half-field advantage on the chimeric test, which was regarded as

a sign of reversed dominance. No verbal or nonverbal differences emerged between

the left-hemisphere and the right-hemisphere damage groups, nor did differences

emerge when the children were reclassified by considering children with left

hemisphere damage and signs of reversed dominance as having damage to the

nondominant hemisphere. It was concluded that although lateralized brain damage

may alter the dominance for verbal and visual functions, there is still considerable

inter-individual variability with respect to inter- and intrahemispheric neural

adjustment to damage. The dichotic and the chimeric tests did not indicate the

presence of brain damage accurately, but they indicated the lateralization of

damage in children with stated abnormality with a high degree (91.3%) of

accuracy.

173. Koyama, Y.; Ishiai, S.; Seki, K.; Nakayama, T. Distinct processes in line bisection

according to severity of left unilateral spatial neglect. Brain-Cogn. 1997 Nov;

35(2): 271-81; ISSN: 0278-2626.

UNITED-STATES. We investigated the line bisection performances in 24

patients with left unilateral spatial neglect. They bisected lines of two lengths in

three positions relative to the sagittal midplane of the body. The results showed

that in the mild or moderate neglect patients, length and spatial locations of the

lines affected the placement of the subjective midpoint. In the severe neglect

patients, however, length had little effect on their performances, and location of

the right endpoint in the egocentric space mainly determined the subjective

midpoint. The line bisection process of the severe neglect patients was not only

quantitatively but also qualitatively different from that of the mild or moderate

cases. Copyright 1997 Academic Press.

174. Krimer, L. S.; Herman, M. M.; Saunders, R. C.; Boyd, J. C.; Hyde, T. M.; Carter, J.

M.; Kleinman, J. E.; Weinberger, D. R. A qualitative and quantitative analysis of

the entorhinal cortex in schizophrenia. Cereb-Cortex. 1997 Dec; 7(8): 732-9;

ISSN: 1047-3211.

UNITED-STATES. The entorhinal cortex (ERC) has been implicated in

schizophrenia by a number of studies. There is anatomical observation of neuronal

heterotopias in the rostral ERC, which is consistent with a hypothesis of

neurodevelopmental abnormalities in this disease. In view of the significant

cytoarchitectonic variation of the ERC throughout its rostro-caudal extent, we

performed a detailed subareal analysis of the rostral two-thirds of the entorhinal

cortex (ERCr) in 14 postmortem schizophrenic brains and 14 matched controls

(mean ages of 48 and 47 respectively). This systematic evaluation included both a

qualitative microscopic analysis of morphogenetic anomalies that would be

consistent with neurodevelopmental pathology and quantitative measurements of

total neuronal number, average neuronal density, laminar volume and laminar

depth from the cortical surface in cytoarchitectonically matched subareas of

schizophrenic and control brains. Parcellation of the entire ERC on the basis of

cytoarchitectonic criteria identified five distinct regions, similar to those described

in the macaque, except that in the human brain three of the regions were further

divisible into two or three subareas, yielding nine distinct cellular compartments.

Five rostral areas, prorhinal (Pr), lateral (28L), intermediate rostral and caudal

(281r and 281c), and sulcal (28S), comprise the ERCr. Gross and microscopic

examination of these subdivisions throughout the ERCr failed to reveal laminar

disorganization in any of the schizophrenic brains. The brains also did not differ

significantly with respect to total neuronal number, total volume and neuronal

density per laminar and subareal subdivision, or laminar thickness per entorhinal

subarea. However, neuronal number and density were reduced by 12-18% in Pr

and 28L, suggesting that mild quantitative abnormalities may exist in the ERCr

and might possibly be revealed in a larger sample of schizophrenic brains. We

have failed to confirm previous reports of laminar disorganization in the ERCr in

brains of patients with schizophrenia; to the extent that this region is implicated

in schizophrenia, the structural changes are likely to consist of more subtle cellular

disturbances.

175. Krimer, L. S.; Hyde, T. M.; Herman, M. M.; Saunders, R. C. The entorhinal cortex:

an examination of cyto- and myeloarchitectonic organization in humans. Cereb-

Cortex. 1997 Dec; 7(8): 722-31; ISSN: 1047-3211.

UNITED-STATES. The entorhinal cortex (ERC) has been implicated in the

pathophysiology of Alzheimer's disease, schizophrenia and other disorders

affecting cognitive functions. While powerful anatomical and histochemical

methods (immunohistochemistry, in situ hybridization, etc.) may be applied

(although with limitations) to postmortem human brain, each analysis should

utilize a cytoarchitectonic approach to provide appropriate comparisons within

the subdivisions of the ERC. Accordingly, we describe here the normal cyto- and

myeloarchitecture of the human ERC as a prerequisite for the accompanying

study of this region in schizophrenia. Our parcellation of this cortex differs from

previous treatments in three ways. First, we adopted specific criteria of inclusion

to define each subdivision of the region. Although distinctive ERC features are

most prominent in the intermediate portion of this region, at least one of these

features was considered the minimum necessary criterion to include adjacent

tissue in the entorhinal area. Second, we used morphometric measurements

(neuronal size and density as well as subdivisional volume and laminar thickness)

to support our qualitative evaluation. Third, we have applied to the human ERC

the conventional cytoarchitectonic nomenclature of the entorhinal cortex used

previously in studies of non-human primates. This allows a more accurate

extrapolation of the available numerous experimental anatomical, physiological

and psychological data on this region to the human. As in the monkey, the five

main subareas were recognized in the human (prorhinal, lateral, intermediate,

sulcal and medial) but three required further subdivision (intermediate, sulcal and

medial). The morphometric results obtained suggested a progression of the human

entorhinal cortex from the peripheral to the central subareas, with the intermediate

subarea (281) as the most complete entorhinal subdivision. Compared with non-

human primates, the human ERC not only retains the basic periallocortical

organization but also demonstrates further evolution. Taken together with

available experimental data on the connectivity of this brain region, these results

provide an anatomical basis for evaluating the ERC in human behavior.

176. Kubota, Y.; Iwai, T.; Nakatani, K.; Sakai, N.; Hara, A. [Central nervous system

metastasis from non-functioning adrenocortical carcinoma: report of a case]. No-

Shinkei-Geka. 1997 Nov; 25(11): 1039-42; ISSN: 0301-2603.

JAPAN. We report a rare case of brain tumor metastasizing from an

adrenocortical carcinoma. A 47-year-old man was referred to our department on

September 21, 1995, with complaints of episodic loss of consciousness and severe

left motor weakness. There was a past history of left adrenalectomy performed in

the Department of Surgery of our hospital 9 months before. On admission,

computed tomography (CT) and magnetic resonance imaging (MRI) revealed two

well circumscribed masses in the right frontal lobe with peritumoral, marked brain

edema and metastasis to the lung. The brain tumor was successfully removed via

frontal craniotomy 4 days after admission. Histological examination of the tumor

specimen revealed metastatic anaplastic cell carcinoma, indicating metastasis from

an adrenocortical carcinoma. After chemotherapy with cisplatin, pepleomycin and

pirarubicin, he was discharged without neurological deficit. Two months

postoperatively, however, the patient received 50 Gy of telecobalt radiation

therapy to the whole brain because of recurrence. Three months after-wards, the

patient returned complaining of general fatigue. Chest CT scan revealed further

enlargement of the lung lesions. Despite repeated chemotherapy, the patient died

of lung metastases eight weeks later. Central nervous system metastasis from

adrenocortical carcinoma is exceedingly rare. To the best of our knowledge, only 5

cases have been reported. We report here another case of brain metastasis from

adrenocortical carcinoma possibly via lung metastasis, and review the pertinent

medical literature.

177. Kume, N.; Hayashida, K.; Cho, I. H.; Shimotsu, Y.; Nishioeda, Y.; Matsunaga, N.

Visualization of frontal postural hypoperfusion in patients with Takayasu

arteritis with upright 99Tcm-HMPAO brain SPET. Nucl-Med-Commun. 1997

Oct; 18(10): 943-50; ISSN: 0143-3636.

ENGLAND. Takayasu arteritis is a chronic inflammatory angiopathy involving

the cerebral arteries. We performed upright and supine 99Tcm-HMPAO brain

single photon emission tomography (SPET) to investigate the cerebral perfusion

pattern in eight patients with Takayasu arteritis, and we compared the results

with those acquired using 123I-IMP and acetazolamide in six patients. SPET

images were evaluated visually and semi-quantitatively. Hypoperfusion was

visually detected in all eight patients during the provocative upright test with

99Tcm-HMPAO, and in three of six tested using acetazolamide and 123I-IMP.

Semiquantitative analysis revealed that the mean cortical-to-cerebellar ratio in the

upright position was significantly changed compared to that in the supine

position in the right frontal area (from 0.86 +/- 0.07 to 0.91 +/- 0.09; P < 0.05).

Change was also seen in the left frontal area (from 0.85 +/- 0.08 to 0.91 +/- 0.08; P

< 0.05). No significant change was seen in other cortical areas with the upright

test or in any areas with the acetazolamide test. We postulate that reduced arterial

compliance may cause frontal postural hypoperfusion in patients with Takayasu

arteritis due to poor functioning of autoregulation and arterial stenosis or

occlusion. We conclude that the provocative upright test with 99Tcm-HMPAO

brain SPET can detect abnormal patterns of cerebral perfusion in patients with

Takayasu arteritis that might be missed by brain SPET using 123I-IMP and

acetazolamide.. 0; 0; 0; 51-43-4; 59-66-5.

178. Kusunose, M.; Fukuda, O.; Saito, T.; Takaku, A.; Endo, S. [Diffuse cerebral artery

vasospasm following total resection of posterior fossa meningioma: a case report].

No-Shinkei-Geka. 1997 Oct; 25(10): 953-7; ISSN: 0301-2603.

JAPAN. Diffuse cerebral artery vasospasm following brain tumor resection is a

rare complication. The authors reported a case of symptomatic diffuse cerebral

artery vasospasm of early phase following resection of a left posterior fossa

meningioma. A 50-year-old female patient was admitted to our hospital

complaining of headache. No neurological deficits were detected at the time of

admission. Computed tomography (CT) and magnetic resonance imaging (MRI)

showed a large mass in the left posterior fossa. Cerebral angiography

demonstrated mildly diffuse stenosis of the bilateral internal carotid artery. The

tumor was resected totally. CT after operation showed a small amount of

subarachnoid hematoma in the superior aspect of the cerebellum. Pathological

specimen of the tumor showed fibrous meningioma. One day after this radical

operation, the patient was found to have weakness in her left leg. Then she

developed left hemiparesis, weakness in the right leg and left homonymous

hemianopsia. MRI showed ischemic lesions in the bilateral parietal and the

occipital lobe. Angiography demonstrated diffuse severe vasospasm throughout

the whole cerebral artery. Ten days after the operation, angiographical findings

were improved. This case indicates that vasospasm may occur even after resection

of brain tumors which are localized outside the suprasellar area.

179. Lacquaniti, F.; Perani, D.; Guigon, E.; Bettinardi, V.; Carrozzo, M.; Grassi, F.;

Rossetti, Y.; Fazio, F. Visuomotor transformations for reaching to memorized

targets: a PET study. Neuroimage. 1997 Feb; 5(2): 129-46; ISSN: 1053-8119.

UNITED-STATES. Positron emission tomography (PET) was used to identify

cortical and subcortical regions involved in the control of reaching to visual targets.

Regional cerebral blood flow (rCBF) was measured in eight healthy subjects using

H2(15)O PET during the performance of three different tasks. All tasks required

central fixation while a 400-ms target was flashed every 5 s at a random location

around a virtual circle centered on the fixation target. Additional instructions

differed according to the task: (i) visual detection of the target without overt

responses; (ii) immediate pointing to the most recent target in the sequence, and

(iii) pointing to the previous target in the sequence. By design, the two motor

tasks differed in the cognitive processing required. In each trial of immediate

pointing, the spatial location of only the most recent target needed to be

processed. In each trial of pointing to the previous, instead, while the most recent

target was stored in memory for the movement of the next trial, the previous

target had to be retrieved from memory to direct the current movement. Limb

trajectories were comparable between the two motor tasks in terms of most

spatiotemporal parameters examined. Significant rCBF increases were identified

using analysis of covariance and t statistics. Compared with visual detection there

was activation of primary sensorimotor cortex, ventrolateral precentral gyrus,

inferior frontal gyrus in the opercular region, supramarginal gyrus, and middle

occipital gyrus, all these sites in the hemisphere (left) contralateral to the moving

limb, and cerebellar vermis, during both immediate pointing and pointing to the

previous. During immediate pointing there was additional activation of left inferior

parietal lobule close to the intraparietal sulcus, and when compared with pointing

to the previous, dorsolateral prefrontal cortex bilaterally. During pointing to the

previous, instead, there was additional activation of supplementary motor cortex,

anterior and midcingulate, and inferior occipital gyrus in the left hemisphere;

superior parietal lobule, supramarginal gyrus, and posterior hippocampus in the

right hemisphere; lingual gyri and cerebellar hemispheres bilaterally; anterior

thalamus; and pulvinar. The activation of two partially distinct cerebral networks

in these two motor tasks reflects the different nature of signal processing

involved. In particular, the specific activation of intraparietal sulcus and prefrontal

cortex in immediate pointing appears characteristic of a network for visuospatial

working memory. By contrast, the corticolimbic network engaged in pointing to

the previous could mediate spatial attention and the sequence of encoding,

recording, and decoding of spatial memories required by a dual task with two

competing targets.

180. Ladavas, E.; Berti, A.; Ruozzi, E.; Barboni, F. Neglect as a deficit determined by an

imbalance between multiple spatial representations. Exp-Brain-Res. 1997 Oct;

116(3): 493-500; ISSN: 0014-4819.

GERMANY. A previous study on neglect suggested that at least two hand

parameters are crucial in producing an amelioration of neglect: the hand (left or

right) and the spatial position of the hand (left or right). The improvement

observed in perceiving left targets when the left hand acts in the left space can be

due either to proprioceptive or to visual cuing. The stimulated left hand located in

the left space may act as a powerful visual cue for the enhancement of the left

visuo-spatial representation, in the same way as any other visual stimulus

presented in the periphery of the visual field. Alternatively, it may be that the

perceived hand location (due to the activation of the proprioceptive system) acts

as an attentional field able to enhance the representation of the left space. In order

to disentangle these two hypotheses, in the present study a naming task was

executed by a group of neglect patients and by a control group. The subjects had

to name all the objects depicted on a sheet of paper which were reflected on a

mirror that inverted right and left space. While doing the naming performance, the

subjects passively moved either the right or the left hand, in the left or right space.

Stimuli and hand were reflected in the mirror that inverted right and left space and

direct view of the stimuli and of the stimulated hand was prevented by a board.

The results show that patients were more accurate at naming stimuli reflected in

the left side of the mirror when the left hand was located and moved on the left

side. In this condition, however, the left hand was seen in the right side of the

mirror. It is therefore clear that the better performance was not due to visuo-

spatial cuing but to a proprioceptive cuing effect. The results are discussed in

terms of the relevance of personal and peripersonal spatial activation in the

modulation of extrapersonal visual neglect. The coactivation of different spatial

representations seems to be very influential on stimulus coding, thus confirming

that spatial awareness is strictly related to the joint activity of multiple brain

maps.

181. Laframboise, M.; Snyder, P. J.; Cohen, H. Cerebral hemispheric control of speech

during the intracarotid sodium amytal procedure: An acoustic exploration. Brain-

Lang. 1997 Nov 15; 60(2): 243-54; ISSN: 0093-934X.

UNITED-STATES. In this study we investigated lateralized control of speech

during the intracarotid amobarbital procedure. Vowel segments were extracted

from recordings made during two separate amobarbital procedures and involving

two patients. Subjects were right-handed, presented with focal left mesial

temporal epileptogenic foci. Age of onset of seizure disorders was 1.5 years for

one subject and 16 years for the other. Recorded pre- and postinjection speech

samples were digitized. Analyses were conducted on formants 1 and 2 (F1, F2)

measures to determine the extent of formant fluctuation in the time course of the

IAP. Preliminary results showed, for these two cases, that the left hemisphere is

involved in the control of both F1 and F2 and the right in the control of F2 only.

The data reveal the potential of coupling the IAP procedure and the acoustical

analysis of speech in the study of cerebral control of speech. Copyright 1997

Academic Press.. 0; 57-43-2.

182. Lane, R. D.; Reiman, E. M.; Bradley, M. M.; Lang, P. J.; Ahern, G. L.; Davidson, R.

J.; Schwartz, G. E. Neuroanatomical correlates of pleasant and unpleasant

emotion. Neuropsychologia. 1997 Nov; 35(11): 1437-44; ISSN: 0028-3932.

ENGLAND. Substantial evidence suggests that a key distinction in the

classification of human emotion is that between an appetitive motivational system

association with positive or pleasant emotion and an aversive motivational system

associated with negative or unpleasant emotion. To explore the neural substrates

of these two systems, 12 healthy women viewed sets of pictures previously

demonstrated to elicit pleasant, unpleasant and neutral emotion, while positron

emission tomographic (PET) measurements of regional cerebral blood flow were

obtained. Pleasant and unpleasant emotions were each distinguished from neutral

emotion conditions by significantly increased cerebral blood flow in the vicinity of

the medial prefrontal cortex (Brodmann's area 9), thalamus, hypothalamus and

midbrain (P < 0.005). Unpleasant was distinguished from neutral or pleasant

emotion by activation of the bilateral occipito-temporal cortex and cerebellum, and

left parahippocampal gyrus, hippocampus and amygdala (P < 0.005). Pleasant

was also distinguished from neutral but not unpleasant emotion by activation of

the head of the left caudate nucleus (P < 0.005). These findings are consistent

with those from other recent PET studies of human emotion and demonstrate that

there are both common and unique components of the neural networks mediating

pleasant and unpleasant emotion in healthy women.

183. Leask, S. J.; Crow, T. J. How far does the brain lateralize?: an unbiased method for

determining the optimum degree of hemispheric specialization. Neuropsychologia.

1997 Oct; 35(10): 1381-7; ISSN: 0028-3932.

ENGLAND. The relationship between measures (of size or function) on one side

of the brain, in relation to the difference between the two sides on that measure,

are important components of theories of hemispheric asymmetry. For example, it

has been concluded that increasing lateralization (e.g., of hand skill or planum

temporale area) occurs at the expense of the non-dominant hemisphere. Here it is

demonstrated that such relationships could merely be a necessary consequence of

relating components of a laterality index to the index (L - R)/(L + R) itself, or

indeed to L - R. An alternative approach (using random data to exemplify the null

hypothesis) is presented together with an application to data on hand skill from

12,782 11-year-olds in a cohort study. This demonstrates a symmetry hitherto

undocumented of maximal hand skill in left and right hands in left- and right-hand

writers respectively, the point of the maximum falling short of the population

mean for relative hand skill in either case. If degrees of laterality are what is

genetically determined, this suggests that selection is present for a function

(perhaps language) associated with a greater magnitude of lateralization than is

represented by hand skill.

184. Lechevalier, B. [Perception of musical sounds: contributions of positron emission

tomography]. La perception des sons musicaux: apports de la camera a positons.

Bull-Acad-Natl-Med. 1997 Jun; 181(6): 1191-9; discussion 1199-200; ISSN:

0001-4079.

FRANCE. The perception of music is not a single global process. It encompasses

the integration into conscience of various elements, such as sound pitch, tone,

rhythm and impression of familiarity. Thus, it may be subjected to cognitive

studies based on specific and complementary abilities of both cerebral

hemispheres in these tasks. A number of selected medical cases reported

previously had already suggested anatomic-clinical correlations for the perception

of the various components of musical sounds. The left hemisphere subserves

rhythm and pitch perception, the sense of familiarity and identification of a

musical piece. The right hemisphere plays a part in the perception of tone and

melodic line. Position emission tomographic studies in normal subjects have

corroborated these assumptions on hemispheric lateralization in musical

perception. In addition, they have demonstrated previously unsuspected facts,

such as the role of visual areas in pitch perception and the role of frontal cortex

and especially of Broca's area in the perception of rhythm.

185. Lee, J. T.; Hall, T. R.; Bateman, J. B. Optic nerve hypoplasia secondary to

intracranial teratoma. Am-J-Ophthalmol. 1997 Nov; 124(5): 705-6; ISSN: 0002-

9394.

UNITED-STATES. PURPOSE: To postulate a causal relation between optic

nerve hypoplasia and a suprasellar teratoma. METHOD: Case report. RESULTS:

A 6-month-old infant with suprasellar teratoma was visually inattentive and had

searching nystagmus. He had moderately severe, bilateral optic nerve hypoplasia

with the left eye being somewhat worse than the right eye. CONCLUSIONS:

Optic nerve hypoplasia is a major cause of impaired vision in children and rarely

has been attributed to an intracranial tumor. Our case, involving a patient with a

suprasellar teratoma and optic nerve hypoplasia, supports a causal relation

between the two.

186. Lejeune, H.; Maquet, P.; Bonnet, M.; Casini, L.; Ferrara, A.; Macar, F.; Pouthas, V.;

Timsit Berthier, M.; Vidal, F. The basic pattern of activation in motor and

sensory temporal tasks: positron emission tomography data. Neurosci-Lett. 1997

Oct 10; 235(1-2): 21-4; ISSN: 0304-3940.

IRELAND. Positron emission tomography (PET) data were obtained from

subjects performing a synchronization task (target duration 2700 ms). A

conjunction analysis was run to identify areas prominently activated both in this

task and in a temporal generalization task (target duration 700 ms) used

previously. The common pattern of activation included the right prefrontal,

inferior parietal and anterior cingulate cortex, the left putamen and the left

cerebellar hemisphere. These areas are assumed to play a major role in time

processing, in relation to attention and memory mechanisms.

187. Leskinen, S.; Pulkki, K.; Knuuti, J.; Kirvela, O.; Lehikoinen, P.; Nagren, K.;

Ruotsalainen, U.; Teras, M.; Wegelius, U.; Salminen, E. Transport of carbon-11-

methionine is enhanced by insulin. J-Nucl-Med. 1997 Dec; 38(12): 1967-70;

ISSN: 0161-5505.

UNITED-STATES. The anabolic effects of insulin are not restricted to

carbohydrate and lipid metabolism but also include protein metabolism. However,

the effects of insulin on protein metabolism have been difficult to demonstrate in

vivo. Amino acid transport is partly regulated by insulin according to the

experimental data. PET provides a way to measure fractional uptake rates of

amino acids. The purpose of this study was to measure the effect of insulin on

amino acid transport from the plasma to the human parotid glands. METHODS:

We compared the uptake of L-[methyl-11C]methionine ([11C]methionine) into

the parotid glands and cerebellum in seven healthy volunteers during the fasting

state and euglycemic insulin clamp technique (1 mU/kg per minute). RESULTS:

The fractional uptake rate of [11C]methionine was increased by 31% for the right

parotid gland (p = 0.003) and by 29% for the left parotid gland (p = 0.009) during

insulin clamp, while the increase was 19% for the cerebellum (p = 0.01). The

concentration of amino acids typical for the hormone-sensitive transport system

A was 11% lower during insulin infusion than in the fasting state.

CONCLUSION: The uptake of methionine into brain tissue does not seem to be

under major control by insulin, while the transport of methionine in the parotid

glands is stimulated by insulin. PET provides a sophisticated method to study the

transport system of amino acids in vivo.. 0; 11061-68-0; 58576-49-1; 7005-18-7.

188. Levy, L. M.; Henkin, R. I.; Hutter, A.; Lin, C. S.; Martins, D.; Schellinger, D.

Functional MRI of human olfaction. J-Comput-Assist-Tomogr. 1997 Nov; 21(6):

849-56; ISSN: 0363-8715.

UNITED-STATES. PURPOSE: Our goal was to use functional MRI (fMRI) to

measure brain activation in response to olfactory stimuli. METHOD: fMRI brain

scans were obtained in 17 normal subjects (9 men, 8 women) using-multislice

FLASH MRI in response to three olfactory stimuli (pyridine, menthone, amyl

acetate) in three coronal brain sections selected from anterior to posterior

temporal brain regions. Activation images were derived using correlation analysis,

and ratios of areas of brain activated to total brain areas were calculated.

RESULTS: Activation was present in each section in all subjects. Subjective

estimation of vapor intensity followed relative vapor pressure of stimuli

presented (pyridine > amyl acetate > menthone) and were similar for both men

and women. However, brain activation did not follow subjective responsiveness

order but rather pyridine > menthone > amyl acetate, a pattern demonstrated by

both men and women. Brain activation in women was consistently lower than in

men for all vapors in all brain sections, although regions of activation did not

differ. Activation occurred in regions previously recognized as associated with

olfactory stimulation, including orbitofrontal and entorhinal cortex; however,

extensive regions within frontal cortex including cingulate gyrus were also

activated. Brain regions activated to odors considered pleasant or unpleasant did

not differ. CONCLUSION: The techniques used in this study demonstrated that

brain activation to olfactory stimuli could be measured quantitatively such that

differences between groups of subjects (in this case men and women) could be

compared. Although localization of brain activation was not the major thrust of

this study, activation to olfactory stimuli was found not only in brain regions

previously associated with processing of olfactory information but also in several

other areas of frontal cortex, in cingulate gyrus, and in several components of the

limbic system. This is the first study in which activation in human brain

parenchyma of normal humans to olfactory stimuli has been quantitated by

fMRI.. 0; 0; 0; 110-86-1; 628-63-7; 89-80-5.

189. Lewis Jack, O. O.; Campbell, A. L.; Ridley, S.; Ocampo, C.; Brown, A.; Dennis, G.;

Wood, D. L.; Weir, R. Unilateral brain lesions and performance on Russell's

version of the Wechsler Memory Scale in an African American population. Int-J-

Neurosci. 1997 Oct; 91(3-4): 229-40; ISSN: 0020-7454.

ENGLAND. Studies of patients with unilateral lesions report hemisphere-

specific and locus-specific impairments on Russell's (1975) Revision of the

Wechsler Memory Scale (RWMS). In the current investigation "race-

homogeneous" and "race-comparative" paradigms provide the context in which the

generalizability of RWMS findings are examined in a population of African

Americans with unilateral lesions. The performances of brain-damaged patients

were impaired relative to normal controls on five of the six RWMS measures.

However, patients with left and right hemisphere damage in our sample did not

differ systematically on RWMS subtests. Likewise, among patients with lesions

confined to one of the quadrants in the brain, there were no quadrant group

differences in performance on RWMS subtests. But, right posteriors were

impaired relative to controls on immediate and delayed VR subtests. The relative

merits of the race-comparative and race-homogeneous paradigms are considered in

the context of these findings.

190. Lin, J. H.; Hou, J. W.; Teng, R. J.; Tien, H. F.; Lin, K. H. Jacobsen distal 11q deletion

syndrome with a myelodysplastic change of hemopoietic cells. Am-J-Med-Genet.

1998 Feb 3; 75(4): 341-4; ISSN: 0148-7299.

UNITED-STATES. We describe a male infant with unusual facial appearance,

relative pancytopenia, bilateral simian creases, and an accessory nipple.

Cytogenetic analysis showed deletion of the long arm of chromosome 11

[46,XY,del(11)(pter-->q23.2:)]. Bone-marrow study showed a myelodysplastic

change of hemopoietic cells compatible with peripheral blood findings. Pachygyria

of the temporal and frontal lobes was demonstrated by magnetic resonance image

(MRI) of the brain. We present our findings in order to contribute to the

information on 11q23 deletion.

191. Lin, K. C.; Cermak, S. A.; Kinsbourne, M.; Trombly, C. A. Effects of left-sided

movements on line bisection in unilateral neglect. J-Int-Neuropsychol-Soc. 1996

Sep; 2(5): 404-11; ISSN: 1355-6177.

ENGLAND. Thirteen patients with left neglect performed line bisection under

four conditions: no cue, visual cueing involving the report of a digit placed at the

left end of the line, circling the left-end digit, and digit circling plus tracing of the

line with the right index finger from its left end to its midpoint before bisection.

Digit circling plus finger tracing was unequivocally more effective in reducing left

neglect than digit circling alone, which was in turn more effective than visual

cueing; indeed, digit circling with tracing completely abolished the rightward

bisection bias. Thus continuously directing visuomotor control to the left side of

the line (even with the right hand) until bisection is performed reduces neglect

more than only requiring patients to attend to left-sided visual cues. The

facilitatory effects of the cueing procedures may reflect their differential efficacy

in constraining as well as attracting attention and action to the left part of the

target line. These findings have implications for neglect rehabilitation.

192. Litscher, G.; Schwarz, G.; Jobstmann, R.; Kehl, G.; Kleinert, R. Brain-stem auditory

evoked potential monitoring. The increase of the stimulus artifact in the

development of brain death: a biological phenomenon? Int-J-Neurosci. 1997 Sep;

91(1-2): 95-103; ISSN: 0020-7454.

ENGLAND. Brain-stem auditory evoked potentials (BAEPs) were recorded in

12 dead subjects (mean age, 72.6 +/- 14.8 years), 30.6 +/- 19.5 hours (range 9-70)

after abolished systemic circulation. Death was due to cardiac failure (n = 10),

intracerebral hemorrhage (n = 1) and larynx cancer (n = 1). The presence and

amplitude of the stimulus artifact were evaluated. The mean (+/- SD) amplitudes

of the stimulus artifact was 0.03 +/- 0.02 microV on the left side and 0.01 +/- 0.02

microV on the right side. These findings in accordance with previous studies on

comatose patients and brain dead subjects confirm that the increase of the

stimulus artifact in the development of brain death, in spite of stimulation with

alternating polarity, seems to reflect a biological phenomenon which is not found

in dead subjects after complete cessation of systemic circulation.

193. Liu, X. H.; Wang, P.; Barks, J. D. The non-competitive AMPA antagonist LY

300168 (GYKI 53655) attenuates AMPA-induced hippocampal injury in

neonatal rodents. Neurosci-Lett. 1997 Oct 10; 235(1-2): 93-7; ISSN: 0304-3940.

IRELAND. In contrast with the neuroprotective efficacy of competitive and non-

competitive N-methyl-D-aspartate (NMDA) antagonists versus NMDA

neurotoxicity, reported neuroprotective effects of non-NMDA antagonists in

limiting alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)

toxicity have been less robust. We tested the effect of the non-competitive

AMPA receptor antagonist LY 300168 (GYKI 53655; E. Lilly) (0.25 or 2.5 mg/kg

per dose i.p. x 3 doses vs. vehicle) on AMPA-induced excitotoxic injury in

postnatal day 7 (P7) rats. To assess specificity, we tested the effect of LY

300168 (2.5 mg/kg per dose x 3 doses) on NMDA-induced excitotoxic injury. P7

rats received right intrahippocampal injections of either (S)-AMPA (2.5 nmol, n =

67) or NMDA (12.5 nmol, n = 11). Injection of AMPA resulted in right

hippocampal atrophy with pyramidal cell loss. LY 300168 treatment produced

dose-dependent attenuation of AMPA-induced right hippocampal injury; based

on comparisons with left hippocampal volumes, 2.5 nmol AMPA resulted in 42

+/- 3% (mean +/- SEM) right hippocampal volume loss in controls, but only 10

+/- 5% after LY 300168 2.5 mg/kg per dose (P < 0.001; ANOVA). LY 300168

had no effect on NMDA-induced hippocampal injury. The data support the

hypothesis that drugs that allosterically regulate AMPA receptor activity can

modulate the response of immature brain to AMPA-mediated injury.. 0; 0;

146908-67-0; 6384-92-5; 77521-29-0.

194. Lohr, J. B.; Caligiuri, M. P. Lateralized hemispheric dysfunction in the major

psychotic disorders: historical perspectives and findings from a study of motor

asymmetry in older patients. Schizophr-Res. 1997 Oct 30; 27(2-3): 191-8; ISSN:

0920-9964.

NETHERLANDS. Differences in functioning between the two cerebral

hemispheres have been reported for more than a century. In recent decades, issues

related to lateralized dysfunction have been raised in psychiatric illnesses such as

schizophrenia and bipolar disorder. In particular, evidence suggests that

schizophrenia may be particularly associated with left hemisphere dysfunction

and bipolar disorder with right hemisphere dysfunction. We discuss these issues,

along with a conceptual framework for integrating hypotheses about the

relationship between the major psychotic illnesses based on a two-dimensional

continuum. We also present new findings from our study of motor asymmetry in

older patients with psychosis that support this framework. Our results indicate

that schizophrenia may be associated with left hemisphere pathology to a greater

extent than right, whereas the reverse may occur in bipolar disorder.

195. Longmore, J.; Shaw, D.; Smith, D.; Hopkins, R.; McAllister, G.; Pickard, J. D.;

Sirinathsinghji, D. J.; Butler, A. J.; Hill, R. G. Differential distribution of 5HT1D-

and 5HT1B-immunoreactivity within the human trigemino-cerebrovascular

system: implications for the discovery of new antimigraine drugs. Cephalalgia.

1997 Dec; 17(8): 833-42; ISSN: 0333-1024.

NORWAY. Sumatriptan, a 5HT1B/1D-receptor agonist, is clinically effective as

an antimigraine agent. Its therapeutic action may result partly from

vasoconstriction of excessively dilated cranial blood vessels (a 5HT1B-receptor

mediated response). The antimigraine activity of sumatriptan may also result from

inhibition of the release of vasoactive neuropeptides from trigeminal sensory

fibres within the meninges. The identity of the 5HT1B/1D-receptor subtype

mediating this effect is unknown. Using 5HT1D- and 5HT1B-receptor-specific

antibodies we have demonstrated a differential distribution of these receptor

subtypes within the human trigemino-cerebrovascular system. Only 5HT1B-

receptor protein was detected on dural arteries. In contrast, only 5HT1D-receptor

protein was detected on trigeminal sensory neurones including peripheral and

central projections to dural blood vessels and to the medulla. Within the medulla

5HT1D-receptor protein was confined to discrete areas associated with the

trigeminal sensory system. These findings have important implications for the

design of new antimigraine drugs.. 50-67-9.

196. Lucey, J. V.; Costa, D. C.; Adshead, G.; Deahl, M.; Busatto, G.; Gacinovic, S.;

Travis, M.; Pilowsky, L.; Ell, P. J.; Marks, I. M.; Kerwin, R. W. Brain blood flow

in anxiety disorders. OCD, panic disorder with agoraphobia, and post-traumatic

stress disorder on 99mTcHMPAO single photon emission tomography (SPET).

Br-J-Psychiatry. 1997 Oct; 171: 346-50; ISSN: 0007-1250.

ENGLAND. BACKGROUND: We compared regional cerebral blood flow

(rCBF) in three groups of patients with DSM-III-R anxiety disorders.

METHOD: Fifteen patients with obsessive -compulsive disorder (OCD), 15 with

panic disorder with agoraphobia (PA), and 16 with post-traumatic stress disorder

(PTSD) and a similar group of healthy controls were assessed on brain-dedicated

high-resolution SPET. RESULTS: MANOVA revealed significant rCBF

differences between diagnostic groups (F = 4.4; d.f. = 3, 57; P = 0.007) and

between cerebral regions (F = 6.4; d.f. = 1, 57; P = 0.01) in OCD and PTSD

compared with PA and healthy controls, limited to bilateral superior frontal

cortices and right caudate nuclei. Whole brain blood flow correlated positively

with anxiety (r = 0.24, n = 46, P = 0.05). Beck depression scores correlated

significantly negatively with left caudate rCBF (r = -0.24, n = 46, P = 0.05) and

right caudate rCBF (r = -0.31, n = 46, P = 0.02). PTSD syndrome severity

correlated significantly negatively with the left caudate (r = -0.49, n = 16, P =

0.03) and with right caudate rCBF (r = -0.7, n = 16, P = 0.001). CONCLUSIONS:

Functional rCBF differences in anxiety disorders could relate to repetitive,

intrusive, distressing mental activity, prominent in both OCD and PTSD.. 0; 0.

197. Luh, K. E.; Wagner, D. A. Cerebral asymmetries in processing strategies for letter and

symbol trigrams. Brain-Lang. 1997 Dec; 60(3): 464-88; ISSN: 0093-934X.

UNITED-STATES. Several studies have shown that laterally presented

consonant-vowel-consonant (CVC) strings produce both superior performance,

and a more wholistic processing strategy in the right visual field/left hemisphere

(RVF/LHEM), and a more sequential strategy in the inferior left visual field

(LVF). To determine whether these strategies are applied to other types of

trigrams subjects (n = 30) were asked to identify consonant and symbol trigrams

briefly projected unilaterally to the LVF or RVF, or bilaterally (the same trigram

in both fields--BVF). A second group of subjects (n = 30) first practiced

pronouncing consonant trigrams and then viewed them tachistoscopically. Both

tasks yield RVF advantages. Symbols are processed more wholistically in the

LVF, more sequentially in the RVF and in an intermediate pattern when presented

bilaterally. In contrast, subjects seem to chunk letters as bigrams, and do so

equally well in all fields, and visual field differences in strategies emerge for

consonants only when they are pronounced. Pronounceability of consonant

trigrams, assessed with ratings and vocal reaction times, was predicted by

orthographic regularity. Since the RHEM has limited phonetic skills, but it, like

the LHEM, is privy to information on orthographic regularity, the error pattern

on consonant strings indicates non-phonetic processing, whereas the RVF

wholistic strategy for consonant-vowel-consonant strings appears to reflect

phonetic processing.

198. Lyden, P. D.; Lonzo, L. M.; Nunez, S. Y.; Dockstader, T.; Mathieu Costello, O.;

Zivin, J. A. Effect of ischemic cerebral volume changes on behavior. Behav-Brain-

Res. 1997 Aug; 87(1): 59-67; ISSN: 0166-4328.

NETHERLANDS. Ischemia causes long-term effects on brain volume and

neurologic function but the relationship between the two is poorly characterized.

We studied the relationships between brain volume and three measures of rodent

behavior after cerebral ischemia was induced by injecting several thousand

microspheres into the internal carotid arteries of rats. Forty eight hours later, each

subject was rated using a global neurologic rating scale. Several weeks later, the

subjects were tested for open field activity and visual spatial learning. Post-

mortem we measured the volume of the cerebral hemispheres and estimated the

volume densities of cortex, white matter, hippocampus, basal ganglia, thalamus,

ventricle, and visible infarction. Ischemia caused significant impairment, as

measured by the global rating scale; the probability of an abnormal rating was

correlated with the number of microspheres trapped in the brains. Visual spatial

learning was significantly impaired by ischemia, but this deficit was independent

of the count of microspheres, whether the subject was abnormal at 48 h, and

whether the left or right hemisphere was embolized. Cerebral hemisphere volume

was reduced from 430 mm3 to 376 mm3 (P < 0.05). The cortex was reduced from

22 to 19% of cerebrum (P < 0.05) and the white matter compartment was reduced

to similar degree. The lesion volume was 6% of cerebrum, comparable to that seen

with other ischemia methods. The global outcome rating was significantly related

to total cerebral volume, but not to volume changes in any single compartment.

On the other hand, visual spatial learning was significantly influenced by volume

changes in the cortex and white matter, but not by the topography of the visible

infarctions. Open field activity was not altered by infarction. Our data suggests

that the total volume of brain tissue lost to infarction may partially determine

global neurological rating independently of the topography of the volume loss.

Integrative functions such as learning may depend more on the integrity of

specific compartments and less on the total volume of intact brain. The volume of

visible cystic infarction was not related to long term behavioral outcome. These

results should be confirmed using another method of inducing ischemia.. 0.

199. Maas, L. C.; Lukas, S. E.; Kaufman, M. J.; Weiss, R. D.; Daniels, S. L.; Rogers, V.

W.; Kukes, T. J.; Renshaw, P. F. Functional magnetic resonance imaging of human

brain activation during cue-induced cocaine craving. Am-J-Psychiatry. 1998 Jan;

155(1): 124-6; ISSN: 0002-953X.

UNITED-STATES. OBJECTIVE: Functional magnetic resonance imaging (MRI)

was used to test whether brain activation was detectable in regions previously

associated with cocaine cue-induced craving. METHOD: Blood oxygenation level

dependent (BOLD) functional activation was measured during presentation of

audiovisual stimuli containing alternating intervals of drug-related and neutral

scenes to six male subjects with a history of crack cocaine use and six male

comparison subjects. RESULTS: Significant activation was detected in the

anterior cingulate and left dorsolateral prefrontal cortex in the cocaine-using group.

In addition, a correlation between self-reported levels of craving and activation in

these regions was found. CONCLUSIONS: These results suggest that functional

MRI may be a useful tool to study the neurobiological basis of cue-induced

craving.. 0; 7782-44-7.

200. MacLeod, A. K.; Buckner, R. L.; Miezin, F. M.; Petersen, S. E.; Raichle, M. E. Right

anterior prefrontal cortex activation during semantic monitoring and working

memory. Neuroimage. 1998 Jan; 7(1): 41-8; ISSN: 1053-8119.

UNITED-STATES. Areas of the adult human brain used for semantic monitoring

were identified using positron emission tomography. For a series of tasks,

subjects viewed a list of familiar English nouns and monitored the words for

names of dangerous animals. The monitoring task used here also contained an

instruction to keep track of the number or percentage of targets for report after

the scan. Surface characteristics of the tasks such as stimulus rate, number of

targets, and whether subjects were asked to count or estimate the number of

targets were varied across multiple conditions within and between subjects. A

passive word viewing condition was used as the control in all subjects. Reliable

activations were identified in anterior and dorsal right prefrontal cortex [Brodmann

areas (BA) 9 and 10] and left extrastriate cortex. The right prefrontal cortical

locations are similar to areas that have been activated during many episodic

memory tasks. This surprising finding led to a thorough review of the literature

for examples of other activations within 16-mm vector distance of this right

prefrontal area. Activations in the vicinity of right BA10 due to episodic memory

retrieval, to various forms of working memory, and to miscellaneous tasks were

found. The right prefrontal activations in the current experiment and the additional

working memory and miscellaneous tasks demonstrate that, although right BA10

is routinely activated by episodic retrieval tasks, it is not uniquely activated by

episodic retrieval tasks.

201. MacLusky, N. J.; Bowlby, D. A.; Brown, T. J.; Peterson, R. E.; Hochberg, R. B. Sex

and the developing brain: suppression of neuronal estrogen sensitivity by

developmental androgen exposure. Neurochem-Res. 1997 Nov; 22(11): 1395-414;

ISSN: 0364-3190.

UNITED-STATES. The developmental effects of androgen play a central role in

sexual differentiation of the mammalian central nervous system. The cellular

mechanisms responsible for mediating these effects remain incompletely

understood. A considerable amount of evidence has accumulated indicating that

one of the earliest detectable events in the mechanism of sexual differentiation is a

selective and permanent reduction in estrogen receptor concentrations in specific

regions of the brain. Using quantitative autoradiographic methods, it has been

possible to precisely map the regional distribution of estrogen receptors in the

brains of male and female rats, as well as to study the development of sexual

dimorphisms in receptor distribution. Despite previous data suggesting that the

left and right sides of the brain may be differentially responsive to early androgen

exposure, there is no significant right-left asymmetry in estrogen receptor

distribution, in either sex. Significant sex differences in receptor density are,

however, observed in several regions of the preoptic area, the bed nucleus of the

stria terminalis and the ventromedial nucleus of the hypothalamus, particularly in

its most rostral and caudal aspects. In the periventricular preoptic area of the

female, highest estrogen receptor density occurs in the anteroventral

periventricular region: binding in this region is reduced by approximately 50% in

the male, as compared to the female. These data are consistent with the

hypothesis that androgen-induced defeminization of feminine behavioral and

neuroendocrine responses to estrogen may involve selective reductions in the

estrogen sensitivity of critical components of the neural circuitry regulating these

responses, mediated in part through a reduction in estrogen receptor

biosynthesis.. 0; 0.

202. Madden, D. J.; Turkington, T. G.; Coleman, R. E.; Provenzale, J. M.; DeGrado, T.

R.; Hoffman, J. M. Adult age differences in regional cerebral blood flow during

visual world identification: evidence from H215O PET. Neuroimage. 1996 Apr;

3(2): 127-42; ISSN: 1053-8119.

UNITED-STATES. We used H215O PET to investigate adult age differences in

regional cerebral blood flow (rCBF) during the performance of a visual word

identification task. The study participants were 20 healthy, right-handed men: 10

young adults between 18 and 27 years of age, and 10 older adults between 63 and

75 years of age. The word identification task comprised six blocks of test trials

representing four task conditions; subjects responded manually. The task

conditions varied with regard to whether semantic retrieval was required (e.g.,

word/nonword discrimination vs simple response to each stimulus) and with

regard to the difficulty of visual encoding (e.g., words presented normally vs

words with asterisks inserted between adjacent letters). Each subject performed

all six trial blocks, concurrently with each of six H215O PET scans. Analyses of

quantitative CBF data obtained from the arterial time-activity curve demonstrated

a significant age-related decline in global CBF rate. Analyses of the changes in

rCBF between task conditions indicated that retrieval of semantic information

sufficient to distinguish words from nonwords is mediated by a ventral

occipitotemporal cortical pathway. Specific areas within this pathway were also

associated with visual encoding processes. Several rCBF activations were

significantly greater for young adults than for older adults, indicating an age-

related decline in processing efficiency within this ventral occipitotemporal

pathway. Although the performance data demonstrated a greater age-related

slowing for visual encoding than for semantic retrieval, these age-related

performance changes were not associated with corresponding changes in rCBF

activation.

203. Maeda, T.; Hashizume, K.; Kunimoto, M.; Tanaka, T.; Yonemasu, Y. [Experimental

bilateral focus model of complex partial seizure: clinical, electrophysiological and

pathological studies]. No-To-Shinkei. 1997 Sep; 49(9): 813-8; ISSN: 0006-8969.

JAPAN. Stereotactic surgery was performed in Wistar rats and stainless steel

injection chemitrode were inserted in bilateral amygdala (AM). Stainless steel

screws were placed on the dura over bilateral motor cortex (Cx). One week after

the surgery, rats were placed in the recording chamber. Kainic acid (KA) injection

was performed into the left AM and focal AM seizure status was induced.

Seizures evolved into limbic seizure status during 3 days. Seven days after the

first KA injection, KA was injected into the right AM. The limbic seizure status

was elicited again, however, these seizures subsided within 3 days. About 3 week

after the first KA injection, spontaneous limbic seizures developed. Three ictal

EEG patterns were seen (1) Bilateral independent seizures, (2) Synchronous ictal

discharge over the bilateral AM, and (3) Switch of lateralized ictal activity from

one to the other AM. The histological study demonstrated bilateral hippocampal

cell loss and hippocampal atrophy. These changes are very similar to those

observed in human intractable complex partial seizures with bilateral mesial

temporal focus. The result suggests that this model will be a good tool in order to

resolve intractability of complex partial seizure in patients with bilateral temporal

focus.. 487-79-6.

204. Magga, J.; Vuolteenaho, O.; Marttila, M.; Ruskoaho, H. Endothelin-1 is involved in

stretch-induced early activation of B-type natriuretic peptide gene expression in

atrial but not in ventricular myocytes: acute effects of mixed ET(A)/ET(B) and

AT1 receptor antagonists in vivo and in vitro. Circulation. 1997 Nov 4; 96(9):

3053-62; ISSN: 0009-7322.

UNITED-STATES. BACKGROUND: The precise role of paracrine and

autocrine factors in mechanical load-induced activation of cardiac gene expression

is unknown. Here we report the effects of endothelin-1 (ET-1) and angiotensin II

(Ang II) receptor antagonism on acute pressure overload-induced activation of

cardiac B-type natriuretic peptide (BNP) gene expression in spontaneously

hypertensive rats (SHRs) in vivo and on mechanical stretch-induced increase in

atrial BNP gene expression in vitro. METHODS AND RESULTS: Acute

pressure overload produced in conscious SHRs by infusion of arginine8-

vasopressin (0.05 microg x kg(-1) x min(-1)) for 2 hours resulted in an increase in

BNP mRNA levels in the left ventricle as well as in the atrium. Bolus injections of

bosentan (mixed ET(A)/ET(B) receptor antagonist, 10 mg/kg I.V.) but not losartan

(AT1 receptor antagonist, 10 mg/kg I.V.) blocked the increase of the BNP mRNA

levels produced by pressure overload in the left atria, whereas the elevation of

BNP mRNA levels was similar (a 1.9-fold increase) in the left ventricles of

vehicle-, losartan-, and bosentan-infused SHRs. In an isolated perfused rat heart

preparation, infusion of bosentan (1 micromol/L) for 2 hours inhibited the

mechanical stretch-induced increase in BNP mRNA levels in the right atria,

whereas an AT1 receptor antagonist, CV-11974 (10 nmol/L), had no effect.

CONCLUSIONS: The findings of the present study demonstrate that Ang II and

ET-1 are not obligatorily required for stretch to trigger the increased BNP gene

expression in ventricular myocytes in vivo. In contrast, mechanical load on the

atrial myocytes did initiate an ET-1-dependent expression of BNP gene showing

that endogenous ET-1 production differentially regulates BNP gene expression in

atrial and ventricular myocytes.. 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 114471-18-0; 114798-

26-4; 139481-59-7; 147536-97-8.

205. Makino, S.; Chikazawa, H.; Yorimitsu, A.; Suehiro, T.; Hashimoto, K.; Ohashi, Y.;

Morioka, M.; Sasano, H. A rare case of Cushing's syndrome due to bilateral

adrenocortical adenomas. Endocr-J. 1997 Aug; 44(4): 533-40; ISSN: 0918-8959.

JAPAN. We report a rare case of Cushing's syndrome due to bilateral

adrenocortical adenomas in a 45-year-old female. She suffered from diabetes

mellitus and hypertension for a decade, but her appearance was not Cushingoid.

The plasma cortisol level in the morning was at the upper limit of the normal

range, but did not show a diurnal rhythm or was suppressed by 1 mg of

dexamethasone. The plasma level of ACTH was undetectable, and it failed to

respond to human CRH (hCRH). Plasma cortisol responded well to synthetic

ACTH. The urinary 17-OHCS level was high, and was not suppressed by 4 mg of

dexamethasone. While these findings were consistent with a diagnosis of

adrenocortical adenoma, computed tomography showed several nodules in both

adrenal glands that suggested the presence of huge nodular adrenocortical

hyperplasia or bilateral adrenocortical adenomas. Bilateral adrenalectomy

demonstrated the presence of three adenomas, two in the right and one in the left

adrenal. Analysis of the extract from each adenoma revealed that two of the three

produced an excess amount of cortisol. Magnetic resonance imaging (MRI) of the

brain suggested the presence of pituitary adenoma. Prior to adrenalectomy, TSH,

GH or LH showed a low response to TRH, GHRH or LHRH, respectively. Since

normal responses were restored after bilateral adrenalectomy, these abnormalities

were attributed to hypercortisolemia.. 50-02-2; 50-23-7; 9002-60-2.

206. Makris, N.; Worth, A. J.; Sorensen, A. G.; Papadimitriou, G. M.; Wu, O.; Reese, T.

G.; Wedeen, V. J.; Davis, T. L.; Stakes, J. W.; Caviness, V. S.; Kaplan, E.; Rosen,

B. R.; Pandya, D. N.; Kennedy, D. N. Morphometry of in vivo human white

matter association pathways with diffusion-weighted magnetic resonance imaging.

Ann-Neurol. 1997 Dec; 42(6): 951-62; ISSN: 0364-5134.

UNITED-STATES. The precise characterization of cortical connectivity is

important for the understanding of brain morphological and functional

organization. Such connectivity is conveyed by specific pathways or tracts in the

white matter. Diffusion-weighted magnetic resonance imaging detects the

diffusivity of water molecules in three dimensions. Diffusivity is anisotropic in

oriented tissues such as fiber tracts. In the present study, we used this method to

map (in terms of orientation, location, and size) the "stem" (compact portion) of

the principal association, projection, and commissural white matter pathways of

the human brain in vivo, in 3 normal subjects. In addition, its use in clinical

neurology is illustrated in a patient with left inferior parietal lobule embolic

infarction in whom a significant reduction in relative size of the stem of the left

superior longitudinal fasciculus was observed. This represents an important

method for the characterization of major association pathways in the living human

that are not discernible by conventional magnetic resonance imaging. In the clinical

domain, this method will have a potential impact on the understanding of the

diseases that involve white matter such as stroke, multiple sclerosis, amyotrophic

lateral sclerosis, head injury, and spinal cord injury.

207. Maldjian, J. A.; Schulder, M.; Liu, W. C.; Mun, I. K.; Hirschorn, D.; Murthy, R.;

Carmel, P.; Kalnin, A. Intraoperative functional MRI using a real-time

neurosurgical navigation system. J-Comput-Assist-Tomogr. 1997 Nov; 21(6):

910-2; ISSN: 0363-8715.

UNITED-STATES. A 42-year-old-man had focal left hand motor seizures. MR

studies demonstrated a right posterior frontal brain tumor. Functional MRI was

performed, localizing the motor cortex posterior to the lesion. The functional

images were integrated with a neurosurgical navigation computer. A real-time

intraoperative display of the anatomic and functional images was produced,

registered to a neurosurgical probe. Excellent correlation was demonstrated

between the functional maps and invasive electrophysiologic mapping performed

at the time of craniotomy.

208. Maquet, P.; Lejeune, H.; Pouthas, V.; Bonnet, M.; Casini, L.; Macar, F.; Timsit

Berthier, M.; Vidal, F.; Ferrara, A.; Degueldre, C.; Quaglia, L.; Delfiore, G.; Luxen,

A.; Woods, R.; Mazziotta, J. C.; Comar, D. Brain activation induced by

estimation of duration: a PET study. Neuroimage. 1996 Apr; 3(2): 119-26; ISSN:

1053-8119.

UNITED-STATES. Duration information about a visual stimulus requires

processing as do other visual features such as size or intensity. Using positron

emission tomography, iterative H215O infusions, and statistical parametric

mapping, we investigated the neural correlates of time processing. Nine normal

subjects underwent six serial rCBF. Three tasks were studied: (a) A temporal

generalization task (D task) in which the subjects had to judge (by pressing one of

two keys) whether the duration of the illumination of a green LED was equal to or

different from that of a previously presented standard; (b) An intensity

generalization task (I task) in which the judgment concerned the intensity of the

LED; and (c) A control task (C task) in which the subjects had to press one of the

two keys at random in response to LED illumination. A significant increase in

rCBF during the D task, compared to that during the C task, was observed in right

prefontal cortex, right inferior parietal lobule, anterior cingulate cortex, vermis, and

a region corresponding to the left fusiform gyrus. A significant increase in rCBF

during the I task, compared to that during the C task, was observed in right

prefontal cortex, right inferior parietal lobule, right extrastriate cortex, anterior

cingulate cortex, left inferior parietal lobule, vermis, and two symmetrical regions

corresponding to the fusiform gyri. No significant activation was observed in the

D task when compared to that in the I task. We propose that these cortical maps

are best explained by the recruitment of visual attention and memory structures,

which play a major role in prospective time judgements as indicated by behavioral

studies. The data also suggest that the temporal dimension of a visual stimulus is

processed in the same areas as other visual attributes.

209. Mark, V. W.; Heilman, K. M. Diagonal neglect on cancellation. Neuropsychologia.

1997 Nov; 35(11): 1425-36; ISSN: 0028-3932.

ENGLAND. Patients with right hemisphere injury frequently neglect to cancel

targets primarily in the left part of the page nearest the body. Since this region is

diagonally opposite the area from where such patients usually begin cancelling,

near left ('diagonal') neglect may be consequent to stimulus order effects ('fatigue').

We evaluated the persistence of near left neglect in nine stroke patients when they

had to cancel either the near or the far half of the page before proceeding to the

other half. Our results showed that near left neglect on the page was largely

unaffected by cancellation order. Furthermore, a near left gradient of omissions

was established within both radial (near and far) halves of the page, as well as for

the entire page. Our findings suggest that diagonal cancellation neglect is unrelated

to fatigue and reflects a consistent, two-dimensional disorder of spatial attention.

Such neglect may be related to the extent of the visible stimulus array, as well as

to the array's location in egocentric space.

210. Marshall, J. C.; Halligan, P. W.; Fink, G. R.; Wade, D. T.; Frackowiak, R. S. The

functional anatomy of a hysterical paralysis. Cognition. 1997 Jul; 64(1): B1-8;

ISSN: 0010-0277.

NETHERLANDS. The concept of a conversion disorder (such as hysterical

paralysis) has always been controversial (Ron, M.A. (1996). Somatization and

conversion disorders. In: B.S. Fogel, R.B. Schiffer & S.M. Rao (Eds.),

Neuropsychiatry. Williams and Wilkins, Baltimore, MD). Although the diagnosis

is recognised by current psychiatric taxonomies, many physicians still regard such

disorders either as feigned or as failure to find the responsible organic cause for the

patient's symptoms. We report a woman with left sided paralysis (and without

somatosensory loss) in whom no organic disease or structural lesion could be

found. By contrast, psychological trauma was associated with the onset and

recurrent exacerbation of her hemiparalysis. We recorded brain activity when the

patient prepared to move and tried to move her paralysed (left) leg and when she

prepared to move and did move her good (right) leg. Preparing to move or moving

her good leg, and also preparing to move her paralysed leg, activated motor and/or

premotor areas previously described with movement preparation and execution.

The attempt to move the paralysed leg failed to activate right primary motor

cortex. Instead, the right orbito-frontal and right anterior cingulate cortex were

significantly activated. We suggest that these two areas inhibit prefrontal (willed)

effects on the right primary motor cortex when the patient tries to move her left

leg.

211. Martin, A.; Wiggs, C. L.; Weisberg, J. Modulation of human medial temporal lobe

activity by form, meaning, and experience. Hippocampus. 1997; 7(6): 587-93;

ISSN: 1050-9631.

UNITED-STATES. Clinically, the hallmark of the human amnesic syndrome is

an impaired ability to consciously recollect or remember daily events. If the

medial region of the temporal lobes, including the hippocampus and related

structures, is critical for establishing these new memories, then this brain region

should be active whenever events are experienced, regardless of whether subjects

are asked explicitly to learn and remember. Here we show that the medial

temporal region is active during encoding and that the hemisphere activated and

the amount of activation depend on the type of stimulus presented (objects or

words), whether the stimulus can be encoded for meaning (real objects and words

versus nonsense objects and words), and task experience (first versus the second

time a task is performed). These findings demonstrate that the medial temporal

lobe memory system is engaged automatically when we attend to a perceptual

event and that the location and amount of activation depend on stimulus

characteristics (physical form, meaning) and experience.

212. Martin, A.; Wiggs, C. L.; Weisberg, J. Modulation of human medial temporal lobe

activity by form, meaning, and experience. Hippocampus. 1997; 7(6): 587-93;

ISSN: 1050-9631.

UNITED-STATES. Clinically, the hallmark of the human amnesic syndrome is

an impaired ability to consciously recollect or remember daily events. If the

medial region of the temporal lobes, including the hippocampus and related

structures, is critical for establishing these new memories, then this brain region

should be active whenever events are experienced, regardless of whether subjects

are asked explicitly to learn and remember. Here we show that the medial

temporal region is active during encoding and that the hemisphere activated and

the amount of activation depend on the type of stimulus presented (objects or

words), whether the stimulus can be encoded for meaning (real objects and words

versus nonsense objects and words), and task experience (first versus the second

time a task is performed). These findings demonstrate that the medial temporal

lobe memory system is engaged automatically when we attend to a perceptual

event and that the location and amount of activation depend on stimulus

characteristics (physical form, meaning) and experience.

213. Martin Loeches, M.; Rubia, F. J. Encoding into working memory of spatial location,

color, and shape: electrophysiological investigations. Int-J-Neurosci. 1997 Oct;

91(3-4): 277-94; ISSN: 0020-7454.

ENGLAND. Event-related potentials (ERP) were recorded while subjects

memorized either the location, the color or the shape of stimuli which could be

located in 1 of 4 positions relative to a central fixation point (top, bottom, left or

right), be of 1 of 4 positions relative to a central fixation point (top, bottom, left

or right), be of 1 of 4 colors (white, green, red or blue), and present 1 of 4 shapes

(triangle, cross, circle or square). These ERP were compared to ERP recorded

while subjects looked at the same stimuli but performed other control,

nonmemory tasks. Only ERP corresponding to the memorization of spatial

location showed a differential pattern which could be specifically attributed to

memory encoding processes. This reveals an important difference in ERP

modulation between a working memory subsystem for spatial location and other

subsystem (or subsystems) for color or shape, which would provide evidence

supporting the existence of different working memory subsystems for visual

information in the brain.

214. Martin, R. F.; Bowden, D. M. A stereotaxic template atlas of the macaque brain for

digital imaging and quantitative neuroanatomy. Neuroimage. 1996 Oct; 4(2): 119-

50; ISSN: 1053-8119.

UNITED-STATES. A stereotaxic brain atlas of the longtailed macaque (Macaca

fascicularis) is presented in a format suitable for use as a template atlas of the

macaque brain. It includes most of the brain segmented to show the boundaries of

landmark structures such that every point in the brain can be represented by a

unique set of coordinates in three-dimensional space and ascribed unambiguously

to one and only one primary structure. More than 400 structures are represented,

including 360 volumetric structures, which constitute the substance of the brain,

and 50 superficial features. To facilitate use with ventriculography, magnetic

resonance imaging, and other noninvasive imaging techniques, the stereotaxic space

is referenced to internal landmarks, viz., the anterior commissure and posterior

commissure; the center of the anterior commissure at the midline is the origin of

the stereotaxic axes. Reference of stereotaxis to this bicommissural space

facilitates structural comparison with human brain atlases, which are commonly

referenced to the biocommissural line. It also facilitates comparison of brains of

different nonhuman primate species by providing a template brain against which

to compare size and internal variability. Thirty-three coronal sections at 1-mm

intervals from the spinomedullary junction to the rostral extreme of the caudate

nucleus show most structures of the hindbrain, midbrain, and subcortical

forebrain. Separately, four side views and 16 coronal sections show cortical

structures. Structures are represented by outlines of their boundaries and labeled

according to NeuroNames, a systematic English nomenclature of human and

nonhuman primate neuroanatomy. Abbreviations are based on a protocol designed

to facilitate cross-species comparisons. Instructions are provided for: (1) locating

sites from the Template Atlas in the conventional stereotaxic space of an

experimental animal, (2) locating sites identified by conventional stereotaxis in the

Template Atlas, and (3) using the Template Atlas to collate, compare, and display

image information (e.g., labeled cells, recording sites, stimulation sites, lesions)

from multiple animals.

215. Mason, G. F.; Harshbarger, T.; Hetherington, H. P.; Zhang, Y.; Pohost, G. M.;

Twieg, D. B. A method to measure arbitrary k-space trajectories for rapid MR

imaging. Magn-Reson-Med. 1997 Sep; 38(3): 492-6; ISSN: 0740-3194.

UNITED-STATES. A method to measure arbitrary k-space trajectories was

developed to compensate for nonideal gradient performance during rapid magnetic

resonance (MR) imaging with actively or nonactively shielded gradients at a

magnetic field strength of 4.1 T. Accurate MR image reconstruction requires

knowledge of the k-trajectory produced by the gradient waveforms during k-space

sampling. Even with shielded gradients, residual eddy currents and imperfections

in gradient amplifier performance can cause the true k-space trajectory to deviate

from the ideal trajectory. The k-space determination was used for spiral gradient-

echo imaging fo the human brain. While individual calibrations are needed for new

pulse sequences, the method of k-space determination can be used for any

sequence of preparation pulses and readout gradient waveforms and should prove

useful for other trajectories, including the rastered lines of echo-planar imaging.

216. Matsumoto, T.; Yokoi, K.; Mukaida, N.; Harada, A.; Yamashita, J.; Watanabe, Y.;

Matsushima, K. Pivotal role of interleukin-8 in the acute respiratory distress

syndrome and cerebral reperfusion injury. J-Leukoc-Biol. 1997 Nov; 62(5): 581-7;

ISSN: 0741-5400.

UNITED-STATES. Neutrophil recruitment is one of the hallmarks of acute

inflammation. A potent neutrophil chemotactic and activating factor, interleukin-8

(IL-8), has been demonstrated to be elevated in body fluids in various human

diseases and experimental animal models. Recent investigations on animal disease

models using blocking antibodies to IL-8 have revealed the essential involvement

of IL-8 in acute inflammation. We previously reported that the administration of a

neutralizing antibody against IL-8 prevented the neutrophil infiltration and

neutrophil-mediated tissue injury in several animal studies. In addition, we have

recently demonstrated that anti-IL-8 treatment is also effective in prevention of

two models that are very relevant to clinical situations: cerebral reperfusion injury

and endotoxemia-induced acute respiratory distress syndrome-like lung injury.

These results further support the hypothesis that IL-8 has a pivotal role and is a

novel target for therapeutic intervention in neutrophil-mediated injury.. 0.

217. Matthew, E.; Hill, T. C. Brain mapping with single photon emission CT. Radiology.

1998 Feb; 206(2): 483-9; ISSN: 0033-8419.

UNITED-STATES. PURPOSE: To investigate the feasibility of performing brain

mapping studies by using cortical activation paradigms and single photon

emission computed tomography (SPECT) and to evaluate methods of analysis.

MATERIALS AND METHODS: Twenty healthy volunteers underwent

technetium-99m bicisate SPECT under baseline conditions and during either full-

field or right hemifield visual stimulation with a black and white reversing

checkerboard pattern. Changes in regional cerebral perfusion were measured by

using regions of interest (ROIs) and statistical parametric mapping. RESULTS:

ROI analysis identified statistically significant increases in perfusion in the

occipital cortex with full-field visual stimulation (mean +/- standard error of the

mean percentage change from baseline: left, 8.0 +/- 1.5; right, 6.6 +/- 2.4). With

right hemifield visual stimulation, perfusion was significantly increased only in the

left occipital cortex (left, 5.2 +/- 1.5; right, -0.2 +/- 1.9). Statistical parametric

mapping showed areas of activation (more than 100 voxel clusters showed

significant change from baseline at a threshold value of P < or = .005 or z > or =

2.58) in the left primary visual cortex (right hemifield visual stimulation) and in

both right and left primary visual areas (full-field visual stimulation).

CONCLUSION: Brain mapping studies were preformed with Tc-99m bicisate

SPECT, and activation-induced changes were visualized and measured. These

methods can be applied to develop improved methods of diagnosis and

assessment of treatment outcome in patients with neuropsychiatric disorders.. 0;

0; 0; 4371-52-2.

218. May, J.; White, G. H.; Waugh, R.; Brennan, J. Endoluminal repair of internal carotid

artery aneurysm: a feasible but hazardous procedure. J-Vasc-Surg. 1997 Dec;

26(6): 1055-60; ISSN: 0741-5214.

UNITED-STATES. PURPOSE: The aim of this study was to report the repair

of an aneurysm of the internal carotid artery using the endoluminal method.

METHODS: A 70-year-old male patient noted a swelling in the right side of his

neck 22 years after endarterectomy of the right internal carotid artery. Duplex

ultrasound confirmed the clinical diagnosis of aneurysm of the internal carotid

artery. Further investigation included contrast-enhanced computed tomographic

(CT) scanning and carotid angiography performed via a retrograde femoral

approach. The aneurysm contained thrombus and was 3 cm in diameter and in

length. It extended superiorly from a point 0.5 cm above the carotid bifurcation to

a point estimated to be 2 cm from the base of the skull. Repair of the aneurysm

was undertaken using the endoluminal method. A self-expanding endograft 8 mm

in diameter and 4 cm in length was introduced through a 12F sheath in the

common carotid artery. An on-table completion angiogram of the right-sided

extracranial carotid arteries and the intracranial internal carotid artery and branches

was obtained. RESULTS: The completion angiogram and postoperative CT scan

confirmed exclusion of the aneurysm sac from the circulation. The patient awoke

from anesthesia with complete paralysis of the left arm. Recovery of movement

commenced 1 hour later. A brain CT scan demonstrated the event to be an embolic

stroke. Strength had returned by 7 days. Function of the arm was good 1 month

after operation, but coordination for fine movements was lacking. At the 6-month

follow-up, good arm function was maintained. A duplex ultrasound scan

demonstrated not only continued exclusion of the aneurysm sac but occlusion of

the endograft, also. CONCLUSIONS: Endoluminal repair of aneurysms of the

internal carotid artery is feasible but carries the risk of major morbidity as a result

of peripheral embolization and early occlusion of the endograft.

219. McCarley, R. W.; Shenton, M. E.; O'Donnell, B. F.; Nestor, P. G. Uniting Kraepelin

and Bleuler: the psychology of schizophrenia and the biology of temporal lobe

abnormalities. Harv-Rev-Psychiatry. 1993 May; 1(1): 36-56; ISSN: 1067-3229.

UNITED-STATES. Bleuler and Kraepelin are described as icons of the

aggressively psychological and aggressively biologic approaches to schizophrenia.

We suggest that methodologic advances in studying the function and structure of

the brain now allow a reconciliation of these seemingly dissimilar approaches,

particularly in the temporal lobe. We begin with a brief historic overview of these

different approaches to schizophrenia and then describe structural (magnetic

resonance imaging [MRI]), functional (event-related potential [ERP]), and

neuropsychological studies in this disorder, including a summary of work

conducted in our own laboratory. Recent MRI investigations agree on the

presence of volume reductions in schizophrenia in the medial temporal lobe

structures of the hippocampus-amygdala complex and of the para-hippocampal

gyrus. Furthermore, two recent studies also indicate volume reductions in the

superior temporal gyrus (STG). These volume reductions are most prominent in

male patients and in the left hemisphere of right-handed patients with

schizophrenia. Along with structural studies, there has been a burgeoning interest

in MRI-clinical correlations, with volume reductions in the anterior STG being

associated with hallucinations and those in the posterior STG being associated

with thought disorder. Functional ERP studies also implicate the importance of

the temporal lobe in schizophrenia; in addition, ERP abnormalities have been

directly associated with a left greater than right MRI volume reduction of the

posterior STG. Neuropsychological studies in nonpsychiatric patients are also

consistent with a pattern of functional deficits shown to arise from temporal lobe

abnormalities, whereas direct MRI-neuropsychological correlations in

schizophrenic patients show that decreased performance on tests of verbal

memory, abstraction, and categorization correlates with reduced MRI volume of

left and right temporal lobe structures. Integration of these findings with those

from basic neuroscience suggests a possible role of excitatory amino acid

neurotransmission dysregulation and excitotoxicity in the pathology of

schizophrenia. A data-based pathophysiologic characterization of schizophrenia

is now becoming a reality, and the next few years should see a further unification

of the Kraepelinian and Bleulerian approaches to this disorder.

220. McClellan, A. D.; Hagevik, A. Descending control of turning locomotor activity in

larval lamprey: neurophysiology and computer modeling. J-Neurophysiol. 1997

Jul; 78(1): 214-28; ISSN: 0022-3077.

UNITED-STATES. The purpose of the present study was to examine the

mechanisms that produce natural spontaneous turning maneuvers in larval

lamprey. During swimming, spontaneous turning movements began with a larger-

than-normal bending of the head to one side. Subsequently, undulations

propagated down the body with greater amplitude on the side ipsilateral to the

turn. During turning to one side, which usually occurred within one cycle, the

amplitude and duration of ipsilateral muscle burst activity as well as overall cycle

time increased significantly with increasing turn angle. In in vitro brain/spinal cord

preparations, brief electrical stimulation applied to the left side of the oral hood at

the onset of locomotor burst activity on the right side of the spinal cord produced

turninglike motor activity. During the perturbed cycle, the duration and amplitude

of the burst on the right as well as cycle time were significantly larger than during

preceding control cycles. In several lower vertebrates, unilateral stimulation in

brain stem locomotor regions elicits asymmetric, turninglike locomotor activity. In

the lamprey, unilateral chemical microstimulation in brain stem locomotor regions

elicited continuous asymmetric locomotor activity, but there was little change in

cycle time, as occurs during the single turning cycles in whole animals. The

descending mechanisms responsible for producing turning locomotor activity were

examined with the use of a computer model consisting of left and right phase

oscillators in the spinal cord that were coupled by net reciprocal inhibition. With

relatively weak reciprocal coupling, a brief unilateral descending excitatory input

to one oscillator produced effects ipsilaterally, but there was little effect on the

contralateral oscillator. Turninglike patterns could be produced by each of the

following modifications of the model: 1) unilateral descending input and relatively

strong reciprocal coupling; 2) unilateral descending input that phase shifted as

well as increased the amplitude of the waveform generated by an oscillator on one

side; and 3) brief descending modulatory inputs that excited the oscillator on one

side and inhibited the contralateral oscillator. In all three cases, there was an

increase in "burst" duration ipsilateral to the excitatory input and an increase in

cycle time, similar to turning locomotor activity in whole animals. It is likely that

turning maneuvers are mediated by descending modulatory inputs primarily to the

spinal oscillator networks, which control the timing of burst activity, but perhaps

also to motoneurons for axial musculature.

221. McGlinchey Berroth, R.; Bullis, D. P.; Milberg, W. P.; Verfaellie, M.; Alexander, M.;

D'Esposito, M. Assessment of neglect reveals dissociable behavioral but not

neuroanatomical subtypes. J-Int-Neuropsychol-Soc. 1996 Sep; 2(5): 441-51;

ISSN: 1355-6177.

ENGLAND. In the current study, we investigated whether standard assessment

techniques of visuospatial neglect are sensitive to detecting dissociable subtypes.

We administered a battery of tasks commonly used to detect the presence of

visuospatial neglect to 120 patients with unilateral right hemisphere infarcts and,

in most cases, performed a systematic analysis of their lesions to quantify and

localize brain damage. Using a factor analysis, we discovered seven relatively

independent constructs, three of which were specifically related to the presence of

left hemispatial neglect: Left Attentional Processing, Line Bisection, and Word

Reading. Impairments in two of these factors, Left Attentional Processing and

Line Bisection, occurred together in most cases but also occurred independently in

38 cases. There were no cases in whom Word Reading was present without

concomitant deficits in one or the other two factors. These three factors could not

be distinguished neuroanatomically; that is, lesions were equally likely in the

temporal/parietal cortex, dorsolateral frontal cortex, or in deep frontal structures.

These data confirm the notion that hemispatial neglect is a complex and

multifaceted disorder composed of cognitively independent processes. These

processes, however, cannot be dissociated neuroanatomically based on currently

available assessment techniques.

222. McIntyre, D. J.; Hennel, F.; Morris, P. G. SPARE: A robust method for magnetic

resonance imaging in inhomogeneous fields. J-Magn-Reson. 1998 Jan; 130(1): 58-

62; ISSN: 1090-7807.

UNITED-STATES. An imaging sequence based on a spin-echo train has been

developed which is free from geometric distortions in the imaging plane due to

main field inhomogeneity. Such inhomogeneities, and chemical shifts, cause only a

displacement in the selected slice, which is minimized by the use of high gradient

strengths and short radiofrequency pulses. Additionally, variations in the

radiofrequency field strength cause variations in the image amplitude but cause no

other artifacts. This allows the use of low-flip-angle refocusing pulses, reducing

the power deposition to levels which are safe in vivo at high field strengths. The

sequence was implemented on a Bruker whole-body 3T system. Example images

from a perfluorocarbon phantom and a human head are presented.. 0.

223. McKeefry, D. J.; Watson, J. D.; Frackowiak, R. S.; Fong, K.; Zeki, S. The activity in

human areas V1/V2, V3, and V5 during the perception of coherent and incoherent

motion. Neuroimage. 1997 Jan; 5(1): 1-12; ISSN: 1053-8119.

UNITED-STATES. We have used the technique of positron emission

tomography to study and compare the cortical activity produced when humans

view a pattern of small squares moving incoherently with respect to one another

and when the same pattern moves coherently and unidirectionally. A stationary

version of the stimulus acted as a control. Our choice of paradigm was inspired by

psychophysical models and physiological studies in the macaque monkey which

show that directionally selective cells in V5 respond optimally to unidirectional

coherent motion, whereas those of V1 respond to motion within their receptive

fields, regardless of the motion in surrounding parts. Our results show that human

V1/V2, V3, and V5 are all activated by both types of motion stimuli. Incoherent

motion, however, proved to be more effective than coherent motion in activating

V1/V2 and V5. Thus the higher perceptual salience of unidirectional coherent

motion in comparison to incoherent motion is not reflected by any increased

activation of human area V5.

224. McKeefry, D. J.; Zeki, S. The position and topography of the human colour centre as

revealed by functional magnetic resonance imaging. Brain. 1997 Dec; 120( Pt 12):

2229-42; ISSN: 0006-8950.

ENGLAND. We used a colour Mondrian--an abstract scene with no recognizable

objects--and its achromatic version to image the change in blood oxygenation in

the brains of 12 human subjects, with the aim of learning more about the position

and variability of the colour centre in the human brain. The results showed a

consistent association of colour stimulation with activation of an area that is

distinct from the primary visual areas, and lies in the ventral occipitotemporal

cortex; we refer to it as human V4. The position of human V4, as defined on

functional grounds, varies between individuals in absolute terms but is invariably

found on the lateral aspect of the collateral sulcus on the fusiform gyrus. There

was no indication of lingual gyral activation. In further studies designed to reveal

the topographic map within V4, we stimulated the superior and inferior visual

fields separately, using the same stimuli. We found that human V4 contains a

representation of both the superior and inferior visual fields. In addition, there

appears to be retinotopic organization of V4 with the superior visual field being

represented more medially on the fusiform gyrus and the inferior field more

laterally, the two areas abutting on one another. We find no evidence that suggests

the existence of a separate representation of the inferior hemifield for colour in

more dorsolateral regions of the occipital lobe.. 7782-44-7.

225. McKeefry, D. J.; Zeki, S. The position and topography of the human colour centre as

revealed by functional magnetic resonance imaging. Brain. 1997 Dec; 120( Pt 12):

2229-42; ISSN: 0006-8950.

ENGLAND. We used a colour Mondrian--an abstract scene with no recognizable

objects--and its achromatic version to image the change in blood oxygenation in

the brains of 12 human subjects, with the aim of learning more about the position

and variability of the colour centre in the human brain. The results showed a

consistent association of colour stimulation with activation of an area that is

distinct from the primary visual areas, and lies in the ventral occipitotemporal

cortex; we refer to it as human V4. The position of human V4, as defined on

functional grounds, varies between individuals in absolute terms but is invariably

found on the lateral aspect of the collateral sulcus on the fusiform gyrus. There

was no indication of lingual gyral activation. In further studies designed to reveal

the topographic map within V4, we stimulated the superior and inferior visual

fields separately, using the same stimuli. We found that human V4 contains a

representation of both the superior and inferior visual fields. In addition, there

appears to be retinotopic organization of V4 with the superior visual field being

represented more medially on the fusiform gyrus and the inferior field more

laterally, the two areas abutting on one another. We find no evidence that suggests

the existence of a separate representation of the inferior hemifield for colour in

more dorsolateral regions of the occipital lobe.. 7782-44-7.

226. Mega, M. S.; Thompson, P. M.; Cummings, J. L.; Back, C. L.; Xu, M. L.; Zohoori,

S.; Goldkorn, A.; Moussai, J.; Fairbanks, L.; Small, G. W.; Toga, A. W. Sulcal

variability in the Alzheimer's brain: correlations with cognition. Neurology. 1998

Jan; 50(1): 145-51; ISSN: 0028-3878.

UNITED-STATES. We mapped the three dimensional (3D) extents and

variability of selected sulci in the Alzheimer's brain and explored the relationship

between sulcal pattern and patient's cognitive performance. High-resolution MRIs

of 10 patients with probable Alzheimer's disease (AD) were linearly transformed

into a standard "normalized" 3D atlas (known as the Talairach coordinate system)

and, on each relevant slice, contours of the left and right Sylvian fissure, anterior

and posterior calcarine, callosal, parietooccipital, and cingulate sulci and the floor

of the temporal horn of the lateral ventricle were traced. These landmarks were

chosen because of their relative invariant location across individuals and because

they demarcate functional boundaries relevant in AD. The sulcal contours were

resolved into two-dimensional surfaces that cut through a brain volume. All 10

patients' sulcal surfaces were averaged to determine their mean spatial locations in

the Talairach coordinate system. The 3D spatial extents of each patient's sulci

were compared with their disease severity based on neuropsychological

performance. The 3D sulcal variability, within the "normalized" atlas space,

ranged from 4.0 mm for the left callosal sulcus to 9.1 mm for the left Sylvian

fissure. Significant correlations were found among the spatial extents for the

posterior floor of the right temporal horn of the lateral ventricle (r = -0.89, p <

0.001 for vertical extent) and right anterior calcarine sulcus (r = -0.75, p < 0.01 for

anterior-posterior extent) with copying ability of the Rey-Osterrieth Complex

Figure; the right anterior calcarine also had a significant relationship (r = -0.72, p =

0.02 for anterior-posterior extent) with performance on the Block Design subtest

from the Wechsler Adult Intelligence Scale-Revised. Verbal fluency performance

measured by the Controlled Oral Word Association Test was significantly related

to the left cingulate (r = 0.91, p < 0.001 for anterior-posterior extent, and r = -

0.82, p < 0.01 for vertical extent) and right cingulate (r = -0.72, p < or = 0.02 for

vertical extent) sulci. This exploratory study is the first to evaluate the

relationship between 3D sulcal variability and cognition; our preliminary findings

suggest that the 3D pattern of sulci in the AD brain is related to the severity of

the disease as reflected by cognitive performance. In the Talairach brain atlas,

sulcal variability, within an AD population, approaches 1 cm. This large

variability requires correction when functional imaging data are transformed into

the Talairach atlas space to "normalize" individual morphologic differences.

227. Mehta, Z.; Newcombe, F. Dissociable contributions of the two cerebral hemispheres

to judgments of line orientation. J-Int-Neuropsychol-Soc. 1996 Jul; 2(4): 335-9;

ISSN: 1355-6177.

ENGLAND. A previous study of the performance of men with chronic unilateral

focal brain lesions (due to wartime missile injury) on a standard test of line

orientation suggested a left hemisphere (LH) as well as a right hemisphere (RH)

contribution to visuospatial processing. The present study was designed to

fractionate the variables that could underlie this unexpected finding and thereby to

tease out the mechanisms involved in LH as compared with RH processing. A

simpler ("purer") version of the standard line orientation task was used, as were

two other versions in which matching in an array and matching with distractors

were measured. The findings confirmed the hypothesis of RH involvement in the

purer task of metric measurement and suggested that the LH has an important role

in keeping track decisions and updating decisions in more complex aspects of line

orientation judgment.

228. Mentis, M. J.; Alexander, G. E.; Grady, C. L.; Horwitz, B.; Krasuski, J.; Pietrini, P.;

Strassburger, T.; Hampel, H.; Schapiro, M. B.; Rapoport, S. I. Frequency

variation of a pattern-flash visual stimulus during PET differentially activates

brain from striate through frontal cortex. Neuroimage. 1997 Feb; 5(2): 116-28;

ISSN: 1053-8119.

UNITED-STATES. We evaluate regional cerebral blood flow (rCBF) in 19

healthy elderly subjects, mean age 64 +/- 11 (SD, years), during a passive visual

stimulus in which pattern-flash frequency was parametrically manipulated. Using

goggles with a grid of red lights imbedded into each lens, we performed five

positron emission tomography (PET) H2(15)O water scans on each subject at

alternating (left to right eye) flash frequencies of 0, 1, 4, 7, and 14 Hz. We found a

biphasic rising and falling rCBF response in the striate cortex (7 Hz peak) and left

anterior cingulate (4 Hz peak), 1 Hz activation in left middle temporal gyrus (V5),

monotonically increasing rCBF in posterior areas (lateral and inferior visual

association areas, Brodmann 18 and 19), and monotonically decreasing rCBF in

anterior areas (frontal, cingulate, and superior temporal) predominantly in right

hemisphere. We suggest the striate rCBF changes at all frequencies primarily

reflect lateral geniculate input, the middle temporal activation at 1 Hz reflects

perception of apparent motion, and the posterior extrastriate rCBF monotonic

increase represents a neural response to increasing luminance intensity and form

and color complexity that occur as pattern-flash frequency increases. The anterior

monotonic rCBF decrease may represent active cross-modal functional

suppression of brain areas irrelevant for processing the passive visual stimulus.

Pattern-flash rCBF responses were highly reproducible (no series effect), more so

in posterior than in anterior brain regions. The reproducibility and systematically

changing rCBF responses to this passive stimulus suggest that it could be

successfully used as a disease probe to evaluate neural function and drug effects in

cognitively impaired patients.

229. Merians, A. S.; Clark, M.; Poizner, H.; Macauley, B.; Gonzalez Rothi, L. J.; Heilman,

K. M. Visual-imitative dissociation apraxia. Neuropsychologia. 1997 Nov; 35(11):

1483-90; ISSN: 0028-3932.

ENGLAND. Liepmann posited that, in right handers, the left parietal lobe

contains movement formulas or representations. Therefore, performance failures

may be induced by degraded representations, a failure of these representations to

influence motor systems or a failure of stimuli to fully access these

representations. Imitation may help the performance of subjects with degraded

representations. However, patients who have impaired visual access to movement

representations may perform more poorly with imitation than to verbal command.

Trajectories of repetitive 'slicing' gestures made by a previously reported subject

(Raymer et al.) with an infarction in the left visual association cortex (left occipital

and inferior temporal lobe) that spared the parietal lobe were contrasted with

those of three apraxic subjects with lesions that included the left parietal lobe and

four non-brain-damaged control subjects. All subjects were asked to produce the

gesture to verbal command and to imitation. Movements of the left hand, wrist,

elbow and shoulder were digitized from neighboring views, reconstructed in three

dimensions, and analysed graphically and numerically. The apraxic subjects with

left parietal damage were unable to maintain the proper linearity and

spatiotemporal attributes of their wrist motions and showed interjoint

coordination deficits. Their deficits were most pronounced to verbal command,

with their movements improving though remaining poorly performed when they

imitated. The subject with the left occipital and inferior temporal lesion that

spared parietal cortex, however, showed an opposite pattern. This subject

exhibited close to normal performance when producing the movement to verbal

command, but significant deficits when imitating.

230. Mikkonen, M.; Soininen, H.; Pitkanen, A. Distribution of parvalbumin-, calretinin-,

and calbindin-D28k-immunoreactive neurons and fibers in the human entorhinal

cortex. J-Comp-Neurol. 1997 Nov 10; 388(1): 64-88; ISSN: 0021-9967.

UNITED-STATES. Parvalbumin, calretinin, and calbindin-D28k are calcium-

binding proteins that are located in largely nonoverlapping neuronal populations

in the brain. The authors studied the distribution of parvalbumin-, calretinin-, and

calbindin-D28k-immunoreactive (ir) cells, fibers, terminals, and neuropil in the

eight subfields of the human entorhinal cortex. The distribution of each of the

three calcium-binding proteins largely followed the cytoarchitectonic borders of

the eight entorhinal subfields, although the regional and laminar distributions of

the three proteins were segregated rather than overlapping. The highest density of

parvalbumin-ir neurons and terminals was found in the caudal and lateral subfields

of the entorhinal cortex. Calretinin and calbindin-D28k immunoreactivities were

high rostromedially, although a large number of calretinin and calbindin-D28k

neurons were also found in the caudal subfields. All parvalbumin-ir cells had a

morphological appearance of nonpyramidal neurons. Parvalbumin-ir terminals

formed basket-like formations around unstained somata and cartridges, suggesting

that parvalbumin neurons compose a subpopulation of gamma-aminobutyric acid

(GABA)ergic basket cells and chandelier cells, respectively. Although calretinin

and calbindin-D28k were also found in numerous nonpyramidal neurons, both

were also located in pyramidal-shaped neurons in layers V and VI (calretinin) and

in layers II and III (calbindin) of the entorhinal cortex, suggesting that they play

roles in projection neurons as well. Moreover, the high density of nonpyramidal

neurons containing calcium-binding proteins in layers II and III of the entorhinal

cortex suggests that they form an integral component of a network that controls

the entorhinal outputs to the hippocampus. Furthermore, the largely

nonoverlapping distributions of the parvalbumin-, calretinin-, and calbindin-ir

neuronal populations in the entorhinal cortex indicate that each of them may

modulate a different subset of topographically organized entorhinal outputs.. 0;

0; 0; 0.

231. Milner, B.; Johnsrude, I.; Crane, J. Right medial temporal-lobe contribution to object-

location memory. Philos-Trans-R-Soc-Lond-B-Biol-Sci. 1997 Oct 29; 352(1360):

1469-74; ISSN: 0962-8436.

ENGLAND. An important aspect of normal human memory, and one humans

share with many other species, is the ability to remember the location of objects

in their environment. There is by now strong evidence from the study of epileptic

patients undergoing brain surgery that right temporal-lobe lesions that encroach

extensively upon the hippocampal and parahippocampal gyrus impair the

delayed, but not the immediate, recall of the location of objects within a random

array. These findings have now been extended to a multiple-trial, spatial-array

learning task; by including not only patients tested after unilateral anterior

temporal lobectomy but also those with a selective left or right

amygdalohippocampectomy, it has been shown that the deficits associated with

right hippocampal lesions are not dependent upon conjoint damage to the lateral

temporal neocortex. Furthermore, the fact that on the learning task no group

differences were seen on Trial 1, at zero delay, strengthened the view that the

impairment was in the maintenance and subsequent retrieval of information rather

than in its initial encoding. These results left unresolved the question of whether

the deficit was in the mediation of object-place associations or whether it could be

reduced to a more general impairment in memory for location as such. Also left

unanswered was the neuroanatomical question as to the relative contributions of

the hippocampus and the parahippocampal gyrus to the performance of the

experimental tasks. These questions were addressed in two blood-flow activation

studies that made use of positron emission tomography (PET) and magnetic

resonance imaging (MRI) and incorporated computerized versions of object-

location and simple-location memory tasks. Taken together, the results point to a

special contribution from the anterior part of the right parahippocampal gyrus,

probably corresponding to the entorhinal cortex, to the retrieval of object-place

associations, a result consonant with neurophysiological findings in non-human

primates.

232. Mize, R. R.; Thouron, C.; Lucas, L.; Harlan, R. Semiautomatic image analysis for

grain counting in in situ hybridization experiments. Neuroimage. 1994 Jun; 1(3):

163-72; ISSN: 1053-8119.

UNITED-STATES. We have developed a computer image analysis procedure for

counting autoradiographic grains in in situ hybridization experiments. The

procedure automatically estimates the number of autoradiographic grains over

cells and measures cell number and size so that grain density per unit cell area can

be calculated. Advantages include the clear separation of grains and cells, using

chromatic and spatial filters to enhance the image; the use of gray level operators

to extract cells from grains; and the use of binary operators for separating apposed

or partially overlapping cells and grains. Comparison of manual and automated

grain counts revealed a significant correlation between human and computer

estimations of grain number. However, the automatic grain counting technique

consistently underestimated the number of grains when grain density was high.

Measures of the fractional area occupied by grains normalized by the average area

of a single grain were a better estimate at high grain densities. The procedure can

be modified easily to operate on most image analyzers.. 0; 0; 0; 0.

233. Moe, G. W.; Howard, R. J.; Grima, E. A.; Armstrong, P. W. How does intermittent

pacing modify the response to rapid ventricular pacing in experimental heart

failure? J-Card-Fail. 1995 Jun; 1(3): 223-8; ISSN: 1071-9164.

UNITED-STATES. Rapid ventricular pacing is widely accepted as a useful

model to produce heart failure. The heart failure is associated with reduced

myocardial energy stores and absence of cardiac hypertrophy. In this study, it

was hypothesized that a modification of the protocol to intermittent pacing

would permit time for partial recovery of myocardial energetics leading to

improved cardiac function and development of hypertrophy. Eight dogs

underwent conventional continuous right ventricular pacing to a biologic endpoint

of severe heart failure (group 1). Another eight dogs underwent an intermittent

pacing protocol over 7 weeks, consisting of 48-hour pacing alternating with 24-

hour sinus rhythm (group 2) so as to produce the same total exposure to

continuous pacing as in group 1. Six additional normal dogs were used as control

animals for tissue metabolic data. Although both paced groups had similar

directional changes in hemodynamic, neurohormonal, and echocardiographic

variables, the absolute increases in pulmonary capillary wedge and right atrial

pressures in group 2 (13 +/- 8 and 3 +/- 4 mmHg, respectively) were less marked

than in group 1 (29 +/- 5 and 12 +/- 4 mmHg, respectively; both P = .002). Group

2 also had a more modest rise in plasma atrial natriuretic peptide and

norepinephrine concentrations. There was no significant increase, however, in left

ventricular mass in either group, and myocardial adenosine 5'-triphosphate levels

were reduced to a similar extent compared to the control animals. Intermittent

pacing produces a less advanced syndrome of heart failure than continuous pacing.

Furthermore, the data suggest that reduced energy stores are not the predominant

mechanism for impaired cardiac function, although they may contribute to the

failure to hypertrophy in this model.. 0; 114471-18-0; 85637-73-6.

234. Moffat, S. D.; Hampson, E.; Wickett, J. C.; Vernon, P. A.; Lee, D. H. Testosterone is

correlated with regional morphology of the human corpus callosum. Brain-Res.

1997 Sep 5; 767(2): 297-304; ISSN: 0006-8993.

NETHERLANDS. Theoretical speculation in humans (S.F. Witelson,

Psychoneuroendocrinology 16 (1991) 131-153) and empirical findings in animals

(R.H. Fitch, P.E. Cowell, L.M. Schrott, V.H. Denenberg, Int. J. Dev. Neurosci. 9

(1991) 35-38) suggest that testosterone (T) may play a significant role in the

development of the corpus callosum (CC). However, there are currently no

empirical studies directly relating T concentrations to callosal morphology in

humans. The purpose of the present study was to investigate the relationship

between free T concentrations as determined by radioimmunoassay, and the mid-

sagittal area of the corpus callosum, as determined by magnetic resonance imaging

(MRI). Subjects were 68 young adult (20-35 years), neurologically normal, right-

handed males. All subjects underwent MRI and provided two samples of saliva

for radioimmunoassay of T and cortisol. Anatomical regions of interest included

total brain volume, left and right hemisphere volume and regional areas of the CC.

CC regions were defined using two different measurement techniques, each

dividing the CC into six sub-sections. Anatomical measurements were performed

blind with respect to the hormone levels of subjects. A significant positive

correlation between T concentration and cross-sectional area of the posterior body

of the CC was found. This finding was consistent across the two measurement

techniques and was not attributable to individual differences in total brain volume.

All correlations between cortisol and CC sub-regions were non-significant. The

results of this study are consistent with the notion that T, at an earlier stage in

development, may play a significant role in modulating cortical/callosal

architecture in humans.. 50-23-7; 57-85-2.

235. Moffat, S. D.; Hampson, E.; Wickett, J. C.; Vernon, P. A.; Lee, D. H. Testosterone is

correlated with regional morphology of the human corpus callosum. Brain-Res.

1997 Sep 5; 767(2): 297-304; ISSN: 0006-8993.

NETHERLANDS. Theoretical speculation in humans (S.F. Witelson,

Psychoneuroendocrinology 16 (1991) 131-153) and empirical findings in animals

(R.H. Fitch, P.E. Cowell, L.M. Schrott, V.H. Denenberg, Int. J. Dev. Neurosci. 9

(1991) 35-38) suggest that testosterone (T) may play a significant role in the

development of the corpus callosum (CC). However, there are currently no

empirical studies directly relating T concentrations to callosal morphology in

humans. The purpose of the present study was to investigate the relationship

between free T concentrations as determined by radioimmunoassay, and the mid-

sagittal area of the corpus callosum, as determined by magnetic resonance imaging

(MRI). Subjects were 68 young adult (20-35 years), neurologically normal, right-

handed males. All subjects underwent MRI and provided two samples of saliva

for radioimmunoassay of T and cortisol. Anatomical regions of interest included

total brain volume, left and right hemisphere volume and regional areas of the CC.

CC regions were defined using two different measurement techniques, each

dividing the CC into six sub-sections. Anatomical measurements were performed

blind with respect to the hormone levels of subjects. A significant positive

correlation between T concentration and cross-sectional area of the posterior body

of the CC was found. This finding was consistent across the two measurement

techniques and was not attributable to individual differences in total brain volume.

All correlations between cortisol and CC sub-regions were non-significant. The

results of this study are consistent with the notion that T, at an earlier stage in

development, may play a significant role in modulating cortical/callosal

architecture in humans.. 50-23-7; 57-85-2.

236. Moller, H. E.; Vollmer Haase, J.; Wiedermann, D.; Schuierer, G. Localized proton

NMR spectroscopy in the striatum of patients with idiopathic spasmodic

torticollis. Magn-Reson-Med. 1998 Feb; 39(2): 309-12; ISSN: 0740-3194.

UNITED-STATES. Single voxel proton spectroscopy was used to study brain

metabolism in idiopathic spasmodic torticollis. Peak metabolite ratios in long echo

time (135 ms) spectra were evaluated in the basal ganglia of 16 patients (29-65

years). Eight of them were untreated; the other eight were examined 4-6 weeks

after administration of botulinum toxin type A. As compared with 60 control

spectra, patients showed a significant, therapy-resistant decrease in N-acetyl-L-

aspartate (NAA)/choline (Cho). NAA/creatine (Cr) and Cho/Cr were close to

normal in the post-treatment group but significantly reduced in untreated patients.

This result is consistent with the hypothesis that striatal Cr is reversibly elevated

in chronic muscle stimulation. The right and left striatum were affected to the

same extent.. 0; 0; 56-84-8; 57-00-1; 62-49-7; 997-55-7.

237. Morel, A.; Magnin, M.; Jeanmonod, D. Multiarchitectonic and stereotactic atlas of

the human thalamus. J-Comp-Neurol. 1997 Nov 3; 387(4): 588-630; ISSN: 0021-

9967.

UNITED-STATES. To improve anatomical definition and stereotactic precision

of thalamic targets in neurosurgical treatments of chronic functional disorders, a

new atlas of the human thalamus has been developed. This atlas is based on

multiarchitectonic parcellation in sections parallel or perpendicular to the standard

intercommissural reference plane. The calcium-binding proteins parvalbumin (PV),

calbindin D-28K (CB), and calretinin (CR) were used as neurochemical markers to

further characterize thalamic nuclei and delimit subterritories of functional

significance for stereotactic explorations. Their overall distribution reveals a

subcompartmentalization of thalamic nuclei into several groups. Predominant PV

immunostaining characterizes primary somatosensory, visual and auditory nuclei,

the ventral lateral posterior nucleus, reticular nucleus (R), and to a lesser degree

also, lateral part of the centre median nucleus, and anterior, lateral, and inferior

divisions of the pulvinar complex. In contrast, CB immunoreactivity is prevalent

in medial thalamic nuclei (intralaminar and midline), the posterior complex, ventral

posterior inferior nucleus, the ventral lateral anterior nucleus, ventral anterior, and

ventral medial nuclei. The complementary distributions of PV and CB appear to

correlate with distinct lemniscal and spinothalamic somatosensory pathways and

to cerebellar and pallidal motor territories, respectively. Calretinin, while

overlapping with CB in medial thalamic territories, is also expressed in R and

limbic associated anterior group nuclei that contain little or no CB. Preliminary

analysis indicates that interindividual nuclear variations cannot easily be taken

into account by standardization procedures. Nevertheless, some corrections in

antero-posterior coordinates in relation to different intercommissural distances are

proposed.. 0; 0; 0; 0.

238. Moser, E.; Diemling, M.; Baumgartner, R. Fuzzy clustering of gradient-echo

functional MRI in the human visual cortex. Part II: quantification. J-Magn-Reson-

Imaging. 1997 Nov; 7(6): 1102-8; ISSN: 1053-1807.

UNITED-STATES. Fuzzy cluster analysis (FCA) is a new exploratory method

for analyzing fMRI data. Using simulated functional MRI (fMRI) data, the

performance of FCA, as implemented in the software package Evident, was tested

and a quantitative comparison with correlation analysis is presented. Furthermore,

the fMRI model fit allows separation and quantification of flow and blood oxygen

level dependent (BOLD) contributions in the human visual cortex. In gradient-

recalled echo fMRI at 1.5 T (TR = 60 ms, TE = 42 ms, radiofrequency excitation

flip angle [theta] = 10 degrees-60 degrees) total signal enhancement in the human

visual cortex, ie, flow-enhanced BOLD plus inflow contributions, on average

varies from 5% to 10% in or close to the visual cortex (average cerebral blood

volume [CBV] = 4%) and from 100% to 20% in areas containing medium-sized

vessels (ie, average CBV = 12% per voxel), respectively. Inflow enhancement,

however, is restricted to intravascular space (= CBV) and increases with

increasing radiofrequency (RF) flip angle, whereas BOLD contributions may be

obtained from a region up to three times larger and, applying an unspoiled

gradient-echo (GRE) sequence, also show a flip angle dependency with a

minimum at approximately 30 degrees. This result suggests that a localized

hemodynamic response from the microvasculature at 1.5 T may be extracted via

fuzzy clustering. In summary, fuzzy clustering of fMRI data, as realized in the

Evident software, is a robust and efficient method to (a) separate functional brain

activation from noise or other sources resulting in time-dependent signal changes

as proven by simulated fMRI data analysis and in vivo data from the visual

cortex, and (b) allows separation of different levels of activation even if the

temporal pattern is indistinguishable. Combining fuzzy cluster separation of brain

activation with appropriate model calculations allows quantification of flow and

(flow-enhanced) BOLD contributions in areas with different vascularization.

239. Mullaney, P. B.; Jacquemin, C.; Abboud, E.; Karcioglu, Z. A. Tuberous sclerosis in

infancy. J-Pediatr-Ophthalmol-Strabismus. 1997 Nov; 34(6): 372-5; ISSN: 0191-

3913.

UNITED-STATES. PURPOSE: To report two infants with tuberous sclerosis

who initially were considered to have retinoblastoma. PATIENTS AND

METHODS: An 8-day-old infant was referred with small tumors in the posterior

poles of both eyes. A left microphthalmos with ciliochoroidal coloboma was

present. Computed tomographic (CT) scanning of the brain showed scattered

high-density subependymal foci in the lateral ventricle thought to be consistent

with calcification resulting from intrauterine viral infection. Argon laser

photocoagulation was applied to lesions in the right eye. Because one tumor was

situated on the retina straddling the coloboma in the left eye, external beam

radiotherapy was administered. A 5-month-old girl presented with a large mass in

a left microphthalmic eye. Calcification was present on B-scan ultrasonography

and CT scanning. Vitreous seeding was noted to originate from the tumor. The

contralateral eye manifested four small gray translucent retinal tumors in the

posterior pole. CT scan and magnetic resonance imaging (MRI) revealed multiple

periventricular subependymal lesions, including one at the foramen of Monro.

RESULTS: Repeated examinations in the younger child under anesthesia revealed

small new retinal lesions that appeared to enlarge gradually. She developed

intractable seizures and her electroencephalogram revealed a modified

hypsarrhythmia recording. A careful review of available CT scans and MRI

displays suggested the diagnosis of tuberous sclerosis. The child's most recent

examination under anesthesia revealed multiple newly developed hamartomas. In

the older child, prompt diagnosis was made on the basis of the intracranial

radiologic findings. CONCLUSION: Retinal hamartoma presentation may vary in

infancy. Small, initially fleck-like gliotic lesions appear to enlarge gradually and

eventually may form gray, translucent tumors. Large astrocytic hamartomas of the

retina associated with tuberous sclerosis may resemble retinoblastoma,

particularly if the mass is large, calcified, and associated with vitreous seeding.

Although ophthalmic presentation was reminiscent of retinoblastoma in both

patients, radiologic evidence of subependymal hamartomas pathognomic for

tuberous sclerosis helped establish the correct diagnosis. We stress the importance

of intracranial radiologic findings in this regard.

240. Nagaya, N.; Nishikimi, T.; Okano, Y.; Uematsu, M.; Satoh, T.; Kyotani, S.;