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Subclinical movement disorders in young schizophrenics
S58
B-4.05
TICITY.
THE COMPOSITE la EPSP IN HUMAN SPASP. Ashby and J. Somerville (Toronto,
Canada) Postsynaptic events in single neurons can be derived from cross correlations between, the timing of afferent volleys and the discharges of the neuron when it is firing rhythmically. In normal subjects and in patients with spasticity, when homonymous group 1 volleys are delivered to rhythmically discharging soleus motor units the cross correlations show a period of increased firing probability related to the rising phase of the composite la EPSP. This is followed by a period of decreased firing probability which is partly compensatory and partly the effect of inhibitory interneurons. We found no increase in the rise time or relative amplitude of the composite la EPSP in patients with spasticity. There was a significant reduction in the duration of the period of decreased firing probability. Thus, there may be alterations of interneuronal activity in spasticity. B-11.06 VISUAL CORTICAL MONKEY. D.C. Van Essen
AREAS IN THE MACAQUE (Pasadena, Cal., USA)
Visually responsive cortex in the macaque monkey occupies all of the occipital lobe plus large portions of temporal and parietal cortex. Within. this region ten distinct visual areas have been identified to date on the basis of their architecture, connections, function, and topographic organization. Seven of these areas contain topographically organized representations of the visual field, but in some areas the representation is either incomplete or With the aid of two-dimenlocally disorderly. sional, unfolded maps of the cortex it is possible to make accurate determinations of the size of different areas and of their pattern of interconnections. Single-unit functional studies have demonstrated a very high incidence of direction-selective cells in MT. the middle temporal area, suggesting that this area mayplay an important role in the analysis of moving stimuli. In area V4 a substantial minority of cells is selective for stimulus color. Since V4 is a principal target of V2 and a principal source of inputs'to inferotemproal cortex,it seems likely that this area also is imoortantlv involved in processing information about stimulus form. The degree to which specific visual functions can be assigned to other extrastriate visual areas is largely unknown. C-1.06 SUBCLINICAL MOVEMENT DISORDERS IN YOUNG SCHIZOPHRENICS. I. Lehtinen, R. Salokangas, E. Syvalahti, J.P. Halonen and T. Nyrke (Turku, Finland) Smooth pursuit logical tremor
eye movements, saccades, physioand sleep EEG (with body move-
ment detection) have been studied in 11 young, neurologically healthy, schizophrenic patients. In this pilot study the measurements were performed after two week's standardized treatment with neuroleptics (perphenazine or chlorpromazine) to reveal latent disorders of saccades, smooth pursuit eye movements, physiological tremor or body mobility during sleep and correlate these changes with clinical findings and occurrence if the beta mitten pattern in sleep EEG. The movement tests were repeated after one week's additional treatment with biperiden. Smooth pursuit eye movements were grossly irregular in 3/10 patients and 3 more showed periodic abnormalities due to attentional factors. Those with irregular smooth pursuit funztion also had abnormal saccades and lower peak frequency of physiological tremor. Small changes in movement parameters could be detected after biperiden treatment. A larger group of patients in addition to the pilot group is currently being studied in order to test if the subclinical movement disorders could be used in prediction of the development of tardive dyskinesia after neuroleptic treatment. D-4.02 NEUROGRAPHIC EVIDENCE IN ALCOHOLIC NEUROPATHY. D. Kountouris, M.E. Dughly, J. Haan and J. Elilonas (Bochum, W. Germany) The motor nerve conduction velocities of n. medianus, n. ulnaris, n. tibialis and n. peronaeus were compared with the nerve conduction velocities measured after the definition of the shortest F wave latency in the same nerves in 62 subiects with alcoholic neurooathv of different-degrees and in 81 healthy'persons. The sensory nerve conduction velocities of n. suralis as well as the form and size of the F wave amplitude of the motor sum potentials and the sensory nerve action potentials were examined and compared in the groups of healthy and alcoholic persons. The results showed that the average nerve conduction velocity, defined through the F waves, was lower in comparison to the motor nerve conduction velocity in all 4 nerves in the alcoholic subjects. It was also remarkable that in the 39 alcoholic persons, when a low sensory nerve conduction velocity of n. suralis was found, the difference between the motor nerve conduction velocity and the nerve conduction velocity defined through the F waves in the other 4 nerves was most evident. The amplitudes of the F waves, the motor sum potentials and the sensory nerve action potentials were lower in the alcoholic subjects than in the healthy ones.
B-4.05
TICITY.
THE COMPOSITE la EPSP IN HUMAN SPASP. Ashby and J. Somerville (Toronto,
Canada) Postsynaptic events in single neurons can be derived from cross correlations between, the timing of afferent volleys and the discharges of the neuron when it is firing rhythmically. In normal subjects and in patients with spasticity, when homonymous group 1 volleys are delivered to rhythmically discharging soleus motor units the cross correlations show a period of increased firing probability related to the rising phase of the composite la EPSP. This is followed by a period of decreased firing probability which is partly compensatory and partly the effect of inhibitory interneurons. We found no increase in the rise time or relative amplitude of the composite la EPSP in patients with spasticity. There was a significant reduction in the duration of the period of decreased firing probability. Thus, there may be alterations of interneuronal activity in spasticity. B-11.06 VISUAL CORTICAL MONKEY. D.C. Van Essen
AREAS IN THE MACAQUE (Pasadena, Cal., USA)
Visually responsive cortex in the macaque monkey occupies all of the occipital lobe plus large portions of temporal and parietal cortex. Within. this region ten distinct visual areas have been identified to date on the basis of their architecture, connections, function, and topographic organization. Seven of these areas contain topographically organized representations of the visual field, but in some areas the representation is either incomplete or With the aid of two-dimenlocally disorderly. sional, unfolded maps of the cortex it is possible to make accurate determinations of the size of different areas and of their pattern of interconnections. Single-unit functional studies have demonstrated a very high incidence of direction-selective cells in MT. the middle temporal area, suggesting that this area mayplay an important role in the analysis of moving stimuli. In area V4 a substantial minority of cells is selective for stimulus color. Since V4 is a principal target of V2 and a principal source of inputs'to inferotemproal cortex,it seems likely that this area also is imoortantlv involved in processing information about stimulus form. The degree to which specific visual functions can be assigned to other extrastriate visual areas is largely unknown. C-1.06 SUBCLINICAL MOVEMENT DISORDERS IN YOUNG SCHIZOPHRENICS. I. Lehtinen, R. Salokangas, E. Syvalahti, J.P. Halonen and T. Nyrke (Turku, Finland) Smooth pursuit logical tremor
eye movements, saccades, physioand sleep EEG (with body move-
ment detection) have been studied in 11 young, neurologically healthy, schizophrenic patients. In this pilot study the measurements were performed after two week's standardized treatment with neuroleptics (perphenazine or chlorpromazine) to reveal latent disorders of saccades, smooth pursuit eye movements, physiological tremor or body mobility during sleep and correlate these changes with clinical findings and occurrence if the beta mitten pattern in sleep EEG. The movement tests were repeated after one week's additional treatment with biperiden. Smooth pursuit eye movements were grossly irregular in 3/10 patients and 3 more showed periodic abnormalities due to attentional factors. Those with irregular smooth pursuit funztion also had abnormal saccades and lower peak frequency of physiological tremor. Small changes in movement parameters could be detected after biperiden treatment. A larger group of patients in addition to the pilot group is currently being studied in order to test if the subclinical movement disorders could be used in prediction of the development of tardive dyskinesia after neuroleptic treatment. D-4.02 NEUROGRAPHIC EVIDENCE IN ALCOHOLIC NEUROPATHY. D. Kountouris, M.E. Dughly, J. Haan and J. Elilonas (Bochum, W. Germany) The motor nerve conduction velocities of n. medianus, n. ulnaris, n. tibialis and n. peronaeus were compared with the nerve conduction velocities measured after the definition of the shortest F wave latency in the same nerves in 62 subiects with alcoholic neurooathv of different-degrees and in 81 healthy'persons. The sensory nerve conduction velocities of n. suralis as well as the form and size of the F wave amplitude of the motor sum potentials and the sensory nerve action potentials were examined and compared in the groups of healthy and alcoholic persons. The results showed that the average nerve conduction velocity, defined through the F waves, was lower in comparison to the motor nerve conduction velocity in all 4 nerves in the alcoholic subjects. It was also remarkable that in the 39 alcoholic persons, when a low sensory nerve conduction velocity of n. suralis was found, the difference between the motor nerve conduction velocity and the nerve conduction velocity defined through the F waves in the other 4 nerves was most evident. The amplitudes of the F waves, the motor sum potentials and the sensory nerve action potentials were lower in the alcoholic subjects than in the healthy ones.