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Vector analysis of pattern VEP
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+ MR, 4 cases of FIR, 1 case of MR without epileptic seizures for the last several years (MR + (Epy)) and 2 normal children were studied. Besides these, 2 cases of epilepsy without mental retardation (Epy) were examined. The ages of all cases ranged from 11 to 16 years. Natural sleep was recorded pol.vqraphicallv on two consecutive nights. Percentage of SPT (sleep period time) spent awake increased in the cases of Epy+MR. Percentage of SPT for slow wave sleep decreased markedly in the cases of EpytMR. Percentage of SPT for SREM decreased in the cases of MR+(Epy) and Epy+MR. REM density was lowered in the following order: the cases of normal + Epy + MR + Epy+MR. The difference of sleep pattern among the cases of normal, Epy and MR was not exhibited clearly, but severe sleep disturbance was shown in the cases of Epy +MR, implicating the severe brain damage to the cortex and the brain-stem. D-6.07 CLINICAL-EEG STUDY OF FOURTEEN AND SIX/ SEC POSITIVE SPIKES FOLLOWED BY SLOW WAVES. A. Hoshika, T. Matsuno, M. Ogihara, T. Miyajima, S. Aritaki, T. Honda, Y. Oana and S. Miura (Tokyo, Japan
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Fourteen and six/set positive spikes. are seen in the occipital and temporal areas, being immediately followed by slow waves occasionally. The authors classified the slow waves into 3 types, I: predominant in the frontal area, II: diffuse, and III: predominant in the occipital and temporal areas. This study was carried out on 21 cases in which these slow 'waves were observed. The chief complaints were autonomic sym ptoms (8 cases), convulsions (7 cases), problem behavior (4 cases) and asthma (2 cases). The patients, 11 boys and 10 girls, were 5 to 13 years old when these slow waves were recorded and children of 10 years were the largest in number (5 cases) among them. The slow waves were mostly seen in sleep Stage 1 and predominant on the side where 14 a 6/set positive spikes were predominant. The age when slow waves of the I and II types were apt to appear was 5 to 13 years, the age of the III type was Generalized spike-wave complex8 to 13 years. es or high voltage slow wave bursts were recognized in 8 cases (38.1%), focal spikes in 3 These abnormal EEGs suggest cases (14.3%). that the slow waves are caused by a subcortical disturbance. A-8.10 VECTOR chi, M. Toyoda
ANALYSIS OF PATTERN VEP. Y. Oguand I. Yamaguchi (Tokyo, Japan)
A method of vector analysis of visually evoked potentials by pattern reversal stimulation was The initial major vector component devised. acauired bv full-field stimulation for normal subjects showed a longitudinal and large one The stretching from anterior to posterior.
initial major vector component acquired by halffield stimulation was an ipsilateral and antero-posteriorly tilted vector. The vector analysis of VEPs obtained from 9 patients with hemianopsia was carried out. In 8 cases, the major vector component after full-field stimulation of one eye showed a direction which coincided with the results obtained from the halC field stimulation of the normal subject. However, in the left eye of one patient with left homonymous hemianoosia it was in the lonqitudinal direction for a while and then tilted right oosteriorlv. It is difficult to obtain vector VEPs when the visual acuity is very low and the residual visual field is severelv constricted. From this study, this method may be useful for detecting hemianopsia even in young children. A-11.02 THE FUNCTION OF SLEEP IN A HYPERBARIC HELIOX ENVIRONMENT (31ATA, 37 DAYS, 4 DIVERS). K. Seki, M. Matsuda, H. Nakayama (Yokosuka, Japan) and M. Hugon (Marseilles, France) Four test divers were exposed to a hyperbaric environment (He-02. PO2=0.4 bar, 32'C, SlATA) for 37 days, and all-night (23:00-07:OO) sleep profiles were recorded using polygraphy. Each day, the EEG, EOG, EMG, ECG, respiratory rate, rectal temperature and temperature of forehead skin were recorded. All-night sleep'profiles under 31ATA showed a remarkable increase in the awake time and total time of the REM period when compared with the pre-dive period (air, 1ATA). On the other hand, significant decrease in the total + IV) were sleep time and that of stages (III observed. The above mentioned chances in sleep parameters under the hyperbaric condition (31 ATA (HP-07)) were thouaht to be due not onlv to the hyber'baric condition but also to the He-0 itself. A significant decrease of the forehea 8 skin temperature (NREM period, 1ATA: 34.2oC, 31 ATA: 33.7oC, P
+ MR, 4 cases of FIR, 1 case of MR without epileptic seizures for the last several years (MR + (Epy)) and 2 normal children were studied. Besides these, 2 cases of epilepsy without mental retardation (Epy) were examined. The ages of all cases ranged from 11 to 16 years. Natural sleep was recorded pol.vqraphicallv on two consecutive nights. Percentage of SPT (sleep period time) spent awake increased in the cases of Epy+MR. Percentage of SPT for slow wave sleep decreased markedly in the cases of EpytMR. Percentage of SPT for SREM decreased in the cases of MR+(Epy) and Epy+MR. REM density was lowered in the following order: the cases of normal + Epy + MR + Epy+MR. The difference of sleep pattern among the cases of normal, Epy and MR was not exhibited clearly, but severe sleep disturbance was shown in the cases of Epy +MR, implicating the severe brain damage to the cortex and the brain-stem. D-6.07 CLINICAL-EEG STUDY OF FOURTEEN AND SIX/ SEC POSITIVE SPIKES FOLLOWED BY SLOW WAVES. A. Hoshika, T. Matsuno, M. Ogihara, T. Miyajima, S. Aritaki, T. Honda, Y. Oana and S. Miura (Tokyo, Japan
j
Fourteen and six/set positive spikes. are seen in the occipital and temporal areas, being immediately followed by slow waves occasionally. The authors classified the slow waves into 3 types, I: predominant in the frontal area, II: diffuse, and III: predominant in the occipital and temporal areas. This study was carried out on 21 cases in which these slow 'waves were observed. The chief complaints were autonomic sym ptoms (8 cases), convulsions (7 cases), problem behavior (4 cases) and asthma (2 cases). The patients, 11 boys and 10 girls, were 5 to 13 years old when these slow waves were recorded and children of 10 years were the largest in number (5 cases) among them. The slow waves were mostly seen in sleep Stage 1 and predominant on the side where 14 a 6/set positive spikes were predominant. The age when slow waves of the I and II types were apt to appear was 5 to 13 years, the age of the III type was Generalized spike-wave complex8 to 13 years. es or high voltage slow wave bursts were recognized in 8 cases (38.1%), focal spikes in 3 These abnormal EEGs suggest cases (14.3%). that the slow waves are caused by a subcortical disturbance. A-8.10 VECTOR chi, M. Toyoda
ANALYSIS OF PATTERN VEP. Y. Oguand I. Yamaguchi (Tokyo, Japan)
A method of vector analysis of visually evoked potentials by pattern reversal stimulation was The initial major vector component devised. acauired bv full-field stimulation for normal subjects showed a longitudinal and large one The stretching from anterior to posterior.
initial major vector component acquired by halffield stimulation was an ipsilateral and antero-posteriorly tilted vector. The vector analysis of VEPs obtained from 9 patients with hemianopsia was carried out. In 8 cases, the major vector component after full-field stimulation of one eye showed a direction which coincided with the results obtained from the halC field stimulation of the normal subject. However, in the left eye of one patient with left homonymous hemianoosia it was in the lonqitudinal direction for a while and then tilted right oosteriorlv. It is difficult to obtain vector VEPs when the visual acuity is very low and the residual visual field is severelv constricted. From this study, this method may be useful for detecting hemianopsia even in young children. A-11.02 THE FUNCTION OF SLEEP IN A HYPERBARIC HELIOX ENVIRONMENT (31ATA, 37 DAYS, 4 DIVERS). K. Seki, M. Matsuda, H. Nakayama (Yokosuka, Japan) and M. Hugon (Marseilles, France) Four test divers were exposed to a hyperbaric environment (He-02. PO2=0.4 bar, 32'C, SlATA) for 37 days, and all-night (23:00-07:OO) sleep profiles were recorded using polygraphy. Each day, the EEG, EOG, EMG, ECG, respiratory rate, rectal temperature and temperature of forehead skin were recorded. All-night sleep'profiles under 31ATA showed a remarkable increase in the awake time and total time of the REM period when compared with the pre-dive period (air, 1ATA). On the other hand, significant decrease in the total + IV) were sleep time and that of stages (III observed. The above mentioned chances in sleep parameters under the hyperbaric condition (31 ATA (HP-07)) were thouaht to be due not onlv to the hyber'baric condition but also to the He-0 itself. A significant decrease of the forehea 8 skin temperature (NREM period, 1ATA: 34.2oC, 31 ATA: 33.7oC, P