Electroencephalographs Studies in Cerebrovascular Disorders

Abstract

Summary 1. The electroencephalograms of 23 vascular hemiplegias were studied. The classificaiton used here was as follows: normal or alpha with scattered theta, only theta in the involved hemisphere, small, moderate and large amounts of delta in the involved hemisphere. Using this classification, we found positive correlation between the degree of EEG abnormality and the severity of muscle weakness or mental abnormality. Furthermore, the EEG focus agreed with clinically suspected location of lesion. It also appeared that the longer the time after the cerebral ictus the less abnormal the EEG tended to be. Among 6 cases placed in the category of “normal or alpha with scattered theta,” only 2 manifested lower amplitude of less than 20 per cent difference in the involved region. Spikes or sharp waves were noted in 7 cases. 2. Serial EEG follow‐up was obtained in 7 patients. In general, EEG improvement coincided with clinical recovery. In 2 cases, however, clinical changes lagged behind the EEG improvement. 3. Among 10 subarachnoid hemorrhages, 4 were diffusely abnormal, 3 had foci coresrponding to the clinical location of lesion, and 2 without such agreement. The remaining one had normal EEG. Abnormalities demonstrated were spikes, sharp and slow waves. 4. Small numbers of cerebral arteriosclerosis were analysed. Among 12 of them, 9 had normal or borderline records and 2 showed abnormalities with spikes and or slow waves. The basic alpha rhythm of less than 10 cps was considered due to old age.