[Frequency pattern of alpha waves in the early stages of cerebrovascular circulation disorders].

In this study 201 EEG curves are interpreted belonging to patients suffering from incipient disturbances of the cerebral circulation. The patients were divided into 3 groups according to age (group I, 30-40 years; group II, 40-50 years; group III, 50 years and over). In group I there prevailed a rate of 11-12 alpha waves per sec., and a slower rate was hardly ever found; in group III the frequency pattern was quite different. This decreased frequency of the waves could be confirmed by statistics. We believe a direct link can be assumed to exist between a decrease in frequency and the beginning of disturbed cerebral circulation.