[Periodic EEG discharges of stereotyped morphology]

Clinical course of disease and results of EEG examinations of 6 patients with severe brain disturbances of various aetiology provided grounds for discussion on the phenomenon of periodic stereotyped EEG discharges (PSD) which is of considerable diagnostic value in some cases. The variability in appearance of these discharges, in their form and duration of intervals between them are stressed--the last parameter varied in own material from 0.5 to 8 sec. The appearance of PSD may indicate increased convulsive excitability of the cortical and subcortical structures of the gray matter. The prognostic value of PSD was not always the same and it could be established only basing upon a comparison of EEG findings during successive examinations.