Cyclic EEG changes in subacute spongiform and anoxic encephalopathy.

Polygraphic recordings of EEG, EMG, EKG and respiration were made on three patients with histologically verified subacute spongiform encephalopathy and one patient with anoxic encephalopathy both before and after intravenous diazepam. The records showed cyclical activity occurring about every half minute in which the EEG changes were correlated with myoclonus and cardio-respiratory changes. It is suggested that these cycles represent spontaneous cycles of arousal to which the 1/sec sharp waves are related wnd which result from the same mechanisms that produce other cyclical autonomic phenomena.