Sleep studies in benign epilepsy of childhood with rolandic spikes. II. Analysis of discharge frequency and its relation to sleep dynamics.

Polygraphic all-night sleep recordings of 11 children with benign epilepsy of childhood with rolandic spikes (BERS) were investigated from the viewpoint of spike distribution. Spike/min ratios were calculated with regard to different sleep stages and waking, identical stages of the consecutive cycles, and stages 1-2 taking place on the descending versus the ascending slopes of sleep cycles. Maximum spike/min ratios were related to slow sleep stages, especially delta sleep, and in general to the first cycle. Stages 1-2 on the descending (DESC) slopes of consecutive cycles showed a decrease in spike density during the night, as opposed to the increasing rate of activation of the same stages on the ascending (ASC) slopes. Based on our results, we suggest that the actual drive of spiking as well as seizures in BERS is the functional overweight of sleep-inducing mechanisms.