Rhythmic slow activity in benign childhood epilepsy with centrotemporal spikes.

In benign childhood epilepsy with centrotemporal spikes (BCECT), focal rhythmic slow EEG activity is occasionally observed in the same region where the centrotemporal spikes or Rolandic Discharges (RD) are seen. This slowing appears especially when RDs are frequent. Holmes therefore hypothesized that these slow waves in BCECT were not the manifestations of structural lesion of the brain but secondary slowing accompanying RD. In order to clarify the origin of the slow activity, clonazepam was administered to four BCECT patients who had the focal slow waves. Clonazepam has recently been found by us to selectively diminish RD in BCECT. After the administration of clonazepam for 4 consecutive weeks, not only RDs but also the slow activity disappeared completely. This finding strongly suggests that these focal rhythmic slow waves in the same region of the RD are a part of the morphology of RD.