Benign rolandic epilepsy: high central and low central subgroups.

The spikes in benign rolandic epilepsy (BRE) typically involve both the central and midtemporal regions as recorded on standard EEG montages, but the seizures are characterized by sensorimotor manifestations that are rarely referrable to the temporal lobe. To study this apparent disparity, we evaluated the field distribution of interictal spikes in 33 BRE patients using closely spaced electrodes (AEEGS 1990) arranged over perisylvian cortex. None of the 33 patients showed maximum negativity in the midtemporal regions (T3/T4). Instead, maximum negativity was evident in the high central region (C3/C4) in 10 children (30.3%) and in the low central region (C5/C6) in 23 (69.7%). Hand involvement was significantly frequent (50%) in the high central group, and drooling with oromotor involvement was a distinctive symptom (65.2%) in the low central group. Our findings indicate that the spikes in patients with BRE are exclusively suprasylvian in origin and correlate with two electroclinical subgroups.