Topographical analysis of the centrotemporal discharges in benign rolandic epilepsy of childhood.

The onset, distribution, and spread of the average of 20 centrotemporal discharges for each of 10 patients with typical benign rolandic epilepsy of childhood (BREC) were examined using a computerized topographical mapping technique. A stereotypic dipole field was present along the rolandic region in all discharges. During its most prominent phase, the negative pole of the dipole was maximum at the centrotemporal region, with the positive pole involving the bifrontal region. A hypothesis is proposed that all discharges arise from a single generator which is oriented tangential to the surface. The generator is most likely situated in the lower rolandic region where the zero potential zone exists, between the frontal positivity and the centrotemporal negativity. Identification of this dipole configuration may be useful for differentiating BREC from focal epilepsy of other etiologies.