EEG features of BRE include frequent spike and wave discharges in the centrotemporal region. The electrical field of epileptiform discharges is not widely distributed. Frequently, the dipole is tangentially located with positivity in the frontal regions. Characteristically, the spike is triphasic and blends into the after-coming slow wave. Commonly, epileptiform discharges occur in runs.
Unilateral discharges are more common.
Activating movements or eye opening does not block the discharges. Sleep, however, has a prominent activation on the epileptiform discharges. Over time the epileptiform discharges decrease and finally disappear at around 15 years. BRE appears to be a dominantly inherited condition with variable penetrance. It should be kept in mind that BRE is a syndromic diagnosis with the EEG forming an important component of the diagnosis.