Relationships between intelligence and electroencephalographic epileptiform activity in adult epileptics.

Intellectual correlates of electroencephalographic epileptiform activity were examined by administering the Wechsler Adult Intelligence Scale to epileptic patients divided into groups on the basis of presence or absence, average rate, and topographic distribution of discharges. The results showed that lower intelligence levels were associated with the presence of discharges, especially when they were generalized rather than focal and when they occurred at an average rate of more than one per minute. An examination of patients having discharges ipsilateral and contralateral to their handedness showed few findings, as did an analysis based on an assessment of strengths and weaknesses within individuals. The results suggest that electroencephalographic epileptiform activity is significantly related to the intellectual functioning of epileptics.