Event-related potentials and cognitive functions in epileptic treated patients.

Antiepileptic drugs as well epilepsy itself are known to induce some cognitive impairment. Thirty-six epileptic patients under unchanged and reduced therapy conditions were followed from a clinical (seizures' evaluation, reaction times [RTs], memory tests) and neurophysiological (EEG, BAEPs, ERPs) point of view, weekly as inpatients (mean stay 8.9 weeks) and after 1 and 3 months as outpatients. This study showed on one hand no clear correlation between RTs and ERPs components, and on the other hand an improvement of the most complex RT after reduction of polytherapy or stabilization of seizures by the introduction of carbamazepine-CR in newly treated patients. These data suggest that in epileptic patients there exists a slowing of cognitive processes between the stimulus evaluation time and the motor response and that this step is improved when a reduced but efficient therapy is given.