EFFECTS OF HIGH-DOSE ANTIEPILEPTIC DRUGS ON EVENT-RELATED POTENTIALS IN EPILEPTIC CHILDREN

N200 and P300 of event-related potentials (ERPs) were recorded from 22 epileptic children receiving high-dose antiepileptic drugs. The patie nts were undergoing monotherapy with supratherapeutic serum level and were not mentally retarded. P300 latency was prolonged in 5 of 8 patie nts (62.5%) of the carbamazepine (CBZ) group and in 4 of 7 patients (5 7.1%) of the phenytoin (PHT) group. Only one child of the PHT group sh owed abnormality in brain-stem auditory evoked potentials (BAEPs). Abn ormality of P300 was more frequent than that of BAEP. In patients of t he PHT group who underwent examinations consecutively before and after changing the dose, P300 latency was prolonged rapidly when the PHT le vel exceeded 30 mu g/ml. This suggested that the prolongation was dose dependent. In all patients of the valproic acid (VPA) group, P300 lat ency was normal. Only 2 patients of the PHT group had P300 prolongatio n simultaneously with clinical signs of intoxication. Others demonstra ted changes in P300 without symptoms of side effects.