[Effect of phenytoin and carbamazepine on evoked potentials in patients with newly diagnosed epilepsy. Part II. Brainstem auditory evoked potentials].

Brainstem auditory evoked potentials (BAEPs) were studied in 64 untreated epileptics with partial (58) and primary generalized seizures (6). Patients were randomized to have either phenytoin (PHT) or carbamazepine (CBZ) monotherapy. Follow-up recordings were made 3 months after PHT (21) or CBZ (22) monotherapy in 43 patients with partial seizures. Before treatment epileptic patients and controls did not differ in BAEPs results. All patients had therapeutic PHT or CBZ levels. PHT prolonged I-III and I-V interpeak latencies (IPL), and central conduction time (I-V) changes were correlated with the patients age. CBZ increased the latency of wave I and the central conduction time. The prolongation of I-III IPL was significant only for the group with partial secondarily generalized seizures and the III-V for the group with partial seizures without generalization. These results suggest similar effects of CBZ and PHT on BAEPs within serum therapeutic range.