Event-related acoustically evoked potentials (ER-AEP) before and during anticonvulsive therapy in children

In this prospective study, 57 children, 6 to 15 years old, with the onset of a generalised epilepsy, symptomatic/cryptogenic focal epilepsy or idiopathic benign partial epilepsy were investigated before and during anticonvulsive therapy with valproic acid, carbamazepine and sulthiame. Before beginning the treatment, ER-AEP were performed and again three months later after starting medication. Control cohort was a group of 49 healthy children who also were investigated twice with ER-AEP without receiving any medication. For registration of the ER-AEP, sounds were presented to the children at random intervals in a ratio of 70 % of the stimuli at 1000 Hz and 30% of the stimuli at 4000 Hz. The children were instructed to indicate the 4000 Hz sounds. This was repeated at least three times for each patient to be sure of reproducibility. All data were analysed with parametric tests (paired t-test) and by analysis of variance (ANOVA) to find out their degree of significance. The median values of MMN and P300 were compared with those of the control group. Our study showed that primary generalised epilepsies did not lead to a significant prolongation of latencies, and that valproic acid did not have a significant effect. In symptomatic/cryptogenic focal epilepsies prolongation of latencies was found to be significant. Carbamazepine led to a significant improvement of latencies, and in idiopathic/benign partial epilepsy of childhood sulthiame even normalised the prolonged latencies. The prolongation of latencies is mainly located at the level between P2 and MMN. This investigation shows for the first time the influence of sulthiame on event-related potentials in idiopathic, so-called benign partial epilepsies in childhood.