Randomized controlled pilot study of vigabatrin versus carbamazepine monotherapy in newly diagnosed patients with...

At present, 34 patients aged 15 to 63 years with newly diagnosed epilepsy have been randomly assigned to vigabatrin (n = 17) or carbamazepine (n = 17). Evaluation of clinical data, neuropsychological assessment, quantitative spectral electroencephalogram (EEG), and somatosensory- and visual-evoked potentials at baseline and after a 3 months' maintenance phase are presented for 12 patients on vigabatrin and for 11 patients on carbamazepine. Among these patients, retention rate in the maintenance phase of the study is 75% for vigabatrin patients (two noncompliant patients and one nonresponder dropped out) followed up for a mean of 11 months (range, 5 to 16 months). The retention rate for carbamazepine is 100% for the 11 patients, followed up for a mean of 9 months (range, 3 to 17 months). Patients receiving vigabatrin showed significant improvements in sustained concentration and tasks requiring flexible mental processing after the 3-month maintenance period, compared to baseline. In the carbamazepine group, there was improvement only in delayed list recall, and in contrast, errors in visuomotor tasks requiring processing increased significantly. Patients on carbamazepine demonstrated slowed occipital mean frequencies, but vigabatrin treatment was not associated with any significant quantitative EEG changes. Significant prolongation of somatosensory-evoked potential N19 latencies was seen with both carbamazepine and vigabatrin.