[Clinical and EEG/ERP brain mapping studies with vigabatrin in therapy refractory epileptic patients]

In a single blind study the antiepileptic effects and safety of vigabatrin--a new anticonvulsant drug selectively inhibiting GABA-transaminase--was investigated in therapy resistant epilepsy, along with its central effects objectivated by mapping of EEG and event-related potentials (ERP). In addition to their current antiepileptic therapy, 10 patients with complex partial seizures (CP) (4 male, 6 female), aged between 22 and 57 years received placebo for 1 month, subsequently 2 g vigabatrin for 2 months and thereafter a titrated optimal dosage vigabatrin for another 2 months. Clinical investigations were carried out at the afore-mentioned periods, neurophysiological ones pre and post 2 months vigabatrin. After 2 months vigabatrin, 5 out of 10 patients had a 50% or greater decrease in CP frequency, after another 2 months 7 out of 10. The median number of CP per months decreased from 5.5 to 3.75 (p < 0.05) to 2.0 (p < 0.01), respectively. No clinically relevant side effects and laboratory changes were noted. EEG mapping showed decreased fast alpha and slow beta power and increased delta-theta frequency variability, reflecting most likely a decreased CP disposition. ERP mapping showed slightly increased N1 and P2 as well as reduced P300 amplitudes. Unchanged P300 latency indicated no delayed stimulus evaluation time after vigabatrin therapy.