Effects of long term vigabatrin on somatosensory evoked potentials in epileptic patients.

1. Vigabatrin has proved to be a very effective antiepileptic in clinical trials, with excellent long term tolerability. 2. The purpose of this study was to test the central nervous system (CNS) safety of the drug during long term clinical use, due to the existence of species-dependent intramyelinic oedema in animal toxicology studies. 3. Somatosensory evoked potentials were recorded repeatedly over a mean period of 11 months, in 54 adult patients with refractory epilepsy who received vigabatrin as add-on therapy to their current antiepileptic regime. 4. There was no suggestion throughout the study that vigabatrin could lead to a prolongation of neuronal conduction times within the CNS pathways. 5. The results are consistent with previous studies of somatosensory, visual and brainstem auditory evoked potentials in patients. In view of the results observed in the dog, where increases in central latencies of somatosensory evoked potentials were clearly apparent, these data provide strong reassurance about the neurological safety of vigabatrin in the treatment of epileptic patients.