Impact of the novel anti-convulsant vigabatrin on functional recovery following brain lesion

GABAergic drugs can positively or negatively influence recovery of neurobeh avioral function following brain injury. Direct potentiation of GABA-mediat ed inhibition at the post-synaptic receptor (i.e., via GABA, muscimol, diaz epam, phenobarbital) after brain damage has been associated with impaired f unctional recovery. What remains unclear, however, is whether the mechanism of action by which GABA is augmented contributes to a drug's impact on the recovery process. Vigabatrin, a novel anti-convulsant that inhibits GABA-t ransaminase, was administered chronically after unilateral anteromedial cor tex lesions and recovery from somatosensory deficits assessed. In contrast to the direct GABA receptor agonists, vigabatrin did not adversely impact ( i.e., was neutral) recovery from neurobehavioral deficits at any of the ant i-convulsant doses tested. Measurable secondary drug effects like sedation and hypothermia diminished over time and were reversible upon drug disconti nuation. These results suggest that the degree to which a GABAergic agent i mpacts the recovery process after brain injury is dependent on the drug's m echanism of action.