Abstracts

RATIONALE: To study the effect of VNS on seizure reduction in patients with intractable temporal lobe epilepsy with bilateral independent temporal lobe foci. METHODS: We retrospectively reviewed charts of patients with medically refractory epilepsy who had VNS implanted. Seven consecutive patients with bilateral independent temporal lobe epilepsy were identified and followed for 4-15 months. This diagnosis required the presence of two distinctive clinical and ictal EEG seizure patterns recorded either by only scalp (4 subjects) or scalp and depth electrodes (3 subjects). We studied the following variables: age of seizure onset, seizure etiology, seizure types, MR findings, seizure frequencies 1 year before VNS implantation up to the time of last follow up and the number of antiepileptic medications before and after VNS implantation. Adverse events and general well-being after VNS implantation were also recorded. RESULTS: Four subjects with only partial seizures without secondarily generalization before implantation (57%) reported > 50% reduction in their seizure frequencies, 3 subjects reported no reduction in their partial seizures. However 2 of these subjects who had partial seizure with and without secondarily generalization were no longer having convulsions since VNS implantation. Adverse events were reported in two patients, one reported hoarseness, the other one general discomfort. Two patients reported improved alertness and less depression after the VNS was implanted. Only one subject was able to decrease antiepleptic medications successfully. CONCLUSIONS: VNS is effective and well tolerated in this select group of intractable epilepsy patients.