Abstracts

Rationale: Vagal nerve stimulation is a relatively recent treatment option for controlling epilepsy. A response rate of approximately 40% was reported from initial clinical trials. In our experience, patients have a higher response rate than what has previously been reported in the literature.Methods: A retrospective descriptive analysis of 39 patients implanted with a Vagal Nerve Stimulator (VNS) from 1999 to 2006. The following data was collected: demographic characteristics, number of antiepileptic drugs tried prior to VNS, number of antiepileptic drugs used in combination with VNS therapy, VNS settings, and whether an inpatient epilepsy monitoring unit evaluation was performed prior to implantation.Results: Seventy-four percent of patients (29 of 39) reported an improvement of at least a 50% reduction in their seizure control. Many also reported a marked decrease in the duration and severity of both seizures and the post ictal period. This allows them to return to normal function quickly, which they were not able to do prior to VNS implantation. Twenty percent of patients (8 of 39) noticed no improvement. Most, but not all of these have epilepsy and other stigma of neurological dysfunction, such as intellectual impairment, Rhetts syndrome, and marked developmental delay. Two of three patients with inoperable brain tumors have improved. Data on 5 percent (2 of 39) patients was incomplete and did not allow us to evaluate their function.Conclusions: Seventy-four percent of patients (29 of 39) reported an improvement of at least a 50% reduction in their seizure control. Many also reported a marked decrease in the duration and severity of both seizures and the post ictal period. This allows them to return to normal function quickly, which they were not able to do prior to VNS implantation. Careful patient selection can improve the likelihood of successful VNS outcomes.