Published data suggest that patients who continue to experience seizures after trials of two or three AEDs are unlikely to become seizure-free with further attempts at pharmacotherapy. Such patients may experience poor quality of life and functional outcomes from continuing seizures and the adverse effects associated with further attempts at pharmacotherapy. VNS is a non-pharmacologic treatment for epilepsy with well-established effectiveness as an adjunctive treatment (to AEDs) for partial seizures refractory to AEDs, but there are no randomized clinical trials comparing the effectiveness of adjunctive VNS therapy with further pharmacotherapy alone in such patients.