Severe new seizures after initiation of vagus nerve stimulation therapy.

Vagus nerve stimulation is considered to be a safe and effective adjunctive therapy for patients with drug-resistant epilepsy. Contrary to some antiepileptic drugs, vagus nerve stimulation is not known to precipitate or aggravate new or preexisting seizures. We describe the emergence of a new type of disabling, recurrent partial seizure immediately after initiation of vagus nerve stimulation in a 51-year-old man with a known history of refractory partial epilepsy. Discontinuation of vagus nerve stimulation therapy and multiple antiepileptic drug interventions were required to abort these unexpected new seizures. We conclude that vagus nerve stimulation may induce paradoxical seizures, similarly to some antiepileptic drugs.