Vocal cord adduction during vagus nerve stimulation for treatment of epilepsy

Left vagus nerve stimulation (VNS) was shown to reduce median seizure frequency by more than 50% in approximately 35 to 43% of patients with medically refractory partial seizures.1–3 VNS has been approved for use in the United States and in Europe as an adjunctive therapy in adults and adolescents older than 12 years of age with medically refractory partial onset seizures.4 Since 1988, approximately 5,000 patients worldwide have been treated with VNS. The stimulating electrodes are connected subcutaneously to a pulse generator in the left chest cavity. They deliver electrical stimuli bidirectionally to the left vagal nerve in the neck. Stimulation-related side effects are common and include voice alteration (as much as 66%), coughing (45%), pharyngitis (35%), throat pain (28%), and dyspnea (25%).1 These symptoms are mild or moderate in most cases and do not require a reduction in stimulation. Severe side effects or complications are rare. In our clinic, VNS has been performed in three patients with medically refractory epilepsy since March 1999. One patient experienced a strong stimulation-related dyspnea at day …