Vagal nerve stimulation (VNS)

Vagal nerve stimulation (VNS) requires surgical implant of a small pulse generator with a battery and a lead wire for stimulus. The device is implanted and its lead wires wrapped around the patient’s vagal nerve. The device is also approved for treatment of depression. The mechanism of action is unknown. Because it has diffuse involvement with neuronal circuits, there are a variety of mechanisms by which it may exert its effect on seizure control. VNS has been effective in treatment of partial onset seizures and has enabled reduction of drug therapy in some cases. It is an alternative for patients whose conditions have been refractory to multiple drugs and in those who are sensitive to the many adverse effects of antiseizure drugs and those who have difficulty adhering to medication schedules. However, VNS is a costly and invasive procedure.