Vagus nerve stimulation

Vagus nerve stimulation (VNS) involves the electrical stimulation of the vagus nerve by an implanted device to stop seizures. The device itself consists of a pulse generator that is placed in the chest wall and electrodes that connect the generator to the vagus nerve. It is a relatively new treatment modality and is generally used for patients who’s seizures cannot be controlled by medication and do not have an epileptogenic lesion amenable to resection. Baseline stimulation runs through the device, and a wand can be waved over the device at the onset of a seizure or aura to help abort the seizure. New generators follow patterns in heart rate to sense an oncoming seizure and provide extra stimulation. VNS was first FDA approved for adults, but its indications have expanded in the past two decades, and approval has extended to children over the age of 12 as well as adults with refractory depression. Both children and adults have had significant seizure reduction and quality of life improvement from VNS implantation, including those with Lennox-Gastaut syndrome (LGS). This chapter will discuss the history, proposed mechanisms, indications, outcomes, and complications for VNS.