- Last Updated on 14 December 2016
The vagal nerve stimulator (VNS) is an implanted device used to treat many types of epilepsy. There is very limited evidence to support treatment for infantile spasms, in particular, but it may nevertheless be of benefit. This device, which includes a tiny computer and battery pack, is surgically implanted in the upper left chest, with wires extending to the neck. The wires are attached to an important nerve in the neck, called the vagal nerve. By electrically stimulating the vagal nerve, with specific amounts of current and at varying duration and frequencies, seizure burden can often be significantly reduced. In addition, a special magnet can be waved above the device to deliver a temporary burst of added stimulation, in the effort to abort an ongoing seizure or stop a cluster of seizures. The exact mechanism by which VNS reduces seizures in not completely understood but likely involves functional changes in a part of the brain called the thalamus, which is known to be important in the propagation of seizures.