Vagus nerve stimulation (VNS) is a surgical operation for poorly controlled seizures, but does not involve surgery on the brain. A small pacemaker-like device is placed under the skin. This periodically stimulates the vagus nerve in the side of the neck with an electrical current, thus reducing seizure frequency and severity. The vagus nerve serves as one of many highways of information carrying messages to and from the brain. Nerve fibers in the vagus nerve relay information from the body's organs (such as the stomach and heart) to the brain. The vagus nerve has many connections to areas in the brain instrumental in producing seizures.
Recently, vagus nerve stimulation was approved as an adjunctive long-term treatment of chronic or recurrent depression for patients 18 years of age or older who are experiencing a major depressive episode and have not had an adequate response to four or more adequate antidepressant treatments.
In addition to treatment-resistant depression and drug-resistant epilepsy indications, VNS Therapy is at various stages of investigational clinical studies as a potential treatment for anxiety disorders, Alzheimer's disease, bulimia and chronic headache/migraine.
A device (generator) is implanted under the skin of the upper chest, in the depression between the left collar bone and the shoulder. It generates a small electric impulse that is delivered to the vagus nerve through fine wires (leads) that are tunneled to the neck to be attached to the nerve.
Surgery takes about a hour and is carried out on an outpatient basis.