The latest news into the use of the Vagal Nerve Stimulator (VNS) to treat depression was reported to the Seventh World Congress of Biological Psychiatry.
The vagal or vagus nerve is one of the many nerves which carry messages to and from the brain. Nerve fibres in the vagal or vagus nerve carry information from the body’s organs to the brain and are connected to the area of the brain believed to be involved in producing seizures. It is suggested that stimulation of the vagal or vagus nerve may be able to disrupt epileptic activity.
The VNS is a pulse generator, similar to a heart pacemaker, inserted into an opening in the chest. The generator is linked, via an under-the-skin cable to an electrode inserted into an opening at the side of the neck.
This electrode is then fitted around the vagal or vagus nerve. The generator is then programmed to continuously stimulate the nerve at varying frequencies, typically for 30 seconds every 5 minutes. The frequency can be adjusted to the individual patient’s needs after the operation by the doctor, using a small magnet. Patients who experience an aura or warning before a seizure can also use this special magnet to manually activate the generator.
Researchers had studied the effect of the use of the VNS on patients with epilepsy and had noted that as well as reducing the number of seizures, it also "considerably brightened the patient's mood".
Cyberonics, who manufacture the VNS, are currently involved in a pilot scheme to test the use of the stimulator to treat depression.