Vagus Nerve Stimulation for Depression

Vagus nerve stimulation (VNS) is a long term, intermittent stimulation of the left vagus nerve (a major nerve originating from the brain) by a device. The device is commercially available from NeuroCybernetic Prosthesis (NCP). 

It is a watch-sized equipment that generates electric signals. It is implanted into the chest wall on the left side (like the pacemaker of the heart). Current is intermittently delivered through a lead wire from the equipment to stimulate the left vagus nerve. 

Vagus nerve stimulation has been used for the treatment of severe epilepsy for many years and it has been shown to be useful. However this has extended to the treatment of depression not responding to medications. 

The first implant was done in July 1998 at the Medical University of South Carolina in Charleston. Since then many patients have undergone such treatment for resistant depression.

The vagus nerve was chosen because it is a nerve originating from the brain that extends all the way down to the tummy. It carries electrical signals from internal organs to the brain. 

This information is transmitted to different parts of the brain, and has impact on the activity of the part of brain that controls emotion. The stimulation can be programmed by computer and can also be controlled manually by the patient.