Vagus nerve stimulation is a procedure that stimulates the vagus nerve with electrical impulses. Vagus nerve stimulation can be used to treat epilepsy when other treatments haven't worked. Vagus nerve stimulation is also a treatment for depression, and it's being studied for conditions such as multiple sclerosis, migraine and Alzheimer's disease.There's one vagus nerve on each side of your body, running from your brainstem through your neck to your chest and abdomen.With vagus nerve stimulation, a device is surgically implanted under the skin on your chest. A wire is threaded under your skin connecting the device to the left vagus nerve. When activated, the device sends electrical signals along the vagus nerve to your brainstem, which then sends signals to certain areas in your brain.