One common reason to use a nerve stimulator is to treat chronic pain by stimulation of the spinal chord or the peripheral nervous system, according to WebMD. Another use for nerve stimulation is in the treatment of epilepsy through the stimulation of the vagus nerve, as explained by Mayo Clinic.
Doctors use nerve stimulation to treat pain when they believe that small pulses of electrical current might be effective at interfering with the existing nerve signals that are causing pain. Doctors first do a trial stimulation to determine if a patient's pain is responsive to nerve stimulation, and if this proves successful at reducing or removing discomfort, then they can implant a device under the skin. This device can either be connected directly to the nerves causing pain or implanted within the canal of the spinal column, according to WebMD. Another type of nerve stimulation for treating pain is transcutaneous electrical nerve stimulation or TENS. In this case the surface of the skin is stimulated either at the site of pain or at a pressure point.
Vagus nerve stimulation is used to treat epilepsy that has failed to respond to alternative treatments such as medication. Stimulation of the vagus nerve can reduce the frequency of seizures, states Mayo Clinic.