Phantom pain refers to the sensation of pain felt by patients who have had a limb amputated. The treatment of phantom pain is often disappointing and is unable to provide adequate relief to the patients. The area of the brain involved (posterior parietal cortex [PPC]) is found on the opposite side of the amputated limb. For example, if a patient has the right arm amputated, the left posterior parietal cortex is involved in the phantom pain.