Phantom pain is the sensation of pain in a missing part of the body. It is most common in persons with an amputated limb, but can occur in patients with congenital missing limbs and spinal cord injury. Unlike psychosomatic pain, phantom pain appears to be a genuine physical sensation.
The cause of phantom pain is poorly understood. At first, it was thought that the brain was receiving pain impulses from damaged nerves which originally led to the missing parts. However, this theory cannot explain why persons who were born without a limb can experience phantom pain. Current theories concentrate on the role of the spinal cord in transmitting pain impulses as patients who have had their spinal cord completely severed have experienced phantom pain well below the injury site even though they have no control of their muscles and no sensation in the same area.
A new theory is that the brain is hard-wired to perceive the body as complete and that the sensation is actually entirely contained in the brain.
Phantom pain will respond to analgesics, but permanent relief is rare.