A phantom limb is the sensation that a limb is still there after amputation. For example, a patient whose leg has been amputated may still feel the itching of a foot that no longer exists, or feel that the leg is fixed at a certain angle. This sensation persists even though the limb itself is gone. In most patients, it turns into pain over time. This is called phantom limb pain.
The phantom limb was first described in the 16th century by the French surgeon Ambroise Paré. Paré observed that wounded soldiers still felt their amputated limbs. The term itself was coined in the 19th century by the American neurologist Silas Weir Mitchell. Mitchell examined soldiers wounded during the American Civil War and described the phantom limb in detail.
In Herman Melville's 1851 novel Moby Dick, Captain Ahab loses a leg to a whale. Ahab wears an ivory peg leg in its place. In one chapter, he tells the ship's carpenter that he can still feel his missing leg, as if it were still standing there invisibly. Melville wrote this description years before the term phantom limb entered medical language.
Phantom limb pain occurs in the great majority of patients who undergo arm or leg amputation. The pain usually begins shortly after amputation. In some patients, it can persist even years later. The intensity and character of the pain vary from person to person.
The mechanism underlying this phenomenon is not fully understood. However, a few explanations stand out. In the spinal cord and brain, the nerve connections that existed before the limb was severed remain active for some time. Each part of the body has its own map in the brain's cortex. When a limb is lost, the map for that region does not stay empty. The maps of neighboring regions expand into this empty space. This reorganization process may lead the brain to interpret the missing limb as if it were still there.
Changes also occur at the level of the spinal cord. Abnormal electrical activity can arise at the cut ends of nerves. This activity sends signals to the brain as if they were coming from a limb that no longer exists. The brain interprets these signals as pain.
Treating phantom limb pain is difficult and usually requires combining several methods. Medications used for neuropathic pain are used in drug treatment. These include certain antidepressants and seizure medications.
Among non-drug methods is mirror therapy. In this method, the image of the intact limb is reflected in place of the missing limb using a mirror. As the patient moves the intact limb, the brain perceives this movement as if it were happening in the missing limb. This misleading visual feedback reduces pain in some patients.
Nerve stimulation methods can also be used in treatment. Transcutaneous electrical nerve stimulation is one of these. In some centers, more invasive methods such as spinal cord stimulation are also tried. Good control of pain before amputation is thought to reduce the risk of phantom pain after surge
