The phrase, “phantom limb”, was actually coined back in the days following the Civil War when thousands of soldiers had their limbs amputated yet still experienced mild to extreme pain or other sensations where their limbs had once been. This is still a common disorder today with as many as 50% – 80% of amputees experiencing strange sensations in their missing body part. While most phantom limb sensations occur in patients who have lost an extremity, such as an arm or a leg, it is not uncommon for patients to experience the same thing when a non-extremity has been removed. For example, I happen to have a friend who suffered from kidney cancer years ago. Surgeons removed the cancerous kidney and to this day she experiences a weird sensation in that area from time to time, as though her kidney is still there.
Causes of Phantom Limb Sensation
Phantom limb sensation was once believed to be a psychological issue, but now the cause is believed to be generated from the spinal cord and brain. When the body part is removed, normal nerve activity is disrupted. However, the nerve endings at the site of the amputation still send signals to the brain causing it to believe that the limb or other body part is still there. Other explanations include:
– Trauma to the nerves causing abnormal ectopic discharges that are perceived as pain.
– Scar tissue formation in the remaining portion of the limb or body part.
– Activation of the sympathetic nervous system, resulting in changes to synaptic responses.
– Physical memory of pain in the affected area prior to removal
Basically, the brain and spinal cord lose communication with the limb because it is no longer there, and then have to make adjustments that aren’t always predictable. This can cause confusion in the brain and spinal cord nerves while they try to re-route the information that was once sent to the amputated area.
Studies have also shown that the brain sometimes re-maps the amputated body part’s sensory pieces to another part of the body. For example, someone being touched on the cheek may also feel as though their missing foot is being touched as well.
Symptoms of Phantom Limb Sensation
Symptoms can occur in amputees as well as in people who have been born without the limb or body part. These symptoms include pain, burning, tingling, cramping, pins-and-needles, general aching, and even pleasure.
Not everyone experiences these phantom sensations, and not everyone experiences them for an extended amount of time. However, there are risk factors that increase a person’s chances for developing phantom limb sensations. These factors include:
– Pre-existing pain. If pain was present before the limb or body part was removed, then the patient has an increased chance of experiencing the phantom pain after it is removed.
– Blood clot in the amputated area.
– Infection in the amputated area.
– Previous spinal cord damage or damage to the nerves that supplied the affected amputated limb or body part.
– Adults are more likely to experience phantom sensations than children
There are no medications designed specifically for phantom pain, but some drugs can help in the treatment of nerve pain such as antidepressants, anticonvulsants, and narcotics. Electrical nerve stimulations has also been used to help manage sensations in some patients.
NYU Langone Medical Center