Phantom Limb Pain: Cause, Effect, And Treatment
Phantom limb pain is a strange condition occurring in individuals after limb amputation or in those born without a particular limb. Patients who suffer nerve damage or paralysis may also be afflicted. Despite the amputation, the patient feels pain located in the limb itself, not in the stump, which theoretically would be impossible given that the limb has been removed.
Burning pain or other symptoms in missing limbs is quite common, with 60 to 80% of amputees experiencing these phantom sensations; incidence rates depend on the location of the amputation. The pain may develop immediately after surgery or may appear a few weeks after.
While the exact mechanism that causes phantom limb pain is uncertain, doctors have suggested a few possible causes.
According to the most common theory, the nerve endings remaining in the stump continue transmitting impulses to the brain, which believes that the limb is still attached and interprets these signals as pain.
The latest theories push the source of the sensations away from the stump toward the brain itself. They downplay the role of local nerves and instead champion cortical remapping and “neuromatrix” theories that incorporate a whole-body, whole-brain approach by locating the cause of the phantom pain in the rewiring of the entire neural system after amputation.
Signs and Symptoms
Patients report feeling sensations ranging from mild pain and discomfort to extreme pain in the phantom limb. The type of pain varies. Some report “burning pain” or “aching” sensations; one patient claimed he felt “as if the hand is being crushed in a vice.”
Sufferers may also report other symptoms, including tingling, sensations of heat and cold, itching, and cramps. If the individual had been feeling other sensations in the limb before it was amputated, these feelings may persist long after the appendage is removed.
This chronic pain may come and go and change in type and intensity over time.
For many sufferers, pain attenuates over time. However, if these feelings don’t disappear after six months, the chances for further improvement are decreased. The optimal strategy for treating the condition depends on the patient’s exact symptoms. Pain management doctors typically combine one or more of the following treatments:
- Applying heat to the area
- Massage & relaxation techniques
- Biofeedback strategies to lower muscle tension
- Physical therapy with mirror box therapy
- Additional surgery to remove any scar tissue interfering with nerve function
- transcutaneous electrical nerve stimulation (TENS) of the amputation area or neurostimulation of the spinal cord or brain
- Medications to manage and relieve pain
- Other drugs like beta-blockers, antidepressants, and neuroleptics
Pain management doctors continue to innovate in their efforts to ameliorate the condition. One of the newer treatments is to decrease pain by using electrical prosthetic limbs to simulate the control of the brain over the phantom limb.
In another treatment, the patient puts his or her remaining arm into a mirror box to create a mirror image illusion of the missing limb. When the patient moves this “restored” limb, pain sensations diminish. Virtual reality treatment to simulate movement of the limb has also shown some promise.