Read about this puzzling condition that causes people to feel pain where a part of the body has been amputated. A number of treatments are available.
Phantom pain is pain that feels like it's coming from a body part that's no longer there. Doctors once believed this post-amputation phenomenon was a psychological problem, but experts now recognize that these real sensations originate in the spinal cord and brain.
Most people who've had a limb removed report that it sometimes feels as if the amputated limb is still there. This painless phenomenon, known as phantom limb sensation, isn't the same as phantom pain.
For some people, phantom pain gets better over time without treatment. For others, managing phantom pain can be challenging. You and your doctor can work together to treat phantom pain effectively with medication or other therapies.
Characteristics of phantom pain include:
The exact cause of phantom pain is unclear, but it appears to come from the spinal cord and brain. During imaging scans — such as magnetic resonance imaging (MRI) or positron emission tomography (PET) — portions of the brain that had been neurologically connected to the nerves of the amputated limb show activity when the person feels phantom pain.
Many experts believe phantom pain may be at least partially explained as a response to mixed signals from the brain. After an amputation, areas of the spinal cord and brain lose input from the missing limb and adjust to this detachment in unpredictable ways. The result can trigger the body's most basic message that something is not right: pain.
Studies also show that after an amputation the brain may remap that part of the body's sensory circuitry to another part of the body. In other words, because the amputated area is no longer able to receive sensory information, the information is referred elsewhere — from a missing hand to a still-present cheek, for example.
So when the cheek is touched, it's as though the missing hand is also being touched. Because this is yet another version of tangled sensory wires, the result can be pain.
A number of other factors are believed to contribute to phantom pain, including damaged nerve endings, scar tissue at the site of the amputation and the physical memory of pre-amputation pain in the affected area. A poorly-fitting prosthesis may also cause pain, though this is typically considered a cause of residual limb pain.
Not everyone who has an amputation develops phantom pain. Some factors that may increase your risk of phantom pain include:
Because the risk of developing phantom pain is higher for people who have experienced pain in the limb before amputation, some doctors recommend regional anesthesia (spinal or epidural) in the hours or days leading up to amputation. This may reduce pain immediately following surgery and reduce the risk of lasting phantom limb pain.
Although there's no medical test to diagnose phantom pain, doctors identify the condition based on your symptoms and the circumstances, such as trauma or surgery, which occurred before the pain started.
Describing your pain precisely can help your doctor pinpoint your problem. Even though it's common to have phantom pain and residual limb pain at the same time, treatments for these two problems may differ — so an accurate diagnosis is important.
Finding a treatment to relieve your phantom pain can be difficult. Doctors usually begin with medications and then may add noninvasive therapies, such as acupuncture.
More-invasive options include injections or implanted devices. Surgery is done only as a last resort.
Although no medications specifically for phantom pain exist, some drugs designed to treat other conditions have been helpful in relieving nerve pain. No single drug works for everyone, and not everyone benefits from medications. You may need to try different medications to find one that works for you.
Medications used in the treatment of phantom pain include:
Narcotics. Opioid medications, such as codeine and morphine, may be an option for some people. Taken in appropriate doses under your doctor's direction, they may help control phantom pain.
However, you may not be able to take them if you have a history of substance abuse. Even if you don't have a history of substance abuse, these drugs can cause many side effects, including constipation, nausea, vomiting or sedation.
N-methyl-d-aspartate (NMDA) receptor antagonists. This class of anesthetics works by binding to the NMDA receptors on the brain's nerve cells and blocking the activity of glutamate, a protein that plays a large role in relaying nerve signals.
In studies, NMDA receptor antagonists ketamine and dextromethorphan helped relieve phantom pain. Side effects of ketamine include mild sedation, hallucinations or loss of consciousness. No side effects were reported from the use of dextromethorphan.
As with medications, treating phantom pain with noninvasive therapies is a matter of trial and observation. The following techniques may relieve phantom pain for some people:
Mirror box. This device contains mirrors that make it look like an amputated limb exists. The mirror box has two openings — one for the intact limb and one for the residual limb.
The person then performs symmetrical exercises, while watching the intact limb move and imagining that he or she is actually observing the missing limb moving. Some studies, though not all, have found that this exercise may help relieve phantom pain.
Repetitive transcranial magnetic stimulation (rTMS). This therapy uses an electromagnetic coil placed against the forehead. Short pulses are sent through the coil that cause small electrical currents in the nerves located in a specifically targeted area of the brain.
Research suggests that this therapy may be helpful for phantom pain, though it isn't yet specifically approved for this condition. The magnetic field is similar to the one used in MRI scans. Side effects may include a mild headache or lightheadedness.
Surgery may be an option if other treatments haven't helped. Surgical options include:
Newer approaches to relieve phantom pain include virtual reality goggles. The computer program for the goggles mirrors the person's intact limb, so it looks like there's been no amputation. The person then moves his or her virtual limb around to accomplish various tasks, such as batting away a ball hanging in midair.
Although this technique has been tested only on a small number of people, it appears to help relieve phantom pain.
You may not have control over whether you develop phantom pain after surgery, but you can reduce your discomfort and improve your quality of life. One or more of these approaches may help you get through a flare-up of phantom pain:
Remember that managing phantom pain can make a big difference in how you feel. If one approach doesn't provide relief, try something else rather than give up.
Learning to live without a limb, especially if you have phantom pain, can be challenging. Depression often accompanies pain. You may find it helpful to talk to a counselor or therapist.
An in-person or online support group can put you in touch with others who know what you're going through. To find support, ask your doctor for a referral, either to a counselor or to a support group.
You can also contact the Amputee Coalition at www.amputee-coalition.org for information on its National Peer Network, which can put you in touch with a variety of support services, including its Peer Visitor Program. This program can connect you with someone who's been in your place and can talk to you about healing, share his or her experiences, and offer advice.
June 11th, 2021
