What is Phantom Pain?
What is Phantom Pain?
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.
While phantom pain occurs most often in people who've had an arm or leg removed, the disorder may also occur after surgeries to remove other body parts, such as the breast, penis, eye or tongue. 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
Most people who have had a limb removed report that it sometimes feels as if their amputated limb is still there. This painless phenomenon, known as phantom limb sensation, can also occur in people who were born without limbs. Phantom limb sensations may include feelings of cold, warmth, itchiness or tingling — but should not be confused with phantom pain. Similarly, pain from the remaining stump of an amputated limb is not phantom pain. By definition, phantom pain comes from a body part that no longer remains.The sensation of pain from an amputated limb is the defining symptom of phantom pain. Characteristics of phantom pain include:
1) Onset within the first few days of amputation
Tendency to come and go rather than be constant
2) Seeming to come from the part of the limb farthest from the body, such as the foot of an amputated leg
3) May be described as shooting, stabbing, boring, squeezing, throbbing or burning
4) May be triggered by weather changes, pressure on the remaining part of the limb or emotional stress
The exact cause of phantom pain is unclear, but it appears to originate in the spinal cord and brain. During imaging scans — such as magnetic resonance imaging (MRI) or positron emission tomography (PET) — specific portions of the brain 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 spinal cord and brain lose input from the missing limb and adjust to this detachment in unpredictable ways. The result can mimic tangled wires and trigger the most basic message of the body that something is not right: pain. Studies also show that, after an amputation, the brain may re-map 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 also is 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.
Western Medicine Treatment
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 or transcutaneous electrical nerve stimulation (TENS). More-invasive options include injections or implanted devices. Surgery is done only as a last resort.
Although there are no medications specifically for phantom pain, some drugs designed to treat other conditions have been helpful in relieving nerve pain. Keep in mind that no single drug works for everyone, and not everyone benefits from medications. You may need to try several different medications to find one that works for you.
Antidepressants. Tricyclic antidepressants often can relieve the pain caused by damaged nerves. Examples include amitriptyline and nortriptyline (Pamelor). These drugs work by modifying chemical messengers that relay pain signals. Antidepressants may also help you sleep, which can make you feel better.
Anticonvulsants. Epilepsy drugs — such as gabapentin (Neurontin) and carbamazepine (Carbatrol, Tegretol) — are often used to treat nerve pain. They work by quieting damaged nerves to slow or prevent uncontrolled pain signals.
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 such as constipation or sedation.
As with medications, treating phantom pain with noninvasive therapies is a matter of trial and observation. The following techniques may relieve phantom pain:
Nerve stimulation. In a procedure called transcutaneous electrical nerve stimulation (TENS), a device sends a weak electrical current via adhesive patches on the skin near the area of pain. This may interrupt or mask pain signals, preventing them from reaching your brain.
Electric artificial limb. A type of artificial limb called a myoelectric prosthesis has motors controlled by electrical signals that occur during voluntary muscle activation in the remaining limb. Using a myoelectric prosthesis may reduce phantom pain.
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 stump. The person then performs symmetrical exercises, while watching the intact limb move and imagining that they are actually observing the missing limb moving. Studies have found that this exercise helps relieve phantom pain in a significant number of people.
Acupuncture. The National Institutes of Health has found that acupuncture can be an effective treatment for some types of chronic pain. In acupuncture, the practitioner inserts extremely fine, sterilized stainless steel needles into the skin at specific points on the body. It's thought that acupuncture stimulates your central nervous system to release the body's natural pain-relieving endorphins.
Minimally invasive therapies
Injections. Sometimes injecting pain-killing medications — local anesthetics, steroids or both — into the stump can provide relief of phantom limb pain.
Spinal cord stimulation. Your doctor inserts tiny electrodes along your spinal cord. A small electrical current delivered to the spinal cord can sometimes relive pain.
Intrathecal delivery system. This procedure allows medication to be delivered directly into the spinal fluid. Much lower doses of medication are needed with this route of delivery. It can be useful
for people who experience pain relief with oral medications but experience intolerable side effects.
Surgery may be an option if other treatments haven't helped. Surgical options include:
Brain stimulation. Deep brain stimulation, and motor cortex stimulation are similar to spinal cord stimulation except that the current is delivered within the brain. A surgeon uses a magnetic resonance imaging (MRI) scan to position the electrodes correctly. Although the data are still limited, brain stimulation appears to be a promising option in selected individuals.
Stump revision or neurectomy. If phantom pain is triggered by nerve irritation in the stump, surgical resection or revision can sometimes be helpful. But cutting nerves also carries the risk of making the pain worse.
Adopted from mayoclinic.com