Grey's Anatomy character Dr. Arizona Robbins, played by actress, has had a rough year.
Although she survived a plane crash which killed two other physicians, the pediatric surgeon had a terrible leg wound, which ultimately lead to a leg amputation. And just as things started to look up for Arizona -- she has accepted a prosthetic limb and returned to work -- she's been plagued by another problem: phantom limb pain. As Dr. Meredith Grey (Ellen Pompeo) says in her opening voice-over:
"Patients who undergo amputation often feel sensation where the missing limb was, as if it's still there. The syndrome is called phantom limb. It's as if the body can't accept that a terrible trauma has occurred. The mind is trying to make the body complete again. Patients who experience phantom limb report many different sensations, but by far the most common is .. .pain."At one point, the pain is so severe that Arizona asks assistant surgeon, Alex Karev, to to relieve the pain. She eventually confides to surgical chief Owen Hunt (Kevin McKidd) that she thinks she is going crazy, but he recognizes the problem from his military service and will help her find therapies that may make things easier. <乌鸦传媒>What is phantom limb pain?
After a limb is amputated, a patient may feel as if the limb is still there. This is called phantom sensation. It may feel:
- Tingly
- Prickly
- Numb
- Hot or cold
- Like the missing toes or fingers are moving
- Like the missing limb is still there, or is in a funny position
- Like the missing limb is getting shorter. This is called telescoping.
It is estimated that between 60-80% of patients who have experience an amputation experience phantom sensations in their amputated limb, and the majority of the sensations are painful.
Phantom pain occurs within a few days of amputation in 75% of patients, but can begin months, to even years, later.
<乌鸦传媒>What causes phantom limb pain? Theories concerning the cause of phantom limb pain (PLP) have evolved over time. PLP was initially thought to be a psychological problem related to the psychic trauma of limb loss.
Later theories asserted that the pain was real, but was probably related to changes which originated at the site of the amputation. Irritation of the severed nerve endings, called neuromas, sent abnormal signals to the brain which were interpreted as pain. This sometimes led to surgery to revise the stump in the hope of eliminating the pain, but the surgery often was unsuccessful.
More recent theories indicate that there are a number of factors that produce PLP. There are elements in the periphery and at the spinal cord level, but the major component may originate in the brain itself.
Using studies in primates and noninvasive imaging techniques such asand , researchers now believe that PLP sensations are due to the brain’s attempt to reorganize sensory information following the amputation. The brain is "rewiring itself” to adjust to the body change. This is referred to as .
According to L. Nikolajsen and T. S. Jensen in the:
"Electrophysiological studies have documented the existence of nociceptive specific neurons and wide dynamic range neurons in the cerebral cortex. Following limb amputation and deafferentation of adult monkeys, there is a reorganization of the primary somtosensory cortex, subcortex and thalamus ... In humans, similar reorganization has been observed using magnetoencephalographic techniques."<乌鸦传媒>What is the course of phantom limb pain? Phantom sensations typically get weaker and happen less frequently slowly over time. Although phantom limb pain will lessen over time for most people, it may not ever go away completely. <乌鸦传媒>How is phantom limb pain treated? Finding a treatment for PLP can be difficult. There is no specific medication to treat it, although some medications, such as antidepressants, anticonvulsants, and some narcotics may decrease symptoms. Some noninvasive therapies have also become available:
- Transcutaneous electrical nerve stimulation (TENS): a device sends a weak electrical current across the skin near the area of pain using adhesive patches on the skin.
- An artificial limb called a
- A mirror box: developed by and colleagues, uses a mirror to create artificial visual feedback. Looking into the box, the patient becomes able to "move" the phantom limb, and to unclench it from potentially painful positions. Repeated training in some subjects has led to long-term improvement. Here's a video to show how it works:
Recently, (which may incorporate mirror therapy) and sensory discrimination training have emerged as promising therapeutic tools in dealing with pathological pain problems such as phantom limb pain and complex regional pain syndrome. <乌鸦传媒>Who cares about phantom limb pain in a TV character? Although Arizona Robbins may be fictional, the issue she is dealing with is very real, and very important.
Just think about how many servicemen and women have sustained injuries that required amputation over the past 11 years. According to the from 2000 to 2011, there were 6,144 cases of traumatic amputations among 5,694 service members. And according to the , the Department of Defense reported that the number of U.S. troops who lost limbs reached a wartime high in 2011.
This doesn't even scratch the surface of the potential magnitude of the problem -- what about those who have had amputations because of accidental trauma, diabetes, heart disease. infections, or cancer?
More research is necessary to clarify the causes of PLP and to develop effective therapies. Clinical trials underway at at the National Institutes of Health can be found by clicking .
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