Phantom Limb - Pain Relief
Written by Julie Taylor
Pain Relief for Phantom Limbs
The End The Pain Project, Moira-Judith Mann
Recently I (Julie) was introduced to a wonderful woman in Point Roberts, Washington where I learned about a condition that causes very real pain: the pain of a phantom limb. Whilst I was sad to learn of this offshoot of Princess Di's work with landmines, I was delighted to learn that her work was still being done and that the best treatment was affordable and beautifully practical. There's also an important application here for stroke victims...
Phantom limb pain is far too real, varied and rich to be explained by the random firings of a bruised nerve. People report not just pain but also sensations of sweatiness, heat, texture, and movement in a missing limb. There is no experience people have with real limbs that they do not experience with phantom limbs. They feel their phantom leg swinging, sweat trickling down a phantom arm, a phantom ring becoming too tight for a phantom digit (finger). Children have used phantom fingers to count and solve arithmetic problems."
The theory has begun to make sense of some bewildering phenomena. Among them is an experiment that Ramachandran performed with volunteers who had phantom pain in an amputated arm. They put their surviving arm through a hole in the side of a box with a mirror inside, so that, peering through the open top, they would see their arm and its mirror image, as if they had two arms.
Ramachandran then asked them to move both their intact arm and, in their mind, their phantom arm-to pretend that they were conducting an orchestra, say. The patients had the sense that they had two arms again. Even though they knew it was an illusion, it provided immediate relief. People who for years had been unable to unclench their phantom fist suddenly felt their hand open; phantom arms in painfully contorted positions could relax. With daily use of the mirror box over weeks, patients sensed their phantom limbs actually shrink into their stumps and, in several instances, completely vanish."
Dramatic success was the result of a randomized trial of mirror therapy for soldiers with phantom-limb pain recently published by researchers at Walter Reed Army Medical Center. More complete information might be available by contacting wramc.dci@ na.amedd.army.mil.
The new premise suggests that when an arm is amputated, nerve transmissions are shut off. The brain's ‘best guess' often seems to be that the arm is still there, but paralyzed, or clenched, or beginning to cramp up. It could feel like this for years. However, when the mirror box provides the brain with new visual input suggesting motion in the absent arm, the brain must incorporate the new information into its sensory map of what's happening, no matter how illusive. So the brain guesses again, and the pain vanishes.
According to Dr. Gawande, "The account of perception that's starting to emerge is what we might call the "brain's best guess" theory of perception: perception is the brain's best guess about what is happening in the outside world. The mind integrates scattered, weak, rudimentary signals from a variety of sensory channels, information from past experiences, and hard-wired processes, and produces a sensory experience full of brain-provided color, sound, texture, and meaning. We see a friendly yellow Labrador bounding behind a picket fence not because that is the transmission we receive but because this is the perception our weaver-brain assembles as its best hypothesis of what is out there from the slivers of information we get. Perception is inference.
Recently, Dr. Gawande met a man who caused him to wonder whether such phantom sensations are more common than thought.
Real-life stories:
"H. was forty-eight, in good health, an officer at a Boston financial-services company living with his wife in a western suburb, when he made passing mention of an odd pain to his internist. For at least twenty years, he said, he'd had a mild tingling running along his left arm and down the left side of his body, and, if he tilted his neck forward at a particular angle, it became a pronounced, electrical jolt. The internist recognized this as Lhermitte's sign, a classic symptom that can indicate multiple sclerosis, Vitamin B12 deficiency, or spinal-cord compression from a tumor or a herniated disk. An MRI revealed a cavernous hemangioma, a pea-size mass of dilated blood vessels, pressing into the spinal cord in his neck. A week later, while the doctors were still contemplating what to do, it ruptured.
"I was raking leaves out in the yard and, all of a sudden, there was an explosion of pain and my left arm wasn't responding to my brain," H. said when I visited him at home. Once the swelling subsided, a neurosurgeon performed a tricky operation to remove the tumor from the spinal cord. The operation was successful, but afterward H. began experiencing a constellation of strange sensations. His left hand felt cartoonishly large-at least twice its actual size. He developed a constant burning pain along an inch-wide ribbon extending from the left side of his neck all the way down his arm. And an itch crept up and down along the same band, which no amount of scratching would relieve.
H. has not accepted that these sensations are here to stay-the prospect is too depressing-but they've persisted for eleven years now.
He has tried all sorts of treatments-medications, acupuncture, herbal remedies, lidocaine injections, electrical-stimulation therapy. But nothing really worked, and the condition forced him to retire in 2001.
His neurologist introduced him to me, with his permission, as an example of someone with severe itching from a central rather than a peripheral cause. So one morning we sat in his living room trying to puzzle out what was going on.
He told me that he thought his problem was basically a "bad switch" in his neck where the tumor had been, a kind of loose wire sending false signals to his brain. But I told him about the increasing evidence that our sensory experiences are not sent to the brain but originate in it. When I got to the example of phantom-limb sensations, he perked up. The experiences of phantom-limb patients sounded familiar to him. When I mentioned that he might want to try the mirror-box treatment, he agreed. "I have a mirror upstairs," he said.
He brought a cheval glass down to the living room, and I had him stand with his chest against the side of it, so that his troublesome left arm was behind it and his normal right arm was in front. He tipped his head so that when he looked into the mirror the image of his right arm seemed to occupy the same position as his left arm. Then I had him wave his arms, his actual arms, as if he were conducting an orchestra.
The first thing he expressed was disappointment. "It isn't quite like looking at my left hand," he said. But then suddenly it was.
"Wow!" he said. "Now, this is odd."
After a moment or two, I noticed that he had stopped moving his left arm. Yet he reported that he still felt as if it were moving. What's more, the sensations in it had changed dramatically. For the first time in eleven years, he felt his left hand "snap" back to normal size. He felt the burning pain in his arm diminish. And the itch, too, was dulled.
"This is positively bizarre," he said.
He still felt the pain and the itch in his neck and shoulder, where the image in the mirror cut off. And, when he came away from the mirror, the aberrant sensations in his left arm returned. He began using the mirror a few times a day, for fifteen minutes or so at a stretch, and I checked in with him periodically.
"What's most dramatic is the change in the size of my hand," he says. After a couple of weeks, his hand returned to feeling normal in size all day long.
The mirror also provided the first effective treatment he has had for the flares of itch and pain that sporadically seize him. Where once he could do nothing but sit and wait for the torment to subside-it sometimes took an hour or more-he now just pulls out the mirror. "I've never had anything like this before," he said. "It's my magic mirror."
Dr. Gawande reported that there have been several isolated successes with mirror treatment.
"In Bath, England, several patients suffering from what is called complex regional pain syndrome-severe, disabling limb sensations of unknown cause-were reported to have experienced complete resolution after six weeks of mirror therapy."
Such findings opened up a intriguing speculation for Dr. Gawande.
"Perhaps many patients whom doctors treat as having a nerve injury or a disease have, instead, what might be called sensor syndromes. When your car's dashboard warning light keeps telling you that there is an engine failure, but the mechanics can't find anything wrong, the sensor itself may be the problem. This is no less true for human beings. Our sensations of pain, itch, nausea, and fatigue are normally protective. Unmoored from physical reality, however, these sensations can become a nightmare.
The mirror treatment targets the deranged sensor system itself. It essentially takes a misfiring sensor-a warning system functioning under an illusion that something is terribly wrong out in the world it monitors-and feeds it an alternate set of signals that calm it down. The new signals may even reset the sensor. "
Because I have come in contact with war amputees in Pakistan (Afghan refugees), Bosnia, Vietnam and Laos, as both a director/producer of refugee documentaries and as a writer, the article, ‘The Itch' by Dr. Atul Gawande, The New Yorker, June 30, 2008 was very encouraging to read. For it spelled out inexpensive and rapid methods to reduce or eliminate pain for phantom limb sufferers.
To reinforce his view, Dr. Gawande cited a phantom limb case study of V. S. Ramachandran, Director of the Center for Brain and Cognition at the University of California, San Diego. A woman who was born with only stumps at her shoulders has always felt herself to have arms and hands and even feels herself gesturing when talking.
According to Dr. Gawande, "The fallacy of reducing perception to reception is especially clear when it comes to phantom limbs. Doctors have often explained such sensations as a matter of inflamed or frayed nerve endings in the stump sending aberrant signals to the brain. But this explanation should long ago have been suspect. Efforts by surgeons to cut back on the nerve typically produce a brief period of relief followed by a return of the sensation.
The complete article, ‘The Itch' by Dr. Atul Gawande, The New Yorker, June 30, 2008, can be accessed at:
http://www.newyorker.com/reporting/2008/06/30/080630fa_fact_gawande
Judith Mann
July, 2008