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A Mirror as Medicine
The most intriguing cam therapy is the newest. It's called mirror therapy. Well over half of amputees suffer from phantom-limb pain because, roughly speaking, their brains are confused. The motor-command center in the frontal lobe doesn't register that a limb (or an ear or the nose) is gone. Consequently, it keeps sending nerve signals down the spine to the appendage. These signals can't be received, of course, and the missing body part can't transmit its customary neuronal cues back to the brain. The brain then responds by firing "pay attention to me" signals in its areas that control the arms or legs or ear and so on. These signals are interpreted as pain in the phantom limb.
Phantom-limb pain was recognized at least as far back as the 1870s, when many Civil War veterans complained that they were disturbed by "sensory ghosts." Few treatments other than great gobs of opiates existed for phantom-limb pain until Vilayanur Ramachandran, a neuroscientist at the University of California, San Diego, took an interest in the subject a few years ago. And few neurologists and psychiatrists paid attention to Ramachandran's work until thousands of U.S. service members began returning from Afghanistan and Iraq without all their limbs.
As Ramachandran writes in his new book, The Tell-Tale Brain: A Neuroscientist's Quest for What Makes Us Human, when an arm is amputated, "there is no longer an arm, but there is still a map of the arm in the brain. The job of this map, its raison d'être, is to represent its arm. The arm may be gone; but the brain map, having nothing better to do, soldiers on."
And so, in order to treat chronic phantom pain, one must trick this map into believing that a new road has been constructed. Because they deaden the senses, pain medications are the worst way to construct a new map. Psychotherapies — particularly mindfulness-based practices that urge patients to accept that they have lost a limb and learn to live without it — can change the brain's map over weeks or months through rigorous cognitive therapy combined with behavioral therapy that focuses on recognizing that a limb is missing and strengthening other parts of the body to compensate.
But Ramachandran devised a way to trick the brain much more efficiently. Struck by the simplicity of his theory that phantom-limb pain was merely a symptom of brain confusion, Ramachandran reasoned that if the brain could be convinced the missing limb still existed, the central pain resulting from its loss would ease. So he placed an upright mirror between the two "hands" or two "legs" of an amputee. He faced the reflecting side of the mirror toward the whole hand — let's say it's the right one — which created the illusion that the left hand was still there. When Ramachandran tried mirror therapy with his patients, the results were so immediate as to be shocking. Patients who had suffered abominable agony for years suddenly "saw" their amputated limb and could move it naturally. The brain convinced itself that neurons were once again firing in the missing limb, so it finally dialed down its pain signals. Since then, other teams — including one from the Walter Reed Army Medical Center — have replicated Ramachandran's case studies in (rather small) placebo-controlled clinical studies.
Not long ago, I visited New York University's Rusk Institute of Rehabilitation Medicine, where I met Mark Constantino, 65, who lost his right leg below the knee to Type 2 diabetes last year. His doctor, Jeffrey Cohen, who directs the limb-loss program at Rusk, used mirror therapy to help Constantino get back to normal functioning. For 15 minutes each day, five days a week for four weeks, Constantino would watch his left foot move — and, in the mirror, "see" his right foot also moving.
Constantino told me that the mirror-therapy sessions helped reduce the pain in his phantom limb from a fairly bad 7 (on a scale of 1 to 10) to an annoying but tolerable 2 to 3. The remarkable part: the benefit from four weeks of mirror therapy has lasted for months. Except for demonstrating the therapy for me, Constantino hasn't used it since last fall.
Goodman, the alligator victim, sometimes uses mirror therapy by himself at home, but his doctor — Robert Hurley, director of the University of Florida's pain medicine program — doesn't employ mirror therapy in his practice. Hurley told me the therapy doesn't have a strong enough basis in evidence quite yet.
And that's where many CAM therapies stand: they show only promising anecdotal results. But research scientists and everyday pain specialists recognize that a combination of traditional therapies like acupuncture must work in concert with new drugs and psychotherapies in order to advance the fight against pain.