Only a few studies on the effectiveness of mirror therapy exist, but initial conclusions show the technique very promising for phantom limb pain and recovery after stroke. Neurologists cannot explain how mirror therapy works, but believe it tricks the brain by giving the illusion of two working limbs. Mirror therapy is considered an inexpensive and effective way to reduce the amount of pain suffered by amputees.
A 2007 study of mirror therapy at Walter Reed Army Medical Center in Washington, D.C., included 18 war veterans who lost limbs in conflict. Long mirrors were placed alongside the remaining limbs in one group of study participants. Patients were asked to move the limb while watching their actions in the mirror. A second group studied used covered mirrors, while a third group used visualization to imagine missing limbs.
In the first group, all patients said they felt less phantom pain. In some cases, the decrease in sensation was so significant the patients were able to give up pain medication. One person in the second group reported less pain, but more than half of participants felt an increase. Two-thirds of the third group got worse. When veterans in the two control groups switched to mirror therapy, 90 percent reported less pain.
These results came after four weeks of using mirror therapy for 15 minutes a day, five days a week. Dr. Jack Tsao, a U.S. Navy neurologist, conducted the study after recalling a research paper he read while in graduate school written by Dr. V.S. Ramachandran, a U.S. scientist specializing in neurology. Ramachandran contended the mirror tricks the brain into responding to two limbs, which is reinforced by mirror images of movement.
Phantom limb pain represents a function of the brain that signals nerve endings that remain near an amputated part of the body. Neurons might fire to spark movement after the limb has been surgically removed. The brain also experiences sensations that the limb remains, called proprioception. When these signals get crossed, it might cause phantom pain. Some amputees describe the discomfort as a mild tingling, while others report sensations of burning or shocking pain.
Mirror therapy might also help stroke victims suffering from hemiplegia, defined as paralysis of the arms, legs, and torso on one side of the body. A study of 14 patients used mirrored boxes fitted with a small step to practice flexing their ankles. Most of these patients were able to step up more quickly when watching the movements in the mirror. Doctors believe cognitive therapy using mirrors might be as important as physical therapy in stroke recovery.
