Stroke theory: Use the bad arm
Forcing stroke patients to use an impaired arm by immobilizing their good one for two weeks produces significant long-term improvements in the arm’s function, boosting mobility and quality of life, researchers reported today.
The therapy is the exact opposite of conventional treatments, which emphasize using the unimpaired arm.
“This study is likely to have a significant impact on clinical care for stroke survivors,” said Dr. Elias A. Zerhouni, director of the National Institutes of Health.
The government-sponsored study, published in the Journal of the American Medical Assn., also breaks new ground because it is one of the “very, very few controlled trials” that have been conducted in stroke rehabilitation, said Dr. Richard Zorowitz of the Johns Hopkins Bayview Medical Center in Baltimore, who is the rehabilitation and recovery chairman of the National Stroke Assn.
Current rehabilitation techniques are based on guesswork and experience, not scientific evidence, he said. “We were really anticipating this, and we are very happy,” he said.
About 730,000 Americans have strokes each year, and as many as 85% of them have some paralysis on one side of the body.
The technique, constraint-induced movement therapy, has been shown to be effective for many patients in small, uncontrolled trials, but it had never been directly compared with conventional therapy.
The new trial, sponsored by two institutes at NIH, enrolled 222 stroke patients at seven U.S. hospitals. All had suffered an ischemic stroke -- caused by a blood clot in the brain -- three to nine months before enrollment.
Half received conventional treatment and half received a two-week course of treatment in which the less-impaired arm and hand were immobilized in a boxing-glove-like mitt and a sling during waking hours. Every weekday, the patients received 6 1/2 hours of repetitive motion therapy on the weaker arm.
At the end of the two weeks, those receiving the therapy showed an average 52% reduction in the time required to complete certain tasks with the impaired arm, compared with a 26% reduction among those receiving conventional therapy.
They also experienced a 24% increase in the proportion of daily tasks accomplished using the impaired arm and a 65% increase in the quality of the movement, said Steven L. Wolf, a professor of rehabilitative medicine at Emory University School of Medicine, who led the study.
The improvements were maintained at least a year after the therapy, the full time the patients were monitored.
Studies in animals and previous imaging studies in humans suggest that the technique recruits unused areas of the brain to take the place of those areas damaged by the stroke, a concept called neurorehabilitation.
“This study demonstrates that aggressive neurorehabilitation can lead to a better functional outcome,” said Dr. Nerses Sanossian, a USC neurologist who is a spokesperson for the American Heart Assn. “It is important that people who are stroke survivors are treated at centers with this expertise.”
The therapy is not for all stroke victims, however. Patients must have a minimum ability to extend the wrist and fingers, a group that includes about 30% of stroke victims.
But for those who are eligible, the report “clearly suggests that more recovery after stroke is possible than neuroscientists currently teach ... and than clinicians have been telling patients to expect,” according to an editorial in the same journal by Dr. Andreas R. Luft of the University of Tuebingen in Germany and Dr. Daniel F. Hanley of the University of Maryland School of Medicine and Johns Hopkins University.
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