The study was small but is the best evidence yet that this simple and novel treatment may help restore movement to hundreds of thousands of stroke victims left with impaired limbs.
"Even if you are a long time after your stroke, there is a hope of gaining recovery," said study co-author Gitendra Uswatte, assistant professor of psychology at University of Alabama at Birmingham.
Patients also retained the benefits of this brief treatment up to two years afterward, according to the findings published Thursday in the American Heart Association's online journal Stroke.
It is the second study in two weeks to report success with constraint or "forced use" therapy, in which a hand splint or sling is used to immobilize the patient's good arm while intensive daily physical therapy is given to strengthen the weak one.
The idea is to try to encourage the brain to rewire itself and send more signals to the impaired area and help it recover.
Traditionally, doctors thought maximum recovery was reached within six months to a year after a stroke. However, the new study suggests hope beyond that point.
Researchers put 21 people with mild to moderate impairment in their arms about five years after surviving a stroke through constraint therapy for 10 days. A comparison group of 20 similar stroke survivors got a general exercise program instead.
That group didn't significantly improve. However, the group forced to use the weak arm improved at daily activities like holding a book, using a towel, picking up a glass or brushing their teeth.
In some of the most dramatic cases, patients began using their affected arm to write again. Some patients would come to therapy with a hand or arm hanging limply and by the end of the therapy be spontaneously gesturing, Uswatte said.
"This wasn't months and months of treatment, this was 10 days of treatment," said Dr. Milton Thomas of the Baylor Institute for Rehabilitation in Dallas, who had no role in the study.
The study's lead author, Edward Taub, a psychology professor at the University of Alabama at Birmingham who pioneered constraint therapy, said there is a "use it or lose it" phenomenon after a stroke — if a patient avoids using an impaired limb, it will gradually get even weaker.
"The important thing is to get the person doing it, once they do it they get better," Taub said.
Doctors caution that such therapy should be done with a physical therapist. And stroke patients shouldn't think the approach will help them "get back to normal," said Dr. Jeffrey Teraoka, medical director of the rehabilitation unit at Stanford University Medical Center.
"Some patients get a fair amount of improvement and some get a little movement in their hand," said Teraoka, who was not part of the study. "That's a far cry from being back to normal."
Even so, he said, "I think constraint-induced therapy does work — this validates the theory behind it all."
By Jamie Stengle