A new study shows people who had lost significant strength in arm movement due to a stroke were able to achieve modest gains in limb movement and function as well as an improved outlook on life after undergoing intensive therapy an average of five years after their stroke.
Researchers say the results provide the best evidence yet that stroke survivors can regain some lost movement long after their stroke. In the U.S., stroke survivors typically receive stroke rehabilitation therapy only during the first six months after a stroke because the conventional wisdom is that lost movement cannot be regained after that point.
"There are about 6.4 million stroke patients in the U.S. with chronic deficits. We've shown that with the right therapy, they can see improvements in movement, everyday function, and quality of life," says researcher Albert Lo, assistant professor of neurology at Brown University, in a news release. "One of the purposes of this study was to upend the conventional dogma that stroke victims can't recover physiological function."
Using Robots to Regain Arm Movement
The study, published in The New England Journal of Medicine, involved 127 veterans who had suffered a stroke at least six months earlier that caused moderate to severe impairment of an arm. On average, the stroke had occurred nearly five years before enrollment in the study.
The participants were divided into three groups: one group received intensive stroke rehabilitation therapy with the use of robotic aids, another did similar exercises with a therapist, and the third group received only general health care and no stroke rehabilitation therapy.
For the first two groups, stroke rehabilitation therapy consisted of 36 one-hour sessions over a period of 12 weeks, during which they performed 1,024 upper-arm movements either with a robotic aid or with a therapist.
In the robot-assisted group, the participants sat at a table with their affected arm attached to the device and followed therapists' instructions or computerized prompts to move a cursor on a screen, like playing a video game. The robotic aid sensed their movements and provided help as needed.
Immediately after the therapy ended, researchers found people who received robot-assisted therapy showed significant improvement in their quality of life (an 8-point improvement on the Stroke Impact Scale) compared to those who received no therapy. No other significant differences were found at 12 weeks between the three groups.
But six months after the study began, the results showed that those who had received either type of intensive stroke rehabilitation therapy had improvements in upper-arm function (an average of a 3-point improvement on a stroke recovery scale).
Both intensive stroke rehabilitation therapy groups also reported improved progress in activities of their everyday life, such as cutting food with a fork and knife, opening jars, and tying shoes.
"We believe that by gaining more function and better control of their affected arms, patients were able to get out and do more, translating their motor benefits into additional meaningful social activity and participation," says Lo.
Researchers say long-term intensive stroke rehabilitation therapy, with or without robots, takes advantage of the brain's neuroplasticity -- the ability of the brain to "rewire" itself and compensate for lost function after damage.