Stroke Survivors Can Regain Use Of Partially Paralyzed Arm
Posted by medconsumers on December 1, 2004
Stroke survivors who have lost partial use of an arm can be helped with intensive retraining exercises. All they need is a great deal of patience. Evidence has been slowly mounting to contradict the longstanding belief that only minor improvements can be achieved one year after a stroke. The latest study involved people whose arms were moderately to severely affected and who were about four years post-stroke.
Limb paralysis afflicts most people who suffer a stroke, though some spontaneously recover use of the arm within the first three to six months. Unfortunately, many remain impaired despite standard rehabilitation care that typically lasts around six weeks. Some rehabilitation centers, however, have been pushing the frontiers with variations of a retraining technique that involves hours of repetitive exercises.
A technique called constraint-induced movement therapy has received media attention over the last few years. The unaffected arm is restrained with a sling or a splint while the stroke survivor forces repetitive use of the partially paralyzed arm. Another approach, which is called bilateral arm training with rhythmic auditory cueing, or BATRAC, was the subject of the newly published study. For this therapy both arms are forced to do repetitive push and pull movements using “auditory cueing” that provides a rhythmic beat. Researchers hope that activating both sides of the brain may result in the unaffected side “helping” the affected side of the brain. Unlike constraint-induced therapy, neither arm is constrained.
This study involved 21 participants; all were about four years after having had a stroke that affected one arm. They had been randomly assigned to BATRAC or to a simple standardized exercise program. Both types of exercises were performed for one hour, three times a week for six weeks. Most of the study took place at a VA medical center.
Earlier research had already shown that BATRAC improves arm function. The purpose of the new study, however, was not to see which technique is superior. Instead the objective was to see whether improvements in arm function in the BATRAC group were associated with “brain reorganization.” This was clarified in a telephone interview by the study’s principal investigator, Jill Whitall, PhD, Department of Physical Therapy and Rehabilitation Science, University of Maryland School of Medicine.
“Brain reorganization means that after the study, the brain was activated in a new place for the same movement,” she said. This was determined by having the study participants undergo what is called “functional MRIs.” Normally, people are told to hold still during magnetic resonance imaging (MRI), but the people who underwent functional MRIs in this study were instructed to move their arms while they were under the scanner.
“We found that certain areas of the brain lit up before training and then certain new areas lit up after training,” said Dr. Whitall, “Only in those with brain activation did we see improvements in motor function as well—that was six patients out of the nine in the BATRAC group. Three [of the BATRAC participants] did not show improvements in motor function or brain activation,” she continued. “Another interesting result: the area of the brain that lit up after BATRAC was the opposite side of the brain and that means the other side of brain, that typically just controls the unaffected arm, was brought into play.”
Do It Yourself
That’s interesting for the researchers, but where does that leave the stroke survivor who wants to choose a rehab approach that’s most likely to succeed. “It may not matter what type of therapy you use,” said Dr. Whitall, who noted that in her study participants improved in each group. “The bottom line is there is still hope for stroke survivors, whether they use the unilateral constraint therapy or the bilateral approach that means exercising both arms at the same time,” she continued, “It is the amount of time people are willing to devote to repetitive training that is probably the most important.” Some proponents advise restraining the unaffected arm for 90% of waking hours and using only the affected arm.
Dr. Whitall did make one distinction that would help stroke survivors decide upon a therapy. She said that the studies showing a benefit to constraint-induced therapy involved people with mild arm paralysis; whereas, the two studies she has co-authored indicate that BATRAC might be better for people with a moderately to severely affected arm. “We were testing patients who were more low-functioning, though no one was completely unable to move the arm, wrist, hand or fingers,” she said, explaining that stroke survivors must be capable of at least some movement in order to benefit from therapy.
Large Trial in Progress
The new study should be considered preliminary because it included only 21 people who were followed for only two months. It was funded by National Institutes of Health and National Institute on Aging. A large ongoing clinical trial is currently in progress.
At the end of the phone interview, Dr. Whitall was asked how a stroke survivor could find a rehabilitation center that teaches repetitive exercises. “It’s easy to do the constraint-induced therapy yourself,” she said, referring to the approach that involves restraining the “good” arm with a sling or splint.
“In fact, it may not be necessary to actually restrict the use of the unaffected arm as long as the affected arm is used as often as possible during tasks,” Dr. Whitall advised. “Just use the affected arm in a repetitive and active way. Doing tasks that use both arms, without the unaffected helping the affected arm, should also have benefits; and using a beat to help keep the exercise going may also be useful.”
Maryann Napoli Center for Medical Consumers ©