Targeted training of the better arm improved movement and daily function in chronic stroke survivors, a phase II randomised trial has found.
After a stroke, damage in the brain can slow and unbalance both arms.
The less-impaired arm often looks normal but loses speed and coordination needed for everyday tasks.
A total of 53 chronic stroke survivors were randomly assigned to either targeted training for the less-impaired arm or standard therapy for the more impaired arm, three times a week for five weeks.
Those receiving targeted therapy practised real-world dexterity tasks and virtual-reality games tailored to stroke side: planned fast reaching after left-hemisphere injury, and continuous precision tracing after right-hemisphere injury.
Controls received best-practice therapy for the more impaired arm, including stretching, therapeutic exercise and task-specific practice.
Candice Maenza is project manager for the neurorehabilitation research laboratory at Penn State College of Medicine and first author.
The researcher said: “At the end of the trial, when we train the less-impaired arm, the individuals got better.
“This could improve quality of life and reduce the burden of care for caregivers because stroke survivors with severe paralysis on one side rely on this arm for daily tasks like eating or dressing.”
Participants in the targeted-training group improved more than controls on a standard dexterity test, completing tasks such as picking up small objects, flipping cards and simulated feeding 12 per cent faster, nearly six seconds quicker than baseline.
Robert Sainburg is study co-author and distinguished chair in kinesiology and neurology at Penn State.
He said: “You’re already doing things mostly with one hand and that’s really hard in itself.
“Now, the effect of the stroke on the less-impaired arm has added an additional deficit on top of that, say a 10 to 25 per cent loss of motor coordination in the hand that has the most function.”
Gains persisted for at least six months, suggesting a virtuous cycle in which small improvements encourage more independent use.
Carolee Winstein is professor emerita and adjunct faculty in biokinesiology and physical therapy at USC and co-principal investigator.
Winstein said: “This is the first project to use a rigorous randomized clinical trial design to investigate the use of ipsilesional limb training, training the less-impaired arm, in chronic stroke survivors with severe paresis.”
The team plans to test combinations of ipsilesional training with bilateral approaches so each arm is trained according to the different control roles of the brain’s hemispheres.
