News - Hypertension Week of June 8, 2003/ Vol. 2 No. 23

Study: Stroke Victims May Retain More Motor Skills Than Thought

New study findings showing that stroke victims retain some motor skills thought to be lost could open up new ways to help them deal with everyday tasks.

As reported in the May 30 issue of Science, Purdue University and University of California researchers found that the cerebellum may not be as responsible for continuous motions as it is for start-stop motions.

The cerebellum is the part of the brain that governs motor skills from walking to blinking to catching a ball. Strokes can leave damaging lesions on the cerebellum that make it difficult for victims to control their muscles, especially when it comes to activities that require a sense of timing.

Specifically, the researchers found that patients with cerebellum damage had difficulty with the start-stop motion of tapping a steady beat with their fingers, but not much trouble with drawing circles in rhythm.

"If the same part of your brain governs timing of all your muscular activity, you should have equally good rhythm when tapping your finger as when you draw circles," said study co-author Howard Zelaznik, a professor of kinesiology at Purdue. "But we found that one skill doesn't predict the other. So if part of your brain gets traumatized through injury, you may not necessarily lose all your motor skills."

What the researchers do not know is how muscles allow for circular motion to be carried out if the cerebellum is not telling them. Zelaznik said additional research is needed with a larger group of participants to answer that question.

Zelaznik said the findings could be used in determining how to design devices to help brain-damaged patients with everyday tasks.

"Many such devices make use of point-and-click technology, such as many of us use at our computers," Zelaznik. But pointing and clicking are just the sort of interrupted, discontinuous motions that a damaged cerebellum appears to have trouble with."

A more viable alternative would be continuous-motion based controllers, added Zelaznik. "For individuals with certain kinds of cerebellum damage, we might want to create electric wheelchairs they can steer by varying the speed at which they turn a small crank, for example," he observed.

Other sources: Purdue University