Groundbreaking new study that may help stroke patients regain greater use of their hands or arms

Oct 21 2004

Researchers are conducting a groundbreaking new study that may help stroke patients regain greater use of their hands or arms through treatment with electrical stimulation.

Preliminary results of the feasibility study that precedes this new study have shown that the use of electrical stimulation, called motor cortex stimulation, may be both safe and effective, according to Robert Levy, M.D., Ph.D., a neurosurgeon at Northwestern Memorial Hospital in Chicago. Dr. Levy presented this feasibility trial data at the Congress of Neurological Surgeons Wednesday in San Francisco.

The trial showed that study participants – stroke survivors suffering impaired hand or arm movement – who underwent physical rehabilitation accompanied by motor cortex stimulation showed greater improvement than participants who received physical rehabilitation alone. Twenty-four subjects participated in the feasibility study, 12 in the electrical stimulation group and 12 in the control group. "Participants in the electrical stimulation group experienced meaningful motor recovery gains," Dr. Levy says.

The study, sponsored by Northstar Neuroscience, Inc., is close to completing the follow-up period. Ongoing and further research is needed to validate these findings. Other sites in the study were the University of Illinois-Chicago, Rush University Medical Center, University of Arizona, Wayne State University, University of Minnesota and Kansas University.

"It is our hope that by stimulating the surface of the brain we can permanently reverse paralysis and rekindle patients' function, returning them to their normal lifestyle," says Dr. Levy, who is a professor at the Feinberg School of Medicine at Northwestern University and who is leading the study at Northwestern Memorial, which is being conducted in tandem with the Rehabilitation Institute of Chicago. "Unfortunately, when patients have had a stroke, there is not much we can currently offer beyond physical rehabilitation to improve their motor functions."

Researchers are testing the new surgical procedure, involving the implantation of tiny investigational electrodes on the surface of the brain, in hopes of "jump starting" the growth of new nerve fibers, or retraining a new area of the brain to take over functions impaired by stroke damage.

In the study, surgeons place a set of small stimulating electrodes on the protective membrane over the outer surface, or cortex, of the brain corresponding to areas of the brain where motor skills were affected by stroke. The electrode connects to a wire running under the skin to below the collarbone, which is then hooked up to an implanted pulse generator. The device is turned on only during a participant's physical therapy sessions.

Doctors hypothesize that the electrical charges help in one of two ways – either by stimulating the growth of new nerve fibers in the area of the brain affected by stroke, or by helping enable other areas of the brain to take over lost functions.

The other portion of the study in Chicago is being led by Dr. Mark Huang and Mary Ellen Phillips, occupational therapist, at the Rehabilitation Institute of Chicago (RIC). At RIC, the study participants are randomly divided into two groups: one that participates in very aggressive six-week occupational therapy protocol alone; or one that participates in the same aggressive occupational therapy accompanied by motor cortex stimulation. At the end of the trial the functional improvement of each group is measured to determine whether the cortical stimulation had the desired effect.

The current trial, also sponsored by Northstar Neuroscience, is open to participants who are at least 21 years of age and experiencing significant weakening of the hand and/or arm, but with some ability to move or twitch, that persists for at least four months following a stroke. Stroke survivors who may be interested in participating in the trial and family and friends interested in more information can contact 888-546-9779. Participants undergo magnetic resonance imaging (MRI) to identify the area of the brain where arm function is affected. Participants randomized to receive the investigational device then have an electrode placed on the protective membrane over the area of the brain identified by the MRI as affected by stroke. The electrode connects to a pulse generator implanted below the collarbone. At the end of six weeks of intensive occupational therapy and completion of required follow-up periods, the device is removed. Doctors hope to see significantly more recovery in the participant group receiving stimulation.

Stroke is the third leading cause of death and the most common cause of disability in the United States. Of the 700,000 strokes each year in the U.S, between 150,000 to 250,000 result in severe and permanent disability. "If cortical stimulation proves safe and effective, the reduction in motor impairment for stroke victims would have a huge impact on health, economics and quality of life for thousands of people," says Dr. Levy.