Electrical Stimulation Procedure May Aid Stroke Recovery

Originally Published MDDI December 2003

R&D DIGEST

Maureen Kingsley

A new surgical procedure involving electrical stimulation may help restore the use of hands and arms to some stroke victims. The procedure involves affixing a tiny electrode onto the brain's protective membrane layer. The electrode, powered by a battery pack and placed into position using an MRI scan, delivers electrical stimulation to parts of the brain responsible for hand or arm function and movement.

The study, sponsored by Northstar Neuroscience Inc. (Seattle), is taking place at Northwestern Memorial Hospital (NMH; Chicago) and four other sites. It will determine whether stroke survivors suffering impaired extremity movement can make greater progress in their recovery when traditional physical rehabilitation is coupled with electrical stimulation of the motor cortex. 

Alan Levy, Northstar's CEO, explains that the procedure used to implant the electrode is designed to be relatively simple and straightforward. The electrode itself is “very flat and thin; I would say postage-stamp sized,” he says. “It sits on the dura mater, the brain's tough covering. It's designed to be very flexible and to go in through as small an opening as possible.”

Robert Levy, MD, PhD, is leading the NMH portion of the study. Levy is professor of neurosurgery and physiology at the Feinberg School of Medicine at Northwestern University. He describes the technology as being “based on devices that physicians have been using for decades—electrodes over the brain and battery packs to drive the electrodes.” Such methods have been in use since the 1960s, he says. 

But the devices being studied in the NMH trial are modified, and the technology to place them correctly in patients with strokes represents advancements in neuroimaging techniques. “For example,” he says, “the study we're doing looks at arms that have been rendered weak by stroke. We have a paradigm whereby patients are told to move their arm and to think about moving their arm while in the MRI scanner, and that area of the brain lights up on the scan. And that's the spot—precisely—where we put the electrode.”

Alan Levy says Northstar plans to do another, larger study of the device within the next year and, assuming all goes well in both studies, apply for FDA approval soon afterward.

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