But coupling the technique known as cortical stimulation with aggressive rehabilitation is key to reversing the impairment, doctors say.

In a study examining the safety of cortical stimulation therapy, Helmi Lutsep, M.D., associate professor of neurology and associate director of the Oregon Stroke Center, Oregon Health & Science University School of Medicine and co-investigators found that stroke patients who received stimulation with rehabilitation improved "significantly" better in hand mobility and strength tests than people undergoing rehabilitation alone.

"Everybody improved to some degree, because even in the subjects who received some rehabilitation, we did see improvement," Lutsep said. "What the data suggested is those who received the stimulation implant improved more."

In cortical stimulation, an external pulse generator sends a low current through a wire to an electrode placed surgically atop the dura. The electrode rests above the motor cortex. Surgeons pinpoint the site using "neuronavigation" techniques, including functional magnetic resonance imaging, or fMRI, then remove a circular, 4-centimeter flap of the skull to access the dura.

Eight individuals ages 33 to 74 completed the Neurosurgery study. Each had suffered motor deficits resulting from a stroke that occurred at least four months before, and was randomly placed into one of two groups: An active treatment group that received cortical stimulation with three weeks of rehabilitation, and a control group that received rehabilitation alone. In the active treatment group, the device was turned on only during rehabilitation sessions.

The study found that patients in the active treatment group "improved to a significantly greater degree" than control patients, and they continued to improve through the three-week treatment period and into a fourth week, when a follow-up assessment takes place.

MEDICA.de; Source: Oregon Health & Science University