A robotic arm and a virtual game were essential tools in a new study from researchers at Johns Hopkins Medicine. The study results suggest that while training doesn't change neurological repair in chronic stroke patients, it can indeed help such patients learn new motor skills and achieve more independence in their daily lives.

A report on the work is published in the journal Neurorehabilitation and Neural Repair on Oct. 27.

"What we found is that physical rehab is not going to change the weakness caused by damaged brain cells in chronic patients, but it is going to change how well they can perform certain tasks, which can have a huge impact on a patient's daily life," says Pablo Celnik, M.D., director of the Department of Physical Medicine and Rehabilitation at Johns Hopkins.
Brain damage from strokes occurs when the blood supply to the brain is blocked (ischemic stroke) or a blood vessel feeding brain tissue ruptures (hemorrhagic stroke). Depending on the extent of the stroke, the damage can cause partial or total paralysis, affecting motor function, balance, speech, sensation and other physical activities. Chronic stroke patients are those whose physical impairments persist more than six months after the stroke. Rehabilitation specialists measure the damage using the Fugl-Meyer Assessment (FMA), which measures the neurological damage wrought by a stroke on a scale from zero to 66.

For the new study, the investigators recruited 10 chronic stroke patients with FMA scores of ?50 out of 66 and categorized them as having "mild to moderate" functional deficits for the purposes of the study, and 10 other patients with FMA scores of <50 out of 66 and categorized them as having "moderate to severe" impairment. A third group of 10 able-bodied participants served as a control group.

All of the study participants were trained to control a simple video game using a using a robotic piece of equipment that held their dominant arm at 90 degrees from their bodies. This eliminated gravity as a burden for those whose arms were weakened by their strokes. The subjects were then taught to use the muscles around their elbow to move a cursor across a screen into small target windows.

Participants' performance in the game was measured during training sessions and skill assessment trials. A pre-training skill assessment was conducted to get a baseline from which to measure improvement. Participants were asked to move the cursor through the windows in time with a metronome and completed nine blocks of 10 trials at various speeds -- 24, 30, 38, 45, 60, 80, 100, 110 and 120 beats per minute. The metronome prevented participants from slowing down to improve their accuracy, so the only way to show improvement was by becoming more skilled at the task.

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