Putting Arm to Sleep Helps Hand Recover Post-Stroke
Thu Aug 15, 2:49 PM ET
By Merritt McKinney

NEW YORK (Reuters Health) - An experimental therapy that involves temporarily anesthetizing the upper arm may help restore hand function after a stroke, according to a new study.

The technique is not yet ready for widespread use, but it could be one of the first therapies to help the many stroke patients who never completely regain normal hand function, according to the study's lead author, Dr. Mark Hallett of the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland.

"Hand weakness in chronic stroke patients may still be able to be improved with novel methods," Hallett told Reuters Health. "Such patients have ordinarily been assumed to be permanently damaged, but this gives hope that at least some improvement beyond spontaneous recovery can be achieved."

When a stroke impairs the normal function of the hands, recovery is possible, but it usually plateaus about a year after the stroke. In most cases, patients have better control of their upper arms than their hands.

In recent years, scientists have been exploring the possibility that the various body parts compete for space in the brain. If this is the case, the turf war in the brain may mean that the improvement in function of the upper arm comes at the expense of the hands.

Based on the discovery that interrupting the brain activity involved with one body part increases the activity of nearby body parts, Hallett's team studied how the hand responds when the upper arm is put to sleep temporarily. The experiments included seven patients who had weak hand function after a stroke. Results of the study are published in the August issue of the journal Archives of Neurology.

In a first round of tests, patients practiced hand exercises without receiving anesthesia. Hand function, such as the ability to pinch, improved, but the patients reached a plateau after which they did not improve any further.

When the upper arm was anesthetized, however, participants were able to improve their hand function even more, according to the report.

In his comments to Reuters Health, Hallett pointed out that the human brain is always capable of reorganizing itself "and this method takes advantage of that capacity."

But even if future studies confirm the safety and effectiveness of the approach, it may be altered somewhat before it can be widely used, since it is "somewhat invasive" and would probably be expensive, according to Hallett.

"However, it may be one of the first methods to point the way that this improvement is possible and that easier methods might be developed to take its place," he said.

SOURCE: Archives of Neurology 2002;59:1278-1282.