WEDNESDAY, May 25, 2005 (HealthDay News) -- Sending magnetic pulses through the brain might improve the physical performance of people who suffer strokes, according to results of a small study.
There was a noticeable improvement in hand function for the eight people who had suffered a stroke in the past year and who received the magnetic impulses, said researchers at Beth Israel Deaconess Medical Center in Boston.
The findings appear in the May 24 issue of Neurology.
No improvement was noted when the stroke patients got sham treatment. And no change in performance was found in six people who had never had a stroke but got the magnetic treatment, the researchers said.
"These results are exciting because magnetic stimulation is a noninvasive, painless therapy that can be done while patients are awake," said Dr. Filipe Fregni, an instructor in neurology at Harvard Medical School and a staff neurologist at Beth Israel Deaconess.
Contrary to what might be expected, the magnetic pulses were sent through the hemisphere of the brain that was not damaged by stroke. The idea was to stimulate activity in the damaged hemisphere by slowing the activity of the undamaged cortex, Fregni said.
"There is some connection between the two motor cortexes," Fregni said. "We thought that changing the conditions of the unaffected hemisphere might improve the activity of the affected hemisphere."
Activity improved by as much as 50 percent on some tests, such as reaction time to a stimulus and how many finger taps could be performed in a given period, the researchers reported.
However, this was a small study that needs confirmation through larger trials with more patients, Fregni said. His group has already done one such trial, using a slightly different technique, that has produced promising results, he said.
The newly reported trial used a method called repetitive transcranial magnetic stimulation, in which an insulated wire coil is placed on the scalp and a brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the cortex. The later study used a technique called transcranial direct current stimulation, which "is a little less invasive and uses less current," Fregni said.
Dr. Tobias Kurth is a neuroepidemiologist at Brigham and Women's Hospital in Boston, and a spokesman for the American Academy of Neurology. He said the study is "important because it may provide some hope of improving motor function," but added that it should not arouse undue expectations.
"This was a small improvement," Kurth said. "However, even small improvements are important to stroke patients. You may not be able to use your hand as before the stroke, but a small improvement in hand function may make a huge difference."
Kurth agreed that other studies are needed to confirm the value of brain stimulation in stroke rehabilitation.
More information
You can learn about stroke by visiting the National Institute of Neurological Disorders and Stroke.
