fMRI shows robotic hand exerciser improves brain function of stroke
10 December 2008
Chronic stroke patients can be rehabilitated by a hand-operated
robotic device, according to a study that used functional MRI (fMRI)
scans to map changes in the brain. The study, presented at the annual
meeting of the Radiological Society of North America (RSNA), is the
first to use fMRI to map the brain in order to track stroke
A volunteer squeezing the handles of the Magnetic
Compatible Hand-Induced Robotic Device (MR_CHIROD) while
lying in the magnet of the MRI scanner.
"We have shown that the brain has the ability to regain function
through rehabilitative exercises following a stroke," said Dr Aria Tzika,
director of the NMR Surgical Laboratory at Massachusetts General
Hospital (MGH) and Shriners Burn Institute and assistant professor in
the Department of Surgery at Harvard Medical School in Boston. "We have
learned that the brain is malleable, even six months or more after a
stroke, which is a longer period of time than previously thought."
According to the Centers for Disease Control and Prevention, stroke
is the third leading cause of death in the US and a principal cause of
severe long-term disability. Approximately 700,000 strokes occur
annually in the US, and 80% to 90% of stroke survivors have motor
Previously, it was believed that there was only a short window of
three to six months following a stroke when rehabilitation could make an
improvement. "Our research is important because 65 percent of people who
have a stroke affecting hand use are still unable to incorporate the
affected hand into their daily activities after six months," Dr Tzika
Dr. Tzika is an affiliated member of the Athinoula A. Martinos Center
for Biomedical Imaging in the Department of Radiology at MGH, where the
research is ongoing.
To determine if stroke rehabilitation after six months was possible,
the researchers studied five right-hand dominant patients who had
strokes at least six months prior that affected the left side of the
brain and, consequently, use of the right hand.
For the study, the patients squeezed a special MR-compatible robotic
device for an hour a day, three days per week for four weeks. fMRI exams
were performed before, during, upon completion of training and after a
non-training period to assess permanence of rehabilitation. fMRI
measures the tiny changes in blood oxygenation level that occur when a
part of the brain is active.
The results showed that rehabilitation using hand training
significantly increased activation in the cortex, which is the area in
the brain that corresponds with hand use. Furthermore, the increased
cortical activation persisted in the stroke patients who had exercised
during the training period but then stopped for several months.
"These findings should give hope to people who have had strokes,
their families and the rehabilitative specialists who treat them," Dr.
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