Small Study Indicates Stroke Rehabilitation Possible
Six Months After Stroke
Robotic technology with aid of functional MRI
improves stroke rehabilitation
Dec. 3, 2008 Although the study was very small
the results could point to something big the rehabilitation of stroke
victims even months after the stroke. Scientists using a novel,
hand-operated robotic device and functional MRI (fMRI) have found that
chronic stroke patients can be rehabilitated, according to a study
presented today at the annual meeting of the Radiological Society of
North America (RSNA).
This is the first study using fMRI to map the brain
in order to track stroke rehabilitation.
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"We have shown that the brain has the ability to
regain function through rehabilitative exercises following a stroke,"
said A. Aria Tzika, Ph.D., 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 U.S. and a
principal cause of severe long-term disability. Approximately 700,000
strokes occur annually in the U.S., and 80 percent to 90 percent of
stroke survivors have motor weakness.
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 said.
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. Tzika said.
Background Information
Co-authors are Dionyssios Mintzopoulos, Ph.D.,
Azadeh Khanicheh, Ph.D., Bruce Rosen, M.D., Ph.D., Loukas Astrakas,
Ph.D., and Michael Moskowitz, M.D.
RSNA is an association of more than 42,000
radiologists, radiation oncologists, medical physicists and related
scientists committed to excellence in patient care through education and
research. The Society is based in Oak Brook, Ill. (RSNA.org)
Magnetic resonance imaging (MRI) is a noninvasive
medical test that helps physicians diagnose and treat medical
conditions.
MR imaging uses a powerful magnetic field, radio
frequency pulses and a computer to produce detailed pictures of organs,
soft tissues, bone and virtually all other internal body structures. The
images can then be examined on a computer monitor, printed or copied to
CD. MRI does not use ionizing radiation (x-rays).
Detailed MR images allow physicians to better
evaluate parts of the body and certain diseases that may not be assessed
adequately with other imaging methods such as x-ray,
ultrasound or
computed tomography (also called CT or CAT scanning).
Functional magnetic resonance imaging (fMRI) is a
relatively new procedure that uses MR imaging to measure the tiny
metabolic changes that take place in an active part of the brain.
What are some common uses of the procedure?
fMRI is becoming the diagnostic method of choice
for learning how a normal, diseased or injured brain is working, as well
as for assessing the potential risks of surgery or other
invasive treatments of the brain.
Physicians perform fMRI to:
● examine the anatomy of the brain.
● determine precisely which part of the brain is
handling critical functions such as thought, speech, movement and
sensation, which is called
brain mapping.
● help assess the effects of stroke, trauma or
degenerative disease (such as Alzheimer's) on brain function.
● monitor the growth and function of brain
tumors.
● guide the planning of surgery,
radiation therapy, or other surgical treatments for the brain.
Dec. 3, 2008 Although the study was very small
the results could point to something big the rehabilitation of stroke
victims even months after the stroke. Scientists using a novel,
hand-operated robotic device and functional MRI (fMRI) have found that
chronic stroke patients can be rehabilitated, according to a study
presented today at the annual meeting of the Radiological Society of
North America (RSNA).