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Ties
That Bind Help Stroke Patients Fred
Kemp, 38, a former restaurant manager in Atlanta, Ga., has one
simple goal: To open a refrigerator door with his left hand. Five
years ago, Kemp suffered a stroke as he dozed in front of his TV.
When he woke up, he recalled, "I couldn't get up. I tried
again and again. I couldn't move my left side," forcing the
former military hospital corpsman to dial 911 for an ambulance
with his good right hand. Ever
since - until very recently - doctors gave him little hope that he
would regain use of his left arm. Every
year, 600,000 Americans like Kemp have a stroke, a kind of heart
attack in the brain caused by a blood clot or hemorrhage. Many
stroke victims die, and many others don't get effective treatment
because they don't get to the hospital soon enough. Indeed, stroke
is still the third leading cause of death in America, after heart
disease and cancer. But,
increasingly, people are surviving strokes. While that's good
news, it also means that there are more than 4.4 million stroke
survivors living with varying degrees of disability. Now,
preliminary research shows that rehabilitation of long-paralyzed
arms and legs may be far more possible than doctors once believed,
at least for some types of stroke survivors. At the mecca for
stroke rehabilitation, the University of Alabama at Birmingham,
victims such as Kemp are achieving recovery levels once thought
impossible. There,
psychologist Edward Taub has pioneered a simple but dramatic
approach. It's called CIM - constraint-induced movement therapy,
or, as some put it, tough love. The
therapy involves putting the unaffected arm in a splint for most
of a patient's waking hours for two weeks and getting the patient
to spend six hours every day using the bad arm in a series of
increasingly precise exercises. For the therapy to work, the
stroke survivor must have some control over the bad arm, such as
the ability to open and close the hand. To
the astonishment of many in the stroke rehabilitation field, this
approach seems to work, perhaps by rewiring parts of the brain or
spinal cord. "The
idea that people can still experience improvement in the use of
the affected side even years after their stroke, this is a
revolutionary concept," said Dr. Leonardo Cohen, chief of the
human cortical physiology section at the National Institute of
Neurological Disorders and Stroke. "The new approach, now
being studied across the country, provides for the first time a
treatment alternative for stroke patients, at a time when it was
thought there was no treatment." One
scientist who is not surprised at the way the new therapy is
catching on is Taub. Back in the 1970s, Taub began working with
monkeys who had had the sensory nerves surgically cut in one arm,
but not the motor nerves. The monkeys could feel nothing in the
bad arm, but the nerves that control movement were still intact. Typically,
Taub said, the monkeys learned that the bad arm was useless
because they couldn't feel anything. They'd try to move that arm,
fail, and soon stop trying, a lesson that Taub calls "learned
non-use." But,
when he put a straightjacket on the monkey's good arms, the
results were remarkable. The animals started using their bad arms
within two hours, Taub said, and, after just a week of training,
used them fairly normally for the rest of their lives, even when
their nerves had been injured as long as four years before
treatment. Recently,
Taub and others have achieved similar results in people up to 21
years after they have survived strokes. So far, the method has
been tried in about 200 patients. In
research published in June in the journal, Stroke, Taub, working
with a German team led by Dr. Joachim Liepert, studied 13 people
who had had strokes at least six months earlier and found that
they were able to regain75 percent of their arm movement with
constraint-induced movement therapy. Moreover,
a brain-mapping technique called Transcranial Magnetic
Stimulation, or TMS, showed that, after constraint therapy, the
part of the brain that controls the stroke-affected arm doubled in
size, getting back nearly to normal. That
suggests that the damaged part of the brain might actually be
coaxed to work again. In addition, the constraint therapy seems to
boost activity in the side of the brain that does not control the
paralyzed limbs. (Normally, the right side of the brain controls
the left side of the body, so a stroke in the right brain may
paralyze the left arm and leg.) That suggests that, for a person
who had a stroke in the right brain, the left brain might be
coaxed to take over the right's work. TMS
does more than just show scientists what's going on in the brain.
It can also be used to change the pattern of electrical activity
in parts of the brain, a technique that has already been used to
treat severe depression. In
TMS, a coil of wire is placed on the head and an electrical
current is passed through the wire in a rapid on-off pattern. That
triggers a brief magnetic pulse that excites nerves in a specific
region of the brain. Depending on how rapidly the current is
turned on and off, the magnetic pulse can either increase or block
nerve activity in the targeted brain area, explained Dr. Alvaro
Pascual-Leone, director of the laboratory for magnetic brain
stimulation at Beth Israel Deaconess Medical Center in Boston. This
suggests that, perhaps even without constraint therapy, TMS could
be used to rewire the brain and restore movement to paralyzed
limbs, though this has not yet been shown. And there's one big
caveat: Scientists must learn to control TMS sufficiently so that
they don't inadvertently block nerve activity where they're trying
to increase it. "That could actually make the outcome
worse," Pascual-Leone said. For
the immediate future, though, constraint therapy is grabbing the
attention of patients and researchers, even though most insurers
do not yet cover the technique. At
the National Institute of Neurological Disorders and Stroke, Cohen
is analyzing the results of a controlled trial to see whether the
constraint therapy is superior to conventional therapy, in which
the patient is relatively passive and the therapist moves the
patient's paralyzed arm or leg. At
Emory University in Atlanta, neuroscientist and physical therapist
Steven Wolf has begun enrolling 240 patients at seven medical
centers around the country in a constraint therapy study called
the EXCITE trial. Like
Taub's monkeys, people learn not to use their weak arm or leg
after a stroke, Wolf said, a problem made worse by the trend
toward shorter hospital stays. Instead of being hospitalized for
months as patients once were, most stroke victims are out in 14
days, which means "about the only thing a rehabilitation
specialist can do is train people to get from the bed to the
wheelchair," he said. "That reinforces the notion of how
not to
use the impaired arm." In
Boston, Judith Schaechter, who is both a neuroscientist and a
physical therapist, has tried constraint therapy on four patients
at Northeastern University. All four made clear gains, said
Schaechter, who has moved her research to Massachusetts General
Hospital. One
of her patients, Richard Mahoney, a 54-year-old Boston man who had
a stroke last summer, barely used his right arm before constraint
therapy. The treatment "helped me immensely," he said.
Now he uses his right hand all the time. And
Fred Kemp? After only three days of constraint therapy, he was
able to open a refrigerator door with his bad left hand without
having to think much about it. "I know I can open it. I
couldn't before." The therapy is rigorous, he added. But it's
"going to be worth the effort to me to get something
back." For more information on constraint-induced movement therapy, call: ·
The
University of Alabama at Birmingham, Taub Training Clinic,
at205-975-9799. ·
The
EXCITE trial, headquartered at Emory University, at 404-712-2222. ·
Behavioral
Neurorehabilitation Unit, Beth Israel Deaconess Medical Center, at
617-667-4074. Judy
Foreman is a Lecturer on Medicine at Harvard Medical School. Her
column appears every other week. Past columns are available on www.myhealthsense.com.
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