New Techniques Stimulate Stroke Recovery
“Have you ever tried to read a newspaper with one hand?” asked Leslie McClellan. The 68-year-old man from Gainesville, Fla., knows that it’s truly an exercise in frustration.
Reading a newspaper is just one of life’s daily activities that is a challenge for the two-thirds of the 4 million American stroke survivors who are left physically impaired. (Former President Gerald R. Ford suffered what was called a small stroke Wednesday, but doctors said he does not seem to be significantly impaired).
Many stroke patients find that buttoning a shirt, preparing and eating a meal and driving a car are among the things that have to be relearned.
But researchers have developed two new techniques for stroke rehabilitation. Each is designed to restore function to a disabled arm by training the brain to send it certain signals.
The techniques, according to the researchers, seem to strengthen and reorganize the portion of the brain damaged by stroke. Both therapies support emerging brain research suggesting the adult brain remains much more plastic, or able to reorganize and renew, than was previously thought.
Until now, the predominant therapy for stroke victims has been to teach them how to compensate for the loss of a limb by using the uninjured one.
Recent findings suggest that the two new techniques--called constraint-induced movement therapy and muscular-triggered electrical stimulation--can restore a substantial amount of movement to the damaged limb, even years after a stroke.
McClellan, for example, was impaired for four years before electrical stimulation improved the functioning of his left arm so much that he returned to work part time.
“It’s changed my whole life,” he said. “Driving a car is so much easier, using the turn signals, holding a newspaper . . . I’m doing all of it, not real well yet, but I can [do it]. Out of all the different therapies I’ve had, this one has helped the most. You’d be amazed at what you can do.”
Like McClellan, most patients have been told that if they do not recover movement in a limb in the first year after a stroke, they are unlikely to ever regain it. But the new treatments are overturning that prognosis.
“Some time ago someone told them, ‘You’re not going to be able to move your arm again,’ and to see them do some extension, they were just so excited and motivated. As a researcher, it’s very gratifying to help just a little bit in this kind of situation,” said James Cauraugh of the University of Florida, who pioneered a study on electrical stimulation treatment.
Cauraugh and his colleagues used a device called the AutoMove AM800 to help patients complete extension exercises of their wrists and fingers. Through electrodes placed on the arm, the device measures electrical impulses sent from the brain to the muscles and then sends back an electrical stimulation to the arm.
As patients concentrate on trying to extend fingers, a weak impulse is sent from their brain to the arm muscle. If they focus enough to reach the preset electrical threshold, then the device sends a small electrical stimulus to the muscle to help complete the movement. “It’s like when you take a jump shot and you just know it’s going to be a swish,” Cauraugh said. “These people haven’t felt that sensation of movement in this limb in a very long time.”
After 12 sessions of 30 attempted extensions, patients receiving the experimental treatment doubled the number of blocks they could move in 60 seconds with their affected hand. The control group, which completed the sessions without any electrical stimulation, did not show significant improvement. AutoMove has been approved by the Food and Drug Administration for stroke rehabilitation, and its maker, Stroke Recovery Systems Inc., estimates that 1,000 to 2,000 patients in the U.S. have prescriptions to use it at home. (Patients with pacemakers are advised to have their cardiologist supervise the first use of the device but, so far, no major complications have been reported, according to company spokesmen.)
Constraint-induced movement, or CI therapy, also aims to gain reuse of a disabled limb. The technique restricts use of the good arm by placing the hand in a protective mitt. This forces the patient to use the stroke-affected limb during hours of repeated activities in therapy and for most daily activities at home for two weeks.
“[By] picking up marbles and pennies, and threading a hole with shoelaces, my brain started reconnecting that I had a left hand and I was supposed to start using it again,” said Jesse Reed, 67, of Birmingham, Ala., who had a stroke almost six years ago.
“The important thing is not so much the task, but the repetition of the task, called massed practice, over many hours a day over consecutive days. You must use the arm over and over again [to produce brain] reorganization,” said psychologist Edward Taub, who leads studies of CI therapy at the University of Alabama at Birmingham.
Counting beans, playing a board game or screwing a nut onto a bolt, when repeated exhaustively, allows the brain to re-form the lost connection to muscles. Taub reports that age and the number years after a stroke do not appear to be factors in the effectiveness of CI therapy. It has been implemented in patients who suffered a stroke up to 21 years before and in patients in their 80s.
The Alabama group published a study in June describing how CI therapy might reorganize the brain. Using imaging technology, they mapped the areas on both sides of the brain responsible for movement of the right and left thumb muscles.
On the stroke-affected side, the brain area was significantly smaller than on the unaffected side. But after two weeks of CI therapy, the area on the affected side had enlarged to the same size as the unaffected side, and remained so for up to six months.
Therapies Need Large Trials
These therapies might one day also be used to treat other types of brain and spinal cord injuries. For now, though promising, they still remain to be proven for use in stroke rehabilitation by large nationwide trials.
USC will be one of five U.S. sites to participate in a 240-patient, four-year clinical trial of CI therapy.
These large trials will determine not only the effectiveness of the therapies, but also which patients are appropriate candidates for them. Researchers and therapists caution that these therapies are not for all stroke patients, especially those with full paralysis or cognitive impairments.
Dr. Alexander Dromerick, medical director of stroke rehabilitation at Washington University in St. Louis, cautions: “These are incremental improvements, not major breakthroughs. [CI therapy] should not be substituted for conventional therapy.”
In contrast, patients see these incremental changes as personal triumphs. “Before, I couldn’t do anything; my left arm was [curled] at my chest, frozen in place,” said Reed. “Now, I can wash dishes, eat with my left hand, pick up a glass and get water, swing a golf club; it’s just amazing. It’s just small things that may be insignificant to someone who has full use of their body, but to me, one inch is a milestone.”
McClellan and Reed credit their successes to positive attitudes about the hard work of rehabilitation and to the caring but sometimes drill sergeant-like therapists who helped them. Reed warns against complacency: “Just don’t sit down. That chair will kill you.”
The University of Alabama has a hotline for inquiries about CI therapy: (205) 934-9999.
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Kendall S. Powell can be reached at kendall.powell@latimes.com.
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New Stroke Therapies Researchers are testing two new rehabilitation techniques with stroke survivors who have lost at least the partial use of an arm. Both methods are aimed at teaching the brain to relearn, or reconnect, the signals between nerves and muscles in the arm and hand--even years after a stroke.
THE MUSCLE-BRAIN CIRCUIT
Normal Circuit
1. When a person thinks about moving an arm, an impulse is sent from the brain’s motor cortex, which controls movement.
2. The impulse travels through one nerve pathway down the arm and tells the muscles to contract or relax.
3. Moving the arm sends sensory signals back to the brain on another path to tell it that movement was completed.
This circuitry can be disrupted by a stroke, which is caused by reduced or blocked blood flow to the brain, usually the result of a blood clot. A stroke usually affects one side of the brain, which controls movement of the opposite side of the body.
THE TWO TECHNIQUES
Constraint-Induced Movement Therapy
1. Use of the patient’s unaffected arm is restricted by a sling or with a protective mitt for 90% of waking hours for two weeks.
2. With a therapist for six hours each day, the patient must do repeated tasks (counting beans, threading a needle, undoing locks) with the affected arm and hand.
Muscular-Triggered Electrical Stimulation
1. A device attached to the affected arm measures tiny impulses sent by the brain as the patient tries to extend the hand.
2. The device detects when the patient’s brain has produced the maximum impulse possible. It then sends additional electrical stimulation to help the arm muscle complete the movement. The device resets itself to make the patient work harder for the next attempt.
3. The patient repeats this exercise 30 times in one session and completes 12 sessions over six days.
Sources: University of Florida, University of Alabama at Birmingham, American Stroke Assn.
