Stroke rehab: Some hearty news

Greetings to my colleagues in the Philippine Academy of Rehabilitation Medicine, who are attending the 22nd Annual PARM National Convention at the Manor Hotel in Camp John Hay, Baguio City, on February 9-12.

Every year in the Philippines, thousands of Filipino men and women survive a stroke  the sudden interruption of blood supply to a part of the brain, which results in the death of brain cells. Rapid diagnosis and brain-sparing treatments  such as tissue plasminogen activator (tPA), an enzyme that dissolves blood clots, or other clot-clearing procedures  can help limit the damage and resulting disability. But the cells that do die can rob a person of her ability to speak, move, feel, think, or even recognize friends and relatives. About two-thirds of stroke survivors must work to regain abilities  or learn to compensate for the ones they can’t regain by developing new strategies.

Which parts of the brain are involved?

The effects of a stroke depend on which parts of the brain have been damaged (see illustration on Page D-2). For example, cell death in the cerebellum (the lower part of the brain) can throw off balance, posture, and the orchestration of voluntary muscle actions such as those required for walking or picking up a package. Damage to Broca’s area, in the frontal lobe and in the left side of the brain for most people, prevent a person from producing articulate speech, even if he or she understands what’s being said or knows what he or she wants to say. If there is damage to Wernicke’s area (in the left temporal lobe), the person doesn’t understand language even though he/she can articulate words. Generally, a stroke in one hemisphere of the brain interferes with functioning on the opposite side of the body. For example, a right hemisphere stroke might impair the left side of your field of vision (in both eyes) or might make it difficult to lift your arm or smile with the left side of your mouth.

Depending on its location in the brain, a stroke may produce one or more of the following:

• Paralysis or weakness on one side of the body (called respectively, hemiplegia or hemiparesis); spasticity (involuntary muscle tightening) that results in a stiff leg or a stiffly flexed elbow and wrist and tightly clenched fist; trouble swallowing (dysphagia); and difficulty coordinating movement (ataxia),

• Sensory changes, such as numbness, aches, and ongoing pain.

• Trouble understanding speech (receptive aphasia) or expressing oneself in words (expressive aphasia).

• Cognitive problems such as impaired thinking or memory; shortened attention span; disorientation; inability to recognize faces (prosopagnosia) or work step by step through a task (apraxia); and unawareness or denial of disabilities caused by the stroke (anosognosia).

• Emotional turmoil, such as changes in mood and personality, impulsivity or inappropriate behavior, and bursts of anger. In particular, about 25 percent of people who have a stroke develop major depression, which can undermine rehabilitation and worsen cognitive abilities, if untreated.

Early recovery and rehabilitation

After a patient is medically stable (usually within 24 to 48 hours), assessment of function begins. This may include tests of arm and leg strength, memory and comprehension, ability to speak and swallow, and others. Because numerous impairments may be involved, rehabilitation is facilitated by a diverse team, which may include doctors specializing in physical medicine and rehabilitation (physiatrists), rehabilitation nursing, physical therapists, occupational therapists, speech-language pathologists, and others. Simple steps toward rehabilitation should be started early. Patients are encouraged to shift position frequently in bed and practice simple range-of-motion exercises for an affected arm or leg.

As swelling in the brain subsides, oxygen-rich blood may once again reach temporarily compromised vessels and replenish the area they supply. Natural mechanisms begin repairing damaged tissue, and some degree of spontaneous recovery is likely in the first days and weeks.

Later, therapeutic plans will be tailored to individual impairments. Initial goals include sitting up and sliding from bed to chair, standing, and walking (with or without help), as well as ability to perform daily activities, such as dressing, bathing, and eating. Ultimate goals may include a return to work and pleasurable activities. Therapy may take days, weeks, or months.

Rethinking stroke therapy

Until recently, scientists thought that when a region of the brain is damaged, its function was lost forever. Stroke patients who couldn’t use a weak or paralyzed arm were taught to dress and bathe with their good arm. But sophisticated imaging tests of the brain at work have since revealed that it can reorganize itself after injury so that when nerve cells die, their functions are taken over by other cells.

The concept  known as neuroplasticity  has altered stroke rehabilitation considerably. “Now, we know that if you want to get motor recovery on the affected side, you have to use the affected side  repetitively and intensively,” says Richard Zorowitz, MD, chief of physical medicine and rehabilitation of Johns Hopkins Bayview Medical Center in Baltimore. “That stimulates the brain to make those new connections.”

Neuroplasticity is the principle behind new techniques such as mirror therapy (see photo above) as well as several other new technologies. Those include electrical stimulation of the damaged limbs and robots that help patients repeatedly move those limbs.

Advanced technologies

• Restrain yourself. Some rehab therapists are also using constrained-induced movement therapy (CIMT), an increasingly popular approach that forces the use of a patient’s impaired limb  usually an arm  while restraining the unaffected one. In a 2006 trial funded by the National Institutes of Health, 222 stroke patients were randomly assigned the usual care or CIMT, in which they wore a restraining mitt on their good hand most of the day for two weeks, and did repetitive tasks with their affected hand for up to six hours a day. People in the CIMT group made significantly greater gains in arm movement that persisted a year later, the researchers found.

While CIMT is most effective when it’s started soon after a stroke, it can even help patients who had strokes years earlier. A study of people who had the therapy more than four years after the attack, for example, found that it not only improved the use of their weak arm but also doubled the amount of activity in the region of the brain that controls its movements.

• Robotics. Advances in robotics are also providing new options in stroke rehabilitation treatments. One device, called the Lokomat, is a set of robotic leggings that puts the legs through walking motions while the patient is on a treadmill and supported by a padded harness (see photo on Page D-1). Another device, the Myomo e100 NeuroRobotic System, is a brace wired to pick up weak signals from the patient’s arm muscles and respond by bending or extending the arm. “It’s sort of like power steering,” says Dr. Joel Stein, chief medical officer at Boston’s Spaulding Rehabilitation Hospital. Stein is the lead author of a pilot study of the device published recently in the American Journal of Physical Medicine and Rehabilitation. “You plan the movement, you execute it, but the brace helps you do it,” he explains. By practicing with this device, stroke survivors can often relearn arm movements and strengthen the brain pathways that govern these movements.

Other promising research combines intense, repetitive exercise with electrical or magnetic stimulation of the brain aimed at boosting plasticity. On the basis of preliminary studies in animals and humans that suggest these methods can speed neural rewiring, trials of several brain stimulation devices are under way.

Extending the therapeutic window

People recovering from a stroke make their greatest gains in the first three to six months. That’s one reason it’s essential to advocate  for yourself or a loved one  for early rehabilitation. At the same time, research suggests that improvements may occur for many months and even years beyond this window.

Stem cells, growth factors, and other agents that could help in rebuilding injured areas of the brain are being investigated. Such developments are likely to be years away, but many smaller advances that can make a tremendous difference in a stroke survivor’s life  such as stronger and better coordinated hand movements, a more natural walk, or more comprehensive speech  are available today.