For Stroke Patients, Brain Can Learn New Ways

By challenging healthy people to learn unfamiliar, hand-dependent tasks, scientists are learning how patients overcome debilitating brain injury following a stroke, say researchers at the Radiological Society of North America meeting.

The research may also yield better therapies for stroke victims, the scientists say.

As the researchers watched on real-time imaging machines, the brains of study participants lit up in key areas as they learned to manipulate a computer cursor while wearing a hi-tech "cyberglove."

"We're looking to see which areas of the brain are involved in this process, and what happens in areas of the brain as this learning process goes along," explains lead researcher Dr. Kristine Mosier, a professor of radiology and neuroscience at Indiana University School of Medicine.

According to Dr. Mosier, her team's research could improve post-stroke rehabilitation by "giving us a better idea of whether a particular type of therapy is going to be effective, or whether some other type of therapy might work even better."

Stroke a Leading Cause of Disability

Stroke, which occurs when blood flow to the brain stops, remains one of the leading causes of death and disability in the US. Each year, stroke leaves thousands of Americans unable to move, speak, or swallow due to damage in specific brain areas.

Four million Americans are living with the effects of stroke, and the length of time to recover depends on its severity. Fifty percent to 70 percent of stroke survivors regain functional independence, but 15 percent to 30 percent are permanently disabled, according to the National Institute of Neurological Disorders and Stroke.

But the brain retains an amazing facility to adapt and change in the event of a stroke.

"One of the areas that's been a center of research over the past few decades is to see whether or not parts of the brain can 'pick up' the function that was previously carried out by the now-dead neurons in the stroke-affected area," notes Dr. Mosier.

Remapping the Brain and Its Functions

In studies with 17 healthy adults, Dr. Mosier's team tried to simulate the challenges of what is called brain "mapping," the process by which the brain adapts to new, unfamiliar tasks.

Brains "map" out new tasks from birth as we learn to grasp, walk, or speak - matching up sensory input from the environment with coordinated muscle movements.

Dr. Mosier point out that stroke victims have to go through what is called "remapping" if they hope to regain lost function, since brain areas that coordinated those tasks in the past may be useless now.

In their lab, Dr. Mosier's team hooked up the 17 participants to functional magnetic resonance imagery (fMRI) - MRI scanning that shows real-time brain activity. The participants were then fitted with special computer-linked "cybergloves" that registered joint movements at 19 different points.

Specific combinations of finger movements allowed the participants to move a cursor on the computer screen. Normally, computer users rely on a mouse or touch pad to move a cursor, but in this case the participants had no such luxury.

"In that sense their brain is learning to remap," Dr. Mosier says. "It sounds very simple, but it's actually very difficult because their hand is not physically connected to the cursor on the computer screen."

All the participants eventually mastered this new, finger movement-dependent method of moving the cursor. And as they did so, specific neurological areas "lit up" as their brains came up with new ways to perform an otherwise familiar task.

"Areas that control hand movement are involved, of course, and you also see areas more toward the anterior part of the brain that we know are involved in learning," says Dr. Mosier.

The research is providing important clues to what might happen in similar circumstances in stroke-affected brains.

"It helps answer questions like, 'Which areas of the brain are involved in which activities, and do they change over time?'" Dr. Mosier explains. "This gives us a good way to predict, say, if you have a stroke affecting such-and-such area of the brain, how might other areas of the brain compensate for that."

The goal, Dr. Mosier says, is better post-stroke therapies tailored to specific patterns of stroke injury.

Always consult your physician for more information.

Online Resources

American Heart Association

American Stroke Association

Centers for Disease Control and Prevention (CDC)

Go Red for Women Campaign, AHA

HealthierUS.Gov

National Heart, Lung, and Blood Institute (NHLBI)

National Institute of Neurological Disorders and Stroke

National Institutes of Health (NIH)

National Library of Medicine

US Health and Human Services

January 2005

For Stroke Patients, Brain Can Learn New Ways

Stroke a Leading Cause of Disability

Remapping the Brain and Its Functions

Impact of Stroke

Online Resources

Impact of Stroke

According to the American Stroke Association (ASA), every 45 seconds, someone in US has a stroke.

Every three minutes, someone dies of one.

Stroke killed an estimated 163,538 people in 2001 and is the nation's third leading cause of death, ranking behind diseases of the heart and all forms of cancer.

Stroke is a leading cause of serious, long-term disability in the US.

In 2004 the estimated direct and indirect cost of stroke is $53.6 billion.

The ASA reports that each year about 700,000 people experience a new or recurrent stroke.

About 500,000 are first attacks, and 200,000 are recurrent attacks.

From 1991 to 2001 the death rate from stroke declined 3.4 percent, but the actual number of stroke deaths rose 7.7 percent.

Each year about 40,000 more women than men have a stroke.

Because women live longer than men, more women than men die of stroke each year.

Women accounted for 61.4 percent of U.S. stroke deaths in 2001. 

The 2001 death rates per 100,000 population for stroke were 56.5 for Caucasian males and 85.4 for African-American males; and 54.5 for Caucasian females and 73.7 for African-American females.

About 4.8 million stroke survivors are alive today. In 1999, more than 1.1 million US adults reported difficulty with functional limitations, activities of daily living, etc., resulting from stroke. 

From the early 1970s to early 1990s, the estimated number of noninstitutionalized stroke survivors increased from 1.5 to 2.4 million.

In the National Heart, Lung, and Blood Institute's Framingham Heart Study, among ischemic stroke survivors who were at least 65 years old, these disabilities were observed at six months post-stroke:

• 50 percent had some one-sided paralysis    
  
  
• 30 percent were unable to walk without some assistance
  
  
• 26 percent were dependent in activities of daily living (grooming, eating, bathing, etc.)
  
  
• 19 percent had aphasia (trouble speaking or understanding the speech of others)
  
  
• 35 percent had depressive symptoms
  
  
• 26 percent were institutionalized in a nursing home
  

Always consult your physician for more information.