THURSDAY, Sept. 6, 2001 (HealthDayNews) -- Many of the 750,000 Americans who suffer a stroke each year will lose the power of speech, but new research suggests an unlikely drug may help victims find their voice again.
A University of Texas Southwestern Medical Center study finds that small doses of an amphetamine, coupled with speech therapy, may help stroke victims recover the ability to communicate more quickly and completely. The findings appear in tomorrow's issue of Stroke: Journal of the American Heart Association.
"This is the beginning of a number of studies that need to be done," says lead author Delaina Walker-Batson. "This implies that we could use it [the drug] to enhance recovery. This drug is an enabling influence helping plasticity. It may make new nerve connections or help ones that are not working."
While amphetamines have been used in stroke recovery for motor deficits, stroke expert Dr. Randolph S. Marshall says, "People have wondered if it would work as well on other deficits that can follow a stroke. It's not a completely surprising finding. It's additional evidence that we can enhance the brain environment, and that [enhancement] can help with stroke recovery."
The researchers looked at 13 men and eight women, aged 41 to 71, with aphasia, a condition in which the ability to speak or understand language is impaired or lost. Twelve patients received 10 milligrams of dextroamphetamine -- better known as Dexedrine -- and nine received a placebo. Both groups received the drug before 10 individual speech therapy sessions over five weeks. The one-hour therapy sessions began 30 minutes after the drug or placebo was given. Treatment began between 16 and 45 days after the strokes occurred. None of the patients showed any dangerous side effects, such as increased blood pressure, during the study.
One week after treatment ended, 83 percent of the dextroamphetamine group had surpassed the 15-point gain in speech skills set as clinically significant by researchers, while only 22 percent of the placebo patients had made the same progress. The dextroamphetamine group also made significant advances after six months.
Walker-Batson says the timing of the therapy was key, and the pairing of the drug with speech therapy was crucial.
"Timing is a real factor. There may be a critical period to go in and recruit these redundant pathways. We don't know the timing. There needs to be more exploration," she says.
And the drug does not do the job alone.
"It must be paired with therapy. There needs to be a lot of practice when you're trying to train neurons to do jobs they haven' t done before. It's not just a pill. It's what we call rehabilitative pharmacology," she says.
Walker-Batson says, "I'm surprised that with just 10 doses we got an effect." Future research will look at different dosages and drugs, different timings for treatment and larger groups of stroke sufferers, she says.
The researchers say dextroamphetamine encourages the release of noradrenaline, a messenger chemical in the brain that may stimulate areas of the brain damaged by stroke. Animal studies have found that noradrenaline does the same with the impaired motor skills, sensory deficits and visual problems that often follow stroke.
Marshall says most likely the drug activates the brain generally and makes it more amenable to therapy. "There's not good evidence that it grows new nerve connections," he says.
Every 45 seconds, someone in the United States suffers a stroke, and four of five families will be touched by stroke, reports the National Stroke Association. Stroke is the third leading cause of death in this country, killing almost 160,000 people a year. Roughly 4 million Americans are living with the damage caused by stroke, and the health-care costs total about $17 billion a year.
What To Do
Find out more about stroke from the National Stroke Association, the American Heart Association or the
National Institute of Neurological Disorders and Stroke.
