Study Shows Treatment for Stroke Symptoms Possible
For the first time, a study has shown that it’s possible to reduce the damage strokes cause.
But experts aren’t yet ready to recommend it for widespread use because the treatment involves a perilous balance between risks and benefits.
The medicine is tissue plasminogen activator--TPA--a genetically engineered protein that is already a mainstay of heart attack therapy.
About 500,000 Americans suffer strokes annually. They are the leading source of adult disability and the No. 3 cause of death after heart disease and cancer. Until now, there has been no proven treatment to limit the damage in the first hours after a stroke occurs.
A European team reported Friday that TPA significantly reduces the amount of brain injury resulting from strokes if given quickly after the onset of symptoms--but only when reserved for a carefully selected group of patients, probably half to three-quarters of all stroke victims.
The difficulty of identifying these patients is likely to curtail its widespread use, at least until experts sort out better guidelines for emergency-room doctors.
The dilemma for doctors is simple: If given to the right patients, TPA can prevent a lifetime of paralysis and other crippling disabilities. If given to the wrong ones, it can trigger bleeding in the brain that makes the effects of a stroke even worse.
“The patients who we really want to treat benefit a lot. Treating those who we don’t want to can be a disaster,” said the study’s director, Dr. Werner Hacke of the University of Heidelberg in Germany.
The study was conducted on 620 stroke patients who were given TPA within six hours of the start of their symptoms. The results were released at a stroke conference sponsored by the American Heart Assn.
Most strokes occur when a blood clot lodges in the brain, cutting off circulation. However, about 20% result when a blood vessel bursts. TPA is a natural protein that works by dissolving clots.
In their study, the doctors intended to treat only those whose strokes resulted from clots. They performed CT scans first and excluded patients whose strokes had already resulted in large areas of dying brain tissue.
When they studied the 511 patients who met these criteria, TPA was clearly beneficial. While their death rate was about the same, they suffered less brain damage. Forty-one percent of them suffered little or no lingering effects from their strokes, compared with 29% who got placebo injections.
