Clot Solvent Shown to Reverse Massive Strokes

For the first time, doctors have shown that they can reverse massive strokes up to six hours after the start of symptoms by squirting a new clot-dissolving medicine directly into the brain.

The approach offers potentially better treatment for the worst strokes and doubles the time victims have to get help before they suffer permanent brain damage.

Doctors tested the medicine, prourokinase, on people who suffered a particularly serious form of the disease that accounts for about one-third of the estimated 600,000 strokes treated in the United States annually.

“If you have a massive stroke, this gives you the best chance of a decent outcome,” said Dr. Steven R. Levine of Detroit Medical Center, who was not involved in the study.

Until two years ago, strokes were untreatable in the hours immediately after they occurred. Then researchers discovered that TPA, or tissue plasminogen activator, already the mainstay of treating heart attacks, could also dissolve the blood clots that cause most strokes.

But research suggested that TPA can help only if given within three hours of the start of symptoms, such as numbness and difficulty talking, and brain scans are necessary to make sure the stroke truly results from a clot.