KISSIMMEE, FLA. ? Like pouring Drano directly on a clog, doctors dramatically improved stroke survival by dripping a clot-dissolving drug right onto a blockage choking off the brain’s blood supply.

Many patients given this experimental treatment had stunning recoveries within a day, often without the speech loss and paralysis that can follow a stroke, doctors reported Thursday.

A second study found that people given the treatment were 65 percent more likely to be able to walk, talk and function normally three months after their strokes than those given standard care.

“We’re very encouraged by these results,” said that study’s leader, Dr. Joseph Broderick, neurology chief at the University of Cincinnati. “We found that we were either partially or completely able to open the blocked artery 69 percent of the time.”

The promising results from the two small studies were presented at a conference of the American Stroke Assn.

Strokes kill about 163,000 Americans each year and are a leading cause of long-term disability. Most are due to clots that deprive an area of the brain of blood, causing it to die.

The usual treatment is intravenous doses of the clot-busting drug, TPA. But it must be given within three hours of the start of symptoms, doesn’t always work and sometimes causes dangerous bleeding in the brain.

Doctors tested a novel way to give TPA to try to overcome these three problems. The method is similar to angioplasty, the procedure to open clogged heart arteries. A tube is inserted in a vessel in the groin and guided to the clot – in this case, in the head rather than near the heart.

TPA is dripped directly onto the clot through the tube instead of having to make its there through the bloodstream.

One-fourth of the 128 patients given this treatment in the last decade at the University of California at Los Angeles had dramatic improvement of stroke symptoms within a day, study leader Dr. Doojin Kim reported. Many others improved, too, but less dramatically.

About 90 percent survived, compared with 74 percent of stroke patients who get standard intravenous TPA. Bleeding in the brain also was less frequent with the novel approach.