When Ruth Johnston got a crushing headache and started to slur words that morning on the sailboat, her husband took action. He radioed the Coast Guard that she was having a stroke.

Within 15 minutes, Maryland medics whisked the woman to North Arundel Hospital, where doctors started an IV with a clot-busting drug and sent her on, sirens blaring, to the University of Maryland Medical Center. In those few hours, the treatment stopped the massive stroke spreading across her brain. The only mark the attack left was an occasional cold tingling in her hand.But six years after the discovery of this stroke therapy, Johnston, 51, is among a relative few who happened to be in the right place at the right time. Most patients don't get to a hospital within the required three-hour window. Some doctors, worried that that the drug is too risky, are reluctant to give it. And hospitals are still wrestling with getting the staff and other resources needed to treat patients around the clock.

"The miracle cases are the exception. Most of the cases are the miserable cases," said Dr. Kieran Murphy, director of interventional neuroradiology at Johns Hopkins Hospital. He routinely sees patients who have been transferred from other hospitals too late to save them from a nursing home.

It's one of the oldest stories in medicine: Researchers come up with a breakthrough, but it takes years to figure out how to make it work at the local hospital. This week, neurologists, emergency-room physicians and others from around the country are meeting on the issue at the National Institutes of Health.

But solutions require answering tough questions, such as whether only certain hospitals should become stroke centers, how to pay for care, and why, after millions of dollars spent in media campaigns, the public isn't getting the message that a stroke is an emergency.

In Maryland, doctors are working on many fronts. They have spread the word on billboards and buses. The state's emergency system is developing a list of hospitals that can give advanced care, and starting in the summer, medics will reroute stroke patients to these facilities.

The University of Maryland's Brain Attack Center advises smaller, faraway hospitals, flies patients in by helicopter and has cameras in ambulances so neurologists can evaluate patients en route.

"The whole field is close to a revolution," said the center's director, Dr. Marian LaMonte, who has led the efforts.

Clot-busting drug

It has been a long time coming. For generations, doctors could do little for stroke patients. Then in 1995, a study showed that the drug t-PA, used to break up clots in heart attacks, also worked in strokes if administered quickly, reducing disability by a third. Neurologists were ecstatic. Some recall getting chills when they first gave the treatment and saw some stroke patients regain movement or speak again.

Over the past several years, the improvements neurologists expected for stroke - the country's No. 3 killer and a leading cause of disability - haven't panned out. Of the 600,000 Americans who have strokes every year, about four-fifths have the type of stroke that can be helped by t-PA. But experts say about 3 percent are getting the medicine.

Many of these patients recover fully or have less disability than they might have had without the medicine. A small number, though, have suffered brain hemorrhages and died, provoking debate over whether the drug is safe, or whether some physicians are giving it wrong.

"Everyone assumed, `Hey, we've got a treatment for stroke now,' " said Dr. Eric Aldrich, an assistant professor of neurology at Hopkins. "But it's turned out to be much harder than anyone ever anticipated."

For starters, many people ignore common stroke symptoms, or wait hours and sometimes days before going to a hospital. Others suffer a stroke in their sleep, and it's difficult to determine what time it happened.

At the hospital, physicians must distinguish a stroke from other conditions that mimic it, such as seizures or complicated migraines, but they don't have quick, reliable tests - such as monitors or blood work that help verify heart attacks.

Because the clot-busting drug can cause bleeding in the brain, doctors must do a CT scan to make sure the patient doesn't have the type of stroke, known as hemorrhagic, in which a blood vessel bursts.

But at night, many smaller hospitals don't have the technicians or specialists to do the scans. Nor do they have neurologists who can race in with the expertise to diagnose a stroke and approve the patient as a candidate for the drug.

And all this has to be done within three hours. That's because by then, brain tissue has begun to die, and there is little chance of reversing damage - and some think the threat of bleeding is greater.

'Incredibly lucky'