Methylprednisolone, the first drug ever to demonstrate effectiveness against crippling spinal cord injuries by reducing paralysis, has become standard treatment in the nation's emergency rooms.

When it was introduced at a news conference last April the steroid, which must be administered within eight hours of injury, got off to something of a rocky start. The National Institute of Neurological Disorders and Stroke, which funded studies of the drug, announced results showing that 162 patients treated with it suffered significantly less paralysis than did 325 others who were treated with another medication or a placebo.

But the agency, which recommended that doctors immediately begin using it, did not provide emergency room physicians with enough information. As a result, many hospitals initially hesitated to use the drug immediately.

One month later, the study was published in the New England Journal of Medicine and since then use of the drug has become widespread, according to Wise Young, a neurologist at New York University Medical Center and one of the authors of the journal article.

Before methylprednisolone, doctors were powerless to prevent paralysis after a spinal injury, which occurs about 10,000 times annually. Physicians have known for a decade that it is not the injury itself, but the body's reaction to it -- chiefly in the form of swelling and the formation of scar tissue that kills nerve cells -- that inflicts the most damage.

The drug, which was previously used to prevent swelling after surgery or a stroke, protects nerve cells while the injury heals. It permits patients to function at a level about 20 percent greater than would be the case without treatment.

"That 20 percent may mean different things to different people," Young said. "For some patients, this means the difference between being able to wheel their wheelchairs. For others it may mean they can feed themselves or drive, and in some people it's going to mean they're going to walk." The effect of the drug appears to be long-lasting, doctors report.

The price has dropped and treatment now costs about $200 or less. One-year results of the clinical experience with the drug should be published soon, Young said.

The success of methylprednisolone holds promise for the development of other compounds that will be more effective in preventing virtually all paralysis resulting from spinal injury, he added.