FRIDAY, March 1, 2002 (HealthDayNews) -- From the moment a stroke hits, the human brain is in deep trouble. As the seconds tick by, the risk of permanent damage shoots up.
Now, after years of fruitless research, scientists hope to confirm that they've finally found a way to protect the brain before a person even reaches the hospital.
While the results are preliminary and limited to a small number of people, a study in Los Angeles seems to support the use of magnesium sulfate by paramedics on the scene of a stroke.
The drug appears to "freeze" the brain until doctors can go to work, says study co-author Dr. Jeffrey L. Saver, a neurologist and co-director of the UCLA Stroke Center.
"These are these are very encouraging results. There's a strong suggestion that the drug is having a positive effect," he says.
A stroke occurs when blood flow to the brain becomes disrupted. About 600,000 strokes are reported in the United States each year, and 160,000 people die from them, according to the American Stroke Association.
Doctors do have one major drug treatment for stroke. Tissue plasminogen activator (tPA) acts as a kind of drain opener, unclogging arteries that have been blocked by blood clots. However, hospital tests are required before the drug can be administered, and it loses effectiveness as the hours pass.
Doctors have studied dozens of drugs that seemed to hold promise as so-called "neuroprotective agents" that would safeguard the brain, Saver says. None have worked.
"This remarkably disappointing record of drug development has led a lot of people to think about what we might be doing wrong in human trials of these drugs," he says. "One major thing that prior trials have done wrong is give the drug too late. It works best in saving brain while there's still brain to save."
Researchers at UCLA decided to investigate what would happen if stroke patients received magnesium sulfate at the earliest possible moment after a stroke. To do this, they recruited paramedics in the Los Angeles area.
The researchers released their preliminary findings at a recent conference sponsored by the American Stroke Association.
From May 2000 to January 2002, Los Angeles paramedics treated 20 patients, aged 44 to 89, with magnesium sulfate. In consultation with UCLA experts, the paramedics generally administered magnesium sulfate within 23 minutes after arriving at a stroke scene. By contrast, emergency room doctors in earlier studies administered drugs two to almost three hours after paramedics showed up.
Five of the patients appeared to respond to the drugs in the ambulance, Saver says. After three months, 12 of the subjects were in good shape.
The researchers didn't compare their results to a "control group" of patients who didn't receive magnesium sulfate. Those comparisons will come in a future study with a much larger base of patients, he says.
Unlike other drugs used on stroke victims, magnesium sulfate is generally harmless, regardless of what kind of stroke a person is suffering, Saver says.
In addition, the drug should not hurt people if a paramedic misdiagnoses a stroke victim. In fact, magnesium sulfate may actually help people who have conditions that mimic strokes, such as seizures and migraine headaches, he adds.
The drug appears to work by dilating blood vessels in the brain, allowing more blood to flow to threatened areas, Saver explains. It also blocks the dangerous influx of calcium into nerve cells that aren't getting enough oxygen.
Dr. James Grisolia, a neurologist with Scripps Mercy Hospital in San Diego, says the Los Angeles study is too small and limited to prove that magnesium sulfate is beneficial for stroke patients. However, he says, the researchers did show something important -- that you can treat stroke patients before they get to a hospital.
The study "is carrying the battle to save brain cells outside the emergency room, literally 'taking it to the streets' to get closer to onset, and save brain cells before their injury becomes irreversible," he says.
What To Do
Learn more about strokes from the American Stroke Association.
Magnesium sulfate is already used to treat problems during pregnancy. Learn about its uses and side effects.
