ANAHEIM, Calif., Feb. 6 -- A new three-minute screening test that detects one-sided motor paralysis allows paramedics and other first-responders to rapidly identify people experiencing a stroke, and may soon enable on-the-scene treatment with drugs that can limit the potentially extensive damage caused by these "brain attacks," Los Angeles researchers reported here today at the American Heart Association's 22nd International Joint Conference on Stroke and Cerebral Circulation.
Jeffrey Saver, M.D., neurology director of the stroke center at the University of California, Los Angeles, and one of the developers of the test, said, "Paramedics are the first to arrive, so they are the best people to identify a stroke in progress and initiate treatment. During stroke, time is brain, and the sooner treatment begins the better the chance of reducing permanent damage. Patients with motor paralysis are the stroke victims most likely to be disabled by their stroke, and therefore most in need of early rescue therapies."
According to the American Heart Association stroke is the leading cause of serious long-term disability in the United States, accounting for half of all patients hospitalized for acute neurological disease. It strikes an estimated 500,000 Americans annually and also is the third leading cause of death. Almost four million stroke survivors are alive today.
But, Saver explained, only about five percent of stroke patients reach the hospital in time to be treated with the clot busting drug TPA. First used to treat heart attacks in progress, TPA is the only approved treatment for acute ischemic stroke, which accounts for about 80 percent of all strokes and is caused by blood clots that reduce the flow of blood, oxygen and nutrients to the brain. But the drug must be used within three hours of the onset of stroke symptoms. Swift diagnosis in the field could allow more patients to reach the hospital within that window of opportunity.
The paramedic asks five questions designed to identify individuals with seizures or other disorders similar to stroke. If the individual does not have one of these other disorders, he or she undergo the screening procedure, which involves a series of motor function exercises. These include smiling and lifting each arm for five seconds. These tests are then repeated.
Chelsea Kidwell, M.D., clinical instructor at the UCLA Stroke Center, who presented the findings today, said, "It's a very simple test but it can identify a great number of patients experiencing stroke."
The study involved 47 patients who were enrolled in clinical trials on stroke treatments during the last three years at UCLA. All of them underwent a form of the screening test during their initial emergency room evaluation. These test results were later compared with further diagnostic evaluation of stroke, such as computed tomography X-ray scans of the brain.
Forty of the 47 patients were diagnosed with ischemic strokes and 93 percent would have been identified by the new screening test, which is now called the Los Angeles Paramedic Stroke Screen.
Another outcome of the study was that the screening test can shorten time to actual treatment by an average of 90 minutes, Kidwell said.
The clinical trials the patients were part of involved the use of drugs called neuroprotective agents, which help protect brain cells when loss of blood causes cell death and the attendant release of toxins that cause further destruction.
Currently, treatment for a person strongly suspected of having a stroke, or "brain attack," is delayed by time-consuming ambulance transport, emergency room evaluation and computed tomography X-ray scanning. Thus, the scientists said, a reliable paramedic screening instrument that can reduce the time to treatment would greatly benefit thousands of stroke patients.
Shortening time to treatment also means educating people about the warning signs and symptoms of stroke, and getting medical systems to mobilize resources for prompt therapy, Kidwell said.
The next step will be to train paramedics to deliver neuroprotective agents at the scene. Unlike TPA, which can be dangerous if given to a person with a hemorrhagic stroke, some neuroprotective agents are relatively safe to initiate before a brain computed tomography scan. But, they, too, must be administered soon after stroke symptoms begin -- usually within three to six hours.
Co-authors of the study are: Sidney Starkman, M.D., and Glenn Schubert, M.P.H.