1999


From: Massachusetts General Hospital

Telemedicine can be used for accurate diagnosis of stroke symptoms

When a stroke cuts off the blood supply to the delicate tissues of the brain, time is one of the most crucial determinants of a patient's survival and overall outcome. It is so critical the neurologists use the phrase "time is brain" to stress the importance of rapid diagnosis and treatment to minimize the damage of a stroke. In a study in the October issue of Stroke, researchers from the Massachusetts General Hospital (MGH) show that new telemedicine technologies can be used to shorten the time required for an accurate stroke diagnosis, especially for patients in locations distant from major medical centers.

"There are two major challenges that lie in the way of patients getting optimum treatment for stroke," says Lee Schwamm, MD, the MGH neurologist who led the study. "One is increasing public awareness so that patients and their family members recognize the symptoms of a stroke [see note at end of release] and get to the nearest emergency room right away. The second challenge is bringing the specialized knowledge required to correctly apply the latest treatments for acute stroke into every emergency room in the country. With telemedicine links to tertiary care centers, smaller community hospitals - even those in isolated rural areas - can deliver state-of-the-art stroke care."

The outlook for patients with potentially disabling strokes has changed dramatically over the past few years with the introduction of thrombolytic or "clot-busting" drugs like tissue plasminogen activator (tPA) that can dissolve a blood clot lodged in the brain before brain tissue is permanently damaged. If appropriate treatment is applied soon enough, patients who might otherwise have died or been serious disabled can recover with few, if any, permanent disabilities.

But the safe application of these medications requires exquisitely accurate diagnosis. If a patient's stroke is caused by a ruptured blood vessel instead of a clot, or if too much time has elapsed since the onset of the stroke, using these medications can cause more harm than good, possibly even killing the patient. Some patient may require that medications be injected directly to the site of the clot, which would require their being transferred to a specialized stroke center. But if patients are good candidates for intravenous thrombolytic therapy, speedy treatment is essential and should be administered wherever the patient is.

Because physicians with the expertise to determine the best treatment options for stroke patients are primarily located in tertiary care hospitals, telemedicine - the exchange of data and information via electronic means to facilitate diagnosis and treatment - seems a logical way to bring that expertise into community hospitals. Indeed, Schwamm explains, that is already happening in a very low-tech fashion. "When I get a telephone call or faxes from a colleague seeking advice about how to treat a stroke patient that can't get to the MGH fast enough, that is telemedicine at its most basic level. How much better would it be if we could use the kinds of communication technologies now available to let physicians in my position actually see the patients, review their symptoms and, ideally, look at high-quality images taken on site?"

The current study was designed to see whether an established assessment of stroke symptoms could be performed through a telemedicine link as accurately as at the bedside. In order not to compromise the diagnosis of patients with acute stroke, the study enrolled 20 patients recovering from ischemic strokes - those caused by blockage of a blood vessel - at the MGH or Spaulding Rehabilitation Hospital. Each patient was examined twice using the standard National Institutes of Health Stroke Scale (NIHSS). In one instance, the patient was examined by a neurologist at the bedside. The other examination was performed by a neurologist communicating with the patient and a bedside nurse via personal computers with integrated video cameras, connected by standard high-speed data transmission lines. Neither neurologist had any prior knowledge of the study participants or of the results of the other physician's assessments.

Analysis of the two sets of examinations showed no significant differences in the overall results. Although the telemedicine exam took 3 to 5 minutes longer, the variations in NIHSS score (which reflects factors such as language, strength, sensation, vision and comprehension) between the bedside and telemedicine examinations were no different than would be expected between two different bedside examiners.

"Now that we have shown that you can accurately and safely make a diagnosis with this kind of link, the next step will be evaluating the technology in real-time diagnostic situations," says Schwamm. He adds that the kinds of video connections tested in this study are now becoming widely available through high-speed cable and other broad-band communications systems.

"This sort of system has the potential to collapse barriers of time and distance between patients and providers. Ultimately it could be brought into settings like doctor's offices, nursing homes or athletic facilities, bringing telemedicine into another level of reality."

Co-authors of the study are Saad Shafqut, M.D., PhD; Joseph Kvedar, M.D.; Mary Guanci, RN, MSN; and Yuchiao Chang, Ph.D., all of the MGH.

Note: for information on the warning signs of stroke, check the American Heart Association website at http://www.americanheart.org/Stroke/Warning_Signs/.




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