Researchers believe that someday, doctors may be able to use specially-equipped laptops and smartphones to figure out if sudden-onset dizziness in patients is the result of a stroke, or of a (more likely) benign disturbance in the inner ear.
If scientists can prove that the technology works dependably, said Johns Hopkins neurologist and ear, nose and throat specialist Dr. David Newman-Toker, the devices could potentially prevent 100,000 misdiagnosed strokes every year by augmenting the methods emergency rooms currently use to figure out what's going on. The machines could also save money, by reducing the number of expensive CT scans given to patients.
"We're spending hundreds of millions of dollars a year on expensive stroke work-ups that are unnecessary, and probably missing the chance to save tens of thousands of lives because we aren't properly diagnosing their dizziness or vertigo as stroke symptoms," he said in a statement.
Newman-Toker led a team of physicians from Johns Hopkins University, the University of Illinois and the University of Michigan, who published the results of a very small, preliminary study of the laptop device's performance Tuesday in the journal Stroke.
According to background information in the report, Americans make 2.6 million ER visits every year for vertigo and dizziness, about 4% of which turn out to be attributable to a stroke. But figuring out when a stroke is taking place in the emergency room can be tricky, because many nonspecialists aren't trained to recognize certain telltale patterns of eye movements that can be used as predictors of stroke.
The stroke-detecting device uses a set of goggles incorporating a webcam and an accelerometer in the frame, hooked up to a laptop running software that can interpret data relating to three types of relevant eye movements.
To investigate if the machine could recognize strokes accurately, Newman-Toker's team used it to examine 12 patients who came to the emergency rooms at the Johns Hopkins Hospital in Baltimore and the University of Illinois College of Medicine at Peoria. The subjects, 10 men and two women with an average age of 62, had symptoms of a "high-risk-for-stroke clinical presentation" known as acute vestibular syndrome. The patients had new, persistent dizziness; the darting eye movements known as nystagmus; and nausea and vomiting, head motion intolerance, or new troubles walking.
According to the machines, six of the patients had suffered a stroke and six had not. Subsequent magnetic resonance imaging scans confirmed that the machine got it right, across the board.
"Using this device can directly predict who has had a stroke and who has not," Newman-Toker said.
But it will take more testing, involving larger numbers of patients in randomized trials, to know if the device can live up to its potential, the team wrote in their report.
The machines, which are not currently approved for use in the U.S., were lent to researchers by manufacturer GN Otometrics. The company does not have a financial interest or any other involvement in the study, according to Newman-Toker.
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