Stroke or dizziness? Bedside test can tell
A bedside device that measures eye movements could become a standard way of determining if extreme dizziness is being caused by a stroke, researchers say.
Johns Hopkins School of Medicine researchers performed a study on 12 people using a portable video-oculography machine, which was 100% accurate in determining whether dizziness was being caused by a stroke. If larger studies confirm these results, the machine could be used in the same way electrocardiograms are used to diagnose heart attacks, said study leader David Newman-Toker, M.D., Ph.D.
The machine consists of goggles connected to a webcam, laptop and accelerometer. It mimics a horizontal head impulse test, which is a very accurate way to determine if dizziness is linked to a stroke. However, this test requires a clinician with expert judgment of a patient's eye movements. The video-oculography machine eliminates the need for this high level of human expertise. It could be “easily employed” to prevent as many as 100,000 stroke misdiagnoses annually, Newman-Toker said.
“Using this device can directly predict who has had a stroke and who has not,” he added. “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.”
Newman-Toker says that the device can potentially be used more widely than a horizontal head impulse test, leading to earlier stroke diagnosis and more efficient triage and treatment decisions for patients with disabling dizziness. Overlooked strokes mean delayed or missed treatments that lead to roughly 20,000 to 30,000 preventable deaths or disabilities a year, he said. The technology, he added, could someday be used in a smartphone application to enable wider access to a quick and accurate diagnosis of strokes whose main symptom is dizziness, as opposed to one-sided weakness or garbled speech.