A bedside electronic device that measures eye movements can be used to quickly determine whether the cause of severe, continuous, disabling dizziness is a stroke or something benign, according to researchers at Johns Hopkins Medicine, Baltimore, MD.
To distinguish stroke from a more benign condition, such as vertigo linked to an inner ear disturbance, specialists typically use three eye movement tests that are essentially a stress test for the balance system. In the hands of specialists, these clinical tests have been shown in several large research studies to be extremely accurate but require expertise to determine if a patient is making the fast corrective eye adjustments needed.
For the new study, researchers instead performed the same tests using a small, portable video-oculography device, which detects minute eye movements that are difficult for most physicians to notice. The machine includes a set of goggles with a USB-connected webcam and an accelerometer in the frame. The webcam is hooked up to a laptop where a continuous picture of the eye is taken. Software interprets eye position based on movements and views of the pupil, while the accelerometer measures the speed of the movement of the head.
They say the test could be easily employed to prevent misdiagnosis of as many as 100,000 strokes a year, leading to earlier stroke diagnosis, and more efficient triage and treatment decisions for patients with disabling dizziness.
The device was developed overseas and is used in balance clinics there, but is not yet approved for use in the United States.
