Quick eye test can indicate possible stroke
Clinicians may soon have a simple method for diagnosing stroke in patients complaining of dizziness, nausea, and spinning sensations. Stroke researchers are testing a one-minute eye movement exam that involves three maneuvers: moving the patient's head rapidly from side to side to detect an inability to keep the eyes stable; looking for jerking eye movements when the patient's eyes follow the clinician's finger as it moves right and left; and checking the patient's eye position to see if one eye is higher than the other. (Stroke. 2009;40:3504-3510).
In a recent small “proof of principle” study, 69 of 69 strokes were correctly diagnosed using the HINTS (Head-Impulse/Nystagmus/Test-of-Skew) method in patients with acute vestibular syndrome (characterized by vertigo, nausea/vomiting, head-motion intolerance, nystagmus, and unsteady gait). All the study subjects had felt severe dizziness for several continuous hours and had at least one risk factor for stroke.
MRI scans fared less well than the HINTS test, with initial scans indicating eight false-negative stroke findings. Follow-up MRIs rendered the correct diagnosis for these patients. In a statement describing the findings, neurologist and lead investigator David E. Newman-Toker, MD, of Johns Hopkins Medicine in Baltimore says, “The idea that a bedside exam could outperform a modern neuroimaging test such as MRI is something that most people had given up for dead, but we've shown it is possible.”
Previous research had shown that people experiencing a stroke have eye-movement alterations that correlate with stroke damage to various areas of the brain—alterations that are distinct from those caused by benign ear problems. In addition to successfully identifying stroke, the eye-movement test helped the researchers correctly diagnose 24 of 25 patients with inner-ear conditions.