Seemingly Healthy People Have Had Strokes

(June 29< 2008) - As many as ten percent of the population may have had strokes (Read about "Stroke") and not even known it. A recent study found that about 10 percent of the apparently healthy middle-aged participants with no symptoms of stroke were injured from "silent strokes," researchers report in Stroke: Journal of the American Heart Association.

Silent cerebral infarction (SCI), or "silent stroke," is a brain injury likely caused by a blood clot interrupting blood flow in the brain. It's a risk factor for future strokes and a sign of progressive brain (Read about "The Brain") damage that may result in long-term dementia. (Read about "Dementia")

"The findings reinforce the need for early detection and treatment of cardiovascular risk factors in midlife," said Sudha Seshadri, M.D., co-author of the study. "This is especially true since SCIs have been associated with an increased risk of incident stroke and cognitive impairment."

Researchers evaluated magnetic resonance imaging (MRI) from about 2,000 people, average age 62. (Read about "MRI - Magnetic Resonance Imaging") Among patients who displayed no symptoms of stroke, 10.7 percent had SCIs on routine brain MRI, researchers said. Previous estimates of SCIs ranged from 5.8 percent to 17.7 percent depending on age, ethnicity and other issues. Of those in the study with SCIs, 84 percent had a single lesion.