June 26, 2008 -- It's possible to have a stroke and not realize it immediately. So it's wise to know the signs. But what if a stroke occurred and you didn't even notice?
A new study found that nearly 11% of people who thought they were healthy actually had some brain damage from a "silent" stroke. Silent strokes are true strokes but don't result in any noticeable symptoms. People who have had a silent stroke are at higher risk for subsequent strokes and for an accelerated loss of mental skills.
Researchers, led by Rohit Das, MD, from Boston University's School of Medicine, reviewed MRI (magnetic resonance imaging) scans from 2,040 people participating in the Framingham Study, an ongoing study examining the relationship between risk factors and subsequent cardiovascular events. The MRI scans were reviewed for evidence of stroke. The average age of the participants was 62; most were of European ancestry. None of the participants had a history of stroke or stroke-type symptoms.
The study also examined whether people who had silent strokes had more concentrated levels of cholesterol in their blood and more extensive thickening in the carotid arteries, the main arteries that supply the head and neck with blood.
Here are the main results from routine MRI scans:
Nearly 11% of participants who showed no overt sign of stroke had suffered some brain damage from a silent stroke.