Transcript for Silent Strokes: The Cause of Lost Memory?
Something that's happening far more frequently than any of us thought silent strokes and they could explain that increasing memory loss over the years. We learned today that eleven million Americans a year suffer from these hidden strokes and tonight what you can do here's ABC's -- Davis. Here called silent strokes because there are no symptoms. A regular stroke kills a large section of the brain in an instant knocking out language or causing paralysis. Silent strokes do their damage a little bit at a time. Just -- silent stroke has little or no effect but over time the damage builds. The new research found -- strokes can start after age thirty. 713. Of the population is having a silent stroke each year. The researchers studied about 700 elderly people without dementia. Brain scans revealed nearly a fourth of them had damage to the brain left by these silent strokes those who had these spots did worse on memory tests. It's becoming more and more apparent that these strokes not only affect us physically but also mentally researchers say now -- know to look for spots like these in the brain. They can use these MRI scans to help identify people who've had a silent stroke. -- possibly gives us a target for earlier intervention on people to be able to identify them and institute interventions. The good news silent strokes are preventable if we -- risk factors like obesity high blood pressure smoking and diabetes so with good choices. We can preserve the memories. Lindsey Davis ABC news New York.
This transcript has been automatically generated and may not be 100% accurate.