By Jeannine Stein, Los Angeles Times
LOS ANGELES — Silent strokes, small areas of dead brain tissue, may be responsible for memory loss in older people.
A study, released recently in the journal Neurology, looked at the effects of those silent strokes on memory, as well as hippocampus size. A smaller hippocampus has been linked in some prior studies with memory loss.
Participants included 658 people age 65 and older who had no signs of dementia. They took neuropsychological tests that measured language, information processing speed, memory and visual perception. They were also given MRIs and their hippocampal volume was measured.
Among the study subjects, 174 had silent strokes, so called because they can sometimes go unnoticed, although they can damage the brain. Those strokes were linked with having a smaller hippocampus. But researchers also discovered that the strokes by themselves were associated with doing more poorly on memory tests compared with those who didn’t have evidence of silent strokes.
The study authors wrote that brain infarctions are “a largely preventable brain injury with clearly identified risk factors, and prevention programs.”
Study co-author Adam M. Brickman of Columbia University Medical Center in New York said in a news release: “Given that conditions like Alzheimer’s disease are defined mainly by memory problems, our results may lead to further insight into what causes symptoms and the development of new interventions for prevention. Since silent strokes and the volume of the hippocampus appeared to be associated with memory loss separately in our study, our results also support stroke prevention as a means for staving off memory problems.”