'Silent Strokes' May Damage Memory About 25% of seniors have had them By Dustin Lushing, Newser Staff Posted Dec 30, 2011 5:00 PM CST 14 comments Comments Silent strokes may be damaging the memory of seniors. (Shutterstock) (Newser) – "Silent strokes" may be taking a toll on seniors' memory. A new study shows that seniors who have suffered such strokes—they don't have obvious symptoms but leave behind dead brain cells—do worse on memory tests, reports USA Today. It's no small thing: An estimated 1 in 4 seniors have had the strokes. "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," says the author of the study in the upcoming issue of Neurology.