So-called silent strokes may be responsible for decreased hippocampus size, and thus overall memory loss, research suggests. According to the Los Angeles Times, a new study published in the journal Neurology found that study subjects who had silent strokes performed more poorly on memory tests than those who had no evidence of such episodes.
Silent strokes occur when a small area of brain tissue dies and symptoms go unnoticed by the victim. According to the study authors, such brain infarctions are “a largely preventable brain injury with clearly identified risk factors, and prevention programs.” However, they are fairly common—ABC reports that about a quarter of older adults have experienced a silent stroke.
And that could lead to brain damage and long-term memory loss, the study suggests.
To reach their conclusions, Adam Brickman and his team at Columbia University observed 658 adults with an average age of 79 who had no history of dementia. They were tested for memory skills, language skills and thinking abilities. They were also given an MRI brain scan to measure the size of their hippocampus, the part of the brain that regulates memory and emotion.
Of these participants, 174 had experienced a silent stroke. They did not perform as well on memory tests and MRI scans showed that poor performance was independent of hippocampus size. Brickman noted that while most memory loss is related to changes in the size of the hippocampus, silent strokes seem to affect its victims independent of brain changes.
