When memory loss doesn t mean Alzheimer s disease

Although memory impairment is one of the defining traits of Alzheimer s disease, a study just published in Neurology suggests that memory loss among older adults may have other possible etiologies. Researchers at Columbia University Medical Center have found that subclinical strokes often called silent strokes due to their tendency to go undetected are often associated with memory impairment in the elderly.

By administering MRI brain scans to 658 men and women aged 65 and older, none of whom had a history of dementia, the researchers were able to identify those who had experienced a silent stroke. In 174 of these participants, small pockets of dead brain cells appeared on the MRI scans, signaling a previous silent stroke. These individuals did not perform as well as the other study participants on tests of memory, language skills, thinking speed, and visual perception.

These new findings are important, say the study authors, since memory impairment in older adults is typically attributed to the shrinkage of the hippocampus that occurs when an individual develops Alzheimer s disease. In the patients in the current study, however, the memory impairment is likely a result of a different kind of brain damage, resulting from a silent stroke. Given that the small pockets of dead brain cells indicative of a silent stroke are found in about a quarter of adults over 65 years old, the study authors believe that their findings may lead to further insight into what causes symptoms and the development of new interventions for prevention.