Now new research from Adam M. Brickman, PhD, of the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center in New York, shows that silent strokes may be the cause. Essentially small dead spots in the brain are found in one out of four elderly people.
Brickman's study is published in the January 3rd issue of Neurology®, the medical journal of the American Academy of Neurology and he states :
"The new aspect of this study of memory loss in the elderly is that it examines silent strokes and hippocampal shrinkage simultaneously."
His study was conducted with over 650 people aged 65 and older. They were free from dementia and were given MRI brain scans. They also took tests to measure their memory, language, speed at processing information and visual perception. Of the 658 people, 174 were identified as having had silent strokes.
Those 174 scored worse on memory tests, regardless of how large their hippocampus was.
Brickman says that :
"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."
It's not known exactly why or how Alzheimer's destroys the brain's memory, but research has started to show accumulations of proteins called called amyloid plaques, among brain cells. Larger tangled protein strands then start to appear inside the cells. However, treatments to remove the proteins have not been particularly successful in improving memory loss.
Brickman's research points the investigation in a new direction, and focuses more on the vascular system. While circulation and loss of brain function from minute strokes may not be the whole solution its certainly an important part of it, as Brickman concludes :
"What our study suggests is, even when we account for the decline in memory attributed to hippocampal shrinkage or degeneration, that strokes ... play an additional role in the memory decline," Brickman says. He is the Herbert Irving assistant professor of neuropsychology at Columbia University College of Physicians and Surgeons.
Written by Rupert Shepherd