Brain Size Linked to Mental Decline Caused by Alzheimer's Disease
04/15/08 Portland, Ore.
Research presented this week at the American Academy of Neurology meeting in Chicago
Researchers at Oregon Health & Science University have discovered a correlation between a person's brain volume and the occurrence of mental decline caused by Alzheimer's disease. The research was presented today at the American Academy of Neurology meeting in Chicago.
Researchers at the OHSU Layton Aging & Alzheimer's Disease Center found that the volume of the entire brain, and specifically the region called the hippocampus, tended to be larger in deceased elderly persons who did not suffer from cognitive impairment. However, autopsies revealed that these same people had large clusters of proteins associated with Alzheimer's disease.
"When we examined the brains of healthy study subjects, we found the same kinds of changes usually seen in Alzheimer's disease patients - clusters of proteins called amyloid plaques and tangles," explained Deniz Erten-Lyons M.D., an assistant professor of neurology in the OHSU School of Medicine and a staff neurologist at the Portland Veterans Affairs Medical Center. "However, prior to death, these people did not suffer from mental decline. We also noted that these healthy study subjects had brain volumes that were on average, larger than the brain volumes of the Alzheimer's subjects we studied."
Jeffrey Kaye, M.D., director of the Layton Aging & Alzheimer's Disease Center and a professor of neurology in the OHSU School of Medicine was the senior scientist involved in the research.
To conduct their study, Kaye, Erten-Lyons and their colleagues observed the brains of 36 deceased persons: 12 healthy subjects and 24 Alzheimer's sufferers. Through the use of MRI imaging, the scientists were able to note distinct differences in brain volume when they compared the two groups. Specifically, the brain volumes of healthy subjects were approximately 10 percent larger when compared to Alzheimer's sufferers.
"We are hopeful that this research will help us further understand the structural and genetic ties to Alzheimer's disease and perhaps offer clues that may help us develop new drugs or therapies," explained Kaye. "We should caution that at this point we do not believe brain volume is an accurate tool for diagnosing the disease. However, in the future, this correlation could be helpful to doctors and researchers alike."
Funding for this research was provided by the U. S. Department of Veterans Affairs Veterans Health Administration and the National Institute on Aging, a component of the National Institutes of Health.
Oregon Health & Science University is the state's only health and research university, and Oregon's only academic health center. OHSU is Portland's largest employer and the fourth largest in Oregon (excluding government), with 12,400 employees. OHSU's size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves patients from every corner of the state, and is a conduit for learning for more than 3,400 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to every county in the state.