Because researchers believe that Alzheimer's disease starts changing the brain years before any symptoms appear, the disease may be most amenable to treatment in these pre-clinical stages. If so, detecting the early changes will be crucial for future therapies.
People who carry the genetic risk factor, the 4 allele of the Apolipoprotein (APOE) gene, have higher risk of developing the disease than non-carriers and usually show symptoms earlier.
"It is possible that what we're seeing in the APOE- 4 carriers are early changes in the brain caused by Alzheimer's disease," says the study's senior author, Yaakov Stern, Ph.D., of CUMC's Taub Institute and Sergievsky Center.
But he and the study's first author, Nikolaos Scarmeas, M.D., caution that more research is needed before it's known for certain if the difference is an early sign of Alzheimer's. "It's also possible that the brain differences we see are related to the APOE gene but are not necessarily directly related to incipient Alzheimer's," says Dr. Scarmeas, a neurologist in the Taub Institute, Sergievsky Center and neurology department. "Even so, the differences we've found may provide information on how the 4 allele predisposes carriers to Alzheimer's disease."
The present study appears in the Nov.-Dec. 2004 issue of the American Journal of Geriatric Psychiatry.
About the Study
The researchers looked at six people who carried the APOE- 4 risk factor and 26 non-carriers.
None of the 32 participants, mostly in their 60s and 70s, had any signs of dementia or memory deficits and the two groups could not be distinguished from one another by standard cognitive tests.