Brain starts shrinking in Alzheimer’s disease a decade earlier: Study

By Dr. Ananya Mandal, MDApr 13 2011

According to American researchers, brain scans of healthy people showed signs that the brain was shrinking in Alzheimer's-affected areas nearly a decade before the disease was diagnosed. This comes in the latest issue of the journal Neurology and it may offer a new way to detect the disease early, an advance that could help in the development of effective treatments for Alzheimer's, a brain-wasting disease that affects up to 26 million people globally.

Leyla deToledo-Morrell of Rush University Medical Center in Chicago, one of the researchers said, “The magnetic resonance measurements could be very important indicators to help identify who may be at risk of developing Alzheimer's dementia… If a drug therapy or treatment is developed in the future, those who are still without symptoms but at great risk would benefit the most from treatment.”

For the study the team involved two groups of healthy people in their 70s who had brain scans at Rush University in Chicago and at Massachusetts General Hospital/Harvard Medical School in Boston and were followed for an average of nine years. During the study, 50 participants remained cognitively normal and 15 developed Alzheimer's disease. At the end of the study, people who had the highest amount of shrinkage in specific areas of the cerebral cortex were three times more likely to develop the disease.

Researchers in the study used magnetic resonance imaging or MRI, equipment that is already in wide use in most hospitals. Eli Lilly and Co, General Electric and other companies are developing special imaging agents that can detect proteins in the brain that signal the presence of Alzheimer's disease-related proteins.

Dr. Brad Dickerson of Massachusetts General, who led the study explained, “We also found that those who express this MRI marker of the Alzheimer's disease in the brain were three times more likely to develop dementia over the following 10 years than those with higher measurements…These are preliminary results that are not ready to be applied outside of research studies right now, but we are optimistic that this marker will be useful in the future.”

Rebecca Wood, chief executive of Alzheimer’s Research UK charity, said, “This adds to growing evidence that the changes associated with Alzheimer’s disease begin long before symptoms start to appear…However, this is a small study and it needs to be expanded before we can be certain of the method’s accuracy in predicting Alzheimer’s. The ability to detect Alzheimer’s in its earliest stages is crucial if we are to test new treatments with the groups of people who stand to benefit most.”