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, U.S. researchers said on Wednesday.
The finding, published in the journal Neurology, 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.
"The magnetic resonance measurements could be very important indicators to help identify who may be at risk of developing Alzheimer's dementia," Leyla deToledo-Morrell of Rush University Medical Center in Chicago, who worked on the study, said in a statement.
"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," deToledo-Morrell said.
The study 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.
"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," Dr. Brad Dickerson of Massachusetts General, who led the study, said in a statement.
"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," he said.
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.
But these tests currently are being developed to rule out Alzheimer's in patients who already have symptoms of the disease.