The brains of Alzheimer's disease patients may also begin to shrink up to 10 years before the disease is diagnosed, finds a new study in Neurology.
The finding, made with MRI brain scans, suggests that looking for brain shrinkage could become an effective way to detect the earliest signs of the disease. And that might one day help in the development of better treatments for Alzheimer's.
"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.
For the study, researchers used MRI (magnetic resonance imaging) scans to measure specific areas of the cerebral cortex known to be involved in Alzheimer's.
They studied two groups of people in their 70s with no memory issues or signs of Alzheimer's disease: one group of 33 people were followed for about 11 years, while another group was followed for seven years.
In the first group, eight went on to develop Alzheimer's; in the other group, seven developed the brain disease.
Those who had thinning of the cerebral cortex and therefore a smaller brain size in the key areas associated with Alzheimer's were three times more likely to develop dementia over the following 10 years than those with higher measurements, the study found.
Study researcher Dr. Bradford Dickerson, a neurologist at Harvard Medical School in Boston, said in a news release; "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."
There is currently no single test that can diagnose Alzheimer's, which is usually identified by examining symptoms and disease course.
Eli Lilly and Co, General Electric and other companies are developing special imaging agents for use in MRI that can detect proteins in the brain that signal the presence of Alzheimer's disease-related proteins. The tests are being developed to rule out Alzheimer's in patients who already have symptoms of the disease.
