Diagnosing Alzheimer's in the Living

A new imaging agent that homes in on the gummy plaques and tangles that jam up the brains of Alzheimer patients has allowed doctors to see the disease in a living person for the first time, researchers said Wednesday. The mind-robbing disease, which is always fatal and has no cure, can now only be definitively diagnosed by looking at the brain after a patient has died.
IN THE NEW study, the researchers were able to view the messy clumps of dead cells in the brains of nine living Alzheimer's patients. The finding means that Alzheimer's, which affects 4 million Americans and millions more around the world, may be diagnosed in the early stages, when treatments might be able to do some good, said Jorge Barrio of the University of California Los Angeles.
The method might also be useful in testing whether treatments for Alzheimer's are working, Barrio said.
But the Alzheimer's Association cautioned that while interesting, the study is too small to draw firm conclusions or change medical practice.
The researchers are specialists in nuclear medicine, which uses radioactive compounds to help make images of the body. They designed and built a molecule called FDDNP.
To his surprise, Barrio found that FDDNP had a specific affinity for the neurofibrillary tangles and beta-amyloid plaques found in the brains of Alzheimer's patients.
They tested the compound first in laboratory dishes, then in animals. Writing in the American Journal of Geriatric Psychiatry, they said they finally tested it in nine Alzheimer's patients and seven healthy volunteers.
After injecting FDDNP, they used positron emission tomography (PET) scans, which can show how tissue is acting by measuring its use of sugar for basic energy.
The scans clearly showed lesions in the areas of the brain associated with Alzheimer's.
Then one of the patients died, and Barrio's team was able to examine the brain. Indeed, the patient had damage in the areas suggested by the scan, and clearly had Alzheimer's.
"This is a huge step forward in getting a jump on the disease before it progresses to cause brain impairment," Dr. Stephen Bartels, president of the American Association for Geriatric Psychiatry, said in a statement.
Barrio said his team planned to apply to the U.S. Food and Drug Administration for a license to use the method to check at-risk people for Alzheimer's.
By the time symptoms of Alzheimer's show up - memory loss, confusion and other problems - a patient already has considerable brain damage, Barrio said.
But studies show the disease starts years before, and progresses without showing symptoms . Studies have also shown that people who take aspirin-related drugs regularly have a lower risk of Alzheimer's.