Researchers Development Potential Test to Predict Alzheimer's

Researchers using high-tech imaging and memory tests say they have developed the most accurate indicator yet of whether a person will develop Alzheimer's disease, a fatal and incurable brain-wasting illness that slowly robs its victims of their memory. VOA's Jessica Berman in Washington reports.

One of the most difficult problems in the field of Alzheimer's research, say experts, is the ability to accurately predict early on who will develop Alzheimer's, a neurodegenerative brain disease that can take decades to progress. The disorder usually begins in older adults with mild forgetfulness -- a symptom that can also be a function of normal aging.

But researchers at the University of California Berkeley, using an established imaging technology called Positron Emission Tomography, or PET, and a common memory test, found that participants who received a low score on the memory test and a PET image that showed activation in certain brain regions were 12 times more likely to develop Alzheimer's.

The two-year study, conducted by Susan Landau and her colleagues, involved 85 patients who were suspected of having Alzheimer's. Twenty-eight of them went on to develop the disease.

Michael Weiner, a professor of Medicine, Radiology, Psychiatry and Neurology at the University of California in San Francisco, says PET imaging, which looks for metabolic irregularities in the brain associated with Alzheimer's, is a potentially powerful diagnostic tool. "And Dr. Landau and her colleagues have done a very nice study which shows the predictive value of these techniques. So it's another step forward in the ability to detect Alzheimer's disease at an early stage prior to the development of dementia," he said.

There is no cure for Alzheimer's, and drugs only treat some of the symptoms of the disease, such as forgetfulness.

The concern among some researchers and physicians is that these drugs can also be used in people who are forgetful but do not have Alzheimer's. So Dr. Weiner, who also heads the Center for Imaging of Neurodegenerative Diseases for the U.S. Department of Veterans Affairs, says improved diagnostics with technologies such as PET will help ensure that medications are used correctly.

"But the long-term advantage is that at some point, we will have medications or treatments which truly slow the progression of Alzheimer's disease or even prevent symptoms in Alzheimer's disease. And when that happens, then it's going to be very important to have techniques which provide an early diagnosis," he said.

Critics of using high-tech imaging to help diagnose Alzheimer's say it is expensive and not a practical standard of care for most people suspected of having the disease.

But Michael Weiner disagrees, saying that PET scanners are common and are used for cancer, so using PET to help diagnose Alzheimer's only employs existing technology.

An article detailing the use of Positron Emission Tomography and memory tests in the early diagnosis of Alzheimer's disease is published in the journal Neurology.