( ll Dr. Petrella said. The test req...)Memory loss affects more of the brain than previously thought

The test required 40 patients to recall names of familiar faces and to learn and recall unfamiliar face-name associations. All patients showed brain activation in several brain regions during the task, but, compared with the controls, the patients with MCI showed a lower level of activation in the prefrontal cortex (during formation and retrieval), left hippocampus (during retrieval) and left cerebellum (during formation) and an increased level of activation in the posterior frontal lobes (during retrieval).

"These findings suggest that we should be paying closer attention to frontal lobe function in detecting people at risk for AD and may also point to new preventive strategies," said co-principal investigator P. Murali Doraiswamy, M.D., chief of the Division of Biological Psychiatry in the Department of Psychiatry at Duke.

Both researchers caution that their findings are preliminary. They are in the process of completing a larger study to confirm these results and to examine their value as a diagnostic or predictive test. There have also been a number of previous fMRI studies in people with MCI, and researchers are working to put these findings together to develop a synergistic combination of memory testing, genetic and imaging studies that together can best predict early onset and monitor progression of AD.

"If memory problems are beginning to impact the day-to-day life of you and your family, you should undergo comprehensive testing by a physician, as memory loss can be caused by many underlying factors such as depression, thyroid problems and stress, and doesn't necessarily indicate early AD," Dr. Petrella said.