Cognitive decline predicted by brain scans

Among normal, health elderly people, brain imaging can spot changes that suggest an impending decline in cognitive function, California-based researchers report.

This is important, lead investigator Dr. William Jagust told Reuters Health, because effective treatments for Alzheimer's disease might be developed in the relatively near future.

"If such treatments are to be effective," he pointed out, "we will have to apply them to individuals in the earliest possible stage of the disease - preferably even before symptoms are present - in order to have maximal benefit, since once symptoms appear the brain has already suffered considerable damage."

Jagust, at the University of California, Berkeley, and colleagues performed brain scans in 60 cognitively normal men and women with an average age of 69.5 years. The subjects were participants in the Sacramento Area Latino Study on Aging (SALSA) and most were Mexican-American.

They were followed for almost 4 years, and about once a year underwent testing to assess global cognition and memory.

Six of the subjects developed dementia or cognitive impairment, according to the team's report published in the Annals of Neurology. Examination of scans showed that areas of lower glucose metabolism in upper and side regions of the brain were strongly linked to a faster decline in mental performance.

The anatomical location of the findings, the researchers conclude, "suggests detection of preclinical Alzheimer's disease pathology."

When and if treatments for Alzheimer's disease become available, Jagust added, "studies like ours, which aim to detect signs of the disease in normal older people, could have clinical applications."

SOURCE: Annals of Neurology, February 8, 2006.