CHAPEL HILL, N.C., Sept. 25 -- A sensitive sign of the early stages of Alzheimer's disease may be dampening of activity in the posteromedial cortices during a memory task, as seen by functional MRI, investigators here suggested.
In a study comparing functional MRI scans of healthy volunteers with those of patients with mild cognitive impairment or mild Alzheimer's disease, the degree of activation of the posteromedial cortices correlated significantly with scores on a verbal learning test, reported Jeffrey R. Petrella, M.D., of Duke, and colleagues.
Deactivation of the posteromedial cortices during novel or familiar facial encoding tasks could be a more sensitive marker for early-stage Alzheimer's than activation of other areas, the authors wrote in the October issue of Radiology.
"The findings of this study implicate a potential functional, rather than structural, brain marker -- separate from atrophy -- that may help enhance diagnosis and treatment monitoring of Alzheimer's patients," Dr. Petrella said.
