WEDNESDAY, June 30 (HealthDay News) -- In individuals with mild cognitive impairment, fluorodeoxyglucose-positron emission tomography (FDG-PET) and episodic memory may be the best predictors of conversion to Alzheimer's disease, while cerebrospinal fluid (CSF) proteins and -- to a lesser extent -- FDG-PET predict longitudinal cognitive decline, according to a study published online June 30 in Neurology.
Susan M. Landau, Ph.D., of the University of California in Berkeley, and colleagues performed brain scans, administered episodic memory tests, and assessed the apolipoprotein E gene and CSF proteins in 85 subjects, aged 55 to 90 years, with amnestic mild cognitive impairment. The cohort was watched for a mean 1.9 years for the development of Alzheimer's disease, and associations with the potential predictors were assessed.
During the follow-up, the researchers found that 28 subjects developed Alzheimer's disease, with those who had abnormal results on both the FDG-PET scan and memory test 11.7 times more likely to develop the condition than subjects who tested normal. In univariate analysis, the ratio of hyperphosphorylated tau proteins in CSF predicted cognitive decline, as did FDG-PET to a lesser degree.
"Our results suggest that these biomarkers could be effective in identifying patients with mild cognitive impairment who are more likely to progress to Alzheimer's disease over relatively brief time periods. This approach could be useful for identifying patients who would benefit from treatment when it becomes available and for selecting subjects in clinical trials of therapeutic agents for mild cognitive impairment," the authors write.