Researchers, using whole-brain event-related functional MRI (fMRI), have determined that a low-effort, high-accuracy memory activation task is sensitive to Alzheimer's disease (AD) risk factors, such as family history and apolipoprotein E (APOE) e4.
M. Seidenberg, PhD, from the department of psychology at Rosalind Franklin University of Medicine and Science in Chicago, and colleagues, reported their findings in the August issue of Neurology. They divided 69 cognitively asymptomatic adults into three groups based on their Alzheimer risk—no family history, no APOE e4 allele; family history, no APOE e4 allele; and family history and APOE e4 allele. The memory task involved discriminating between familiar and unfamiliar names.
The subjects with AD risk factors exhibited greater memory activation in recognizing famous names relative to unfamiliar names compared with the group without risk factors, particularly in the bilateral posterior cingulate/precuneus, bilateral temporoparietal junction, and bilateral prefrontal cortex. The increased activation was more apparent in the group with a family history and APOE e4 than in the group with just the family history.
The group without risk factors demonstrated greater activation for unfamiliar than familiar names, predominantly in the supplementary motor area, bilateral precentral, left inferior frontal, right insula, precuneus and angular gyrus.
The researchers said their results could not be attributed to demographic variables, cerebral atrophy, episodic memory performance, global cognitive functioning, activities of daily living or depression.