Cognitive reserve and Alzheimer's disease biomarkers are independent determinants of cognition

Behavior item. In a followup analysis, we examined correlations between Agitation factor score and metabolism in the three cortical volumes identified in the SPM analysis. Agitation factor score was inversely correlated with metabolic activity in each (rs 1⁄4 0.35 0.36; p < .001), indicating that symptom severity is associated with the extent of hypometabolism. Conclusions: Dysfunction in right temporal/midfrontal and bilateral cingulate cortex contributes to angry, irritable, and hostile behavior in AD, but impulsive, disinhibited, and repetitive motor behaviors may not localize to discrete cortical circuits in AD. Distinct biomarkers for specific “agitated” behaviors can reveal intermediate phenotypes that can improve understanding of behavioral phenomenology and promote optimal interventions in AD.