Neural correlates of domain-specific cognitive decline: the ARIC-NCS study

Objective: To evaluate the association of cognitive declines in the domains of memory, language, and executive function with brain gray matter (GM) volume in old age.
Methods: Prospective study of 1,846 participants in the Atherosclerosis Risk in Communities (ARIC) study who underwent 3T brain MRI scans in 2011-2013. Participants were categorized by cognitive domain performance trajectory over the prior 20 years (cut-point to define decline: 20th percentile). Associations between GM volume and cognitive declines were assessed at the voxel level using voxel-based morphometry and at the regional level using atlas-defined GM volumes of specific regions of interest.
Results: Participants were an average age of 76 years, 60% were female, and 28% were black. Participants in the top 20th percentile for decline in the memory domain had smaller GM volumes in the medial temporal lobe (-3.3%, 95% CI: -4.6% to -2.1%), amygdala (-2.7%, 95% CI: -4.1% to -1.3%), entorhinal cortex (-4.1%, 95% CI: -6....