PMC

CSF biomarkers of AD and structural covariance of the default network scores.

Whole-brain axial slices of the structural covariance of the default network. A, Healthy young, middle-aged, and older adults (with and without mild dementia) from Study 1, OASIS. B, Healthy adults, mild cognitive impairment, and Alzheimer's disease patients from Study 2, ADNI. For thresholding information, see and Materials and Methods.

Structural covariance of the default network in healthy adults. Across healthy OASIS participants, the integrity of posterior cingulate cortex covaries with medial prefrontal cortex, lateral temporal cortex, angular gyrus, and other regions. Results are thresholded to the top 5% reliable voxels, all exceeding p < 0.001. PLS is performed in a single analytic step; thus, no correction for multiple comparisons is required (see Materials and Methods).

Whole-brain structural covariance of the default network. Row 1 represents healthy and dementia participants from the OASIS dataset; Row 2, the ADNI. In both samples, declines are observed in the structural covariance of the default network scores with age. C, Decline across the lifespan: black represents healthy participants; red represents mild dementia. F, Longitudinal decline in healthy and pathological aging (where declines are steepest); mean ± SE for each diagnostic group at three time points. HC, Healthy older adult control; AD, probable Alzheimer's disease; MCInc, mild cognitive impairment, nonconverters to AD; MCIc, mild cognitive impairment, converters to AD; scDN score, composite score for the structural covariance of the default network, reflecting the degree to which the covariance pattern (A, B, D, E) was manifest in each participant's structural brain image (see Materials and Methods). For thresholding information, see and Materials and Methods.