Poster A84, Saturday, March 24, 1:30–3:30 pm, Exhibit Hall C
Organized patterns of cortical thinning observed across the healthy adult lifespan.
Phillip Agres1, Micaela Chan1, Liang Han1, Neil Savalia1, Gagan Wig1,2; 1Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, 75235, USA, 2Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
Healthy aging is associated with cortical gray matter thinning, however in a non-uniform manner. Evidence for similarities and differences in rates of thinning across cortical regions have been made at the level of cortical lobes and gyral & sulcal landmarks. This approach has led to observations of thinning distinctions between regions involved in associative versus sensory/motor processing. Given this functional distinction, it is possible that patterns of cortical thinning exhibit more specific processing-related distinctions of the brain. To test this hypothesis, we examined regional covariance of thinning patterns across participants sampled from the healthy adult lifespan (N=248; 20-89yrs). Cortical thickness change data were calculated across two time-points spanning approximately 3.5 years (i.e., longitudinally). Brain regions and their associated functional systems were pre-defined from resting state functional correlations (rsFC). Greater cortical thinning similarity was observed between nodes (regions) within the same functional system than with nodes of other systems, controlling for effects of age and baseline cortical thickness. To understand more deeply the systematic relationships of regional thinning similarity, sub-groups comprised of regions exhibiting highly similar thinning patterns across participants were identified using a community detection algorithm. Nodes were clustered into communities overlapping with their rsFC functional systems at a local level, but segments of large spatially distributed systems, such as the default network, were split across multiple communities at sparse thresholds. These results indicate that cortical regions within rsFC-defined systems exhibit similar thinning patterns across the lifespan, and that structural covariance of cortical thinning may delineate local cortical distinctions.
Topic Area: NEUROANATOMY