Age‐related decrements in cortical gyrification: Evidence from an accelerated longitudinal dataset

Abstract

Cortical gyrification has been found to decrease due to aging, but thus far this has only been examined in cross‐sectional samples. Interestingly, the topography of these age‐related differences in gyrification follows a distinct gradient along the cortex relative to age effects on cortical thickness, likely suggesting a different underlying neurobiological mechanism. Here I examined several aspects of gyrification in an accelerated longitudinal dataset of 280 healthy adults aged 45–92 with an interval between first and last MRI sessions of up to 10 years (total of 815 MRI sessions). Results suggest that age changes in sulcal morphology underlie these changes in gyrification.

Novel Volumetric and Surface-Based Magnetic Resonance Indices of the Aging Brain – Does Male and Female Brain Age in the Same Way?

“…Several studies have revealed that age-related decreases in GI show different topography than changes in CT and are more related to the parameter of SD ( 14 – 16 ). Furthermore, SD, GI, and FD have been reported to show positive associations with cognitive function ( 15 , 47 , 48 ). To our knowledge, there are no other reports on the age–sex-related patterns of changes in these parameters across the lifespan.…”

“…In healthy adults, age-related thinning is observed across the majority of the cortex but is generally more robust in bilateral frontal cortices, superior temporal regions, and supramarginal gyri (13). Several studies have shown that global cortical gyrification reflected by GI decreases with age in several cross-sectional samples, and topography of these changes is different from CT (14,15). Age relates to lower gyrification mainly in the parietal, frontal, temporal, and occipital regions (16).…”

Quantifying the trajectory of gyrification changes in the aging brain (Commentary on Madan, 2021)

“…However there is a more prominent decrease in GI in the parietal cortex, which is a relatively more folded region. Madan (2021) extends this analysis by showing that the change in GI is driven by changes in the morphology of the sulci, becoming shallower and wider as the brain ages (see also Madan, 2019). These changes to the sulci are obvious in the slices in Figure 1, which are taken roughly through the regions with the greatest GI change in Madan's analysis.…”

“…In understanding these changes, it is helpful to have measures that capture the changes with sufficient sensitivity that individual differences can be explored. Madan (2021) tackles this problem by looking at the gradients of gyrification across the brain. Madan uses a gyrification index (GI) that captures the smoothness of the brain at each point on its surface (Schaer et al, 2012;Zilles et al, 1988).…”

“…Previous studies have used crosssectional data to infer age-related changes in GI, finding that gyrification decreases during aging. Here, Madan (2021) uses longitudinal data to examine within-subject trajectories (LaMontagne et al, 2019). The main finding here is that the changes in gyrification are not uniform across the brain.…”