Abstract
Sensitive measures of brain aging show great promise for gauging factors that affect aging and degenerative processes, such as risk genes or therapy. Here we examined age-related trends for three indices of cerebral health: gyral gray matter (GM) thickness, dilation of sulcal spaces with CSF, and the volume of T2-hyperintense white matter (HWM) lesions. The study involved 31 healthy adults age 57-82 years old. Measurements of average GM thickness, average sulcal span and HWM volume were performed using high-resolution 3D T1- and T2-weighted brain MR images. Age-related trends for the three cerebral health indices were consistent with previously published work though the analysis of their covariance led to a previously unreported relationship. Simultaneous multiple regression found that dilation of cortical sulci were primarily (t = 2.59, P < 0.01) related to the increases in HWM volume and secondarily related (t = -2.51, P < 0.01) to the reductions of the cortical GM thickness. The are-corrected correlation between reduction in GM thickness and increases in HWM volume, was not significant (P = 0.34). These findings are of interest in designing quantitative measures of brain aging for monitoring individual patients and in large-scale clinical trials.