Age-related changes in cortical and subcortical structures of healthy adult brains: A surface-based morphometry study.

BACKGROUND: Cerebral structures in both cortical and subcortical regions change with aging. More specific and comprehensive studies are needed to better elucidate these changes.

PURPOSE: To investigate the relationships between age and cerebral structures regarding cortical and subcortical changes.

STUDY TYPE: Cross-cohort research.

POPULATION: 54 healthy adults (28 females) aged 21-71 years.

FIELD STRENGTH/SEQUENCE: T1 -weighted imaging was performed at 1.5T.

ASSESSMENT: The cortical thickness, local gyrification index (LGI), and the volumes of total gray matter (GM), white matter (WM), white matter hyperintensity (WMH), deep gray matter nuclei (putamen, pallidum, thalamus, caudate, amygdala, accumbens area, and hippocampus), ventricles, and hippocampal subfields were obtained using FreeSurfer software.

STATISTICAL TESTS: Regression analysis was performed to determine the relationships between age and cortical thickness, LGI, and volumes of subcortical structures. Uncorrected P values ≤ 0.001 and R2  > 0.16 were considered significant.

RESULTS: The cortical thickness and LGI decreased with age throughout almost all brain regions (R2  > 0.16; P ≤ 0.001). Except for the volumes of the WM and 4th ventricle (R2  < 0.16; P > 0.001), the volumes of the GM, WMH, lateral ventricle, inferior lateral ventricle, and 3rd ventricle showed a nonlinear correlation with aging (R2  > 0.16; P ≤ 0.001). For deep gray matter nuclei, the thalamus volume was significantly decreased with aging (R2  = 0.256; P = 0.001). Additionally, the hippocampus volume was initially increased and then decreased at age of 50, mainly in the granule cell layer of the dentate gyrus (GC-DG), cornus ammonis 2/3 (CA2/3), CA4, and fissure (R2  > 0.16; P ≤ 0.001). The volumes of the putamen, pallidum, accumbens area, amygdala and caudate showed no significance with aging (R2  < 0.16; P > 0.001).

DATA CONCLUSION: The results comprehensively show the relationships between age and cerebral structures in multiple brain regions, and these findings may help identify normal aging and other age-related neuroradiological disorders.

LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018.