Longitudinal changes in grey matter and cognitive performance over four years of healthy aging

Normal aging is known to include declines in several cognitive domains, with parallel grey matter atrophy. However, there are inconsistencies in the largely cross-sectional literature as to which regions of grey matter show change over time, with some investigations reporting whole brain and others reporting more focal regions of atrophy. More longitudinal analyses are needed to better understand the neurostructural and functional changes that occur gradually in older adulthood.

The aim of the current study was to investigate changes in cognitive performance and grey matter atrophy in a sample of healthy older adults over four years.

MRI and cognitive data were retrieved from the Alzheimer's Disease Neuroimaging Initiative database for 35 participants in the cognitively normal cohort at two time points separated by four years (mean age at baseline = 75.02, SD = 6.51, 54% female). Grey matter structure was assessed via voxel-based morphometry and cognition was measured across four domains (memory, executive function, language and visuospatial skills).

Results indicated widespread grey matter atrophy, including frontal, temporal, and subcortical regions. Cognitive performance was largely stable, with the exception of executive function, which showed significant decline over time.

Findings indicate that cognitive abilities are largely preserved over a four year period, even when grey matter atrophy is present in the aging brain.