One-year age changes in MRI brain volumes in older adults

Longitudinal studies indicate that declines in cognition and memory acceler ate after age 70 years. The neuroanatomic and neurophysiologic underpinning s of cognitive change are unclear, as there is little information on longit udinal brain changes. We are conducting a longitudinal neuroimaging study o f nondemented older participants in the Baltimore Longitudinal Study of Agi ng. This report focuses on age and sex differences in brain structure measu red by magnetic resonance imaging during the first two annual evaluations. Cross sectional results from 116 participants aged 59-85 years reveal signi ficantly larger ventricular volumes and smaller gray and white matter volum es in older compared with younger participants and in men compared with wom en. Regional brain volumes show that the effects of age and sex are not uni form across brain regions. Age differences are greatest for the parietal re gion. Sex differences tend to be larger for frontal and temporal than parie tal and occipital regions. Longitudinal analysis demonstrates an increase o f 1526 mm(3) in ventricular volume over 1 year, but no detectable change in total or regional brain volumes. Definition of the pattern and rate of lon gitudinal brain changes will facilitate the detection of pathological brain changes, which may be predictors of dementia.