A longitudinal study of brain volume changes in normal aging

Purpose: To evaluate the effect of normal aging on brain volumes and examine the effects of age and sex on the rates of changes in global and regional brain volumes. Methods: A total of 199 normal subjects (65 females and 134 males, mean age = 56.4 +/- 9.9 years, age range = 38.1-82.9 years) were included in this study. Each subject was scanned twice, at an interval of about 2 years (range = 1.5-2.3 years). Two-time-point percentage brain volume change (PBVC) was estimated with SIENA 2.6. Results: The mean annualized PBVC was -0.23%/y. Analysis of covariance (ANCOVA) for annual brain volume changes revealed a main effect of age. There was no main effect of sex, nor was there a sex-by-age interaction. Voxel-wise analysis revealed a negative correlation between age and edge displacement values mainly in the periventricular region. Conclusions: The results of our study indicate that brain atrophy accelerates with increasing age and that there is no gender difference in the rate of brain atrophy. (C) 2011 Elsevier Ireland Ltd. All rights reserved.