Purpose: To describe loss of cortical thickness and ventricular enlargement during normal aging in a sample of 525 neurologically and psychiatrically inconspicuous subjects (17-68 years old).
Materials and methods: An automated segmentation algorithm was applied to assess cortical thickness and compared with conventional measurements of ventricular indices (ventricular body index (VBI), anterior horn index (AHI), and third ventricular width) as performed in clinical practice. Regression analysis was performed to elucidate the relationship between a decrease of the cortical mantle and increase in ventricular width with aging.
Results: Cortical thickness decreases with age (r = -0.49, P < 0.01; r = -0.502 in male and r = -0.461 in female subjects). Regarding the ventricular indices, we found a significant correlation with age for both the whole sample and the subdivision by gender. Cortical thickness and ventricular width are closely correlated (r = -0.43 in women, r = -0.468 in men, P < 0.001 each). The bandwidth of variance scales up with aging in all parameters. The results are discussed in terms of the underlying mechanisms of normal aging.
Conclusion: Our findings suggest that a decrease in cortical thickness and increase in ventricular width occur with normal aging. The enlargement of the third ventricle correlates the most strongly with age.