Hippocampal atrophy in persons with age-associated memory impairment: Volumetry within a common space

Objective: The objective of this study is to demonstrate the assessment of hippocampal atrophy within a standard brain atlas for persons with age-associated memory impairment (AAMI) compared with cognitively intact elderly. Methods: High-resolution three-dimensional (3D) brain magnetic resonance imaging (MRI) was performed on 20 nondemented persons: 10 had AAMI and 10 were normal elderly. Scans were aligned to a common atlas template to control for errors due to variable brain size and orientation as well as facilitating communication of results across centers. Manual outlining every 1 mm with volumes determined for both the hippocampal head and body was accomplished after coronal resampling perpendicular to the long axis of the hippocampus. Results: Subject groups were similar in age, sex ratios, and educational achievement. The AAMI group had significantly lower volumes for the right hippocampus and hippocampal head (p = .02) compared with controls. Conclusion: A growing body of work suggests the right hippocampal head as an early site of atrophy in early memory impairment. Subtle atrophic changes are detectable within a common atlas template allowing imaging assessment across centers.