Patterns of hippocampal atrophy differ among Alzheimer's disease, amnestic mild cognitive impairment, and late-life depression

Aim This study investigated whether the characteristic changes in hippocampal atrophy seen in coronal scans are useful for differentiating Alzheimer's disease (AD), amnestic mild cognitive impairment (aMCI), and major depressive disorder (MDD). Methods Subjects included 58 patients with AD, 33 with aMCI, 20 with MDD, and 22 normal controls, all aged 60 years or older. For each subject, eight coronal short TI inversion recovery images perpendicular to the hippocampal longitudinal axis were obtained. Images were manually measured using the conventional region of interest method of quantitative analysis. Results The overall trend in the corrected volumes of the hippocampus was AD < aMCI < MDD < normal controls. We found atrophy in all slices in AD, atrophy centred on the hippocampal head in aMCI, and atrophy in the slice of the hippocampal body 12 mm from the amygdala in MDD. Conclusions The present study suggested that our method of comparing hippocampal atrophy by region may be useful in distinguishing AD, aMCI, MDD, and normal controls.