Automated segmentation of hippocampal subfields in drug-naive patients with Alzheimer's disease

Background: Although a few automated hippocampal subfields segmentation methods were developed, the effects of diagnosis of Alzheimer’s disease (AD) on the hippocampal subfields volumes in vivo MRI were not clear. The aim of this study was to investigate hippocampal subfields volumes difference between AD subjects and health elderly controls using automated hippocampal subfields segmentation technique. Methods: Fifty drug-naive subjects with AD and 49 group-matched healthy control subjects underwent 3T MRI scanning, and hippocampal subfields volumes were measured and compared between the groups. Additionally, we explored the correlation pattern between hippocampal subfields volumes and the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD-K) verbal delayed recall score in AD subjects. Results: Subjects with AD exhibited significant hippocampal volume reductions in the presubiculum, subiculum and cornu ammonis (CA) 2-3 areas compared with healthy subjects (uncorrected, P<0.001). Significant correlations were observed between hippocampal deformations in the presubiculum/subiculum areas and CERAD-K verbal delayed recall scores (uncorrected, P< 0.001). Conclusions: This study is the first to elaborate the subfields volume differences between the controls and AD patients using the automated hippocampal subfields segmentation by Van Leemput et al. These structural changes in the hippocampal presubiculum, subiculum and CA23 areas might be at the core of underlying neurobiological mechanisms of hippocampal dysfunction and their relevance to verbal delayed recall impairments in AD.