Hippocampal shape and cognitive performance in amnestic mild cognitive impairment.

Previous studies have carried out hippocampal shape analysis of amnestic mild cognitive impairment (aMCI) patients using automated segmentation techniques. However, the relationships between hippocampal deformations and various episodic memory impairments were not clear. The aim of this study was to investigate hippocampal shape changes and their relationships with various episodic memory impairments in aMCI. Hippocampal volumes and deformations were compared between the aMCI and the controls. In addition, we explored the correlation pattern between hippocampal deformations and cognitive dysfunctions in aMCI using a comprehensive neuropsychological battery. Patients with aMCI exhibited significant hippocampal deformations in the right cornu ammonis 1 (CA1) and subiculum areas compared with healthy individuals. Significant correlations were observed between constructional recall scores and the right CA1 and subiculum areas in aMCI. Verbal delayed recall scores were also significantly correlated with the left CA1 and subiculum areas in aMCI. This study was the first to explore the relationships between hippocampal deformations and various types of cognitive performances in aMCI. These structural changes in the hippocampal CA1 and subiculum areas might be at the core of underlying neurobiological mechanisms of hippocampal dysfunction and their relevance to verbal and visuospatial delayed recall in aMCI.