Hippocampal Subfield Atrophy in Multi-Domain but Not Amnestic Mild Cognitive Impairment

To investigate differences in hippocampal (HP) subfields and the adjoining perirhinal and entorhinal cortices (PRC and ERC) between amnestic mild cognitive impairment (aMCI) and multi-domain amnestic MCI (mdMCI) patients, and controls.

Nineteen patients characterized as aMCI were compared with 24 mdMCI patients and 31 controls by means of an automatic HP segmentation procedure.

We found significant atrophy of the PRC and ERC in aMCI relative to controls, whereas a more pronounced pattern of atrophy in most subfields, including total HP volume, was found in the mdMCI group. The mdMCI group also had a significant cornu ammonis sector 4 region with dentate gyrus, subiculum and total HP atrophy relative to aMCI.

The aMCI group showed atrophy in the PRC and ERC, whereas significantly more affection of the HP subfields was evident in mdMCI. The mdMCI group may thus represent clinical progression relative to aMCI coupled with HP subfield affection.