Focal hippocampal subfield atrophy in cognitively impaired relative to cognitively unimpaired older adults is associated with memory ability.

INTRODUCTION

We assessed whole hippocampal and subfield volumes, in association with memory ability, in a sample including cognitively unimpaired (CU) older adults and those in early syndromic stages of pathological aging, here subjective cognitive decline (SCD) and mild cognitive impairment (MCI).

METHODS

Participants completed a battery of neuropsychological tests and a 3T magnetic resonance imaging brain study that included high-resolution T2-weighted images of hippocampus and its subfields: subiculum; cornu ammonis 1, 2, and 3 (CA1, CA2, CA3); and dentate gyrus (DG).

RESULTS

Significant differences were found in the left whole hippocampus, left subiculum, CA1, and DG volumes in the MCI group compared to the CU or SCD groups. Least absolute shrinkage and selection operator regression techniques revealed that left subiculum and left CA1 volume significantly predicted memory ability above and beyond whole hippocampal and other subfield volumes.

DISCUSSION: We found clinical differences in memory ability in older adults were associated with focal differences in specific hippocampal subfield volumes.