Structural and diffusion MRI measures of the hippocampus and memory performance

• DOI: 10.1016/j.neuroimage.2012.08.067
• Publication Date: 2012-08-30T17:31:08Z
• Authors: T. den Heijer; F. van der Lijn; M.W. Vernooij; M. de Groot; P.J. Koudstaal; A. van der Lugt; G.P. Krestin; A. Hofman; W.J. Niessen; M.M.B. Breteler
• Keywords: Male; 0301 basic medicine; Aging; EMC NIHES-01-64-01; anatomy & histology [Hippocampus]; physiology [Hippocampus]; Hippocampus; physiology [Psychomotor Performance]; Cohort Studies; 03 medical and health sciences; Memory; Image Processing, Computer-Assisted; psychology [Aging]; Humans; ddc:610; physiology [Memory]; physiology [Verbal Learning]; Aged; Aged, 80 and over; EMC NIHES-03-30-01; Middle Aged; Verbal Learning; physiology [Aging]; Magnetic Resonance Imaging; EMC NIHES-03-30-03; Diffusion Tensor Imaging; physiology [Mental Recall]; Data Interpretation, Statistical; Mental Recall; Educational Status; Female; Psychomotor Performance; EMC COEUR-09

Hippocampal atrophy on MRI and changes in diffusion tensor imaging (DTI) measures of the hippocampus have been reported in patients with Alzheimer's disease. We examined the association between hippocampal volumes, DTI measures of the hippocampus and memory performance in 892 non-demented persons (age ≥ 55 years) across different age groups. Hippocampal volume was segmented on 3D volumetric MRI scans. The segmentations were co-registered to mean diffusivity (MD) and fractional anisotropy (FA) maps to yield mean hippocampal MD and FA measurements. Higher MD of the hippocampus was associated with impaired verbal memory performance. In all persons ≥ 55 years, a higher MD of the hippocampus was associated with a worse memory performance. Hippocampal volumes were very weakly positively associated with delayed recall and only in persons > 65 years. FA of the hippocampus was not associated with memory performance. Follow-up studies will be needed to determine whether higher MD of hippocampus at younger ages could be an earlier marker of incident Alzheimer's disease than hippocampal volume.