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[P3–358]: SELECTIVE AGE‐ASSOCIATION OF HIPPOCAMPAL SUBFIELDS IN COGNITIVELY HEALTHY ELDERLY
Author(s) -
Dore Vincent,
Bourgeat Pierrick,
La Joie Renaud,
Flores Robin,
Fazlollahi Amir,
Fripp Jurgen,
Villemagne Victor L.L.,
Rowe Christopher C.,
Chetelat Gael,
Salvado Olivier
Publication year - 2017
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2017.06.1574
Subject(s) - subiculum , entorhinal cortex , dentate gyrus , hippocampal formation , hippocampus , atrophy , neuroscience , medicine , dementia , neurodegeneration , psychology , audiology , disease
aged 19-82years with MRI and neuropsychological tests (meanage1⁄457.61,615.08SD). Exclusion: stroke, major-brain-pathologies, central-nervous-medication. Independent Variables:Volume of hippocampus and its subfields (CornuAmmonis1, 2-3, 4-DentateGyrus, (Pre-)subiculum).DependentVariables:Verbalword-list learning, verbal-fluency, TrailMakingTask-(TMT)-A&B. Covariates: sex, age, years-of-education, total grey-matter-volume Image Analysis on high-resolution T1-images assessed at 3T. Hippocampal volumes were estimated using automatic segmentation analysis implemented in FreeSurfer (www.freesurfer.net). Statistical Analysis: Independent and dependent variables were first entered into Pearson Correlations. Variableswith a correlation coefficient of r>0.1were entered intomultiple linear-regressions and adjusted for potential confounding (forward inclusion-model). Results: According to bivariate correlations, better performance in verbal-learning, verbal-fluency and TMT-A&B correlated moderately with larger whole-hippocampal volume and the volumes of all subfields(all jrj>0.102, all p<0.002;Fig.1) except CA1 showing a weak positive correlation with TMT-A&B only(all jrj>0.046, all p<0.046).Linear regressions controlling for age, sex, education and total grey matter volume indicated that whole-hippocampal volume significantly explained 0.2% variance of verbal-learning performance (p1⁄40.01, b1⁄40.054) and CA4-DG volume explained 0.5% of the variance in TMT-A performance(p1⁄40.001, b1⁄4-0.054). Verbal-fluency, TMT-B, as well as other subcortical structures such as the thalamus were not associated with cognitive performance after controlling for confounders (p>0.5). Conclusions: Using a large cross-sectional cohort of healthy adults we found that volumes of the whole-hippocampus and subfields covering the CA4/dentate-gyrus region were weakly, yet specifically associated with verbal-learning and spatial processing-speed. Our preliminary results are in linewith previous studies presumingadifferential involvement of the hippocampus in tasks of verbal-learning and spatial processing (Oosterman,2010). Upcoming analyses implementing parcellation along the anterior-posterior-axis and random-effect-models might help to further disentangle these effects.