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Subjective cognitive decline correlates with medial temporal lobe and hippocampal subfield volumetry in cognitively unimpaired participants
Author(s) -
Operto Greg,
SánchezBenavides Gonzalo,
Domingo Gispert Juan,
Molinuevo Jose Luis
Publication year - 2020
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 - 10.1002/alz.043520
Subject(s) - temporal lobe , cognitive decline , neuropsychology , psychology , cognition , episodic memory , population , boston naming test , subiculum , audiology , verbal memory , dementia , medicine , hippocampal formation , neuroscience , disease , epilepsy , dentate gyrus , environmental health
Background Subjective cognitive decline (SCD) is a risk factor for cognitive decline and AD. SCD individuals display lower medial temporal lobe (MTL) volumes. Some features of SCD (SCD plus ), such as specific worry and recent onset, have been proposed as more related to AD pathology. In this study we aimed to explore the differences in MTL volumes between SCD and control individuals and their associations with memory performance in a large sample of cognitively unimpaired subjects. Methods 603 cognitively unimpaired individuals from a population‐based study (age: [47‐76], mean: 60.04∓6.57) underwent structural MRI, clinical and neuropsychological assessments. 184 were classified as SCD or 419 as Controls by their answers to the question “Do you perceive difficulties in memory or cognition as compared to how they used to be?”. A subgroup of 31 fulfilling two SCD plus criteria (Worry and Onset within last 5 years) was defined. Memory performance was assessed with the Free and Cued Selective Reminding Test (FCSRT). MTL and HS were segmented using ASHS using T1 and IR sequences. We compared regional volumes across SCD groups using linear models. Age, sex, education, APOE carriership and total intracranial volume were included as covariates. SCD group*memory scores interactions were assessed. Results SCD subjects showed lower volumes than Controls in right CA1 (p=0.031) and subiculum (p=0.026) (Figure 1). SCDplus subjects showed larger BA36 volumes in both hemispheres (Figure 2). In models comparing Controls and SCD plus we found a significant interaction (p=0.021) between SCD plus status and parahippocampal (PHC) bilateral volumes on FCSRT free recall score, with positive association in Controls and negative in SCD plus (poorer performance associated with larger PHC) (Figure 3). Conclusion As previously reported in smaller and older samples (Schwarz et al, AAIC 2019) a reduction of CA1 and subiculum was found in SCD subjects. Moreover, PHC volume correlates negatively with memory performance in SCD plus : this may pinpoint a transitional phase in the AD continuum with increments of cortical volume, as described in (Gispert et al., 2015; Fortea et al., 2011). Further work including CSF biomarkers will assess how these associations may be mediated by AD pathology.