Grey Matter Changes On Brain MRI In Subjective Cognitive Decline: A Systematic Review

Introduction: People with subjective cognitive decline (SCD) report cognitive deterioration. However, their performance in neuropsychological evaluation falls within the normal range. The present study aims to analyse whether structural magnetic resonance imaging (MRI) reveals grey matter changes in SCD population compared with healthy normal controls (HC). Methods: : Parallel systematic searches in PubMed and Web of science databases were conducted, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Quality assessment was completed using the Newcastle-Ottawa Scale (NOS) Results: : 51 MRI studies were included. 35 studies used a region of interest (ROI) analysis, 15 used a voxel-based morphometry (VBM) analysis, and 10 studies used a cortical thickness (CTh) analysis. 10 studies combined both, VBM or CTh analysis with ROI analysis. Conclusions: : Medial temporal structures, like the hippocampus or the entorhinal cortex (EC) seemed to present grey matter reduction in SCD compared with HC, but the samples and results are heterogeneous. Larger sample sizes could help to better determine if these grey matter changes are consistent in SCD subjects.