Abnormal Regional and Global Connectivity Measures in Subjective Cognitive Decline Depending on Cerebral Amyloid Status

Background: Amyloid-? accumulation was found to alter precuneus-based functional connectivity (FC) in mild cognitive impairment (MCI) and Alzheimer’s disease (AD) dementia, but its impact is less clear subjective decline (SCD), which combination with AD pathologic change theorized correspond stage 2 of the continuum 2018 NIA-AA research framework. Objective: This study addresses how amyloid pathology relates resting-state fMRI FC SCD, especially focusing on precuneus. Methods: From DELCODE cohort, two groups 24 age- gender-matched amyloid-positive (SCDA?+) amyloidnegative SCD (SCD??) patients were selected according visual [18F]-Florbetaben (FBB) PET readings, studied fMRI. Local (regional homogeneity [ReHo], fractional amplitude low-frequency fluctuations [fALFF]) global (degree centrality [DC], precuneus seed-based FC) measures compared between groups. Follow-up correlation analyses probed relationships group differences precuneal load, as measured by FBB standard uptake value ratios (SUVR=?FBB). Results: ReHo significantly higher (voxel-wise p < 0.01, cluster-level 0.05) bilateral for SCDA?+patients, whereas fALFF not altered Relatively occipital areas (but no DC) observed SCDA?+ patients. In this latter cluster, precuneus-occipital correlated positively SUVRFBB (both groups). Conclusion: While partial confounding influences due a APOE ?4 carrier ratio among cannot be excluded, exploratory results indicate alterations hub region that related amyloid-? highlighting incipient continuum.