Altered functional connectivity strength in informant‐reported subjective cognitive decline: A resting‐state functional magnetic resonance imaging study

Abstract

Abstract Introduction Informant‐reported subjective cognitive decline (iSCD) has been associated with a higher risk of conversion to dementia, but the findings of whole brain functional connectivity strength (FCS) changes in iSCD are limited. Methods The sample comprised 39 participants with iSCD and 39 age‐ and sex‐ matched healthy controls. The global absolute (aFCS) and relative functional connectivity strengths were estimated using weighted degree centrality and the z‐scores of the weighted degree centrality respectively. FreeSurfer was used for measuring cortical thickness. Results The aFCS was lower in iSCD primarily in left medial superior frontal, left precuneus, left parietal, right cuneus, and bilateral calcarine; while relative functional connectivity strength was higher in posterior cingulate cortex/precuneus compared with healthy controls. No significant differences in cortical thickness were observed. Discussion There are detectable changes of FCS in iSCD, with the precuneus possibly playing a compensatory role. FCS could therefore have a potential role to serve as one of the earliest neuroimaging markers of neurodegenerative disease.

Keywords

• Subjective cognitive decline
• Functional connectivity strength
• Preclinical Alzheimer's disease
• Aging
• Precuneus