Large-scale dynamic functional connectivity alterations in subjective cognitive decline: a rs-fMRI study on 5T MRI

Motivation: Subjective cognitive decline (SCD) is considered to be the best window period for early diagnosis and intervention of Alzheimer’s disease (AD). However, large-scale dynamic functional connectivity (DFC) alterations in this stage remain unclear. Goal(s): To assess alterations in large-scale DFC in SCD patients on 5T MRI. Approach: With a sliding-window approach and k-means clustering based on independent component analysis, rs-fMRI of high spatial-temporal dimension was used to evaluate large-scale DFC properties in SCD and normal control (NC) on 5T MRI. Results: Four distinct functional states were identified. DFC properties were statistically significantly different between SCD and NC in state 2 and state 3. Impact: Our study is the first successful attempt in fMRI of high spatio-temporal dimension on 5T MRI datasets. Altered temporal properties in large-scale DFC may serve as sensitive neuroimaging biomarkers for the preclinical detection of individuals with incipient AD.