Functional connectivity patterns of the cerebellar components of intrinsic connectivity networks in clinically diagnosed probable Alzheimer's disease.

BACKGROUND

This study investigated the functional connectivity (FC) patterns of cerebellar components of seven intrinsic connectivity networks (ICNs) across different stages of Alzheimer's disease (AD).

METHODS

FC between each cerebellar seed region corresponding to one of the seven ICNs and 91 cerebral regions of interest (ROI) corresponding to the cortical parcels defined by Harvard-Oxford atlas was calculated for individuals with clinically diagnosed probable AD dementia (n = 21), mild cognitive impairment (n = 34), and subjective cognitive decline (n = 33). Group differences were assessed using ANOVA with false discovery rate (FDR) correction for multiple ROIs (pFDR-corr<0.05).

RESULTS

Significant alterations were observed in FC between the frontoparietal network (FPN) and the left superior frontal gyrus (SFG), as well as between the limbic network (LN) and the right superior lateral occipital cortex (sLOC) and temporo-occipital middle temporal gyrus (toMTG). Specifically, FPN-SFG connectivity decreased at the dementia stage, while LN-toMTG and LN-sLOC connectivity decreased during the prodromal stage but increased in the dementia stage.

CONCLUSIONS

These results indicate the presence of both decreases and increases in cerebellar-cortical FC across different stages of AD. A detailed examination of cerebellar involvement, an aspect often underexplored in AD research, may be crucial for understanding the neural mechanisms underlying disease progression.