Altered Effective Connectivity Within the Frontoparietal Network in Alzheimer's Disease and Its Modulation by Acupuncture: A Resting-State fMRI Study.

Abstract

Purpose: Alzheimer's disease (AD) is increasingly prevalent, yet how acupuncture modulates cognitive brain networks remains unclear. We used resting-state fMRI (rs-fMRI) to examine whether acupuncture prescription regulates effective connectivity within the frontoparietal network (FPN) in AD.

Patients and methods: Sixty AD patients were randomized to donepezil alone (drug group) or acupuncture plus donepezil (acupuncture group) for 6 weeks (n=30/group). Seven healthy controls were scanned once. Global cognition was assessed with MoCA-B. Independent component analysis identified the FPN, and Granger causality analysis quantified directed effective connectivity before and after treatment.

Results: Both interventions improved MoCA-B (P<0.05), with larger gains in the acupuncture group (P<0.05). Relative to controls, AD showed FPN disruption with compensatory reorganization. Decreased connectivity was observed from the left middle temporal gyrus (MTG) to the right inferior parietal lobule (IPL), and from the left median cingulate/paracingulate gyri (P<0.05). Increased connectivity emerged from the right IPL and left cingulate/paracingulate to the left MTG, and from the right IPL to the left medial frontal gyrus (orbital part) (P<0.05). The right IPL and left MTG were core FPN nodes. Post-treatment, the drug group showed reduced right IPL→left orbital medial frontal connectivity, whereas the acupuncture group showed reduced right IPL→left MTG connectivity (P<0.05). Between-group comparisons indicated acupuncture-specific modulation of right insula→left MTG and left precuneus→left MTG connectivity (P<0.05).

Conclusion: Acupuncture combined with donepezil provides superior cognitive benefits and selectively reshapes directed FPN interactions, supporting a network-level mechanism involving frontal-parietal-temporal integration.