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Updated: Aug 28, 2026
A Pilot Study on the Repetitive Transcranial Magnetic Stimulation of Aβ and Tau Levels in Rhesus Monkey Cerebrospinal Fluid
Published on: September 3, 2021
Rs-fMRI reveals that taVNS improves cognitive and emotional function in mild cognitive impairment by reconfiguration
Tianjiao Xu1, Chunlei Guo1, Lei Zhang1
1Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
Background:
Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising noninvasive intervention for mild cognitive impairment (MCI), but its clinical efficacy and network-level mechanisms remain unclear.
Methods:
In this prospective, randomized, sham-controlled, parallel-group trial, 60 patients with MCI were assigned 1:1 to 12-week taVNS or sham taVNS. The primary outcome was the between-group difference in change from baseline to week 12 on the Montreal Cognitive Assessment-Basic (MoCA-B). Secondary outcomes included AVLT-H, STT-A/B, AFT, BNT, HAMD-17, and HAMA scores. Twenty-eight healthy controls underwent baseline rs-fMRI as a non-randomized reference cohort. Functional connectivity (FC) identified MCI-related abnormal regions, which together with theory-driven regions served as seeds for Granger causality analysis (GCA) to characterize intervention-related effective connectivity changes. Imaging-behavior associations were examined using Pearson correlations. The final per-protocol analysis included 52 randomized patients with complete clinical and imaging data.
Results:
After 12 weeks, the taVNS group showed significant within-group improvements in global cognition and multiple secondary outcomes, whereas the sham group did not. The between-group difference in MoCA-B change was significant (mean difference = 2.91, 95% CI: 0.79 to 5.03, Cohen's d = 0.59), indicating a moderate-to-large effect. Baseline FC abnormalities in MCI mainly involved the insula, medial frontal cortex, precuneus, temporal cortex, thalamus, cingulate cortex, and parieto-occipital regions. Following taVNS, effective connectivity was selectively reconfigured within a distributed network centered on the insula, anterior cingulate cortex, temporal cortex, and precuneus. Changes in directed connectivity correlated with changes in MoCA-B, AFT, and HAMA scores. No serious adverse events occurred.
Clinical Trial Registration:
https://www.chictr.org.cn/showproj.html?proj=131823, identifier (ChiCTR2100049940).
