Repetitive Transcranial Magnetic Stimulation Alters Brain Communication Networks to Improve the Cognitive Function in Patients with Amnestic Mild Cognitive Impairment - A Clinical Trial

Introduction: Repetitive Transcranial Magnetic Stimulation (rTMS) is a non-invasive intervention that could effectively enhance the cognitive function in patients with amnestic mild cognitive impairment (aMCI). However, the mechanism and predictive biomarkers for therapeutic response remain poorly understood. Methods: Fifty-three aMCI patients underwent either neuro-navigated rTMS (n=28) or sham stimulation (n=25) targeting the left angular gyrus over four weeks (registered in 2021: ChiCTR2100050496). Multimodal MRI and comprehensive neuropsychological assessments were conducted pre- and post-intervention. Changes in brain communication networks and their correlation with cognitive improvements were analysed, with random forest models applied to predict treatment efficacy. Results: Episodic memory (p< 0.001) and general cognitive function (p< 0.05) of aMCI patients were significantly improved after intervention. Novel alterations in brain communications networks were identified in 5 sensorimotor areas, executive control regions, and emotion-cognition processing hubs. Communication alterations between the right precentral gyrus and right angular gyrus were positively correlated with the improvements in episodic memory (r=0.38, p=0.046), while the alterations between right precentral gyrus and right angular gyrus were negatively correlated with improvements in general cognitive function (MMSE, r=-0.44, p=0.019; MoCA, r=-0.43, p=0.024). Notably, the random forest model integrating communication network patterns with baseline demographic and neuropsychological data showed strong power in predicting rTMS effects. Discussion: These findings advance understanding of rTMS mechanisms by linking network plasticity to cognitive gains, addressing critical knowledge gaps. Conclusion: Neuro-navigated rTMS targeting the left angular gyrus may enhance cognitive function in aMCI patients by improving inter-brain regions communication. Baseline communication patterns hold promise as predictive biomarkers, facilitating personalized treatment strategies.