Repeated High-Definition Transcranial Direct Current Stimulation Modulated Temporal Variability of Brain Regions in Core Neurocognitive Networks Over the Left Dorsolateral Prefrontal Cortex in Mild Cognitive Impairment Patients

Article type: Research Article

Authors: Zhang, Yanchun^{a; b} | Li, Chenxi^c | Chen, Deqiang^d | Tian, Rui^b | Yan, Xinyue^b | Zhou, Yingwen^e | Song, Yancheng^e | Yang, Yanlong^e | Wang, Xiaoxuan^e | Zhou, Bo^a | Gao, Yuhong^f | Jiang, Yujuan^{b; *} | Zhang, Xi^{a; *}

Affiliations: [a] Department of Neurology, Second Medical Center, National Clinical Research Center for Geriatric Disease, Chinese PLA General Hospital, Beijing, China | [b] Department of Rehabilitation, Cangzhou Central Hospital, Cangzhoug, Hebei Province, China | [c] Department of the Psychology of Military Medicine, Air Force Medical University, Xi’an, Shaanxi, P.R. China | [d] Department of CT, Cangzhou Central Hospital, Cangzhoug, Hebei Province, China | [e] Department of MR, Cangzhou Central Hospital, Cangzhoug, Hebei Province, China | [f] Institute of Geriatrics, Second Medical Center, Chinese PLA General Hospital, Beijing, China

Correspondence: [*] Correspondence to: Xi Zhang, Department of Neurology, The Second Medical Centre, National Clinical Research Centre for Geriatric Diseases, Chinese PLA General Hospital, Beijing, 100853, P.R. China. Tel.: +86 010 66876097; E-mail: zhangxi@301hospital.com.cn. and Yujuan Jiang, Department of Rehabilitation, Cangzhou Central Hospital, Cangzhoug, Hebei Province, 061000, China. Tel.: +86 13315777985; E-mail: jyj098418@163.com.

Abstract: Background:Early intervention of amnestic mild cognitive impairment (aMCI) may be the most promising way for delaying or even preventing the progression to Alzheimer’s disease. Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that has been recognized as a promising approach for the treatment of aMCI. Objective:In this paper, we aimed to investigate the modulating mechanism of tDCS on the core neurocognitive networks of brain. Methods:We used repeated anodal high-definition transcranial direct current stimulation (HD-tDCS) over the left dorsolateral prefrontal cortex and assessed the effect on cognition and dynamic functional brain network in aMCI patients. We used a novel method called temporal variability to depict the characteristics of the dynamic brain functional networks. Results:We found that true anodal stimulation significantly improved cognitive performance as measured by the Montreal Cognitive Assessment after simulation. Meanwhile, the Mini-Mental State Examination scores showed a clear upward trend. More importantly, we found significantly altered temporal variability of dynamic functional connectivity of regions belonging to the default mode network, central executive network, and the salience network after true anodal stimulation, indicating anodal HD-tDCS may enhance brain function by modulating the temporal variability of the brain regions. Conclusion:These results imply that ten days of anodal repeated HD-tDCS over the LDLPFC exerts beneficial effects on the temporal variability of the functional architecture of the brain, which may be a potential neural mechanism by which HD-tDCS enhances brain functions. Repeated HD-tDCS may have clinical uses for the intervention of brain function decline in aMCI patients.

Keywords: High-definition transcranial direct current stimulation (HD-tDCS), mild cognitive disorder, temporal variability, triple network model

DOI: 10.3233/JAD-220539

Journal: Journal of Alzheimer's Disease, vol. 90, no. 2, pp. 655-666, 2022