Modulations of static and dynamic functional connectivity among brain networks by electroacupuncture in post-stroke aphasia

Minjie Xu; Ying Gao; Hua Zhang; Binlong Zhang; Tianli Lyu; Zhongjian Tan; Changming Li; Xiaolin Li; Xing Huang; Qiao Kong; Juan Xiao; Georg S Kranz; Shuren Li; Jingling Chang

doi:10.3389/fneur.2022.956931

Modulations of static and dynamic functional connectivity among brain networks by electroacupuncture in post-stroke aphasia

Front Neurol. 2022 Dec 1:13:956931. doi: 10.3389/fneur.2022.956931. eCollection 2022.

Authors

Minjie Xu^{1

2}, Ying Gao^{1

3}, Hua Zhang¹, Binlong Zhang¹, Tianli Lyu¹, Zhongjian Tan¹, Changming Li¹, Xiaolin Li¹, Xing Huang¹, Qiao Kong¹, Juan Xiao¹, Georg S Kranz^{4

5

6}, Shuren Li⁷, Jingling Chang^{1

3}

Affiliations

¹ Department of Neurology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China.
² Key Laboratory of Chinese Internal Medicine Ministry of Education, Beijing University of Chinese Medicine, Beijing, China.
³ Institute for Brain Disorders, Beijing University of Chinese Medicine, Beijing, China.
⁴ Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China.
⁵ The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR, China.
⁶ Department of Psychiatry and Psychotherapy, Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria.
⁷ Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.

Abstract

Introduction: Post-stroke aphasia (PSA) is a language disorder caused by left hemisphere stroke. Electroacupuncture (EA) is a minimally invasive therapeutic option for PSA treatment. Tongli (HT5) and Xuanzhong (GB39), two important language-associated acupoints, are frequently used in the rehabilitation of patients with PSA. Preliminary evidence indicated functional activation in distributed cortical areas upon HT5 and GB39 stimulation. However, research on the modulation of dynamic and static functional connectivity (FC) in the brain by EA in PSA is lacking.

Method: This study aimed to investigate the PSA-related effects of EA stimulation at HT5 and GB39 on neural processing. Thirty-five participants were recruited, including 19 patients with PSA and 16 healthy controls (HCs). The BOLD signal was analyzed by static independent component analysis, generalized psychophysiological interactions, and dynamic independent component analysis, considering variables such as age, sex, and years of education.

Results: The results revealed that PSA showed activated clusters in the left putamen, left postcentral gyrus (PostCG), and left angular gyrus in the salience network (SN) compared to the HC group. The interaction effect on temporal properties of networks showed higher variability of SN (F = 2.23, positive false discovery rate [pFDR] = 0.017). The interaction effect on static FC showed increased functional coupling between the right calcarine and right lingual gyrus (F = 3.16, pFDR = 0.043). For the dynamic FC, at the region level, the interaction effect showed lower variability and higher frequencies of circuit 3, with the strongest connections between the supramarginal gyrus and posterior cingulum (F = 5.42, pFDR = 0.03), middle cingulum and PostCG (F = 5.27, pFDR = 0.036), and triangle inferior frontal and lingual gyrus (F = 5.57, pFDR = 0.026). At the network level, the interaction effect showed higher variability in occipital network-language network (LN) and cerebellar network (CN) coupling, with stronger connections between the LN and CN (F = 4.29, pFDR = 0.042). Dynamic FC values between the triangle inferior frontal and lingual gyri were anticorrelated with transcribing, describing, and dictating scores in the Chinese Rehabilitation Research Center for Chinese Standard Aphasia Examination.

Discussion: These findings suggest that EA stimulation may improve language function, as it significantly modulated the nodes of regions/networks involved in the LN, SN, CN, occipital cortex, somatosensory regions, and cerebral limbic system.

Keywords: brain networks; electroacupuncture; functional connectivity; independent component analysis; post stroke aphasia; psychophysiological interaction analysis.