Tang Xiaorong, Xu Mindong, Zhao Jiayi, Shi Jiahui, Zi Yingyu, Wu Jianlu, Xu Jing, Yu Yanling, Yao LuLu, Ou Jiayin, Li Yitong, Yao Shuqi, Lv Hang, Lu Liming, Xu Nenggui, Wang Lin
South China Research Center for Acupuncture and Moxibustion, Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China.
Nanfang Hospital, Southern Medical University, Guangzhou, China.
Front Behav Neurosci. 2022 Feb 24;16:808789. doi: 10.3389/fnbeh.2022.808789. eCollection 2022.
The use of transcranial magnetic stimulation combined with electromyography for the functional evaluation of the cerebral cortex in both clinical and non-clinical populations is becoming increasingly common. Numerous studies have shown that electro-acupuncture (EA) can regulate cerebral cortical excitability. However, the effect of EA on the lateralization of the human swallowing motor cortex excitability is not yet fully understood.
The aim of this study was to assess whether lateralization is present in the swallowing motor cortex of healthy subjects, and to investigate the impact of EA at Lianquan (CV23) and Fengfu (GV16) on lateralization.
Forty subjects were randomized 1:1 into the EA group and the sham-EA group. The bilateral swallowing motor cortices was located by a neuroimaging navigation system. Then, the resting motor threshold (RMT) and motor evoked potential (MEP) of the mylohyoid of healthy subjects were recorded while applying combined transcranial magnetic stimulation and electromyography before and after EA or sham-EA.
First, the RMT and MEP latency of the contralateral mylohyoid innervated by the right swallowing cortex (71.50 ± 1.67%, 8.30 ± 0.06 ms) were lower than those innervated by the left (79.38 ± 1.27%, 8.40 ± 0.06 ms). Second, EA at CV23 and GV16 reduced the bilateral RMT and enhanced the bilateral MEP latency and amplitude ( = 0.005, < 0.001; = 0.002, = 0.001; = 0.002, = 0.009), while sham-EA did not ( > 0.05). Third, EA had an effect on the RMT and MEP latency in terms of lateralization changes, but this was not significant ( = 0.067, = 0.156).
The right swallowing motor cortex of healthy subjects is more excitable than that of the left at resting state. Thus, we found that lateralization is present in the swallowing motor cortex of healthy people, which might indicate a hemispheric dominance of swallowing predominates in the right swallowing motor cortex. In addition, EA at CV23 and GV16 can instantly promote the excitability of the bilateral swallowing motor cortices. But there was no significant difference in EA stimulation in terms of lateralization.
经颅磁刺激联合肌电图用于临床和非临床人群大脑皮层功能评估的应用日益普遍。大量研究表明，电针（EA）可调节大脑皮层兴奋性。然而，EA对人类吞咽运动皮层兴奋性偏侧化的影响尚未完全明确。
本研究旨在评估健康受试者吞咽运动皮层是否存在偏侧化，并探讨针刺廉泉（CV23）和风府（GV16）对偏侧化的影响。
40名受试者按1:1随机分为电针组和假电针组。采用神经影像导航系统定位双侧吞咽运动皮层。然后，在电针或假电针前后，应用经颅磁刺激联合肌电图记录健康受试者下颌舌骨肌的静息运动阈值（RMT）和运动诱发电位（MEP）。
首先，右侧吞咽皮层支配的对侧下颌舌骨肌的RMT和MEP潜伏期（71.50±1.67%，8.30±0.06 ms）低于左侧（79.38±1.27%，8.40±0.06 ms）。其次，针刺CV23和GV16可降低双侧RMT，增加双侧MEP潜伏期和波幅（P = 0.005，P < 0.001；P = 0.002，P = 0.001；P = 0.002，P = 0.009），而假电针则无此作用（P > 0.05）。第三，电针在偏侧化变化方面对RMT和MEP潜伏期有影响，但差异不显著（P = 0.067，P = 0.156）。
健康受试者在静息状态下，右侧吞咽运动皮层比左侧更易兴奋。因此，我们发现健康人吞咽运动皮层存在偏侧化，这可能表明右侧吞咽运动皮层在吞咽方面存在半球优势。此外，针刺CV23和GV16可即刻提高双侧吞咽运动皮层的兴奋性。但电针刺激在偏侧化方面无显著差异。
