Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Division of Diabetes, Endocrinology and Gastroenterology, Faculty of Biology, Medicine and Health, Centre for Gastrointestinal Sciences, Clinical Sciences Building, Salford Royal NHS Foundation Trust, School of Medical Sciences, The University of Manchester, Manchester, UK.
Neurogastroenterol Motil. 2021 Sep;33(9):e14173. doi: 10.1111/nmo.14173. Epub 2021 Jun 3.
Transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS) have been shown to have physiological and functional effects on brain excitability and motor behavior. Yet, little is known about their effects in the swallowing system.
To examine the effects and optimal stimulation parameters of tACS and tRNS for modulating excitability of human pharyngeal motor cortex.
10 Hz (alpha), 20 Hz (beta), 70 Hz (gamma) tACS, 0.1-640 Hz (full-spectrum) tRNS, and sham were applied over pharyngeal motor cortices at 1.5 mA current intensity for 10 min in 15 healthy participants. Pharyngeal motor-evoked and thenar motor-evoked potentials (PMEPs and TMEPs) were assessed before and up to 2 h after stimulation with single-pulse transcranial magnetic stimulation. Averaged MEP amplitude and latency changes were analyzed using repeated measures ANOVA (rmANOVA).
Two-way rmANOVA across all active interventions demonstrated a significant MEP interaction both in the stimulated pharyngeal cortex (F (4, 56) = 1.731, p = 0.038) and in the ipsilateral thenar cortex (F (4, 56) = 1.506, p = 0.048). Compared to sham, subsequent post hoc tests showed site-specific and sustained (60-120 min) increases in PMEPs with gamma tACS and tRNS (p = 0.005, p = 0.027, respectively) and for TMEPs with beta tACS (p = 0.006).
Our findings suggest that the effects of tACS and tRNS are frequency-dependent and cortical (representation) site-specific with both gamma tACS and full-spectrum tRNS enhancing human pharyngeal cortical excitability. These techniques hold promise as potential treatments for neurological dysphagia.
经颅交流电刺激（tACS）和经颅随机噪声刺激（tRNS）已被证明对大脑兴奋性和运动行为具有生理和功能影响。然而，对于它们在吞咽系统中的作用知之甚少。
研究 tACS 和 tRNS 调节人类咽运动皮层兴奋性的作用及最佳刺激参数。
在 15 名健康参与者中，使用 1.5 mA 电流强度，将 10 Hz（α）、20 Hz（β）、70 Hz（γ）tACS、0.1-640 Hz（全频谱）tRNS 和假刺激应用于咽运动皮层 10 分钟。使用单脉冲经颅磁刺激在刺激前和刺激后 2 小时评估咽运动诱发电位（PMEPs）和鱼际运动诱发电位（TMEPs）。使用重复测量方差分析（rmANOVA）分析平均 MEP 幅度和潜伏期变化。
对所有主动干预的双因素 rmANOVA 显示，在刺激的咽皮质（F（4, 56）= 1.731，p = 0.038）和同侧鱼际皮质（F（4, 56）= 1.506，p = 0.048）中均存在显著的 MEP 相互作用。与假刺激相比，随后的事后检验显示，γ tACS 和 tRNS 可使 PMEPs 出现部位特异性和持续（60-120 分钟）增加（p = 0.005，p = 0.027），β tACS 可使 TMEPs 增加（p = 0.006）。
我们的研究结果表明，tACS 和 tRNS 的作用与频率有关，且与皮质（代表）部位有关，γ tACS 和全频谱 tRNS 均可增强人类咽皮质兴奋性。这些技术有望成为治疗神经源性吞咽困难的潜在方法。
