Ogura Michihiro, Matsumoto Shuji, Ohama Rintaro, Ohama Yumi, Arima Haruka, Takenaka Keita, Toyama Keiichi, Ikegami Toshiyuki, Shimodozono Megumi
Department of Rehabilitation, Kagoshima University Hospital, Kagoshima, Japan.
Department of Rehabilitation and Physical Medicine, Mito Clinical Education and Training Center, Tsukuba University Hospital, Mito-kyodo Hospital, Mito, Japan.
Prog Rehabil Med. 2022 Jul 9;7:20220033. doi: 10.2490/prm.20220033. eCollection 2022.
This study examined the immediate effects of neuromuscular electrical stimulation (NMES) on the dynamics of oropharyngeal structure and laryngeal vestibular closure (LVC) in healthy subjects.
Ten healthy male volunteers participated in this controlled, before-and-after, videofluoroscopic swallowing pilot study. The study was conducted in four phases (each performed twice): (1) saliva swallow (SS) before evaluation (BEFORE), (2) NMES while at rest with no SS (NMES AT REST), (3) SS during NMES (DURING NMES), and (4) SS to examine the aftereffects of NMES (AFTER). We measured distances that oropharyngeal structures moved in the NMES AT REST phase, and we analyzed the kinematics of saliva swallowing primarily in the BEFORE and AFTER phases.
Four changes in the morphology of the oropharyngeal structure caused by NMES AT REST were statistically significant: anterior-upward displacement of the hyoid bone and larynx, stretch of the laryngeal vestibule, and posterior ridge of the tongue root. Regarding the kinematics measured during SS, although there was no significant change in LVC reaction times, LVC duration in the AFTER phase was significantly longer than BEFORE. Regarding maximal displacement of the hyoid bone, there was significantly greater movement AFTER than BEFORE. As additional exploratory outcomes, the velocity of hyoid bone movement was significantly slower, and the hyoid-to-larynx approximation was significantly smaller, DURING NMES than AFTER.
Longer duration of LVC might be caused by adaptive learning with NMES-induced structural changes in the oropharynx. Further clinical studies are warranted to determine whether this approach improves dysphagia, which impairs LVC.
本研究探讨了神经肌肉电刺激（NMES）对健康受试者口咽结构动力学和喉前庭关闭（LVC）的即时影响。
10名健康男性志愿者参与了这项对照、前后对比的视频荧光吞咽初步研究。该研究分四个阶段进行（每个阶段进行两次）：（1）评估前的唾液吞咽（SS）（评估前），（2）静息时无唾液吞咽的NMES（静息时NMES），（3）NMES期间的SS（NMES期间），以及（4）用于检查NMES后效应的SS（NMES后）。我们测量了静息时NMES阶段口咽结构移动的距离，并主要在评估前和NMES后阶段分析了唾液吞咽的运动学。
静息时NMES引起的口咽结构形态有四项变化具有统计学意义：舌骨和喉的向前向上移位、喉前庭的伸展以及舌根后嵴。关于SS期间测量的运动学，虽然LVC反应时间没有显著变化，但NMES后阶段的LVC持续时间明显长于评估前。关于舌骨的最大位移，NMES后比评估前有明显更大的移动。作为额外的探索性结果，NMES期间舌骨移动速度明显较慢，且舌骨与喉的接近程度明显小于NMES后。
LVC持续时间延长可能是由于NMES引起的口咽结构变化的适应性学习所致。需要进一步的临床研究来确定这种方法是否能改善损害LVC的吞咽困难。
