Speech Pathology and Audiology Program, Swallowing Physiology & Rehabilitation Research Laboratory, School of Health Sciences, Kent State University, PO Box 5190, Kent, OH, 44242-0001, USA.
Department of Speech, Language, and Hearing Sciences, Upper Airway Dysfunction Lab, Gainesville, FL, USA.
Dysphagia. 2019 Aug;34(4):529-539. doi: 10.1007/s00455-019-09991-y. Epub 2019 Feb 28.
Limited research in swallowing physiology has suggested that the most common existing transcutaneous electrical stimulation (TES) protocol (VitalStim) may not penetrate to layers of tissue to affect deep swallowing muscles. TES amplitude is the primary parameter that determines the depth of electrical current penetration (DECP). Preliminary work suggests that replacing a long-pulse duration with a short-pulse duration can increase maximum amplitude tolerance (MAT) within subjects' comfort level. Increasing MAT may indicate a higher DECP. The current study evaluates this premise in reference to the effects of varying pulse duration on lingual-palatal pressure during swallowing. Thirty healthy older adults (60-70 years of age) participated in this study. Each subject swallowed three trials of 10 mL pudding under three TES conditions: no stimulation, short-pulse duration, and long-pulse duration. TES was delivered using two pairs of surface electrodes on the submental muscles. MAT and perceived discomfort levels were identified separately for short and long-pulse TES conditions. Lingual-palatal peak pressure, pressure integral, and pressure duration were measured under each condition. Two-way repeated measures ANOVAs were conducted to identify within subject effects of TES condition and tongue bulb location. Lingual-palatal pressure and pressure integral were significantly reduced in the short-pulse duration condition. MAT was significantly higher in the short-pulse duration versus the long-pulse duration condition. Furthermore, MAT was significantly correlated with lingual-palatal pressure. Changing pulse duration had no significant impact on tongue pressure duration. Results suggest that a short-pulse duration may penetrate deeper into muscles involved in swallowing. The specific impact is reflected in a reduced upward pressure of the tongue on the palate during swallowing. This 'restrictive' effect of TES on tongue pressure may have the potential to be used during a resistive exercise paradigm for tongue elevation during swallowing.
吞咽生理学的有限研究表明，最常见的现有经皮电刺激 (TES) 方案 (VitalStim) 可能无法穿透组织层来影响深层吞咽肌肉。TES 幅度是决定电流穿透深度 (DECP) 的主要参数。初步研究表明，用短脉冲持续时间代替长脉冲持续时间可以在受试者的舒适水平内增加最大幅度耐受 (MAT)。增加 MAT 可能表明更高的 DECP。本研究评估了这一前提，即在吞咽时，不同脉冲持续时间对舌腭压力的影响。30 名健康老年人 (60-70 岁) 参加了这项研究。每位受试者在三种 TES 条件下吞咽 10 毫升布丁 3 次：无刺激、短脉冲持续时间和长脉冲持续时间。TES 通过颏下肌肉上的两对表面电极进行传输。分别为短脉冲和长脉冲 TES 条件确定 MAT 和感知不适水平。在每种条件下测量舌腭峰值压力、压力积分和压力持续时间。进行了双因素重复测量方差分析，以确定 TES 条件和舌球位置的受试者内影响。短脉冲持续时间条件下的舌腭峰值压力和压力积分显著降低。短脉冲持续时间与长脉冲持续时间相比，MAT 显著升高。此外，MAT 与舌腭压力显著相关。改变脉冲持续时间对舌压持续时间没有显著影响。结果表明，短脉冲持续时间可能会更深地穿透参与吞咽的肌肉。具体影响反映在吞咽时舌对 palate 的向上压力减小。TES 对舌压的这种“限制”作用可能具有在吞咽时用于舌提升的抗阻运动范式中的应用潜力。
