Abstract
BACKGROUND: Laryngeal vestibule closure (LVC) is one of the critical airway protection mechanisms during swallowing. LVC timing impairments during swallowing are among the common causes of airway invasion in patients with dysphagia. OBJECTIVES: To understand whether using submental transcutaneous electrical stimulation (TES) with varying pulse durations can impact the LVC reaction time (LVCrt) and LVC duration (LVCd) measures in healthy adults. METHODS: Twenty-six healthy adults underwent three TES conditions while receiving three trials of 10 ml pureed: no TES, TES with short pulse duration (300 μs) and TES with long pulse durations(700 μs). Two pairs of electrodes were placed diagonally on the submental area. For each active TES condition, the stimulation was increased up to the participant's self-identified maximum tolerance. Each swallow trial was recorded using videofluoroscopic swallowing study. All data were extracted and analysed offline using VideoPad Video Editor program. RESULTS: Submental TES reduced LVCrt during swallowing [F (2, 46) = 7.234, p < .007, ηp2 = .239] but had no significant impact on LVCd [F (2, 50) = .1.118, p < .335, ηp2 = .043]. Furthermore, pulse duration had no distinguished impact on any LVC timing measures. CONCLUSION: Transcutaneous electrical stimulation may benefit patients with dysphagia who suffer from delayed LVC during swallowing. Future studies should seek whether the same physiologic effect can be observed in patients with dysphagia.