Effect of submental surface neuromuscular stimulation on laryngeal vestibule opening in healthy volunteers at rest and during swallowing

Abstract

Objective: The aim of this study was to determine (a) whether submental electrical stimulation could induce hyolaryngeal movement in healthy adults, (b) the effect of submental surface electrical stimulation on hyolaryngeal movement during stimulated swallows in comparison to nonstimulated swallows, and (c) the effect of submental surface electrical stimulation on vestibular closing both during stimulated swallows and stimulation at rest. Methods: Seven healthy participants with a mean age was 51 ± 5.6 years were included in this study. Each participant received submental neuromuscular electrical stimulation and was given 5 mL of liquid barium to swallow both with and without stimulation. Six randomized trials were recorded—3 with submental surface stimulation and 3 without stimulation with at least one sham stimulation swallow trial at rest. Trials were recorded via videofluoroscopy. Results: A total of 82 trails were recorded. The results of this study indicated (a) there was a hyoid movement as a result of submental stimulation, (b) no laryngeal movement occurred as a result of stimulation, and (c) the vestibule opening size was larger during stimulated swallows as compared with nonstimulated swallows. Conclusion: This study shows that there is increased risk of aspiration with submental stimulation as a result of increased vestibular opening following submental neuromuscular electrical stimulation.