Effects of Sequential 4-Channel Neuromuscular Electrical Stimulation on Hyoid Excursion, Swallowing Safety and Oral Intake in Older Adults With Sarcopenic Dysphagia: A Randomized Controlled Trial.

Abstract

Background: Sequential 4-channel neuromuscular electrical stimulation (NMES) was originally developed to mimic the physiological activation sequence of the swallowing-related muscles; however, its efficacy in older adults with sarcopenic dysphagia remains unclear. This study investigated the effects of sequential 4-channel NMES on hyoid excursion, swallowing safety, and oral intake in older adults with sarcopenic dysphagia.

Methods: Forty older adults with sarcopenic dysphagia were randomly assigned to either the sequential 4-channel (n = 20) or the conventional 2-channel (n = 20) NMES groups. Both groups received NMES intervention for 30 min per session, five times per week, for 6 weeks. Outcome measures included anterior and superior hyoid excursion assessed using the videofluoroscopic swallowing study (VFSS), penetration-aspiration scale (PAS), and functional oral intake scale (FOIS). Two-way repeated-measures analysis of variance was conducted to evaluate group × time interaction effects.

Results: Significant group × time interaction effects were observed for anterior hyoid excursion (F = 18.46, p < 0.001, η²p = 0.327), superior hyoid excursion (F = 6.94, p = 0.012, η²p = 0.154), PAS (F = 7.96, p = 0.008, η²p = 0.173), and FOIS (F = 8.66, p = 0.006, η²p = 0.186). Overall, the 4-channel NMES group demonstrated greater improvements in hyoid excursion, swallowing safety, and oral intake function than the 2-channel NMES group.

Conclusion: These findings support the use of physiologically-sequenced stimulation as a promising rehabilitation strategy to address swallowing impairments associated with sarcopenic dysphagia.