A Systematic Review of Effect of Neuromuscular Electrical Stimulation on Physiological Measures of Swallow

Abstract

Neuromuscular electrical stimulation (NMES) has been gaining clinical interest in the field of dysphagia for over two decades. While there have been numerable normative and clinical experiments on this subject, the current study aimed to review the evidence for change in swallow-related physiology following NMES regimen in typical and clinical population. Following the recommended systematic review protocols, 19 studies could be included in this systematic review. The risk of bias assessment revealed high to some bias in most of the parameters. From the findings, tongue activity and hyolaryngeal elevation were the most experimented physiology in the context of NMES. While the stimulation resulted in significant changes in the tongue base retraction, anterior and superior elevation, the evidence for changes in upper esophageal sphincter activity was equivocal. Other pharyngeal physiologies were scarcely studied, and heterogeneity of methodological characteristics limited the possibility of statistical synthesis of the data. In conclusion, in spite of the number of the clinical research, NMES protocols and the clinical changes in physiology need to be explored further for the implementation of evidence-based practice.