Neurostimulation in People with Oropharyngeal Dysphagia: A Systematic Review and Meta-Analyses of Randomised Controlled Trials-Part I: Pharyngeal and Neuromuscular Electrical Stimulation.

Renée Speyer,Sarah Wilkes-Gillan,Bas Joris Heijnen,Reinie Cordier,Anna-Liisa Sutt,Shaheen Hamdy,Liza Bergström,Lianne Remijn

doi:10.3390/jcm11030776

Abstract

Objective. To assess the effects of neurostimulation (i.e., neuromuscular electrical stimulation (NMES) and pharyngeal electrical stimulation (PES)) in people with oropharyngeal dysphagia (OD). Methods. Systematic literature searches were conducted to retrieve randomised controlled trials in four electronic databases (CINAHL, Embase, PsycINFO, and PubMed). The methodological quality of included studies was assessed using the Revised Cochrane risk-of-bias tool for randomised trials (RoB 2). Results. In total, 42 studies reporting on peripheral neurostimulation were included: 30 studies on NMES, eight studies on PES, and four studies on combined neurostimulation interventions. When conducting meta analyses, significant, large and significant, moderate pre-post treatment effects were found for NMES (11 studies) and PES (five studies), respectively. Between-group analyses showed small effect sizes in favour of NMES, but no significant effects for PES. Conclusions. NMES may have more promising effects compared to PES. However, NMES studies showed high heterogeneity in protocols and experimental variables, the presence of potential moderators, and inconsistent reporting of methodology. Therefore, only conservative generalisations and interpretation of meta-analyses could be made. To facilitate comparisons of studies and determine intervention effects, there is a need for more randomised controlled trials with larger population sizes, and greater standardisation of protocols and guidelines for reporting.

Highlights

The aerodigestive tract facilitates the combined functions of breathing, vocalising, and swallowing
A total of 261 original articles were assessed at a full‐text level, with articles grouped based on type of intervention
As this systematic review reports on Pharyngeal Electrical Stimulation (PES) and neuromuscular electrical stimulation (NMES) interventions only, a final number of 42 studies reporting on peripheral neurostimulation were included in this review

Summary

Introduction

The aerodigestive tract facilitates the combined functions of breathing, vocalising, and swallowing. Any dysfunction in this system may lead to oropharyngeal dysphagia (OD) or swallowing problems [1]. OD can be the result of underlying diseases such as stroke or a progressive neurological disease (e.g., Parkinson’s disease, multiple sclerosis) or an adverse effect after head and neck oncological interventions (e.g., radiation or surgery) or intensive care treatment (e.g., intubation and tracheostomy). Prevalence estimates of OD have been reported to be as high as 50% in cerebral palsy [2], 80% in stroke and Parkinson’s disease, and over 90% in people with community‐acquired pneumonia [3]. Research has identified inverse bidirectional relationships between decreased health‐related quality of life and increased OD severity [4]

Methods

Results

Conclusion