Effect of Neuromuscular Electrical Stimulation (NMES) on swallowing in Persons with Parkinson’s disease exhibiting Dysphagia: A Systematic Review

Swallowing is an essential activity required for survival. The global definition of dysphagia is simply difficulty in swallowing. Around 80% of individuals with Parkinson’s disease (PD) are diagnosed with dysphagia in any stage of their disease progression. Dysphagia therapy in these individuals has gained considerable importance in improving the quality of life in the recent past. With the advancement of technology related to dysphagia management, the use of Neuromuscular Electrical Stimulation (NMES) in dysphagia management is studied extensively, and the efficacy of it in successfully easing dysphagia symptoms in PD is still being evaluated. Hence this systematic review is aimed to give an overview regarding the current status of the literature available on the effect of NMES as a method of dysphagia rehabilitation on swallowing function in persons with PD. The present review will collate and critically analyse the existing knowledge of neuromuscular electrical stimulation in dysphagia management of persons with Parkinson’s disease. The authors did a systematic literature search following the PRISMA guidelines using electronic databases for studies reporting the use or effect of NMES on swallow function, aiding management of dysphagia in persons with PD. The quality and the levels of evidence of articles included were in accordance with the ABC rating scale by Siwek et al [20]. 3 out of 38 publications identified met the inclusion criteria. The authors carried out a systematic, qualitative and critical analysis of the articles finalised. The summary of the reviewed articles revealed the dearth of evidence and several methodological flaws as well as highlighted the prevailing research gap in this arena. This review additionally aids Speech-Language and Swallow Pathologists in clinical decision making and future directions concerning selecting Neuromuscular Electrical Stimulation (NMES) as a treatment option for managing dysphagia in persons with PD.