Neuromuscular electrical stimulation in conjunction with conventional swallowing therapy in the treatment of dysphagia caused by Multiple sclerosis: A single case experimental design

Introduction: Dysphagia as a consequence of Multiple Sclerosis (MS) puts individuals at higher risk of dehydration, malnutrition, and aspiration pneumonia. This study intended to investigate the effects of a combined program of neuromuscular electrical stimulation (NMES) and conventional swallowing therapy to improve swallow safety and efficiency, oral intake, and physical, emotional and functional impacts of dysphagia in people with dysphagia and MS. Methods: In this single case experimental study with ABA design, two participants with dysphagia caused by MS underwent 12 sessions therapy during 6 weeks following a baseline of 4 evaluation sessions. They were evaluated 4 more times in the follow-up phase after therapy sessions. Scores of Mann Assessment of Swallowing Ability (MASA), DYsphagia in MUltiple Sclerosis (DYMUS), and timed test of swallowing capacity were obtained at baseline, during treatment, and in the follow-up phases. The Dysphagia Outcome and Severity Scale (DOSS) based on videofluoroscopic swallow studies, Persian-Dysphagia Handicap Index (Persian-DHI), and Functional Oral Intake Scale (FOIS) were also completed before and after treatment. Visual analysis and Percentage of Non-Overlapping Data (PND) were calculated. Results: MASA, DYMUS, FOIS, and DHI scores indicated significant improvement in both participants. Although the scores of the timed test of swallowing capacity in participant 1 (B.N) and DOSS in participant 2(M.A) showed no changes, considerable improvements including reducing the amount of residue and the number of swallows required to clear bolus were seen in the post-treatment videofluoroscopic records of both participants. Discussion/Conclusion: NMES in conjunction with conventional dysphagia therapy based on motor learning principles could improve the swallowing function and decrease disabling effects of dysphagia on different aspects of life in participants with dysphagia caused by MS.