Exploring Factors and Nonpharmacological Interventions Associated With Respiratory Function in People With Multiple Sclerosis: A Scoping Review

Background: Multiple sclerosis (MS) can impair respiratory function due to demyelinating lesions that disrupt neural input to respiratory muscles. This dysfunction may result in muscular weakness, ineffective coughing, and respiratory failure. Early identification and management of respiratory dysfunction can improve long-term outcomes and reduce morbidity and mortality. Factors contributing to early respiratory decline in MS are understudied. This review aims to characterize factors associated with and nonpharmacological interventions for respiratory dysfunction in people with MS.

Methods: This review was registered with the Open Science Framework and conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. A comprehensive search of PubMed, Embase, and Scopus was conducted for articles published in English between 2014 and 2024. Eligible studies assessed respiratory function and evaluated nonpharmacological interventions or associated factors. Peer-reviewed observational and experimental studies were included. Titles, abstracts, and full texts were screened independently by 2 reviewers using Covidence.

Results: Findings from 11 observational studies identified factors that influence respiratory function, including disease-related, physical, and psychological factors. Nine studies investigated nonpharmacological interventions such as inspiratory/expiratory muscle training, Pilates, lung volume recruitment, and proprioceptive neuromuscular facilitation; all showed improvements in respiratory outcomes.

Conclusions: Although the impact of physiological, functional, psychological, and psychosocial factors has been studied in relation to respiratory dysfunction in MS, other increasingly common factors in MS, such as obesity, have not been studied and warrant further investigation. Nonpharmacological therapies show promise in improving respiratory function in people with MS, but larger trials with longer-duration interventions are needed to confirm the efficacy of these interventions.