The Impact of Nusinersen Treatment on Respiratory Function in Patients with Spinal Muscular Atrophy: A Systematic...

Background/Objectives: This systematic review evaluated the impact of nusinersen therapy on respiratory health and function in individuals with spinal muscular atrophy (SMA) and determined whether nusinersen improves pulmonary function, focusing on differences based on patient age and the timing of treatment initiation. Methods: A systematic search of PubMed, Ovid Medline, ScienceDirect, and Web of Science databases was conducted up to January 2024 in accordance with the PRISMA guidelines. Thirteen studies were included, comprising clinical trials, observational studies, and case series that focused on respiratory outcomes in SMA patients treated with nusinersen. The data on study design, participant characteristics, nusinersen intervention, respiratory outcomes, and adverse events were extracted. The Joanna Briggs Institute Critical Appraisal Tool was used to assess study quality. A narrative synthesis was conducted to address the heterogeneity of the studies. Results: This review found a general trend of improvement in pulmonary function, specifically in forced vital capacity (FVC), although the extent and duration of improvement varied across the studies. Peak cough flow (PCF) and peak expiratory flow (PEF) showed positive trends in some studies, although the results were not consistently significant. Respiratory function improvements were frequently observed, particularly in younger patients and those treated earlier. Conclusions: Nusinersen appears to enhance respiratory function and improve motor outcomes in SMA patients, especially with early treatment. However, further research is needed to fully understand its mechanisms and long-term effects on respiratory health in SMA.