Effect of nusinersen on respiratory function in patients with spinal muscular atrophy: an 18-month single-center prospective study.

Background: Spinal muscular atrophy (SMA) is a severe neuromuscular disease characterized by respiratory muscle weakness, often leading to high mortality. Research on the effect of nusinersen on respiratory function in SMA patients remains scarce. Objective: To evaluate nusinersen's effect on respiratory function in SMA patients and provide a clinical basis for respiratory management. Methods: In this single-center prospective study, clinical data were collected from SMA patients in our pediatric department. Respiratory function, expressed as absolute values and percentages of predicted values (%pred), and active cough strength was evaluated at baseline and during follow-up after nusinersen treatment. Treatment effects were subsequently analyzed. Results: Among 59 SMA patients (39 Type II; 20 Type III), 40 completed baseline respiratory tests, of whom 67.5% had abnormal respiratory function. Type II patients had significantly lower VC %pred, FVC %pred, FEV1%pred, PEF %pred, FEF25%pred, and FEF50%pred than Type III patients (all Conclusion: Most SMA patients had impaired respiratory function, which was more severe in Type II than Type III patients. Nusinersen improved respiratory function and active cough strength, but could not fully reverse the progression of restrictive ventilatory dysfunction, especially in Type II.