Pulmonary Function Test Changes and Respiratory Muscle Strength Trends in Spinal Muscular Atrophy Patients Receiving Nusinersen Treatments

It is well known that patients with spinal muscular atrophy (SMA) have progressive decline of respiratory muscle function. Therapy traditionally involved supportive means to ensure optimal nutrition and airway clearance. Nusinersen (spinraza) is a disease-modifying medication approved for treatment of SMA in pediatric and adult patients. The goal of this study is to observe pulmonary function test (PFT) changes and respiratory muscle strength trends throughout the first year of treatment. A prospective, longitudinal study measuring pulmonary function testing (PFTs) changes in spinal muscular atrophy (SMA) patients. Patients will be patients with SMA who are approved and maintained on nusinersen. Patient will have a baseline PFT. Investigators will repeat PFT at 3, 6, and 12 months while on nusinersen treatment.