Spinal Muscular Atrophy
Spinal muscular atrophies (SMA) are a group of inheritable neurodegenerative disorders that vary greatly in terms of severity and prognosis. The SMAs conditions are characterized by progressive neuromuscular weakness, spinal deformity, frequent, severe respiratory infections and, ultimately, death following respiratory failure. Intellectual development, as well as sensory function, are not affected. Several distinct types of SMA are classified by degree of neuromuscular impairment and age at diagnosis. The condition occurs in approximately one newborn in 6,000. Although SMA is incurable, it is increasingly treatable. With aggressive disease management including effective airway clearance therapy and assisted ventilation, longer-term survival is steadily increasing.
Children with SMA have an increased risk of recurrent pneumonia from impaired airway clearance. Cough and pulmonary defenses diminish progressively as thoracic skeletal deformity worsens and respiratory and swallowing muscles weaken. Increased risk for aspiration and reduced ability to clear airway secretions ensues, leading to increasing frequent and severe respiratory infections and pneumonias.
Many physicians prescribe vest therapy for SMA patients who cannot mobilize airway secretions without therapy. Methods requiring a lot of effort on the part of the patient are generally unsuitable. In patients with ineffective cough, additional techniques or devices to clear secretions from central airways are also required.