Airway Clearance Needs in Neuromuscular Disease: An Overview

Because NMD generally affects the respiratory muscles, most of these patients suffer from restrictive lung disease (RLD). The restrictive component tends to be especially severe in amyotrophic lateral sclerosis, Duchenne’s muscular dystrophy, and spinal muscular atrophy types I and II.8 Even in the earliest stages of these diseases, when few if any respiratory symptoms have been reported, pulmonary function tests (PFTs) may be abnormal. In evaluating patients with early-stage NMD, Demedts et al found an average vital capacity of 75% of predicted norm, as well as a reduction in maximal transpulmonary and transrespiratory pressures.9