Diaphragm ultrasonography in amyotrophic lateral sclerosis: a diagnostic tool to assess ventilatory dysfunction and disease severity

Background Respiratory failure represents an unavoidable step in patients with amyotrophic lateral sclerosis (ALS) and other motor neuron diseases (MND). The development of diaphragm ultrasonography (DUS) provides an alternative useful and risk-free tool to supply clinical, functional, and neurophysiological assessment of respiratory muscle weakness. Our aim was to evaluate if sonographic changes (thickness and echogenicity in the costal portion of the diaphragm, at rest and during respiratory movements) may be used in ALS patients to assess disease severity over time, to rule out any risk or discomfort due to traditional neurophysiological investigations.