Contribution of Diaphragmatic Ultrasound for Monitoring Diaphragmatic Function in Patients With Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a rare neuromuscular disease that occurs in adults. It is characterized by a progressive degeneration of the first and second motor neurons leading to muscle failure. In its spinal form, ALS manifests by a progressive worsening of limb involvement, whereas the bulbar form presents with swallowing disorders, dysarthria and feeding difficulties. Respiratory impairment is the most serious feature of ALS. Phrenic nerve damage causes diaphragmatic weakness, which inevitably leads to chronic restrictive respiratory failure. At the stage of symptomatic nocturnal or diurnal alveolar hypoventilation, non-invasive ventilation (NIV) prolongs survival while improving quality of life by relieving respiratory symptoms. The indication for the initiation of NIV is based on the appearance of respiratory symptoms but also on the demonstration of diaphragmatic insuf