Pathophsyiological role of sleep in diaphragm paralysis and neuromuscular disorders

Respiration and the regulation of respiration are changing with the onset of sleep. Additionally, muscle activity of the diaphragm and the extradiaphragmatic respiratory muscles varies during different sleep stages. Nonetheless respiration during sleep remains stable in healthy subjects. In patients with ventilatory insufficiency caused by uni- or bilateral diaphragm paralysis or other neuromuscular diseases respiration is most vulnerable during sleep. Hence, sleep disordered breathing is frequently seen in early stages of these diseases. Simple lung function studies like spirometry in upright and supine position can provide first evidence towards the presence of sleep disordered breathing. Only later during the course of the diseases patients will present with symptoms of disturbed sleep and ventilatory insufficiency. Goal of the care in patients with diaphragmatic paralysis and neuromuscular disorders must be to diagnose sleep-related breathing disorders early on and to initiate appropriate therapy in the form of non-invasive ventilation in order to improve quality of life and prognosis of these patients.