Sleep disorders in patients with neuromuscular diseases

Neuromuscular diseases (NMD) may affect skeletal muscles, peripheral nerves, or motor endplates. Clinical symptoms comprise muscle weakness, which is often progressive, but also sensory disturbances, and primary or secondary pain. Sleep disturbances in NMD may result from insomnia due to immobility, pain, or sleep-related leg muscle cramps, but also restless legs syndrome and sleep-disordered breathing. Many NMD predispose to obstructive sleep apnea or progressive respiratory muscle weakness, which first manifests as sleep-related hypoventilation and eventually leads to chronic hypercapnic respiratory failure. The latter is crucial for overall prognosis in muscular dystrophies and myopathies, but even more so in motor neuron diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy.