Neuronopathies are defined as diseases affecting the bodies of neuron cells. These disorders may be inherited, sporadic or acquired and may be observed in children or adults. Spinal muscular atrophies, amyotrophic lateral sclerosis and Post-polio syndrome are prototype disorders in this group. The clinical course, time for diagnosis and therapeutic processes are very compelling for the patients, their relatives and physicians. Disturbances in sleep structure, an increase in cyclic alternating pattern and sleep-related disorders, especially of sleep-related breathing disorders, are commonly reported in these patients. More importantly, changes in sleep microstructure and associated sleep-related disorders have a negative effect on the course of the neuronopathies. By contrast, beneficial outcomes on the clinical course and prognosis of neuronopathies have been reported upon the diagnosis and treatment of sleep-related disorders early in the disease course. For these reasons, investigating and treating deteriorations in the microstructure of sleep and sleep-related disorders in patients with spinal muscular atrophies, amyotrophic lateral sclerosis or Post-polio syndrome are important.