Sleep disorders in neuromuscular diseases.

This article reports the results of several studies on neuromuscular patients (9 Duchenne's muscular dystrophy, 10 myotonic muscular dystrophy, 8 mitochondrial myopathies, 6 spinal muscular atrophy). An evaluation of respiratory function during wakefulness, a sleep questionnaire and an overnight polysomnography were performed in all patients. Recurrent hypoxaemia of variable degree was observed during sleep. In most cases, night-time hypoxaemia appears not to be predictable during wakefulness. Nocturnal hypoxaemia occurs in relation to apnoeas or hypopnoeas, mainly of central type, especially when these breathing irregularities occur during rapid eye movement (REM) sleep. Moreover, polygraphic sleep-apnoea patterns, as defined by international criteria, seem to be an infrequent condition, except for those neuromuscular diseases, characterized by an involvement of the central nervous system.