The breathing patterns and HbSaO2 changes during nocturnal sleep were monitored in 11 chair-bound Duchenne muscular dystrophy patients at the Institutes of Neurology and Respiratory Diseases, University of Pavia, Italy. Nocturnal sleep had no significant adverse effects on the nighttime polygraphic sleep recordings and respiration. Infrequent central apneas occurring in six patients were associated with falls in HbSaO2. greater than normal and correlated with functional residual capacity values. The blood oxygen balance was relatively preserved but unstable during nocturnal non-REM and REM sleep in patients with Duchenne muscular dystrophy, mean age 15 years (range 10-21) even in advanced stages of the illness. 
COMMENT. Acute respiratory failure is an important factor contributing to death in most patients with Duchenne muscular dystrophy. During the later stages of the illness, a restrictive lung disease related to the progressive inspiratory muscle weakness and rib cage deformities develops. In this study, nocturnal sleep did not seem to have a significant adverse effect on respiration and no pathological breathing patterns were observed. Unimpaired diaphragmatic function might account for the relatively preserved arterial oxyhemoglobin desaturation during REM sleep in the population studied.