Multiple system atrophy presenting with acute respiratory failure due to diaphragmatic dysfunction.

Sleep related respiratory dysfunction and vocal cord paralysis are considered to be the major factors responsible for respiratory failure in multiple system atrophy (MSA). We report a patient initially presenting with alveolar hypoventilation culminating in respiratory failure, ultimately diagnosed as MSA. No central sleep apnea or marked paralysis of the vocal cords was noted. The most likely cause for the respiratory failure was thought to be the weakness of respiratory musculature. This case emphasizes the need that MSA should be added to the differential diagnosis of unexplained hypercapnic respiratory failure.