Abnormal respiration and sudden death during sleep in multiple system atrophy with autonomic failure.

We studied respiration during sleep in 7 patients with multiple system atrophy and autonomic failure (MSA-AF) and 7 control subjects. Although mean respiratory rate, tidal volume, and inspiratory flow rate were statistically similar in both groups, the coefficients of variability in all were significantly greater in MSA-AF patients. Four of 5 nontracheostomized had evidence of upper airway obstruction without significant oxygen desaturation. Three of these 5 patients died suddenly during sleep. MSA-AF is associated with upper airway dysfunction and disordered central respirations which can be life threatening. Evidence of even mild obstruction during sleep should warrant tracheostomy.