Sleep apnea syndrome in a patient with Shy-Drager syndrome.

A patient with autonomic insufficiency and extrapyramidal signs (Shy-Drager syndrome) and sleep apnea syndrome (SAS) underwent hemodynamic studies. In comparison to patients with SAS and intact autonomic reflexes, systemic hypertension was absent and marked sinus arrhythmia during sleep was blunted. Cyclical pulmonary hypertension associated with frequent apneic episodes during sleep persisted, reflecting a minor role of autonomic reflexes in the generation of this abnormality. Autopsy confirmed the Shy-Drager syndrome and multiple areas of degeneration were observed in areas of the CNS outside the medullary respiratory centers, suggesting their importance in the origin of the respiratory abnormalities in SAS.