Central alveolar hypoventilation in neurosarcoidosis

Although the lung is almost always involved in sarcoidosis and respiratory failure is not uncommonly caused by intrinsic lung disease, chronic alveolar hypoventilation on the basis of neurosarcoidosis has not been previously described. This report describes the case of a 42-year-old woman with sarcoidosis and documented involvement of the lungs, muscle, peripheral nerves, and skin. She presented with ventilatory failure and a vital capacity of 700mL and required hospitalization for intubation and mechanical ventilation. After failing ventilator weaning attempts and requiring continuous ventilatory assistance, she was extubated to continuous use of noninvasive intermittent positive pressure ventilation (IPPV). She eventually weaned to nocturnal-only use of noninvasive IPPV. However, her PaCO₂ remained elevated during daytime hours despite the fact that her vital capacity had returned to 3,600mL. She was not obese, and her oxyhemoglobin saturation (SaO₂) was normal on room air. Subsequent attempts to discontinue nocturnal nasal IPPV resulted in marked nocturnal decreases in SaO₂ and return of symptoms. This case illustrates successful noninvasive management of an apparently unique occurrence of central alveolar hypoventilation caused by neurosarcoidosis.