Nocturnal arterial oxygen desaturation secondary to a sphenoidal meningioma.

We report the case of a nonobese and nonsmoking 51-year-old man with nocturnal arterial oxygen desaturation that returned to normal after sphenoidal meningioma resection. He presented an important daytime hypersomnia and episodes of nocturnal apnea, without snoring. His arterial blood gases, mechanical properties of the respiratory system pulmonary diffusing capacity and chemosensitivity were normal. The most frequent causes of nocturnal hypoxemia are examined.