[Primary alveolar hypoventilation. Clinical aspects and diagnostic problems. Apropos of a case].

Primary alveolar hypoventilation is a rare syndrome of unknown origin, characterized by a dysfunction of the automatic respiratory pattern in spite of normal lungs and in the absence of mechanical ventilatory defects. A reduction of the ventilatory response to CO2 is regularly found, and cardiac failure is common. The differential diagnosis mainly concerns the sleep apnoea syndrome. The usual treatments have little effectiveness.