[Isolated respiratory insufficiency in Arnold-Chiari malformation].

We report on a 45-year old woman with daytime sleepiness, polycythemia, hypoxemia and hypercapnia, admitted to hospital on three occasions in a 10 month period for acute respiratory failure. Polysomnography demonstrated apneas of central type, testing of the respiratory drive suggested central alveolar hypoventilation and magnetic resonance imaging showed an Arnold-Chiari malformation with syringomyelia. The originality of this case is the absence of any neurologic sign, respiratory failure being the sole manifestation of the Arnold-Chiari malformation.