Arnold-Chiari malformation and paralysis of the diaphragm.

A woman aged 17 years presented with symptoms of somnolence. A bilateral diaphragmatic paralysis and an Arnold-Chiari malformation were diagnosed. Lung function tests revealed a marked restrictive defect and a blunted ventilatory response to hypercapnia and hypoxia. A sleep study also showed central apneas, an irregular pattern of breathing and marked hypoventilation.