Sleep-disordered breathing in patients with Chiari malformation: improvement after surgery.

Sixteen consecutive patients with Arnold-Chiari malformation type I and syringomyelia underwent full-night polysomnography (PSG). Sleep apnea syndrome (apnea-hypopnea index > 10) was diagnosed in 12 of 16 patients with 48% of central apneas. In six patients with sleep apnea syndrome, PSG was repeated an average of 203 days after decompression surgery. Postoperative PSG showed a decrease in the central apnea index from 14.9 +/- 5.5 to 1.3 +/- 0.6 (p = 0.03).