Severe adult hypersomnia--sleep apnea syndrome in craniofacial dysostosis.

Polysomnography and blood gas measurements during sleep in a young man with craniofacial dysostosis, who presented with an extremely severe sleep apnea syndrome, are reported. Tracheostomy relieved all his complaints permanently, namely hypersomnia, deteriorated intellectual performance, automatic behaviour with hypnagogic hallucinations and snoring. Laboratory results also returned to normal. The polygraphic data of night sleep (and daytime naps) before and after surgery suggest that hypersomnia was primarily caused by severe nighttime oxygen desaturations and that the hypnagogic hallucinations were caused by apnea-induced chronic REM sleep deprivation. Furthermore, the periodic variation of central respiratory drive, which was also abolished after surgery, is interpreted as the cause of apnea-induced fluctuations between sleep stages in this case.