Congenital central hypoventilation syndrome (CCHS) is a rare condition characterized by dysfunction of automatic control of breathing, most dramatically during sleep, and was first described by Mellins et al in 1970. The term Ondine’s curse was originally used to describe this syndrome, based on a literary reference to the unfaithful husband of the daughter of Poseidon, but is now largely out of favor. At present there are a few hundred known cases worldwide. The estimated incidence varies widely in different reports, from 1 in 10,000 to 1 in 200,000 live births. The clinical manifestations of CCHS appear to be related to a spectrum of neural crest disorders. Between 15% and 20% of patients have aganglionic megacolon (Hirschsprung disease [HD]), and 2 to 5% acquire neural crest tumors such as neuroblastoma, [...]
The phenomenon of nocturnal hypoxemia complicating COPD has been recognized for at least 50 years. It has also long been recognized that, in comparison to their nonhypoxemic brethren, hypoxemic COPD patients have greater degrees of pulmonary hypertension and cor pulmonale, require more frequent hospitalizations, and sustain higher mortality rates. Not surprisingly, sleep-related hypoxemia in the COPD patient is most frequently associated with awake oxyhemoglobin desaturation and diurnal hypercapnia, both of which may be quite modest in degree; and individuals who are already significantly hypoxemic while awake are more likely to exhibit profound desaturation during sleep. In one study, all patients with diurnal oxyhemoglobin saturations 95% were hypoxemic at night; another study found a high correlation between diurnal PaC02 > 50 mm Hg and nocturnal hypoxemia.