Effect of sleep apnea on cognition and mood.

Obstructive sleep apnea syndrome (OSAS) is a common disorder in adults and children, which is characterized by repetitive transient reversible upper airway obstructions during sleep. Due to disrupted sleep architecture and intermittent hypoxemia, OSAS leads to impaired daytime functioning in various neuropsychological and affective domains. The most common abnormalities are executive dysfunction, impaired vigilance, depression, and possibly anxiety and, in children, hyperactivity. Optimal treatment of OSAS with continuous positive airway pressure may reverse the cognitive and affective dysfunction, however, in some patients a residual impairment persists. This persistent deficit, despite effective treatment, raises the possibility of a remaining subtle structural brain damage; such damage has been demonstrated through the use of sensitive functional and other neuroimaging techniques. Prefrontal cortical damage may underlie the cognitive dysfunction in OSAS. Early recognition and treatment may prevent this untoward effect of OSAS.