The relationship between sleep disorders and stroke.

Although sleep appears to be a quiescent, passive state externally, there are a multitude of physiological changes occurring during sleep that can affect cerebral homeostasis and predispose individuals to cerebrovascular disorders. Therefore, it is not surprising that sleep-disordered breathing causes significant nocturnal perturbations, such as obstructive sleep apnea (OSA), that can lead to cerebrovascular disorders. There is evidence to suggest that OSA is a risk factor for stroke, although studies have not been able to clearly discern the absence or presence of OSA before the stroke event. Sleep-disordered breathing, such as OSA and central sleep apnea, can occur as a consequence of stroke. Fortunately, treating OSA appears to decrease morbidity and possibly mortality. Unfortunately, continuous positive airway pressure compliance in this population group is low, and significant efforts and resources may be needed to improve compliance and adherence. Various other sleep disorders, such as insomnia, fatigue, hypersomnia, and parasomnia, can occur following a stroke, and physicians treating patients following a stroke need to be aware of these disorders in order to effectively treat such patients.