[Sleep disorders as a risk factors for stroke]

Sleep-disordered breathing seems to play a role in pathogenesis of stroke: for example, it was showed that snoring is a risk factor for stroke. Sleep disorders and sleep-disordered breathing increase the risk for stroke, probably by influencing systemic and cerebral blood circulation, causing hypoxaemia during night. This theory is supported by the fact of higher prevalence of stroke in the morning. During REM sleep there is a higher requirement for oxygen; as most sleep apnoeas occur during REM, it is possible that there is a relative hypoxaemia during this sleep stage. Stroke, including hemispheric stroke, can cause or aggravate the pre-existing sleep-disordered breathing. There are contradictory data in the literature regarding the influence of stroke on sleep architecture. Sleep disorders are associated with poorer stroke outcome, so their detection and treatment can be important in secondary stroke prophylaxis and will improve the patient's functioning and quality of life.