Stroke and Sleep Disorders

Sleep disorders are highly prevalent in patients at risk for stroke and may be modifiable risk factors for stroke. Obstructive sleep apnea increases the risk of stroke independently, but the reported lack of therapeutic effectiveness of Continuous positive airway pressure for stroke prevention and cardiovascular protection should be cautiously interpreted. Short or long sleep duration, and insomnia with objective short sleep duration, could be risk factors for stroke and mortality. Sleep-related movement disorders, including Periodic limb movement during sleep and Restless leg syndrome are also potential risk factors for stroke. The overall findings suggest that systematic screening and proper management of sleep disturbances can substantially contribute to stroke risk modification at the population level. Examines Phy Med Rehab Copyright © Mehmet Murat Sumer 2/4 How to cite this article: Mehmet M S. Stroke and Sleep Disorders. Examines Phy Med Rehab. 2(1). EPMR.000526. 2018. DOI: 10.31031/EPMR.2018. 02.000526 Volume 2 Issue 1 a stronger effect than OSA, not mitigated by CPAP therapy. OSA is also associated with the risk for cardio embolism. People with OSA have four times the odds of atrial fibrillation [32]. Nocturnal oxygen desaturation is an independent risk factor for new onset atrial fibrillation [33]. Sleep apnea is associated with inflammation, endothelial dysfunction, hypercoagulability, and cerebral hemodynamic changes [34-41]. Recent studies reported that OSA was significantly associated with incident stroke [42]. The relationship between sleep duration and stroke incidence is U-shaped in general; the risk for stroke is elevated in both short and long sleep groups [4345]. Short sleep, commonly defined as <5 to 6 hours of nocturnal sleep, increases the risks of stroke, coronary heart disease, and death [44,46]. Sleep deprivation leads to increased levels of the appetite stimulating hormone ghrelin and reduced levels of the anti-appetite hormone leptin [47]. Furthermore, reduced physical activity associated with sleep deprivation leads to weight gain by decreasing energy expenditure [48]. Short sleep is also associated with sympathetic overactivity, which leads to impaired glucose metabolism hypertension, and non-dipping of blood pressure [49-51]. Long sleep duration (more than 9 hours of sleep) is also associated with stroke and cardiovascular mortality [52]. The linking mechanisms between long sleep and stroke are still elusive, but increased inflammation and abnormal lipid profiles in long sleepers have recently been reported [53,54]. Insomnia is prevalent in approximately 10% to 20% of the adult population, with approximately 50% having a chronic form. Chronic insomnia disorder is characterized by a complaint of difficulty initiating sleep and maintaining sleep and waking up earlier than desired. The diagnosis of chronic insomnia requires occurrences on at least three nights per week for at least 3 months. Insomnia was found to be a risk factor for cardiovascular events and death [55]. Elevated sympathetic and hypothalamic-pituitaryadrenal axis activity has been proposed as a mechanism for the cardiovascular effect of insomnia [8]. The defining feature of PLMS is periodic episodes of repetitive, highly stereotyped limb movements during sleep, which mostly occur in the lower extremities and can be associated with cortical arousal. A positive relationship between PLM and cardiovascular events or mortality has been demonstrated in observational studies, and a greater risk attributed to PLM combined with arousals [56,57]. PLM with arousal induces an abrupt increase in blood pressure and heart rate through sympathetic overshoot. Sympathetic overactivity, metabolic dysregulation, inflammation, oxidative stress, peripheral hypoxia, and hypothalamic pituitaryadrenal activation have been proposed as possible linking mechanisms between PLM/RLS (Restless leg syndrome) and cardiovascular diseases [58]. Repeated nocturnal fluctuations in heart rate and blood pressure that are associated with PLM and related microarousals cause daytime hypertension, subsequently increasing the risk for cerebrovascular diseases [58,59]. References 1. Lozano R, Naghavi M, Foreman K, Lim S, Shibuya K, et al. (2012) Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: A systematic analysis for the global burden of disease study 2010. Lancet 380(9859): 2095-2128. 2. Feigin VL, Forouzanfar MH, Krishnamurthi R, Mensah GA, Connor M, et al. (2014) Global and regional burden of stroke during 1990-2010: Findings from the global burden of disease study 2010. Lancet 383(9913): 245-254. 3. 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