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Risk factors of sleep disorder after stroke

J Sleep Disord Ther 3: This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

In this review, we will discuss the risk factors of sleep disorder after stroke supporting OSA not only a risk factor for stroke, but also show how untreated OSA has been associated with worse outcomes in those who suffer from stroke and OSA. Abstract Obstructive sleep apnea OSA has been associated with many of the known risk factors for stroke including hypertension, diabetes and atrial fibrillation.

There is also a large body of literature that suggests that OSA and stroke are independently associated. Both have been described in stroke, though OSA is more prevalent and seems to have more impact on stroke outcomes. The prevalence of SDB is higher among stroke patients than the average population.

Central apneas appear to be more common acutely after a stroke and then decrease by three months [ 2 ]. While there is a growing body of evidence that OSA is associated with an increased risk for stroke, some sleep disordered breathing might also occur secondary to stroke. The brain stem is responsible for control of breathing.

A particular lesion site has not been associated with SDB in prospective studies. A recent cross-sectional study found that there was an increased prevalence of hypoglossal nerve dysfunction in patients with acute ischemic stroke. They were unable to show that the hypoglossal dysfunction was associated with more severe SDB [ 8 ]. Even though both CSA and OSA have been described in stroke, OSA is more commonly seen and is thought to have a strong association with risk for stroke as well as increased morbidity and mortality in those who have suffered from stroke.

Is OSA a risk factor for stroke? Large cross-sectional studies have shown associations between OSA and prevalent stroke with a dose response relationship according to severity of AHI [ 910 ]. However subsequently, numerous large scale observational cohorts have supported a robust association of presence of OSA and incident stroke [ 11 - 15 ].

The Busselton Sleep Cohort is the longest published cohort to date. In this 20 year prospective cohort, 393 patients who had no history of prior stroke were prospectively followed.

Moderate to severe OSA was found to have a hazard ratio of 3. There have been two recent meta-analysis conducted on prospective studies looking at Risk factors of sleep disorder after stroke as risk factor for stroke.

Until recently, the effects of OSA and its treatment on cardiovascular outcomes in women was unknown. They showed a positive association of OSA and incident stroke in men with a linear trend p-0. In women, however, incident stroke was not associated with obstructive AHI quartiles. A recent publication followed 967 women specifically for a median of 6. Does the presence of OSA affect stroke outcome? In addition to the growing support for OSA as a causal factor for stroke, there is growing evidence that co-morbid OSA may affect stroke outcomes.

The literature suggests that those who have stroke and untreated OSA have higher morbidity and mortality compared to those without OSA. Higher desaturation indices post stroke have been associated with lower functional scores on the Barthal index and higher mortality at one year [ 19 ]. This suggests that OSA may play a role with those outcomes.

Other studies have found increased mortality at one and 6 months in those with acute stroke and OSA [ 2021 ]. Similarly, Dyken et al.

OSA was found to be an independent risk factor for death after adjusting for other confounding factors such as age, sex, BMI, smoking, hypertensiondiabetes, and atrial fibrillation as well as Barthal index of daily living. OSA has also been associated with other post stroke outcomes such as length of stay, worse functional outcomes, and recurrent cerebrovascular events. It was found that presence of SBD was associated with higher risk of recurrent cerebrovascular events but interestingly, not mortality or functional outcome at 2 years [ 26 ].

The SDB group was mostly obstructive but those with central sleep apneas were included as well.

  • Until recently, the effects of OSA and its treatment on cardiovascular outcomes in women was unknown;
  • Sleep apnea linked to silent strokes, small lesions in brain February 1, 2012 People with severe sleep apnea may have an increased risk of silent strokes and small lesions in the brain, according to a small study presented at the American Stroke Association's International Stroke Conference 2012;
  • Randomized studies demonstrate CPAP intervention seems to have some short term benefit on functional recovery and recurrent vascular events but long term data supporting this is lacking;
  • A particular lesion site has not been associated with SDB in prospective studies;
  • Enhanced rehab for stroke doubles movement recovery September 27, 2018 A novel therapy technique invented by researchers at The University of Texas at Dallas has been shown in a pilot study to double the rate of upper limb recovery in stroke patients, a leap forward in treating the nearly 800,000;;;
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Perhaps including patients with CSA and very mild OSA contributed to the lack of significant difference for mortality and functional outcome. Does treatment of OSA affect stroke outcomes? The literature suggests that presence of OSA is associated with increased morbidity and mortality in those with stroke.

One should then ask, "Does treating OSA improve these outcomes? Observational trials suggest that CPAP treatment does improve mortality and decreases rate of recurrent vascular events in those with stroke and OSA compared to those stroke patients with untreated or sub optimally treated OSA.

The same group also looked at risk of recurrent vascular events. They found that at 18 months, those intolerant of CPAP had 5 fold increase risk of new vascular events odd ratio 5. Similarly, at 7 years, they found that those who risk factors of sleep disorder after stroke not tolerate CPAP had increased risk of new vascular events, particularly ischemic stroke, compared to those who tolerated CPAP [ 29 ].

Randomized controlled trials have suggested benefits of CPAP use in those with ischemic stroke and OSA in terms of functional recovery in the short term but not as robust for long term function.

The same holds true for mortality and recurrent vascular events. It is important to note, though, that the randomized trials have smaller number of subjects with shorter follow up compared to observational trials mentioned above. They showed the patients randomized to CPAP had improved scores on stroke impairment testing and motor components on functional testing compared to those not on CPAP [ 31 ].

These studies, while showing benefit for functional recovery and recurrent vascular events, have been short term with longest study being 3 months long.

Risk factors of sleep disorder after stroke: a meta-analysis.

They found neurological function was improved in the CPAP group at one month compared to control group but not at two years [ 34 ]. Survival was not statistically different between the two groups but time to next cardiovascular event was longer in the CPAP group. Conclusion The current literature supporting OSA as an independent risk factor for stroke as well as poorer outcomes in those with recent stroke is quite strong.

Observational data show a strong benefit of CPAP for recurrent vascular events and mortality that seems compelling but has not been described in randomized controlled data so far.

Sleep apnea after stroke heightens risk of another stroke; death

Randomized studies demonstrate CPAP intervention seems to have some short term benefit on functional recovery and recurrent vascular events but long term data supporting this is lacking.

The shorter duration of the randomized trials and number of subjects may play a role in the discrepancy between their results and those of observational trials. From the literature as it stands so far, it is important to screen patients with stroke for OSA and treat them appropriately as not treating them may cause the patient to incur further morbidity and mortality. However, there is recognition that large, long term, randomized trials would be helpful to further delineate the benefit of CPAP on stroke outcomes.