Sleep and Stroke: New Updates on Epidemiology, Pathophysiology, Assessment, and Treatment

Sleep disorders as both risk factors for, and a consequence of, stroke: A narrative review

BACKGROUND AND PURPOSE

Sleep disorders are increasingly implicated as risk factors for stroke, as well as a determinant of stroke outcome. They can also occur secondary to the stroke itself. In this review, we describe the variety of different sleep disorders associated with stroke and analyze their effect on stroke risk and outcome.

METHODS

A search term-based literature review ("sleep," "insomnia," "narcolepsy," "restless legs syndrome," "periodic limb movements during sleep," "excessive daytime sleepiness" AND "stroke" OR "cerebrovascular" in PubMed; "stroke" and "sleep" in ClinicalTrials.gov) was performed. English articles from 1990 to March 2023 were considered.

RESULTS

Increasing evidence suggests that sleep disorders are risk factors for stroke. In addition, sleep disturbance has been reported in half of all stroke sufferers; specifically, an increase is not only sleep-related breathing disorders but also periodic limb movements during sleep, narcolepsy, rapid eye movement (REM) sleep behavior disorder, insomnia, sleep duration, and circadian rhythm sleep-wake disorders. Poststroke sleep disturbance has been associated with worse outcome.

CONCLUSION

Sleep disorders are risk factors for stroke and associated with worse stroke outcome. They are also a common consequence of stroke. Recent guidelines suggest screening for sleep disorders after stroke. It is possible that treatment of sleep disorders could both reduce stroke risk and improve stroke outcome, although further data from clinical trials are required.

Efficacy and safety of acupuncture in the treatment of stroke complicated with sleep apnea syndrome: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

stroke patients often have a combination of sleep apnea syndrome, which is an important and modifiable risk factor for stroke prognosis. Acupuncture is one of the measures for sleep apnea syndrome, and it is also widely used in stroke. However, we are concerned that its efficacy and safety in the treatment of stroke with sleep apnea syndrome are not yet clear.

METHODS

This systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses schema and was registered with INPLASY (registration number: INPLASY202250113). The following 8 databases were searched: PubMed, Cochrane Library (CENTRAL), Embase, Web of Science, China National Knowledge Infrastructure, Chongqing VIP Information, WanFang Data, and China Biomedical Literature Database limited from the establishment of each database to May 4, 2022. Subject headings, free words, and keywords were used for retrieval. Relevant literature was supplemented by consulting other resources. We assessed the risk of bias in the included studies using the Cochrane risk of bias tool. RevMan 5.4 software (The Cochrane Collaboration, 2020) was used to perform the meta-analysis.

RESULTS

Six records were included, including a total of 513 participants: 256 in the experimental group and 257 in the control group. The results showed that the total effective rate (relative risk = 1.23, 95% confidence interval (CI): 1.13, 1.34, P < .00001), apnea-hypopnea index (mean difference (MD) = -8.39, 95% CI: -9.19, -7.59, P < .00001), Epworth Sleepiness Scale score (MD = -1.59, 95% CI: -2.66, -0.52, P = .004), minimal oxygen saturation (MD = 4.99, 95% CI: 3.5, 6.47, P < .00001), longest duration of apnea (MD = -7.47, 95% CI: -8.97, -5.97, P < .00001), longest duration of apnea (MD = -6.48, 95% CI: -8.60, -4.35, P < .00001), and S100β levels (standard mean difference = -1.52, 95% CI: -1.87, -1.18, P < .00001) were better in the experimental group than in the control group. Simultaneously, the effect of reducing the neuron-specific enolase level in the experimental group was comparable to that in the control group (MD = -3.40, 95% CI: -9.08, 2.29, P = .24).

CONCLUSIONS

Acupuncture can improve the clinical symptoms and related laboratory indicators for sleep apnea syndrome in patients with stroke. More high-quality trials remain urgently needed.

Post-stroke sleep disturbance and recurrent cardiovascular and cerebrovascular events: A systematic review and meta-analysis

Despite improvements in survival rates, risk of recurrent events following stroke remains high. Identifying intervention targets to reduce secondary cardiovascular risk in stroke survivors is a priority. The relationship between sleep and stroke is complex: sleep disturbances are likely both a contributor to, and consequence of, stroke. The current aim was to examine the association between sleep disturbance and recurrent major acute coronary events or all-cause mortality in the post-stroke population. Thirty-two studies were identified, including 22 observational studies and 10 randomized clinical trials (RCTs). Identified studies included the following as predictors of post-stroke recurrent events: obstructive sleep apnea (OSA, n = 15 studies), treatment of OSA with positive airway pressure (PAP, n = 13 studies), sleep quality and/or insomnia (n = 3 studies), sleep duration (n = 1 study), polysomnographic sleep/sleep architecture metrics (n = 1 study), and restless legs syndrome (n = 1 study). A positive relationship of OSA and/or OSA severity with recurrent events/mortality was seen. Findings on PAP treatment for OSA were mixed. Positive findings indicating a benefit of PAP for post-stroke risk came largely from observational studies (pooled RR [95% CI] for association between PAP and recurrent cardiovascular event: 0.37 [0.17-0.79], I2 = 0%). Negative findings came largely from RCTs (RR [95% CI] for association between PAP and recurrent cardiovascular event + death: 0.70 [0.43-1.13], I2 = 30%). From the limited number of studies conducted to date, insomnia symptoms/poor sleep quality and long sleep duration were associated with increased risk. Sleep, a modifiable behavior, may be a secondary prevention target to reduce the risk of recurrent event and death following stroke. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021266558.

Relationship of sleep duration with the risk of stroke incidence and stroke mortality: an updated systematic review and dose-response meta-analysis of prospective cohort studies

BACKGROUND

The relationship between inappropriate sleep duration with stroke incidence and mortality remains controversial. We carried out dose-response meta-analysis to quantify their dose-response relationships.

METHODS

We systematically searched and extracted data from prospective cohort studies regarding sleep duration and stroke published on PubMed, EMBASE, Cochrane Library, CNKI, and Wangfang Data until October 20, 2020. We used Stata version 15.0 for meta-analysis and dose-response meta-analysis.

RESULTS

A total of 20 articles including 27 reports were included. There had fifteen and 12 reports concerning sleep duration and stroke incidence and stroke mortality respectively. Meta-analysis showed that short sleep was linked to an increased risk of stroke incidence and stroke mortality (RR: 1.33, 95% CI: 1.19-1.49 and RR: 1.37, 95% CI: 1.16-1.62 respectively). Long sleep was also associated with an increased risk of stroke incidence and stroke-related death (RR: 1.71, 95% CI: 1.50-1.95 and RR: 2.41, 95% CI: 1.87-3.09, respectively). Dose-response meta-analysis demonstrated that U-shaped relationship was observed between sleep duration and risk of all outcomes. Sleep duration presented a nonlinear relationship with stroke incidence, stroke mortality, ischemic stroke, female stroke and male stroke. Prolonged sleep was associated with an increased risk of hemorrhagic stroke and male stroke.

CONCLUSIONS

Our findings indicate that both short and long sleep duration was linked to a higher risk of stroke incidence and stroke mortality. Extended sleep duration was more associated with adverse outcomes compared with short sleep duration. Inappropriate sleep duration correlated more with ischemic stroke and an increased risk of stroke in females.

Obstructive sleep apnea, cpap and COVID-19: a brief review

Obstructive sleep apnea (OSA) is a broadly diffused curable chronic low-grade inflammatory disease sharing impressive clinical and pathogenetic features with Covid-19. Moreover, a potential role of OSA as a detrimental factor for Covid-19 severity has been hypothesized. Continuous positive airway pressure (CPAP) is the mainstay treatment for moderate-severe OSA, but the beneficial effects of ventilation strongly depend on medical expertise and on the patient's adherence and compliance. Although several papers have analyzed the overlaps and outcomes of OSA and Covid-19, limited attention has been dedicated to ventilatory adherence and management of  OSA cohorts exposed to Covid-19. We briefly review the literature data, pointing out the main risks and benefits of CPAP for OSA patients in the pandemic setting.