Obstructive Sleep Apnea is Related to Impaired Cognitive and Functional Status after Stroke

A Review of Nursing Care for Sleep-Disordered Breathing After Stroke

ABSTRACT

BACKGROUND: Sleep-disordered breathing (SDB) occurs in 70% of stroke patients and is a risk factor for secondary stroke and poor outcomes. Discretionary nursing care provided to stroke patients with SDB is unexplored. This review examines nursing care for SDB after stroke. METHODS: We used Arksey and O'Malley's 5-stage framework. We systematically searched the PubMed and CINAHL databases through December 2023 for studies of interventions for SDB after stroke that could be implemented by nursing staff. Data on intervention characteristics, stroke and SDB types, timing, and outcomes were extracted. RESULTS: From 2866 screened articles, 10 studies met inclusion criteria. From these, we identified 5 distinct interventions: positional therapy, oropharyngeal muscle exercises, physical exercise, compression devices, and education. As confirmed by polysomnography or home sleep testing, 9 studies targeted obstructive sleep apnea. CONCLUSION: This review provides the first analysis of nurse-implementable interventions for poststroke SDB. The identified interventions appear promising for improving SDB parameters, particularly when adapted for stroke-specific care. Future research on developing standardized protocols that integrate these interventions into comprehensive care pathways will enhance the role of nurses in the early detection and management of poststroke SDB.

Early sleep apnea treatment in stroke (eSATIS) - a multicentre, randomised controlled, rater-blinded, clinical trial: The association of post-stroke cognition with sleep-disordered breathing and its treatment

Sleep-disordered breathing (SDB) is linked to cognitive dysfunction. Although SDB is common in stroke patients, the impact of SDB and its early treatment on cognitive functioning after stroke remains poorly investigated. Therefore, we explored the association between SDB and post-stroke cognitive functioning, including the impact of early SDB treatment with adaptive servo-ventilation (ASV) on cognitive recovery from acute event to 3 months post-stroke. We used data from two studies, which included ischaemic stroke patients (n = 131) and no-stroke controls (n = 37) without SDB (apnea-hypopnea index, AHI <5/h) and with SDB (AHI≥20/h). Cognitive functioning was assessed within 7 days and 3 months post-stroke in stroke patients, or at study inclusion in no-stroke control group, respectively. Stroke patients with SDB were randomized to ASV treatment (ASV+) or usual care (ASV-). Linear regression adjusted for main confounders assessed the impact of SDB and its treatment on cognitive recovery. The intention-to-treat analysis did not show significant associations of SDB ASV+ (n = 30) versus SDB ASV- (n = 29) with cognitive recovery. In an exploratory subanalysis, compliant SDB ASV+ (n = 14) versus SDB ASV- showed improvements with ASV in visual memory and cognitive flexibility. Combining the stroke and non-stroke datasets, SDB (n = 85) versus no-SDB (n = 83) was associated with deficits in visual memory and response inhibition independently of stroke. SDB ASV- versus no-SDB (n = 51) was associated with less improvement in visual memory. There was no substantial evidence for benefits of intention-to-treat ASV on cognitive recovery. Exploratory analysis indicated that compliant ASV treatment could benefit visual memory and cognitive flexibility, whereas untreated SDB could contribute to a poor recovery of visual memory.

Prevalence, Trajectory, and Factors Associated With Patient-Reported Nonmotor Outcomes After Stroke: A Systematic Review and Meta-Analysis

Importance

The evidence on nonmotor outcomes after acute ischemic stroke and intracerebral hemorrhage (ICH) is limited and domain-specific. The prevalence, natural history, and factors associated with nonmotor outcomes across multiple domains are unclear.

Objective

To synthesize the published data and to identify the prevalence, natural history, and factors associated with multidomain nonmotor outcome burden in patients with stroke.

Data Sources

A search of PubMed, MEDLINE, EMBASE, and PsycINFO databases between January 1999 to June 2023 was supplemented by search of bibliographies of the key articles.

Study Selection

The analysis included prospective cohort studies that reported nonmotor outcomes across 10 domains: anxiety, depression, fatigue, sleep disturbance, social participation, pain, bladder dysfunction, bowel dysfunction (constipation and fecal incontinence), and sexual dysfunction assessed by patient-reported scales.

Data Extraction and Synthesis

Two reviewers independently assessed studies, extracting baseline data, nonmotor prevalence, and follow-up information. Pooled prevalence of nonmotor outcomes was estimated using random-effects models. Meta-regression models were used to analyze natural history and factors associated with nonmotor outcomes. Subgroup analysis was used to assess prevalence by symptom description within each nonmotor domain. Publication bias and study quality were assessed using funnel plots and the Newcastle-Ottawa scale.

Results

A total of 279 prospective cohort studies met the inclusion criteria (117 440 participants with stroke; median [IQR] age, 65 [59-70] years; 209 of 279 studies with more male than female participants) with a nonmotor outcome follow-up period ranging from 30 days to 10 years after stroke. The most prevalent adverse nonmotor outcomes by pooled prevalence were sleep disturbance (59.9%; 95% CI, 53.9%-63.9%), sexual dysfunction (59.8%; 95% CI, 50.0%-69.5%), constipation (58.2%; 95% CI, 53.9%-62.6%), reduced social participation (56.5%; 95% CI, 52.1%-60.8%), bladder dysfunction (45.9%; 95% CI, 38.0%-53.8%), and fatigue (45.2%; 95% CI, 40.7%-49.5%). Meta-regression analysis showed no significant improvement over time for most nonmotor outcomes, except pain (coefficient = -11.0%; P = .05) and sexual dysfunction (coefficient = -24.1%; P < .001). The heterogeneity ranged between 52% and 98% across all studies. The common factors associated with adverse nonmotor outcomes were female sex, studies with mixed stroke cohort (ischemic stroke or ICH), and older age.

Conclusions and Relevance

Patient-reported nonmotor outcomes were common after stroke. Sexual dysfunction, sleep disturbance, constipation, reduced social participation, bladder dysfunction, and fatigue were most prevalent. These adverse outcomes often persisted over time, especially in women, older adults, and those in studies with mixed stroke cohorts.

Real world challenges and barriers for positive airway therapy use in acute ischemic stroke patients

PURPOSE

Untreated obstructive sleep apnea (OSA) in patients with acute ischemic stroke (AIS) is associated with increased morbidity and mortality. However, diagnosing and treating OSA in AIS is challenging. We aimed to determine the feasibility of portable monitoring (PM) for diagnosis and positive airway pressure therapy for treatment of OSA in an inpatient stroke population.

METHODS

We recruited inpatients with AIS from Cleveland Clinic. Those who consented underwent PM; participants with a respiratory event index (REI) ≥ 10 were offered auto-titrating positive airway pressure therapy (APAP). Ease-of-use questionnaires were completed. We summarized categorical variables using n(%) and continuous variables using mean ± SD or median [IQR].

RESULTS

27 participants (age 59.8 ± 11.8, 51.9% female, 51.9% Black, BMI 33.4 ± 8.5) enrolled. The study ended early due to Medicare contracting that forced most patients to complete stroke rehabilitation outside the Cleveland Clinic health system. 59.3% had large vessel occlusions and 53.8% had moderate/severe disability (Modified Rankin score ≥ 2). PM was attempted in 21 participants, successful in 18. Nurses and patients rated the PM device as highly easy to use. 13 of 18 (72%) patients who had an REI ≥ 10 consented to APAP titration, but only eight (61.5%) of those 13 used APAP for more than one night, and only five (27.8%) used APAP up to 90 days with data captured for only one participant. Five required troubleshooting at titration, and only one had adherent APAP usage by objective assessment after discharge.

CONCLUSIONS

This study demonstrates the real-world challenges of assessing and treating OSA in an AIS population, highlighting the necessity for further research into timely and feasible screening and treatment.

Sleep Apnea and Stroke: A Narrative Review

TOPIC IMPORTANCE

Stroke is the second-leading cause of death worldwide. OSA is an independent risk factor for stroke and is associated with multiple vascular risk factors. Poststroke OSA is prevalent and closely linked with various stroke subtypes, including cardioembolic stroke and cerebral small vessel disease. Observational studies have shown that untreated poststroke OSA is associated with an increased risk of recurrent stroke, mortality, poorer functional recovery, and longer hospitalizations.

REVIEW FINDINGS

Poststroke OSA tends to be underdiagnosed and undertreated, possibly because patients with stroke and OSA present atypically compared with the general population with OSA. Objective testing, such as the use of ambulatory sleep testing or in-laboratory polysomnography, is recommended for diagnosing OSA. The gold standard for treating OSA is CPAP therapy. Randomized controlled trials have shown that treatment of poststroke OSA using CPAP improves nonvascular outcomes such as cognition and neurologic recovery. However, findings from randomized controlled trials that have evaluated the effect of CPAP on recurrent stroke risk and mortality have been largely negative.

SUMMARY

There is a need for high-quality randomized controlled trials in poststroke OSA that may provide evidence to support the utility of CPAP (and/or other treatment modalities) in reducing recurrent vascular events and mortality. This goal may be achieved by examining treatment strategies that have yet to be trialed in poststroke OSA, tailoring interventions according to poststroke OSA endotypes and phenotypes, selecting high-risk populations, and using metrics that reflect the physiologic abnormalities that underlie the harmful effects of OSA on cardiovascular outcomes.

Early screening of sleep disordered breathing in hospitalized stroke patients high-resolution pulse oximetry as prognostic and early intervention tools in patients with acute stroke and sleep apnea (HOPES TRIAL)

INTRODUCTION

Sleep Disordered Breathing (SDB) has been shown to increase the risk of stroke and despite recommendations, routine evaluation for SDB in acute stroke is not consistent across institutions. The necessary logistics and expertise required to conduct sleep studies in hospitalized patients remain a significant barrier. This study aims to evaluate the feasibility of high-resolution pulse-oximetry (HRPO) for the screening of SDB in acute stroke. Secondarily, considering impact of SDB on acute stroke, we investigated whether SDB at acute stroke predicts functional outcome at discharge and at 3 months post-stroke.

METHODS

Patients with acute mild to moderate ischemic stroke underwent an overnight HRPO within 48 h of admission. Patients were divided into SDB and no-SDB groups based on oxygen desaturations index(ODI > 10/h). Stepwise multivariate logistic regression analysis was applied to identify the relevant predictors of functional outcome (favorable [mRS 1-2 points] versus unfavorable [mrS > = 3 points]).

RESULTS

Of the 142 consecutively screened patients, 96 were included in the analysis. Of these, 33/96 (34%) were identified as having SDB and were more likely to have unfavorable mRS scores as compared to those without SDB (odds ratio = 2.70, p-value = 0.032).

CONCLUSION

HRPO may be a low-cost and easily administered screening method to detect SDB among patients hospitalized for acute ischemic stroke. Patients with SDB (as defined by ODI) have a higher burden of neurological deficits as compared to those without SDB during hospitalization.

The Influence of Obstructive Sleep Apnea on Post-Stroke Complications: A Systematic Review and Meta-Analysis

Objectives: Evidence shows that obstructive sleep apnea (OSA) is associated with the development of stroke. This study investigates the relationship between OSA and post-stroke complications, addressing the limited data on how OSA influences the severity and development of these complications through a systematic review of existing literature. Methods: Data was collected from PubMed, Web of Science, and Scopus databases up to December 2023. Studies meeting the inclusion criteria were selected, and statistical analyses were performed using Review Manager 5.4.1. A random-effects model was used for pooling data with heterogeneity, and findings were presented using standard ratios with 95% confidence intervals. Results: The analysis included nine studies. Stroke patients with OSA did not show a significantly higher risk of post-stroke complications, which include mild cognitive impairment, dementia, insomnia, fatigue, reduced sleep quality, depression, anxiety, recurrent strokes, and death, compared with those without OSA (RR = 1.05, 95% CI 0.97 to 1.13). However, patients with high stroke severity and OSA had a slightly higher risk of post-stroke complications (RR = 1.06, 95% CI 1.01 to 1.12). Conclusions: This systematic review and meta-analysis suggests that OSA confers a higher risk of post-stroke complications in patients with high stroke severity. Further studies are required to explore the impact of OSA on post-stroke complications.

Presence of Self-Reported Sleep Alterations After Stroke and Their Relationship With Disability: A Longitudinal Study

BACKGROUND

Sleep disorders have a prevalence of 30% to 70% in post-stroke individuals. The presence of sleep disorders and poor sleep quality after stroke can affect important functions and lead to worse outcomes. However, most studies are restricted to the acute post-stroke stage only.

OBJECTIVE

To investigate the frequency of self-reported sleep alterations in a sample of chronic stroke individuals and to identify which self-reported sleep alterations were associated with disability.

METHODS

Prospective exploratory study. Self-reported sleep alterations were measured by the Pittsburgh Sleep Quality Index, Insomnia Severity Index, Epworth Sleepiness Scale, and STOP-Bang Questionnaire. The dependent variable was measured 3 years after the first contact by the Modified Rankin Scale (mRS). Step-wise multiple linear regression analysis was employed to identify which sleep alterations were associated with disability.

RESULTS

Sixty-five individuals with stroke participated. About 67.7% of participants had poor sleep quality, 52.4% reported insomnia symptoms, 33.9% reported excessive daytime sleepiness, and 80.0% were classified as intermediate or high risk for obstructive sleep apnea. Only risk for obstructive sleep apnea was significantly associated with disability and explained 5% of the variance in the mRS scores.

CONCLUSION

Self-reported sleep alterations had a considerable frequency in a sample of chronic stroke individuals. The risk of obstructive sleep apnea was associated with disability in the chronic stage of stroke. Sleep alterations must be considered and evaluated in the rehabilitation process even after a long period since the stroke onset.

The relationship between sleep quality and gait in people with multiple sclerosis: A pilot study

Background

Gait deficits are common among people with multiple sclerosis (PwMS). Therefore, investigating factors that may influence walking in PwMS is important. Previous studies in older adults and other neurological populations demonstrated the relationship between sleep quality and gait performance. Despite the fact that the prevalence of poor sleep quality is very high among PwMS, little is known about the effect of sleep quality on gait among PwMS.

Objective

This study aimed to explore the relationship between sleep quality and gait performance in PwMS.

Methods

Forty-one PwMS participated in the study between February 2019 and December 2019. Participants were asked to walk at a self-selected speed over 10 m with an inertial measurement unit (IMU) attached over the back. Walking speed, step length (left and right), and step time were calculated. Sleep was estimated objectively using a wrist-worn triaxle-accelerometer; the derived parameters were sleep efficiency (SE) and the number of awakening after sleep onset (NASO).

Results

SE significantly correlated with step length (p = 0 . 02 ). Furthermore, the NASO significantly correlated with gait speed (p = 0 . 03 ), and step-time (p = 0 . 02 ). These correlations remained significant even after adjusting for age and disease duration.

Conclusion

We observed that when corrected for disease duration and age there were relationships between NASO and SE to gait parameters; these observations warrant further investigations.

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

Complement Proteins in Serum Astrocyte-Derived Exosomes Are Associated with Poststroke Cognitive Impairment in Type 2 Diabetes Mellitus Patients

Background

The complement system plays crucial roles in cognitive impairment and acute ischemic stroke (AIS). High levels of complement proteins in plasma astrocyte-derived exosomes (ADEs) were proven to be associated with Alzheimer's disease. We aimed to investigate the relationship of complement proteins in serum ADEs with poststroke cognitive impairment in type 2 diabetes mellitus (T2DM) patients.

Methods

This study analyzed 197 T2DM patients who suffered AIS. The Beijing version of the Montreal Cognitive Assessment (MoCA) was used to assess cognitive function. Complement proteins in serum ADEs were quantified using ELISA kits.

Results

Mediation analyses showed that C5b-9 and C3b in serum ADEs partially mediate the impact of obstructive sleep apnea (OSA), depression, small vessel disease (SVD), and infarct volume on cognitive function at the acute phase of AIS in T2DM patients. After adjusting for age, sex, time, and interaction between time and complement proteins in serum ADEs, the mixed linear regression showed that C3b and complement protein Factor B in serum ADEs were associated with MoCA scores at three-, six-, and twelve-months after AIS in T2DM patients.

Conclusions

Our study suggested that the impact of OSA, depression, SVD, and infarct volume on cognitive impairment in the acute stage of AIS may partially mediate through the complement proteins in serum ADEs. Additionally, the complement proteins in serum ADEs at the acute phase of AIS associated with MoCA scores at three-, six-, twelve months after AIS in T2DM patients.REGISTRATION: URL: http://www.chictr.org.cn/,ChiCTR1900021544.

Effects of inspiratory muscle training on the severity of obstructive sleep apnea in individuals after stroke: a protocol for a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing in cerebrovascular diseases, requiring a multidisciplinary approach. There are few studies evaluating the effects of inspiratory muscle training (IMT) in individuals with OSA and the findings regarding the possible effect on apnea hypopnea index (AHI) reduction are controversial.

OBJECTIVE

This protocol for a randomized clinical trial will assess the effects of IMT on the severity of obstructive sleep apnea, sleep quality, and daytime sleepiness in individuals after stroke participating in a rehabilitation program.

METHODS

This study will be a randomized controlled trial with blinded assessors. Forty individuals after stroke will randomized to two groups. For 5 weeks, both groups will participate in the rehabilitation program activities, including aerobic exercise, resistance training, and educational class when they will receive guidance on the behavioral management of OSA. The experimental group will also perform high-intensity IMT 5 times a week, for 5 weeks, consisting initially of five sets of five repetitions achieving 75% of the maximal inspiratory pressure, increasing one set each week, totaling nine sets at the end of training. The primary outcome will be the severity of OSA measured as AHI at 5 weeks. Secondary outcomes will include sleep quality measured by the Pittsburgh Sleep Quality Index (PSQI) and daytime sleepiness measured by Epworth Sleepiness Scale (ESS). Outcomes will be collected by a researcher blinded to group allocation at baseline (week 0), after intervention (week 5), and 1 month beyond intervention (week 9).

TRIAL REGISTRATION

Clinical Trials Register: NCT05135494.

Post-Stroke Brain Health Monitoring and Optimization: A Narrative Review

Significant advancements have been made in recent years in the acute treatment and secondary prevention of stroke. However, a large proportion of stroke survivors will go on to have enduring physical, cognitive, and psychological disabilities from suboptimal post-stroke brain health. Impaired brain health following stroke thus warrants increased attention from clinicians and researchers alike. In this narrative review based on an open timeframe search of the PubMed, Scopus, and Web of Science databases, we define post-stroke brain health and appraise the body of research focused on modifiable vascular, lifestyle, and psychosocial factors for optimizing post-stroke brain health. In addition, we make clinical recommendations for the monitoring and management of post-stroke brain health at major post-stroke transition points centered on four key intertwined domains: cognition, psychosocial health, physical functioning, and global vascular health. Finally, we discuss potential future work in the field of post-stroke brain health, including the use of remote monitoring and interventions, neuromodulation, multi-morbidity interventions, enriched environments, and the need to address inequities in post-stroke brain health. As post-stroke brain health is a relatively new, rapidly evolving, and broad clinical and research field, this narrative review aims to identify and summarize the evidence base to help clinicians and researchers tailor their own approach to integrating post-stroke brain health into their practices.

Prevalence and Outcomes of Depression, Obstructive Sleep Apnea, and Concurrent Anxiety (DOCA) in Stroke Survivors: Insights From a Nationwide Study

BACKGROUND

Many individuals will also experience psychological side effects after a stroke episode, such as symptoms of depression, anxiety (generalized anxiety disorder (GAD)), and/or specific phobias, considerably decreasing their quality of life (QOL).

OBJECTIVE

This study aimed to evaluate the prevalence of depression, obstructive sleep apnea (OSA), and concurrent anxiety (DOCA) and their outcomes (morbidity, disability (All Patient Refined Diagnosis Related Group (APRDRG) - loss of function), and discharge disposition) among acute ischemic stroke (AIS) hospitalizations.

METHODS

A cross-sectional study used the National Inpatient Sample (NIS) from 2003-2017. Adults with hospitalizations with AIS were extracted, and DOCA was identified using ICD-9/10-CM codes. Weighted analysis using a chi-square test and mixed-effect multivariable survey logistic regression was used to assess the prevalence and role of DOCA in predicting outcomes.

RESULTS

Out of 5,690,773 AIS hospitalizations, 2.7%, 3.1%, and 4.4% had depression, OSA, and GAD, respectively. In AIS patients, females had a higher prevalence of depression (3.4% vs. 2.3%) and GAD (5.9% vs. 3.0%) and a quality of life lower prevalence of OSA (2.2% vs 4.4%) in comparison to males (p<0.0001). Caucasians had a higher prevalence of depression, OSA, and GAD in comparison to others (African Americans/Hispanics/Asians/Native Americans). Depressed patients had a higher prevalence of morbidity (9% vs. 8% vs 5% vs. 7%), disability (46% vs. 46% vs. 35% vs. 37%), transfer to non-home (69% vs. 58% vs. 61% vs. 63%) in comparison with OSA, GAD, and non-DOCA patients, respectively (p<0.0001). Depression was associated with a 40% higher chance of severe disability (aOR 1.40; 95% CI 1.38-41), morbidity (1.36; 1.33-1.38), and discharge to non-home (1.54; 1.52-1.56). OSA and GAD had higher odds of non-home discharge amongst post-AIS hospitalizations.

CONCLUSION

DOCA is associated with poor outcomes among post-AIS patients. Prompt recognition by screening and timely management of DOCA may mitigate the adverse outcomes.

Disparities in brain health comorbidity management in intracerebral hemorrhage

Background

Intracerebral hemorrhage (ICH) disproportionally affects underserved populations, and coincides with risk factors for cardiovascular events and cognitive decline after ICH. We investigated associations between social determinants of health and management of blood pressure (BP), hyperlipidemia, diabetes, obstructive sleep apnea (OSA), and hearing impairment before and after ICH hospitalization.

Methods

Survivors of the Massachusetts General Hospital longitudinal ICH study between 2016 and 2019 who received healthcare at least 6 months after ICH were analyzed. Measurements of BP, LDL and HbA1c and their management in the year surrounding ICH and referrals for sleep studies and audiology up to 6 months after ICH were gathered from electronic health records. The US-wide area deprivation index (ADI) was used as proxy for social determinants of health.

Results

The study included 234 patients (mean 71 years, 42% female). BP measurements were performed in 109 (47%) before ICH, LDL measurements were performed in 165 (71%), and HbA1c measurements in 154 (66%) patients before or after ICH. 27/59 (46%) with off-target LDL and 3/12 (25%) with off-target HbA1c were managed appropriately. Of those without history of OSA or hearing impairment before ICH, 47/207 (23%) were referred for sleep studies and 16/212 (8%) to audiology. Higher ADI was associated with lower odds of BP, LDL, and HbA1c measurement prior to ICH [OR 0.94 (0.90-0.99), 0.96 (0.93-0.99), and 0.96 (0.93-0.99), respectively, per decile] but not with management during or after hospitalization.

Conclusion

Social determinants of health are associated with pre-ICH management of cerebrovascular risk factors. More than 25% of patients were not assessed for hyperlipidemia and diabetes in the year surrounding ICH hospitalization, and less than half of those with off-target values received treatment intensification. Few patients were evaluated for OSA and hearing impairment, both common among ICH survivors. Future trials should evaluate whether using the ICH hospitalization to systematically address co-morbidities can improve long-term outcomes.

Effect of CPAP on cognitive function in stroke patients with obstructive sleep apnoea: a meta-analysis of randomised controlled trials

OBJECTIVE

To investigate the effect of continuous positive airway pressure (CPAP) treatment on cognitive function in stroke patients with obstructive sleep apnoea (OSA) by exploring randomised controlled trials (RCTs).

METHODS

Published RCTs that assessed the therapeutic effects of CPAP on cognition in stroke patients with OSA, compared with controls or sham CPAP, were included. Electronic databases, including MEDLINE, Embase and Cochrane library, were searched in October 2020 and October 2021. Risk of bias was assessed using the Cochrane collaboration tools. A random effects or fixed effects model was used according to heterogeneity. The outcomes were global cognitive gain, improvement in cognitive domain and subjective sleepiness.

RESULTS

7 RCTs, including 327 participants, comparing CPAP with control or sham CPAP treatment were included. 6 RCTs with 270 participants reported results related to global cognition, and CPAP treatment had no significant effects on global cognitive gain in stroke patients with OSA (standardised mean difference (SMD), 0.18; 95% CI, -0.07 to 0.42; p=0.153). A subgroup analysis showed that an early start to (<2 weeks post stroke) CPAP treatment after stroke significantly improved global cognition (SMD, 0.66; 95% CI, 0.18 to 1.14; p=0.007), which was not found in the case of a delayed start to CPAP treatment. However, CPAP did not significantly help with memory, language, attention or executive function. Moreover, CPAP therapy significantly alleviated subjective sleepiness (SMD, -0.73; 95% CI, -1.15 to -0.32; p≤0.001).

CONCLUSIONS

Early initiation of CPAP treatment might contribute to improvement in global cognition in stroke patients with OSA. This study had the following limitations: the sample size in each included study was relatively small; the scales related to cognitive assessment or subjective sleepiness were inconsistent; and the methodological quality was not high. Future trials should focus on including a greater number of stroke patients with OSA undergoing CPAP treatment.

PROSPERO REGISTRATION NUMBER

CRD42020214709.

[Obstructive sleep apnea - underestimated cognitive impairments risk factor]

About 40% of cases of cognitive impairment (CI) are associated with modifiable risk factors, such as inactivity, hypertension, diabetes and obesity. Recently, sleep disorders, including obstructive sleep apnea syndrome (OSA), have been considered among these factors. OSA is one of the most widespread conditions among patients with CI. The pathogenesis of cerebral lesions in OSA is complex. Timely diagnosis and complex therapy of patients with OSA can reduce the risk, reduce the severity of CI and slow their progression. Along with non-drug methods of treatment, the use of the drug Cortexin with a multimodal mechanism of action can minimize the negative impact of OSA on the cognitive health of patients. Early detection and treatment of OSA can reduce the severity of CI and slow their progression.

Sleep Apnea and Cardiovascular Risk in Patients with Prediabetes and Type 2 Diabetes

Obstructive sleep apnea (OSA) is a common but largely undiagnosed clinical condition, which is turning into a serious public health issue. Of note is that its prevalence is gradually increasing in parallel with the obesity and type 2 diabetes mellitus (T2DM) epidemics. The aim of this article is to comprehensively review the literature in order to evaluate the cardiovascular (CV) risk among patients with OSA and prediabetes or T2DM. OSA seems to be an independent risk factor for the development as well as the progression of T2DM, whereas it is associated with T2DM-related macrovascular and microvascular complications. OSA may also act as a potential risk factor for the presentation and development of CV disease, such as hypertension, coronary artery disease, heart failure, pulmonary hypertension, atrial fibrillation and other cardiac arrythmias, as well as stroke. OSA and T2DM also share common pathophysiological mechanisms leading to atherosclerosis. Considering that the coexistence of OSA and T2DM is an independent and cumulative risk factor for CV mortality, more so than the two diseases separately, clinicians and healthcare professionals should be aware of and screen for OSA in patients with T2DM. Notably, targeted therapy for both conditions seems to substantially improve CV prognosis.

Associations of sleep apnea risk and oxygen desaturation indices with cerebral small vessel disease burden in patients with stroke

Background

Obstructive sleep apnea (OSA) is associated with cerebral small vessel disease (CSVD). Nonetheless, whether OSA-risk determined by a simple screening questionnaire or indices quantifying nocturnal hypoxemia other than the conventional apnea–hypopnea index (AHI) by the home sleep apnea test (HSAT) associated with CSVD burden remains uncertain.

Methods

From 2018 to 2021, we recruited patients with transient ischemic attack (TIA)/minor stroke from the Queen Mary Hospital Acute Stroke Unit and TIA/Stroke Outpatient Clinics. Logistic regression models were applied to determine the association of baseline OSA-risk (on STOP-BANG questionnaire) or HSAT-derived indices quantifying nocturnal hypoxemia with global burden/individual markers of CSVD on MRI. Indices included oxygen desaturation (≥3%) index (ODI), minimum oxygen saturation (SpO₂), percentage of total sleep time with an oxygen saturation <90% (CT90%), and desaturation duration (≥3%, DesDur).

Results

In 283 patients with TIA/minor stroke (mean age 65 years, 64% men), OSA-risk was significantly associated with total CSVD score (multivariate-adjusted odds ratio: 1.23, 95% confidence interval 1.01–1.51), presence of lacunes [1.39 (1.09–1.79)] and burden of basal ganglia PVSs [1.32 (1.06–1.67)]. In 85/283 patients who completed HSAT, neither AHI, minimum SpO₂ nor CT90% was associated with CSVD burden. Nonetheless, ODI and DesDur remained significantly associated with total CSVD score after covariate adjustment: ODI [1.04 (1.01–1.07)] and DesDur [1.04 (1.01–1.08)].

Conclusion

In patients with TIA/minor stroke, high OSA-risk was associated with a greater CSVD burden. Oxygen desaturation indices (ODI and DesDur) rather than AHI were independently associated with global CSVD burden, indicating that longer and more severe desaturations may contribute to the pathogenesis of CSVD.

Stroke: What's Sleep Got to Do With It?

SUMMARY

Ischemic strokes most often occur between 6 am and 12 am after awakening from sleep but up to 30% occur during sleep. Wake-up strokes (WUS) are new focal neurological deficit(s) persisting for ≥ 24 hours attributable to an ischemic event present on patient awakening. Obstructive sleep apnea (OSA) is a major risk factor for WUS because it compounds the instability of the morning environment and increases the likelihood of cardiovascular events, including hypertension, atrial fibrillation, right-to-left shunts, and stroke. Circadian-driven alterations in structural, homeostatic, and serological factors also predispose to WUS. Also, WUS patients are often not considered candidates for time-dependent intravenous thrombolysis therapy because of an uncertain onset time. However, using the tissue clock (positive diffusion weighted imaging-negative fluid-attenuated inversion recovery mismatch) dates the WUS as 3 to 4.5 hours old and permits consideration for intravenous thrombolysis and if needed mechanical thrombectomy. Given the high prevalence of moderate/severe OSA in stroke patients and its impact on stroke outcomes, screening with overnight pulse oximetry and home sleep apnea test is needed. Treating OSA poststroke remains challenging. Polysomnographic changes in sleep architecture following acute/subacute stroke may also impact upon stroke outcome.

Breathing Exercises for Improving Cognitive Function in Patients with Stroke

Patients with stroke may experience a certain degree of cognitive decline during the period of recovery, and a considerable number of such patients have been reported to show permanent cognitive damage. Therefore, the period of recovery and rehabilitation following stroke is critical for rapid cognitive functional improvements. As dysfunctional breathing has been reported as one of the factors affecting the quality of life post stroke, a number of studies have focused on the need for improving the breathing function in these patients. Numerous breathing exercises have been reported to enhance the respiratory, pulmonary, cognitive, and psychological functions. However, scientific evidence on the underlying mechanisms by which these exercises improve cognitive function is scattered at best. Therefore, it has been difficult to establish a protocol of breathing exercises for patients with stroke. In this review, we summarize the psychological, vascular, sleep-related, and biochemical factors influencing cognition in patients and highlight the need for breathing exercises based on existing studies. Breathing exercises are expected to contribute to improvements in cognitive function in stroke based on a diverse array of supporting evidence. With relevant follow-up studies, a protocol of breathing exercises can be developed for improving the cognitive function in patients with stroke.

Obstructive sleep apnea is associated with cognitive impairment in minor ischemic stroke

Objectives

Obstructive sleep apnea (OSA) is commonly seen in stroke patients, and its relationship with cognitive impairment remains poorly understood. This study aimed to explore the roles of OSA in cognition impairment in patients with minor ischemic stroke.

Methods

Patients with minor ischemic stroke were consecutively enrolled from January 2020 to May 2021. Every patient underwent polysomnography (PSG) to assess for OSA. Based on the apnea hypopnea index (AHI), patients were grouped into the no OSA (AHI < 5), mild OSA (5 ≤ AHI < 15), and moderate-to-severe OSA (MS OSA, AHI ≥ 15) groups. Neuropsychological assessments were performed to evaluate cognitive function, and the correlations between cognitive function and OSA were investigated.

Results

Of 94 patients, 35 had no OSA, 32 had mild OSA, and 27 had moderate-to-severe OSA. Compared to the no or mild OSA groups, the moderate-to-severe OSA group performed worse on the Chinese version of the Auditory Verbal Learning Test (CAVLT)-Recognition (p < 0.001), Digital Span Test (DST)-Backward (p < 0.001), Montreal Cognitive Assessment (MoCA) (p < 0.001), and Stroop Color and Word Test (SCWT)-Interference (p < 0.001). The severity of cognitive impairment was assessed using the MoCA, which was negatively related to the AHI (p = 0.041) and lowest SpO2 (p = 0.048).

Conclusions

The findings suggest that OSA has significant effects on cognition impairment in patients with minor ischemic stroke and that hypoxemia may be a potential pathophysiological mechanism of OSA-induced cognitive impairment.

Traditional Chinese Medicine for Post-stroke Sleep Disorders: The Evidence Mapping of Clinical Studies

BACKGROUND AND PURPOSE

Recently, there are a number of clinical studies on traditional Chinese medicine (TCM) for post-stroke sleep disorders (PSSDs). This study aimed to map the current clinical studies and identify gaps to inform future study agendas.

METHODS

PubMed, Embase, Cochrane Library, and Chinese databases, including SinoMed, CNKI, and Wanfang, were searched for clinical studies on PSSDs treated with TCM from their inception to September 2021. Evidence sources, number of studies, types of PSSDs, intervention categories, effectiveness, and quality assessment were graphically displayed.

RESULTS

The evidence map involved 810 clinical studies, of which the earliest report was dated back to 1993, and an advanced growth of the whole evidence was observed in 2012. Randomized controlled trials (RCTs) were the most common type of study design (78.15%), and post-stroke insomnia was the most common type of sleep disorders (65.80%). The benefits of Chinese herbal medicine (CHM) and acupuncture therapies for post-stroke insomnia have been widely reported in RCTs (81.60% and 75.38%, respectively). However, the benefits of CHM interventions were assessed using a global approach rather than being based on a specific formula, and the highest level of evidence supporting the effectiveness of acupuncture therapies was of low methodological quality. In addition, evidence from primary studies was insufficient in the areas of TCM for post-stroke sleep-related breathing disorders (SBDs) and Chinese mind-body exercises for post-stroke insomnia.

CONCLUSIONS

PSSDs treated with TCM have been widely assessed in clinical studies. For better evidence translation, clinical trials on specific CHM interventions and high-quality systematic reviews on acupuncture for post-stroke insomnia should be conducted. For a better solution to clinical questions, TCM on SBDs after stroke and the benefits of Chinese mind-body exercises for post-stroke insomnia should be explored in future clinical studies.

Association Between Pre-Stroke Subjective Sleep Status and Post-Stroke Cognitive Impairment: A Nationwide Multi-Center Prospective Registry

BACKGROUND

Although sleep disorders significantly increase the risk of cognitive impairment, literature is relatively scarce regarding the impact of sleep status on cognitive function in patients with acute ischemic stroke (AIS). We seek to study the association between pre-stroke subjective sleep status and cognitive function at 3 months after stroke.

PATIENTS AND METHODS

Data were analyzed for 1,759 AIS patients from the Impairment of Cognition and Sleep after Acute Ischemic Stroke or Transient Ischemic Attack in Chinese Patients Study (ICONS). Pre-stroke subjective sleep status was assessed by the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Greater sleep fragmentation was defined as waking up in the middle of the night or early morning ≥3 times a week. Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA) at 3 months after stroke. Primary endpoint was the incidence of post-stroke cognitive impairment (PSCI) at 3 months after stroke. The association between subjective sleep status and PSCI was evaluated using multivariable logistic regression.

RESULTS

PSCI occurred in 52.1% at 3 months after stroke. Patients with very bad sleep quality before stroke were at increased risk of PSCI (OR, 2.11; 95% CI, 1.11-4.03; P=0.03). Subgroup analysis found that the association between very bad sleep quality and PSCI was more evident among patients with high school education or above (OR, 5.73; 95% CI, 1.92-17.10; P for interaction=0.02). In addition, patients with greater sleep fragmentation before stroke were also at higher risk of PSCI (OR, 1.55; 95% CI, 1.20-2.01; P<0.01). Similarly, subgroup analysis showed that the risk of PSCI was more pronounced among patients without employment (OR, 2.45; 95% CI, 1.59-3.77; P for interaction=0.01).

CONCLUSION

Very bad sleep quality and greater sleep fragmentation before stroke were identified as independent risk factors for PSCI at 3 months after stroke.

Prevalence and Determinants of Sleep Apnea in Patients with Stroke: A Meta-Analysis

OBJECTIVES

Recent meta-analyses have noted that ∼70% of transient ischemic attack (TIA)/stroke patients have sleep apnea. However, the heterogeneity between studies was high and did not appear to be accounted by the phase of stroke. We conducted an updated meta-analysis and aimed to determine whether the prevalence of sleep apnea amongst stroke patients differs by the subtype, etiology, severity and location of stroke and hence could account for some of the unexplained heterogeneity observed in previous studies.

MATERIALS AND METHODS

We searched Medline, Embase, CINAHL and Cochrane Library (from their commencements to July 2020) for studies which reported the prevalence of sleep apnea by using polysomnography in TIA/stroke patients. We used random-effects model to calculate the pooled prevalence of sleep apnea and explored whether the prevalence differed by stroke characteristics.

RESULTS

Seventy-five studies describing 8670 stroke patients were included in this meta-analysis. The overall prevalence of sleep apnea was numerically higher in patients with hemorrhagic vs. ischemic stroke [82.7% (64.4-92.7%) vs. 67.5% (63.2-71.5%), p=0.098], supratentorial vs. infratentorial stroke [64.4% (56.7-71.4%) vs. 56.5% (42.2-60.0%), p=0.171], and cardioembolic [74.3% (59.6-85.0%)] vs. other ischemic stroke subtypes [large artery atherosclerosis: 68.3% (52.5-80.7%), small vessel occlusion: 56.1% (38.2-72.6%), others/undetermined: 47.9% (31.6-64.6%), p=0.089]. The heterogeneity in sleep apnea prevalence was partially accounted by the subtype (1.9%), phase (5.0%) and location of stroke (14.0%) among reported studies.

CONCLUSIONS

The prevalence of sleep apnea in the stroke population appears to differ by the subtype, location, etiology and phase of stroke.

Sleep disturbance and length of stay in the setting of acquired brain injury rehabilitation

OBJECTIVE

The objective of this study was to investigate the impact and prevalence of sleep-wake disturbances among adult patients admitted for inpatient acquired brain injury rehabilitation.

METHOD

This was a retrospective cohort study involving all adults admitted for inpatient ABI neurocognitive rehabilitation at UHN-Toronto Rehabilitation Institute over a 12-month period (n = 165). The primary endpoint of the study was the comparison of functional independent measure efficiency and hospital length of stay between patients reporting sleep disturbance (e.g. increased sleep latency, obstructive sleep apnea [OSA], sleep maintenance insomnia) versus those with normal sleep.

RESULTS

We found that more than half (58.2%) of patients experienced sleep disturbance based on a combination of self-report and clinical documentation. The most common sleep disturbance was increased sleep onset latency (28.5%), followed by mixed sleep onset/maintenance insomnia (14.5%) and obstructive sleep apnea (8.5%). Notably, OSA was associated with longer length of hospital stay and reduced functional independence measure (FIM) efficiency in the cognitive domain after accounting for age and number of medical comorbidities.

IMPLICATIONS

The results of this investigation underscore the importance of screening patients with brain injury for sleep disturbances due to its high prevalence and impact on rehabilitation efficiency.

Sleep disordered breathing as a cause and consequence of stroke: A review of pathophysiological and clinical relationships

Stroke is the leading cause of death and disability globally. Sleep disordered breathing (SDB), a potentially modifiable risk factor of stroke, is highly prevalent in stroke survivors. Evidence supports a causal, bidirectional relationship between SDB and stroke. SDB may increase the risk of stroke occurrence and recurrence, and worsen stroke outcome. While SDB is associated with an increased incidence of hypertension and cardiac arrhythmias, both of which are traditional stroke risk factors, SDB is also an independent risk factor for stroke. A number of characteristics of SDB may increase stroke risk, including intermittent hypoxemia, sympathetic activation, changes in cerebral autoregulation, oxidative stress, systemic inflammation, hypercoagulability, and endothelial dysfunction. On the other hand, stroke may also cause new SDB or aggravate preexisting SDB. Continuous positive airway pressure treatment of SDB may have a beneficial role in reducing stroke risk and improving neurological outcome after stroke. The treatment should be considered as early as possible, particularly when SDB is present post-stroke. The goal of this review is to highlight the strong link between SDB and stroke and to raise awareness for practitioners to consider the possibility of SDB being present in all stroke survivors.

Sleep Disturbance and Disorders within Adult Inpatient Rehabilitation Settings: A Systematic Review to Identify Both the Prevalence of Disorders and the Efficacy of Existing Interventions

OBJECTIVES

Older people who are admitted to inpatient rehabilitation settings often experience sleep disturbance or disorders. Both intrinsic and environmental factors may contribute to reduced sleep quality. Poor sleep quality has been reported to be associated with poorer rehabilitation outcomes. The aim of this review was (1) to describe the prevalence of sleep disturbance or disorder among older people participating in inpatient rehabilitation, and (2) to describe interventions that have been trialed to increase sleep quality and/or quantity in older people in rehabilitation settings and report on their efficacy.

DESIGN

Systematic review involving search of 3 electronic databases and gray literature. Two authors independently reviewed citations and reviewed full text and agreed on included studies. Data were extracted and synthesized and risk of bias was assessed.

SETTING AND PARTICIPANTS

Studies were included if they provided quantitative data about the prevalence of sleep disturbance or disorder in older people in a rehabilitation setting or if they reported the results of a randomized trial evaluating an intervention to improve sleep quality in older people in a rehabilitation setting.

MEASURES

Studies were included if they reported data from monitoring (such as polysomnography or actigraphy), clinical assessments, or questionnaires.

RESULTS

16 studies reporting prevalence data and 3 studies reporting evaluations of interventions were included in this review. Studies reported data from stroke and mixed population rehabilitation settings. The prevalence of obstructive sleep apnea was high and ranged from 12% to 92% in stroke rehabilitation settings. Other types of sleep disturbance, such as difficulty initiating sleep, were also common.

CONCLUSIONS AND IMPLICATIONS

Many older people participating in inpatient rehabilitation have sleep disturbance or sleep disorders. Poor sleep quality is associated with poorer health status and recovery; therefore, it is important that rehabilitation settings take steps to enhance sleep quality for inpatients drawing on the principles of good sleep hygiene.

The Impact of Sleep Disorders on Functional Recovery and Participation Following Stroke: A Systematic Review and Meta-Analysis

Background

Adequate sleep is vital for health and quality of life. People with stroke and a concomitant sleep disorder may have poorer outcomes than those without a sleep disorder.

Objective

To systematically evaluate the published literature to determine the impact of sleep disorders on physical, functional recovery at the activity and participation level after stroke.

Methods

A systematic review was conducted using PubMed, CINAHL, Scopus, and PsycINFO. Studies were selected that reported outcomes on physical, functional recovery at the activity and participation levels in participants with stroke and a diagnosed sleep disorder. A meta-analysis was performed on included studies that reported Barthel Index (BI) and modified Rankin Scale (mRS) scores. Results: A total of 33 studies were included in the systematic review with 9 of them in the meta-analysis. The mean mRS score was 0.51 points higher in participants with stroke and sleep disorders versus participants with stroke without sleep disorder [95% CI: 0.23-0.78]. The mean BI score was 10.2 points lower in participants with stroke and sleep disorders versus participants with stroke without sleep disorder [95% CI: −17.9 to −2.6].

Conclusions

People with stroke and a sleep disorder have greater functional limitations and disability than those without a sleep disorder. Rehabilitation professionals should screen their patients with stroke for potential sleep disorders and further research is needed to develop sleep and rehabilitation interventions that can be delivered in combination. PROSPERO registration number: CRD42019125562.

Pathophysiologic mechanisms, neuroimaging and treatment in wake-up stroke

Wake-up stroke (WUS) or ischemic stroke occurring during sleep accounts for 14%-29.6% of all ischemic strokes. Management of WUS is complicated by its narrow therapeutic time window and attributable risk factors, which can affect the safety and efficacy of administering intravenous (IV) tissue plasminogen activator (t-PA). This manuscript will review risk factors of WUS, with a focus on obstructive sleep apnea, potential mechanisms of WUS, and evaluate studies assessing safety and efficacy of IV t-PA treatment in WUS patients guided by neuroimaging to estimate time of symptom onset. The authors used PubMed (1966 to March 2018) to search for the term "Wake-Up Stroke" cross-referenced with "pathophysiology," ''pathogenesis," "pathology," "magnetic resonance imaging," "obstructive sleep apnea," or "treatment." English language Papers were reviewed. Also reviewed were pertinent papers from the reference list of the above-matched manuscripts. Studies that focused only on acute Strokes with known-onset of symptoms were not reviewed. Literature showed several potential risk factors associated with increased risk of WUS. Although the onset of WUS is unknown, a few studies investigated the potential benefit of magnetic resonance imaging (MRI) in estimating the age of onset which encouraged conducting clinical trials assessing the efficacy of MRI-guided thrombolytic therapy in WUS.

Sleep-related symptoms in patients with mild stroke

STUDY OBJECTIVES

Treatable sleep-related conditions are frequent in stroke patients, although their prevalence across stroke types and ideal method for screening is not clear. The objectives of this study were to evaluate the prevalence of sleep disturbance across different stroke types and identify approaches to the collection of sleep-related measures in clinical practice.

METHODS

We performed an observational cohort study of 2,213 patients with ischemic stroke, intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), or transient ischemic attack seen in a cerebrovascular clinic February 17, 2015 through July 5, 2017 who completed at least one of the following sleep-related questionnaires: Patient-Reported Outcomes Measurement Information System (PROMIS) sleep disturbance, Insomnia Severity Index (ISI), Sleep Apnea Probability Scale (SAPS), and sleep duration. Prevalence of abnormal scores were calculated using the following thresholds: PROMIS sleep disturbance ≥ 55, ISI ≥ 15, SAPS score ≥ 0.50, and sleep duration fewer than 6 or more than 9 hours. Sensitivity, specificity, and positive and negative predictive values of PROMIS sleep disturbance T-score ≥ 55 to identify patients with moderate-severe insomnia (ISI ≥ 15) were computed.

RESULTS

In the cohort, 28.6% patients (624/2183) had PROMIS sleep disturbance score ≥ 55, 17.6% (142/808) had ISI ≥ 15, and 61.3% (761/1241) had a positive SAPS screen. The frequency of abnormal sleep scale scores was similar across time periods and stroke types. The sensitivity and specificity of PROMIS sleep disturbance T-score ≥ 55 to identify patients with ISI ≥ 15 were 0.89 (95% confidence interval 0.83-0.94) and 0.81 (95% confidence interval 0.78-0.84), respectively.

CONCLUSIONS

The prevalence of sleep-related symptoms in patients with mild stroke are similar across stroke types and time periods after stroke. Potential approaches to screening for sleep disturbance in stroke patients are provided.

Obstructive sleep apnea and cardiovascular disease, a story of confounders!

Obstructive sleep apnea (OSA) syndrome is increasingly common among middle aged and older adults and is frequently linked to most cardiovascular diseases (CVD). Sleep-disordered breathing and CVD share a number of common risk factors and comorbid conditions including obesity, male gender, advancing age, metabolic syndrome, and hypertension. OSA appears to be associated with worsened CVD outcomes, sleep-related symptoms, quality of life, and risk of motor vehicle accidents. Demonstrating a cause-and-effect relationship between CVD and OSA has been challenging due to shared comorbidities. Strong evidence demonstrating clinically significant benefit for OSA treatments on OSA-related CVD outcomes are limited. In this review, we evaluate potential pathophysiologic mechanisms that link OSA to CVD and focus on specific treatments for OSA, including positive airway pressure (PAP), dental devices, and surgeries with regard to OSA-related CVD outcomes.

Frequency and outcomes of primary central sleep apnea in a population-based study

BACKGROUND

Primary central sleep apnea (PCSA) is believed to be rare and data regarding its prevalence and long-term outcomes are sparse. We used the Rochester Epidemiology Project (REP) resources to identify all Olmsted County, Minnesota, residents with an incident diagnosis of PCSA and their clinical outcomes.

METHODS

We searched the REP database for all residents with polysomnography (PSG)-confirmed diagnoses of central sleep apnea (CSA) between 2007 and 2015. From these, we reviewed the PSGs and medical records to find those who had PCSA based upon accepted diagnostic criteria. Data based on detailed review of the medical records, including all clinical notes and tests were recorded for analysis.

RESULTS

Of 650 patients identified with CSA, 25 (3.8%; 23 male) had PCSA, which was severe in most patients (n = 16, 64%). Of those, 23 (92%) patients were prescribed and 18/23 (78.2%) adherent to positive airway pressure therapy. Median duration of follow-up was 4.4 years (IQR:4.2). Four (16%) patients were subsequently diagnosed with cardiac arrhythmias, one (4%) with unstable angina, two (8%) with heart failure, five (20%) with mild cognitive impairment (MCI)/dementia and two (8%) with depression. Six (25%) patients died (median time to death = 5 years; IQR:4.8), three of whom had Lewy body dementia.

CONCLUSIONS

In this population-based study, PCSA was rare and when present, was severe in a majority of patients. The mortality rate was high. Most frequently observed disorders during follow-up were mild cognitive impairment (MCI)/dementia followed by cardiac arrhythmias; it is possible that these entities were present and not recognized prior to the diagnosis of PCSA.

Stroke impact symptoms are associated with sleep-related impairment

BACKGROUND

Sleep-related impairment is a common but under-appreciated complication after stroke and may impede stroke recovery. Yet little is known about factors associated with sleep-related impairment after stroke.

OBJECTIVE

The purpose of this analysis was to examine the relationship between stroke impact symptoms and sleep-related impairment among stroke survivors.

METHODS

We conducted a cross-sectional secondary analysis of a baseline (entry) data in a completed clinical trial with 100 community-dwelling stroke survivors recruited within 4 months after stroke. Sleep-related impairment and stroke impact domain symptoms after stroke were assessed with the Patient-Reported Outcomes Measurement Information System Sleep-Related Impairment scale and the Stroke Impact Scale, respectively. A multivariate regression was computed.

RESULTS

Stroke impact domain-mood (B = -0.105, t = -3.263, p = .002) - and fatigue (B = 0.346, t = 3.997, p < .001) were associated with sleep-related impairment.

CONCLUSIONS

Our findings suggest that ongoing stroke impact symptoms are closely related to sleep-related impairment. An intervention targeting both stroke impact symptoms and sleep-related impairment may be useful in improving neurologic recovery and quality of life in stroke survivors.

Improvement of Cognitive Function after Continuous Positive Airway Pressure Treatment for Subacute Stroke Patients with Obstructive Sleep Apnea: A Randomized Controlled Trial

Background: Obstructive sleep apnea (OSA) is common after stroke. Various studies on continuous positive airway pressure (CPAP) therapy for OSA after stroke have been published. However, there have been no studies from Korea and Asia. The present Korean study aimed to determine whether CPAP treatment during inpatient rehabilitation of stroke patients with sleep disorders, especially OSA, improves function, cognition, sleep quality, and daytime sleepiness. Methods: This single-blind randomized controlled study included 40 stroke patients with OSA between November 2017 and November 2018. The patients were divided into the CPAP treatment group (CPAP and rehabilitation; n = 20) and control group (only rehabilitation; n = 20). The intervention period was 3 weeks. The primary outcomes were function and cognition improvements, and the secondary outcomes were sleep-related improvements. Results: CPAP treatment started at an average of 4.6 ± 2.8 days after admission. Both groups showed improvements in stroke severity, function, and cognition after the 3-week intervention. However, after the intervention, the degree of change in attention and calculation was significantly higher in the CPAP treatment group than in the control group. Additionally, the improvements in sleep quality and daytime sleepiness were greater in the CPAP treatment group than in the control group. Conclusion: CPAP treatment can improve cognitive function, sleep quality, and daytime sleepiness, and it should be considered as part of the rehabilitation program for patients with stroke. Our findings might help in the treatment of stroke patients with OSA in Korea.

Sleep Apnea and Cardiovascular Disease: An Enigmatic Risk Factor

Synchronization of molecular, metabolic, and cardiovascular circadian oscillations is fundamental to human health. Sleep-disordered breathing, which disrupts such temporal congruence, elicits hemodynamic, autonomic, chemical, and inflammatory disturbances with acute and long-term consequences for heart, brain, and circulatory and metabolic function. Sleep apnea afflicts a substantial proportion of adult men and women but is more prevalent in those with established cardiovascular diseases and especially fluid-retaining states. Despite the experimental, epidemiological, observational, and interventional evidence assembled in support of these concepts, this substantial body of work has had relatively modest pragmatic impact, thus far, on the discipline of cardiology. Contemporary estimates of cardiovascular risk still are derived typically from data acquired during wakefulness. The impact of sleep-related breathing disorders rarely is entered into such calculations or integrated into diagnostic disease-specific algorithms or therapeutic recommendations. Reasons for this include absence of apnea-related symptoms in most with cardiovascular disease, impediments to efficient diagnosis at the population level, debate as to target, suboptimal therapies, difficulties mounting large randomized trials of sleep-specific interventions, and the challenging results of those few prospective cardiovascular outcome trials that have been completed and reported. The objectives of this review are to delineate the bidirectional interrelationship between sleep-disordered breathing and cardiovascular disease, consider the findings and implications of observational and randomized trials of treatment, frame the current state of clinical equipoise, identify principal current controversies and potential paths to their resolution, and anticipate future directions.

Sleep-disordered breathing and poststroke outcomes

OBJECTIVE

To examine the association between sleep-disordered breathing and stroke outcomes, and determine the contribution of sleep-disordered breathing to outcome disparities in Mexican Americans.

METHODS

Ischemic stroke patients (n = 995), identified from the population-based Brain Attack Surveillance in Corpus Christi Project (2010-2015), were offered participation in a sleep-disordered breathing study including a home sleep apnea test (ApneaLink Plus). Sleep-disordered breathing (respiratory event index ≥10) was determined soon after stroke. Neurologic, functional, cognitive, and quality of life outcomes were assessed at 90 days poststroke. Regression models were used to assess associations between sleep-disordered breathing and outcomes, adjusted for sociodemographics, prestroke function and cognition, health-risk behaviors, stroke severity, and vascular risk factors.

RESULTS

Median age was 67 years (interquartile range [IQR] = 59-78); 62.1% were Mexican American. Median respiratory event index was 14 (IQR = 6-25); 62.8% had sleep-disordered breathing. Sleep-disordered breathing was associated with worse functional outcome (mean difference in activities of daily living/instrumental activities of daily living score = 0.15, 95% confidence interval [CI] = 0.01-0.28) and cognitive outcome (mean difference in modified Mini-Mental State Examination = -2.66, 95% CI = -4.85 to -0.47) but not neurologic or quality of life outcomes. Sleep-disordered breathing accounted for 9 to 10% of ethnic differences in functional and cognitive outcome and was associated with cognitive outcome more strongly for Mexican Americans (β = -3.97, 95% CI = -6.63 to -1.31) than non-Hispanic whites (β = -0.40, 95% CI = -4.18 to 3.39, p-interaction = 0.15).

INTERPRETATION

Sleep-disordered breathing is associated with worse functional and cognitive function at 90 days poststroke. These outcomes are reasonable endpoints for future trials of sleep-disordered breathing treatment in stroke. If effective, sleep-disordered breathing treatment may somewhat lessen ethnic stroke outcome disparities. ANN NEUROL 2019;86:241-250.

Evaluation of an OSA risk stratifying and treatment protocol during inpatient rehabilitation of post-stroke patients

PURPOSE

To evaluate outcomes, outside of a clinical trial setting, of a protocol utilizing overnight oximetry (NOx) to risk stratify post-stroke patients for obstructive sleep apnea (OSA) followed by autoadjusting continuous positive airway pressure (APAP) treatment in patients considered high risk for OSA.

METHODS

Retrospective observational study of post-stroke patients at an academic inpatient stroke rehabilitation facility. Patients underwent NOx, and those at high risk for OSA (oxygen desaturation index 3% > 10 per hour) were attempted on a trial of APAP, and further stratified into high risk adherent with treatment (HRAT) or high-risk failed treatment (HRFT). Change in functional independence measure (FIM) was used to assess recovery.

RESULTS

Two hundred twenty-four post-stroke patients underwent NOx, with 120 (53%) considered high risk for OSA. Twelve (10%) were compliant with APAP treatment (> 4 h/night on > 70% of nights). No difference in change in FIM scores was observed for HRAT versus HRFT [total FIM change - 5.8, 95% CI (- 13.9, 2.2); motor FIM change - 4.5, 95% CI (- 11.5, 2.4); cognitive FIM change - 1.3, 95% CI (-3.8, 1.2)]. A subgroup analysis matched 14 HRAT patients (using adherence criterion of APAP usage > 50% of nights) to 35 HRFT patients. A statistically significant, but clinically irrelevant, difference in total FIM change was observed (HRAT vs HRFT, difference between means - 5.2, p = 0.03).

CONCLUSIONS

The use of APAP in high-risk patients was poorly tolerated and did not improve post-stroke recovery. Further studies with larger sample sizes are needed to determine the effect of APAP treatment on short-term recovery.

Effects of continuous positive airway pressure (CPAP) therapy on neurological and functional rehabilitation in Basal Ganglia Stroke patients with obstructive sleep apnea: A prospective multicenter study

Obstructive sleep apnea (OSA) adversely affects neurological recovery. This study aimed to determine the impact of continuous positive airway pressure (CPAP) and/or rehabilitation in basal ganglia stroke patients with OSA.A prospective controlled trial was conducted in 2015-2018. The subjects received routine rehabilitation training for up to 2 years and were assigned to the intervention and control groups treated with CPAP or without, respectively. Then, treatment effects on sleep parameters, motor function, stroke severity, daily life activities, cognitive function, and psychological states were assessed at different time points.At 6 months, the CPAP group showed significantly lower mean apnea-hypopnea index (AHI), percentage of time with SpO2 at <90% (TS90%), micro-arousal index, and percentages of time in non-rapid eye movement (non-REM) stages 1-2 and REM stage in total sleeping time compared with the control group, and significantly higher mean minimum of peripheral oxygen saturation (L-SaO2%) and percentage of time in stage 3 (P < .001) sleep. The CPAP group showed significant improvements in average the National Institutes of Health Stroke Scale (NIHSS), Fugl-Meyer assessment scale (FMA), Barthel index (BI), Minimental state examination (MMSE), Hamilton anxiety scale (HAMA) and Hamilton depression rating scale for depression (HRSD) scores at different times versus the control group, respectively (P < .05). However, no difference in body mass index (BMI) management was observed (P > .05). Repeated-measures ANOVA revealed significant interactions between the two groups for change in FMA, MMSE, BI, HAMA, and HRSD scores from admission to 24 months (P < .001), but no significant was found for BMI (P = .582).Basal ganglia stroke patients with OSA tend to have significantly greater sleeping, neurological and functional recovery after CPAP, and rehabilitation over 2 years.

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

PURPOSE OF REVIEW

This review aims to discuss the most recent data on sleep disorders and stroke, highlighting relevant findings for the practicing neurologist or health providers who encounter patients with sleep disorders and stroke.

RECENT FINDINGS

Sleep apnea and abnormal sleep duration have the strongest association with stroke risk. Possible mechanisms include non-dipping of blood pressure during sleep, hypoxemia or reoxygenation leading to sympathetic activation, hypertension, atrial fibrillation and impaired cerebral hemodynamics. Treatment studies suggest that continuous positive airway pressure (CPAP) for sleep apnea could improve primary prevention of stroke, but data is equivocal for secondary prevention. However, CPAP could improve functional outcomes after stroke.

SUMMARY

Sleep disorders present an opportunity to improve stroke risk and functional outcomes. However, new strategies are needed to determine the patients at high-risk who would most likely benefit from targeted care. Novel methods for phenotyping sleep disorders could provide personalized stroke care to improve clinical outcomes and public health strategies.

Continuous positive airway pressure improves nocturnal polyuria in ischemic stroke patients with obstructive sleep apnea

Objectives

To assess the effect of continuous positive airway pressure (CPAP) on nocturia in ischemic stroke patients with obstructive sleep apnea (OSA).

Methods

This was a prospective and non-randomized controlled study in which ischemic stroke patients with OSA being treated in a rehabilitation ward were enrolled. The participants who tolerated CPAP were classified as the CPAP group, while those who refused or could not tolerate CPAP were classified as the control group. The percentage change of nocturia before and after 2 weeks of CPAP therapy between the two groups were compared.

Results

A total of 44 participants were enrolled in and 35 participants (mean age= 59.8±11.7 years old; mean apnea hypopnea index=42.9±16.7/h) completed the study (control group: 14, CPAP group: 21). Overall, 69% of the participants had nocturnal polyuria and 69% of them had more than one nocturia episode per night. The baseline and initial nocturia characteristics did not differ significantly between the two groups. As compared to the control group, CPAP therapy significantly decreased the nocturnal polyuria index (mean percentage change: 9% vs −21% (P=0.005)) and nocturnal urine output (mean percentage change: 6% vs −26% (P=0.04)), but not the nocturia episodes or 24-hours total urine output.

Conclusion

Nocturia due to nocturnal polyuria is very common in post-stroke patients with OSA. Treating OSA by CPAP significantly reduces nocturnal polyuria, but not nocturia frequency, in ischemic stroke patients.

Prevalence of sleep-disordered breathing after stroke and TIA: A meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis on the prevalence of sleep-disordered breathing (SDB) after stroke.

METHODS

We searched PubMed, Embase (Ovid), the Cochrane Library, and CINAHL (from their commencements to April 7, 2017) for clinical studies reporting prevalence and/or severity of SDB after stroke or TIA. Only sleep apnea tests performed with full polysomnography and diagnostic devices of the American Academy of Sleep Medicine categories I-IV were included. We conducted random-effects meta-analysis. PROSPERO registration number: CRD42017072339.

RESULTS

The initial search identified 5,211 publications. Eighty-nine studies (including 7,096 patients) met inclusion criteria. Fifty-four studies were performed in the acute phase after stroke (after less than 1 month), 23 studies in the subacute phase (after 1-3 months), and 12 studies in the chronic phase (after more than 3 months). Mean apnea-hypopnea index was 26.0/h (SD 21.7-31.2). Prevalence of SDB with apnea-hypopnea index greater than 5/h and greater than 30/h was found in 71% (95% confidence interval 66.6%-74.8%) and 30% (95% confidence interval 24.4%-35.5%) of patients, respectively. Severity and prevalence of SDB were similar in all examined phases after stroke, irrespective of the type of sleep apnea test performed. Heterogeneity between studies (I ²) was mostly high.

CONCLUSION

The high prevalence of SDB after stroke and TIA, which persists over time, is important in light of recent studies reporting the (1) feasibility and (2) efficacy of SDB treatment in this clinical setting.