Prevalence and clinical importance of sleep apnea in the first night after cerebral infarction

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.

From Molecular to Clinical Implications of Sleep-Related Breathing Disorders on the Treatment and Recovery of Acute Stroke: A Scoping Review

(1) Background: The aim of this review is to map research into the molecular mechanisms linking sleep-related breathing disorders (SRBDs) and acute stroke and their clinical and therapeutic implications and to identify existing knowledge gaps to suggest new areas of research. (2) Methods: This review was conducted according to the PRISMA extension for scoping reviews (PRISMA-ScR) and a predetermined protocol shared among all authors. (3) Results: The review of the thirteen studies analyzed provides a focused view of the molecular features about interaction between obstructive sleep apnea (OSA) and acute stroke. Our review identifies and highlights the biomarkers most frequently found to be associated with acute stroke, SRBDs, and their clinical repercussions. (4) Conclusions: The association between the presence of sleep apnea, especially in its severe form, and elevated levels of inflammatory markers in patients with acute stroke is highlighted and new research topics in this area are proposed.

Effectiveness and feasibility of continuous positive airway pressure in patients with stroke and sleep apnea: a meta-analysis of randomized trials

STUDY OBJECTIVES

This meta-analysis aimed to investigate the feasibility and effectiveness of continuous positive airway pressure (CPAP) treatment in stroke patients with sleep apnea.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched from inception until July 28, 2022, for randomized controlled trials comparing the use of CPAP and usual treatment in patients with stroke or transient ischemic attack and sleep apnea. The primary outcome measures were the feasibility of CPAP therapy, neurological function, and functional status.

RESULTS

After screening 5,747 studies, 14 studies with 1,065 patients were included in this meta-analysis. Overall, 8 of the 14 studies recorded CPAP use, and the mean CPAP use was 4.47 hours per night (95% confidence interval [CI]: 3.85-5.09). The risk ratio of discontinuing CPAP was 1.50 (95% CI: 0.76-2.94; P = .24). Analysis of the neurofunctional scales showed that CPAP treatment improved neurological function (standardized mean difference: 0.28; 95% CI: 0.02-0.53), but there was substantial heterogeneity (I2 = 57%, P = .03) across the studies. CPAP treatment had no significant effect on functional status vs the control (standardized mean difference: 0.25; 95% CI: -0.01 to 0.51), but the studies also had substantial heterogeneity (I2 = 55%, P = .06).

CONCLUSIONS

CPAP treatment is feasible in patients with stroke and sleep apnea and may improve neurological outcomes in these patients. However, this finding should be interpreted with caution because of the substantial heterogeneity of current trials.

CITATION

Fu S, Peng X, Li Y, Yang L, Yu H. Effectiveness and feasibility of continuous positive airway pressure in patients with stroke and sleep apnea: a meta-analysis of randomized trials. J Clin Sleep Med. 2023;19(9):1685-1696.

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.

Sleep-Disordered Breathing in Acute Stroke: A Single-Center, Prospective, Longitudinal Study

BACKGROUND

Sleep-disordered breathing (SDB) is common among acute stroke patients. We sought to investigate the prevalence, severity and type of SDB in consecutive acute stroke patients. Moreover, we aimed to identify independent predictors of SDB in the acute stroke setting and investigate potential associations between SDB and functional outcomes at three months.

METHODS

We prospectively studied consecutive acute stroke patients, who underwent overnight polysomnography within 72 h from symptom onset. Demographics, clinical and imaging characteristics were documented. Daytime sleepiness preceding the stroke, stroke severity on admission and functional outcome at three months were evaluated using the Epworth-Sleepiness Scale (ESS), National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS), respectively. SDB was documented using standard polysomnography criteria.

RESULTS

A total of 130 consecutive acute stroke patients were prospectively evaluated [110 with ischemic stroke and 20 with intracerebral hemorrhage, mean age 60.5 ± 10.9 years, 77% men, median NIHSS score on admission: 3 (IQR: 2-17)]. The rate of SDB detection on polysomnography recordings was 79% (95% CI: 71-86). Three variables were independently associated with the likelihood of SDB detection in multivariable analyses adjusting for potential confounders: age (OR per 10-year-increase: 2.318, 95% CI: 1.327-4.391, p = 0.005), male sex (OR: 7.901, 95% CI: 2.349-30.855, p = 0.001) and abnormal ESS-score (OR: 6.064, 95% CI: 1.560-32.283, p = 0.017). Among patients with SDB, congestive heart failure was independently associated with the likelihood of central apnea detection (OR: 18.295, 95% CI: 4.464-19.105, p < 0.001). Among all patients, increasing NIHSS score on admission (OR: 0.817, 95% CI: 0.737-0.891, p < 0.001) and Apnea-Hypopnea Index (OR: 0.979, 95% CI: 0.962-0.996, p = 0.020) emerged as independent predictors of excellent functional outcome at 3 months (mRS-scores 0-1).

CONCLUSION

The high prevalence and severity of SDB in acute stroke patients and its negative impact on functional outcome indicate the importance of polysomnography implementation in everyday clinical practice of acute stroke work-up and management.

The mobile sleep medicine model in neurologic practice: Rationale and application

Background

Undiagnosed obstructive sleep apnea (OSA) is prevalent in neurological practice and significantly contributes to morbidity and mortality. OSA is prevalent in US adults and causes poor quality sleep and significant neurocognitive, cardiovascular, and cerebrovascular impairments. Timely treatment of OSA reduces cardio-cerebrovascular risks and improves quality of life. However, most of the US population has limited systematic access to sleep medicine care despite its clinical significance.

Focus

We discuss the importance of systematic screening, testing, and best-practice management of OSA and hypoventilation/hypoxemia syndromes (HHS) in patients with stroke, neurocognitive impairment, and neuromuscular conditions. This review aims to introduce and describe a novel integrated Mobile Sleep Medicine (iMSM) care model and provide the rationale for using an iMSM in general neurological practice to assist with systematic screening, testing and best-practice management of OSA, HHS, and potentially other sleep conditions.

Key points

The iMSM is an innovative, patient-centered, clinical outcome-based program that uses a Mobile Sleep Medicine Unit—a “sleep lab on wheels”—designed to improve access to OSA management and sleep care at all levels of health care system. The protocol for the iMSM care model includes three levels of operations to provide effective and efficient OSA screening, timely testing/treatment plans, and coordination of further sleep medicine care follow-up. The iMSM care model prioritizes effective, efficient, and patient-centered sleep medicine care; therefore, all parties and segments of care that receive and provide clinical sleep medicine services may benefit from adopting this innovative approach.

High prevalence of obstructive sleep apnea syndrome in Spain's Stroke Belt

Objective

Spain’s so-called Stroke Belt is an area with high prevalence of vascular disease. We aimed to determine the prevalence of undetected obstructive sleep apnea–hypopnea syndrome (OSAHS) among patients with acute ischemic stroke (AIS) in southern Spain.

Methods

We conducted a cross-sectional study at the Virgen Macarena University Hospital Stroke Unit during 2018 to 2019. We included patients <72 hours after AIS with a neuroimaging lesion and performed sleep tests.

Results

Seventy-two patients were included. The median participant age was 72 years. Mean body mass index was 27.07 kg/m², and 40.28% were daily alcohol drinkers. Hypertension, atrial fibrillation, ischemic cardiomyopathy, and previous stroke were detected in 63.9%, 11.1%, 15.3%, and 17.6% of patients, respectively. Polygraphy was feasible in 91.38% of patients. The prevalence of OSAHS was 84.72% (apnea–hypopnea index ≥5). Patients with moderate and severe OSAHS were more likely to be obese and to have a larger neck circumference and facial palsy. The diagnostic criteria of central sleep apnea syndrome were met in only 1.38% of patients.

Conclusions

The high prevalence of OSAHS found in the Spanish Stroke Belt justifies further investigation and development of a screening program as a strategy to identify patients with undetected OSAHS.

Acute Stroke Patients with Sleep Apnea Acording to the Disability and Incidence of Relapse

BACKGROUND

Sleep is a complex process involving the interactions of several brain regions, which play a key role in regulating the sleep process, particularly the brainstem, thalamus, and anterior basal brain regions. The process of sleep is accompanied by a change in body functions, as well as a change in cerebral electrical activity, which is under the control of the autonomic nervous system.

OBJECTIVE

The aim of the study was to analyze the frequency of stroke recurrence and disability of patients with stroke and apnea.

METHODS

It was analyzed 110 acute stroke patients with sleep apnea. All patients were evaluated with: Glasgow scale, The American National Institutes of Health Scale Assessment, Mini Mental Test, The Sleep and snoring Questionnaire Test, The Berlin Questionnaire Test, The Epworth Sleepiness Scale, The Stanford Sleepiness Scale, and The general sleep questionnaire.

RESULTS

The largest number of patients with apnea on admission had a degree of disability of 4, and on discharge of 1. There was a statistically significant difference between the mean values of incapacity for admission and discharge. The student's t - test did not determine a statistically significant difference in disability according to the Rankin scale between patients with and without apnea at admission (t = 0.059, p = 0.95) and discharge (t = 0.71, p = 0.48). According to the NIHS scale, patients of both sexes with apnea had a neurological deficit of 7.55 ± 5.22 on admission and 7.1 ± 4.3 without apnea. Statistically significant difference was not found on the neurological deficit of both sexes, with and without apnea, at admission and discharge. With apnea, there were 13 relapses of stroke during one year, and without apnea in only 3 patients.

CONCLUSION

Patients with acute stroke have a significantly higher correlation rate according to sleep apnea. There is no significant correlation in the degree of disability between patients with and without apnea.

Wake-up strokes are linked to obstructive sleep apnea and worse early functional outcome

BACKGROUND AND AIMS

Presence of sleep-disordered breathing (SDB) and especially obstructive sleep apnea (OSA) is a known risk factor for ischemic stroke. Additionally, SDB effects negatively on recovery after stroke. Up to one fourth of strokes are present on awakening. The link between OSA and wake-up stroke (WUS) has been suggested. We aim to determine the association between OSA and WUS in a Finnish stroke unit cohort.

MATERIAL AND METHODS

An observational prospective longitudinal study consisted of 95 TIA (transient ischemic attack) and mild to moderate stroke patients referred to a Stroke Unit in Finland. Respiratory polygraphy was performed within 72 h of hospital admission. Patients were classified into WUS and non-WUS, and functional outcome measures (mRS, rehabilitation, hospitalization time) were collected. Functional outcomes and prevalence of OSA were compared between non-WUS and WUS.

RESULTS

OSA (AHI > 15/h) was more frequent among WUS than non-WUS (71% and 36%, respectively, p = 0.009). Functional outcome measured with mRS was worse in patients with WUS than non-WUS on registration day and at hospital discharge (p = 0.001). Need for rehabilitation in WUS was 43% of cases compared to 23% of non-WUS (p = 0.067). Hospitalization time was longer (5-15days) in 55% of WUS and 41% of non-WUS patients (p = 0.261).

CONCLUSION

Moderate-to-severe OSA is related to WUS compared to non-WUS. In addition, WUS have worse short-term outcomes measured in mRS. Further studies are needed to determine if OSA is causally linked to WUS.

Sleep apnea and stroke

PURPOSE OF REVIEW

Stroke and sleep apnea are highly prevalent conditions with a physiologically plausible bidirectional relationship. This review addresses prestroke sleep apnea, wake-up stroke and sleep apnea, and poststroke sleep apnea, with an attempt to highlight research published in the last 18 months.

RECENT FINDINGS

Sleep apnea is highly prevalent poststroke. Poststroke sleep apnea is associated with worse poststroke functional and cognitive outcomes and a higher risk of recurrent stroke. Physiologic tests are needed to diagnose sleep apnea in poststroke patients as sleep apnea questionnaires do not perform well in this population. The role of CPAP in poststroke management is not yet well established.

SUMMARY

Sleep apnea is a well established independent risk factor for stroke that confers an approximately two-fold increased risk of incident stroke. Sleep apnea is highly prevalent poststroke and is associated with worse outcomes after stroke. Sleep apnea is an attractive target for research addressing secondary stroke prevention and recovery.

Effect of early sleep apnoea treatment with adaptive servo-ventilation in acute stroke patients on cerebral lesion evolution and neurological outcomes: study protocol for a multicentre, randomized controlled, rater-blinded, clinical trial (eSATIS: early Sleep Apnoea Treatment in Stroke)

BACKGROUND

Sleep-disordered breathing (SDB) is highly prevalent in acute ischaemic stroke and is associated with worse functional outcome and increased risk of recurrence. Recent meta-analyses suggest the possibility of beneficial effects of nocturnal ventilatory treatments (continuous positive airway pressure (CPAP) or adaptive servo-ventilation (ASV)) in stroke patients with SDB. The evidence for a favourable effect of early SDB treatment in acute stroke patients remains, however, uncertain.

METHODS

eSATIS is an open-label, multicentre (6 centres in 4 countries), interventional, randomized controlled trial in patients with acute ischaemic stroke and significant SDB. Primary outcome of the study is the impact of immediate SDB treatment with non-invasive ASV on infarct progression measured with magnetic resonance imaging in the first 3 months after stroke. Secondary outcomes are the effects of immediate SDB treatment vs non-treatment on clinical outcome (independence in daily functioning, new cardio-/cerebrovascular events including death, cognition) and physiological parameters (blood pressure, endothelial functioning/arterial stiffness). After respiratory polygraphy in the first night after stroke, patients are classified as having significant SDB (apnoea-hypopnoea index (AHI) > 20/h) or no SDB (AHI < 5/h). Patients with significant SDB are randomized to treatment (ASV+ group) or no treatment (ASV- group) from the second night after stroke. In all patients, clinical, physiological and magnetic resonance imaging studies are performed between day 1 (visit 1) and days 4-7 (visit 4) and repeated at day 90 ± 7 (visit 6) after stroke.

DISCUSSION

The trial will give information on the feasibility and efficacy of ASV treatment in patients with acute stroke and SDB and allows assessing the impact of SDB on stroke outcome. Diagnosing and treating SDB during the acute phase of stroke is not yet current medical practice. Evidence in favour of ASV treatment from a randomized multicentre trial may lead to a change in stroke care and to improved outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02554487 , retrospectively registered on 16 September 2015 (actual study start date, 13 August 2015), and www.kofam.ch (SNCTP000001521).

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.

Sleep-disordered breathing in patients with stroke-induced dysphagia

This study examined the nature and characteristics of sleep-disordered breathing, including obstructive sleep apnea and central sleep apnea, in patients with post-stroke dysphagia, to determine the demographic, anthropometric and clinical variables that were associated with sleep-disordered breathing. Thirty-nine patients diagnosed with acute stroke (28 males and 11 females with a mean age of 72.3 ± 10.0 years) underwent overnight polysomnography (within 3.9 ± 1.6 days after admission). Sleep-disordered breathing was described by the apnea-hypopnea index and its obstructive and central components by the obstructive apnea-hypopnea index and central apnea-hypopnea index, respectively. Severity of dysphagia was assessed using the Mann Assessment of Swallowing Ability score. Severity of stroke and functional dependence were assessed by the National Institute of Health Stroke Scale and the modified Barthel index, respectively. Most of the cohort (87%) had moderate-to-severe dysphagia (Mann Assessment of Swallowing Ability of 143.2 ± 19.9). Sleep-disordered breathing (apnea-hypopnea index ≥ 5 events/hr) was present in 38 participants (97%) with a mean apnea-hypopnea index of 37.5 ± 24.4 events/hr. Sleep-disordered breathing was predominantly obstructive in nature, with a mean obstructive apnea-hypopnea index and central apnea-hypopnea index of 19.6 ± 15.7 and 11.4 ± 17.6 events/hr, respectively. Multivariate linear regression analyses showed that the apnea-hypopnea index was associated with sex (p = .0001), body mass index (p = .029) and the modified Barthel index (p = .006); the obstructive apnea-hypopnea index was associated with the Mann Assessment of Swallowing Ability (p = .006), sex (p = .004) and body mass index (p = .015) and had a nonlinear relationship with the modified Barthel index (p = .019); and the central apnea-hypopnea index was associated with sex (p = .027) and the modified Barthel index (p = .019). The present study showed that dysphagia severity was associated with obstructive sleep apnea severity and this association was independent of sex, modified Barthel index and body mass index. However, stroke-induced dysphagia was not associated with central sleep apnea or overall sleep-disordered breathing.

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.

SAS Care 1: sleep-disordered breathing in acute stroke an transient ischaemic attack - prevalence, evolution and association with functional outcome at 3 months, a prospective observational polysomnography study

Sleep-disordered breathing (SDB) is frequent in patients with acute stroke. Little is known, however about the evolution of SDB after stroke. Most of our knowledge stems from smaller cohort studies applying limited cardiopulmonary sleep recordings or from cross-sectional data collected in different populations.

This study aims to determine prevalence, type and intra-individual evolution of SDB based on full-night polysomnography (PSG) in acute stroke and 3 months thereafter. Furthermore, we aimed to identify predictors of SDB in the acute and chronic phase and to evaluate associations between SDB and functional outcome at 3 months (M3).

A total of 166 patients with acute cerebrovascular events were evaluated by full PSG at baseline and 105 again at M3. The baseline prevalence of SDB (apnoea–hypopnoea index (AHI)>5·h⁻¹) was 80.5% and 25.4% of the patients had severe SDB (AHI>30·h⁻¹). Obstructive sleep apnoea was more prevalent than central sleep apnoea (83.8% versus 13%). Mean±SD AHI was 21.4±17.6·h⁻¹and decreased significantly at M3 (18±16.4·h⁻¹; p=0.018). At M3, 91% of all patients with baseline SDB still had an AHI>5·h⁻¹ and in 68.1% the predominant type of SDB remained unchanged (78.9% in obstructive sleep apnoea and 44.4% in central sleep apnoea). The only predictors of SDB at baseline were higher age and body mass index and in the chronic phase additionally baseline AHI. Baseline AHI was associated with functional outcome (modified Rankin score >3) at M3.

The high prevalence of SDB in acute stroke, its persistence after 3 months, and the association with functional outcome supports the recommendation for a rapid SDB screening in stroke patients.

The high prevalence of SDB in acute stroke, its persistence after 3 months and its association with functional outcome support the recommendation for rapid SDB screening in stroke patientshttps://bit.ly/3bFWqV7

Prediction of sleep-disordered breathing after stroke

OBJECTIVE/BACKGROUND

Sleep-disordered breathing (SDB) is highly prevalent after stroke and is associated with poor outcomes. Currently, after stroke, objective testing must be used to differentiate patients with and without SDB. Within a large, population-based study, we evaluated the usefulness of a flexible statistical model based on baseline characteristics to predict post-stroke SDB.

PATIENTS/METHODS

Within a population-based study, participants (2010-2018) underwent SDB screening, shortly after ischemic stroke, with a home sleep apnea test. The respiratory event index (REI) was calculated as the number of apneas and hypopneas per hour of recording; values ≥10 defined SDB. The distributed random forest classifier (a machine learning technique) was applied to predict SDB with the following as predictors: demographics, stroke risk factors, stroke severity (NIHSS), neck and waist circumference, palate position, and pre-stroke symptoms of snoring, apneas, and sleepiness.

RESULTS

Within the total sample (n = 1330), median age was 65 years; 47% were women; 32% non-Hispanic white, 62% Mexican American, and 6% African American. SDB was found in 891 (67%). The area under the receiver operating characteristic curve, a measure of predictive ability, applied to the validation sample was 0.75 for the random forest model. Random forest correctly classified 72.5% of validation samples.

CONCLUSIONS

In this large, ethnically diverse, population-based sample of ischemic stroke patients, prediction models based on baseline characteristics and clinical measures showed fair rather than clinically reliable performance, even with use of advanced machine learning techniques. Results suggest that objective tests are still needed to differentiate ischemic stroke patients with and without SDB.

Association Between Risk of Obstructive Sleep Apnea and Cerebrovascular Reactivity in Stroke Patients

Background Obstructive sleep apnea (OSA) is present in 60% to 70% of stroke patients. Cerebral vasoreactivity in patients with stroke and OSA has not been well studied and could identify a new pathophysiologic mechanism with potential therapeutic intervention. We aimed to determine whether risk categories for OSA are associated with cerebral vasoreactivity in stroke patients. Methods and Results In this cross-sectional study of a cohort of patients with stroke, we used clinical questionnaires (Sleep Obstructive Apnea Score Optimized for Stroke [SOS] and snoring, tiredness, observed, pressure, bmi, age, neck, gender [STOP-BANG] scores) to assess the risk of OSA and transcranial Doppler to assess cerebral vasoreactivity (breath-holding index and visual evoked flow velocity response). Of the 99 patients included, 77 (78%) had medium or high risk of OSA and 80 performed transcranial Doppler. Mean breath-holding index was 0.52±0.37, and median visual evoked flow velocity response was 10.8% (interquartile range: 8.8-14.5); 54 of 78 (69%) showed impaired anterior circulation vasoreactivity (breath-holding index <0.69) and 53 of 71 (75%) showed impaired posterior circulation vasoreactivity (visual evoked flow velocity response ≤14.0%). There was a significant negative correlation between the risk of OSA calculated by STOP-BANG and the breath-holding index (r_S=-0.284, P=0.012). The following variables were associated with low anterior circulation vasoreactivity: dyslipidemia (odds ratio: 4.7; 95% CI, 1.5-14.2) and STOP-BANG score (odds ratio: 1.7 per 1-point increase; 95% CI, 1.1-1.5). Conclusions A high risk of OSA and impaired vasoreactivity exists in the population that has had stroke. Dyslipidemia and STOP-BANG sleep apnea risk categories were independently associated with impaired anterior circulation vasoreactivity.

A meta-analysis of continuous positive airway pressure therapy in prevention of cardiovascular events in patients with obstructive sleep apnoea

Aims

To assess whether continuous positive airway pressure (CPAP) therapy reduces major adverse cardiovascular events (MACE) in patients with moderate-to-severe obstructive sleep apnoea (OSA).

Methods and results

A total of 235 articles were recovered using MEDLINE, EMBASE and Cochrane library (inception-December 2016) and references contained in the identified articles. Seven randomized controlled trials (RCTs) were selected for final analysis. Analysis of 4268 patients demonstrated non-significant 26% relative risk reduction in MACE with CPAP [risk ratio (RR) 0.74; 95% confidence interval (CI) 0.47-1.17; P = 0.19, I2 = 48%]. A series of sensitivity analyses suggested that increased CPAP usage time yielded significant risk reduction in MACE. and stroke. Subgroup analysis revealed that CPAP adherence time ≥4 hours (h)/night reduced the risk of MACE by 57% (RR 0.43; 95% CI 0.23-0.80; P = 0.01, I2 = 0%). CPAP therapy showed no beneficial effect on myocardial infarction (MI), all-cause mortality, atrial fibrillation/flutter (AF), or heart failure (HF) (P > 0.05). CPAP had positive effect on mood and reduced the daytime sleepiness [Epworth Sleepiness Scale (ESS): mean difference (MD) -2.50, 95% CI - 3.62, -1.39; P < 0.001, I2 = 81%].

Conclusion

CPAP therapy might reduce MACE and stroke among subjects with CPAP time exceeding 4 h/night. Additional randomized trials mandating adequate CPAP time adherence are required to confirm this impression.

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.

Telemedicine Improves Continuous Positive Airway Pressure Adherence in Stroke Patients with Obstructive Sleep Apnea in a Randomized Trial

BACKGROUND

The prevalence of obstructive sleep apnea (OSA) is very high in stroke patients, whereas the acceptance of positive airway pressure (PAP) therapy is low. Although telemedicine offers new options to increase acceptance, effective concepts and patient groups are not yet known.

OBJECTIVE

The aim of this study was to investigate the effect of a telemedicine concept consisting of telemonitoring and support when usage time drops.

METHODS

PAP naive stroke patients with apnea-hypopnea index (AHI) >15 were randomized in a prospective parallel design comparing home therapy with standard care (SC) as opposed to telemedicine care (TC) over a period of 6 months. The TC group received a standardized phone call to offer help and advice if the average weekly usage of PAP fell below 4 h/night.

RESULTS

Eighty patients were included, 5 were lost to follow-up, 75 (20 females, age: 57.0 ± 9.9, body mass index: 30.9 ± 6.0 kg/m2, AHI: 39.4 ± 18.6) were evaluated. While inpatient usage was similar in both groups, a significant difference was identified after 6 months of receiving home therapy (TC: 4.4 ± 2.5 h, SC: 2.1 ± 2.2 h; p < 0.000063). On average, 4.7 ± 3.1 interventional phone calls were needed (173 calls in total, ranging from 0 to 10 calls per patient), primarily for the purpose of motivation (61.3%), mask problems (16.2%), nasopharyngeal complaints or humidification issues (11.2%), and technical questions (10.6%). Sleepiness (Epworth Sleepiness Scale [ESS]) differed significantly (TC: 3.7 + 3.2, SC: 6.1 + 4.1; p = 0.008), as well as systolic blood pressure, which was available in a subgroup of 55 patients (TC: 129.5 + 15.2 mm Hg, SC: 138.8 + 16.1 mm Hg; p = 0.034).

CONCLUSION

A concept of telemonitoring and short telephone calls from the sleep lab raised PAP therapy adherence significantly in a group of stroke patients with moderate to severe OSA.

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.

Routine low-dose continuous or nocturnal oxygen for people with acute stroke: three-arm Stroke Oxygen Supplementation RCT

BACKGROUND

Stroke is a major cause of death and disability worldwide. Hypoxia is common after stroke and is associated with worse outcomes. Oxygen supplementation could prevent hypoxia and secondary brain damage.

OBJECTIVES

(1) To assess whether or not routine low-dose oxygen supplementation in patients with acute stroke improves outcome compared with no oxygen; and (2) to assess whether or not oxygen given at night only, when oxygen saturation is most likely to be low, is more effective than continuous supplementation.

DESIGN

Multicentre, prospective, randomised, open, blinded-end point trial.

SETTING

Secondary care hospitals with acute stroke wards.

PARTICIPANTS

Adult stroke patients within 24 hours of hospital admission and 48 hours of stroke onset, without definite indications for or contraindications to oxygen or a life-threatening condition other than stroke.

INTERVENTIONS

Allocated by web-based minimised randomisation to: (1) continuous oxygen: oxygen via nasal cannula continuously (day and night) for 72 hours after randomisation at a flow rate of 3 l/minute if baseline oxygen saturation was ≤ 93% or 2 l/minute if > 93%; (2) nocturnal oxygen: oxygen via nasal cannula overnight (21:00-07:00) for three consecutive nights. The flow rate was the same as the continuous oxygen group; and (3) control: no routine oxygen supplementation unless required for reasons other than stroke.

MAIN OUTCOME MEASURES

Primary outcome: disability assessed by the modified Rankin Scale (mRS) at 3 months by postal questionnaire (participant aware, assessor blinded). Secondary outcomes at 7 days: neurological improvement, National Institutes of Health Stroke Scale (NIHSS), mortality, and the highest and lowest oxygen saturations within the first 72 hours. Secondary outcomes at 3, 6, and 12 months: mortality, independence, current living arrangements, Barthel Index, quality of life (European Quality of Life-5 Dimensions, three levels) and Nottingham Extended Activities of Daily Living scale by postal questionnaire.

RESULTS

In total, 8003 patients were recruited between 24 April 2008 and 17 June 2013 from 136 hospitals in the UK [continuous, n = 2668; nocturnal, n = 2667; control, n = 2668; mean age 72 years (standard deviation 13 years); 4398 (55%) males]. All prognostic factors and baseline characteristics were well matched across the groups. Eighty-two per cent had ischaemic strokes. At baseline the median Glasgow Coma Scale score was 15 (interquartile range 15-15) and the mean and median NIHSS scores were 7 and 5 (range 0-34), respectively. The mean oxygen saturation at randomisation was 96.6% in the continuous and nocturnal oxygen groups and 96.7% in the control group. Primary outcome: oxygen supplementation did not reduce disability in either the continuous or the nocturnal oxygen groups. The unadjusted odds ratio for a better outcome (lower mRS) was 0.97 [95% confidence interval (CI) 0.89 to 1.05; p = 0.5] for the combined oxygen groups (both continuous and nocturnal together) (n = 5152) versus the control (n = 2567) and 1.03 (95% CI 0.93 to 1.13; p = 0.6) for continuous versus nocturnal oxygen. Secondary outcomes: oxygen supplementation significantly increased oxygen saturation, but did not affect any of the other secondary outcomes.

LIMITATIONS

Severely hypoxic patients were not included.

CONCLUSIONS

Routine low-dose oxygen supplementation in stroke patients who are not severely hypoxic is safe, but does not improve outcome after stroke.

FUTURE WORK

To investigate the causes of hypoxia and develop methods of prevention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN52416964 and European Union Drug Regulating Authorities Clinical Trials (EudraCT) number 2006-003479-11.

FUNDING DETAILS

This project was funded by the National Institute for Health Research (NIHR) Research for Patient Benefit and Health Technology Assessment programmes and will be published in full in Health Technology Assessment; Vol. 22, No. 14. See the NIHR Journals Library website for further project information.

Microvascular cerebral blood flow fluctuations in association with apneas and hypopneas in acute ischemic stroke

In a pilot study on acute ischemic stroke (AIS) patients, unexpected periodic fluctuations in microvascular cerebral blood flow (CBF) had been observed. Motivated by the relative lack of information about the impact of the emergence of breathing disorders in association with stroke on cerebral hemodynamics, we hypothesized that these fluctuations are due to apneic and hypopneic events. A total of 28 patients were screened within the first week after stroke with a pulse oximeter. Five (18%) showed fluctuations of arterial blood oxygen saturation ( ≥ 3 % ) and were included in the study. Near-infrared diffuse correlation spectroscopy (DCS) was utilized bilaterally to measure the frontal lobe CBF alongside respiratory polygraphy. Biphasic CBF fluctuations were observed with a bilateral increase of 27.1 % ± 17.7 % and 29.0 % ± 17.4 % for the ipsilesional and contralesional hemispheres, respectively, and a decrease of - 19.3 % ± 9.1 % and - 21.0 % ± 8.9 % for the ipsilesional and contralesional hemispheres, respectively. The polygraph revealed that, in general, the fluctuations were associated with apneic and hypopneic events. This study motivates us to investigate whether the impact of altered respiratory patterns on cerebral hemodynamics can be detrimental in AIS patients.

Obstructive sleep apnoea and comorbidity - an overview of the association and impact of continuous positive airway pressure therapy

INTRODUCTION

Obstructive sleep apnoea (OSA) is highly prevalent and there is considerable evidence supporting an independent association with a wide range of co-morbidities including cardiovascular, endocrine and metabolic, neuropsychiatric, pulmonary, and renal. Areas covered: A PubMed search of all the recent literature relating to OSA and co-morbidities was undertaken to critically evaluate the potential relationships and possible benefit of continuous positive airway pressure (CPAP) therapy. Expert commentary: The evidence supporting an independent association is stronger for some co-morbidities than others and in cardiovascular diseases is strongest for hypertension and atrial fibrillation. Potential mechanisms include intermittent hypoxia, fluctuating intrathoracic pressure, and recurring micro-arousals that trigger cell and molecular consequences including sympathetic excitation, systemic inflammation and oxidative stress, in addition to metabolic and endothelial dysfunction. Different mechanisms may predominate in individual co-morbidities. Recent long term randomised controlled trials have cast doubt on benefits to co-morbidities from CPAP therapy of OSA, especially where co-morbidities are already established. However, benefits may result in patients who are compliant with therapy and further research is required to clearly establish the role of OSA therapy in both primary and secondary prevention of co-morbidities.

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.

[Sleep Disorders in Old Age]

Sleep Disorders in Old Age Abstract. Sleep disorders increase with age. Older patients rarely complain about sleep disorders, therefore it is important to ask about sleep problems. Insomnias, sleep-disordered breathing and restless legs syndrome tend to increase with older age. It is important to consider that sleep disorders may be the first symptom of a depression, anxiety disorder or neurodegenerative disorders such as dementias. Many factors can influence sleep in old age: it is important to inquire after sleeping habits including naps during the day, medication and comorbidity. Treatment depends on the causes. Insomnias should be treated mainly with non-pharmacological means such as cognitive behaviour therapy.

The Evolution of Sleep Apnea Six Months After Acute Ischemic Stroke and Thrombolysis

STUDY OBJECTIVES

Our goal was to investigate the evolution of prevalence, severity, and type of sleep apnea among patients who had an ischemic stroke, with or without treatment with thrombolysis after 6 months.

METHODS

We prospectively studied 204 patients who had an ischemic stroke (110 in the thrombolysis and 94 in the non-thrombolysis group). After follow-up, 177 patients were eligible for a final analysis (98 in the thrombolysis group and 79 in the non-thrombolysis group). An unattended sleep study with a three-channel portable device was performed both on admission and after the 6-month follow-up.

RESULTS

The patients receiving thrombolysis were younger than those in the non-thrombolysis group (mean 65.5 versus 69.6 years P = .039). Sleep apnea, defined as a respiratory event index (REI) ≥ 5 events/h, was diagnosed in 92.7% patients, 93.9% versus 91.1% (P = .488) in the thrombolysis and non-thrombolysis groups, respectively. The prevalence remained unchanged during follow-up. Mild sleep apnea progressed to moderate or severe sleep apnea in 69.2% of the patients. Globally, mean central apneas per hour increased by 2.2% (P = .002), whereas obstructive apneas declined by 1.7% (P = .014). The mean change of oxygen desaturation index was -6.1% (P < .001) in the thrombolysis group, -1.8% (P = .327) in the non-thrombolysis group, and 4.2% (P = .001) in the whole group. In the non-thrombolysis group, the risk for new sleep apnea incidence increased by 6.1-fold (P = .024) at follow-up when compared to the thrombolysis group.

CONCLUSIONS

Sleep apnea prevalence remained high in patients who had an ischemic stroke at 6 months post-stroke. The risk for developing sleep apnea after stroke was significantly lower among patients undergoing thrombolysis.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Title: Ischaemic Stroke and Sleep Apnea in Northern Part of Finland; Identifier: NCT01861275; URL: https://clinicaltrials.gov/ct2/show/NCT01861275.

[Long-term outcome prediction in patients with stroke]

AIM

To create a model to predict long-term stroke outcome using polysomnographic parameters.

MATERIAL AND METHODS

Authors prospectively enrolled 56 acute stroke patients. All subjects underwent clinical evaluation and polysomnographic study. A modified Rankin Scale was used to measure the degree of disability after stroke. Long-term stroke outcome was assessed 1 year post-stroke.

RESULTS AND CONCLUSION

REM-latency and apnea-hypopnea index are factors influencing long-term outcome of stroke. Including these parameters into the logistic regression model allows to predict stroke outcome at high levels of sensitivity and specificity.

Oropharyngeal Muscle Exercise Therapy Improves Signs and Symptoms of Post-stroke Moderate Obstructive Sleep Apnea Syndrome

The primary aim of the current study was to assess the effects of oropharingeal muscle exercises in obstruction severity on stroke patients with OSAS. The secondary aims were to evaluate the effects of the exercises on rehabilitation of neurological function, sleeping, and morphology change of upper airway. An open-label, single-blind, parallel-group, randomized, controlled trial was designed. Fifty post-stroke patients with moderate OSAS were randomly assigned into 2 groups (25 in each group). For the therapy group, oropharyngeal muscle exercise was performed during the daytime for 20 min, twice a day, for 6 weeks. The control group was subjected to sham therapy of deep breathing. Primary outcomes were the obstruction severity by polysomnography. Secondary outcomes included recovery of motor and neurocognitive function, personal activities of daily living assessment (ADL), sleep quality and sleepiness scale. It also included upper airway magnetic resonance imaging (MRI) measurements. Assessments were made at baseline and after 6-week exercise. Finally, 49 patients completed the study. The apnea–hypopnea index, snore index, arousal index, and minimum oxygen saturation improved after exercise (P < 0.05). Oropharyngeal muscle exercises improved subjective measurements of sleep quality (P = 0.017), daily sleepiness (P = 0.005), and performance (both P < 0.05) except for neurocognition (P = 0.741). The changes in obstruction improvement, sleep characteristics and performance scale were also associated with training time, as detected by Pearson's correlation analysis. The anatomic structural remodeling of the pharyngeal airway was measured using MRI, including the lager retropalatal distance (P = 0.018) and shorter length of soft palate (P = 0.044) compared with the baseline. Hence, oropharyngeal muscle exercise is a promising alternative treatment strategy for stroke patients with moderate OSAS.

Clinical Trial Registration:http://www.chictr.org.cn. Unique identifier: ChiCTR-IPR-16009970

Circadian rhythms may not influence the outcomes of thrombolysis in patients with ischemic stroke: A study from China

Circadian rhythms can affect physical or mental activities as well as the time of stroke onset. The impact of circadian rhythms on acute ischemic stroke (AIS) patients treated by recombinant alteplase (rt-PA) is still incongruent. This study aims to consider whether the outcomes of thrombolysis differ depending on stroke onset time and rt-PA infusion time in patients with AIS. A total of 447 AIS patients, who underwent rt-PA intravenous infusion within 4.5 hours after stroke onset, were enrolled in this study consecutively from June 2010 through December 2016. All of the patients were grouped based on the stroke onset time and rt-PA infusion time into two exact 12-hour intervals as daytime (06:01-18:00) and nighttime (18:01-06:00) and further divided into four subgroups at 6-hour time intervals (00:01-06:00, 06:01-12:00, 12:01-18:00 and 18:01-24:00). Major neurological improvement at 1 hour, 24 hours and 7 days, 7-day mortality rate and 24-hour hemorrhage transformation was recorded. The results showed that a total of 295 patients (66.4%) appeared with AIS and 252 (56.4%) were treated during daytime. Higher NIHSS at admission was observed when stroke occurred in nighttime, especially during 00:01-06:00. Patients with stroke onset in nighttime especially during 18:01-24:00 had a significant shorter onset-door time and onset-needle time. No differences of the major neurological improvement at 1 hour, 24 hours and 7 days, 24-hour hemorrhagic transformation and 7-day fatality rate were found among either 12-hour time frames or 6-hour time frames according to the time of stroke onset or rt-PA infusion. In conclusion, there was no evidence to predict that circadian rhythms could influence the outcomes of AIS patients treated with rt-PA in China, although stroke onset during nighttime might aggravate neurological impairment before treatment. Further, multicenter and prospective clinical trials with larger number of subjects are still needed to draw more reliable conclusions.

Factors Associated with Cheyne-Stokes Respiration in Acute Ischemic Stroke

Background and Purpose

Cheyne-Stokes respiration (CSR) is frequently observed in patients with acute stroke. There have been conflicting opinions about the associations of CSR with the location and size of the lesion. We aimed to better define the clinical relevance and pathogenesis of CSR in acute stroke.

Methods

We investigated patients who had been admitted with acute ischemic stroke and received an overnight sleep apnea test. We collected data on demographics, risk factors, etiologic subtypes, initial vital signs, clinical course of the stroke, and parameters associated with respiratory events during the sleep apnea test. We performed a multivariate logistic regression analysis to determine the factors associated with CSR.

Results

Among 182 patients, 35 patients showed CSR in sleep apnea testing. Large-artery atherosclerosis or cardioembolism, bilateral hemispheric involvement, atrial fibrillation, low left-ventricle ejection fraction (LVEF), and left atrium (LA) enlargement were all associated with the presence of CSR. Multivariate analysis revealed that the previous modified Rankin Scale (mRS) score, bilateral hemispheric involvement, low LVEF, and LA enlargement were significantly associated with CSR. Subgroup analysis with large-artery atherosclerosis without cardiac disease revealed that the previous mRS score is the only independent factor associated with CSR.

Conclusions

CSR frequently occurs in strokes involving large arteries or due to cardioembolism, regardless of the location and severity of the stroke. Predisposing conditions such as preexisting neurologic disability, low LVEF, and LA enlargement are associated with CSR in acute stroke.

High-Resolution Pulse Oximetry (HRPO): A Cost-Effective Tool in Screening for Obstructive Sleep Apnea (OSA) in Acute Stroke and Predicting Outcome

INTRODUCTION

Obstructive sleep apnea (OSA) is a well-known risk factor for stroke. This is attributed to multiple mechanisms such as endothelial dysfunction, atrial fibrillation, hypertension, and comorbid obesity. STOP questionnaire alone is unreliable to diagnose OSA and in-hospital sleep study is costly and can be technically challenging. We used high-resolution pulse oximetry (HRPO) to test the feasibility of screening for OSA and predicting outcome.

METHODS

Data from 115 stroke patients who underwent HRPO was collected including Oxygen desaturation index (ODI) <4%, pulse rate, arterial oxygen saturation (SaO₂), and time spent at SaO₂ saturation <88%. We also collected data on various confounders. The outcomes measured were NIHSS (National Institutes of Health Stroke Scale), mRS (modified Rankin Score) on discharge, and discharge disposition.

RESULTS

Overall 115 patients with valid HRPO data were included in the study. Mean age was 64±12years with 68% white, 22% black, and 10% Hispanic population. Of this cohort of 115 patients, 56% were males. Of the subjects enrolled 22 had atrial fibrillation, 27 had type 2 diabetes, 7 had resistant hypertension, and 7 had patient foramen ovale. Of the 115 patients, 75 patients were found to have ODI of >10 and the mean ODI was 29±30. The NIHSS on admission was 6.14±6.93 and on discharge was 4.46±4.59, mRS on discharge was 1.70±1.67 with 52% being discharged home, 43% to rehab, 2% nursing home, and 3% to long-term acute care facility. In this study, we show a strong association between atrial fibrillation and increasing ODI (P<.001, OR 1.01, CI 1.00-1.03). In addition, our study also shows an association between discharges outcome of rehab (more deficits leading to higher disability) versus discharge to home (lesser deficits) if ODI was ≤10 (P = 0.005, OR 3.76, CI 1.49-9.52).

CONCLUSIONS

Our study showed that there is a significant burden of OSA in acute stroke patients. ODI emerged as a predictor of atrial fibrillation and discharge disposition in our study. HRPO may be a cost-effective tool to screen and evaluate for OSA in acute stroke patients.

Lack of Worsening of Sleep-Disordered Breathing After Recurrent Stroke in the BASIC Project

STUDY OBJECTIVES

To investigate the difference in sleep-disordered breathing (SDB) prevalence and severity after an index and recurrent stroke.

METHODS

In a sample of 40 subjects, home sleep apnea tests were performed a median of 10 days after an index ischemic stroke and 14 days after a recurrent ischemic stroke. A respiratory event index (REI) of ≥ 10 events/h (apneas plus hypopneas per hour of recording) was used to define clinically significant SDB. The relative difference in REI or relative SDB prevalence was used to compare the post-recurrent stroke measurement with that made after the index stroke, and was expressed as a rate ratio (RR) or prevalence ratio (PR). Adjusted regression models (negative binomial for REI and log binomial for SDB) included change in body mass index and time between the events.

RESULTS

The median time from index to recurrent stroke was 330.5 days (interquartile range [IQR]: 103.5, 766.5). The median REI was 17.5 (IQR: 9.0, 32.0) after the index stroke and 18.0 (IQR: 11.0, 25.5) after the recurrent stroke. The within-subject median difference was zero (IQR: -9, 7.5). The relative difference in REI was not significant in unadjusted or adjusted (RR: 0.97 [95% confidence interval: 0.76, 1.24]) models. The prevalence of SDB was not different after the recurrent stroke compared with the index stroke, in unadjusted or adjusted (PR: 1.10 [95% confidence interval: 0.91, 1.32]) models.

CONCLUSIONS

In this within-subject, longitudinal study, neither severity nor prevalence of SDB worsened after recurrent stroke.

Prevalence, Risk Factors, Outcomes, and Treatment of Obstructive Sleep Apnea in Patients with Cerebrovascular Disease: A Systematic Review

BACKGROUND

Obstructive sleep apnea (OSA) is known to increase the risk of cerebrovascular disease (CVD), and patients with CVD have high incidence of OSA. The study aimed to systematically evaluate the prevalence of OSA in patients with CVD.

MATERIALS AND METHODS

Medline, Embase, Science Citation Index, Wanfang, CNKI, and Wiley Online Library were thoroughly searched to identify relevant studies. Random-effects models were used to calculate the pooled rate estimates. Meta-regression and subgroup analysis were performed to explore potential sources of heterogeneity.

RESULTS

Thirty-seven studies with 3242 patients were analyzed. The prevalence of OSA (apnea hypopnea index [AHI] >10) ranged from 34.5% to 92.3%, the random-effects pooled prevalence was 61.9%. Furthermore, the prevalence of sleep disordered breathing (SDB) with AHI  greater than  5 was 70.4%, with AHI greater than 20 was 39.5%, and with AHI greater than 30 was 30.1%. Only 8.3% of the SDB was primarily central apnea. Seventeen studies reported risk factors for OSA, 6 of which used multivariate analyses to extract risk factors. In univariate meta-regression analysis, male had higher prevalence than female (P = .041). OSA was associated with increased length of hospitalization in 2 studies, and 1 long-term study reported severe sleep apnea was associated with poor functional outcome. Among the 5 studies on treatment, 3 indicated that early treatment with CPAP was effective; the remaining studies did not find benefit from CPAP treatment and reported the CPAP acceptance was poor.

CONCLUSIONS

There is high prevalence of OSA in patients with CVD (61.9%). Therefore, accurate diagnosis and treatment to OSA is very important so as to prevent CVD.

Sex differences in sleep-disordered breathing after stroke: results from the BASIC project

OBJECTIVE/BACKGROUND

Sleep-disordered breathing (SDB), an independent risk factor for stroke, is associated with worse post-stroke outcomes. Differences in the relationship between SDB and stroke may exist for women versus men. In this population-based study, we compared the prevalence of both pre- and post-stroke SDB by sex. We also explored whether menopausal status is related to post-stroke SDB.

PATIENTS/METHODS

We performed a cross-sectional study of subjects enrolled in the Brain Attack Surveillance in Corpus Christi (BASIC) project. Each subject (n = 1815) underwent a baseline interview including the Berlin Questionnaire to assess pre-stroke SDB risk and, if relevant, questions regarding menopausal status. Subjects were offered overnight SDB screening with a validated portable respiratory device (n = 832 with complete data). Log Poisson and linear regression models were used to assess the differences in SDB between men and women with adjustment for demographics, stroke risk factors, stroke severity, and other potential confounders.

RESULTS

Women were less likely than men to be at high risk for pre-stroke SDB (56.6% versus 61.9%) (prevalence ratio [PR] 0.87 for women; 95% confidence interval [CI], 0.81-0.95). A lower proportion of women than men (50.8% versus 70.2%) had post-stroke SDB by respiratory monitoring (PR 0.71; 95% CI, 0.63-0.80). SDB severity was higher for men than for women (mean difference in respiratory event index [REI] 6.5; 95% CI, 4.3-8.7). No significant association existed between post-stroke SDB and either menopausal status or age at menopause.

CONCLUSIONS

After acute ischemic stroke, SDB was more prevalent and more severe in men than in women.

Nocturnal Desaturation is Associated With Neurological Deterioration Following Ischemic Stroke: A Retrospective Observational Study

STUDY OBJECTIVES

The mechanism of early neurological deterioration (END) in patients with stroke remains unclear. We assessed the relationship between nocturnal oxygen desaturation (NOD) in the stroke unit (SU) and END, especially occurring at nighttime, following acute stroke.

METHODS

A retrospective analysis was performed on a total of 276 patients with ischemic stroke who were admitted to the SU between July 2013 and June 2015. The oxygen desaturation index was calculated from pulse oximetry data sampled every 1 minute during 9 hours on the first night (10:00 PM to 7:00 AM) after admission, and NOD was defined as oxygen desaturation index ≥ 5 events/h. END was defined as an increase of ≥ 2 points from the baseline National Institutes of Health Stroke Scale during 7 days after onset. We compared clinical characteristics and NOD between patients with and without END.

RESULTS

Among the included patients (mean age 69.2; male 55.4%), 42 patients (15.2%) experienced END. The proportion of NOD was significantly greater in the END group (45.2% versus 12.8%, P < .001). After adjusting for confounders, NOD was independently associated with END (odds ratio 7.57; 95% confidence interval 3.14-18.27). Among END patients, 47.6% patients (n = 20) had END during nighttime. Moreover, NOD was more frequent in patients with END during nighttime compared to those with END during daytime (73.7% versus 26.1%, P = .002).

CONCLUSIONS

NOD in the SU was associated with END, especially during nighttime, after ischemic stroke. This suggests that treatment of sleep-disordered breathing could be a modifiable factor to possibly reduce the risk of neurological worsening among acute stroke patients.

Diagnosing and managing sleep apnea in patients with chronic cerebrovascular disease: a randomized trial of a home-based strategy

BACKGROUND

Obstructive sleep apnea is common and associated with poor outcomes after stroke or transient ischemic attack (TIA). We sought to determine whether the intervention strategy improved sleep apnea detection, obstructive sleep apnea (OSA) treatment, and hypertension control among patients with chronic cerebrovascular disease and hypertension.

METHODS

In this randomized controlled strategy trial intervention, patients received unattended polysomnography at baseline, and patients with OSA (apnea-hypopnea index ≥5 events/h) received auto-titrating continuous positive airway pressure (CPAP) for up to 1 year. Control patients received usual care and unattended polysomnography at the end of the study, to identify undiagnosed OSA. Both groups received 24-h blood pressure assessments at baseline and end of the study. "Excellent" CPAP adherence was defined as cumulative use of ≥4 h/night for ≥70% of the nights.

RESULTS

Among 225 randomized patients (115 control; 110 intervention), 61.9% (120/194) had sleep apnea. The strategy successfully diagnosed sleep apnea with 97.1% (102/105) valid studies; 90.6% (48/53, 95% CI 82.7-98.4%) of sleep apnea was undiagnosed among control patients. The intervention improved long-term excellent CPAP use: 38.6% (22/57) intervention versus 0% (0/2) control (p < 0.0001). The intervention did not improve hypertension control in this population with well-controlled baseline blood pressure: intervention, 132.7 mmHg (±standard deviation, 14.1) versus control, 133.8 mmHg (±14.0) (adjusted difference, -1.1 mmHg, 95% CI (-4.2, 2.0)), p = 0.48).

CONCLUSIONS

Patients with cerebrovascular disease and hypertension have a high prevalence of OSA. The use of portable polysomnography, and auto-titrating CPAP in the patients' homes, improved both the diagnosis and the treatment for sleep apnea compared with usual care but did not lower blood pressure.

Study of association of severity of sleep disordered breathing and functional outcome in stroke patients

OBJECTIVE

Sleep disordered breathing (SDB) is a prevalent yet underrecognized condition that may have major adverse consequences for those affected by it. We performed a prospective observational study to seek a correlation of severity of SDB with the severity of stroke and its functional outcome.

METHODS

Patients with history of recent-onset stroke were recruited and underwent overnight polysomnography (PSG) after the acute phase of the stroke was over; for defining hypopneas, 3% and 4% desaturation limits were used, and the apnea-hypopnea index was respectively calculated as AHI_3% and AHI_4%. Stroke severity was graded using the Scandinavian Stroke Scale. Functional disability and neurological impairment was evaluated six weeks after the PSG using the Barthel Index (<80 = functional dependence; ≥80 = functional independence) and modified Rankins Scale (>2 = poor outcome; ≤2 = good outcome).

RESULTS

A total of 50 patients were enrolled, 30 (60%) with ischemic stroke and 20 (40%) with hemorrhagic strokes. Of the patients, 39 (78%) had an AHI_4% of >5/h, 23 (46%) had an AHI_4% of >15/h, and 9 (18%) had an AHI_4% of >30/h. Multivariate analysis showed that body mass index (odds ratio [OR] = 1.26; 95% confidence interval [CI] = 1.04-1.54, p = 0.019) and Scandinavian Stroke Scale score (stroke severity) (OR = 0.86; 95% CI = 0.76-0.96, p = 0.009) were significant risk factors for predicting SDB (AHI_4% > 15) in patients of stroke. When we looked for factors predicting outcomes, only AHI_4% (OR = 1.20; 95% CI 1.01-1.43, p value 0.041) was predictive of the functional dependence (based on Barthel Index) of the patient and AHI_4% (OR = 1.14; 95% CI 1.03-1.25, p = 0.008) and body mass index (OR = 0.75; 95% CI 0.59-0.96, p = 0.024) were found to be predictive of poor outcome (based on modified Rankins Scale). We obtained similar results, regardless of the hypopnea definition used.

CONCLUSION

In conclusion, given the high frequency of SDB in stroke patients and its correlation with poor outcome, screening for obstructive sleep apnea in all stroke and transient ischemic attack patients may be warranted.

Rehabilitation of Cardiovascular Disorders and Sleep Apnea

Obstructive sleep apnea (OSA) is present in more than 50% of patients referred to cardiac rehabilitation units. However, it has been under-recognized in patients after stroke and heart failure. Those with concurrent OSA have a worse clinical course. Early treatment of coexisting OSA with continuous positive airway pressure (CPAP) results in improved rehabilitation outcomes and quality of life. Possible mechanisms by which CPAP may improve recovery include decreased blood pressure fluctuations associated with apneas, and improved left ventricular function, cerebral blood flow, and oxygenation. Early screening and treatment of OSA should be integral components of patients entering cardiac rehabilitation units.

Spontaneous improvement in both obstructive sleep apnea and cognitive impairment after stroke

BACKGROUND

Knowledge available about the relationship between obstructive sleep apnea (OSA) and cognitive impairment after stroke is limited. The evolution of OSA and cognitive performance after stroke is not sufficiently described.

METHODS

We prospectively enrolled and examined acute stroke patients without previously diagnosed OSA. The following information was collected: (1) demographics, (2) sleep cardio-respiratory polygraphy (PG) at 72 h, day seven, month three, and month 12 after stroke, (3) post-stroke functional disability tests at entry and at months three and 12, and (4) cognition (attention and orientation, memory, verbal fluency, language, and visual-spatial abilities) using the revised Addenbrooke's Cognitive Examination (ACE-R) at months three and 12.

RESULTS

Of 68 patients completing the study, OSA was diagnosed in 42 (61.8%) patients. The mean apnea/hypopnea index (AHI) at study entry of 21.0 ± 13.7 spontaneously declined to 11.6 ± 11.2 at month 12 in the OSA group (p < 0.0005). The total ACE-R score was significantly reduced at months three (p = 0.005) and 12 (p = 0.004) in the OSA group. Poorer performance on the subtests of memory at months 3 (p = 0.039) and 12 (p = 0.040) and verbal fluency at months 3 (p < 0.005) and 12 (p < 0.005) were observed in the OSA group compared to non-OSA group. Visual-spatial abilities in both the OSA (p = 0.001) and non-OSA (p = 0.046) groups and the total ACE-R score in the OSA (p = 0.005) and non-OSA (p = 0.002) groups improved.

CONCLUSIONS

A high prevalence of OSA and cognitive decline were present in patients after an acute stroke. Spontaneous improvements in both OSA and cognitive impairment were observed.

Airway management and mechanical ventilation in acute brain injury

Patients with acute neurologic disease often develop respiratory failure, the management of which profoundly affects brain physiology and long-term functional outcomes. This chapter reviews airway management and mechanical ventilation of patients with acute brain injury, offering practical strategies to optimize treatment of respiratory failure and minimize secondary brain injury. Specific concerns that are addressed include physiologic changes during intubation and ventilation such as the effects on intracranial pressure and brain perfusion; cervical spine management during endotracheal intubation; the role of tracheostomy; and how ventilation and oxygenation are utilized to minimize ischemia-reperfusion injury and cerebral metabolic distress.

Sleep apnoea and stroke

Sleep disorders have been known to physicians for a long time. In his famous aphorisms, Hippocrates said “Sleep or watchfulness exceeding that which is customary, augurs unfavorably”. Modern medicine has been able to disentangle some of the phenomena that disturb sleep. Among the most notable offenders is sleep apnoea that has gained prominence in the past few decades. It is being proposed as one of the potentially modifiable risk factors for vascular diseases including stroke. The pathological mechanisms linking sleep apnoea to vascular risk factors include hypoxia, cardiac arrhythmias, dysautonomia, impaired glucose tolerance, hypertension, dyslipidaemia and inflammation. In this article, we review literature linking sleep apnoea and stroke, including sleep apnoea as a risk factor for primary prevention with the potential to improve outcome after acute stroke and as a secondary risk factor, amenable to modification and hence vascular risk reduction.