The role of sleep in recovery following ischemic stroke: A review of human and animal data

Exercise-with-melatonin therapy improves sleep disorder and motor dysfunction in a rat model of ischemic stroke

JOURNAL/nrgr/04.03/01300535-202406000-00038/inline-graphic1/v/2023-10-30T152229Z/r/image-tiff

Exercise-with-melatonin therapy has complementary and synergistic effects on spinal cord injury and Alzheimer’s disease, but its effect on stroke is still poorly understood. In this study, we established a rat model of ischemic stroke by occluding the middle cerebral artery for 60 minutes. We treated the rats with exercise and melatonin therapy for 7 consecutive days. Results showed that exercise-with-melatonin therapy significantly prolonged sleep duration in the model rats, increased delta power values, and regularized delta power rhythm. Additionally, exercise-with-melatonin therapy improved coordination, endurance, and grip strength, as well as learning and memory abilities. At the same time, it led to higher hippocampal CA1 neuron activity and postsynaptic density thickness and lower expression of glutamate receptor 2 than did exercise or melatonin therapy alone. These findings suggest that exercise-with-melatonin therapy can alleviate sleep disorder and motor dysfunction by increasing glutamate receptor 2 protein expression and regulating hippocampal CA1 synaptic plasticity.

Do changes in beliefs and behaviours moderate improvement in insomnia after acquired brain injury?

Key mechanisms of change in cognitive behavioural therapy for insomnia in the general population encompass changing sleep-related beliefs and behaviours. In a population with acquired brain injury, cognitive behavioural therapy for insomnia is effective as well, but little is known about the mechanisms of change. The aim of this study was to evaluate how changing sleep-related beliefs and behaviours were associated with improvement in insomnia following blended cognitive behavioural therapy for insomnia in a population with acquired brain injury. A secondary analysis was performed on data of a randomized-controlled trial, including 24 participants that received blended cognitive behavioural therapy for insomnia, and 24 participants that received treatment as usual. Results showed that following blended cognitive behavioural therapy for insomnia, significantly more participants improved on dysfunctional beliefs and sleep-related behaviours and this was associated to improvement in insomnia severity. For sleep-related behaviours, the association between improvement on behaviour and improvement on insomnia was significantly moderated by blended cognitive behavioural therapy for insomnia. However, the relation between dysfunctional beliefs and insomnia was not moderated by type of treatment. Similar results were found for acquired brain injury-adapted versions of the questionnaires in which up to half of the items were excluded as they could be regarded as not dysfunctional for people with acquired brain injury. These results show that improvement on insomnia severity is related to improvement in dysfunctional beliefs and behaviours, and cognitive behavioural therapy for insomnia efficacy may be moderated by the improvement in behaviours in particular. A focus on these behaviours can enhance treatment efficacy, but caution is needed regarding the behaviours that may reflect adequate coping with the consequences of the acquired brain injury.

Disentangling neuroplasticity mechanisms in post-stroke language recovery

A major objective in post-stroke aphasia research is to gain a deeper understanding of neuroplastic mechanisms that drive language recovery, with the ultimate goal of enhancing treatment outcomes. Subsequent to recent advances in neuroimaging techniques, we now have the ability to examine more closely how neural activity patterns change after a stroke. However, the way these neural activity changes relate to language impairments and language recovery is still debated. The aim of this review is to provide a theoretical framework to better investigate and interpret neuroplasticity mechanisms underlying language recovery in post-stroke aphasia. We detail two sets of neuroplasticity mechanisms observed at the synaptic level that may explain functional neuroimaging findings in post-stroke aphasia recovery at the network level: feedback-based homeostatic plasticity and associative Hebbian plasticity. In conjunction with these plasticity mechanisms, higher-order cognitive control processes dynamically modulate neural activity in other regions to meet communication demands, despite reduced neural resources. This work provides a network-level neurobiological framework for understanding neural changes observed in post-stroke aphasia and can be used to define guidelines for personalized treatment development.

Up-to-date advance in the relationship between OSA and stroke: a narrative review

PURPOSE

Obstructive sleep apnea (OSA) and stroke affect each other. In this review, we summarized the effect of OSA on the onset and recurrence of stroke, the prognosis, and the treatment of poststroke patients with OSA.

METHODS

Pubmed/MEDLINE were searched through May 2023 to explore the relationship between OSA and stroke. The relevant papers included OSA and stroke, OSA and recurrent stroke, and the prognosis and treatment of poststroke patients with OSA.

RESULTS

The results showed that OSA can promote the onset and recurrence of stroke and that OSA may adversely affect the prognosis of poststroke patients. The application of continuous positive airway pressure (CPAP) and other treatments may benefit poststroke patients with OSA, though the long term effects of treatment are not well documented.

CONCLUSION

Both the onset and recurrence of stroke closely correlated with OSA, but the specific mechanisms remain unclear. Further studies should be carried out to explore effective treatments in patients with stroke and OSA.

Sleep and motor learning in stroke (SMiLES): a longitudinal study investigating sleep-dependent consolidation of motor sequence learning in the context of recovery after stroke

INTRODUCTION

There is growing evidence that sleep is disrupted after stroke, with worse sleep relating to poorer motor outcomes. It is also widely acknowledged that consolidation of motor learning, a critical component of poststroke recovery, is sleep-dependent. However, whether the relationship between disrupted sleep and poor outcomes after stroke is related to direct interference of sleep-dependent motor consolidation processes, is currently unknown. Therefore, the aim of the present study is to understand whether measures of motor consolidation mediate the relationship between sleep and clinical motor outcomes post stroke.

METHODS AND ANALYSIS

We will conduct a longitudinal observational study of up to 150 participants diagnosed with stroke affecting the upper limb. Participants will be recruited and assessed within 7 days of their stroke and followed up at approximately 1 and 6 months. The primary objective of the study is to determine whether sleep in the subacute phase of recovery explains the variability in upper limb motor outcomes after stroke (over and above predicted recovery potential from the Predict Recovery Potential algorithm) and whether this relationship is dependent on consolidation of motor learning. We will also test whether motor consolidation mediates the relationship between sleep and whole-body clinical motor outcomes, whether motor consolidation is associated with specific electrophysiological sleep signals and sleep alterations during subacute recovery.

ETHICS AND DISSEMINATION

This trial has received both Health Research Authority, Health and Care Research Wales and National Research Ethics Service approval (IRAS: 304135; REC: 22/LO/0353). The results of this trial will help to enhance our understanding of the role of sleep in recovery of motor function after stroke and will be disseminated via presentations at scientific conferences, peer-reviewed publication, public engagement events, stakeholder organisations and other forms of media where appropriate.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT05746260, registered on 27 February 2023.

Alleviating sleep disturbances and modulating neuronal activity after ischemia: Evidence for the benefits of zolpidem in stroke recovery

AIMS

Sleep disorders are prevalent among stroke survivors and impede stroke recovery, yet they are still insufficiently considered in the management of stroke patients, and the mechanisms by which they occur remain unclear. There is evidence that boosting phasic GABA signaling with zolpidem during the repair phase improves stroke recovery by enhancing neural plasticity; however, as a non-benzodiazepine hypnotic, the effects of zolpidem on post-stroke sleep disorders remain unclear.

METHOD

Transient ischemic stroke in male rats was induced with a 30-minute middle cerebral artery occlusion. Zolpidem or vehicle was intraperitoneally delivered once daily from 2 to 7 days after the stroke, and the electroencephalogram and electromyogram were recorded simultaneously. At 24 h after ischemia, c-Fos immunostaining was used to assess the effect of transient ischemic stroke and acute zolpidem treatment on neuronal activity.

RESULTS

In addition to the effects on reducing brain damage and mitigating behavioral deficits, repeated zolpidem treatment during the subacute phase of stroke quickly ameliorated circadian rhythm disruption, alleviated sleep fragmentation, and increased sleep depth in ischemic rats. Immunohistochemical staining showed that in contrast to robust activation in para-infarct and some remote areas by 24 h after the onset of focal ischemia, the activity of the ipsilateral suprachiasmatic nucleus, the biological rhythm center, was strongly suppressed. A single dose of zolpidem significantly upregulated c-Fos expression in the ipsilateral suprachiasmatic nucleus to levels comparable to the contralateral side.

CONCLUSION

Stroke leads to suprachiasmatic nucleus dysfunction. Zolpidem restores suprachiasmatic nucleus activity and effectively alleviates post-stroke sleep disturbances, indicating its potential to promote stroke recovery.

Effect of ventilation modalities on the early prognosis of patients with poststroke sleep apnea

OBJECTIVE

Continuous positive airway pressure (CPAP) is the primary modality for treating sleep apnea after acute ischemic stroke (AIS). However, not all patients are well adherent to CPAP. Finding an alternative modality of ventilation to CPAP is essential.

METHODS

This prospective randomized clinical trial was conducted from 1 May 2022 to 8 January 2023 at the Department of Neurology, Wuhan Union Hospital. Participants diagnosed with sleep apnea after AIS were grouped according to block randomization principles into the usual care group (nasal cannula and facemask), nasal continuous positive airway pressure (nCPAP) group, and high-flow nasal cannula (HFNC) group. Rates of pulmonary infection and endotracheal intubation within 1 week of hospitalization and 28-day mortality (poststroke) were the primary outcomes (early prognosis).

RESULTS

In the trial, 178 patients (119 males [66.85%]; mean [SD] age, 61.04 [11.78] years) were eventually enrolled in the usual care group (n = 63), the nCPAP group (n = 55), and the HFNC group (n = 60). After ventilation, the nCPAP and HFNC groups were more effective than the usual care group in reducing the rate of pulmonary infection, endotracheal intubation, and improving neurological function and sleep apnea severity. However, there was no difference in 28-day mortality. Additionally, the improvement in prognosis was consistent between nCPAP and HFNC. In the comparison of comfort, the HFNC group was superior to nCPAP.

INTERPRETATION

nCPAP and HFNC reduced early pulmonary infection rates and endotracheal intubation rates. For patients with poor compliance with nCPAP, HFNC may be the best alternative.

Targeting the blood-brain barrier to delay aging-accompanied neurological diseases by modulating gut microbiota, circadian rhythms, and their interplays

The blood-brain barrier (BBB) impairment plays a crucial role in the pathological processes of aging-accompanied neurological diseases (AAND). Meanwhile, circadian rhythms disruption and gut microbiota dysbiosis are associated with increased morbidity of neurological diseases in the accelerated aging population. Importantly, circadian rhythms disruption and gut microbiota dysbiosis are also known to induce the generation of toxic metabolites and pro-inflammatory cytokines, resulting in disruption of BBB integrity. Collectively, this provides a new perspective for exploring the relationship among circadian rhythms, gut microbes, and the BBB in aging-accompanied neurological diseases. In this review, we focus on recent advances in the interplay between circadian rhythm disturbances and gut microbiota dysbiosis, and their potential roles in the BBB disruption that occurs in AAND. Based on existing literature, we discuss and propose potential mechanisms underlying BBB damage induced by dysregulated circadian rhythms and gut microbiota, which would serve as the basis for developing potential interventions to protect the BBB in the aging population through targeting the BBB by exploiting its links with gut microbiota and circadian rhythms for treating AAND.

Can people with poststroke insomnia benefit from blended cognitive behavioral therapy? A single case experimental design

PURPOSE

Sleep is essential for our overall health and wellbeing. Unfortunately, stroke often induces insomnia, which has been shown to impede rehabilitation and recovery of function. Cognitive behavioral therapy for insomnia (CBT-I) is the treatment of choice for insomnia in the general population and is efficacious both when delivered face-to-face or online. The primary aim of this study was to evaluate efficacy of blended CBT-I (eCBT-I) in five poststroke participants with insomnia according to DSM-5 criteria.

METHODS

A randomized multiple baseline design was used to evaluate improvements in total sleep time, sleep onset latency, sleep efficiency, nocturnal awakenings and sleep quality. The intervention included six weeks of eCBT-I combined with two face-to-face sessions.

RESULTS

All participants completed the intervention. One participant stopped using the diary, while the other four completed it fully. All five sleep diary measures improved, significantly so for nocturnal awakenings. Moreover, after completion of the treatment, four out of five participants no longer fulfilled DSM-5 criteria for insomnia disorder.

CONCLUSIONS

This is the first study to show that blended CBT-I is potentially effective in participants with post-stroke insomnia. The findings justify extension to a randomized controlled trial.

Disturbed laterality of non-rapid eye movement sleep oscillations in post-stroke human sleep: a pilot study

Sleep is known to promote recovery post-stroke. However, there is a paucity of data profiling sleep oscillations in the post-stroke human brain. Recent rodent work showed that resurgence of physiologic spindles coupled to sleep slow oscillations (SOs) and concomitant decrease in pathological delta (δ) waves is associated with sustained motor performance gains during stroke recovery. The goal of this study was to evaluate bilaterality of non-rapid eye movement (NREM) sleep-oscillations (namely SOs, δ-waves, spindles, and their nesting) in post-stroke patients vs. healthy control subjects. We analyzed NREM-marked electroencephalography (EEG) data in hospitalized stroke-patients (n = 5) and healthy subjects (n = 3). We used a laterality index to evaluate symmetry of NREM oscillations across hemispheres. We found that stroke subjects had pronounced asymmetry in the oscillations, with a predominance of SOs, δ-waves, spindles, and nested spindles in affected hemisphere, when compared to the healthy subjects. Recent preclinical work classified SO-nested spindles as restorative post-stroke and δ-wave-nested spindles as pathological. We found that the ratio of SO-nested spindles laterality index to δ-wave-nested spindles laterality index was lower in stroke subjects. Using linear mixed models (which included random effects of concurrent pharmacologic drugs), we found large and medium effect size for δ-wave nested spindle and SO-nested spindle, respectively. Our results in this pilot study indicate that considering laterality index of NREM oscillations might be a useful metric for assessing recovery post-stroke and that factoring in pharmacologic drugs may be important when targeting sleep modulation for neurorehabilitation post-stroke.

Post-Stroke Insomnia Increased the Risk of Cognitive Impairments: A Hospital-Based Retrospective Cohort Study

OBJECTIVES/BACKGROUND

Insomnia is a common sleep complaint among patients who had a stroke and has been recognized as an independent risk factor for cognitive impairment. However, the relationship between poststroke insomnia and cognitive impairment over time is under-researched. Therefore, we examined the association between poststroke insomnia and the risk of cognitive impairment.

PARTICIPANTS

Stroke participants who had a stroke and were 20 years and older.

METHODS

This multicenter hospital-based retrospective cohort study with a 13-year follow-up period (2004-2017). The diagnosis of stroke, insomnia, and cognitive impairment was based on the International Classification of Diseases. The study participants who experienced a stroke were divided into two cohorts: those who also had insomnia and those who did not have insomnia. A Cox proportional-hazards regression model was used.

RESULTS

A total of 1,775 patients with a mean age of 67.6 years were included. Of these patients, 146 and 75 patients were diagnosed with insomnia and cognitive impairment during the follow-up period, respectively. The cumulative incidence of cognitive impairment in the stroke with insomnia cohort was significantly lower than that in the stroke without insomnia cohort (log-rank test, P < .001). The adjusted hazard ratio and 95% confidence interval (CI) of the stroke with insomnia cohort indicated a higher risk of cognitive impairment compared with the stroke without insomnia cohort (adjusted hazard ratio: 2.38; 95% CI: 1.41-4.03).

CONCLUSIONS

Patients who had a stroke and were diagnosed with insomnia exhibited a substantial increased risk of cognitive impairment over time.

Disturbed laterality of non-rapid eye movement sleep oscillations in post-stroke human sleep: a pilot study

Sleep is known to promote recovery post-stroke. However, there is a paucity of data profiling sleep oscillations post-stroke in the human brain. Recent rodent work showed that resurgence of physiologic spindles coupled to sleep slow oscillations(SOs) and concomitant decrease in pathological delta(δ) waves is associated with sustained motor performance gains during stroke recovery. The goal of this study was to evaluate bilaterality of non-rapid eye movement (NREM) sleep-oscillations (namely SOs, δ-waves, spindles and their nesting) in post-stroke patients versus healthy control subjects. We analyzed NREM-marked electroencephalography (EEG) data in hospitalized stroke-patients (n=5) and healthy subjects (n=3) from an open-sourced dataset. We used a laterality index to evaluate symmetry of NREM oscillations across hemispheres. We found that stroke subjects had pronounced asymmetry in the oscillations, with a predominance of SOs, δ-waves, spindles and nested spindles in one hemisphere, when compared to the healthy subjects. Recent preclinical work classified SO-nested spindles as restorative post-stroke and δ-wave-nested spindles as pathological. We found that the ratio of SO-nested spindles laterality index to δ-wave-nested spindles laterality index was lower in stroke subjects. Using linear mixed models (which included random effects of concurrent pharmacologic drugs), we found large and medium effect size for δ-wave nested spindle and SO-nested spindle, respectively. Our results indicate considering laterality index of NREM oscillations might be a useful metric for assessing recovery post-stroke and that factoring in pharmacologic drugs may be important when targeting sleep modulation for neurorehabilitation post-stroke.

The multifaceted aspects of sleep and sleep-wake disorders following stroke

Sleep-wake disorders (SWD) are acknowledged risk factors for both ischemic stroke and poor cardiovascular and functional outcome after stroke. SWD are frequent following stroke, with sleep apnea (SA) being the most frequent SWD affecting more than half of stroke survivors. While sleep disturbances and SWD are frequently reported in the acute phase, they may persist in the chronic phase after an ischemic stroke. Despite the frequency and risk associated with SWD following stroke, screening for SWD remains rare in the clinical setting, due to challenges in the assessment of post-stroke SWD, uncertainty regarding the optimal timing for their diagnosis, and a lack of clear treatment guidelines (i.e., when to treat and the optimal treatment strategy). However, little evidence support the feasibility of SWD treatment even in the acute phase of stroke and its favorable effect on long-term cardiovascular and functional outcomes. Thus, sleep health recommendations and SWD treatment should be systematically embedded in secondary stroke prevention strategy. We therefore propose that the management of SWD associated with stroke should rely on a multidisciplinary approach, with an integrated diagnostic, treatment, and follow-up strategy. The challenges in the field are to improve post-stroke SWD diagnosis, prognosis and treatment, through a better appraisal of their pathophysiology and temporal evolution.

The Diagnostic Value of Gut Microbiota Analysis for Post-Stroke Sleep Disorders

BACKGROUND

Gut microbiota have been associated with many psychiatric disorders. However, the changes in the composition of gut microbiota in patients with post-stroke sleep disorders (PSSDs) remain unclear. Here, we determined the gut microbial signature of PSSD patients.

METHODS

Fecal samples of 205 patients with ischemic stroke were collected within 24 h of admission and were further analyzed using 16 s RNA gene sequencing followed by bioinformatic analysis. The diversity, community composition, and differential microbes of gut microbiota were assessed. The outcome of sleep disorders was determined by the Pittsburgh Sleep Quality Index (PSQI) at 3 months after admission. The diagnostic performance of microbial characteristics in predicting PSSDs was assessed by receiver operating characteristic (ROC) curves.

RESULTS

Our results showed that the composition and structure of microbiota in patients with PSSDs were different from those without sleep disorders (PSNSDs). Moreover, the linear discriminant analysis effect size (LEfSe) showed significant differences in gut-associated bacteria, such as species of Streptococcus, Granulicatella, Dielma, Blautia, Paeniclostridium, and Sutterella. We further managed to identify the optimal microbiota signature and revealed that the predictive model with eight operational-taxonomic-unit-based biomarkers achieved a high accuracy in PSSD prediction (AUC = 0.768). Blautia and Streptococcus were considered to be the key microbiome signatures for patients with PSSD.

CONCLUSIONS

These findings indicated that a specific gut microbial signature was an important predictor of PSSDs, which highlighted the potential of microbiota as a promising biomarker for detecting PSSD patients.

The Importance of Sleep for Successful Neurorehabilitation after Stroke

Sleep has important clinical implications for neurorehabilitation after stroke. We aimed to systematically explore sleep (including naps) as an essential factor in the neurorehabilitation of patients after stroke. After titles and abstracts were screened, 49 full texts were reviewed, and 7 were included in this review. Data were extracted and assessed for quality and risk of bias. We looked at any neurorehabilitation setting, and compared sleep with no sleep and explored these factors in stroke patients versus healthy individuals. Rehabilitation is critical for many activities that may need to be learned or re-learned following stroke and for returning to everyday life. In this context, sleep is essential in neurorehabilitation and physical therapy practice as it supports neuroplasticity, memory, and learning. The available data suggest that sleep should be considered in the treatment plan for successfully targeted physiotherapy to optimize cognitive and motor learning. Physical therapists should advise about sleep hygiene and therapies to improve sleep, both quality and quantity.

The role of the physical environment in stroke recovery: Evidence-based design principles from a mixed-methods multiple case study

Hospital design can impact patient outcomes, but there is very little healthcare design evidence specific to stroke rehabilitation facilities. Our aim was to explore, from the patient perspective, the role of the physical environment in factors crucial to stroke recovery, namely, stroke survivor activity (physical, cognitive, social), sleep, emotional well-being, and safety. We conducted a mixed-methods multiple-case study at two inpatient rehabilitation facilities in Victoria, Australia, (n = 20 at Case 1, n = 16 at Case 2) using "walk-through" semi-structured interviews, behavioural mapping, questionnaires, and retrospective audit. Four interrelated themes emerged: 1) entrapment and escape; 2) power, dependency, and identity in an institutional environment; 3) the rehabilitation facility is a shared space; and 4) the environment should be legible and patient-centred. Quantitative data revealed patterns in patient activity; stroke survivors spent over 75% of their time in bedrooms and were often inactive. Convergent mixed methods analysis was used to generate a new conceptual model of the role of the physical environment in stroke survivors' behaviour and well-being, highlighting the importance of variety and interest, privacy without isolation, and patient-centred design. This model can be used by designers, healthcare providers, and policy makers to inform the design of rehabilitation environments.

Sex Differences in 90-Day Functional Outcomes for Acute Ischemic Stroke Patients With Obstructive Sleep Apnea

Background Obstructive sleep apnea (OSA) is characterized by repeated episodes of either full or partial obstruction of the upper airway. OSA is an independent risk factor for acute ischemic stroke (AIS) and a contributor to other key risk factors. OSA may damage endothelial and brain tissues and worsen outcomes following AIS. We aimed to evaluate the impact of sex differences on 90-day functional outcomes following AIS in an OSA population, as measured by the modified Rankin Scale (mRS) score. Methodology We performed a retrospective study of patients with OSA and AIS from the Houston Methodist Hospital Outcomes-Based Prospective Endpoints in Stroke (HOPES) Registry from 2016 to 2022. Patients with charts that noted a diagnosis of OSA before AIS or within the 90 days following AIS were included. A multivariable logistic regression model was constructed adjusting for demographics, first admit National Institutes of Health Stroke Scale (NIHSS), and comorbidities on the binary outcome. The odds ratios (ORs) and 95% confidence intervals (CIs) were reported, providing likelihood estimates of a shift to higher mRS for a given comparison between females (reference category) and males. Statistical significance was defined as two-tailed p-values <0.05 for all tests. Results From the HOPES registry, 291 females and 449 males were found to have OSA. Males had a higher proportion of comorbid conditions such as atrial fibrillation (15% vs. 9%, p = 0.014) and intracranial hemorrhage compared to females (6% vs. 2%, p = 0.020). The multivariate logistic regression model showed that males were at two times higher risk for developing poor functional outcomes at 90 days (OR = 2.35, 95% CI = 1.06-5.19), p < 0.001). Conclusions Males were found to have two times higher risk for developing poor functional outcomes at 90 days. This may be due to more severe oxygen desaturation, increased susceptibility to oxidative stress, and greater frequency of full airway obstruction in males. Greater emphasis on early diagnosis and treatment of OSA may be necessary to reduce the disproportionate incidence of poor functional outcomes, particularly among apneic male stroke survivors.

Improving sleep and learning in rehabilitation after stroke, part 2 (INSPIRES2): study protocol for a home-based randomised control trial of digital cognitive behavioural therapy (dCBT) for insomnia

INTRODUCTION

Consolidation of motor skill learning, a key component of rehabilitation post-stroke, is known to be sleep dependent. However, disrupted sleep is highly prevalent after stroke and is often associated with poor motor recovery and quality of life. Previous research has shown that digital cognitive behavioural therapy (dCBT) for insomnia can be effective at improving sleep quality after stroke. Therefore, the aim of this trial is to evaluate the potential for sleep improvement using a dCBT programme, to improve rehabilitation outcomes after stroke.

METHODS AND ANALYSIS

We will conduct a parallel-arm randomised controlled trial of dCBT (Sleepio) versus treatment as usual among individuals following stroke affecting the upper limb. Up to 100 participants will be randomly allocated (2:1) into either the intervention (6-8 week dCBT) or control (continued treatment as usual) group. The primary outcome of the study will be change in insomnia symptoms pre to post intervention compared with treatment as usual. Secondary outcomes include improvement in overnight motor memory consolidation and sleep measures between intervention groups, correlations between changes in sleep behaviour and overnight motor memory consolidation in the dCBT group and changes in symptoms of depression and fatigue between the dCBT and control groups. Analysis of covariance models and correlations will be used to analyse data from the primary and secondary outcomes.

ETHICS AND DISSEMINATION

The study has received approval from the National Research Ethics Service (22/EM/0080), Health Research Authority (HRA) and Health and Care Research Wales (HCRW), IRAS ID: 306 291. The results of this trial will be disseminated via presentations at scientific conferences, peer-reviewed publication, public engagement events, stakeholder organisations and other forms of media where appropriate.

TRIAL REGISTRATION NUMBER

NCT05511285.

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

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

Sleep Quantity and Quality During Inpatient Rehabilitation After Stroke

OBJECTIVE

To identify sleep patterns and their association with recovery after stroke during inpatient rehabilitation, and to determine if clinical outcomes are different between participants demonstrating abnormal sleep patterns as compared to those with normal sleep patterns.

METHODS

Cohort study in which participants were undergoing inpatient rehabilitation after a stroke. Sleep quantity and quality was measured using an actigraph that participants wore for up to 7 nights during the first week of inpatient rehabilitation. Medicare Quality Indicators (GG code), Barthel Index, gait speed, and Berg balance scale were collected at admission and discharge. Participants were categorized into groups based on meeting or not meeting recommended sleep quantity and quality guidelines. Association between sleep patterns and outcomes were assessed using Pearson correlation and differences in outcomes and length of stay between participants who met or did not meet sleep quantity and quality guidelines were determined using independent sample t-test.

RESULTS

69 participants were in the study. Sleep quantity and quality was poor for all the participants. None of the participants met all the sleep quantity and quality guidelines. There were moderate to small associations (-0.42 to 0.22) between some sleep quantity and quality parameters and clinical outcomes. Participants who's sleep efficiency (SE) was <85% had a significantly longer length of stay compared to those who's SE was >=85% (17.4 vs. 21.5 days, p<0.05).

CONCLUSIONS

People with stroke undergoing inpatient rehabilitation have poor sleep quantity and quality. There is a small to moderate association between sleep patterns and clinical outcomes and participants with poor sleep quality had longer length of stay compared to those with good sleep quality. Further research is necessary to better understand the complex relationship between sleep and recovery after stroke.

IMPACT

Sleep is associated with functional recovery during inpatient rehabilitation after stroke.

Measuring Sleep Quality in the Hospital Environment with Wearable and Non-Wearable Devices in Adults with Stroke Undergoing Inpatient Rehabilitation

Sleep disturbances are common after stroke and may affect recovery and rehabilitation outcomes. Sleep monitoring in the hospital environment is not routine practice yet may offer insight into how the hospital environment influences post-stroke sleep quality while also enabling us to investigate the relationships between sleep quality and neuroplasticity, physical activity, fatigue levels, and recovery of functional independence while undergoing rehabilitation. Commonly used sleep monitoring devices can be expensive, which limits their use in clinical settings. Therefore, there is a need for low-cost methods to monitor sleep quality in hospital settings. This study compared a commonly used actigraphy sleep monitoring device with a low-cost commercial device. Eighteen adults with stroke wore the Philips Actiwatch to monitor sleep latency, sleep time, number of awakenings, time spent awake, and sleep efficiency. A sub-sample (n = 6) slept with the Withings Sleep Analyzer in situ, recording the same sleep parameters. Intraclass correlation coefficients and Bland-Altman plots indicated poor agreement between the devices. Usability issues and inconsistencies were reported between the objectively measured sleep parameters recorded by the Withings device compared with the Philips Actiwatch. While these findings suggest that low-cost devices are not suitable for use in a hospital environment, further investigations in larger cohorts of adults with stroke are needed to examine the utility and accuracy of off-the-shelf low-cost devices to monitor sleep quality in the hospital environment.

A blended eHealth intervention for insomnia following acquired brain injury: a randomised controlled trial

The high prevalence and severe consequences of poor sleep following acquired brain injury emphasises the need for an effective treatment. However, treatment studies are scarce. The present study evaluates the efficacy of blended online cognitive behavioural therapy for insomnia (eCBT-I) developed specifically for people with acquired brain injury. In a multicentre prospective, open-label, blinded end-point randomised clinical trial, 52 participants with insomnia and a history of a stroke or traumatic brain injury were randomised to 6 weeks of guided eCBT-I or treatment as usual, with a 6-week follow-up. The primary outcome measure was the change in insomnia severity between baseline and after treatment, measured with the Insomnia Severity Index. Results showed that insomnia severity improved significantly more with eCBT-I than with treatment as usual compared to baseline, both at post-treatment (mean [SEM] 4.0 [1.3] insomnia severity index points stronger decrease, d = 0.96, p < 0.003) and at follow-up (mean [SEM] 3.2 [1.5] insomnia severity index points, d = -0.78, p < 0.03). In conclusion, our randomised clinical trial shows that blended CBT is an effective treatment for insomnia, and feasible for people with acquired brain injury, regardless of cognitive and psychiatric complaints. Online treatment has major advantages in terms of availability and cost and may contribute to the successful implementation of insomnia treatment for people with acquired brain injuries.

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.

Asymmetry in sleep spindles and motor outcome in infants with unilateral brain injury

AIM

To determine whether interhemispheric difference in sleep spindles in infants with perinatal unilateral brain injury could link to a pathological network reorganization that underpins the development of unilateral cerebral palsy (CP).

METHOD

This was a multicentre retrospective study of 40 infants (19 females, 21 males) with unilateral brain injury. Sleep spindles were detected and quantified with an automated algorithm from electroencephalograph records performed at 2 months to 5 months of age. The clinical outcomes after 18 months were compared to spindle power asymmetry (SPA) between hemispheres in different brain regions.

RESULTS

We found a significantly increased SPA in infants who later developed unilateral CP (n=13, with the most robust interhemispheric difference seen in the central spindles. The best individual-level prediction of unilateral CP was seen in the centro-occipital spindles with an overall accuracy of 93%. An empiric cut-off level for SPA at 0.65 gave a positive predictive value of 100% and a negative predictive value of 93% for later development of unilateral CP.

INTERPRETATION

Our data suggest that automated analysis of interhemispheric SPA provides a potential biomarker of unilateral CP at a very early age. This holds promise for guiding the early diagnostic process in infants with a perinatally identified brain injury.

WHAT THIS PAPER ADDS

Unilateral perinatal brain injury may affect the development of electroencephalogram (EEG) sleep spindles. Interhemispheric asymmetry in sleep spindles can be quantified with automated EEG analysis. Spindle power asymmetry can be a potential biomarker of unilateral cerebral palsy.

Ischemic Stroke Disrupts Sleep Homeostasis in Middle-Aged Mice

Sleep disturbances, including insomnia and excessive daytime sleepiness, are highly prevalent in patients with ischemic stroke (IS), which severely impacts recovery and rehabilitation efforts. However, how IS induces sleep disturbances is unclear. Three experiments were performed on middle-aged C57BL/6J mice, instrumented with sleep recording electrodes and/or subjected to 1 h of middle cerebral artery (MCAO; Stroke group) or sham (Sham group) occlusion to induce IS. After 48 h of reperfusion (a) experiment 1 verified sensorimotor deficit (using Garcia scale) and infarction (using TTC staining) in this mouse model; (b) experiment 2 examined the effects of IS on the quality (sleep latency and NREM delta power) and quantity (duration) of sleep; and (c) experiment 3 determined the effects of IS on sleep homeostasis using sleep deprivation (SD) and recovery sleep (RS) paradigm. Stroke mice display (a) a significant correlation between sensorimotor deficit and cerebral infarction; (b) insomnia-like symptoms (increased sleep latency, reduced NREM duration and delta power) during the light (inactive) period and daytime sleepiness-like symptoms during the dark (active) period mimicking sleep in IS patients; and (c) impairments in the markers of sleep pressure (during SD) and sleep dissipation (during RS). Our results suggest that IS disrupts sleep homeostasis to cause sleep disturbances.

Validation Study of the Richards-Campbell Sleep Questionnaire in Patients with Acute Stroke

Sleep disorders are frequent in acute stroke. The Richards-Campbell Sleep Questionnaire (RCSQ) is a validated scale for the sleep assessment in intensive care unit. The aim of the present study is to validate RCSQ for use in patients with acute stroke. We performed a validation study by comparing the RCSQ with polysomnography (PSG), the standardized measure of sleep. Inclusion criteria were age ≥ 18 years and a radiologically confirmed diagnosis of stroke. Exclusion criteria were global aphasia, extreme severity of clinical conditions and inability to attend PSG. All patients underwent PSG in a stroke unit, the day after a subjective sleep assessment by means of the RCSQ. The RCSQ was compared with PSG parameters to assess the degree of concordance of the two measures. The cohort consisted of 36 patients. Mean RCSQ score was 61.5 ± 24.8. The total score of the RCSQ showed a good degree of concordance with the sleep efficiency index of PSG. Accuracy of the RCSQ was 70%, sensitivity 71% and specificity 68%. The RCSQ is a good tool for screening the sleep quality in the setting of a stroke unit. Therefore, it could be useful to select the patients who might beneficiate from an instrumental sleep evaluation.

Modulation of melatonin to the thalamic lesion-induced pain and comorbid sleep disturbance in the animal model of the central post-stroke hemorrhage

The devastating chronic central post stroke pain is associated with variety of comorbidities. Disrupted sleep is a severe comorbidity, causing an increase in the suicide rate, due to CPSP’s pain symptom. Melatonin is a well-known jet-lag compound, which helps in entrainment of sleep cycle. Accordingly, whether melatonin as a therapeutic measurement for the regulation of sleep disturbance related to central post stroke pain remains unclear. Exogenous melatonin administration entrained the disrupted 24 h circadian cycle, more effectively after 2 and 3 week of administration. The effect of melatonin was persisted on 4th week too, when melatonin administration was discontinued. Also, melatonin ameliorated the pain due to distorted sleep-activity behavior after melatonin administration for 3 weeks. The low levels of melatonin in blood plasma due to CPSP were restored after 3 weeks of melatonin administration. After 30 mg/kg melatonin administrations for 3 weeks, all the disrupted resting and activity behaviors were reduced during light and dark periods. The results suggested that melatonin significantly ameliorated CPSP’s pain symptoms and comorbid sleep disturbance showing in activity behavior.

Modulation of neural co-firing to enhance network transmission and improve motor function after stroke

Stroke is a leading cause of disability. While neurotechnology has shown promise for improving upper limb recovery after stroke, efficacy in clinical trials has been variable. Our central thesis is that to improve clinical translation, we need to develop a common neurophysiological framework for understanding how neurotechnology alters network activity. Our perspective discusses principles for how motor networks, both healthy and those recovering from stroke, subserve reach-to-grasp movements. We focus on neural processing at the resolution of single movements, the timescale at which neurotechnologies are applied, and discuss how this activity might drive long-term plasticity. We propose that future studies should focus on cross-area communication and bridging our understanding of timescales ranging from single trials within a session to across multiple sessions. We hope that this perspective establishes a combined path forward for preclinical and clinical research with the goal of more robust clinical translation of neurotechnology.

A systematic review and proposed conceptual model of sleep disturbances during pediatric hospitalizations

STUDY OBJECTIVES

The current review aims to examine factors that influence pediatric inpatient sleep and determine the effectiveness of sleep promotion interventions among hospitalized children.

METHODS

A systematic literature search was conducted across PubMed, PsycINFO, CINAHL, Cochrane Central, Web of Science, Embase, and Scopus databases. Studies included children with a mean age between 1 and 18 years old that either described factors affecting the sleep of children who are hospitalized on a non-intensive care unit or reported on sleep-related intervention outcomes. We conducted separate narrative reviews for each of the two aims and then synthesized findings from quantitative and qualitative studies across both aims.

RESULTS

Forty-five articles were included for review. Despite most sleep disturbances being attributed to environmental disruptions (e.g. noise, staff interruptions), most interventions targeted the child level using relaxation techniques. Although the majority of interventions were small pilot studies, preliminary findings appear to positively impact sleep duration. The Pediatric Inpatient Sleep Model was proposed to illustrate connections between sleep disturbances, factors influencing sleep, and existing intervention components.

CONCLUSIONS

Replication studies are needed, including larger-scale sleep promotion interventions among hospitalized children. Given the identification of environmental factors as the main cause of night wakings, environmental modifications are crucial. Additional research examining contributors to intraindividual variability in disrupted sleep patterns during hospitalizations as well as the consequences of these disturbances is warranted.

Effects of CPAP on Language Recovery in Post-Stroke Aphasia: A Review of Recent Literature

Obstructive sleep apnea is highly prevalent in the post-stroke population, and has been shown to affect cognitive, neurological, and functional status. Continuous positive airway pressure (CPAP) treatment is one of the most effective interventions for obstructive sleep apnea, but compliance is often low due to confounding effects of co-occurring conditions, side effects of treatment titration procedures, and individual patient personality characteristics, perceptions, and social factors. Current research suggests that CPAP treatment for obstructive sleep apnea is not associated with significant risk and can subsequently improve post-stroke motor and neurocognitive function. However, effects of CPAP treatment on post-stroke speech and language recovery remain unclear. Post-stroke communication disorders (e.g., aphasia, dysarthria, and apraxia) are also highly prevalent in this population. Knowledge of the potential positive impact of CPAP on language recovery could contribute to patients’ motivation to comply with CPAP treatment and provide incentive for speech-language pathologists to refer patients to sleep medicine specialists. In this review of the literature, we examine the question of what effect CPAP treatment may have on post-stroke speech and language function and recovery, as well as summarize the current knowledge on cognitive, neurological, and functional effects. While this review of the literature found CPAP to have varying effects on different cognitive domains, there was not sufficient evidence to determine effects on language recovery. Further research is necessary to determine the potential effects of CPAP treatment on speech and language recovery among stroke patients.

Recovery of consolidation after sleep following stroke-interaction of slow waves, spindles, and GABA

Sleep is known to promote recovery after stroke. Yet it remains unclear how stroke affects neural processing during sleep. Using an experimental stroke model in rats along with electrophysiological monitoring of neural firing and sleep microarchitecture, here we show that sleep processing is altered by stroke. We find that the precise coupling of spindles to global slow oscillations (SOs), a phenomenon that is known to be important for memory consolidation, is disrupted by a pathological increase in "isolated" local delta waves. The transition from this pathological to a physiological state-with increased spindle coupling to SO-is associated with sustained performance gains during recovery. Interestingly, post-injury sleep could be pushed toward a physiological state via a pharmacological reduction of tonic γ-aminobutyric acid (GABA). Together, our results suggest that sleep processing after stroke is impaired due to an increase in delta waves and that its restoration can be important for recovery.

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.

Sleep and Stroke: Opening Our Eyes to Current Knowledge of a Key Relationship

PURPOSE OF REVIEW

To elucidate the interconnection between sleep and stroke.

RECENT FINDINGS

Growing data support a bidirectional relationship between stroke and sleep. In particular, there is strong evidence that sleep-disordered breathing plays a pivotal role as risk factor and concur to worsening functional outcome. Conversely, for others sleep disorders (e.g., insomnia, restless legs syndrome, periodic limb movements of sleep, REM sleep behavior disorder), the evidence is weak. Moreover, sleep disturbances are highly prevalent also in chronic stroke and concur to worsening quality of life of patients. Promising novel technologies will probably allow, in a near future, to guarantee a screening of commonest sleep disturbances in a larger proportion of patients with stroke. Sleep assessment and management should enter in the routinary evaluation of stroke patients, of both acute and chronic phase. Future research should focus on the efficacy of specific sleep intervention as a therapeutic option for stroke patients.

Is There a Place for Medicinal Cannabis in Treating Patients with Sleep Disorders? What We Know so Far

The legalization of cannabis for medicinal, and in some countries, recreational, purposes in addition to growth in the cannabis industry has meant that cannabis use and interest in the area has increased rapidly over the past 20 years. Treatment of poor sleep and sleep disorders are two of the most common reasons for the current use of medicinal cannabis. However, evidence for the role of medical cannabis in the treatment of sleep disorders has not been clearly established, thus making it challenging for clinicians to make evidence-based decisions regarding efficacy and safety. This narrative review summarizes the highest quality clinical evidence currently available in relation to the use of medicinal cannabis for the treatment of sleep disorders including insomnia, obstructive sleep apnea, restless legs syndrome, rapid eye movement sleep behavior disorder, nightmare disorder and narcolepsy. A summary of the effect of cannabis on sleep quality and architecture is also presented. Currently, there is insufficient evidence to support the routine use of medicinal cannabis as an effective and safe treatment option for any sleep disorder. Nevertheless, emerging evidence is promising and warrants further investigation using standardized cannabinoid products and validated quantitative measurement techniques.

Sleep apnoea and ischaemic stroke: current knowledge and future directions

Sleep apnoea, one of the most common chronic diseases, is a risk factor for ischaemic stroke, stroke recurrence, and poor functional recovery after stroke. More than half of stroke survivors present with sleep apnoea during the acute phase after stroke, with obstructive sleep apnoea being the most common subtype. Following a stroke, sleep apnoea frequency and severity might decrease over time, but moderate to severe sleep apnoea is nevertheless present in up to a third of patients in the chronic phase after an ischaemic stroke. Over the past few decades evidence suggests that treatment for sleep apnoea is feasible during the acute phase of stroke and might favourably affect recovery and long-term outcomes. Nevertheless, sleep apnoea still remains underdiagnosed and untreated in many cases, due to challenges in the detection and prediction of post-stroke sleep apnoea, uncertainty as to the optimal timing for its diagnosis, and a scarcity of clear treatment guidelines (ie, uncertainty on when to treat and the optimal treatment strategy). Moreover, the pathophysiology of sleep apnoea associated with stroke, the proportion of stroke survivors with obstructive and central sleep apnoea, and the temporal evolution of sleep apnoea subtypes following stroke remain to be clarified. To address these shortcomings, the management of sleep apnoea associated with stroke should be integrated into a multidisciplinary diagnostic, treatment, and follow-up strategy.

Sleep-wake disturbances in supra-and infratentorial stroke: an analysis of post-acute sleep architecture and apnea

BACKGROUND AND PURPOSE

Sleep-wake disturbances (SWD) are common following stroke, and often extend into the post-acute to chronic periods of recovery. Of particular interest to recovery is a reduction in rapid eye movement (REM) sleep, as we know REM sleep to be important for learning and memory. While there is a breadth of evidence linking SWD and stroke, much less work has been done to identify and determine if differences in sleep architecture and apnea severity are dependent on stroke infarct topographies.

METHODS

A retrospective chart review was conducted of 48 ischemic stroke patients having underwent a full, overnight polysomnography (PSG). All patients were over 30 days post-injury (post-acute) at the time of the PSG. Patients were divided into supra- and infratentorial infarct topography groups based on available medical and imaging records. In addition to sleep study record review, cognitive and outcome measures were examined.

RESULTS

Results showed that patients with infratentorial stroke had poorer sleep efficiency, decreased REM sleep, and higher apnea hypopnea index (AHI) than those with supratentorial injuries. Longer continuous REM periods were correlated with higher verbal learning/memory scores, higher levels of positive affect, and lower levels of emotional/behavioral dyscontrol. Neither age nor AHI were significantly correlated with the amount or duration of REM. Slow-wave sleep was significantly reduced across both injury topographies.

CONCLUSIONS

Infratentorial ischemic stroke patients display significant disruptions in sleep architecture and may require close monitoring for SWDs in the post-acute period to maximize outcome potential. REM sleep is particularly affected when compared to supratentorial ischemic stroke.

Measuring Sleep, Wakefulness, and Circadian Functions in Neurologic Disorders

Neurologic disorders impact the ability of the brain to regulate sleep, wake, and circadian functions, including state generation, components of state (such as rapid eye movement sleep muscle atonia, state transitions) and electroencephalographic microarchitecture. At its most extreme, extensive brain damage may even prevent differentiation of sleep stages from wakefulness (eg, status dissociatus). Given that comorbid sleep-wake-circadian disorders are common and can adversely impact the occurrence, evolution, and management of underlying neurologic conditions, new technologies for long-term monitoring of neurologic patients may potentially usher in new diagnostic strategies and optimization of clinical management.

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.

Association Between Sleep Duration and Functional Disability in Inpatient Stroke Rehabilitation: A Pilot Observational Study

Objective

To describe the change in sleep duration during inpatient rehabilitation and to determine if sleep quality and sleep duration is associated with functional disability for individuals after stroke. It was hypothesized that participants who experienced optimal sleep during inpatient rehabilitation would have greater functional ability at discharge.

Design

Longitudinal observation study.

Setting

Inpatient rehabilitation unit at a large, urban hospital.

Participants

Thirty-seven individuals with acute stroke (N=37; mean age, 62.5±11.8y, male=20, female=17) were recruited from September 2018 to September 2019. Participants were invited to participate in the study by clinical personnel associated with their usual care as they were admitted to inpatient rehabilitation.

Interventions

Not applicable.

Main Outcome Measures

Participants were asked to wear an actigraph for the duration of their rehabilitation program to assess sleep. The first 3 nights of actigraphy data were averaged to obtain total sleep time (TST) and sleep efficiency (SE) at admission, and the last 3 nights were averaged for TST and SE at discharge. Functional disability (primary outcome was FIM) at admission and discharge was gathered from the participants’ medical records. One-way analysis of variance and chi-square analyses assessed for group differences, and regression modeling was used to determine if sleep was associated with functional ability at discharge.

Results

Sixteen participants (43%) were categorized as “good sleepers” and 21 (57%) were “poor sleepers” based on their TST at admission. Of the poor sleepers, 14 participants (66%) remained short duration sleepers (<7h at admission and discharge). Sleep outcomes did not significantly predict FIM score at discharge.

Conclusions

Most participants had less than optimal sleep duration during inpatient rehabilitation. Efforts may be warranted to optimize sleep during inpatient rehabilitation.

Melatonin supplementation in the subacute phase after ischemia alleviates postischemic sleep disturbances in rats

BACKGROUND

Sleep disorders are highly prevalent among stroke survivors and impede stroke recovery. It is well established that melatonin has neuroprotective effects in animal models of ischemic stroke. However, as a modulator of endogenous physiological circadian rhythms, the effects of melatonin on poststroke sleep disorders remain unclear. In the present study, we investigated how melatonin delivered intraperitoneally once daily in the subacute phase after stroke onset, influencing neuronal survival, motor recovery, and sleep-wake profiles in rats.

METHODS

Transient ischemic stroke in male Sprague-Dawley rats was induced with 30 min occlusion of the middle cerebral artery. Melatonin or vehicle was delivered intraperitoneally once daily in the subacute phase, from 2 to 7 days after stroke. Electroencephalogram and electromyogram recordings were obtained simultaneously.

RESULTS

Compared to the effects observed in the vehicle-treated ischemic group, after 6 daily consecutive treatment of melatonin at 10 mg/kg starting at ischemic/reperfusion day 2, the infarct volume was significantly decreased (from 39.6 to 26.2%), and the degeneration of axons in the ipsilateral striatum and the contralateral corpus callosum were significantly alleviated. Sensorimotor performances were obviously improved as evidenced by significant increases in the latency to falling off the wire and in the use of the impaired forelimb. In addition to those predictable results of reducing brain tissue damage and mitigating behavioral deficits, repeated melatonin treatment during the subacute phase of stroke also alleviated sleep fragmentation through reducing sleep-wake stage transitions and stage bouts, together with increasing stage durations. Furthermore, daily administration of melatonin at 9 a.m. significantly increased the nonrapid eye movement sleep delta power during both the light and dark periods and decreased the degree of reduction of the circadian index.

CONCLUSIONS

Melatonin promptly reversed ischemia-induced sleep disturbances. The neuroprotective effects of melatonin on ischemic injury may be partially associated with its role in sleep modulation.

Thalamic Influence on Slow Wave Slope Renormalization During Sleep

Objective

Slow waves are thought to mediate an overall reduction in synaptic strength during sleep. The specific contribution of the thalamus to this so‐called synaptic renormalization is unknown. Thalamic stroke is associated with daytime sleepiness, along with changes to sleep electroencephalography and cognition, making it a unique “experiment of nature” to assess the relationship between sleep rhythms, synaptic renormalization, and daytime functions.

Methods

Sleep was studied by polysomnography and high‐density electroencephalography over 17 nights in patients with thalamic (n = 12) and 15 nights in patients with extrathalamic (n = 11) stroke. Sleep electroencephalographic overnight slow wave slope changes and their relationship with subjective daytime sleepiness, cognition, and other functional tests were assessed.

Results

Thalamic and extrathalamic patients did not differ in terms of age, sleep duration, or apnea–hypopnea index. Conversely, overnight slope changes were reduced in a large cluster of electrodes in thalamic compared to extrathalamic stroke patients. This reduction was related to increased daytime sleepiness. No significant differences were found in other functional tests between the 2 groups.

Interpretation

In patients with thalamic stroke, a reduction in overnight slow wave slope change and increased daytime sleepiness was found. Sleep‐ and wake‐centered mechanisms for this relationship are discussed. Overall, this study suggests a central role of the thalamus in synaptic renormalization. ANN NEUROL 2021;90:821–833

Physical Therapy Exercises for Sleep Disorders in a Rehabilitation Setting for Neurological Patients: A Systematic Review and Meta-Analysis

Background: Sleep occupies one-third of human life and is essential for health and for emotional, physical, and cognitive well-being. Poor or insufficient sleep is associated with a wide range of dysfunctions that involve different body systems, such as the endocrine, metabolic, and immune systems, thus compromising the higher cortical functions, cognitive performance, mood, and post-physical activity recovery. The present systematic review and meta-analysis aimed to explore the effectiveness of physical therapy exercises on sleep disorders in patients with neurological disorders. Our systematic review identified 10 articles that investigated the effects of physical therapy on sleep disorders in patients with neurological disorders, 6 of which were included in the meta-analysis. Results suggest that physical therapy exercises are a safe and useful strategy for managing sleep disorders in neurorehabilitation.

Obstructive Sleep Apnea: Cognitive Outcomes

There is a strong association between obstructive sleep apnea (OSA) and cognitive dysfunction. Executive function, attention, verbal/visual long-term memory, visuospatial/constructional ability, and information processing are more likely to be affected, whereas language, psychomotor function, and short-term memory are less likely to be affected. Increased accumulation of Aß₂-amyloid in the brain, episodic hypoxemia, oxidative stress, vascular inflammation, and systemic comorbidities may contribute to the pathogenesis. Patients with OSA should have cognitive screening or formal testing, and patients with cognitive decline should have testing for OSA. Treatment with continuous positive airway pressure may improve cognitive symptoms in the patient with OSA.

Efficacy and safety of electroacupuncture combined with Suanzaoren decoction for insomnia following stroke: study protocol for a randomized controlled trial

BACKGROUND

Insomnia is a common but frequently overlooked sleep disorder after stroke, and there are limited effective therapies for insomnia following stroke. Traditional Chinese medicine (TCM), including acupuncture and the Chinese herbal medication (CHM) Suanzaoren decoction (SZRD), has been reported as an alternative option for insomnia relief after stroke in China for thousands of years. Here, this study aims to investigate the efficacy and safety of electroacupuncture (EA) in combination with SZRD in the treatment of insomnia following stroke.

METHODS

A total of 240 patients with post-stroke insomnia will be included and randomized into four groups: the EA group, SZRD group, EA & SZRD group, and sham group. The same acupoints (GV20, GV24, HT7, and SP6) will be used in the EA group, EA & SZRD group, and sham group, and these patients will receive the EA treatment or sham manipulation every other day for 4 consecutive weeks. SZRD treatments will be given to participants in the SZRD group and EA & SZRD group twice a day for 4 consecutive weeks. The primary outcome measures include Pittsburgh Sleep Quality Index scores and polysomnography. Secondary outcome measures include the Insomnia Severity Index, the National Institutes of Health Stroke Scale, the Hospital Anxiety and Depression Scale, brain magnetic resonance imaging, functional magnetic resonance imaging, and nocturnal melatonin concentrations. The primary and secondary outcomes will be assessed at baseline (before treatment), during the 2nd and 4th weeks of the intervention, and at the 8th and 12th weeks of follow-up. Safety assessments will be evaluated at baseline and during the 4th week of the intervention.

DISCUSSION

This study will contribute to assessing whether the combination of these two therapies is more beneficial for post-stroke insomnia than their independent use, and the results of this clinical trial will improve our understanding of the possible mechanisms underlying the effects of combination therapies.

TRIAL REGISTRATION

Chinese Clinical Trials Register ChiCTR2000031413 . Registered on March 30, 2020.

Self-Reported and Objective Sleep Measures in Stroke Survivors With Incomplete Motor Recovery at the Chronic Stage

Background. Stroke survivors commonly complain of difficulty sleeping. Poor sleep is associated with reduced quality of life and more understanding of long-term consequences of stroke on sleep is needed. Objective. The primary aims were to (1) compare sleep measures between chronic stroke survivors and healthy controls and (2) test for a relationship between motor impairment, time since stroke and sleep. Secondary aims were to explore mood and inactivity as potential correlates of sleep and test the correlation between self-reported and objective sleep measures. Methods. Cross-sectional sleep measures were obtained for 69 chronic stroke survivors (mean 65 months post-stroke, 63 years old, 24 female) and 63 healthy controls (mean 61 years old, 27 female). Self-reported sleep was assessed with the sleep condition indicator (SCI) and sleep diary ratings, objective sleep with 7-nights actigraphy and mood with the Hospital Anxiety and Depression Scale. Upper extremity motor impairment was assessed with the Fugl-Meyer assessment. Results. Stroke survivors had significantly poorer SCI score (P < .001) and higher wake after sleep onset (P = .005) than controls. Neither motor impairment, nor time since stroke, explained significant variance in sleep measures for the stroke group. For all participants together, greater depression was associated with poorer SCI score (R²_adj = .197, P < .001) and higher age with more fragmented sleep (R²_adj = .108, P < .001). There were weak correlations between nightly sleep ratings and actigraphy sleep measures (r_s = .15-.24). Conclusions. Sleep disturbance is present long-term after stroke. Depressive symptoms may present a modifiable factor which should be investigated alongside techniques to improve sleep in this population.

Sleep in disorders of consciousness: diagnostic, prognostic, and therapeutic considerations

PURPOSE OF REVIEW

Sleep is important in the evaluation of patients with disorders of consciousness (DOC). However, it remains unclear whether reconstitution of sleep could enable consciousness or vice versa. Here we synthesize recent evidence on natural recovery of sleep in DOC, and sleep-promoting therapeutic interventions for recovery of consciousness.

RECENT FINDINGS

In subacute DOC, physiological sleep--wake cycles and complex sleep patterns are related to better outcomes. Moreover, structured rapid-eye-movement (REM), non-REM (NREM) stages, and presence of sleep spindles correlate with full or partial recovery. In chronic DOC, sleep organization may reflect both integrity of consciousness-supporting brain networks and engagement of those networks during wakefulness. Therapeutic strategies have integrated improvement of sleep and sleep--wake cycles in DOC patients; use of bright light stimulation or drugs enhancing sleep and/or vigilance, treatment of sleep apneas, and neuromodulatory stimulations are promising tools to promote healthy sleep architecture and wakeful recovery.

SUMMARY

Sleep features and sleep--wake cycles are important prognostic markers in subacute DOC and can provide insight into covert recovery in chronic DOC. Although large-scale studies are needed, preliminary studies in limited patients suggest that therapeutic options restoring sleep and/or sleep--wake cycles may improve cognitive function and outcomes in DOC.