Showing papers on "Polysomnography published in 2022"

Safety and efficacy of daridorexant in patients with insomnia disorder: results from two multicentre, randomised, double-blind, placebo-controlled, phase 3 trials

Abstract: Daytime functioning is impaired in people with insomnia disorder. Currently available dual orexin receptor antagonists have shown efficacy in insomnia disorder, but do not address all aspects of this disease. We aimed to assess safety and efficacy of daridorexant, a novel orexin receptor antagonist, on night-time and daytime symptoms of insomnia.We did two multicentre, randomised, double-blind, placebo-controlled, phase 3 trials at 156 sites in 17 countries. Adults (aged ≥18 years) with insomnia disorder were randomly assigned using interactive response technology (1:1:1) to receive daridorexant 50 mg, 25 mg, or placebo (study 1) or daridorexant 25 mg, 10 mg, or placebo (study 2) every evening for 3 months. Participants, investigators, and site personnel were masked to treatment allocation. The primary endpoints were change from baseline in wake time after sleep onset (WASO) and latency to persistent sleep (LPS), measured by polysomnography, at months 1 and 3. The secondary endpoints were change from baseline in self-reported total sleep time and the sleepiness domain score of the Insomnia Daytime Symptoms and Impacts Questionnaire (IDSIQ) at months 1 and 3. Study-wise type I error rate (5%) was controlled for all pairwise comparisons. Efficacy was analysed in all randomly assigned participants, and safety in all participants who received at least one dose of treatment. The studies are registered at ClinicalTrials.gov, NCT03545191 (study 1) and NCT03575104 (study 2).Between June 4, 2018 and Feb 25, 2020, 930 participants were randomly assigned to receive daridorexant 50 mg (n=310), daridorexant 25 mg (n=310), or placebo (n=310) in study 1. Between May 29, 2018, and May 14, 2020, 924 participants were randomly assigned to receive daridorexant 25 mg (n=309), daridorexant 10 mg (n=307), or placebo (n=308) in study 2. In study 1, WASO and LPS were significantly reduced among participants in the daridorexant 50 mg group compared with participants in the placebo group at month 1 (least squares mean [LSM] difference -22·8 min [95% CI -28·0 to -17·6], p<0·0001 for WASO; -11·4 min [-16·0 to -6·7], p<0·0001 for LPS) and month 3 (-18·3 min [-23·9 to -12·7], p<0·0001 for WASO; -11·7 min [-16·3 to -7·0], p<0·0001 for LPS). WASO and LPS were significantly reduced among participants in the daridorexant 25 mg group compared with the placebo group at month 1 (LSM difference -12·2 min [-17·4 to -7·0], p<0·0001 for WASO; -8·3 min [-13·0 to -3·6], p=0·0005 for LPS) and month 3 (-11·9 min [-17·5 to -6·2], p<0·0001 for WASO; -7·6 min [-12·3 to -2·9], p=0·0015 for LPS). Compared with placebo, participants in the daridorexant 50 mg group had significantly improved self-reported total sleep time at month 1 (LSM difference 22·1 min [14·4 to 29·7], p<0·0001) and month 3 (19·8 min [10·6 to 28·9], p<0·0001), and IDSIQ sleepiness domain scores at month 1 (-1·8 [-2·5 to -1·0], p<0·0001) and month 3 (-1·9 [-2·9 to -0·9], p=0·0002). Compared with the placebo group, participants in the daridorexant 25 mg group had significantly improved self-reported total sleep time at month 1 (LSM difference 12·6 min [5·0 to 20·3], p=0·0013) and month 3 (9·9 min [0·8 to 19·1], p=0·033), but not IDSIQ sleepiness domain scores (-0·8 [-1·5 to 0·01], p=0·055 at month 1; -1·0 [-2·0 to 0·01], p=0·053 at month 3). In study 2, WASO was significantly reduced among participants in the daridorexant 25 mg group compared with participants in the placebo group at month 1 (LSM difference -11·6 min [-17·6 to -5·6], p=0·0001) and month 3 (-10·3 min [-17·0 to -3·5], p=0·0028), whereas no significant differences in LPS were observed at month 1 (-6·5 min [-12·3 to -0·6], p=0·030) or month 3 (-9·0 [-15·3 to -2·7], p=0·0053). Compared with the placebo group, participants in the daridorexant 25 mg group had significant improvement in self-reported total sleep time at month 1 (LSM difference 16·1 min [8·2 to 24·0], p<0·0001) and month 3 (19·1 [10·1 to 28·0], p<0·0001), but not in IDSIQ sleepiness domain scores (-0·8 [-1·6 to 0·1], p=0·073 at month 1; -1·3 [-2·2 to -0·3], p=0·012 at month 3). Compared with the placebo group, no significant differences were observed among participants in the daridorexant 10 mg group for WASO (LSM difference -2·7 min [-8·7 to 3·2], p=0·37 at month 1; -2·0 [-8·7 to 4·8], p=0·57 at month 3), LPS (-2·6 min [-8·4 to 3·2], p=0·38 at month 1; -3·2 min [-9·5 to 3·1], p=0·32 at month 3), self-reported total sleep time (13·4 min [5·5 to 21·2], p=0·0009 at month 1; 13·6 min [4·7 to 22·5], p=0·0028 at month 3), nor IDSIQ sleepiness domain scores (-0·4 [-1·3 to 0·4], p=0·30 at month 1; -0·7 [-1·7 to 0·2], p=0·14 at month 3). Overall incidence of adverse events was comparable between treatment groups (116 [38%] of 308 participants in the daridorexant 50 mg group, 117 [38%] of 310 in the daridorexant 25 mg group, and 105 [34%] of 309 in the placebo group in study 1; 121 [39%] of 308 participants in the daridorexant 25 mg group, 117 [38%] of 306 in the daridorexant 10 mg group, and 100 [33%] of 306 in the placebo group). Nasopharyngitis and headache were the most common adverse events in all groups. One death (cardiac arrest) occurred in the daridorexant 25 mg group in study 1, which was not deemed to be treatment-related.Daridorexant 25 mg and 50 mg improved sleep outcomes, and daridorexant 50 mg also improved daytime functioning, in people with insomnia disorder, with a favourable safety profile.Idorsia Pharmaceuticals.

Quantitative Evaluation of EEG-Biomarkers for Prediction of Sleep Stages

Abstract: Electroencephalography (EEG) is immediate and sensitive to neurological changes resulting from sleep stages and is considered a computing tool for understanding the association between neurological outcomes and sleep stages. EEG is expected to be an efficient approach for sleep stage prediction outside a highly equipped clinical setting compared with multimodal physiological signal-based polysomnography. This study aims to quantify the neurological EEG-biomarkers and predict five-class sleep stages using sleep EEG data. We investigated the three-channel EEG sleep recordings of 154 individuals (mean age of 53.8 ± 15.4 years) from the Haaglanden Medisch Centrum (HMC, The Hague, The Netherlands) open-access public dataset of PhysioNet. The power of fast-wave alpha, beta, and gamma rhythms decreases; and the power of slow-wave delta and theta oscillations gradually increases as sleep becomes deeper. Delta wave power ratios (DAR, DTR, and DTABR) may be considered biomarkers for their characteristics of attenuation in NREM sleep and subsequent increase in REM sleep. The overall accuracy of the C5.0, Neural Network, and CHAID machine-learning models are 91%, 89%, and 84%, respectively, for multi-class classification of the sleep stages. The EEG-based sleep stage prediction approach is expected to be utilized in a wearable sleep monitoring system.

Multinight Prevalence, Variability, and Diagnostic Misclassification of Obstructive Sleep Apnea

Abstract: Rationale: Recent studies suggest that obstructive sleep apnea (OSA) severity can vary markedly from night to night, which may have important implications for diagnosis and management. Objectives: This study aimed to assess OSA prevalence from multinight in-home recordings and the impact of night-to-night variability in OSA severity on diagnostic classification in a large, global, nonrandomly selected community sample from a consumer database of people that purchased a novel, validated, under-mattress sleep analyzer. Methods: A total of 67,278 individuals aged between 18 and 90 years underwent in-home nightly monitoring over an average of approximately 170 nights per participant between July 2020 and March 2021. OSA was defined as a nightly mean apnea-hypopnea index (AHI) of more than 15 events/h. Outcomes were multinight global prevalence and likelihood of OSA misclassification from a single night's AHI value. Measurements and Main Results: More than 11.6 million nights of data were collected and analyzed. OSA global prevalence was 22.6% (95% confidence interval, 20.9-24.3%). The likelihood of misdiagnosis in people with OSA based on a single night ranged between approximately 20% and 50%. Misdiagnosis error rates decreased with increased monitoring nights (e.g., 1-night F1-score = 0.77 vs. 0.94 for 14 nights) and remained stable after 14 nights of monitoring. Conclusions: Multinight in-home monitoring using novel, noninvasive under-mattress sensor technology indicates a global prevalence of moderate to severe OSA of approximately 20%, and that approximately 20% of people diagnosed with a single-night study may be misclassified. These findings highlight the need to consider night-to-night variation in OSA diagnosis and management.

A Validation of Six Wearable Devices for Estimating Sleep, Heart Rate and Heart Rate Variability in Healthy Adults

Abstract: The primary aim of this study was to examine the validity of six commonly used wearable devices, i.e., Apple Watch S6, Garmin Forerunner 245 Music, Polar Vantage V, Oura Ring Generation 2, WHOOP 3.0 and Somfit, for assessing sleep. The secondary aim was to examine the validity of the six devices for assessing heart rate and heart rate variability during, or just prior to, night-time sleep. Fifty-three adults (26 F, 27 M, aged 25.4 ± 5.9 years) spent a single night in a sleep laboratory with 9 h in bed (23:00–08:00 h). Participants were fitted with all six wearable devices—and with polysomnography and electrocardiography for gold-standard assessment of sleep and heart rate, respectively. Compared with polysomnography, agreement (and Cohen’s kappa) for two-state categorisation of sleep periods (as sleep or wake) was 88% (κ = 0.30) for Apple Watch; 89% (κ = 0.35) for Garmin; 87% (κ = 0.44) for Polar; 89% (κ = 0.51) for Oura; 86% (κ = 0.44) for WHOOP and 87% (κ = 0.48) for Somfit. Compared with polysomnography, agreement (and Cohen’s kappa) for multi-state categorisation of sleep periods (as a specific sleep stage or wake) was 53% (κ = 0.20) for Apple Watch; 50% (κ = 0.25) for Garmin; 51% (κ = 0.28) for Polar; 61% (κ = 0.43) for Oura; 60% (κ = 0.44) for WHOOP and 65% (κ = 0.52) for Somfit. Analyses regarding the two-state categorisation of sleep indicate that all six devices are valid for the field-based assessment of the timing and duration of sleep. However, analyses regarding the multi-state categorisation of sleep indicate that all six devices require improvement for the assessment of specific sleep stages. As the use of wearable devices that are valid for the assessment of sleep increases in the general community, so too does the potential to answer research questions that were previously impractical or impossible to address—in some way, we could consider that the whole world is becoming a sleep laboratory.

OSACN-Net: Automated Classification of Sleep Apnea Using Deep Learning Model and Smoothed Gabor Spectrograms of ECG Signal

Abstract: Obstructive sleep apnea (OSA) is a severe sleep-associated respiratory disorder, caused due to periodic disruption of breath during sleep. It may cause a number of serious cardiovascular complications, including stroke. Generally, OSA is detected by polysomnography (PSG), a costly procedure, and may cause discomfort to the patient. Nowadays, electrocardiogram (ECG) signal-based detection techniques have been explored as an alternative to PSG for OSA detection. Usual linear and nonlinear machine learning techniques are mainly focused on handcrafted feature extraction and classification that are time-consuming and may not be suitable for huge data. Therefore, in this work, a deep learning model (DLM) using smoothed Gabor spectrogram (SGS) of ECG signals is proposed for automated OSA detection to obtain high performance. The proposed framework fed Gabor spectrogram and SGS of ECG signals as input to the pretrained Squeeze-Net, Res-Net50, and developed DLM called obstructive sleep apnea convolutional neural network (OSACN-Net). The proposed OSACN-Net achieved an average classification accuracy of 94.81% with SGS using a tenfold cross-validation strategy. Compared to Squeeze-Net and Res-Net50, developed OSACN-Net is more accurate and lightweight as it requires few learnable parameters, which makes it computationally fast and efficient. The comparison results showed that the proposed framework outperformed all existing state-of-the-art methodologies.

Sleep in Alzheimer’s disease: a systematic review and meta-analysis of polysomnographic findings

Abstract: Polysomnography (PSG) studies of sleep changes in Alzheimer's disease (AD) have reported but not fully established the relationship between sleep disturbances and AD. To better detail this relationship, we conducted a systematic review and meta-analysis of reported PSG differences between AD patients and healthy controls. An electronic literature search was conducted in EMBASE, MEDLINE, All EBM databases, CINAHL, and PsycINFO inception to Mar 2021. Twenty-eight studies were identified for systematic review, 24 of which were used for meta-analysis. Meta-analyses revealed significant reductions in total sleep time, sleep efficiency, and percentage of slow-wave sleep (SWS) and rapid eye movement (REM) sleep, and increases in sleep latency, wake time after sleep onset, number of awakenings, and REM latency in AD compared to controls. Importantly, both decreased SWS and REM were significantly associated with the severity of cognitive impairment in AD patients. Alterations in electroencephalogram (EEG) frequency components and sleep spindles were also observed in AD, although the supporting evidence for these changes was limited. Sleep in AD is compromised with increased measures of wake and decreased TST, SWS, and REM sleep relative to controls. AD-related reductions in SWS and REM sleep correlate with the degree of cognitive impairment. Alterations in sleep EEG frequency components such as sleep spindles may be possible biomarkers with relevance for diagnosing AD although their sensitivity and specificity remain to be clearly delineated. AD-related sleep changes are potential targets for early therapeutic intervention aimed at improving sleep and slowing cognitive decline.

Ventilatory Drive Withdrawal Rather Than Reduced Genioglossus Compensation as a Mechanism of Obstructive Sleep Apnea in REM Sleep

Abstract: Rationale: REM sleep is associated with reduced ventilation and greater obstructive sleep apnea (OSA) severity than non-REM (nREM) sleep for reasons that have not been fully elucidated. Objectives: Here, we use direct physiological measurements to determine whether the pharyngeal compromise in REM sleep OSA is most consistent with 1) withdrawal of neural ventilatory drive or 2) deficits in pharyngeal pathophysiology per se (i.e., increased collapsibility and decreased muscle responsiveness). Methods: Sixty-three participants with OSA completed sleep studies with gold standard measurements of ventilatory “drive” (calibrated intraesophageal diaphragm EMG), ventilation (oronasal “ventilation”), and genioglossus EMG activity. Drive withdrawal was assessed by examining these measurements at nadir drive (first decile of drive within a stage). Pharyngeal physiology was assessed by examining collapsibility (lowered ventilation at eupneic drive) and responsiveness (ventilation–drive slope). Mixed-model analysis compared REM sleep with nREM sleep; sensitivity analysis examined phasic REM sleep. Measurements and Main Results: REM sleep (⩾10 min) was obtained in 25 patients. Compared with drive in nREM sleep, drive in REM sleep dipped to markedly lower nadir values (first decile, estimate [95% confidence interval], −21.8% [−31.2% to −12.4%] of eupnea; P < 0.0001), with an accompanying reduction in ventilation (−25.8% [−31.8% to −19.8%] of eupnea; P < 0.0001). However, there was no effect of REM sleep on collapsibility (ventilation at eupneic drive), baseline genioglossus EMG activity, or responsiveness. REM sleep was associated with increased OSA severity (+10.1 [1.8 to 19.8] events/h), but this association was not present after adjusting for nadir drive (+4.3 [−4.2 to 14.6] events/h). Drive withdrawal was exacerbated in phasic REM sleep. Conclusions: In patients with OSA, the pharyngeal compromise characteristic of REM sleep appears to be predominantly explained by ventilatory drive withdrawal rather than by preferential decrements in muscle activity or responsiveness. Preventing drive withdrawal may be the leading target for REM sleep OSA.

Common Sleep Disorders in Children.

Abstract: Childhood sleep disorders can disrupt family dynamics and cause cognitive and behavior problems. Early recognition and management can prevent these complications. Behavior subtypes of childhood insomnias affect 10% to 30% of children and result from inconsistent parental limit-setting and improper sleep-onset association. Behavior insomnias are treated using extinction techniques and parent education. Hypnotic medications are not recommended. Obstructive sleep apnea affects 1% to 5% of children. Polysomnography is required to diagnose obstructive sleep apnea; history and physical examination alone are not adequate. Adenotonsillectomy is the first-line treatment for obstructive sleep apnea. Nasal continuous positive airway pressure is the second-line treatment for children who do not respond to surgery or if adenotonsillectomy is contraindicated. Restless legs syndrome can be difficult to recognize and has an association with attention-deficit/hyperactivity disorder. Management of restless legs syndrome includes treatment of iron deficiency, if identified, and removal of triggering factors. Parasomnias affect up to 50% of children and usually resolve spontaneously by adolescence. Management of parasomnias involves parental education, reassurance, safety precautions, and treating comorbid conditions. Delayed sleep phase syndrome is found during adolescence, manifesting as a night owl preference. Treatment of delayed sleep phase syndrome includes sleep hygiene, nighttime melatonin, and morning bright light exposure. Sleep deprivation is of increasing concern, affecting 68% of people in high school.

Bruxism definition: Past, present, and future – What should a prosthodontist know?

Abstract: The definition of bruxism has evolved, and the dental profession needs to align with the terminologies adopted in the current literature of sleep and orofacial pain medicine.The purpose of this review was to discuss the recent evolution of bruxism concepts and the implications for changing the definition that is currently used by the prosthodontic community.A historical perspective on the evolution of the definition of bruxism, as well as a systematic literature review on the validity of polysomnography (PSG)-based criteria for sleep bruxism diagnosis to detect the presence of clinical consequences, is presented. Selected articles were read in a structured Population, Intervention, Comparison, Outcome (PICO) format to answer the question "If a target population with conditions such as tooth wear, dental implant complications, and temporomandibular disorders (P) is diagnosed with sleep bruxism by means of PSG (I) and compared with a population of nonbruxers (C), is the occurrence of the condition under investigation (that is, the possible pathologic consequences of sleep bruxism) be different between the 2 groups (O)?"Eight studies were eligible for the review, 6 of which assessed the relationship between PSG-diagnosed sleep bruxism and temporomandibular disorder pain, while the other 2 articles evaluated the predictive value of tooth wear for ongoing PSG-diagnosed sleep bruxism and the potential role of sleep bruxism in a population of patients with failed dental implants. Findings were contradictory and not supportive of a clear-cut relationship between sleep bruxism assessed based on available PSG criteria and any clinical consequence. The literature providing definitions of bruxism as a motor behavior and not pathology has been discussed.The bruxism construct has shifted from pathology to motor activity with possibly even physiological or protective relevance. An expert panel including professionals from different medical fields published 2 consecutive articles focusing on the definition of bruxism, as well as an overview article presenting the ongoing work to prepare a Standardized Tool for the Assessment of Bruxism (STAB) to reflect the current bruxism paradigm shift from pathology to behavior (that is, muscle activity). As such, dental practitioners working in the field of restorative dentistry and prosthodontics are encouraged to appraise this evolution.

Cardiovascular Benefit of Continuous Positive Airway Pressure in Adults with Coronary Artery Disease and Obstructive Sleep Apnea without Excessive Sleepiness

Abstract: Rationale: Randomized controlled trials of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) have not demonstrated protection against adverse cardiovascular outcomes. Recently, observational studies revealed that OSA-related cardiovascular risk is concentrated in patients with an elevated pulse rate response to respiratory events (ΔHR). Objectives: Here, in this post hoc analysis of a prospective clinical trial, we test the hypothesis that a greater pretreatment ΔHR is associated with greater CPAP-related protection against adverse cardiovascular outcomes. Methods: ΔHR was measured from baseline polysomnography of the RICCADSA (Randomized Intervention with CPAP in CAD and OSA) randomized controlled trial (patients with coronary artery disease [CAD] and OSA [apnea-hypopnea index ⩾ 15 events/h] with Epworth Sleepiness Scale score < 10; nCPAP:ncontrol = 113:113; male, 85%; age, 66 ± 8 [mean ± SD] yr). The primary outcome was a composite of repeat revascularization, myocardial infarction, stroke, and cardiovascular mortality. Multivariable Cox regression assessed whether the effect of CPAP was moderated by ΔHR (treatment-by-ΔHR interaction). Measurements and Main Results: The CPAP-related reduction in risk increased progressively with increasing pretreatment ΔHR (interaction hazard ratio [95% confidence interval], 0.49 [0.27 to 0.90] per SD increase in ΔHR; P < 0.05). This means that in patients with a ΔHR of 1 SD above the mean (i.e., 10 beats/min), CPAP was estimated to reduce cardiovascular risk by 59% (6% to 82%) (P < 0.05), but no significant risk reduction was estimated in patients with a mean ΔHR (6 beats/min; CPAP risk reduction, 16% [-53% to 54%]; P = 0.6). Conclusions: The protective effect of CPAP in patients with CAD and OSA without excessive sleepiness was modified by the ΔHR. Specifically, patients with higher ΔHR exhibit greater cardiovascular benefit from CPAP therapy.

Improvements in Cognitive Function and Quantitative Sleep EEG in OSA after Six Months of CPAP Treatment.

Abstract: STUDY OBJECTIVES Untreated obstructive sleep apnea (OSA) is associated with cognitive deficits and altered brain electrophysiology. We evaluated the effect of continuous positive airway pressure (CPAP) treatment on quantitative sleep electroencephalogram (EEG) measures and cognitive function. METHODS We studied 162 OSA patients (age 50±13, AHI 35.0±26.8) before and after 6 months of CPAP. Cognitive tests assessed working memory, sustained attention, visuospatial scanning and executive function. All participants underwent overnight polysomnography at baseline and after CPAP. Power spectral analysis was performed on EEG data (C3-M2) in a sub-set of 90 participants. Relative delta EEG power and sigma power in NREM and EEG slowing in REM were calculated. Spindle densities (events p/min) in N2 were also derived using automated spindle event detection. All outcomes were analysed as change from baseline. RESULTS Cognitive function across all cognitive domains improved after six months of CPAP. In our sub-set, increased relative delta power (p<0.0001) and reduced sigma power (p=0.001) during NREM were observed after the 6-month treatment period. Overall, fast and slow sleep spindle densities during N2 were increased after treatment. CONCLUSIONS Cognitive performance was improved and sleep EEG features were enhanced when assessing the effects of CPAP. These findings suggest the reversibility of cognitive deficits and altered brain electrophysiology observed in untreated OSA following six months of treatment.

Differences in Symptoms and Severity of Obstructive Sleep Apnea between Black and White Patients

Abstract: Rationale: Prior work suggests that Black patients have more severe obstructive sleep apnea (OSA) upon clinical presentation. However, the extent to which this may reflect differences in symptoms or other standard measures of OSA risk is unclear. Objectives: We assessed for racial disparities in OSA characteristics at time of initial clinical diagnosis. Methods: Data from 890 newly diagnosed patients with OSA at an urban academic sleep center were included in this analysis. All patients completed a standardized questionnaire on demographics and sleep-related symptoms and underwent laboratory polysomnography. Symptom severity at the time of evaluation was compared across race and sex. Results: Black men were underrepresented in the sleep lab, making up only 15.8% of the cohort and 31.3% of Black participants (P < 0.001). Despite this, Black men had the most severe OSA with a mean apnea hypopnea index of 52.4 ± 39.4 events/hour, compared with 39.0 ± 28.9 in White men, 33.4 ± 32.3 in Black women, and 26.2 ± 23.8 in White women (P < 0.001 for test of homogeneity). Black men also had the greatest burden of OSA symptoms with the highest mean Epworth Sleepiness Scale score (12.2 ± 5.9 versus 9.4 ± 5.2 in White men, 11.2 ± 5.9, in Black women, and 9.8 ± 5.6 in White women; P < 0.001). Compared with White men, Black men were 1.61 (95% CI [1.04–2.51]) times more likely to have witnessed apneas and 1.56 (95% CI [1.00–2.46]) times more likely to have drowsy driving at the time of OSA diagnosis. Conclusions: At the time of clinical diagnosis, Black men have greater disease severity, suggesting delay in diagnosis. Further, the greater burden of classic OSA symptoms suggests the delayed diagnosis of OSA in Black men is not due to atypical presentation. Further research is needed to identify why screening methods for OSA are not equitably implemented in the care of Black men.

A Comprehensive Review: Computational Models for Obstructive Sleep Apnea Detection in Biomedical Applications

Abstract: Obstructive sleep apnea (OSA) is a sleep disorder characterized by periodic episodes of partial or complete upper airway obstruction caused by narrowing or collapse of the pharyngeal airway despite ongoing breathing efforts during sleep. Fall in the blood oxygen saturation and cortical arousals are prompted by this reduction in the airflow which lasts for at least 10 seconds. Impaired labor performance, debilitated quality of life, excessive daytime sleepiness, high snoring, and tiredness even after a whole night's sleep are the primary symptoms of OSA. In due course, the long-standing contributions of OSA culminate in hypertension, arrhythmia, cerebrovascular disease, and heart failure. The traditional diagnostic approach of OSA is the laboratory-based polysomnography (PSG) overnight sleep study, which is a tedious and labor-intensive process that exaggerates the discomfort to the patient. With the advent of computer-aided diagnosis (CAD), automatic detection of OSA has gained increasing interest among researchers in the area of sleep disorders as it influences both diagnostic and therapeutic decisions. The research literature on sleep apnea published during the last decade has been surveyed, focusing on the varied screening approaches accustomed to identifying OSA events and the developmental knowledge offered by multiple contributors from the software perspective. The current study presents an overview of the pathophysiology of OSA, the detection methods, physiological signals related to OSA, the different preprocessing, feature extraction, feature selection, and classification techniques employed for the detection and classification of OSA. Consequently, the research challenges and research gaps in the diagnosis of OSA are identified, critically analyzed, and presented in the best possible light.

Dyscoordination of Non-Rapid Eye Movement Sleep Oscillations in Autism Spectrum Disorder.

Abstract: STUDY OBJECTIVES Converging evidence from neuroimaging, sleep, and genetic studies suggests that dysregulation of thalamocortical interactions mediated by the thalamic reticular nucleus (TRN) contribute to autism spectrum disorder (ASD). Sleep spindles assay TRN function, and their coordination with cortical slow oscillations (SOs) indexes thalamocortical communication. These oscillations mediate memory consolidation during sleep. In the present study, we comprehensively characterized spindles and their coordination with SOs in relation to memory and age in children with ASD. METHODS Nineteen children and adolescents with ASD, without intellectual disability, and 18 typically developing (TD) peers, aged 9-17, completed a home polysomnography study with testing on a spatial memory task before and after sleep. Spindles, SOs, and their coordination were characterized during stages 2 (N2) and 3 (N3) non-rapid eye movement sleep. RESULTS ASD participants showed disrupted SO-spindle coordination during N2 sleep. Spindles peaked later in SO upstates and their timing was less consistent. They also showed a spindle density (#/min) deficit during N3 sleep. Both groups showed significant sleep-dependent memory consolidation, but its relations with spindle density differed. While TD participants showed the expected positive correlations, ASD participants showed the opposite. CONCLUSIONS The disrupted SO-spindle coordination and spindle deficit provide further evidence of abnormal thalamocortical interactions and TRN dysfunction in ASD. The inverse relations of spindle density with memory suggest a different function for spindles in ASD than TD. We propose that abnormal sleep oscillations reflect genetically mediated disruptions of TRN-dependent thalamocortical circuit development that contribute to the manifestations of ASD and are potentially treatable.

Review on Biomedical Sensors, Technologies and Algorithms for Diagnosis of Sleep Disordered Breathing: Comprehensive Survey

Abstract: This paper provides a comprehensive review of available technologies for measurements of vital physiology related parameters that cause sleep disordered breathing (SDB). SDB is a chronic disease that may lead to several health problems and increase the risk of high blood pressure and even heart attack. Therefore, the diagnosis of SDB at an early stage is very important. The essential primary step before diagnosis is measurement. Vital health parameters related to SBD might be measured through invasive or non-invasive methods. Nowadays, with respect to increase in aging population, improvement in home health management systems is needed more than even a decade ago. Moreover, traditional health parameter measurement techniques such as polysomnography are not comfortable and introduce additional costs to the consumers. Therefore, in modern advanced self-health management devices, electronics and communication science are combined to provide appliances that can be used for SDB diagnosis, by monitoring a patient's physiological parameters with more comfort and accuracy. Additionally, development in machine learning algorithms provides accurate methods of analysing measured signals. This paper provides a comprehensive review of measurement approaches, data transmission, and communication networks, alongside machine learning algorithms for sleep stage classification, to diagnose SDB.

Improvements in cognitive function and quantitative sleep electroencephalogram in obstructive sleep apnea after six months of continuous positive airway pressure treatment

Abstract: Abstract Study Objectives Untreated obstructive sleep apnea (OSA) is associated with cognitive deficits and altered brain electrophysiology. We evaluated the effect of continuous positive airway pressure (CPAP) treatment on quantitative sleep electroencephalogram (EEG) measures and cognitive function. Methods We studied 167 patients with OSA (age 50 ± 13, AHI 35.0 ± 26.8) before and after 6 months of CPAP. Cognitive tests assessed working memory, sustained attention, visuospatial scanning, and executive function. All participants underwent overnight polysomnography at baseline and after CPAP. Power spectral analysis was performed on EEG data (C3-M2) in a sub-set of 90 participants. Relative delta EEG power and sigma power in NREM and EEG slowing in REM were calculated. Spindle densities (events/min) in N2 were also derived using automated spindle event detection. All outcomes were analysed as change from baseline. Results Cognitive function across all cognitive domains improved after six months of CPAP. In our sub-set, increased relative delta power (p < .0001) and reduced sigma power (p = .001) during NREM were observed after the 6-month treatment period. Overall, fast and slow sleep spindle densities during N2 were increased after treatment. Conclusions Cognitive performance was improved and sleep EEG features were enhanced when assessing the effects of CPAP. These findings suggest the reversibility of cognitive deficits and altered brain electrophysiology observed in untreated OSA following six months of treatment.

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship

Abstract: Obstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.Mild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18-35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth. OSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose-response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Within-night Repeatability and Long-term Consistency of Sleep Apnea Endotypes: The Multi-Ethnic Study of Atherosclerosis and Osteoporotic Fractures in Men Study.

Abstract: STUDY OBJECTIVES Obstructive sleep apnea (OSA) is characterized by multiple "endotypic traits", including pharyngeal collapsibility, muscle compensation, loop gain, and arousal threshold. Here we examined 1) within-night repeatability, 2) long-term consistency, and 3) influences of body position and sleep state, of endotypic traits estimated from in-home polysomnography in mild-to-severe OSA (apnea-hypopnea index, AHI>5 events/hr). METHODS Within-night repeatability was assessed using Multi-Ethnic Study of Atherosclerosis (MESA): Traits derived separately from "odd" and "even" 30-min periods were correlated and regression (error vs. N windows available) provided a recommended amount of data for acceptable repeatability (R-threshold=0.7). Long-term consistency was assessed using the Osteoporotic Fractures in Men Study (MrOS) at two time points 6.5±0.7 years apart, before and after accounting for across-year body position and sleep state differences. Within-night dependence of traits on position and state (MESA plus MrOS data) were estimated using bootstrapping. RESULTS Within-night repeatability for traits ranged from R=0.62-0.79 and improved to R=0.69-0.83 when recommended amounts of data were available (20-35 seven-min windows, available in 94-98% of participants); repeatability was similar for collapsibility, loop gain, and arousal threshold (R=0.79-0.83), but lower for compensation (R=0.69). Long-term consistency was modest (R=0.30-0.61) and improved (R=0.36-0.63) after accounting for position and state differences. Position/state analysis revealed reduced loop gain in REM and reduced collapsbility in N3. CONCLUSIONS Endotypic traits can be obtained with acceptable repeatability. Long-term consistency was modest but improved after accounting for position and state changes. These data support the use of endotypic assessments in large-scale epidemiological studies.

Lucid Dreaming Occurs in Activated REM Sleep, Not a Mixture of Sleep and Wakefulness.

Abstract: STUDY OBJECTIVES 1) To replicate the finding that lucid dreams are associated with physiological activation, including heightened REM density, during REM sleep. 2) To critically test whether a previously reported increase in frontolateral 40 Hz power in lucid REM sleep, used to justify the claim that lucid dreaming is a "hybrid state" mixing sleep and wakefulness, is attributable to the saccadic spike potential (SP) artifact as a corollary of heightened REM density. 3) To conduct an exploratory analysis of changes in EEG features during lucid REM sleep. METHODS We analyzed 14 signal-verified lucid dreams (SVLDs) and baseline REM sleep segments from the same REM periods from six participants derived from the Stanford SVLD database. Participants marked lucidity onset with standard left-right-left-right-center (LR2c) eye-movement signals in polysomnography recordings. RESULTS Compared to baseline REM sleep, lucid REM sleep had higher REM density (p=0.002). Bayesian analysis supported the null hypothesis of no differences in frontolateral 40 Hz power after removal of the SP artifact (BH=0.18) and ICA correction (BH=0.01). Compared to the entire REM sleep period, lucid REM sleep showed small reductions in low-frequency and beta band spectral power as well as increased signal complexity (all p<0.05), which were within the normal variance of baseline REM sleep. CONCLUSIONS Lucid dreams are associated with higher-than-average levels of physiological activation during REM sleep, including measures of both subcortical and cortical activation. Increases in 40 Hz power in periorbital channels reflect saccadic and microsaccadic SPs as a result of higher REM density accompanying heightened activation.

Mandibular Movements are a Reliable Noninvasive Alternative to Esophageal Pressure for Measuring Respiratory Effort in Patients with Sleep Apnea Syndrome

Abstract: Differentiation between obstructive and central apneas and hypopneas requires quantitative measurement of respiratory effort (RE) using esophageal pressure (PES), which is rarely implemented. This study investigated whether the sleep mandibular movements (MM) signal recorded with a tri-axial gyroscopic chin sensor (Sunrise, Namur, Belgium) is a reliable surrogate of PES in patients with suspected obstructive sleep apnea (OSA).In-laboratory polysomnography (PSG) with PES and concurrent MM monitoring was performed. PSGs were scored manually using AASM 2012 rules. Data blocks (n=8042) were randomly sampled during normal breathing (NB), obstructive or central apnea/hypopnea (OA/OH/CA/CH), respiratory effort-related arousal (RERA), and mixed apnea (MxA). Analyses were evaluation of the similarity and linear correlation between PES and MM using the longest common subsequence (LCSS) algorithm and Pearson's coefficient; description of signal amplitudes; estimation of the marginal effect for crossing from NB to a respiratory disturbance for a given change in MM signal using a mixed linear-regression.Participants (n=38) had mild to severe OSA (median AH index 28.9/h; median arousal index 23.2/h). MM showed a high level of synchronization with concurrent PES signals. Distribution of MM amplitude differed significantly between event types: median (95% confidence interval) values of 0.60 (0.16-2.43) for CA, 0.83 (0.23-4.71) for CH, 1.93 (0.46-12.43) for MxA, 3.23 (0.72-18.09) for OH, and 6.42 (0.88-26.81) for OA. Mixed regression indicated that crossing from NB to central events would decrease MM signal amplitude by -1.23 (CH) and -2.04 (CA) units, while obstructive events would increase MM amplitude by +3.27 (OH) and +6.79 (OA) units (all p<10-6).In OSA patients, MM signals facilitated the measurement of specific levels of RE associated with obstructive, central or mixed apneas and/or hypopneas. A high degree of similarity was observed with the PES gold-standard signal.

Lucid dreaming occurs in activated rapid eye movement sleep, not a mixture of sleep and wakefulness.

Abstract: STUDY OBJECTIVES (1) To critically test whether a previously reported increase in frontolateral 40 Hz power in lucid REM sleep, used to justify the claim that lucid dreaming is a "hybrid state" mixing sleep and wakefulness, is attributable to the saccadic spike potential (SP) artifact as a corollary of heightened REM density. (2) To replicate the finding that lucid dreams are associated with physiological activation, including heightened eye movement density, during REM sleep. (3) To conduct an exploratory analysis of changes in EEG features during lucid REM sleep. METHODS We analyzed 14 signal-verified lucid dreams (SVLDs) and baseline REM sleep segments from the same REM periods from six participants derived from the Stanford SVLD database. Participants marked lucidity onset with standard left-right-left-right-center (LR2c) eye-movement signals in polysomnography recordings. RESULTS Compared to baseline REM sleep, lucid REM sleep had higher REM density (β = 0.85, p = 0.002). Bayesian analysis supported the null hypothesis of no differences in frontolateral 40 Hz power after removal of the SP artifact (BH = 0.18) and ICA correction (BH = 0.01). Compared to the entire REM sleep period, lucid REM sleep showed small reductions in low-frequency and beta band spectral power as well as increased signal complexity (all p < 0.05), which were within the normal variance of baseline REM sleep. CONCLUSIONS Lucid dreams are associated with higher-than-average levels of physiological activation during REM sleep, including measures of both subcortical and cortical activation. Increases in 40 Hz power in periorbital channels reflect saccadic and microsaccadic SPs as a result of higher REM density accompanying heightened activation.

Evaluation of drug-induced sleep endoscopy as a tool for selecting patients with obstructive sleep apnea for maxillomandibular advancement

Abstract: (1) To investigate if drug-induced sleep endoscopy (DISE) findings are predictive of surgical response for patients undergoing maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) and (2) to investigate the predictive value of the jaw thrust maneuver during DISE in terms of surgical response to MMA.A retrospective cohort study was conducted in patients with OSA who underwent a baseline polysomnography (PSG) and DISE followed by MMA and a 3- to 6-month follow-up PSG between September 1, 2011, and September 30, 2020.Sixty-four patients with OSA (50 males [78.1%]; mean ± SD age = 51.7 ± 9.5 years; mean ± SD apnea-hypopnea index = 49.0 ± 20.8 events/h) were included. Thirty-nine patients were responders, and 25 were nonresponders. Adjusting for baseline characteristics and surgical characteristics (eg, age, baseline apnea-hypopnea index, degree of maxillary advancement), patients with complete anteroposterior epiglottic collapse had 0.239 times lower odds for response to MMA (95% confidence interval, 0.059-0.979; P = .047). No significant relationship was found between complete concentric velum collapse and MMA response. There was no statistically significant association between effect of jaw thrust maneuver during DISE on upper airway patency and treatment outcome of MMA.This study indicates that DISE is a promising tool to identify patients who will or will not respond to MMA for treating OSA. Patients with complete anteroposterior epiglottic collapse may be less suitable candidates for MMA.Zhou N, Ho J-PTF, de Vries N, Bosschieter PFN, Ravesloot MJL, de Lange J. Evaluation of drug-induced sleep endoscopy as a tool for selecting patients with obstructive sleep apnea for maxillomandibular advancement. J Clin Sleep Med. 2022;18(4):1073-1081.