Cerebral blood flow in sleep: A systematic review and meta-analysis.

Sleep plays an essential role in physiology, allowing the brain and body to restore itself. Despite its critical role, our understanding of the underlying processes in the sleeping human brain is still limited. Sleep comprises several distinct stages with varying depths and temporal compositions. Cerebral blood flow (CBF), which delivers essential nutrients and oxygen to the brain, varies across brain regions throughout these sleep stages, reflecting changes in neuronal function and regulation. This systematic review and meta-analysis assesses global and regional CBF across sleep stages. We included, appraised, and summarized all 38 published sleep studies on CBF in healthy humans that were not or only slightly (<24 h) sleep deprived. Our main findings are that CBF varies with sleep stage and depth, being generally lowest in NREM sleep and highest in REM sleep. These changes appear to stem from sleep stage-specific regional brain activities that serve particular functions, such as alterations in consciousness and emotional processing.

Efficacy of occlusal splint versus sleep hygiene and progressive muscle relaxation on perceived stress and sleep bruxism: A randomized clinical trial.

PURPOSE: The objective was the comparison of an occlusal device (OD), and sleep hygiene and progressive muscle relaxation (SH & PMR) on perceived stress and sleep bruxism activity (burst/episode and episode/hour) in participants with sleep bruxism. MATERIAL AND METHODS: Sixty-six participants with self-reported sleep bruxism were selected and randomly allocated into two groups: OD group or SH & PMR group. Assessment of perceived stress and sleep bruxism activity were the primary outcomes. The Perceived Stress Scale-10 (PSS-10 scale) was used to measure perceived stress and bruxism episodes/hour and bursts/episode recorded by electromyography of masseter and temporalis. These outcomes were assessed at baseline, 1 month, 6 months, and 1 year. The paired t-test assessed changes in PSS-10 scores and sleep bruxism activity within the same group over different time points (baseline, 1 month, 6 months, and 1 year). The unpaired t-test compared scores between two groups (OD and SH & PMR) at each time point to evaluate intervention differences. The chi-square test compared gender distribution between both groups. RESULTS: PSS-10 scores were found to decrease with the OD at 1 month and 6 months compared to baseline and SH & PMR at all subsequent follow-ups. This decrease was not statistically significant (p > 0.05) between the OD and SH & PMR groups at all follow-ups. OD and SH & PMR significantly reduced bruxism episodes/hour and bursts/episode at all follow-ups (p < 0.05). There were no adverse effects related to any intervention. CONCLUSIONS: The OD and SH & PMR both effectively reduced PSS-10 scores over 6 months and significantly decreased bruxism episodes and bursts per episode. Both methods are safe and effective for managing sleep bruxism and reducing stress.

Exploring the Effects of Sensorimotor Training and Relaxation Therapy on Postural Control, Balance, Sleep, and Stress in Sedentary Young Adults: Rationale, Design, and Methodology.

Postural control (PC) and sleep are critical in several aspects of health. Poor sleep negatively influences PC and balance, which is necessary for performing various tasks, from reaching to mobility. Moreover, sleep disturbances and consequent PC and balance deterioration are associated with job accidents, traffic accidents, falls, and injuries. Healthy adults who have inadequate sleep show a decline in optimal functioning, even in the absence of medical illnesses. This suggests that getting enough sleep, both in duration and quality, is essential to maintain optimal health. Moreover, inadequate sleep has also been observed to have a bidirectional relationship with stress levels. However, there is insufficient evidence regarding the impact of non-pharmacological treatments to improve PC, sleep, and stress in the sedentary young adult (YA) population. This article describes the protocol for a study to investigate the effects of sensorimotor training and relaxation therapy on various static and dynamic PC tests, balance measures, and subjective and objective indices of sleep and stress among sedentary YAs with impaired sleep quality. The protocol is also designed to evaluate the effect of these therapies on fatigue, salivary cortisol levels, anxiety, and depression. Methods for assessing the sleep architecture, static and dynamic PC, balance, and stress are described along with the methods of scoring with the primary goal of providing a standardized set of assessment and scoring procedures according to the latest guidelines and gold-standard techniques and measures that can be used reliably at different laboratories. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Postural control assessment Basic Protocol 2: Balance assessment Basic Protocol 3: Sleep architecture assessment Basic Protocol 4: Salivary cortisol analysis.

Altered sleep and diurnal consequences in women with dysmenorrhea: study from the EPISONO database.

PURPOSE: Our study aimed to identify alterations in sleep, inflammatory mediators, fatigue and quality of life in women with dysmenorrhea and compare them to women without dysmenorrhea. METHODS: The sample comprised 328 women from a Brazilian cross-sectional sleep study, EPISONO (2007), who had undergone 1-night polysomnography (PSG) type I and completed questionnaires related to sleep quality, daytime sleepiness, insomnia, fatigue, anxiety, depression, and quality of life. Blood samples were used to assess levels of interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP). The 2 groups were distributed based on the presence or absence of dysmenorrhea symptoms. RESULTS: Sleep efficiency was significantly lower in the group of women with dysmenorrhea (82.5% ± 13.8) compared to the non-dysmenorrhea group (86.2% ± 10.9). Dysmenorrhea was associated with significantly higher scores of fatigue and worse scores in the physical quality of life. No statistical differences were detected in inflammatory markers between the 2 groups. DISCUSSION: Fatigue and physical quality of life were presented in women with dysmenorrhea, as was reduced sleep efficiency, although no alteration on inflammatory markers were observed. CONCLUSION: These findings show that dysmenorrhea can have a deleterious effect on women's sleep, with repercussions on daily routines and quality of life.

Challenges of Positive Airway Pressure Treatment for Patients With Obstructive Sleep Apnea at a Veterans Medical Center.

OBJECTIVE: Positive airway pressure (PAP) compliance is important in treating obstructive sleep apnea. Previous studies have suggested that patients with economic burdens, discomfort using machines, and insufficient education have difficulty tolerating PAP machines. This study explored the factors affecting short-term adherence to PAP in a veterans medical center. METHODS: The medical records of patients who underwent polysomnography at the Veterans Health Service Medical Center, Seoul, Republic of Korea, between July 2018 and January 2021 were reviewed retrospectively. Patients with an apnea-hypopnea index (AHI) ≥15 were included (n=579). PAP adherence was defined as continuous use for ≥21 days for ≥4 hours daily for 30 consecutive days for 90 days from the date of PAP prescription. RESULTS: The PAP-adherent group (n=265, age 66.16±11.28 years) was younger and had more years of education, higher body mass indices, and lower scores in the Insomnia Severity Index and Beck Depression Inventory-II (BDI-II) than those of the PAP-nonadherent group (n=314, age 68.93±10.91 years). Patients who tolerated PAP had a higher AHI, longer duration of oxygen desaturation (less than 90%), and less dream enactment behavior (DEB) than that in those who did not. After adjusting for age, years of education, BDI-II, duration of oxygen desaturation, and presence of DEB, there were more patients with National Health Insurance (NHI) in the PAP-adherent group than in the PAP-nonadherent group (p<0.001). CONCLUSION: We showed that patients with NHI recorded significantly higher adherence compared to that in patients without NHI, among other factors.

Persistent Obstructive Sleep Apnea Post-adenotonsillectomy in Children.

Background Childhood obstructive sleep apnea (OSA) is a common disorder in children mostly due to adenotonsillar hypertrophy. Therefore, adenotonsillectomy is the mainstay of treatment. However, the outcome of adenotonsillectomy is limited in some patients who develop persistent OSA (POSA). We aim to evaluate the prevalence, risk factors, and treatments of POSA in the pediatric population in Qatar. Methodology This is a retrospective review of medical electronic records of patients aged 1-18 years, who underwent adenoidectomy and/or tonsillectomy at Sidra Medicine (Doha, Qatar) between June 2017 and September 2022. Demographic, clinical, and polysomnography (PSG) data were collected. POSA was defined as the persistence of at least one of the following OSA symptoms: snoring, gasping, mouth breathing or witnessed sleep apnea during post-surgery clinic visits, and/or post-surgical diagnosis of OSA by PSG. The prevalence of POSA was defined as the number of patients who had persistent symptoms divided by patients who were followed at outpatient clinics (ENT/pulmonology) post-surgery. Risk factors for POSA were evaluated using multivariate regression analysis. Results A total of 410 patients (259 males and 151 females) underwent adenotonsillectomy during the study period. The average age at surgery was 3.6 ± 2.5 years. The majority of patients (85.9%) had no history of underlying medical conditions. The rest of the patients (14.1%) were diagnosed with chromosomal abnormalities or neuromuscular disorders. All patients (100%) had a history of snoring before surgery, and 32.4% of patients had a history of witnessed sleep apnea. A total of 52 patients had persistent symptoms four months post-surgery. POSA prevalence was estimated at 15.4%. Univariate analysis showed young age at the time of surgery (p = 0.015), history of asthma (23%, 12/52) (p = 0.002), allergic rhinitis (13%, 7/52) (p = 0.001), gastroesophageal reflux disease ((11%, 6/52) (p < 0.001), and genetic syndromes (17%, 9/52) (p < 0.005) as significant risk factors for POSA. Multiple regression analysis showed that syndromic disorders and allergic rhinitis were significantly correlated with persistent OSA (p = 0.021 and p = 0.000, respectively). Conclusions POSA is prevalent in children post-tonsillectomy and adenoidectomy, especially in patients with genetic syndromes and those with symptoms of allergic rhinitis. Future studies are needed to better define the condition and provide evidence-based diagnostic and therapeutic approaches.

Circadian Temperature in Moderate to Severe Acute Stroke Patients.

Background: Stroke patients often present circadian disruption due to multiple causes e.g., primary disease, comorbidities, medication, immobilization, reduced daylight entrainment and sleep disturbances. Objective: To investigate the circadian rhythm of temperature in forehead skin in patients with moderate to severe stroke admitted for rehabilitation. Methods: A physiologic study in form of a secondary analysis of a former randomized study. In total 27 patients with moderate to severe stroke were included between May 1st 2014, and June 1st 2015. Circadian temperature was collected approx. seven days after admission at the acute stroke unit by a skin surface temperature probe as part of a Polysomnography (PSG) measurement. Results: Temperature variations show no circadian rhythm (Type 3 tests of fixed effects by SAS, p = 0.1610). The median temperature variance did fluctuate, but not significantly, and the small changes in circadian temperature variance did not follow the normal temperature variance. Conclusion: Patients with moderate to severe stroke show an abrogated circadian rhythm of temperature. There is an unmet need to understand the mechanisms for this, significance for stroke outcome and treatment.

Rapid Eye Movements during REM Sleep Differentiate PSP from Parkinson's Disease.

BACKGROUND: Little is known about the characteristics and occurrence frequencies of rapid eye movements (REMs) during REM sleep in movement disorders. OBJECTIVES: The aim of this study was to detect and characterize REMs during polysomnographically defined REM sleep as recorded by electro-oculography (EOG) in 12 patients with progressive supranuclear palsy (PSP), 13 patients with Parkinson's disease (PD) and 12 healthy controls. METHODS: Using a modified EOG montage, we developed an algorithm that automatically detects and characterizes REMs during REM sleep based on their presumptive saccadic kinematics. RESULTS: Compared to PD and healthy controls, REM densities and REM peak velocities were significantly reduced in PSP. These effects were most pronounced in vertical REMs. CONCLUSION: Ocular motor dysfunction, one of the cardinal features of PSP, seems to be equally at play during REM sleep and wakefulness. For future studies, we provide a novel tool for the unbiased analysis of REMs during REM sleep in movement disorders.

The effect of central sleep apnea on sleep architecture in children with obstructive sleep apnea.

OBJECTIVE: This study aimed to investigate how central sleep apnea (CSA) impacts sleep patterns in children with obstructive sleep apnea (OSA). METHODS: Children undergoing polysomnography (PSG) were enrolled and sorted into two groups: those with OSA alone (Group A) and those with both OSA and CSA (CAI <1 nd: children with 10 % CSA or more and less than 50 %, Group B). Statistical analysis was conducted to compare sleep structure and clinical features between Group A and Group B. RESULTS: Group B exhibited significantly higher respiratory events, apnea hypoventilation index, apnea index and oxygen desaturation index (ODI) compared to Group A (p < 0.05). Group B also showed higher total sleep time and arousal index than Group A (P < 0.05). The proportion of time spent in stage N3 was lower in Group B than in Group A (P < 0.05). Moreover, mean heart rate and minimum heart rate were higher in Group B compared to Group A (P < 0.05).Minimum oxygenation levels (including non-rapid eye movement (NREM) stages) were lowe in Group B than in Group A (P < 0.05). Additionally, the prevalence of positional obstructive sleep apnea (P-OSA) was greater in Group B than in Group A (P < 0.05). CONCLUSION: In comparison to those with OSA alone, children with OSA and concurrent CSA exhibited distinct sleep patterns, including reduced N3uration, higher arousal index, longer respiratory events, higher ODI, and lower oxygen saturation, higher heart rate.

[Arrhythmia in sleep apnea]. / Arrhythmien bei Schlafapnoe.

BACKGROUND: Sleep apnea is a widespread and yet still underdiagnosed condition. Various studies from the past have provided evidence that there is a link between sleep apnea and various cardiovascular diseases, including arrhythmias. OBJECTIVE: The aim of this article is to provide an overview of the current study situation and to point out possible consequences relevant to everyday life. MATERIAL AND METHODS: A systematic search was carried out in various databases using the keywords sleep apnea (OSAS/SA) and arrhythmias/dysrhythmias. RESULTS: There are several pathophysiological links between sleep-related breathing disorders and cardiac arrhythmias, the most important of which appear to be intrathoracic pressure, increased adrenergic tone as well as recurrent hypoxia and hypercapnia. This results in an increased occurrence of clinically relevant arrhythmias, such as atrial fibrillation, symptomatic bradycardia, high-grade atrioventricular (AV) blocks as well as ventricular arrhythmias in patients with untreated sleep apnea. These pathologies also appear to be positively influenced by the treatment of sleep apnea. CONCLUSION: A close correlation between sleep apnea and cardiac arrhythmias is undisputed. Large randomized studies in this respect are so far rare but it is undisputed that a thorough search should be carried out for sleep apnea and consistently treated in patients with a history of cardiac disease as this can have a relevant influence on the treatment and ultimately the prognosis of the patient.

Improved sleep stage predictions by deep learning of photoplethysmogram and respiration patterns.

Sleep staging is a crucial tool for diagnosing and monitoring sleep disorders, but the standard clinical approach using polysomnography (PSG) in a sleep lab is time-consuming, expensive, uncomfortable, and limited to a single night. Advancements in sensor technology have enabled home sleep monitoring, but existing devices still lack sufficient accuracy to inform clinical decisions. To address this challenge, we propose a deep learning architecture that combines a convolutional neural network and bidirectional long short-term memory to accurately classify sleep stages. By supplementing photoplethysmography (PPG) signals with respiratory sensor inputs, we demonstrated significant improvements in prediction accuracy and Cohen's kappa (k) for 2- (92.7 %; k = 0.768), 3- (80.2 %; k = 0.714), 4- (76.8 %, k = 0.550), and 5-stage (76.7 %, k = 0.616) sleep classification using raw data. This relatively translatable approach, with a less intensive AI model and leveraging only a few, inexpensive sensors, shows promise in accurately staging sleep. This has potential for diagnosing and managing sleep disorders in a more accessible and practical manner, possibly even at home.

Sleep-related bruxism, microarousals and oxyhaemoglobin desaturations in sleep stages: A cross-sectional study in a large apnoeic population.

BACKGROUND: Sleep-related bruxism (SB) is the habit of grinding or clenching the teeth during sleep, mediated by the non-peripheral central nervous system. PURPOSE: The objectives of this cross-sectional study were to evaluate associations between SB, microarousals and oxyhaemoglobin desaturations and to compare the frequency of SB and microarousals in sleep stages, in an apnoeic population. METHODS: Two hundred and forty individuals composed the sample, who underwent a single full-night polysomnography. Self-reports and clinical inspections were not considered for assessing SB. The polysomnographic assessment of SB was performed using electrodes placed on masseter muscles and chin. SB was defined as more than two events of rhythmic masticatory muscle activity per hour of sleep. Microarousals were considered when there were abrupt changes in electroencephalogram frequencies, without complete awakening, lasting from 3 to 15 s. Oxyhaemoglobin desaturations were defined as significant drops (≥3%) in basal oxygen saturations. With these data, SB, microarousals and oxyhaemoglobin desaturations were evaluated and submitted to statistical analysis. RESULTS: Statistically significant differences were observed between bruxers and non-bruxers when comparing the rates of microarousals (p < .001) and oxyhaemoglobin desaturations (p = .038). There was a higher number of SB and microarousals in NREM (non-rapid eye movement) two sleep stage (p < 0.001). Bruxers had a greater risk of higher numbers of microarousals (OR = 1.023; p = .003), which did not occur for oxyhaemoglobin desaturations (OR = 0.998; p = .741). CONCLUSIONS: A higher number of microarousals presents relationship with SB; associations between SB and oxyhaemoglobin desaturations remained inconclusive; higher frequency of SB and microarousals was observed in NREM 2 sleep stage.

Comparison of automated deep neural network against manual sleep stage scoring in clinical data.

OBJECTIVE: To compare the accuracy and generalizability of an automated deep neural network and the Philip Sleepware G3™ Somnolyzer system (Somnolyzer) for sleep stage scoring using American Academy of Sleep Medicine (AASM) guidelines. METHODS: Sleep recordings from 104 participants were analyzed by a convolutional neural network (CNN), the Somnolyzer and skillful technicians. Evaluation metrics were derived for different combinations of sleep stages. A further comparison between the Somnolyzer and the CNN model using a single-channel signal as input was also performed. Sleep recordings from 263 participants with a lower prevalence of OSA served as a cross-validation dataset to validate the generalizability of the CNN model. RESULTS: The overall agreement between automated and manual scoring for sleep staging in 104 participants outperformed that of the Somnolyzer according to various metrics (accuracy: 81.81 % vs. 77.07 %; F1: 76.36 % vs. 73.80 %; Cohen's kappa: 0.7403 vs. 0.6848). The results showed that the left electrooculography (EOG) single-channel model had minor advantages over the Somnolyzer. In terms of consistency with manual sleep staging, the CNN model demonstrated superior performance in identifying more pronounced sleep transitions, particularly in the N2 stage and sleep latency metrics. Conversely, the Somnolyzer showed enhanced proficiency in the analysis of REM stages, notably in measuring REM latency. The accuracy in the cross-validation set of 263 participants was also above 80 %. CONCLUSIONS: The CNN-based automated deep neural network outperformed the Somnolyzer and is sufficiently accurate for sleep study analyses using the AASM classification criteria.

The role of objective sleep in implicit and explicit affect regulation: A comprehensive review.

Impairments in sleep and affect regulation are evident across a wide range of mental disorders. Understanding the sleep factors that relate to affect regulatory difficulties will inform mechanistic understanding and aid in treatment. Despite rising interest, some research challenges in this area include integrating across different clinical and non-clinical literatures investigating the role of sleep architecture (measured with polysomnography) and experimentally manipulated sleep, as well as integrating more explicit versus implicit affect regulation processes. In this comprehensive review, we use a unifying framework to examine sleep's relationship with implicit-automatic regulation and explicit-controlled regulation, both of which are relevant to mental health (e.g., PTSD and depression). Many studies of implicit-automatic regulation (e.g., fear extinction and safety learning) demonstrate the importance of sleep, and REM sleep specifically. Studies of explicit-controlled regulation (e.g., cognitive reappraisal and expressive suppression) are less consistent in their findings, with results differing depending on the type of affect regulation and/or way that sleep was measured or manipulated. There is a clear relationship between objective sleep and affect regulation processes. However, there is a need for 1) more studies focusing on sleep and explicit-controlled affect regulation; 2) replication with the same types of regulation strategies; 3) more studies experimentally manipulating sleep to examine its impact on affect regulation and vice versa in order to infer cause and effect; and 4) more studies looking at sleep's impact on next-day affect regulation (not just overnight change in affect reactivity).

The Incidence of Obstructive Sleep Apnea in Patients with Dento-Skeletal Malformation.

Purpose: The aim of this article is to analyze the incidence of undiagnosed obstructive sleep apnea (OSA) in patients affected by dento-skeletal malformation. We also evaluated the patterns most affected by the condition and calculated the post surgical changes. Methods: We conducted a retrospective cohort study on 71 patients including 35 men and 36 women. The patients studied were affected by dento-skeletal class II and III malformations and underwent bimaxillary orthognathic surgery in all cases. Patients were evaluated with polysomnography before surgery and at least 6 months after surgery to assess any improvement or worsening of the apnea hypopnea index (AHI) index. Regarding AHI evaluation criteria, an AHI > 5 was considered indicative of OSA, 4 < AHI < 5 was considered borderline and AHI < 4 was considered indicative of non-OSA. We also considered demographic variables like age at the time of intervention and gender, and anatomical variables like the pattern of the dento-skeletal deformity and the presence or absence of maxillary hypoplasia. Qualitative variables were described as absolute and relative frequencies, while quantitative variables were summarized as mean and standard deviation. To quantitatively express the relationship between two variables, the correlation coefficient was calculated. The covariance array was used to evaluate multiple correlations. Results: Our study shows that there is a significant percentage (33%) of patients who undergo orthognathic surgery with an AHI > 5 and also a percentage of patients (11%) who can be considered to be "borderline." It emerges that the pattern most at risk is the one characterized by retruded maxilla and patients with dento-skeletal class II. Considering the post surgical period, the statistical analysis shows that after surgery, only 8% of malformed patients present an AHI > 5, compared to the 20.5% described in the Italian population. Conclusions: In patients who receive orthognathic surgery, the presence of obstructive sleep apnea is significantly higher than in the general population. When planning the surgical correction of a dento-skeletal malformation, the surgeon must aim not only for the esthetics results, but also for proper stomatognathic and respiratory function; this cannot be achieved without taking polysomnography information into account.

Objective sleep enhancement in Parkinson's disease: A sham-controlled trial of low-frequency repetitive transcranial magnetic stimulation over the right dorsolateral prefrontal cortex.

INTRODUCTION: Parkinson's disease (PD) is often accompanied by sleep disturbances, impacting patients' quality of life. While repetitive transcranial magnetic stimulation (rTMS) shows promise in improving self-reported sleep quality, its effects on objective sleep architecture in PD remain understudied. Sleep disturbances, including rapid eye movement (REM) and slow-wave sleep disturbances, correlate with cognitive decline and motor symptoms. This study investigated the effect of low-frequency rTMS targeting the right dorsolateral prefrontal cortex (DLPFC) modifying objective sleep architecture and explored symptom improvement mechanisms in PD patients. METHODS: In this randomized, double-blind, sham-controlled trial, 67 PD patients received 10 consecutive days of 1-Hz rTMS over the right DLPFC. Polysomnography assessed sleep microstructure, while electroencephalogram recordings evaluated power spectral density and sleep spindle activity. Clinical scales measured sleep quality, motor symptoms, and cognition at baseline, post-treatment, and 3 months post-rTMS. RESULTS: The rTMS group exhibited improvements in sleep quality, motor symptoms, and cognition post-treatment, persisting at the 3-month follow-up. There was a notable increase in the REM sleep proportion post-rTMS. The rTMS group exhibited elevated low-frequency (0.5-2 Hz) slow-wave electroencephalogram spectral density during non-REM sleep. Cognitive enhancement correlated with increased lower delta power, while motor symptom progression correlated with spindle frequency and slow-wave sleep percentage changes. CONCLUSION: Low-frequency rTMS targeting the right DLPFC holds promise for improving clinical symptoms and modulating sleep architecture in PD. These findings suggest a link between symptom improvement and sleep structure enhancement, highlighting the need for further investigation into the therapeutic potential of rTMS in PD management.

An Inertial-Based Wearable System for Monitoring Vital Signs during Sleep.

This study explores the feasibility of a wearable system to monitor vital signs during sleep. The system incorporates five inertial measurement units (IMUs) located on the waist, the arms, and the legs. To evaluate the performance of a novel framework, twenty-three participants underwent a sleep study, and vital signs, including respiratory rate (RR) and heart rate (HR), were monitored via polysomnography (PSG). The dataset comprises individuals with varying severity of sleep-disordered breathing (SDB). Using a single IMU sensor positioned at the waist, strong correlations of more than 0.95 with the PSG-derived vital signs were obtained. Low inter-participant mean absolute errors of about 0.66 breaths/min and 1.32 beats/min were achieved, for RR and HR, respectively. The percentage of data available for analysis, representing the time coverage, was 98.3% for RR estimation and 78.3% for HR estimation. Nevertheless, the fusion of data from IMUs positioned at the arms and legs enhanced the inter-participant time coverage of HR estimation by over 15%. These findings imply that the proposed methodology can be used for vital sign monitoring during sleep, paving the way for a comprehensive understanding of sleep quality in individuals with SDB.

Derivative Method to Detect Sleep and Awake States through Heart Rate Variability Analysis Using Machine Learning Algorithms.

Sleep disorders can have harmful consequences in both the short and long term. They can lead to attention deficits, as well as cardiac, neurological and behavioral repercussions. One of the most widely used methods for assessing sleep disorders is polysomnography (PSG). A major challenge associated with this method is all the cables needed to connect the recording devices, making the examination more intrusive and usually requiring a clinical environment. This can have potential consequences on the test results and their accuracy. One simple way to assess the state of the central nervous system (CNS), a well-known indicator of sleep disorder, could be the use of a portable medical device. With this in mind, we implemented a simple model using both the RR interval (RRI) and its second derivative to accurately predict the awake and napping states of a subject using a feature classification model. For training and validation, we used a database providing measurements from nine healthy young adults (six men and three women), in which heart rate variability (HRV) associated with light-on, light-off, sleep onset and sleep offset events. Results show that using a 30 min RRI time series window suffices for this lightweight model to accurately predict whether the patient was awake or napping.

Changes in slow-wave sleep characteristics in Parkinson's disease patients with mild-moderate depression.

INTRODUCTION: Depression and sleep disturbances are commonly seen non-motor symptoms in patients with Parkinson's disease (PD). This study used polysomnography to examine the relationship between mild-moderate depression in PD and sleep characteristics, particularly slow wave activities (SWA). METHODS: 59 PD patients were split into two groups: nd-PD (n = 27) (patients with PD without depression) and d-PD (n = 32) (patients with PD with mild-moderate depression). Their clinical features, polysomnography parameters, and demographics were evaluated. Early and late sleep SWA spectrum densities and overnight SWA decline in different brain regions were particularly analyzed. RESULTS: Non-rapid eye movement 3 (N3) sleep duration and percentage were greater in the d-PD group. N3 percentage was linked to depression (p = 0.014). During late sleep, higher SWA (0.5-4Hz) in the frontal and central regions, higher low-SWA (0.5-2Hz) in the whole brain, central and occipital regions, and higher high-SWA (2-4Hz) in the frontal region was observed in the d-PD group. During early sleep, there was also higher low-SWA (0.5-2Hz) in the occipital region. Patients in d-PD group exhibited reduced overnight high-SWA (2-4Hz) decline (Δhigh-SWA) in the whole brain and occipital regions. Δhigh-SWA(2-4Hz) in the occipital region were associated with depression (p = 0.049). CONCLUSION: PD patients with mild-moderate depression have impaired slow wave sleep, exhibiting as increased N3 sleep, SWA, and reduced overnight SWA decline. This implies that synaptic strength reduction during sleep and impaired synaptic homeostasis regulation may be associated with depression in PD. Reduced overnight high-SWA decline in the occipital region may serve as a novel electrophysiological biomarker for indicating depression in PD.

Risk Factors of Obstructive Sleep Apnea (OSA) in Pediatric Patients: A Systematic Review and Meta-analysis.

INTRODUCTION: This review aimed to assess the risk factors of Obstructive Sleep Apnea (OSA) in pediatric children, a common condition with serious long-term sequela. METHODS: PubMed, CENTRAL, Scopus, and Google Scholar were searched using the keywords "Apnea", "Obstructive Sleep" OR "Obstructive Sleep Apnea Syndrome" AND "Child" OR "Children" OR "Pediatrics". Data from 35 studies involving 497,688 pediatric patients diagnosed with OSA using polysomnography were reviewed. Risk factors examined included sex, obesity, neck circumference, tonsillar/adenoid hypertrophy, respiratory infections, nasal stenosis, parental OSA/smoking, ethnicity, preterm birth, and breastfeeding history. Relative Risk (RR) with 95% Confidence Intervals (95% CI) were calculated, using Cochrane Q and I² statistics to estimate heterogeneity. RESULTS: Tonsillar hypertrophy (RR = 3.55), adenoid hypertrophy (RR = 1.63), respiratory tract infection (RR = 2.59), obesity (RR = 1.74), and family history of OSA (RR = 3.03) were significantly associated with pediatric OSA. White ethnicity was protective (RR = 0.77). DISCUSSION: Recognizing these risk factors aids in early diagnosis and treatment of pediatric OSA.