Normative values of polysomnographic parameters in childhood and adolescence: quantitative sleep parameters

Polysomnographically Defined Restless Sleep Disorder and Periodic Limb Movements during Sleep in Children Born Prematurely

INTRODUCTION

Children born prematurely (<37 weeks' gestation) are at increased risk of perinatal complications, comorbidities, and iron deficiency. Iron deficiency is associated with restless legs syndrome and periodic limb movement disorder. In this study, we assessed the prevalence of restless sleep disorder (RSD) and elevated periodic limb movements during sleep (PLMS) in children born prematurely who underwent polysomnography.

METHODS

A retrospective chart review of sleep studies was conducted in children aged 1-18 years (median age 4 years) with a history of premature birth. Children with genetic syndrome, airway surgery, or tracheostomy were excluded. Three groups were compared: children with PLMS index >5, children with RSD, and children with neither elevated PLMS index nor RSD.

RESULTS

During the study, 2577 sleep studies were reviewed. Ninety-two studies fit our criteria and were included in the analysis. The median age at birth was 31 weeks, and the interquartile range (IQR) was 27-34 weeks. A total of 32 (34.8%) children were referred for restless sleep and 55 (59.8%) for snoring. After polysomnography, 18% were found to have a PLMS index >5/h, and 14% fit the criteria for restless sleep disorder (RSD). There were no statistically significant differences in PSG parameters among the children with RSD, PLMS, and the remaining group, except for lower obstructive apnea/hypopnea index (Kruskal-Wallis ANOVA 8.621, p = 0.0135) in the RSD group (median 0.7, IQR 0.3-0.9) than in the PLMS (median 1.7, IQR 0.7-3.5) or the non-RSD/non-PLMS (median 2.0, IQR 0.8-4.5) groups.

CONCLUSIONS

There was an elevated frequency of RSD and elevated PLMS in our cohort of children born prematurely. Children born prematurely are at higher risk of iron deficiency which can be a contributor factor to sleep -related movement disorders. These results add new knowledge regarding the prevalence of RSD and PLMS in these children.

Sleep bruxism and associated physiological events in children with obstructive sleep apnea: a polysomnographic study

STUDY OBJECTIVES

The aim of this study was to evaluate the physiological events associated with sleep bruxism (Sleep Bruxism [SB]; presence of mandibular movement activity) and the control window (4 minutes prior to SB event, where no mandibular movement activity was detected) in a polysomnography study in children with mild sleep apnea.

METHODS

Polysomnography data from children aged 4 to 9 years old diagnosed with mild sleep apnea were analyzed by 2 trained examiners. The mandibular movement activity (bruxism event; SB) was classified into phasic and tonic. The control window was selected 4 minutes prior to the SB event. All physiological events were recorded in both bruxism and control windows, including sleep phase (N1, N2, N3, and rapid eye movement), arousal, leg movements, tachycardia, bradycardia, oxygen desaturation, and number of obstructive and central sleep apnea events. The moment in which those phenomena occurred when associated with SB was also analyzed (before/after). Data were analyzed using 95% confidence intervals (α = 5%).

RESULTS

A total of 661 mandibular movements were analyzed and classified as tonic (n = 372) or phasic (n = 289). The mean apnea-hypopnea index was 1.99 (SD = 1.27) events/h. The frequency of leg movements, microarousal, and tachycardia was increased in SB events when compared with the control window (P < .05). There was an increase in bradycardia frequency in the control window when compared with SB (in both tonic and phasic events). The frequency of obstructive and central apnea during SB was lower when compared with the other physiological phenomena.

CONCLUSIONS

There is a difference in the physiological parameters evaluated in children with mild sleep apnea when comparing the 2 windows (SB and control). Sleep bruxism is associated with other physiological phenomena, such as leg movements, tachycardia, and microarousal. The use of a control window (where no mandibular activity was detected) was representative since it did not show activation of the sympathetic nervous system.

CITATION

Bonacina CF, Soster LMSFA, Bueno C, et al. Sleep bruxism and associated physiological events in children with obstructive sleep apnea: a polysomnographic study. J Clin Sleep Med. 2024;20(4):565-573.

Fundamentals of sleep regulation: Model and benchmark values for fractal and oscillatory neurodynamics

Homeostatic, circadian and ultradian mechanisms play crucial roles in the regulation of sleep. Evidence suggests that ratios of low-to-high frequency power in the electroencephalogram (EEG) spectrum indicate the instantaneous level of sleep pressure, influenced by factors such as individual sleep-wake history, current sleep stage, age-related differences and brain topography characteristics. These effects are well captured and reflected in the spectral exponent, a composite measure of the constant low-to-high frequency ratio in the periodogram, which is scale-free and exhibits lower interindividual variability compared to slow wave activity, potentially serving as a suitable standardization and reference measure. Here we propose an index of sleep homeostasis based on the spectral exponent, reflecting the level of membrane hyperpolarization and/or network bistability in the central nervous system in humans. In addition, we advance the idea that the U-shaped overnight deceleration of oscillatory slow and fast sleep spindle frequencies marks the biological night, providing somnologists with an EEG-index of circadian sleep regulation. Evidence supporting this assertion comes from studies based on sleep replacement, forced desynchrony protocols and high-resolution analyses of sleep spindles. Finally, ultradian sleep regulatory mechanisms are indicated by the recurrent, abrupt shifts in dominant oscillatory frequencies, with spindle ranges signifying non-rapid eye movement and non-spindle oscillations - rapid eye movement phases of the sleep cycles. Reconsidering the indicators of fundamental sleep regulatory processes in the framework of the new Fractal and Oscillatory Adjustment Model (FOAM) offers an appealing opportunity to bridge the gap between the two-process model of sleep regulation and clinical somnology.

An electroencephalography-based sleep index and supervised machine learning as a suitable tool for automated sleep classification in children

STUDY OBJECTIVES

Although sleep is frequently disrupted in the pediatric intensive care unit, it is currently not possible to perform real-time sleep monitoring at the bedside. In this study, spectral band powers of electroencephalography data are used to derive a simple index for sleep classification.

METHODS

Retrospective study at Erasmus MC Sophia Children's Hospital, using hospital-based polysomnography recordings obtained in non-critically ill children between 2017 and 2021. Six age categories were defined: 6-12 months, 1-3 years, 3-5 years, 5-9 years, 9-13 years, and 13-18 years. Candidate index measures were derived by calculating spectral band powers in different frequent frequency bands of smoothed electroencephalography. With the best performing index, sleep classification models were developed for two, three, and four states via decision tree and five-fold nested cross-validation. Model performance was assessed across age categories and electroencephalography channels.

RESULTS

In total 90 patients with polysomnography were included, with a mean (standard deviation) recording length of 10.3 (1.1) hours. The best performance was obtained with the gamma to delta spectral power ratio of the F4-A1 and F3-A1 channels with smoothing. Balanced accuracy was 0.88, 0.74, and 0.57 for two-, three-, and four-state classification. Across age categories, balanced accuracy ranged between 0.83 and 0.92 and 0.72 and 0.77 for two- and three-state classification, respectively.

CONCLUSIONS

We propose an interpretable and generalizable sleep index derived from single-channel electroencephalography for automated sleep monitoring at the bedside in non-critically ill children ages 6 months to 18 years, with good performance for two- and three-state classification.

CITATION

van Twist E, Hiemstra FW, Cramer ABG, et al. An electroencephalography-based sleep index and supervised machine learning as a suitable tool for automated sleep classification in children. J Clin Sleep Med. 2024;20(3):389-397.

Correlations between sleep architecture and sleep-related masseter muscle activity in children with sleep bruxism

BACKGROUND

Sleep bruxism (SB) occurring during No-REM (nREM) sleep and increase in microarousals per hour have been described in adults, but not in children.

OBJECTIVE

To assess the correlation between sleep architecture and masseter muscle activity related to sleep bruxism (SB/MMA) in children.

MATERIALS AND METHODS

Forty-three children aged 7-12 years (mean age: 9.4 ± 1.3) with confirmed SB underwent a two-night polysomnographic (PSG) study in a sleep laboratory, for accommodation (first night) and data collection (second night). Data on sleep architecture (total sleep duration (TSD), sleep efficiency (SE), sleep onset latency (SOL), REM and nREM sleep duration and proportion and microarousals/hour during REM and nREM sleep) and episodes/hour of SB/MMA were recorded. Single and multiple-variable linear regression analyses were performed to assess the correlation between data on sleep architecture (predictors) and SB/MMA (dependent variable).

RESULTS

Shorter TSD, REM and nREM stage 1 sleep duration, longer SOL and more microarousals/hour during REM and nREM sleep were found to be positive predictors of SB/MMA in children in the multiple-variable regression analysis (R2  = 0.511).

CONCLUSION

Within the limitations of this study, it can be concluded that SB/MMA is correlated with altered sleep architecture in children (shorter total sleep duration (TSD), shorter nREM and REM sleep and higher microarousals during REM and nREM sleep). Nevertheless, the clinical significance of these findings need to be demonstrated in future studies.

Mapping neurodevelopment with sleep macro- and micro-architecture across multiple pediatric populations

Profiles of sleep duration and timing and corresponding electroencephalographic activity reflect brain changes that support cognitive and behavioral maturation and may provide practical markers for tracking typical and atypical neurodevelopment. To build and evaluate a sleep-based, quantitative metric of brain maturation, we used whole-night polysomnography data, initially from two large National Sleep Research Resource samples, spanning childhood and adolescence (total N = 4,013, aged 2.5 to 17.5 years): the Childhood Adenotonsillectomy Trial (CHAT), a research study of children with snoring without neurodevelopmental delay, and Nationwide Children's Hospital (NCH) Sleep Databank, a pediatric sleep clinic cohort. Among children without neurodevelopmental disorders (NDD), sleep metrics derived from the electroencephalogram (EEG) displayed robust age-related changes consistently across datasets. During non-rapid eye movement (NREM) sleep, spindles and slow oscillations further exhibited characteristic developmental patterns, with respect to their rate of occurrence, temporal coupling and morphology. Based on these metrics in NCH, we constructed a model to predict an individual's chronological age. The model performed with high accuracy (r = 0.93 in the held-out NCH sample and r = 0.85 in a second independent replication sample - the Pediatric Adenotonsillectomy Trial for Snoring (PATS)). EEG-based age predictions reflected clinically meaningful neurodevelopmental differences; for example, children with NDD showed greater variability in predicted age, and children with Down syndrome or intellectual disability had significantly younger brain age predictions (respectively, 2.1 and 0.8 years less than their chronological age) compared to age-matched non-NDD children. Overall, our results indicate that sleep architectureoffers a sensitive window for characterizing brain maturation, suggesting the potential for scalable, objective sleep-based biomarkers to measure neurodevelopment.

The relationship between alexithymia, emotion regulation, and sleep problems in school-aged children: A multicentric study

OBJECTIVES

Alexithymia, mood dysregulation, and sleep quality have complicated effects on children's development. The current study aimed to investigate the relationship between alexithymia, emotion regulation, psychiatric problems, and sleep problems among Egyptian school-aged children.

METHODS

A total of 564 Egyptian children, aged 6 to 14, were divided into two groups based on their total Children's Sleep Habits Questionnaire abbreviated score: group 1 (N = 300) with sleep problems and group 2 (N = 264) with non-sleep problems. Their parents completed the Strengths and Difficulties Questionnaire (SDQ) and subjectively assessed the children's emotions using the Children's Alexithymia Measure (CAM) and the Clinical Evaluation of Emotional Regulation-9 (CEER-9).

RESULTS

Males were more proportional in the sleep problems group than others. The sleep problem group was significantly younger and had a longer daily sleep duration than the non-sleep problem group. Alexithymia and emotion dysregulation had the highest mean in the sleep problem group. Furthermore, alexithymia, emotion dysregulation, emotion difficulty, conduct, and prosocial problems were the most significant contributing factors and risk factors for sleep problems in children.

CONCLUSION

Sleep problems in children were associated with younger male children with lengthy daily sleep duration and emotional, behavioural, and prosocial difficulties. Furthermore, alexithymia and emotion dysregulation are significant contributors and risk factors for sleep problems in school-aged children.

Altered sleep architecture in children and adolescents with Down syndrome

OBJECTIVE

Children with Down syndrome (DS) may experience changes in sleep architecture (i.e., different sleep stages) that then affect waketime functioning, including learning, mood, and disruptive behavior. For designing and testing interventions, it is important to document any differences in sleep architecture in children with DS with and without co-occurring diagnoses, including neuropsychiatric diagnoses and obstructive sleep apnea (OSA).

METHODS

A retrospective cohort study was performed at Massachusetts General Hospital for children and adolescents with DS who underwent polysomnography (PSG) between August 2016 and July 2022. Patient data collected from the electronic medical record included diagnoses, age at PSG, and PSG report. Statistical analysis included unpaired T tests to test hypotheses about differences in sleep architecture within age groups, and differences between children with DS and a co-occurring diagnosis. One way ANOVA was used to determine statistical significance of OSA severity within patients with DS.

RESULTS

When compared by age group, those with DS had negative changes in sleep architecture (e.g., less sleep and more wake) when compared to normative data. Within this cohort, having a co-occurring diagnosis of autism resulted in further, negative effects on sleep architecture. 89% of those with DS had diagnosed OSA but only those with severe OSA experienced negative effects on sleep architecture.

CONCLUSION

Age is an important covariate when studying the sleep of children with DS and neurotypical children. Studies are needed to test whether minimizing the observed differences in sleep architecture will translate to improved learning, mood, and behavioral outcomes, and how treating OSA affects sleep architecture.

Two nights of home polysomnography in healthy 7-14-year-old children - Feasibility and intraindividual variability

OBJECTIVE

Attended polysomnography (PSG) is the gold standard for childhood sleep evaluation. There is, however, only limited information regarding repeated ambulatory PSG in children. We aimed to test whether in hospital attached level 2 home PSG is feasible and reproducible in healthy children.

METHODS

We recruited healthy children aged 7-14 years to undergo two nights of full level 2 PSG. The PSG equipment was attached at the hospital on the day of the sleep test and all recordings were performed at home. Subjective sleep quality, nocturnal urine production, sleep time and number of awakenings were documented for a week in connection to the first PSG night.

RESULTS

Thirty-three children were recruited of whom 32 children (aged 11 ± 2.1 years) underwent two nights of PSG. All 64 PSGs were technically adequate for sleep evaluation. We found mean sleep efficiency of 94% and mean total sleep time of 8.4 h. Sleep stages distribution with 5.9% N1, 46.8% N2, 24.3% N3 and 22.8% REM sleep. We found poorer subjective sleep quality, more self-reported awakenings, and shorter total sleep time on nights with PSG compared to nights without PSG with no differences between PSG study nights. No differences in nocturnal urine production were found between nights with and without PSG. The comparison of PSG variables between the two PSG nights revealed no first night effect.

CONCLUSIONS

Type 2 PSG recording is feasible for sleep evaluation in children 7-14 years of age producing good data quality. We found no first night effect on PSG variables. www.

CLINICALTRIALS

gov Registration number: NCT03477812.

An investigation of the sleep macrostructure of girls with Rett syndrome

OBJECTIVE/BACKGROUND

Methyl-CpG-binding protein 2 (MeCP2) is of utmost importance in neuronal function. We aim to characterize phenotypic traits in the sleep of individuals with Rett Syndrome (RTT, OMIM # 312750), a rare disorder predominantly caused by mutations of the MECP2 gene.

PATIENTS/METHODS

An overnight polysomnographic recording was performed. Outcomes investigated were parameters of nocturnal sleep macrostructure, and sample stratification per genetic and clinical characteristics, and six key features of clinical severity was applied.

RESULTS

The sleep of our 21 RTT female subjects with a mutant MECP2 gene, aged 8.8 ± 5.4 years, showed no significant differences within strata. However, compared to a normative dataset, we found longer duration of wake time after sleep onset and total sleep time (TST) but shorter sleep onset latency, in RTT. Regarding the proportion of sleep stages per TST, higher stage N3 (%) with lower stage N2 (%) and REM (%) were generally seen. Such abnormalities became more uniformly expressed at the severe level of clinical features, particularly for hand functioning and walking.

CONCLUSIONS

RTT girls with MECP2 mutations in our study demonstrated an increased deep sleep and reduced rapid eye movement sleep proportion, which is mostly allied with their hand dysfunction severity. Poor sleep-on/off switching in RTT since embryogenesis is possibly linked to (psycho)motor impairment in the cases with MECP2 mutations.

Season is related to the slow wave and sigma activity of infants and toddlers

OBJECTIVE/BACKGROUND

Slow wave activity (SWA) and sigma frequency activity (SFA) are hallmarks of NREM sleep EEG and important indicators of neural plasticity, development of the central nervous system, and cognition. However, little is known about the factors that modulate these sleep EEG activities, especially in small children.

PATIENTS/METHODS

We analyzed the power spectral densities of SWA (1-4 Hz) and SFA range (10-15 Hz) from six EEG derivations of 56 infants (8 months) and 60 toddlers (24 months) during their all-night sleep and during the first and the last half of night sleep. The spectral values were compared between the four seasons.

RESULTS

In the spring group of infants, compared with the darker seasons, SFA was lower in the centro-occipital EEG derivations during both halves of the night. The SWA findings of the infants were restricted to the last half of the night (SWA2) and frontally, where SWA2 was higher during winter than spring. The toddlers presented less frontal SWA2 during winter compared with autumn. Both age groups showed a reduction in both SWA and SFA towards the last half of the night.

CONCLUSIONS

The sleep EEG spectral power densities are more often associated with seasons in infants' SFA range. The results might stem from seasonally changing light exposure, but the exact mechanism warrants further study. Moreover, contrary to the adult-like increment of SFA, the SFA at both ages was lower at the last part of the night sleep. This suggests different regulation of spindle activity in infants and toddlers.

Sleep and Breathing Disturbances in Children With Leigh Syndrome: A Comparative Study

BACKGROUND

Leigh syndrome (LS) is a progressive neurodegenerative mitochondrial disease characterized by necrotizing lesions affecting different parts of the central nervous system, especially in the brainstem and basal ganglia. Lesions in this area may involve respiratory and sleep centers, resulting in the clinically significant disturbances seen-but poorly characterized-in LS. The purpose of the present study is to characterize and compare the physiologic responses to respiratory disturbances quantified by polysomnography metrics of children with LS with age-sex- and apnea-hypopnea index (AHI)-matched patients with obstructive sleep apnea (OSA), a common clinical population with similar burden of sleep-disordered breathing.

METHODS

Retrospective comparative study of polysomnographic data from six patients with LS were reviewed and compared with 18 age-sex-AHI-matched patients with OSA, with particular attention to cardiorespiratory and sleep architecture metrics.

RESULTS

Sleep architecture and stage duration were conserved in LS and OSA groups, but increased wake after sleep onset was seen among the first group. The LS group exhibited both obstructive and central sleep apnea. The group also had significantly greater values of heart rate, ≥3% oxygen desaturation index, and lower values of sleep efficiency, respiratory arousal index, and total sleep time when compared with the OSA group.

CONCLUSIONS

Patients with LS exhibited significantly more sleep-related cardiorespiratory disturbances and sleep fragmentation when compared with neurotypical children with OSA. Given that these findings are plausibly detrimental to health and development, sleep evaluation in patients with similar conditions should be encouraged for early management.

A meta-review of standard polysomnography parameters in Rett Syndrome

Rett Syndrome (RTT, OMIM 312750), a unique rare neurodevelopmental disorder, mostly affects females and causes severe multi-disabilities including poor sleep. This meta-analysis systematically reviewed the polysomnographic (PSG) data of individuals with RTT on both sleep macrostructure and sleep respiratory indexes and compared them to literature normative values. Studies were collected from PubMed, Web of Science, PsycINFO, Ebsco, Scopus, and Cochrane Library till 26 April 2022. Across 13 included studies, the 134 selected RTT cases were mostly females being MECP2 (n = 41) and CDKL5 (n = 4) positive. They were further stratified by gene, age, and clinical features. Findings of comparison with literature normative values suggested shorter total sleep time (TST) and sleep onset latency (SOL), twice as long wake after sleep onset (WASO) with lower sleep efficiency (SEI) in RTT, as well as increased non-rapid eye movement stage 3 (stage N3) and decreased rapid eye movement sleep. Based on limited data per stratifications, we found in RTT cases <5 years old lower stage N3, and in RTT cases >5 years old less WASO and more WASO in the epileptic strata. However, meta-results generated from studies designed with comparison groups only showed lower stage N1 in RTT than in healthy comparison, together with similar SEI and stage N3 to primary snoring subjects. For sleep respiratory indexes, severe disordered sleep breathing was confirmed across roughly all RTT strata. We are the first study to meta-analyze PSG data of subjects with RTT, illustrating shorter TST and aberrant sleep staging in RTT that may vary with age or the presence of epilepsy. Severe nocturnal hypoxemia with apneic events was also demonstrated. More studies are needed to explore and elucidate the pathophysiological mechanisms of these sleep findings in the future.

Physical Activity Among Urban Children with Asthma: Does Sleep Matter?

The present study examined associations between sleep and physical activity among a diverse sample of 97 urban children (ages 7-9) with persistent asthma. Differences in associations were evaluated by race/ethnicity and weight status. The extent to which sleep moderated the association between lung function and physical activity was also evaluated. Generalized linear models were utilized to examine associations. Findings indicated that, among the aggregate sample, more frequent nighttime awakenings were associated with less time spent engaging in moderate-to-vigorous physical activity (MVPA). Important differences in these associations were identified by both race/ethnicity and weight status. Better lung function was associated with, (a) higher levels of MVPA for children with better sleep efficiency and fewer nighttime awakenings, and (b) lower levels of MVPA for children with poorer sleep efficiency and more frequent nighttime awakenings. In short, sleep mattered with respect to children's physical activity levels in this sample.

Changes in Sleep Patterns in Korean Early Adolescents during Sexual Maturation

Purpose: Teenagers’ sleep patterns show physiological delays influenced by sexual maturation and other external time-related factors. However, Korean adolescents show differences in the onset of pubertal development and have shorter sleep durations than other adolescents worldwide. Therefore, we assessed sleep patterns and sexual maturation in Korean early adolescents to evaluate changes in sleep patterns in relation to sexual maturation in early adolescents with sleep deprivation.Methods: From March to August 2017, we surveyed children aged 10 to 12 years in Seongnam (Seongnam Atopy Project). We evaluated items related to sleep and sexual maturation, assessed sleep duration and sleepiness scale scores, and analyzed the relationships of sleep parameters with sex, height, weight, and sexual maturation rating (SMR).Results: In total, 620 children were included. Sleep duration was 8.63±0.81 hours in boys and 8.40±0.98 hours in girls. Sleep started from PM 11:00±AM 0:47 in boys and PM 11:13±AM 1:06 in girls, and ended at AM 7:38±AM 0:27 in boys and AM 7:34±AM 0:27 in girls. After adjusting for sex and standardized body mass index, bedtime was delayed as the SMR increased (mean delay for each rating increase, 0.251 hours; P=0.001; 95% confidence interval [CI], 0.105 to 0.397). SMR did not influence the wake-up time, although sleep duration decreased as the SMR increased (mean decrease for each rating increase, 0.258 hours; P=0.001; 95% CI, –0.403 to –0.114). The sleepiness scale scores showed no relationship with SMR. Conclusion: Sleep patterns, especially sleep duration and bedtimes, show changes with sexual maturation in adolescents, who are vulnerable to sleep deprivation.

Literature Cases Summarized Based on Their Polysomnographic Findings in Rett Syndrome

Rett syndrome (RTT) is a severe and rare neurodevelopmental disorder affecting mostly girls. In RTT, an impaired sleep pattern is a supportive criterion for the diagnosis, yet little is known regarding the sleep structure and sleep respiratory events. Aiming to delineate sleep by aggregating RTT case (series) data from published polysomnographic studies, seventy-four RTT cases were collected from eleven studies up until 6 February 2022 (PROSPERO: CRD 42020198099). We compared the polysomnographic data within RTT stratifications and to a typically developing population. MECP2 cases demonstrated shortened total sleep time (TST) with increased stage N3 and decreased REM sleep. In cases with CDKL5 mutations, TST was longer and they spent more time in stage N1 but less in stage N3 than those cases affected by MECP2 mutations and a typically developing population. Sleep-disordered breathing was confirmed by the abnormal apnea/hypopnea index of 11.92 ± 23.67/h TST in these aggregated cases. No association of sleep structure with chronological age was found. In RTT, the sleep macrostructure of MECP2 versus CDKL5 cases showed differences, particularly regarding sleep stage N3. A severe REM sleep propensity reduction was found. Aberrant sleep cycling, possibly characterized by a poor REM ‘on switch’ and preponderance in slow and high-voltage sleep, is proposed.

Examining adolescents' obesogenic behaviors on structured days: a systematic review and meta-analysis

BACKGROUND

The structured days hypothesis posits that 'structured days' (i.e., days with pre-planned, segmented, and adult-supervised environments) reduce youth obesogenic behaviors. Structured days may be especially important for adolescents', as adolescence (12-19 years) is a period of developmental milestones and increased autonomy. Therefore, the objective of this systematic review and meta-analysis is to evaluate the relationship between structured days and adolescents' obesogenic behaviors (i.e., physical activity, diet, screen time, and/or sleep).

METHODS

From February to April of 2020, four databases (i.e., Embase, PubMed, Web of Science, and PsychINfo) were searched for cross-sectional, longitudinal, and intervention (i.e., baseline data only) studies reporting obesogenic behaviors on more structured versus less structured days (i.e., weekday versus weekend or school year versus summer/holiday).

RESULTS

A total of 42,878 unique titles and abstracts were screened with 2767 full-text articles retrieved. After review of full-text articles, 296 studies were identified (sleep k = 147, physical activity k = 88, screen time k = 81, diet k = 8). Most studies were conducted in North America, Europe & Central Asia, or East Asia & the Pacific used self-report measures and compared school days to weekend days. Meta-analyses indicated that adolescents' physical activity (standardized mean difference [SMD] = -0.25 [95%CI - 0.48, -0.03]) and screen time (SMD = -0.48 [95%CI - 0.66, -0.29]) were less healthy on less structured days. Differences did not reach statistical significance for sleep (SMD = -0.23 [95%CI - 0.48, 0.02]) and diet (SMD = -0.13 [95%CI - 0.77, 0.51]), however, sleep timing (SMD = -1.05 [95%CI - 1.31, -0.79]) and diet quantity (SMD = -0.29 [95%CI - 0.35, -0.23]) were less healthy on less structured days. The review identified studies with large heterogeneity.

CONCLUSIONS

Findings indicate that adolescents' physical activity, screen time, sleep timing, and diet quantity are less healthy on less structured days. Interventions for adolescents to prevent and treat obesity may be more successful if they are designed to target times that are less structured.

Sleep and brain evolution across the human lifespan: A mutual embrace

Sleep can be considered a window to ascertain brain wellness: it dynamically changes with brain maturation and can even indicate the occurrence of concealed pathological processes. Starting from prenatal life, brain and sleep undergo an impressive developmental journey that accompanies human life throughout all its steps. A complex mutual influence rules this fascinating course and cannot be ignored while analysing its evolution. Basic knowledge on the significance and evolution of brain and sleep ontogenesis can improve the clinical understanding of patient's wellbeing in a more holistic perspective. In this review we summarized the main notions on the intermingled relationship between sleep and brain evolutionary processes across human lifespan, with a focus on sleep microstructure dynamics.

Slow Wave Sleep of Elite and Nonelite Gymnasts Is Influenced by Weekly Training Hours, Not by Fitness Level

PURPOSE

This study aimed to determine the influencing factors of potential differences in sleep architecture between elite (EG) and nonelite (NEG) female artistic gymnasts.

METHODS

Twelve EG (15.1 [1.5] y old) and 10 NEG (15.3 [1.8] y old) underwent a nocturnal polysomnography after a regular training day (5.8 [0.8] h vs 2.6 [0.7] h), and, on a separate test day, they performed an incremental treadmill test after a rest day in order to determine physical fitness status. A multiple linear regression assessed the predictive value of training and fitness parameters toward the different sleep phases. Total sleep time and sleep efficiency (proportion of time effectively asleep to time in bed), as well as percentage of nonrapid eye movement sleep phase 1 (NREM1) and 2 (NREM2), slow wave sleep (SWS), and rapid eye movement sleep (REM), during a single night were compared between EG and NEG using an independent-samples t test.

RESULTS

Peak oxygen uptake influenced NREM1 (β = 1.035, P = .033), while amount of weekly training hours predicted SWS (β = 1.897, P = .032). No differences were documented between EG and NEG in total sleep time and sleep efficiency. SWS was higher in EG (36.9% [11.4%]) compared with NEG (25.9% [8.3%], P = .020), compensated by a lower proportion of NREM2 (38.7% [10.2%] vs 48.4% [6.5%], P = .017), without differences in NREM1 and REM.

CONCLUSIONS

The proportion of SWS was only predicted by weekly training hours and not by training hours the day of the polysomnography or physical fitness, while NREM1 was linked with fitness level. Sleep efficiency did not differ between EG and NEG, but in EG, more SWS and less NREM2 were identified.

Relationships between cortical, cardiac, and arousal-motor activities in the genesis of rhythmic masticatory muscle activity across sleep cycles in primary sleep bruxism children

STUDY OBJECTIVES

The present study aimed to clarify the physiological relationships between rhythmic masticatory muscle activity (RMMA) and cyclic changes in cortical, autonomic, and arousal-motor activities during sleep in sleep bruxism (SB) children.

METHODS

Polysomnographic recordings were performed on fifteen SB children (9 boys, 6 girls, 10.3 ± 2.5 years) and eighteen control children (5 boys, 13 girls, 10.7 ± 3.1 years) free from sleep and developmental disorders. Sleep and RMMA were scored by the standard rules. Sleep cycle was divided into NREM and REM sleep segments and the frequency of RMMA, transient arousal and movement, and cortical and cardiac activities were then quantitatively analyzed in relation to sleep cycles.

RESULTS

Neither sleep architecture nor sleep stage distribution of RMMA significantly differed between two groups. In sleep cycles, SB children showed more frequent RMMA in all segments than controls, while cyclic changes in cortical and autonomic activities did not significantly differ between two groups. In SB children, RMMA was the most frequent in the last NREM segment before REM sleep and was associated with increases in cortical beta activity and arousal; more than 70% of RMMA time-dependently occurred with cortical and motor arousals.

CONCLUSIONS

This is the first study to suggest that the potentiation of RMMA occurrence was associated with transient arousal under cyclic sleep processes in primary SB children.

Neurobiology and Neuroprotective Benefits of Sleep

PURPOSE OF REVIEW

This article outlines the neurocircuitry underlying sleep-wake and circadian physiology with a focus on the fundamental roles that sleep and circadian health play in optimal neurologic function.

RECENT FINDINGS

The foundation of sleep and wake promotion is laid primarily by the "fast-acting" neurotransmitters: γ-aminobutyric acid (GABA) for sleep and glutamate for wake. External to these primary systems are a host of modulatory systems that are characterized by two flip-flop switches of mutually inhibitory neurotransmitter systems that facilitate transitions between wake and sleep as well as non-rapid eye movement (non-REM) and REM sleep. Additional mechanisms are in place to help coordinate the sleep-wake states with environmental, metabolic, and behavioral demands. The complexity of the evolutionarily preserved sleep-wake and circadian systems, the proportion of the day dedicated to the natural sleeping period, as well as the neurocognitive dysfunction and neurodegeneration caused by deficient sleep highlight the importance of defining, assessing, and optimizing the sleep health of our patients and ourselves.

SUMMARY

Exciting discoveries continue to elucidate the underlying mechanisms of sleep and wake state coordination, reinforcing fundamental healthy practices and paving the way for new interventions that preserve and promote optimal neurologic health.

Impact of pre-sleep habits on adolescent sleep: an Italian population-based study

OBJECTIVE

Several evidences demonstrate that pre-sleep habits may negatively impact adolescent sleep, yet few data exist on Italian population. This study aimed to investigate the relationship between pre-sleep habits, use of technology/activity and sleep in Italian adolescents.

METHODS

Self-report questionnaires including Italian version of School Sleep Habits Survey and use of technology/activity (eg smartphone, PC) at bedtime were administered to 972 adolescents (13-19 years) from Lombardia. We stratified the sample in five groups according to the age: Group I (13-14 years), Group II (15 years), Group III (16 years), Group IV (17 years), Group V (18-19 years).

RESULTS

Our descriptive analysis reveals a different sleep profile across age-groups: Group III showed highest percentage of bad sleep (26.7%) and frequent nocturnal awakenings (24.1%), Group V had the highest percentage of insufficient sleep (40,4%) and difficulty falling asleep (42.7%) and Group IV presented an elevated difficulty in waking up in the morning (70.1%). A significant negative correlation was found in total group between use of smartphone, internet and studying/doing homework and total sleep time. The use of smartphone, internet videogames, listening to music and studying/doing homework was positively associated with delayed bedtime.

CONCLUSIONS

This study confirms the great impact of pre-sleep habits, and in particular the use of technology on adolescent sleep. Our results demonstrate that sleep is strongly altered among Italian adolescents using electronic devices in evening. The type of technology may be related to specific sleep profile, emphasizing the importance of stratification analyses to identify associated factors to sleep problems.

Severe effects of the COVID-19 confinement on young children's sleep: A longitudinal study identifying risk and protective factors

The COVID-19 confinement has dramatically altered daily routines, causing decreased sleep quality in adults. This necessitates careful observation, as sleep plays a crucial role in brain maturation and poor sleep increases the risk of psychopathology, particularly in the young population. Through an online survey with one baseline (April 2020) and two follow-up assessments (May and June 2020), we examined the effect of confinement on sleep quality in 452 babies (0-35 months) and 412 preschool children (36-71 months) from several, mainly European, countries. An acute decrease in sleep quality was found in both groups of children. However, at follow-up assessments, this effect rebounded to the level reported for the period before the confinement. Importantly, caregiver's stress level was identified as a substantial risk factor determining lower sleep quality in both groups of children across assessments. Protective factors conserving children's sleep quality included caregiver's engagement in mindfulness techniques or childcare, and the presence of siblings and pets. In the near future, we may repeatedly experience the circumstances of abruptly enforced confinement. Our findings reveal promising pathways of action to protect young children's sleep, with which to essentially mitigate the long-term consequences of the pandemic on brain development and mental health.

Sleep-related difficulties in healthy children and adolescents

BACKGROUND

As sleep-related difficulties are a growing public health concern, it is important to gain an overview of the specific difficulty areas of the most vulnerable individuals: children. The current descriptive study presents the prevalence of sleep-related difficulties in two large samples of healthy children and adolescents and outlines the effects of age, gender, and socioeconomic status (SES) on various sleep-related difficulties.

METHODS

Participants were 855 4-9 year-old children (child sample) and 1,047 10-17 year-old adolescents (adolescent sample) participating 2011-2015 in the LIFE Child study, a population-based cohort study in Germany. Parents of the child participants completed the Children's Sleep Habits Questionnaire (CSHQ), whereas adolescents self-administered the Sleep Self Report (SSR). Familial SES was determined by a composite score considering parental education, occupational status, and income. Multiple regression analyses were carried out to address the research question.

RESULTS

Among 4-9 year-old children, the mean bedtime was reported to be 8 p.m., the mean wake-up time 7 a.m., and sleep duration decreased by 14 min/year of age. 22.6 % of the children and 20.0 % of the adolescents showed problematic amounts of sleep-related difficulties. In the child sample, bedtime resistance, sleep onset delay, sleep-related anxiety, night waking, and parasomnia were more frequent in younger than older children. In the adolescent sample, difficulties at bedtime were more frequent among the younger adolescents, whereas daytime sleepiness was more prominent in the older than the younger adolescents. Considering gender differences, sleep-related difficulties were more frequent among boys in the child sample and among girls in the adolescent sample. Lower SES was associated with increased sleep-related difficulties in the adolescent, but not the child sample.

CONCLUSIONS

The present results report sleep-related difficulties throughout both childhood and adolescence. Gender differences can already be observed in early childhood, while effects of SES emerge only later in adolescence. The awareness for this circumstance is of great importance for pediatric clinicians who ought to early identify sleep-related difficulties in particularly vulnerable individuals.

The rhythm of a preterm neonate's life: ultradian oscillations of heart rate, body temperature and sleep cycles

The objectives are to characterize oscillations of physiological functions such as heart rate and body temperature, as well as the sleep cycle from behavioral states in generally stable preterm neonates during the first 5 days of life. Heart rate, body temperature as well as behavioral states were collected during a daily 3-h observation interval in 65 preterm neonates within the first 5 days of life. Participants were born before 32 weeks of gestational age or had a birth weight below 1500 g; neonates with asphyxia, proven sepsis or malformation were excluded. In total 263 observation intervals were available. Heart rate and body temperature were analyzed with mathematical models in the context of non-linear mixed effects modeling, and the sleep cycles were characterized with signal processing methods. The average period length of an oscillation in this preterm neonate population was 159 min for heart rate, 290 min for body temperature, and the average sleep cycle duration was 19 min. Oscillation of physiological functions as well as sleep cycles can be characterized in very preterm neonates within the first few days of life. The observed parameters heart rate, body temperature and sleep are running in a seemingly uncorrelated pace at that stage of development. Knowledge about such oscillations may help to guide nursing and medical care in these neonates as they do not yet follow a circadian rhythm.

Sleep in children and young adults with interstitial and diffuse lung disease

OBJECTIVE

Obstructive sleep apnea (OSA) is common in adult patients with interstitial lung disease (ILD). The aim of the study was to evaluate the prevalence of OSA and sleep quality in children and young adults with children's interstitial and diffuse lung disease (chILD).

METHODS

A polysomnography (PSG) was performed in room air in all consecutive patients followed at a national reference centre between June 2018 and September 2019. Clinical and PSG data were collected.

RESULTS

The PSG data of 20 patients (12 girls, median age 9 (range 0.5-20) years), were analyzed. Seven (35%) patients had pulmonary alveolar proteinosis (PAP), 5 (25%) a disorder of surfactant metabolism, 3 (15%) diffuse pulmonary hemorrhage, 4 (20%) chILD of unknown etiology and one patient had laryngeal and pulmonary sarcoidosis. The median obstructive apnea-hypnea index (OAHI) was normal at 0 events/hour, with a value > 4 events/hour being observed in 2 young adults: an 18-year-old male with PAP and a vital capacity of 27% predicted who had an OAHI of 10.7 events/hour, and a 20-year-old male with laryngeal and pulmonary sarcoidosis who had positional OSA with an OAHI of 19.5 events/hour. The median total sleep time, sleep efficiency, % of wake after sleep onset, and sleep stages were moderately disturbed.

CONCLUSIONS

Moderate or severe OSA was not observed in children <18 years with chILD. Mild or moderate OSA was observed in 2 young adults with PAP and sarcoidosis. As opposed to adults, OSA seems uncommon in children with chILD.

Breathing Patterns and Oxygenation Saturation During Sleep in Children Habitually Living at High Altitude in the Andes: A Systematic Review

BACKGROUND

Human respiratory physiology changes significantly in high altitude settings and these changes are particularly marked during sleep. It is estimated that 170 million people live above 2,500 m in environments where normal sleep parameters differ from those established at sea level or low altitude.

METHODS

We conducted a systematic review of publications reporting sleep studies in healthy children living at high altitude. For this purpose, data from PubMed, EMBASE, SciELO and Epistemomikos bases were retrieved up to August 2021.

RESULTS

Six articles met specified inclusion criteria; all reporting data were from South America involving 245 children (404 sleep studies) in children aged 0.6 months to 18 years, at altitudes between 2,560 to 3,775 m. The main results were: (1) Central apnea index decreased as the age increased. (2) The obstructive apnea/hypopnea index showed a bimodal profile with an increase in young infants up to age of 4 months, decreasing to 15 months of age, and then a second peak in children aged 4 to 9 years of age, dropping in older schoolchildren and adolescents. (3) Periodic breathing in the first months of life is more marked with increasing altitude and decreases with age.

CONCLUSIONS

There are few studies of sleep physiology in children living at high altitude. The international parameters defining normal apnea indices currently used at low altitude cannot be applied to high altitude settings. The interpretation of sleep studies in children living at high altitude is complex because there are important developmental changes across childhood and a wide range of altitude locations. More normative data are required to determine thresholds for respiratory pathology at a variety of high altitude settings.

Current ideas about the roles of rapid eye movement and non-rapid eye movement sleep in brain development

Understanding the links between sleep and brain development is important, as rapid eye movement (REM) sleep and non-REM (NREM) sleep seem to contribute to different aspects of brain maturation. If children have sleep problems, REM sleep and NREM sleep are likely to have different consequences for their developing brain, depending on their age. We highlight important discoveries from human and animal research on the role sleep plays in brain development. A hypothetical model is presented to explain the dynamic relationship of REM sleep and NREM sleep with different processes of brain maturation, with implications for current neonatal care and future research.

Sleep and Memory in Children

Purpose of Review

This short review article aims at emphasizing interesting and important new insights about investigating sleep and memory in children aged between 6 and 13 years (middle childhood).

Recent Findings

That sleep in comparison to wakefulness benefits the consolidation of memories is well established—especially for the adult population. However, the underlying theoretical frameworks trying to explain the benefits of sleep for memory still strive for more substantiate findings including biological and physiological correlates.

Summary

Based on the most recent literature about sleep-related memory consolidation and its physiological markers during middle childhood, this article provides a review and highlights recent updates in this field.

Sleep Architecture in Mechanically Ventilated Pediatric ICU Patients Receiving Goal-Directed, Dexmedetomidine- and Opioid-based Sedation

This single-center prospective observational study aimed to evaluate sleep architecture in mechanically ventilated pediatric intensive care unit (PICU) patients receiving protocolized light sedation. We enrolled 18 children, 6 months to 17 years of age, receiving mechanical ventilation and standard, protocolized sedation for acute respiratory failure, and monitored them with 24 hours of limited (10 channels) polysomnogram (PSG). The PSG was scored by a sleep technician and reviewed by a pediatric sleep medicine physician. Sixteen children had adequate PSG data for sleep stage scoring. All received continuous opioid infusions, 15 (94%) received dexmedetomidine, and 7 (44%) received intermittent benzodiazepines. Total sleep time was above the age-matched normal reference range (median 867 vs. 641 minutes, p = 0.002), attributable to increased stage N1 and N2 sleep. Diurnal variation was absent, with a median of 47% of sleep occurring during night-time hours. Rapid eye movement (REM) sleep was observed as absent in most patients (n = 12, 75%). Sleep was substantially disrupted, with more awakenings per hour than normal for age (median 2.2 vs. 1.1, p = 0.008), resulting in a median average sleep period duration (sleep before awakening) of only 25 minutes (interquartile range [IQR]: 14–36) versus normal 72 minutes (IQR: 65–86, p = 0.001). Higher ketamine and propofol doses were associated with increased sleep disruption. Children receiving targeted, opioid-, and dexmedetomidine-based sedation to facilitate mechanical ventilation for acute respiratory failure have substantial sleep disruption and abnormal sleep architecture, achieving little to no REM sleep. Dexmedetomidine-based sedation does not ensure quality sleep in this population.

Polysomnographic characteristics and sleep-disordered breathing in Schaaf-Yang syndrome

INTRODUCTION

Schaaf-Yang syndrome (SYS) is a genetic disorder caused by truncating variants in the MAGEL2 gene located in the maternally imprinted Prader-Willi syndrome (PWS) region at 15q11-13. The SYS phenotype shares features with PWS, a syndrome with known high incidence of sleep disorders. However, the spectrum of sleep-disorders in SYS has not been described.

METHODS

We performed a retrospective analysis of polysomnograms from 22 patients in an international SYS cohort. Sleep characteristics for individuals with the common c.1996dupC variant (n = 10) were compared to other truncating variants (n = 11).

RESULTS

We collected 33 sleep study reports from 22 patients, ages 2 months - 18.5 years (mean 6.5 years). Mean sleep efficiency was 70.5% (range 45%-93%) with arousal index 14.1/h (1.2-45/h). The mean apnea-hypopnea index (AHI) was 19.1/h (0.9-49/h) with mean obstructive AHI (oAHI) of 16.3/h (0.6-49/h). Mean central apnea index was 2.8/h (0-14/h). Mean oxygen desaturation index was 20.8/h (range 0-85/hr). Obstructive sleep apnea (OSA) was diagnosed in 81%, and 62% had moderate or severe OSA. Elevated central apnea index occurred in 9.5%. Comparison by genotype groups and age did not reveal any difference in OSA findings. Periodic limb movement index (PLMI) was elevated in 4/15 (26%).

CONCLUSION

OSA is frequently identified on polysomnography in patients with SYS. The mean PLMI is elevated compared to normative data. Patients with SYS should have routine polysomnography screening due to high risk of sleep disorders.

Sleep and Limb Movement Characteristics of Children With Atopic Dermatitis Coincidentally Undergoing Clinical Polysomnography

STUDY OBJECTIVES

Atopic dermatitis (AD) is a prevalent, chronic, itchy skin condition. Children undergoing polysomnography (PSG) may coincidentally have AD. Many children with AD have sleep disturbances. Our study aimed to characterize limb movements in children with AD and their effect on sleep.

METHODS

A retrospective chart review was conducted for children who underwent comprehensive attended PSG and had AD. PSG sleep parameters were compared to published normative data. A subset of patients with markedly elevated total limb movements was further compared to a matched group of patients with a diagnosis of periodic limb movement disorder (PLMD) and no history of AD.

RESULTS

There were 34 children with AD 6.36 ± 3.21 years (mean ± standard deviation), 50% female and with mild to moderate AD. There was increased wake after sleep onset (WASO = 46.0 ± 37.8 minutes), sleep onset latency (46.5 ± 53.0 minutes) and total limb movement index (13.9 ± 7.5 events/h) compared to normative values. Although our cohort was mostly mild AD, 7 of the 34 children with AD (20%) had a total limb movement index during sleep > 15 events/h. Increased total limb movements in PLMD versus patients with AD was most notable during stage N2 sleep (38 ± 17 versus 22 ± 7, P = .01, respectively).

CONCLUSIONS

We found altered PSG parameters in children with AD, suggesting that clinicians should consider the diagnosis when affected children undergo PSG. Although our AD cohort was mild, we still determined a need to consider AD when diagnosing PLMD given the presence of elevated total limb movements in children with AD.

CITATION

Treister AD, Stefek H, Grimaldi D, Rupani N, Zee P, Yob J, Sheldon S, Fishbein AB. Sleep and limb movement characteristics of children with atopic dermatitis coincidentally undergoing clinical polysomnography. J Clin Sleep Med. 2019;15(8):1107-1113.

Toward a Better Understanding of the Reciprocal Relations Between Adolescent Psychological Need Experiences and Sleep

In two diary studies, we examined the reciprocal daily association between the satisfaction and frustration of adolescents’ basic psychological needs and sleep, and the role of stress and fatigue in these associations. In Study 1 ( N = 211; 52% female; Mage = 15.86 years, SD = 1.18 years), daily need experiences were unrelated to daily fluctuations in subjective sleep outcomes. However, shorter daily sleep quantity was related to higher daily fatigue, which in turn related to more daily need frustration and less need satisfaction. Study 2 ( N = 51; 49% female; Mage = 15.88 years, SD = 2.88 years) extended these findings by demonstrating that daily need frustration related to shorter objective sleep quantity and longer wake after sleep onset, indirectly through higher symptoms of stress. Poor sleep quality also related to worse need experiences via higher daily fatigue. These findings underscore the dynamic interplay between daily need experiences and adolescent sleep.

How to interpret polysomnography

A 5-year-old child presents to a paediatric clinic with their parents because of concerns about snoring, which is loud, every night and associated with respiratory pauses. This has been present for 6 months. Can clinical evaluation diagnose sleep-disordered breathing in children or are further investigations required? Should further investigations include oximetry or polysomnography? If a polysomnogram is performed, how are the results interpreted? In this paper we describe the indications for polysomnography, outline the parameters measured and decode a clinical polysomnography report.

Anti-Hypothalamus and Anti-Pituitary Auto-antibodies in ROHHAD Syndrome: Additional Evidence Supporting an Autoimmune Etiopathogenesis

BACKGROUND

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD) is a very rare and complex pediatric syndrome characterized by altered hypothalamic thermal regulation, pain threshold, and respiratory control, hyperphagia with rapid weight gain and, often, hypothalamic-pituitary dysfunction. Its etiopathogenesis remains undetermined. We investigated the presence of alterations to target genes and hypothalamic-pituitary autoimmunity in a patient with -ROHHAD syndrome.

METHODS

A 3-year-old girl presenting with obesity after rapid weight gain was diagnosed with ROHHAD syndrome based on clinical features and abnormal biochemical and functional testing results. Because of worsening of rapid symptoms and demonstration of oligoclonal bands on cerebrospinal fluid (CSF) analysis, she was treated with plasmapheresis, methylprednisolone, anti-CD20 monoclonal antibodies, and azathioprine. Despite initial partial clinical improvement, the patient soon died of cardiorespiratory arrest. Post-mortem, whole exome sequencing, high-resolution comparative genomic hybridization array, and optimized indirect immunofluorescence (IIF) analysis were performed on blood and CSF.

RESULTS

No putative causative genomic variants compatible with dominant or recessive inheritance nor clinically significant structural rearrangement were detected. IIF on serum and CSF demonstrated the presence of anti-pituitary and anti-hypothalamus autoantibodies.

CONCLUSIONS

These findings support the involvement of autoimmunity in ROHHAD syndrome. However, response to immunosuppressive treatment was only transient and the patient died. Further cases are required to define the complex disease pathogenesis.

Sleep architecture and homeostasis in children with epilepsy: a neurodevelopmental perspective

Although the influence of sleep on epilepsy has long been recognized, this relationship has yet to be fully exploited to benefit patients. The past decade has seen significant advances in understanding paediatric sleep, providing a framework by which to properly evaluate the sleep of children with epilepsy, which itself has been subject to increasing scrutiny. The role of sleep in learning and the potential for interictal discharges to disrupt sleep-related memory consolidation provide a novel perspective for understanding the association of childhood epilepsy with a high rate of intellectual disability. In this review, I outline the evolution of sleep duration, architecture, and homeostasis across childhood, relating this to the development of cognitive functions. I describe how these may be disrupted or preserved in children with epilepsy; in particular, collating data from polysomnography. Finally, I explore how sleep may, in the future, be modulated to improve cognitive outcome in these patients. WHAT THIS PAPER ADDS: Children with epilepsy have less rapid eye movement sleep than controls, but this improves with seizure cessation. Deep or slow-wave sleep is highly conserved in children with epilepsy. Sleep homeostasis may be disrupted either at a local or global level by the presence of interictal epileptiform discharges.

Sleep-disordered breathing and comorbidities: role of the upper airway and craniofacial skeleton

Obstructive sleep-disordered breathing (SDB), which includes primary snoring through to obstructive sleep apnea syndrome (OSAS), may cause compromise of respiratory gas exchange during sleep, related to transient upper airway narrowing disrupting ventilation, and causing oxyhemoglobin desaturation and poor sleep quality. SDB is common in chronic disorders and has significant implications for health. With prevalence rates globally increasing, this condition is causing a substantial burden on health care costs. Certain populations, including people with sickle cell disease (SCD), exhibit a greater prevalence of OSAS. A review of the literature provides the available normal polysomnography and oximetry data for reference and documents the structural upper airway differences between those with and without OSAS, as well as between ethnicities and disease states. There may be differences in craniofacial development due to atypical growth trajectories or extramedullary hematopoiesis in anemias such as SCD. Studies involving MRI of the upper airway illustrated that OSAS populations tend to have a greater amount of lymphoid tissue, smaller airways, and smaller lower facial skeletons from measurements of the mandible and linear mental spine to clivus. Understanding the potential relationship between these anatomical landmarks and OSAS could help to stratify treatments, guiding choice towards those which most effectively resolve the obstruction. OSAS is relatively common in SCD populations, with hypoxia as a key manifestation, and sequelae including increased risk of stroke. Combatting any structural defects with appropriate interventions could reduce hypoxic exposure and consequently reduce the risk of comorbidities in those with SDB, warranting early treatment interventions.

Across-night dynamics in traveling sleep slow waves throughout childhood

Study Objectives

Sleep slow waves behave like traveling waves and are thus a marker for brain connectivity. Across a night of sleep in adults, wave propagation is scaled down, becoming more local. Yet, it is unknown whether slow wave propagation undergoes similar across-night dynamics in childhood-a period of extensive cortical rewiring.

Methods

High-density electroencephalography (EEG; 128 channels) was recorded during sleep in three groups of healthy children: 2.0-4.9 years (n = 11), 5.0-8.9 years (n = 9) and 9.0-16.9 years (n = 9). Slow wave propagation speed, distance, and cortical involvement were quantified. To characterize across-night dynamics, the 20% most pronounced (highest amplitude) slow waves were subdivided into five time-based quintiles.

Results

We found indications that slow wave propagation distance decreased across a night of sleep. We observed an interesting interaction of across-night slow wave propagation dynamics with age (p < 0.05). When comparing the first and last quintiles, there was a trend level difference between age groups: 2- to 4.9-year-old children showed an 11.9% across-night decrease in slow wave propagation distance, which was not observed in the older two age groups. Regardless of age, cortical involvement decreased by 10.4%-23.7% across a night of sleep. No across-night changes were observed in slow wave speed.

Conclusions

Findings provide evidence that signatures of brain connectivity undergo across-night dynamics specific to maturational periods. These results suggest that across-night dynamics in slow wave propagation distance reflect heightened plasticity in underlying cerebral networks specific to developmental periods.

Effects of long-term non-invasive ventilation on sleep structure in children with Spinal Muscular Atrophy type 2

OBJECTIVE

Changes of sleep architecture have been reported in children with Spinal Muscular Atrophy type 2 (SMA2), mainly represented by a decrease of arousability. No studies have evaluated the effect of long-term ventilation on sleep parameters in these children. The aim of this study was to evaluate the effects of long-term non-invasive positive pressure ventilation (LTNPPV) on sleep architecture and to assess the residual differences from normal controls.

METHODS

Nine consecutive children with SMA2 underwent two distinct polysomnographic (PSG) studies, one in spontaneous breathing, and subsequently after LTNPPV. The results were then compared to 15 age-matched controls.

RESULTS

SMA2 patients showed only slightly modified sleep architecture on LTNPPV: increased stage N2% and decreased number of awakenings, while several significant differences persisted between SMA2 patients on LTNPPV and controls (decreased total sleep time, number of awakenings, sleep efficiency, and percentage of REM sleep). Sleep microstructure, evaluated by means of the Cyclic alternating pattern (CAP) showed only marginal changes on LTNPPV (small shortening of CAP A1 subtype duration and small increase in CAP A3 index). Conversely, CAP parameters on LTNPPV showed significant differences between SMA2 patients vs. controls, with increased A1 subtype percentage and decreased percentage of A2 and A3 subtypes.

CONCLUSIONS

This is the first study in children affected by SMA2 reporting data on sleep microstructure and their changes after LTNPPV. We found persisting, small but important changes in sleep microstructure during LTNPPV in these children, suggesting that this treatment only partially improves their arousability.

Polysomnographic characteristics of adolescents with asthma and low risk for sleep-disordered breathing

PURPOSE

The aim of this study was to describe the polysomnographic characteristics of adolescents with asthma who are at low risk for sleep-disordered breathing (SDB) based on the Pediatric Sleep Questionnaire (PSQ).

METHODS

Overnight polysomnography was performed on 85 adolescents with asthma and a score < 0.33 on the PSQ. The Asthma Control Questionnaire was used to define "well-controlled" versus "inadequately controlled" asthma.

RESULTS

Mean age of participants was 14.5 ± 1.6 years (range, 11 to 17 years), 63.5% were girls, 57.6% were Caucasians, and the mean body mass index percentile was 65.1 ± 26.5. Asthma was well-controlled in 51.7% of the adolescents and inadequately controlled in 15.3%. Mean sleep efficiency (SE) was 88.0 ± 11.1%, and 24.7% had SE < 85%. Mean wakefulness after sleep onset (WASO) was 40.9 ± 44.0 min, and the mean arousal index was 10.8 ± 5.6 per hour. The mean apnea/hypopnea index (AHI) was 2.3 ± 4.2, and 29.4% of participants had SDB (defined by an AHI ≥ 2). Compared with normative values, adolescents with asthma had more nocturnal awakenings and WASO, and less REM sleep. SDB risk was higher in boys [odds ratio = 4.6 (confidence interval 1.4-14.7), p = 0.01]. Asthma control did not impact sleep and respiratory parameters, with no differences found between youth with well-controlled and inadequately controlled asthma.

CONCLUSIONS

Adolescents with asthma are at increased risk of sleep-disordered breathing and suffer from disturbances in sleep continuity with more arousals and sleep fragmentation. Study results highlight the importance of proper screening for sleep-disordered breathing in adolescents with asthma.

Polysomnographic findings in Rett syndrome

INTRODUCTION

Rett syndrome (RS) is a severe neurodevelopment disorder associated with abnormal breathing during wakefulness and disturbed nocturnal behaviour. Breathing abnormalities during daytime have been extensively reported but polysomnographic (PSG) findings have been poorly studied.

MATERIALS AND METHODS

Consecutive patients with RS carrying distinct mutations in MECP2 gene, who underwent a PSG between October 2014 and January 2018, were included in the study. Clinical and PSG data were collected.

RESULTS

Seventeen RS girls, mean age 9.5 ± 2.8 years, were included in the study. Mean total sleep time was 366 ± 102 min. Mean sleep efficiency was reduced (66 ± 19%) with only 3 girls presenting a sleep efficiency above 80%. Wake after sleep onset was increased (33 ± 20%) with an arousal index of 7 ± 6 events/hour. Sleep stages were altered with a normal N1 (2 ± 3%), a decreased N2 (34 ± 20%), an increase of N3 (51 ± 23%) and a decrease of REM sleep (12 ± 9%). Mean apnea hypopnea index (AHI) was increased at 19 ± 37 events/hour, with a predominance of obstructive events. Thirteen patients had an AHI > 1.5 event/hour. Four patients had an obstructive AHI >10 events/hour with one patient having associated tonsillar hypertrophy. Two patients had predominant severe central apneas (central AHI 53 and 132 events/hour) which resolved with noninvasive ventilation and nocturnal oxygen therapy respectively.

CONCLUSION

Girls with RS have poor sleep quality with alterations in slow wave and REM sleep stages. Obstructive respiratory events are uncommon in patients without adenotonsillar hypertrophy. Central respiratory events are rare. Longitudinal studies should help understanding the natural history of sleep disturbances in RS and their relationship with the neurocognitive decline.

Inflammation and asthma control in children with comorbid obstructive sleep apnea

OBJECTIVES

A bi-directional relationship exists between asthma and obstructive sleep apnea (OSA) in which presence of one is associated with increased prevalence and severity of the other. Our objective was to determine whether OSA accounted for differences in airway and systemic inflammation in asthmatic children and whether inflammation was associated with asthma control. We hypothesized that greater severity of SDB would correlate with increased upper airway and systemic inflammation and result in reduced asthma control.

METHODS

Non-obese children aged 4-12 years with persistent asthma, with or without OSA were recruited. Asthma control was measured with the Childhood Asthma Control Test. Children underwent polysomnography and blood sampling, and children with OSA underwent clinically indicated adenotonsillectomy. Tonsils and sera were analyzed for 11 cytokines.

RESULTS

Twenty-seven children (20 with OSA, seven without OSA) participated, mean age 7.9 years, 55.6% female, 92.6% African American. Levels did not differ for any cytokine between children with and without OSA. Lower nadir oxygen saturation was associated with higher levels of tonsil TNF-α (P < 0.001) and IL-10 (P < 0.05). Higher REM-related apnea-hypopnea index was associated with higher levels of tonsil TNF-α (P < 0.05). Children with uncontrolled asthma had significantly higher levels of serum IL-10, IL-13, and TNF-α, and tonsil TNF-α (all P < 0.05) than well-controlled asthmatic children. There was no association between OSA, or any polysomnography variable, and asthma control.

CONCLUSIONS

Despite the presence of OSA-associated airway inflammation, and asthma control-associated airway and systemic inflammation, OSA was not related to level of asthma control in this non-obese, largely minority, low income sample.

[Sleep and cognition in children and adolescents]

Sleep and cognition in children and adolescents Abstract. In this review, one of the most important functions of sleep was described: Its role in promoting cognitive processes in children and adolescents. Particularly, studies of older children and adolescents revealed that sleep interacts in a complex manner with cognitive performance. Moreover, it was shown that sleep supports long-term memory even in young children. This is true for many different long-term memory systems such as memory of factual information (declarative memory), language acquisition, and for reward-related learning, but less so for learning motor skills. Clinical implications arise from observing the consequences of sleep deficits in children and adolescents due to early school hours or due to clinical conditions like attention deficits hyperactive disorder (ADHD), sleep apnea syndrome or other sleep disturbances. Current research has only partially shown that the treatment of sleep problems also benefits cognitive and memory performance. Filling this gap remains an opportunity for further research.