Search

Objectives: Poor sleep is frequently reported in children with neuromuscular diseases (NMD) and cerebral palsy (CP) however breathing disorders during sleep are often the clinical focus. Periodic limb movements (PLMs) have an increased prevalence in adults with NMD and may contribute to sleep disturbance in this population. We assessed the prevalence of PLMs in children with NMD or CP., Methods: Retrospective review of polysomnography (PSG) with leg electromyography in children age 1-18 years with NMD (including Duchenne muscular dystrophy, myotonic dystrophy, spinal muscular atrophy) or CP performed at a paediatric sleep centre 2004-2022., Results: Leg electromyography was available in at least 1 PSG in 239 children (125 NMD, 114 CP), and in 2 PSGs in 105 children (73 NMD, 32 CP). At initial PSG, 72 (30 %) were female with a median age 9y and respiratory disturbance index 3.5/h (interquartile range 1.3-9.9/h). Elevated PLM index (PLMI; >5/h) occurred in 9.6 % of each of the CP and NMD groups, quantified by initial PSG. Overall, PLMI increased from baseline (median 0, maximum 33/h) to follow-up (median 0, maximum 55.8/h; p < 0.05). In those with an elevated PLMI, arousal percentage attributable to PLMs was up to 25 % (median 7.5 %)., Conclusions: Elevated PLMI occurred at a higher prevalence in children with NMD and CP than reported in other clinic-referred paediatric populations. It is important that PLMs are not overlooked as identification and treatment may help improve sleep outcomes. Further research is required to understand the pathophysiology and consequences of PLMs specifically in this population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Children with Down syndrome (DS) have a high prevalence of sleep disordered breathing (SDB) and altered cardiovascular autonomic control. We aimed to analyze the effect of DS on the surge in heart rate (HR) and pulse transit time (PTT, an inverse surrogate measure of blood pressure change) at respiratory event termination., Methods: 44 children (3-19 y) with DS and 44 typically developing (TD) children matched for SDB severity, age and sex underwent overnight polysomnography. Multilevel modelling determined the effect of DS on HR and PTT changes between a 10s pre-event to the latter half of each respiratory event (late-event) and 15s post-event during NREM and REM, accounting for SDB severity and event length., Results: The children with DS had a significantly smaller % change in HR late-event to post-event (NREM: DS 26.4 % ± 17.5 % (mean ± SD), TD 30.7 % ± 21.0 %; REM DS 16.9 % ± 15.3 %, TD 21.0 % ± 14.0 %; p < 0.05 for both) compared with TD children for obstructive events, and central events (13.2 % ± 17.0 %, TD 18.8 % ± 17.0 %; p < 0.01) during REM. %change in PTT was significantly smaller in the DS group during NREM and REM from pre-event and late-event to post-event compared with TD children for obstructive and central events., Conclusion: These results suggest children with DS have dampened HR and BP responses to respiratory events compared with TD children. Whether this is symptomatic of autonomic dysfunction or a protective factor for the cardiovascular system in children with DS remains to be elucidated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Sleep disorders, particularly sleep disordered breathing (SDB), are common in children with Down syndrome (DS). We investigated the relationship between SDB severity and parental psychological wellbeing and their perception of social support., Methods: 44 children with DS (3-19 years) underwent overnight polysomnography and were categorised into three groups: primary snoring, Mild and Moderate/Severe obstructive sleep apnoea (OSA). Parents completed questionnaires about their child's behaviour (Child Behavior Checklist), sleep symptoms (Pediatric Sleep Survey Instrument) and SDB-related quality of life (OSA-18), together with the DUKE-UNC Functional Social Support (DUKE) and Psychological General Well-Being Index (PGWBI) questionnaires for themselves. 34 children completed a follow-up study after 2 years., Results: There were no significant differences between SDB severity groups for parental perceived social support or psychological wellbeing. Total scores on the DUKE were below average and PGWBI scores were indicative of moderate psychological distress in all three groups. Reduced perceived levels of social support were significantly correlated with externalising child behaviour and sleep disturbance. Diminished parental psychological wellbeing was also significantly correlated with increased sleep disturbances and reduced quality of life in children. At follow-up there were no significant changes in any questionnaire outcome, however parents of children with improved SDB severity had improved PGWBI vitality scores., Conclusion: The degree of parent-reported sleep disturbance in children with DS was linked to suboptimal perceived parental social support and poor psychological wellbeing. Our results emphasise the need for enhanced awareness of the detrimental effects of sleep problems in children with DS on parental wellbeing., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: The gold standard investigation for central disorders of hypersomnolence is the Multiple Sleep Latency Test (MSLT). As the clinical features of these disorders of hypersomnolence evolve with time in children, clinicians may consider repeating a previously non-diagnostic MSLT. Currently there are no guidelines available regards the utility and timing of repeating paediatric MSLTs., Methods: Retrospective review of children aged 3-18years with ≥2MSLTs between 2005 and 2022. Narcolepsy was defined as mean sleep latency (MSL) <8min with ≥2 sleep onset REM (SOREM); idiopathic hypersomnia (IH) was defined as MSL <8min with <2 SOREM. MSLTs not meeting these criteria were labelled non-diagnostic., Results: 19 children (9 female) with initial non-diagnostic MSLT underwent repeat MSLT, with 6 proceeding to a 3rd MSLT following 2 non-diagnostic MSLTs. The 2nd MSLT resulted in diagnosis in 6/19 (32 %) (3 narcolepsy, 3 IH); and 2/6 (33 %) 3rd MSLT were diagnostic (2 IH). Median age at initial MSLT was 7.5y (range 3.4-17.8y), with repeat performed after median of 2.9y (range 0.9-8.2y), and 3rd after a further 1.9 years (range 1.2-4.2y). Mean change in MSL on repeat testing was -2min (range -15.5min to +4.9min, p = 0.18). Of the 8 diagnostic repeat MSLTs, in addition to the MSL falling below 8 min, 2 children also developed ≥2 SOREM that had not been previously present., Conclusions: A third of repeat MSLTs became diagnostic, suggesting repeat MSLT should be considered in childhood if clinical suspicion persists. Further work needs to address the ideal interval between MSLTs and diagnostic cut-points specific to the paediatric population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Excessive daytime sleepiness (EDS) is common in childhood and is currently quantified using adult criteria on a multiple sleep latency test (MSLT). This study aimed to describe paediatric MSLT results, particularly focussing on a previously proposed alternative mean sleep latency (MSL) threshold for children of 12 min, and assess the impact of a 5th nap. We performed a retrospective analysis of MSLTs at a single paediatric centre from 2004 to 2021. Narcolepsy was defined as a mean sleep latency (MSL) ≤8min with ≥2 sleep onset REM (SOREM) periods. Idiopathic Hypersomnia (IH) was defined as a MSL ≤8min with <2 SOREMs. An ambiguous MSLT result was defined as a MSL 8-12min and/or ≥2 SOREM periods. Of 214 MSLTs [50 % female, median age 14.0y (range 3.3-20.1y)], narcolepsy was diagnosed in 48 (22 %), IH in 22 (10 %) and the result was ambiguous in 44 (21 %). Those with ambiguous MSLT results were older (15.6 vs 13.4y, p = 0.006) with a higher proportion of females (61 % vs 35 %, p = 0.01) in comparison to the narcolepsy group. A 5th nap was performed in 60 (28 %) of MSLTs and only changed the outcome in one case. In conclusion, MSLT results are borderline in 21 % of paediatric cases, suggesting that current adult diagnostic criteria may miss narcolepsy and IH in children. A 5th nap usually makes no difference or increases the MSL, suggesting that a four nap MSLT protocol could be used apart from rare cases where the result is borderline after the 4th nap., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: This study compared measurements of sleep and wake assessed with actigraphy, sleep diary and polysomnography in children with Down syndrome (DS) and also compared measures of actigraphic sleep recording in children with DS and typically developing (TD) children., Methods: Children with DS aged 3-19 years (N = 44) referred for assessment of sleep disordered breathing (SDB) underwent overnight polysomnography, together with 1 week of actigraphy with sleep diary. Actigraphy data from the children with DS were compared with data collected from TD children, matched for age and sex., Results: 22 children (50%) with DS completed >3 consecutive nights of actigraphy with a matched sleep diary. There were no differences between bedtimes, wake times or time in bed on weeknights, weekends or over 7 nights between actigraphy and sleep diary. Total sleep time was over estimated by the sleep diary by almost 2 h and the number of night awakenings under-reported. Compared to matched TD children (N = 22), there was no difference in total sleep time, however children with DS fell asleep more quickly (p < 0.001), had more awakenings (p = 0.001) and more time awake after sleep onset (p = 0.007). Children with DS exhibited less variability in both bedtimes and wake times, and fewer had >1 h sleep schedule variability., Conclusions: Parental sleep diaries over-estimate total sleep time but accurately report bed and wake times compared to actigraphy in children with DS. Children with DS have more regular sleep patterns than TD children of the same age, which is important for optimising daytime functioning. The reasons behind this warrant further investigation., Competing Interests: Declaration of competing interest Authors declare conflict of interest none., (Crown Copyright © 2023. Published by Elsevier B.V. All rights reserved.)

Background: Resolution of sleep disordered breathing (SDB) in typically developing children normalises heart rate variability (HRV), a measure of autonomic control, to that of non-snoring controls. Children with Down Syndrome (DS) have dampened heart rate variability (HRV) but the effect of treatment is not known. To assess the effect of improvement of SDB on autonomic control we compared HRV in children with DS whose SDB improved over 2 y, to those whose SDB did not improve., Methods: 24 children (3-19 y) had a baseline and follow-up polysomnographic study 2 y later. Improved SDB was defined as a reduction in obstructive apnea hypopnea index (OAHI) to ≤ 50% of baseline. Children were grouped into Improved (n = 12) and Unimproved (n = 12). Power spectral analysis of the ECG determined low frequency (LF), high frequency (HF) power and the LF/HF ratio. Seven children in the Improved and 2 in the Unimproved group were treated following the baseline study., Results: In the Unimproved group at follow-up, LF power was lower compared to baseline during N3 and Total Sleep (p < 0.05 for both). HF power was lower during REM (p < 0.05). HRV remained unchanged between studies in the Improved group., Conclusion: Autonomic control worsened as indicated by lower LF and HF power in children whose SDB was not improved. In contrast, in those children with improved SDB, autonomic control remained the same, suggesting improvement in SDB severity prevents further worsening of autonomic control in children with DS., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Repetitive surges in heart rate (HR) at respiratory event termination underpin the altered autonomic HR control associated with sleep disordered breathing (SDB). As children born preterm are at greater risk of adverse cardiovascular outcomes, we aimed to determine whether the HR response to obstructive respiratory events was elevated compared to term-born children., Methods: Fifty children (3-12 years) born preterm, were matched for SDB severity, age and gender with term born children. Multilevel modelling determined the effect of preterm birth and arousal on HR changes between a 10s baseline to the latter half of respiratory events and 15s post event during NREM and REM., Results: 1203 events were analysed (NREM: term 380; preterm 383; REM: term 207; preterm 233). During NREM fewer events terminated in arousal in the preterm compared with term group (preterm 68%; term 84%; χ 2  = 27.2, p < 0.001). There were no differences in REM. During NREM, HR was lower in the preterm group at all event phases, with and without associated arousals (P < 0.01 for all). % change in HR from baseline to post event was higher in the preterm compared with term group (preterm: median 23% IQR (12%,34%); term: 18% (10%,29%); p < 0.01) and late event to post event (preterm: 30% (21%, 32%); term 28% (20%,39%); p < 0.01) in events associated with arousals., Conclusion: The greater magnitude of surges in HR following respiratory events terminating with arousal in preterm born children, although small, occur repeatedly throughout the night and may contribute to adverse cardiovascular outcomes, although further studies are required., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Study Objectives: Obstructive sleep disordered breathing (SDB), has adverse neurocognitive and behavioral sequelae in children, despite conventional measures of sleep disruption being unaffected. There is growing evidence that sleep spindles may serve as a more sensitive marker of sleep quality. We investigated the relationship between sleep spindles and sleep fragmentation and neurocognition across the spectrum of SDB severity in children., Methods: Children 3-12 years old referred for clinical assessment of SDB and age matched control children from the community were recruited and underwent polysomnography. Sleep spindles were identified manually during N2 and N3 sleep. Spindle activity was characterised as spindle number, density (number of spindles/h) and intensity (spindle density x average spindle duration). Children completed a battery of tests assessing global intellectual ability, language, attention, visuospatial ability, sensorimotor skills, adaptive behaviors and skills and problem behaviors and emotional difficulties., Results: Children were grouped into control, Primary Snoring, Mild OSA and Moderate/severe OSA, N = 10/group. All measures of spindle activity were lower in the SDB groups compared to the Control children and this reached statistical significance for Mild OSA (p < 0.05 for all). Higher spindle indices were associated with better performance on executive function and visual ability assessments but poorer performance on auditory attention and communication skills. Higher spindle indices were associated with better behavior., Conclusion: The reduced spindle activity observed in the children with SDB, particularly Mild OSA, indicates that sleep micro-architecture is disrupted and that this disruption may underpin the negative effects of SDB on attention, learning and memory., (Crown Copyright © 2022. Published by Elsevier B.V. All rights reserved.)

Objectives: Adherence to Continuous Positive Airway Pressure (CPAP) in children can be challenging. Advancements in CPAP technology have potential to influence adherence. The aim of this study was to compare adherence rates of children with obstructive sleep apnoea (OSA) initiated on autotitrating CPAP (APAP) with remote modem monitoring compared to a cohort started on fixed pressure CPAP alone., Methods: Children aged over 3 years starting APAP at our centre between February 2017 and February 2020 were included. Therapy data was obtained for the initial 90 days. Data was compared to a cohort of children started on CPAP between July 2004 and September 2008., Results: A total of 61 patients with a median age of 14.3 years formed the APAP group, and were significantly older than the CPAP group who had a median age of 8.6 years (p = 0.02). Co-morbid conditions were present in 51% compared with 69% in the earlier cohort (p = 0.11). No significant difference was found in any adherence parameters between the groups. The value closest to achieving a significant difference was hours used per day used, with an median of 5.2 h in the CPAP group compared with 7.0 h in the APAP group (p = 0.07). Two-way ANOVA including age group (above or below 13 years) showed that both age group and treatment group (CPAP vs APAP) were significantly associated with a difference in adherence (F = 4.41, p = 0.006), with mean hours used on days used being highest in the APAP group aged under 13 years. However no significant interaction was found between age and treatment group., Conclusion: Despite the convenience for patients with outpatient initiation and ability to achieve optimal pressures quickly and remotely, our results show no improvement in adherence using APAP with remote monitoring, with the possible exception of children aged under 13 years. A large randomized controlled trial would be required to confirm these findings., (Copyright © 2021. Published by Elsevier B.V.)

Objectives: Children with Down syndrome (DS) are recommended to undergo polysomnography (PSG) by the age of four years due to the high prevalence of obstructive sleep apnea (OSA) in this group, but compliance is incomplete. To further understand referral patterns for PSG in this condition, we aimed to compare demographics, PSG results, OSA severity, behavior, daytime functioning and quality of life (QOL) between children with DS referred for sleep testing and those recruited from the community., Study Design: Children 3-19 years with DS was included: 20 referred clinically for assessment of OSA and 24 volunteers from the community. Demographic and anthropometric data, PSG parameters, sleep-related symptoms and QOL, behavior and daytime functioning were compared between groups., Results: OSA severity did not differ between groups: 50% of the clinical and 42% of the community group had moderate/severe OSA. The clinical group had a higher weight z-score, BMI z-score, waist and hip circumference and neck-to-waist ratio. Questionnaire scores for daytime functioning, behavior and QOL were not different between groups., Conclusions: Despite not being referred for clinical sleep assessment, 42% of children with DS recruited from the community had moderate/severe OSA. There was no difference in the QOL, behavior, daytime functioning and sleep symptoms questionnaires although the clinical group had a higher BMI-Z score and overt signs of obesity. These findings underscore the importance of PSG screening of all children with DS., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Children with Down syndrome (DS) are at increased risk for sleep disordered breathing (SDB), which can have adverse effects on the cardiovascular system. In adults with SDB, nocturnal dipping of heart rate (HR) and blood pressure (BP) is reduced, and this is associated with an increased risk of future cardiovascular events. We aimed to compare nocturnal dipping of HR and pulse transit time (PTT) (a surrogate inverse measure of BP change) in children with DS and SDB to those of typically developing (TD) children with and without SDB., Methods: 19 children with DS (3-18 years) were age and sex matched with 19 TD children without SDB (TD-) and with 19 TD children with matched severity of SDB (TD+). Nocturnal dipping was assessed as the percentage change in HR and PTT from wake before sleep onset to total sleep, N2, N3 and REM sleep across the night and to the first cycle of sleep., Results: Children with DS exhibited reduced nocturnal dipping of HR during total sleep, N2, N3 and REM sleep and increased PTT (reduced BP dipping) in N2 sleep. Fewer children with DS exhibited a greater than 10% fall in HR between wake and N2 or REM sleep compared to TD+ children., Conclusions: Our findings demonstrate significantly reduced nocturnal dipping of HR in children with DS compared to TD children matched for SDB severity, suggesting SDB has a greater cardiovascular effect in these children. Further studies are required to fully understand the mechanisms involved and to assess if treatment of SDB improves nocturnal dipping., (Crown Copyright © 2021. Published by Elsevier B.V. All rights reserved.)

Aims: To review the contributions of Australian and New Zealand research on adenotonsillectomy for the treatment of symptoms of obstructed breathing during sleep (sleep disordered breathing, SDB) in children., Methods: A search of the scientific literature was conducted using the MEDLINE (Ovid), PubMed and Scopus databases in August 2020. The following search string was used: (tonsillectomy OR adenoidectomy OR adenotonsillectomy) AND (paediatric OR child) AND (Australia OR New Zealand). A focused internet search was additionally conducted on Google to identify grey literature., Results: Researchers from Australia and New Zealand have made important contributions to the understanding and improvement of adenotonsillectomy (AT), including its epidemiology, cost, surgical techniques and peri-operative safety. Rates of AT have fluctuated over the years, becoming the most common paediatric surgery today, with SDB becoming the most common indication. Research in Australia and New Zealand has also focussed on the impact of AT on quality of life, and behaviour, neurocognition and cardiovascular sequelae., Conclusions: Australian and New Zealand researchers have played a significant role in understanding the epidemiology and improving the safety of AT. There are promising directions in research still to come, including better understanding of the reasons for geographical variation in surgery rates, developing more efficient pre-operative risk assessment tools and alternative treatment options for mild OSA., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: To investigate the role of ventilatory control instability (i.e. loop gain) in children with Down syndrome and sleep disordered breathing., Methods: Children (3-19 years) with Down syndrome and sleep disordered breathing (n = 14) were compared with typically developing children (n = 14) matched for age, sex and sleep disordered breathing severity. All children underwent overnight polysomnography. Spontaneous sighs were identified and a 180s analysis window (60s pre-sigh to 120s post-sigh) containing flow measurements and oxygen saturation were created. Loop gain, a measure of the sensitivity of the negative feedback loop that controls ventilation, was estimated by fitting a mathematical model of ventilatory control to the post-sigh ventilatory pattern. Results; Loop gain was significantly higher in children with Down syndrome compared to matched typically developing children (median loop gain [interquartile range]: 0.36 [0.33, 0.55] vs 0.32 [0.24, 0.38]; P = 0.0395). While children with Down syndrome also had significantly lower average oxygen saturation associated within each analysis window compared to typically developing children (mean ± standard deviation: 96.9 ± 1.3% vs 98.0 ± 1.0%; P = 0.0155), loop gain was not related to polysomnographic measures of hypoxia., Conclusions: Higher loop gain in children with Down syndrome and sleep disordered breathing indicates that these children have more unstable ventilatory control, compared to age, sex and sleep disordered breathing severity matched typically developing children. This may be due to an inherent impairment in ventilatory control in children with Down syndrome contributing to their increased risk of sleep disordered breathing which may inform alternative treatment options for this population., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

Objectives: In adults there is a distinct gender difference in the prevalence and severity of sleep disordered breathing (SDB), however there have been limited studies examining the effects of gender in children with SDB. We aimed to compare the effects of gender on severity of SDB, blood pressure, sleep and respiratory characteristics, quality of life, behavior and executive function., Methods: We included 533 children aged 3-18 years, who underwent standard pediatric overnight polysomnography (PSG) between 2004 and 2016. Blood pressure was recorded prior to each study. Quality of life, behavior and executive function were assessed with parental questionnaires. Children were grouped by gender and SDB severity based on their obstructive apnea hypopnea index (OAHI) into non-snoring controls, Primary Snoring (PS) (OAHI≤1 event/h), Mild obstructive sleep apnea (OSA) (OAHI>1-≤5 events/h) and moderate/severe (MS) OSA (OAHI>5 events/h) and data compared with 2-way ANOVA., Results: A total of 298 boys and 235 girls were studied. There were no differences in age, BMI z-score, SDB severity sleep characteristics or blood pressure between genders. Diastolic blood pressure was elevated in females with MS OSA compared to males (P < 0.05). Quality of life, behavior and executive function scores were all elevated in the SDB groups compared to controls. Females with MS OSA exhibited more internalizing behavioral problems compared to males (59.2 ± 2.4 vs. 51.4 ± 2.3, P < 0.05)., Conclusions: In contrast to studies in adults, we identified no gender differences in the severity or consequences of SDB in children, other than females with moderate-severe OSA exhibiting more internalizing problems and higher diastolic blood pressure., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

Background: The prevalence of obese children with sleep disordered breathing (SDB) is increasing. Obesity and SDB are independent cardiovascular risk factors, of which arterial stiffness is an early sign. Pulse wave velocity (PWV), is a marker of arterial stiffness and central systolic blood pressure (cSBP) is a better predictor of cardiovascular outcome than peripheral blood pressure. Therefore, we aimed to determine PWV and cSBP in overweight/obese or normal weight children with sleep disordered breathing (SDB), and non-snoring normal weight controls., Methods: Children (3-18 y) with SDB (overweight/obese [BMI z-scores ≥ 1.04], n = 48; normal weight n = 44) referred for clinical assessment of SDB and normal weight non-snoring controls recruited from the community (n = 38) underwent overnight polysomnography. PWV was calculated using photoplethysmography. cSBP was calculated using applanation tonometry in a subset of children older than 8 y (n = 55) who had usable waveforms., Results: Overweight/obese SDB group had higher PWV (mean cm/s (95% CI); wake: 366 (355-380); sleep: 340 (324-357)), than the normal-weight SDB group (wake: 257 (247-267), p = 0.002; sleep: 255 (242-269), p = 0.005), and non-snoring controls (wake: 238 (226-249), p = 0.002; sleep: 235 (220-250), p < 0.001). The normal-weight SDB group had higher PWV than controls (p = 0.03). Overweight/obese children with SDB had higher cSBP (105 (100-110) mmHg) compared with the normal weight children with SDB (96 (90-102)) and the non-snoring controls (97 (91-104); p < 0.05 for both)., Conclusion: This study suggests that overweight/obesity substantially worsens the cardiovascular sequelae of SDB, highlighting the imperative to treat obesity and SDB in children early in order to reduce future cardiovascular disease risk., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Up to 50% of overweight/obese children have obstructive sleep apnea (OSA) compared to up to 6% of normal weight children. We compared cardiovascular variables between normal weight and overweight/obese children with and without OSA, and controls., Methods: Seventy-four referred children and 24 normal weight non-snoring controls (8-18 years) were recruited. Referred children were grouped according to their obstructive apnea hypopnea index (OAHI): OSA (>1 event/h) or primary snoring (PS ≤ 1 event/h) and whether they were normal weight (BMI z-score <1.04) or overweight/obese (BMI z-score ≥ 1.04). Wake blood pressure (BP), heart rate (HR), and pulse transit time (PTT, an inverse continuous surrogate measure of blood pressure) during sleep were recorded., Results: Wake BP was higher in the overweight/obese OSA group than in the control, normal weight PS, and overweight/obese PS groups (p < 0.05 for all). During sleep, BP, and HR were elevated in the overweight/obese OSA group compared to those in non-snoring controls (p < 0.05). More children who were overweight/obese had reduced BP and HR dipping from wake to sleep than normal weight children. The BMI z-score predicted HR and PTT when asleep and both age and BMI z-score predicted BP when awake., Conclusion: This study showed that BMI has both combined and independent effects on BP and HR in children with OSA. We have previously shown that treatment of OSA reduces BP and suggest that treatment of OSA in the growing number of overweight/obese children may improve cardiovascular outcomes., (Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.)

Objective: This study aimed to determine whether overweight and obesity increased the detrimental effects of pediatric sleep-disordered breathing (SDB) on cognition, behavior, mood, and quality of life., Methods: Children and adolescents (8-16 years) with clinically diagnosed SDB were categorized into two groups: healthy weight (Body Mass Index (BMI) z-score <1.04, N = 11) and overweight/obese (BMI z-score ≥ 1.04, N = 10). Age-matched healthy weight, non-snoring controls (N = 25) were recruited from the community. All participants underwent overnight laboratory polysomnography (PSG). Cognitive, behavioral, and quality of life assessments were conducted in the home following the PSG. Analysis of Covariance (ANCOVA) was used to assess group differences in cognitive outcomes, controlling for socio-economic status. Kruskal-Wallis ANOVA was used to determine group differences in behavior and quality of life. Where group differences were found, hierarchical linear regressions determined the effect of weight on outcomes., Results: Children with SDB had significantly poorer behavior and quality of life than controls, with overweight/obese children with SDB having the greatest dysfunction. No group differences were found in cognitive outcomes. The obstructive apnea hypopnea index (OAHI) was a significant predictor of withdrawn behavior (R 2  = 0.42), inattention (R 2  = 0.43), and aggressive behavior (R 2  = 0.30). BMI z-score added significantly to aggressive behavior (R 2  = 0.22) and was an independent predictor of externalizing behaviors (R 2  = 0.26). The OAHI predicted school functioning (R 2  = 0.30). BMI z-score predicted social functioning (R 2  = 0.38) and significantly added to physical functioning over the OAHI (OAHI R 2  = 30; BMI z-score R 2  = 0.37)., Conclusions: Overweight and obesity comorbid with SDB increase the risk of externalizing behaviors such as aggression but do not affect other behavioral associates of SDB such as inattention and school functioning., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: In both adults and children, obstructive sleep apnea (OSA) has significant adverse cardiovascular consequences. In adults, sleeping position has a marked effect on the severity of OSA; however, the limited number of studies conducted in children have reported conflicting findings. We aimed to evaluate the effect of sleeping position on OSA severity and the cardiovascular consequences in preschool-aged children., Methods: This was a retrospective analysis of children (3-5 years of age) diagnosed with OSA (n = 75) and nonsnoring controls (n = 25). Sleeping position was classified as supine, semi-supine, left lateral, right lateral, prone, and semi-prone by using video recordings during one night of attended polysomnography. OSA severity and cardiovascular parameters were compared between the positions., Results: All children spent significantly more sleep time in the supine position than in any other position. The obstructive apnea-hypopnea index was higher in the supine position than in the other sleeping positions during NREM (p < 0.05), higher in the moderate/severe OSA group when sleeping in the supine position than when sleeping in the left and right lateral positions (p < 0.05 for both) and prone position (p = 0.007) during REM. Sympathovagal balance was decreased in children with OSA in the supine and lateral positions (p < 0.05)., Conclusions: This study identified that preschool-aged children, whether nonsnoring controls or children with OSA, predominately sleep in the supine position, and OSA was more severe in the supine position. We suggest that to avoid the supine sleep position, positional therapy has the potential to ameliorate OSA severity, and the known cardiovascular consequences., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Introduction: Little is known about the pediatric population at an increased risk of restless legs syndrome (RLS) and periodic limb movement disorder (PLMD). Polysomnographic data from the Caffeine for Apnea of Prematurity-Sleep (CAPS) study showed a high prevalence of elevated periodic limb movement index (PLMI) in a cohort of ex-preterm children, but the clinical importance of this finding, such as association with RLS, is unknown. We hypothesized that ex-preterm children would have a high prevalence of RLS and PLMD., Methods: Ex-preterm children enrolled in CAPS, now aged 5-12 years, completed home polysomnography (PSG) and standardized questionnaires. A diagnosis of RLS or PLMD was established by participants meeting the International Classification of Sleep Disorders, 3rd edition, criteria based on questionnaires and polysomnograms. The clinically available serum ferritin levels were assessed., Results: In total, 167 participants underwent polysomnography and completed all questionnaires. The overall prevalence of RLS was 14/167 (8.4%). An additional 13 subjects (7.8%) were found to have PLMD. Of the 26 participants who had PLMI > 5/h, seven (26.9%) had RLS and 13 (50%) had PLMD. The serum ferritin levels were <50 mcg/L (range -38.4) for all eight participants referred for testing., Conclusions: Children with a history of prematurity have a high prevalence of RLS, particularly those with elevated periodic limb movements. Iron deficiency likely contributes to RLS and PLMD symptoms in this population. Clinicians evaluating ex-preterm children with sleep disturbances should evaluate for RLS and PLMD. Further studies including serum ferritin evaluation are required to confirm these findings., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: It has been suggested that impaired dissipation of slow-wave activity (SWA) in children with sleep-disordered breathing (SDB) may be a potential mechanism for daytime dysfunction. We aimed to examine whether resolution of SDB resulted in normalisation of SWA dissipation and whether this was associated with improved cognition and behaviour., Methods: Children (aged 3-6 y) diagnosed with SDB and age-matched non-snoring control children were followed up for 3 y after a baseline study. At the follow-up, children were categorised into control (N = 13), resolved SDB (N = 15) and unresolved SDB (N = 14). Delta activity on the electroencephalogram over the sleep period was used to calculate SWA and a battery of cognitive assessments and behaviour questionnaires were conducted at both time points., Results: There was no change in the average SWA between the baseline and follow-up and no differences between the groups. Cognitive and behavioural performance in the resolved group did not improve to control levels. However, decreased SWA at the beginning of the sleep period (β = -0.04, p = 0.002) and a decrease in obstructive apnoea-hypopnoea index (β = -2.2, p = 0.022) between the baseline and follow-up predicted improvements in measures of sustained attention. Increased SWA at the beginning of the sleep period between the baseline and follow-up predicted worsening of externalising behaviour (β = 0.02, p = 0.039)., Conclusions: This study suggests that resolution of SDB is not associated with changes in the dissipation of SWA. However, the association between decreases in SWA and improvements in cognitive and behavioural outcomes suggest that irrespective of disease, children whose quantitative sleepiness improves have improved attention and reduced externalising behaviours., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective: Sleep-disordered breathing (SDB) is associated with reduced nocturnal dipping of blood pressure (BP) and sleep disruption in adults, and these features confer an increased risk of cardiovascular events. As SDB prevalence in children peaks during the preschool years, we investigated nocturnal dipping and sleep fragmentation in preschool children with SDB., Methods: Children (3-5 years; n=163) grouped by obstructive apnoea hypopnoea index (OAHI): control, no snoring history and OAHI ≤1 event/h; primary snoring, OAHI ≤1 event/h; mild SDB, >1-≤5 events/h; moderate-severe SDB, >5 events/h. Pulse transit time (PTT), an inverse continuous indicator of BP changes, and heart rate (HR) during total sleep time and the first period of rapid eye movement (REM), non-REM (NREM)1/2 and NREM3/4 sleep were expressed as percentage change from wake before sleep onset. The sleep fragmentation index (SFI) was calculated as the number of sleep stage transitions or awakenings per hour of sleep., Results: There were no group differences in the change in PTT or HR from wake to total sleep time or to individual sleep stages or in the proportion of children in the quartile with the smallest change in PTT during total sleep. Children with moderate-severe SDB had higher SFI than primary snoring (PS) or mild SDB groups (p<0.05 for both) and controls (p=0.07)., Conclusions: In contrast to adults, nocturnal dipping is preserved in young children with SDB, despite increased sleep fragmentation. As there is evidence that nocturnal dipping is similarly preserved at the school age, childhood may pose a window of opportunity for resolution of SDB when the cardiovascular effects are less marked., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Objective: Sleep-disordered breathing (SDB) in adults and children has been associated with reduced heart rate variability (HRV) indicative of autonomic dysfunction, which in turn is associated with an increased risk for cardiovascular morbidity. However, the long-term effects of pediatric SDB that has either resolved or remains unresolved on HRV are unknown., Methods: Forty Children with previously diagnosed SDB and 20 non snoring controls underwent repeat overnight polysomnography (PSG) four years after the original diagnosis. At follow-up, children aged 11 to 16 years were categorized into resolved (absence of snoring and obstructive apnea hypopnea index [OAHI]≤1) or unresolved (continued to snore or had an OAHI>1) groups. HRV was assessed using power spectral analysis for each sleep stage., Results: There were no group differences in age, sex or body mass index (BMI) z score. Both the resolved and unresolved SDB groups showed significant improvement in OAHI. The control, resolved, and unresolved groups all showed a significant reduction in total power (P<.001), low-frequency (LF) power (P<.05), high-frequency (HF) power (P<.001), and an increase in the LF/HF ratio (P<.001) from baseline to follow-up in all sleep stages., Conclusions: HRV did not differ between non snoring children and children with resolved and unresolved SDB four years after initial diagnosis, concomitant with a significant reduction in OAHI in both SDB groups. All groups demonstrated a decrease in HRV from baseline to follow-up which may reflect an age-related phenomenon in these children., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Objective: In adults sleep-disordered breathing (SDB) has been associated with impaired baroreflex control of blood pressure (BP), which has been linked to increased cardiovascular morbidity. In children, the long-term effects of SDB on baroreflex sensitivity (BRS) and BP variability (BPV) are unknown., Methods: Children previously diagnosed with SDB (n=40) and 20 nonsnoring controls aged 11-16 y underwent overnight polysomnography with continuous BP measurement, four years after the original diagnosis. At follow-up, SDB was categorized as resolved (absence of snoring and obstructive apnea hypopnea index (OAHI)≤1) or unresolved (continued to snore or had an OAHI>1). BRS and BPV were calculated using cross-spectral analysis and power spectral analysis, respectively., Results: Only children with resolved obstructive sleep apnea (OSA) at follow-up demonstrated an increase in BRS from 9.7±3 (ms mmHg(-1)) at baseline to 11.8±4 (ms mmHg(-1)) at follow-up (P=.03). However, children with all severities of both resolved and unresolved SDB showed a significant decrease in BPV from baseline to follow-up (a decrease in total power BPV (P<.05) and a shift in BPV spectra away from respiratory-related frequencies (increased low-frequency/high-frequency [LF/HF] ratio, P<.01). The change in OAHI was the sole determinant of change in BRS, HF power, and LF/HF ratio., Conclusions: Improvement in SDB was associated with improved BP control, regardless if SDB was treated or spontaneously resolved four years after initial diagnosis. Our findings highlight the importance of monitoring children to ensure improvement of SDB and reduce the risk for cardiovascular morbidity in the future., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Objective: Childhood sleep-disordered breathing (SDB) is associated with elevated blood pressure (BP); however, little is known about the long-term outcomes in this population. We aimed to assess long-term changes in overnight BP in children with SDB., Methods: Forty children with previously diagnosed SDB and 20 nonsnoring control participants underwent repeat overnight polysomnography (PSG) with continuous BP measurement 4years after the original diagnosis. At follow-up, children aged 11-16years were categorized into 2 groups of resolved (absence of snoring and obstructive apnea-hypopnea index [OAHI]⩽1) or unresolved (continued to snore or had an OAHI >1) SDB., Results: There were no group differences in age, sex, or body mass index (BMI) z score. OAHI was lower at follow-up (P<.05) in both the resolved (n=18) and unresolved (n=22) groups. BP was elevated during wake and sleep in both SDB groups compared to the control group at baseline (P<.01 for all), but it decreased by 5-15mmHg at follow-up during sleep for both SDB groups (P<.05 for all). BP during wake was unchanged in the SDB groups at follow-up but increased in the control group (P<.05). At follow-up, BP did not differ between the control group and the SDB groups during wake or sleep. Improved oxygen saturation (SpO2) during sleep was a significant predictor of a reduction in BP., Conclusions: SDB improved over the 4-year follow-up and both resolved and unresolved groups exhibited a significant reduction in BP during sleep, with levels similar to the control group. Our study highlights the fact that even small improvements can improve the cardiovascular effects of SDB., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Background: Obstructive sleep apnea (OSA) is associated with autonomic dysfunction in adults and school-aged children; however, this association has not been investigated in preschool children. We aimed to analyze heart rate variability (HRV) and catecholamine levels in preschool children with OSA., Methods: One hundred and forty-two snoring children aged 3-5years and 38 nonsnoring control group children underwent overnight polysomnography (PSG). Nocturnal urinary catecholamines were measured in 120 children. Children were grouped according to their obstructive apnea-hypopnea index (OAHI) (control [no snoring], OAHI⩽1event/h; primary snoring, OAHI⩽1event/h; mild OSA OAHI>1⩽5events/h; moderate to severe [MS] OSA, OAHI>5events/h). The HRV parameters for each child were averaged during rapid eye movement (REM) and non-REM (NREM) sleep., Results: During stable sleep, low-frequency (LF) HRV was similar between groups. High-frequency (HF) HRV was higher in the MS OSA group compared with the control group during all sleep stages (NREM sleep stages 1 and 2 [NREM1/2], 4234±523ms(2) vs 2604±457ms(2); NREM sleep stages 3 and 4 [NREM3/4], 4152±741ms(2) vs 3035±647ms(2); REM, 1836±255ms(2) vs 1456±292ms(2); P<.01 for all). The LF/HF ratio was lower in the MS OSA group compared with the control group (NREM1/2, 0.4±0.06 vs 0.7±0.05; NREM3/4, 0.3±0.06 vs 0.4±0.05; REM, 0.8±0.1 vs 1.3±0.1; P<.01 for all). Catecholamine levels were not different between groups., Conclusions: In preschool children, OSA is associated with altered HRV, largely due to the HF fluctuations in heart rate (HR) which occur during respiratory events and are still evident during stable sleep. The preschool age may represent a window of opportunity for treatment of OSA before the onset of the severe autonomic dysfunction associated with OSA in adults and older children., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Background: Surges in heart rate (HR) and blood pressure (BP) at apnea termination contribute to the hypertension seen in obstructive sleep apnea (OSA). Because childhood OSA prevalence peaks in the preschool years, we aimed to characterize the cardiovascular response to obstructive events in preschool-aged children., Methods: Clinically referred children aged 3-5 years were grouped by obstructive apnea-hypopnea index (OAHI) into the following: primary snoring (PS) (OAHI≤1 event/h [n=21]), mild OSA (OAHI>1-≤5 [n=32]), and moderate to severe (MS) OSA (OAHI>5 [n=28]). Beat-to-beat pulse transit time (PTT), an inverse continuous indicator of BP changes, and HR were averaged during the two halves (early and late) and during the peak after (post) each obstructive event and were expressed as percentage change from late- to post-event., Results: We analyzed 422 events consisting of 55 apneas and 367 hypopneas. A significant post-event increase in HR and fall in PTT occurred in all severity groups (P<.05 for all). A greater response was associated with OSA, nonrapid eye movement sleep (NREM), cortical arousal, hypopneas, and oxygen desaturation (P<.05 for all)., Conclusions: Obstructive events elicit acute cardiovascular changes in preschool children. Such circulatory perturbations have been implicated in the development of hypertension, and our findings complement previous studies to suggest a cumulative impact of snoring on the cardiovascular system from childhood into adulthood., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Background: Obstructive sleep apnea (OSA) in adults has been associated with hypertension, low baroreflex sensitivity (BRS), a delayed heart rate response to changing blood pressure (heart period delay [HPD]), and increased blood pressure variability (BPV). Poor BRS may contribute to hypertension by impairing the control of blood pressure (BP), with increased BPV and HPD. Although children with OSA have elevated BP, there are scant data on BRS, BPV, or HPD in this group., Methods: 105 children ages 7-12 years referred for assessment of OSA and 36 nonsnoring controls were studied. Overnight polysomnography (PSG) was performed with continuous BP monitoring. Subjects were assigned to groups according to their obstructive apnea-hypopnea index (OAHI): primary snoring (PS) (OAHI ≤1event/h), mild OSA (OAHI>1- ≤5events/h) and moderate/severe (MS) OSA (OAHI>5events/h). BRS and HPD were calculated using cross spectral analysis and BPV using power spectral analysis., Results: Subjects with OSA had significantly lower BRS (p<.05 for both) and a longer HPD (PS and MS OSA, p<.01; mild OSA, p<.05) response to spontaneous BP changes compared with controls. In all frequencies of BPV, the MS group had higher power compared with the control and PS groups (low frequency [LF], p<.05; high frequency [HF], p<.001)., Conclusions: Our study demonstrates reduced BRS, longer HPD, and increased BPV in subjects with OSA compared to controls. This finding suggests that children with OSA have altered baroreflex function. Longitudinal studies are required to ascertain if this dampening of the normal baroreflex response can be reversed with treatment., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objective: Little is known of the long-term prognosis of children treated for sleep disordered breathing (SDB) and even less of children with milder forms of SDB who remain untreated. We aimed to investigate the long-term sleep and respiratory outcomes of children with a range of SDB severities., Methods: 41 children with SDB and 20 non snoring controls (mean age, 12.9±0.2 y), underwent repeat overnight polysomnography (PSG) 4.0±0.3years after initial diagnosis. SDB severity, presence of snoring, sleep and respiratory parameters, sleep fragmentation index (SFI), the Pediatric Daytime Sleepiness Scale (PDSS), Sleep Disturbance Scale for Children (SDSC), and obstructive sleep apnea 18-item quality of life questionnaire were re assessed. Children with SDB were grouped into resolved (no snoring and obstructive apnea-hypopnea index [OAHI] <1) and unresolved (snoring or an OAHI > or =1)., Results: At follow-up OAHI was reduced in both SDB groups (p<0.05); however, 54% (n=22) of children still continued to snore, having either persistent or new OSA (n=4). In this unresolved group, sleep was significantly disrupted; % nonrapid eye movement stage 1 (NREM1) sleep and SFI were increased (p<0.05), and total sleep time (TST) and sleep efficiency were decreased compared to the resolved and control groups (p<0.05). Overall, 29% of children were treated, and of these, 67% had resolved SDB. SDB groups had higher PDSS, SDSC, and OSA-18 scores compared to controls at follow-up (p<0.01)., Conclusions: Our study demonstrated that although SDB improved in the long-term, more than 50% of children had residual SDB (mostly primary snoring) and sleep disturbance. As even mild forms of SDB are known to have adverse cardiovascular, learning, and behavioral outcomes, which have implications for the health of these children., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Background: Daytime deficits in children with sleep disordered breathing (SDB) are theorized to result from hypoxic insult to the developing brain or fragmented sleep. Yet, these do not explain why deficits occur in primary snorers (PS). The time course of slow wave EEG activity (SWA), a proxy of homeostatic regulation and cortical maturation, may provide insight., Methods: Clinical and control subjects (N=175: mean age 4.3±0.9 y: 61% male) participated in overnight polysomnography (PSG). Standard sleep scoring and power spectral analyses were conducted on EEG (C4/A1; 0.5-<3.9Hz). Univariate ANOVA's evaluated group differences in sleep stages and respiratory parameters. Repeated-measures ANCOVA evaluated group differences in the time course of SWA., Results: Four groups were classified: controls (OAHI ≤ 1 event/h; no clinical history); PS (OAHI ≤ 1 event/h; clinical history); mild OSA (OAHI=1-5 events/h); and moderate to severe OSA (MS OSA: OAHI>5 events/h). Group differences were found in the percentage of time spent in NREM Stages 1 and 4 (p<0.001) and in the time course of SWA. PS and Mild OSA children had higher SWA in the first NREM period than controls (p<0.05). All SDB groups had higher SWA in the fourth NREM period (p<0.01)., Conclusions: These results suggest enhanced sleep pressure but impaired restorative sleep function in pre-school children with SDB, providing new insights into the possible mechanism for daytime deficits observed in all severities of SDB., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objective: Childhood sleep disordered breathing (SDB) peaks in the preschool years. We aimed to compare the effects of SDB on polysomnographic characteristics between preschool and school aged children., Participants and Methods: One hundred and fifty-two preschool (3-5 y) and 105 school-aged (7-12 y) children, referred for assessment of SDB, plus controls (39, 3-5 y and 34, 7-12 y) with no history of snoring underwent overnight polysomnography. Subjects were grouped by their obstructive apnea hypopnea index (AHI) into those with primary snoring, mild obstructive sleep apnea (OSA), and moderate/severe OSA. The effects of SDB severity on sleep architecture and respiratory characteristics were compared between the age cohorts using quantile regression., Results: There was an average reduction in median sleep efficiency of 3.5% (p=0.004) and an average increase in median WASO of 2% (p=0.08) between the age cohorts across the severity groups, with sleep efficiency falling and WASO increasing with increasing SDB severity in the school-aged, but not the preschool, cohort. There was an average difference in median central AHI of 0.6 events/h (p<0.001) between the age cohorts across the severity groups, with the 3-5 y old cohort but not the 7-12 y old cohort having more central apneas with increasing SDB severity., Conclusions: We have demonstrated clinically important, age-related differences in sleep architecture in children with SDB. Preschool children with SDB maintain sleep efficiency and awaken fewer times throughout the night than do school aged children with a comparable severity of SDB, but experience more central apneas. This may have implications for the outcomes and treatment of SDB in children of different ages., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Sleep-disordered breathing (SDB) has been associated with impaired cognitive and behavioral function in school children; however, there have been limited studies in preschool children when the incidence of the disorder peaks. Thus, the aim of this study was to compare cognitive and behavioral functions of preschool children with SDB to those of non-snoring control children., Methods: A clinical sample of 3-5 year-old children (primary snoring [PS], n=60; mild obstructive sleep apnea syndrome [OSAS], n=32; moderate/severe [MS] OSAS, n=24) and a community sample of non-snoring control children (n=37) were studied with overnight polysomnography. Cognitive performance and behavioral information were collected., Results: Children with PS and mild OSAS had poorer behavior than controls on numerous measures (p<.05-p<.001), and on some measures they had poorer behavior than the MS OSAS group (p<.05). In contrast, all groups performed similarly on cognitive assessment. Outcomes related more to sleep than respiratory measures., Conclusions: SDB of any severity was associated with poorer behavior but not cognitive performance. The lack of significant cognitive impairment in this age group may have identified a "window of opportunity" where early treatment may prevent deficits arising later in childhood., (Copyright © 2012. Published by Elsevier B.V.)

Background: Parents consistently report working memory deficits in children with sleep-disordered breathing (SDB); however, results from objective testing measures are inconsistent. This study aims to examine and compare working memory performance in children with various degrees of severity of SDB using both parent report and objective testing., Methods: Subjects included 127 children aged 7-12 years (mean age 9.6 ± 1.6 y: 71 M/56 F). Overnight polysomnography classified subjects into four groups: control (N=34); primary snoring (PS: N=55), mild obstructive sleep apnoea (mild OSA: N=22) and moderate to severe OSA (MS OSA: N=16). The Behaviour Rating Inventory of Executive Function (BRIEF) was used as the parent reported measure of working memory. A computerised task involving immediate recognition of playing cards (CogHealth) was used as the objective measure., Results: Results of the BRIEF revealed working memory deficits at all severities of SDB compared to controls. Results of CogHealth revealed no difference between SDB groups and controls; however, mild OSA performed significantly worse than PS. Comparison of the two measures revealed that parents of controls reported less deficits, and parents of PS reported more deficits, than were found on the objective measure of working memory., Conclusions: This study showed that parents of children with less severe SDB have a tendency to overestimate the level of working memory deficit in their children, possibly as a reflection of behaviour. This suggests that observation of deficits in working memory may be largely dependent on the assessment method and children with SDB may not be as impaired as previously thought., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Study Objectives: Sleep-disordered breathing in children is most prevalent in the pre-school years and has been associated with sleep fragmentation and hypoxia. We aimed to compare the sleep and spontaneous arousal characteristics of 3-5-year-old children with obstructive sleep apnoea (OSA) with that of non-snoring control children, and to further characterise the arousal responses to obstructive respiratory events., Methods: A total of 73 children (48 male) underwent overnight polysomnography: 51 for assessment of snoring who were subsequently diagnosed with OSA (obstructive apnoea hypopnoea index (OAHI)>1 event per h) and 22 control children recruited from the community (OAHI ≤ 1 and no history of snoring)., Results: The OSA group had poorer sleep efficiency (p<0.05), spent a smaller proportion of their sleep period time in rapid eye movement (REM) (p<0.05), and had significantly fewer spontaneous arousals (p<0.001) compared with controls. One-quarter of the children with OSA had a sleep pressure score above the cut-off point for increased sleep pressure. In children with OSA, 62% of obstructive respiratory events terminated in a cortical arousal and 21% in a sub-cortical arousal. A significantly higher proportion of obstructive respiratory events terminated in a cortical arousal during non-REM (NREM) compared with REM (p<0.001)., Conclusions: These findings suggest that in pre-school children OSA has a profound effect on sleep and arousal patterns. Given that these children are at a critical period for brain development, the impact of OSA may have more severe consequences than in older children., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: Obstructive sleep apnea (OSA) is associated with increased sympathetic activity and hypertension in adults. We tested the hypothesis that children with OSA also have increased sympathetic activity as measured by overnight urinary catecholamines, and that this increase is related to the severity of OSA and to blood pressure (BP)., Methods: Seventy snoring children referred for assessment of sleep disordered breathing and 26 healthy non-snoring control children (age range: 3-12 years, 59 M/37 F) were studied. Overnight polysomnography was performed coincident with a 12h overnight urine collection. Urinary catecholamine levels were determined using high performance liquid chromatography (noradrenaline, adrenaline and dopamine, with levels adjusted for creatinine excretion). Simple linear and stepwise multiple linear regressions were used to determine the independent associations between catecholamine levels and age, gender, BMI z-score, systolic BP z-score, diastolic BP z-score, and apnea hypopnea index (AHI)., Results: Simple linear regressions revealed significant associations between noradrenaline and AHI (r = 0.32) and age (r = -0.20, p < 0.05 for both). Significant associations were also found between adrenaline and AHI (r = 0.27) and age (r = -0.25, p < 0.05 for both). Systolic BP z-score and diastolic z-score were both significantly associated with adrenaline (r = 0.22 and r = 0.20 respectively, p < 0.05 for both). Multivariate analysis revealed that only AHI was a significant independent predictor of noradrenaline (model R(2) = 0.10, p = 0.001). Similarly, only AHI and age were significant independent predictors of adrenaline (model R(2) = 0.12, p < 0.05)., Conclusions: This study demonstrates that levels of overnight urinary noradrenaline and adrenaline are related to the severity of OSA in children. These data indicate that children with OSA have increased sympathetic tone that may contribute to the cardiovascular consequences of the condition., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Study Objective: The impact of the broad spectrum of SDB severity on cognition in childhood has not been well studied. This study investigated cognitive function in children with varying severities of SDB and control children with no history of SDB., Methods: One hundred thirty-seven children (75 M) aged 7-12 were studied. Overnight polysomnography (PSG) classified children into four groups: primary snoring (PS) (n = 59), mild obstructive sleep apnea syndrome (OSAS) (n = 24), moderate/severe OSAS (n = 19), and controls (n = 35). Cognition was measured with a short battery of psychological tests including the Wechsler Abbreviated Scale of Intelligence (WASI), the Wide Range Achievement Test-3rd Edition (WRAT-3), the Rey Complex Figure Test (RCFT) and the Controlled Oral Word Association Test (COWAT)., Results: There was lower general intellectual ability in all children with SDB regardless of severity. Higher rates of impairment were also noted on measures of executive and academic functioning in children with SDB., Conclusions: Our findings suggest that neurocognitive deficits are common in children with SDB regardless of disease severity, highlighting that such difficulties may be present in children in the community who snore but are otherwise healthy; thus our results have important implications for the treatment of pediatric SDB., (Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.)

Objective: Sleep disordered breathing (SDB) is common in children and ranges in severity from primary snoring (PS), to obstructive sleep apnea syndrome (OSAS). This study investigated everyday function (behavior, attention, executive skills) in children with varying degrees of SDB and control children with no history of SDB recruited from the community., Methods: One hundred thirty-six children aged 7-12 were studied. Routine overnight polysomnography (PSG) classified children into 4 groups: PS (n=59), mild OSAS (n=24), moderate/severe OSAS (n=18), and controls (n=35). Behavioral function and behavioral aspects of attention and executive function were assessed using the Child Behavior Checklist (CBCL) and the Behavior Rating Inventory of Executive Function (BRIEF)., Results: Children with all severities of SDB had significantly higher rates of total, internalizing and externalizing behavioral problems compared to control children. Increased rates of behavioral executive dysfunction were also found across the SDB spectrum., Conclusion: Our findings suggest that behavioral, attention, and executive function difficulties are present in children with PS as well as OSAS. These results have implications for the treatment of milder forms of SDB, particularly PS, which is commonly viewed as benign., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Non-nutritive swallowing occurs frequently during sleep in infants and is vital for fluid clearance and airway protection. Swallowing has also been shown to be associated with prolonged apnea in some clinical populations. What is not known is whether swallowing contributes to apnea or may instead help resolve these clinically significant events. We studied the temporal relationships between swallowing, respiratory pauses and arousal in six preterm infants at term using multi-channel polysomnography and a pharyngeal pressure transducer. Results revealed that swallows occurred more frequently during respiratory pauses and arousal than during control periods. They did not trigger the respiratory pause, however, as most swallows (66%) occurred after respiratory pause onset and were often tightly linked to arousal from sleep. Swallows not associated with respiratory pauses (other than the respiratory inhibition to accommodate swallowing) and arousal occurred consistently during the expiratory phase of the breathing cycle. Results suggest that swallowing and associated arousal serve an airway protective role during sleep and medically stable preterm infants exhibit the mature pattern of respiratory-swallowing coordination by the time they reach term.

Arousals from sleep and consequent sleep disruption may be a causal link between sleep-disordered breathing and its sequellae in children. Quantification of arousals therefore makes an important contribution to the overall assessment of the sleep of a child with suspected obstructive sleep apnea (OSA) or other sleep disorders. Arousals are classically defined by changes in the electroencephalographic (EEG) channels, but most arousals in children involve body movement in addition to EEG changes. Several methods of quantifying arousals without the use of EEG have been proposed, with the aim of simplifying testing in children with suspected OSA so that it can be safely and efficiently performed in the child's home. The following paper gives a background to the assessment of arousals from sleep in children, and describes methods for detecting arousals and their potential application to recordings performed in a child's home.