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Rationale: Sleep-disordered breathing (SDB) is associated with increased vascular resistance in children and adults. Persistent increased vascular resistance damages vascular endothelial cells-a marker of which is increased platelet activation.Objectives: This study compared whole-blood impedance platelet aggregation in children with clinically diagnosed SDB warranting adenotonsillectomy and healthy control subjects.Methods: Thirty children who had SDB warranting intervention clinically diagnosed by experienced pediatric otolaryngologists were recruited from adenotonsillectomy waitlists, and 20 healthy children from the community underwent overnight polysomnography to determine SDB severity (obstructive apnea-hypopnea index). Snoring frequency was collected from parents. In the morning, a fasting blood sample was taken, and whole-blood platelet aggregation was measured.Measurements and Main Results: Children with SDB exhibited increased platelet aggregation to TRAP (thrombin receptor-activating peptide) (children with SDB = 114.8 aggregation units [AU] vs. control subjects = 98.0 AU; P < 0.05) and COL antibody (96.7 vs. 82.2 AU; P < 0.05) and an increased trend in ADP antibody (82.3 vs. 69.2 AU; P < 0.07) but not aspirin dialuminate (82.1 vs. 79.5 AU; P > 0.05). No significant association was observed between either the obstructive apnea-hypopnea index and any aggregation parameter, but parental report of snoring was positively associated with TRAP aggregation (Kendall's τ-c = 0.23; P < 0.05).Conclusions: The finding of increased platelet aggregation is consistent with endothelial damage. This suggests that the profile of cardiovascular changes noted in adults with SDB may also occur in children with SDB. Refereed/Peer-reviewed

Sleep-disordered breathing (SDB) is associated with cardiovascular disease and systemic inflammation in adults but this remains to be explored in children, especially in children with the most common form of SDB, i.e. primary snoring/mild SDB. This pilot study investigated the relationship between the cardiovascular function and inflammation in children with mild SDB. Nineteen participants aged 5–14 years underwent overnight polysomnography, cardiac magnetic resonance imaging (aortic blood flow velocity and left and right ventricular systolic function) and assessment for inflammatory markers (intracellular cytokine analysis of T cells by flow cytometry). Parents also completed the Sleep Disturbances Scale for Children (SDSC). Children with mild SDB exhibited increased ascending aortic peak systolic velocity compared to controls (SDB 119.95 m/s vs. control 101.49 m/s, p < 0.05). No significant group differences were observed for left and right ventricular ejection fraction or mean aortic blood flow velocity from either the ascending aorta or pulmonary artery. Children with mild SDB had increased inflammatory markers as demonstrated by elevated T cell interferon gamma (IFNγ) (SDB 52 ± 4% vs. control 25 ± 3% positive cells, p < 0.005) and tumour necrosis factor alpha (TNFα) (SDB 39 ± 4% vs. control 20 ± 2% positive cells, p < 0.005) expression from CD8 + cells. A strong positive correlation was observed between ascending aorta peak blood flow velocity and both TNFα and IFNγ (TNFα, r = 0.54, p < 0.03; IFNγ, r = 0.63, p < 0.005, respectively). Polysomnography revealed that oxygen saturation (SaO 2 ) nadir was significantly lower in children with mild SDB compared to controls (SDB 92.3 ± 2.7% vs. control 94.4 ± 1.6%, p < 0.05). A lower SaO 2 nadir was associated with an increased ascending aorta peak systolic velocity (r = − 0.48, p < 0.05). As well, both a lower SaO 2 nadir and an increased ascending aorta peak systolic velocity were associated with higher SDSC Sleep-Disordered Breathing and Disorder of Initiating and Maintaining Sleep subscale scores but not the polysomnographic-derived Obstructive Apnea–Hypopnea Index. The finding of elevated ascending aortic peak systolic blood flow velocity and its association with increased inflammatory markers suggests that the profile of cardiovascular changes noted in adult SDB may also occur in children with mild SDB. Refereed/Peer-reviewed

Studies suggest that there may be an association between sleep and growth; however, the relationship is not well understood. Changes in biology and external factors such as school schedule heavily impact the sleep of adolescents, during a critical phase for growth. This study assessed the changes in sleep across school days, weekends and school holidays, while also measuring height and weight changes, and self-reported alterations in food intake and physical activity. The impact of morningness–eveningness (M-E) on height change and weight gain was also investigated. In a sample of 63 adolescents (mean age = 13.13, SD = 0.33, 31 males) from two independent schools in South Australia, height and weight were measured weekly for 4 weeks prior to the school holidays and 4 weeks after the school holidays. Participants also completed a Morningness/Eveningness Scale and 7-day sleep, diet and physical activity diaries prior to, during and after the school holidays. Participants at one school had earlier wake times during the weekends than participants attending the other school, leading to a significantly shorter sleep duration on weekends for those participants. Regardless of school, sleep was significantly later and longer during the holidays (p < 0.001) and those with a stronger morning preference fell asleep (F 18,36 = 3.4, p = 0.001) and woke (F 18,44 = 2.0, p = 0.027) earlier than evening types. Growth rate was lower during the holiday weeks. For those attending the school with limited sleep in opportunities, growth after the holidays was lower for those with greater evening preference, whereas for those at the other school, growth was greater for those with greater evening preference. The increase in average weight from pre- to post-holidays was greater for those attending the school with limited opportunities to sleep longer. Participants reported greater food intake during the holidays compared to school days and greater physical activity levels on weekends compared to school days, and school days compared to holidays. Results suggest that time of day preference may impact growth, with evening types who cannot sleep in growing at a slower rate than evening types who can or morning types. This may be related to sleep restriction. Despite sleep being both later and longer during the school holidays, participants’ growth slowed during the holiday period. It is possible that this may be a reflection of other behavioural changes in the holidays (increased food intake and reduced physical activity), as sleep timing during the school period was related to growth. Refereed/Peer-reviewed

Background Sleep disordered breathing in children is associated with increased blood flow velocity and sympathetic overactivity. Sympathetic overactivity results in peripheral vasoconstriction and reduced systemic vascular compliance, which increases blood flow velocity during systole. Augmented blood flow velocity is recognized to promote vascular remodeling. Importantly, increased vascular sympathetic nerve fiber density and innervation in early life plays a key role in the development of early‐onset hypertension in animal models. Examination of sympathetic nerve fiber density of the tonsillar arteries in children undergoing adenotonsillectomy for Sleep disordered breathing will address this question in humans. Methods and Results Thirteen children scheduled for adenotonsillectomy to treat sleep disordered breathing underwent pupillometry, polysomnography, flow‐mediated dilation, resting brachial artery blood flow velocity (velocity time integral), and platelet aggregation. The dorsal lingual artery (tonsil) was stained and immunofluorescence techniques used to determine sympathetic nerve fiber density. Sympathetic nerve fiber density was correlated with increased resting velocity time integral ( r =0.63; P r =−0.71, P r =−0.64; P r =−0.77; P r =0.64; P P P Conclusions These results indicate that sympathetic activity is associated with change in both the function and structure of systemic vasculature in children with sleep disordered breathing.

Study Objectives: To develop a measure of sleep fragmentation in children with upper airway obstruction based on survival curve analysis of sleep continuity Design: Prospective repeated measures Setting: Hospital sleep laboratory. Participants: 92 children aged 3.0 to 12.9 years undergoing 2 overnight polysomnographic (PSG) sleep studies, 6 months apart. Subjects we redivided into 3 groups based on their obstructive apnea and hypopnea index (OAHI) and other upper airway obstruction (UAO) symptoms: primary snorers (PS; n = 24, OAHI < 1), those with obstructive sleep apnea syndrome (OSAS; n = 20, OAHI ≥ 1) and non-snoring controls (C; n = 48,OAHI < 1). Interventions: Subjects in the PS and OSAS groups underwent tonsillectomy and adenoidectomy between PSG assessments Measurements and Results: Post hoc measures of movement and contiguous sleep epochs were exported and analyzed using Kaplan-Meierestimates of survival to generate survival curves for the 3 groups. Statistically significant differences were found between these group curves forsleep continuity (P < 0.05) when using movement events as the sleep fragmenting event, but not if stage 1 NREM sleep or awakenings were used. Conclusion: Using conventional indices of sleep fragmentation in survival curve analysis of sleep continuity does not provide a useful measureof sleep fragmentation in children with upper airway obstruction. However, when sleep continuity is defined as the time between gross bodymovements, a potentially useful clinical measure is produced. Refereed/Peer-reviewed

Objective: The aim of the study was to examine sleep, neurocognitive and behavioural functioning in children and adolescents with type 1 diabetes (T1D) compared to controls and to test whether sleep quality mediates the relationship between diabetes and neurocognitive and behavioural deficits. Conclusions: Rather than the direct impact of T1D on daytime functioning, it is the consequent impact of T1D on sleep and the resulting sleep disruption which can explain much of the neurocognitive and behavioural deficits reported in children with T1D. Maintaining good nocturnal glycaemic control may play a much larger role than previously thought in regulating daytime functioning in children with T1D. Methods: Participants include 49 children and adolescents with T1D (recruited from a hospital clinic) and 36 healthy controls (age range = 6-16 years). Parents completed a survey consisting of the Sleep Disturbances Scale for Children, the Behavior Rating Inventory of Executive Functions, and the Behavior Assessment System for Children-2. Diabetic and demographic parameters were collated from medical records. The survey was posted to participants. Results: Children with T1D compared to controls reported a higher frequency of sleep problems, and mild deficits in executive and behavioural functioning. Mediational analyses revealed that sleep quality fully mediated metacognitive functioning, externalised problematic behaviour, and internalised problematic behaviour, but not behavioural regulation. Refereed/Peer-reviewed

Rationale: Event-related brain potentials allow probing of cortical information processing, but when evoked with externally induced stimuli may disrupt sleep homeostasis and do not provide insight into intrinsic cortical information processing. To investigate if cortical processing of intrinsic information in children with sleep-disordered breathing (SDB) is different from healthy children and, if so, whether it resolves with treatment, we used heartbeat as a source of interoceptive event-related brain potentials. Objectives: To investigate heartbeat evoked potentials (HEP) during sleep in healthy children and in children with SDB before and after treatment and to explore if there are any associations between HEP and daytime behavioral deficits in children with SDB. Methods: Heartbeat-aligned EEG was assessed for presence of HEP within stage 2, slow-wave sleep, and REM sleep in 40 children with primarily mild to moderate SDB before and after adenotonsillectomy and in 40 matched control subjects at similar time points. Measurements and Main Results: In both groups, nonrandom HEP were present in all sleep stages analyzed; however, amplitude of HEP were significantly lower in children with SDB during non-REM sleep (stage 2: P = 0.03; slow-wave sleep: P = 0.001). This between-group difference was not significant post adenotonsillectomy. Significant negative associations between HEP and daytime behavioral scores were observed at baseline. Conclusions: Children with SDB displayed reduced HEP amplitude during sleep, which might be indicative of changes in afferent sensory inputs to the brain and/or signify differences in sensory gating of cardiac-related information in the insular cortex. Adenotonsillectomy appears to reverse this effect. Refereed/Peer-reviewed

Objective: Sleepwalking is common in children, however, the relationship between sleepwalking, bedtime routine and daytime problems is poorly understood. We assessed the prevalence of parent reported sleepwalking in school children, and its relationship with broader sleep and daytime difficulties. Methods: Parents of 1814 children aged 5 to 10 years reported on child sleepwalking, other sleep behavior, emotional and daytime behavioral functioning. Results: Parents reported that 10.5% of children had sleepwalked in the previous week. There were no sex differences in sleepwalking prevalence, however middle children were reported to sleepwalk more than other children. Sleepwalking was associated with more problems of bedtime routine, bedtime anxiety, and daytime tiredness, as well as more sleep terrors, sleep talking, disordered sleep breathing symptoms, restless sleep and bruxism; however, these correlations were very small. Sleepwalkers also had significantly more emotional problems, conduct problems, and hyperactivity. Post hoc analyses showed that after controlling for sleep disordered breathing and sleep terrors, sleepwalking no longer contributed to the prediction of emotional, conduct, or hyperactivity problems, or morning tiredness. Results for the relationship between sleep instability and sleepwalking were mixed. Conclusions: Frequent sleepwalking is common in children and is associated with a range of sleep and behavior problems. However, behavioral and emotional problems associated with sleepwalking are accounted for by comorbid sleep disorders. Risk for other sleep related problems and impact on daytime functioning in children who sleepwalk warrant assessment and treatment. Similarly, children presenting with behavioral concerns should be assessed for sleep Refereed/Peer-reviewed

Sleep-disordered breathing (SDB) in children is assessed by quantification of hypopnea and apnea events. Little is known, however, about respiratory timing and breath-to-breath variability during sleep. The aim of this study was to investigate respiratory parameters across sleep stages in children with SDB before and after treatment compared with healthy children. Overnight polysomnography (PSG) was conducted in 40 children with SDB prior to and 6 mo following adenotonsillectomy. For comparison, a control group of 40 healthy sex- and age-matched children underwent two PSGs at equivalent time points but without intervention. The following variables were measured breath by breath during obstruction-free periods in stage 2 nonrapid eye movement (NREM), stage 4 NREM, and REM sleep: inspiratory time (Ti), expiratory time (Te), total time (Ttotal), inspiratory duty cycle (DC; =Ti/Ttotal), respiratory frequency (fR), and SD of the parameters Ti, Te, fR, and DC. Variability in waveform morphology was also computed using the residue of respiratory patterns. The severity of SDB was relatively mild in the study cohort (obstructive apnea hypopnea index: baseline, 5.1 ± 9.4 vs. 0.1 ± 0.2, P < 0.001; follow-up, 0.3 ± 0.3 vs. 0.8 ± 1.0, P < 0.01). Compared with healthy controls, children with SDB showed significantly longer Ti and Te and a lower fR at the baseline study. These differences were not significant after adenotonsillectomy. Sleep stages were associated with significant differences in all of the respiratory measures in both groups of children. In conclusion, children with relatively mild SDB showed prolonged inspiration and expiration indicative of chronic narrowing of the upper airway. Treatment of SDB normalizes respiratory timing. Documentation of these parameters may aid in both understanding and management of children with SDB. Refereed/Peer-reviewed

The efficacy of adenotonsillectomy for relieving obstructive sleep apnoea symptoms in children has been firmly established, but its precise effects on cardiorespiratory control are poorly understood. In 375 children enrolled in the Childhood Adenotonsillectomy Trial, randomised to undergo either adenotonsillectomy (n=194) or a strategy of watching waiting (n=181), respiratory rate, respiratory sinus arrhythmia and heart rate were analysed during quiet, non-apnoeic and non-hypopnoeic breathing throughout sleep at baseline and at 7 months using overnight polysomnography. Children who underwent early adenotonsillectomy demonstrated an increase in respiratory rate post-surgery while the watchful waiting group showed no change. Heart rate and respiratory sinus arrhythmia were comparable between both arms. On assessing cardiorespiratory variables with regard to normalisation of clinical polysomnography findings during follow-up, heart rate was reduced in children who had resolution of obstructive sleep apnoea syndrome, while no differences in their respiratory rate or respiratory sinus arrhythmia were observed. Adenotonsillectomy for obstructive sleep apnoea increases baseline respiratory rate during sleep. Normalisation of apnoea–hypopnoea index, spontaneously or via surgery, lowers heart rate. Considering the small average effect size, the clinical significance is uncertain., Adenotonsillectomy for childhood obstructive sleep apnoea increases respiratory rate during sleep http://ow.ly/Dptd300w9Pp

Objectives To compare neuropsychological and psychosocial function in children with a history of snoring, children with a history of behavioral sleep problems (BSP), children with both a history of snoring and BSP, and a group of control subjects. Study design Families awaiting consultation for “sick” visits in 5 general practice clinics completed the Sleep Disturbance Scale for Children. A subset of children were categorized into groups: Snorers (n = 11), BSP (n = 13), Snorers+BSP (n = 9), and controls (n = 31). Children underwent psychological (Wechsler Abbreviated Scale of Intelligence, Children's Memory Scale; Test of Everyday Attention and Auditory Continuous Performance Test) and psychosocial assessment (Child Behavior Checklist). Results With analysis of variance, it was revealed that, compared with children in the BSP and control groups, those in the Snorers+BSP and Snorers groups showed reduced intelligence and attention scores. By contrast, compared with children in the Snorers and control groups, children in the Snorers+BSP and BSP groups reported reduced social competency, increased problematic behavior, and reduced memory scores. Children in the combination of Snorers+BSP group showed more deficits than children in all other groups. Conclusion In children, snoring and BSP, separately and together, are associated with impaired neuropsychological and psychosocial functioning. Furthermore, snoring and BSP are related to performance in disparate ways. Snoring was associated with intelligence and attention deficits, whereas BSP was associated with memory and behavioral deficits.

Objective Heartbeat-evoked potentials (HEPs) in electroencephalogram (EEG) provide a quantitative measure of cardiac interoception during sleep. We previously reported reduced HEPs in children with sleep-disordered breathing (SDB), indicative of attenuated cardiac information processing. The objective of this study was to investigate the link between HEP and respiration. Patients/Methods From the overnight polysomnograms of 40 healthy children and 40 children with SDB, we measured HEPs during epochs of stage 2, slow-wave and rapid eye movement (REM) sleep free of abnormal respiratory events. HEPs were analysed with respect to respiratory phase. Results We observed a marked association between respiratory phase and HEP in children with SDB during REM sleep, but not in normal children. In children with SDB, HEP waveforms were attenuated during expiration compared to inspiration. Following adenotonsillectomy, expiratory HEP peak amplitude increased in the SDB children and was no longer different from those of normal children. Conclusions The expiratory phase of respiration is primarily associated with attenuated cardiac information processing in children with SDB, establishing a pathophysiological link between breathing and HEP attenuation.

Aim: This study aimed to evaluate whether the vascular dysfunction perceived in adults with sleep-disordered breathing (SDB) was also evident in children with snoring referred for evaluation of clinically suspected SDB. Objectives: This study compared flow-mediated dilatation (FMD), measured at the brachial artery, at rest and during hyperaemic stress between children who snore [. n = 23; mean standard deviation (SD) age = 7.51 (1.3) years] and healthy, non-snoring children [. n = 11; age = 8.0 (1.3) years]. Methods: Children with suspected obstructive sleep apnoea (OSA) and healthy non-snoring controls underwent overnight polysomnography (PSG). Using standard techniques, non-invasive FMD and brachial arterial blood flow velocity during rest and hyperaemia were subsequently measured by ultrasound imaging. Measurements: Resting and hyperaemic velocity time integral (area under the curve of mean systolic velocity × ejection time), maximal dilation response (highest percentage difference from baseline diameter) and the time taken to reach maximal dilation were calculated. Results: Children awaiting adenotonsillectomy compared to healthy non-snoring control children had higher velocity time integrals at rest (14 ± 3 m vs. 20 ± 8 m, p < 0.01) and during hyperaemic stress (56 ± 6m vs. 63 ± 13m, p < 0.01) despite having only mild SDB on polysomnographic assessment. Lower nadir oxygen saturation values during non-rapid eye movement sleep were negatively associated with higher resting (. r = -0.58, p

Flow-mediated dilatation (FMD) is a tool widely used to measure arterial responsiveness to sheer stress. However, there is scant literature to show how the peripheral arterial response changes as the vascular system matures. One reason for this is that the feasibility of measuring FMD in younger children has not been established. The aim of the present study was to assess brachial artery function at rest and during the FMD response after 4 min ischaemia of the forearm in children aged 6–15 years. Time to reach maximum FMD (FMDmax) was found to be correlated with age (r = 0.4, P < 0.05), resting brachial artery diameter (r = 0.4, P < 0.05), height (r = 0.4, P < 0.05), body mass index (BMI; r = 0.45, P < 0.05), body surface area (r = 0.44, P < 0.05) and resting blood flow (r = 0.37, P < 0.05). However, there was no correlation between the traditional FMD response at 60 s or FMD maximal dilation and age, resting brachial artery diameter, height, weight, BMI, body surface area and resting blood flow. In conclusion, the time taken to reach the maximal dilation response is related to age, brachial artery luminal diameter and body habitus, but not the traditional measure of FMD response at 60 s or the maximal dilatation percentage. Refereed/Peer-reviewed

Sleep disordered breathing in children is a common but largely underdiagnosed problem. It ranges in severity from primary snoring to obstructive sleep apnea syndrome (OSAS). Preliminary evidence suggests that children with severe OSAS show reduced neurocognitive performance, however, less is known about children who snore but do not have severe upper airway obstruction. Participants included 16 children referred to the Ear, Nose and Throat/Respiratory departments of a Children's Hospital for evaluation of snoring and 16 non-snoring controls aged 5-10 years. Overnight polysomnography (PSG) was carried out in 13 children who snored and 13 controls. The PSG confirmed the presence of primary snoring in seven and very mild OSAS (as evidenced by chest wall paradox) in eight children referred for snoring while controls showed a normal sleep pattern. To test for group differences in neurocognitive functioning and behavior, children underwent one day of testing during which measures of intelligence, memory, attention, social competency, and problematic behavior were collected. Compared to controls, children who snored showed significantly impaired attention and, although within the normal range, lower memory and intelligence scores. No significant group differences were observed for social competency and problematic behavior. These findings suggest that neurocognitive performance is reduced in children who snore but are otherwise healthy and who do not have severe OSAS. They further imply that the impact of mild sleep disordered breathing on daytime functioning may be more significant than previously realized with subsequent implications for successful academic and developmental progress.

STUDY OBJECTIVE To investigate respiratory cycle-related electroencephalographic changes (RCREC) in healthy children and in children with sleep disordered breathing (SDB) during scored event-free (SEF) breathing periods of sleep. DESIGN Interventional case-control repeated measurements design. SETTING Paediatric sleep laboratory in a hospital setting. PARTICIPANTS Forty children with SDB and 40 healthy, age- and sex-matched children. INTERVENTIONS Adenotonsillectomy in children with SDB and no intervention in controls. MEASUREMENTS AND RESULTS Overnight polysomnography; electroencephalography (EEG) power variations within SEF respiratory cycles in the overall and frequency band-specific EEG within stage 2 nonrapid eye movement (NREM) sleep, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Within both groups there was a decrease in EEG power during inspiration compared to expiration across all sleep stages. Compared to controls, RCREC in children with SDB in the overall EEG were significantly higher during REM and frequency band specific RCRECs were higher in the theta band of stage 2 and REM sleep, alpha band of SWS and REM sleep, and sigma band of REM sleep. This between-group difference was not significant postadenotonsillectomy. CONCLUSION The presence of nonrandom respiratory cycle-related electroencephalographic changes (RCREC) in both healthy children and in children with sleep disordered breathing (SDB) during NREM and REM sleep has been demonstrated. The RCREC values were higher in children with SDB, predominantly in REM sleep and this difference reduced after adenotonsillectomy. CITATION Immanuel SA, Pamula Y, Kohler M, Martin J, Kennedy D, Saint DA, Baumert M. Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.

Objective: This study aims to investigate the impact of upper airway obstruction (UAO) in children by measuring thoracoabdominal asynchrony (TAA) during periods of sleep apnea/hypopnea and during scored-event-free (SEF) breathing periods. Conclusion: Upper airway obstruction in children is associated with increased TAA during SEF periods, indicative of continuous partial obstruction of the upper airway. Adenotonsillectomy decreased this effect significantly in non-REM sleep as evidenced by reduced asynchrony levels post-surgery. TAA assessment during sleep may therefore provide additional diagnostic information. Methods: Respiratory inductive plethysmographic signals were extracted from polysomnographic data, recorded before and after adenotonsillectomy in 40 children with UAO and 40 healthy, matched children at equivalent time points. Thoracoabdominal asynchrony was computed using a Hilbert transform-based phase difference estimation method in SEF periods during stage 2, stage 4 non-rapid eye movement (NREM), and rapid eye movement (REM) sleep and compared between the groups. Results: At baseline, in the UAO group, TAA during obstructions were significantly higher than TAA during SEF periods in both stage 2 and REM sleep. Compared to controls, children with UAO had a significantly higher TAA during SEF periods in stage 2, stage 4 sleep, and REM sleep. This between-group difference was not significant post adenotonsillectomy. UAO group showed a significant decrease in TAA compared to their baseline during SEF stage 2 and 4 NREM, but not in REM. Refereed/Peer-reviewed

Study Objectives: To investigate the association between indices of sleep spindle activity and cognitive performance in a sample of healthy children. Conclusions: Basal sleep spindle activity is associated with different aspects of cognitive performance in children. To the extent that these associations in a pediatric population are different from what is known in adult sleep may play an important role in development. Design: Correlational. Intelligence (Stanford-Binet) and neurocognitive functioning (NEPSY) were assessed, with sleep variables being measured during overnight polysomnography. Interventions: N/A. Measurements and Results: Participants underwent a single night of overnight polysomnography after completing measures of intelligence and neurocognitive functioning. Sleep spindles were visually identified by an experienced sleep scoring technician and separated algorithmically into fast (> 13 Hz) and slow spindle (< 13 Hz) categories. The number of fast spindles was significantly correlated with narrative memory (rs = 0.38) and sensorimotor functioning (-0.43). Mean central frequency of spindles was also significantly correlated with sensorimotor functioning (-0.41), planning ability (-0.41), and working memory (-0.54). Participants: Twenty-seven healthy children (mean age 8.19 y; 14 female, 13 male). Setting: Hospital sleep laboratory. Refereed/Peer-reviewed

Study objectives: Based on recent reports of the involvement of cyclic alternating pattern (CAP) in cognitive functioning in adults, we investigated the association between CAP parameters and cognitive performance in healthy children. Design: Polysomnographic assessment and standardized neurocognitive testing in healthy children. Settings: Sleep laboratory. Participants: Forty-two children aged 7.6 ± 2.7 years, with an even distribution of body mass percentile (58.5 ± 25.5) and SES reflective of national norms. Measurements: Analysis of sleep macrostructure following the R&K criteria and of cyclic alternating pattern (CAP). The neurocognitive tests were the Stanford Binet Intelligence Scale (5th edition) and a Neuropsychological Developmental Assessment (NEPSY) Results: Fluid reasoning ability was positively associated with CAP rate, particularly during SWS and with A1 total index and A1 index in SWS. Regression analysis, controlling for age and SES, showed that CAP rate in SWS and A1 index in SWS were significant predictors of nonverbal fluid reasoning, explaining 24% and 22% of the variance in test scores, respectively. This study shows that CAP analysis provides important insights on the role of EEG slow oscillations (CAP A1) in cognitive performance. Children with higher cognitive efficiency showed an increase of phase A1 in total sleep and in SWS. Refereed/Peer-reviewed

Objective: Upper airway obstruction (UAO) during childhood is associated with cardiovascular morbidity. The aim of this study was to investigate the cardio-respiratory response to cortical arousal during sleep in children with UAO. Methods: Standard paediatric overnight polysomnography (PSG) was conducted in 40 children with UAO (25 M, 7.5 ± 2.7 yrs) prior to and 6 months following adenotonsillectomy. For comparison a control group of 40 normal, sex and age matched children (21 M, 7.5 ± 2.6 yrs) underwent two PSGs without intervention at the same time points. Results: Heart rate and respiratory rate were measured during spontaneous and respiratory arousals in stage 2 and REM sleep 15 s prior to and 15 s immediately following cortical arousal onset. Cortical arousal was associated with a significant increase in heart and respiratory rate in both groups of children. UAO children, however, showed a significantly higher heart rate response in stage 2 sleep ( 17.5 ± 6.0 vs. 14.4 ± 4.8%; p < 0.05), a lower pre-arousal baseline respiratory rate (stage 2: 17.1 ± 1.4 vs. 18.2 ± 1.7 BPM; p < 0.01) and a prolonged increase in respiratory rate compared to control children. Cardiac and respiratory arousal responses were not significantly different from controls following adenotonsillectomy in the UAO children. Conclusions: UAO in children is associated with an altered cardiorespiratory response to spontaneous arousal from sleep, which may indicate early signs of autonomic dysfunction. Surgical treatment of UAO appears to reverse these outcomes. Refereed/Peer-reviewed

The impact of sleep restriction on sustained attention in children has not been well quantified. To address this shortcoming, this study tested the sensitivity of a 5-minpersonal digital assistant-psychomotor vigilance task (PDA-PVT) to sleep restriction in14 female children [mean (SD) age = 10.6 ± 0.3 years]. The children underwent PDA-PVT trials at regular intervals both before and after a sleep restriction (5 h time-in-bed)and a control (10 h time-in-bed) condition. Sleep restriction was associated with longer mean response times and increased number of lapses. These results are consistent withfindings in the adult literature suggesting an association between inadequate sleep and impaired functioning. In conclusion, the 5-min PDA-PVT is sensitive to sleep restriction in pre-adolescent female children supporting the utility of the PDA-PVTfor examining the impact of sleep deprivation on daytime functioning in children. Refereed/Peer-reviewed

Aim: To identify the time required by children with cystic fibrosis (CF), diabetes or asthma to complete daily treatment tasks and the hassle they experienced when completing these tasks. To compare parent and child reports of daily treatment time and hassle. To investigate the relationship between treatment time and hassle, and (i) children’s health-related quality of life (HRQL); and (ii) disease severity. Methods: 160 children aged 10–16 years with CF, type 1 diabetes, or asthma were followed over a 2-year period. Information about children’s treatment time and hassle, and their HRQL was obtained from parents and children at baseline, 1-year and 2-year follow-up assessments. Results: On average, children with CF reported spending 74.6 ± 57.0 min completing treatment tasks, children with diabetes spent 56.9 ± 27.8 min and children with asthma spent 6.4 ± 9.3 min. Parents reported that children spent less time that was reported by their children. Over the two years, parent and child reports describing treatment time for children with CF did not vary significantly (P = 0.3). Treatment time for children with diabetes increased (P = 0.02) whereas that for children with asthma reduced (P = 0.001). The level of hassle experienced by children when completing individual treatment tasks was low for all three conditions. There was no significant relationship between treatment time and children’s HRQL. Conclusion: Children with CF or diabetes spent a substantial amount of time each day completing the treatment tasks. Although this was not related to HRQL, it could impact the ability to comply with complex and all home-based-therapies for some children.

Electroencephalograph (EEG) analysis enables the neuronal behavior of a section of the brain to be examined. If the behavior is nonlinear then nonlinear tools can be used to glean information on brain behavior, and aid in the diagnosis of sleep abnormalities such as obstructive sleep apnea syndrome (OSAS). In this paper the sleep EEGs of a set of normal and mild OSAS children are evaluated for nonlinear behaviour. We consider how the behaviour of the brain changes with sleep stage and between normal and OSAS children., Comment: 9 pages, 2 figures, 4 tables

This paper investigates the automated detection of a patient’s breathing rate and heart rate from their skin conductivity as well as sleep stage scoring and breathing event detection from their EEG. The software developed for these tasks is tested on data sets obtained from the sleep disorders unit at the Adelaide Women’s and Children’s Hospital. The sleep scoring and breathing event detection tasks used neural networks to achieve signal classification. The Fourier transform and the Higuchi fractal dimension were used to extract features for input to the neural network. The filtered skin conductivity appeared visually to bear a similarity to the breathing and heart rate signal, but a more detailed evaluation showed the relation was not consistent. Sleep stage classification was achieved with and accuracy of around 65% with some stages being accurately scored and others poorly scored. The two breathing events hypopnea and apnea were scored with varying degrees of accuracy with the highest scores being around 75% and 30%.

Background: Sleep Disordered Breathing (SDB) is a common childhood disorder that encompasses a range of sleep-related upper airway obstruction. Children with SDB demonstrate significant neurocognitive deficits. Adenotonsillectomy is the first line of treatment for SDB and whilst this improves respiratory disturbance, it remains to be established whether neurocognitive gains also result. Conclusion: Adenotonsillectomy successfully treated the respiratory effects of SDB in children. However, neurocognitive deficits did not improve 6-months post-operatively. Methods: A total of 44 healthy snoring children aged 3-12 years awaiting adenotonsillectomy (SDB group), and 48 age and gender matched non-snoring controls from the general community, completed the study. All children underwent polysomnography and neurocognitive assessment at baseline and after a 6-month follow-up (after surgery in the snoring group). Our primary aim was to determine whether neurocognitive deficits in snoring children were significantly improved following adenotonsillectomy. Results: Wide ranging neurocognitive deficits were found at baseline in SDB children compared to controls, most notably a 10 point IQ difference (P