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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.)

Background: Children with Down syndrome (DS) are at increased risk of sleep-disordered breathing (SDB). We investigated sleep spindle activity, as a marker of sleep quality, and its relationship with daytime functioning in children with DS compared to typically developing (TD) children., Methods: Children with DS and SDB (n = 44) and TD children matched for age, sex and SDB severity underwent overnight polysomnography. Fast or Slow sleep spindles were identified manually during N2/N3 sleep. Spindle activity was characterized as spindle number, density (number of spindles/h) and intensity (density × average duration) on central (C) and frontal (F) electrodes. Parents completed the Child Behavior Check List and OSA-18 questionnaires., Results: In children with DS, spindle activity was lower compared to TD children for F Slow and F Slow&Fast spindles combined (p < 0.001 for all). Furthermore, there were no correlations between spindle activity and CBCL subscales; however, spindle activity for C Fast and C Slow&Fast was negatively correlated with OSA-18 emotional symptoms and caregiver concerns and C Fast activity was also negatively correlated with daytime function and total problems., Conclusions: Reduced spindle activity in children with DS may underpin the increased sleep disruption and negative effects of SDB on quality of life and behavior., Impact: Children with Down syndrome (DS) are at increased risk of sleep-disordered breathing (SDB), which is associated with sleep disruption affecting daytime functioning. Sleep spindles are a sensitive marker of sleep quality. We identified for the first time that children with DS had reduced sleep spindle activity compared to typically developing children matched for SDB severity. The reduced spindle activity likely underpins the more disrupted sleep and may be associated with reduced daytime functioning and quality of life and may also be an early biomarker for an increased risk of developing dementia later in life in children with DS., (© 2023. The Author(s).)

Background and Objective: The contribution of non-anatomical factors, such as ventilatory control instability (i.e. LG), to the pathogenesis of obstructive SDB in children is unclear. Therefore, we aimed to identify the relationship between LG and severity of SDB, demographic, anthropometric and anatomical characteristics in a clinically representative cohort of children., Methods: Children (aged 3-18 years) with various severities of SDB (n = 110) and non-snoring controls (n = 36) were studied. Children were grouped according to their OAHI. Anthropometric and upper airway anatomical characteristics were measured. Spontaneous sighs were identified on polysomnography and LG, 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: There was no difference in LG between controls and any of the SDB severity groups. However, LG was significantly lower in children with larger tonsils (tonsil grade 4) compared with children with smaller tonsils (tonsil grade 1) (median LG (range): 0.25 (0.20-0.42) vs 0.32 (0.25-0.44); P = 0.009) and in children with a modified Mallampati score of class III/IV compared with class I (0.28 (0.24-0.33) vs 0.37 (0.27-0.44); P = 0.009)., Conclusion: A direct relationship was not found between the severity of paediatric SDB and LG. However, an altered ventilatory control sensitivity may contribute to SDB in a subgroup of children depending on their degree of anatomical compromise of the airway., (© 2020 Asian Pacific Society of Respirology.)

Purpose: Allergic rhinitis (AR) is a common risk factor for sleep disordered breathing (SDB) in children. Allergy to pollen is a trigger for allergic rhinitis, causing nasal inflammation, upper airway congestion and obstruction. We aimed to determine if the pollen count on the day of diagnostic polysomnography for SDB affected the result., Methods: Children (3-18 years; n = 90) who participated in research studies between 1 October and 31 December, when daily regional pollen counts were available, in the years 2005-2016 were eligible for inclusion. All children underwent overnight polysomnography for assessment of SDB severity. Pollen was categorised as grass or other pollen. Multiple stepwise linear regression was performed to determine whether the pollen count for that day, a diagnosis of asthma, age, and BMI-z-score were determinants of respiratory parameters measured on polysomnography, including the obstructive apnoea hypopnoea index (OAHI), SpO 2 nadir, average SpO 2 drop, SpO 2 < 90%, oxygen desaturation index > 4% (ODI4), and average transcutaneous CO 2 (TCM)., Results: Sixteen/90 children had AR. In children with AR, an increase in grass pollen of 1 grain/m 3 predicted an increase in OAHI of 0.2 events/h, ODI4 of 0.18 times/h, SpO 2 < 90% of 0.03 times/h, and TCM of 0.07 mmHg. None of the factors were determinants of SDB severity in children without AR., Conclusion: Our findings highlight that daily pollen counts may be an important factor influencing the severity of SDB on a single night of polysomnography in children with clinical allergic rhinitis and should be taken into account when determining treatment options.

Background: We aimed to investigate the relationship between sleep quality, mood and health-related quality of life (HRQOL) in children with CF and controls., Methods: Children (7-12years) and adolescents (13-18years) with CF and controls completed sleep evaluation: overnight oximetry and 14days of actigraphy. Age-appropriate questionnaires assessed mood (Children's Depression Inventory; CDI or Beck's Depression Inventory), HRQOL (CF Questionnaire-Revised; CFQ-R or PedsQL), and sleepiness (Pediatric Daytime Sleepiness Scale)., Results: 87 CF and 55 controls recruited. Children with CF had poorer sleep quality, more sleepiness and lower mood than controls, with a negative correlation between mood score and sleep efficiency. Sleepiness score was predictive of mood score and multiple CFQ-R domains. Adolescents with CF also demonstrated poorer sleep and more sleepiness than controls, but no difference in mood. Reduced sleep quality predicted lower CFQ-R scores. No correlation between sleep, mood or HRQOL in controls., Conclusions: In children and adolescents with CF, impaired sleep quality is associated with lower mood and HRQOL in an age-specific manner. Future research will aid understanding of effective strategies for prevention and treatment of mood disorders and sleep disturbance in children with CF., (Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.)

Study Objectives: To compare two commercial sleep devices, an accelerometer worn as a wristband (UP by Jawbone) and a smartphone application (MotionX 24/7), against polysomnography (PSG) and actigraphy (Actiwatch2) in a clinical pediatric sample., Methods: Children and adolescents (n = 78, 65% male, mean age 8.4 ± 4.0 y) with suspected sleep disordered breathing (SDB), simultaneously wore an actiwatch, a commercial wrist-based device and had a smartphone with a sleep application activated placed near their right shoulder, during their diagnostic PSG. Outcome variables were sleep onset latency (SOL), total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE). Paired comparisons were made between PSG, actigraphy, UP, and MotionX 24/7. Epoch-by-epoch comparisons determined sensitivity, specificity, and accuracy between PSG, actigraphy, and UP. Bland-Altman plots determined level of agreement. Differences in bias between SDB severity and developmental age were assessed., Results: No differences in mean TST, WASO, or SE between PSG and actigraphy or PSG and UP were found. Actigraphy overestimated SOL (21 min). MotionX 24/7 underestimated SOL (12 min) and WASO (63 min), and overestimated TST (106 min) and SE (17%). UP showed good sensitivity (0.92) and accuracy (0.86) but poor specificity (0.66) when compared to PSG. Bland-Altman plots showed similar levels of bias in both actigraphy and UP. Bias did not differ by SDB severity, however was affected by age., Conclusions: When compared to PSG, UP was analogous to Actiwatch2 and may have some clinical utility in children with sleep disordered breathing. MotionX 24/7 did not accurately reflect sleep or wake and should be used with caution., (© 2016 American Academy of Sleep Medicine.)

Purpose: Overnight oximetry is a simple tool for investigation of obstructive sleep apnoea (OSA) in children, but only severe cases will be detected, and children with obstructive events resulting in arousal, but not desaturation, will have a normal (inconclusive) result. We hypothesised that pulse rate rises using pulse rate indices per hour (PRI) and pulse rate standard deviation (PR-SD) automatically calculated from commercially available software would improve oximetry as a diagnostic tool., Methods: Children having home overnight oximetry for suspected OSA were identified over 12 months, and those with a normal result who went on to have polysomnography (PSG) were included. Oximetry, including PR-SD and PRI (rises of 8, 10 and 15 beats/min per hour), was analyzed using commercially available software. PR parameters were compared between those with OSA (obstructive apnoea-hypopnoea index (OAHI) >1 event/h) and those without OSA., Results: One hundred sixteen children had normal oximetry, of whom 93 (median age 4.5 years; 55 % M) had PSG. Fifty-seven of 93 (61 %) children had OSA (median OAHI 4.5 events/h, range 1.1-24). PR-SD was not different between the OSA and non-OSA groups (p = 0.87). PRI tended to be higher in those with OSA, but there was considerable overlap between the groups: PRI-8 (mean ± SD 58.5 ± 29.0/h in OSA group vs 48.6 ± 20.2/h in non-OSA group, p = 0.07), PRI-10 (45.1 ± 25.0 vs 36.2 ± 16.7, p = 0.06) and PRI-15 (24.4 ± 14.5 vs 18.9 ± 9.0, p = 0.04). A PRI-15 threshold of >35/h had specificity of 97 % for OSA., Conclusion: The PRI-15 shows promise as an indicator of OSA in children with normal oximetry.

Purpose: The aim of this study was to assess the impact of changes in respiratory support (RS) settings recommended after a titration polysomnography (PSG), in terms of daytime symptoms and quality of life., Methods: A retrospective chart review of all RS (CPAP and bi-level ventilation) titration studies was carried out at our tertiary paediatric sleep laboratory in the past 5 years. All patients with at least two studies in the past 5 years were included in the analysis. Parents completed the obstructive sleep apnoea (OSA)-18 and Paediatric Daytime Sleepiness Scale (PDSS) questionnaires on the night of each PSG. Results are presented as means (SD)., Results: A total of 42 patients (25 on CPAP and 17 on bi-level ventilation, age 11 (6) years) had 71 pairs of titration studies (41 CPAP and 30 bi-level). Changes in RS settings were recommended in 27 of 41 (65%) CPAP studies and 11 of 30 (36%) bi-level studies. Overall, changes were fully implemented by the treating physician in 55% of cases. There was an improvement in total OSA-18 score between studies in 48% of the paired CPAP studies and 65% of bi-level studies. OSA-18 scores improved in 47% of the studies where any recommended change had been implemented versus 0% of those where none of the recommended changes had been made (p=0.1)., Conclusions: Titration studies frequently led to recommendations for a change in RS settings in these patients on long-term RS. Symptom scores were more likely to improve if recommendations for change were implemented by the time of the follow-up study.

Study Objectives: In 2007 the American Academy of Sleep Medicine (AASM) published polysomnography (PSG) scoring guidelines, which were updated in 2012. A key change in terms of scoring respiratory events in children was the threshold for reduction in airflow (50% vs 30%) for the definition of hypopnea. This study aimed to determine the impact of different scoring rules on the assessment of severity of obstructive sleep apnea (OSA) in children., Methods: Forty-two children (mean age 4.3 y, 16 F) underwent PSG. An obstructive apnea-hypopnea index (OAHI) was determined using three scoring rules: (1) ATS 1996 rules with minor modifications (modified ATS 1996); (2) AASM 2007 rules (AASM 2007); and (3) AASM 2007 rules with respiratory event related arousals included in the OAHI (AASM+RERA)., Results: The AASM 2007 OAHI (median 0.4 events/h, range 0, 14) was lower than the modified ATS 1996 OAHI (median 0.8 range 0, 26.1, p < 0.001), underestimating severity of disease in 24% of cases. The AASM+RERA OAHI (median 0.8, range 0, 19.1) was also lower than the modified ATS 1996 OAHI (p = 0.02), but the difference was not clinically significant except at very high OAHIs., Conclusion: The AASM 2007 rules lead to a lower OAHI and lesser OSA severity when compared to the previous standard. Inclusion of RERAs in the AASM 2007 OAHI leads to a comparable OAHI to the previous rules. Given that morbidity has been demonstrated even in mild OSA, these results support the inclusion of events with a reduction in airflow of less than 50% as included in the updated AASM rules in 2012., (© 2014 American Academy of Sleep Medicine.)

Study Objectives: Although unattended ambulatory polysomnography (PSG) is frequently performed in adults, few studies have been performed in children. The objective of this study was to evaluate the feasibility of comprehensive, ambulatory PSG, including electroencephalography, in school-aged children in the home environment., Methods: A total of 201 children, born premature with birth weights of 500-1,250 grams, currently aged 5-12 years and living in Canada and Australia, underwent unattended ambulatory PSG., Results: PSG was initially technically satisfactory in 183 (91%) cases. Fourteen studies were satisfactory when repeated, resulting in an overall satisfactory rate of 197 (98%). Artifact-free signals were obtained for ≥ 75% of recording time in more than 92% of subjects, with the exception of nasal pressure, which was satisfactory for ≥ 75% of recording time in only 67% of subjects. However, thermistry signals were satisfactory for ≥ 75% of recording time in 92% of subjects, and some measure of airflow was present for ≥ 75% of recording time in 96% of subjects. Children slept very well, with a long total sleep time (534 ± 73 [mean ± SD] minutes), high sleep efficiency (92% ± 5%), and low arousal index (9 ± 3/h). Parents and children reported a high rate of satisfaction with the study., Conclusions: This large, international study has shown that comprehensive, unattended, ambulatory PSG is feasible, technically adequate and well-tolerated in school-aged children when performed under research conditions. Further studies regarding the cost efficacy of this approach, and generalizability of the findings to a clinical population, are warranted.

Purpose: The aim of this study was to assess the construct validity and clinical application of the Pediatric Sleep Survey Instrument (PSSI) as a tool to screen for sleep disordered breathing (SDB) in children., Methods: Polysomnography (PSG) outcomes and PSSI subscale scores were compared between a clinical cohort (N = 87, 5-10 years, 62 M/25 F) and a nonsnoring community sample (N = 55, 5-10 years, 28 M/27 F). Group comparisons assessed the ability of the PSSI subscales to discriminate between the clinical and community cohorts. Receiver operating characteristic (ROC) curves assessed construct validity, with the Apnea/Hypopnea Index (AHI) >5 events/h, OSA-18 score >60, and Pediatric Daytime Sleepiness Scale (PDSS) above the 70th percentile as the target references., Results: The clinical group had more respiratory events, respiratory-related arousals, fragmented sleep, and lower oxygen saturation nadir than the community group (p < 0.001 for all). PSSI subscale scores of Morning Tiredness, Night Arousals, SDB, and Restless Sleep were higher (p < 0.001 for all) in the clinical cohort, confirming the tool's ability to identify clinically relevant sleep problems. ROC curves confirmed the diagnostic accuracy of the SDB subscale against an AHI > 5 events/h (area under the curve (AUC) = 0.7), an OSA-18 score >60 (AUC = 0.7), and a PDSS score in the 70th percentile (AUC = 0.8). The Morning Tiredness subscale accurately predicted a PDSS score in the 70th percentile (AUC = 0.8). A cutoff score of 5 on the SDB subscale showed a sensitivity of 0.94 and a specificity of 0.76, correctly identifying 77 and 100 % of the clinical and community cohorts, respectively., Conclusion: The PSSI Sleep Disordered Breathing subscale is a valid tool for screening SDB and daytime sleepiness in children aged 5-10 years.

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.)

Purpose: Sleep disordered breathing (SDB) has adverse effects on cardiovascular health in adults, partly due to changes in autonomic activity. However, there have been limited studies in children. We analysed the impact of SDB and sleep stage on autonomic control of heart rate in 7-12-year-old children, utilizing spectral heart rate variability (HRV) as a measure of autonomic activity., Methods: Eighty children underwent overnight polysomnography. Subjects were grouped according to their obstructive apnoea-hypopnoea index (OAHI): controls, OAHI ≤1 event/h and no history of snoring; primary snorers (PS) OAHI ≤1, Mild (OAHI 1-5) and moderate/severe (MS) OAHI >5. HRV was analysed during Wake, nonrapid eye movement (NREM) 1&2, slow wave sleep (SWS) and REM., Results: Compared with controls, total power, low (LF) and high frequency (HF) power were reduced in all SDB severities during REM. LF/HF ratio was less in MS SDB (median = 0.34; range, 0.20-0.49; p < 0.05) versus controls (0.38; 0.26-0.55; p < 0.05) and PS (0.39; 0.23-0.57; p < 0.05) during SWS. In all groups, total power, LF and HF power were highest during NREM 1&2 while LF/HF ratio was lowest during SWS. Blood pressure was elevated in SDB in all sleep states., Conclusions: HRV was altered in 7-12-year-old children with SDB, which may signify an overall depression of autonomic tone, perhaps a consequence of their elevated blood pressure during sleep coupled with repeated exposure to SDB event-related cardiovascular disturbance. Further research is warranted to elucidate the long-term effects on the cardiovascular system of subjects exhibiting impaired HRV and elevated BP in childhood.

Aims: To examine sleep study findings in children with Prader-Willi syndrome (PWS) referred for polysomnography (PSG) before commencement of growth hormone (GH) and to evaluate the impact of sleep testing on treatment decisions., Methods: The sleep unit database was used to identify all cases over an 8-year period (2003-2011). Standard overnight PSG was performed in the sleep laboratory. Obstructive sleep apnoea (OSA) was defined by an obstructive apnoea-hypopnoea index >1/h. Age, symptoms of OSA, tonsillar size and body mass index (BMI) Z-score were obtained through chart review., Results: OSA was diagnosed in 15 of 34 (44%) cases identified. Those with OSA were significantly older (P = 0.009) and more likely to have enlarged tonsils (P = 0.05) than those without OSA. There was no difference in BMI Z-score or the presence of symptoms of OSA. GH was deferred in 13 (38%) pending treatment for OSA., Conclusions: OSA was frequently present in children with PWS referred simply to meet the requirement for PSG before starting GH. OSA was more likely in older children and those with enlarged tonsils. GH treatment was deferred in 38% of cases. This study supports routine performance of PSG prior to GH, regardless of clinical history., (© 2013 The Authors. Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians).)

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.)

Purpose: This study compared electroencephalogram (EEG) spectral analysis with standard visual scoring to assess the validity of clinical classification of arousals at respiratory event termination in children with obstructive sleep apnoea (OSA)., Methods: Twenty children (six M/14 F) aged 7-12 years, diagnosed with moderate to severe OSA participated in this study. Overnight polysomnography was performed, and sleep stages and arousals visually scored using clinical paediatric measures. The EEG was spectrally analysed in six 5-s epochs across respiratory events, namely two consecutive 5-s epochs pre-event onset and a 5s epoch post-event onset, 5-s before event termination, and two contiguous 5-s epochs post-event termination. EEG spectral power distribution was compared across respiratory events visually categorised as full cortical arousals, subcortical activations, or non-arousals using specialised software (Sleep Research System 5.0)., Results: There was no difference in power spectra between events in REM and NREM sleep and these were combined. There was a statistically significant fall from pre-arousal baseline values in delta and theta spectral power at respiratory event terminations associated with cortical arousals only. No change in power was detected at respiratory event terminations associated with subcortical activations or non-arousals., Conclusions: The lack of significant EEG spectral power changes at respiratory event terminations not associated with visually identified cortical arousals indicates undetected micro-arousals are not present. The results support the validity of clinical classifications of arousals at respiratory event termination.

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: To identify the extent of sleep disruption in children with various severities of sleep disordered breathing (SDB) using both conventional visually scored assessment of sleep stages and arousal indices together with EEG power spectral analysis., Design: Sleep stages and power spectral analysis of the sleep EEG in children with varying severities of SDB with matched control subjects with no history of snoring were compared across the whole night, across sequential hours from sleep onset, and across sleep stages., Measurements: Overnight polysomnography was performed on 90 children (49M/41F) aged 7-12 y with SDB and 30 age-matched healthy controls (13M/17F). Sleep stages were visually scored and the EEG spectra were analyzed in 5-s epochs., Results: Conventional visual scoring indicated that, although sleep duration was reduced in severely affected children, sleep quality during the essential stages of SWS and REM was preserved, as evidenced by the lack of any significant decrease in their duration in SDB severity groups. This finding was supported by the lack of substantial differences in EEG spectral power between the groups over the whole night, within specific hours, and in individual sleep stages., Conclusions: Both conventional scoring and EEG spectral analysis indicated only minor disruptions to sleep quality in children with SDB when assessed across the night, in any specific hour of the night, or in any specific sleep stage. These results suggest that reduced daytime functioning previously reported in children with SDB may not be due to sleep disruption. We speculate that in children, in contrast to adults, a stronger sleep drive may preserve sleep quality even in severe SDB.

Obstructive sleep apnoea (OSA) in children is commonly considered to occur predominantly in rapid eye movement (REM) sleep, but clinical experience suggests that this is not universally the case. We hypothesized that there would be a subgroup of children with OSA who have non-REM (NREM) predominance of obstructive events and that these children share certain clinical characteristics. Thus, we aimed to compare the obstructive apnoea-hypopnoea index (OAHI) in REM versus NREM sleep and to assess factors influencing the distribution of events by sleep state. Polysomnography (PSG) recordings of 102 children aged 0-18 years with moderate to severe OSA (OAHI >or=5 h(-1)) were reviewed. OAHI was calculated separately for REM and NREM sleep. A REM predominance index (RPI) was determined using log transformation [RPI = log (REM OAHI + 0.5) - log (NREM OAHI + 0.5)] and compared with possible influencing factors using multiple linear regression. Analysis showed that obstructive events were more common in REM sleep (median REM OAHI 21.4 h(-1), median NREM OAHI 8.3 h(-1), P < 0.001). Mean RPI was significantly greater than zero (P = 0.003). However, a substantial minority of children (30.4%) had a higher NREM than REM OAHI. The factors that were related significantly to NREM predominance were older age (P = 0.02), higher arousal index (P < 0.001) and higher SpO(2) nadir (P < 0.001). Our findings demonstrate that while OSA is a REM sleep-related problem in the majority of children, there is a significant subset of children with NREM predominance of obstructive events. This finding highlights the importance of considering sleep state distribution of events in studies of the pathophysiology and outcomes of OSA in childhood.

Aim: International guidelines recommend that children who are managed at home with mechanical respiratory support (RS) should have sleep studies performed every 6-12 months. This recommendation is based on expert opinion, with little evidence to support it. No studies have been undertaken to examine the utility of sleep studies in children on RS., Methods: A retrospective review of sleep studies performed over a 12-month period was undertaken at a New Zealand paediatric sleep medicine referral centre, to determine changes made to RS following sleep studies., Results: Sixty-one sleep studies were performed for assessment of RS in 45 children (27 boys; median age 8.3 years; range 0.4-18.6 years). Twenty-nine (64%) children were on continuous positive airway pressure, 14 (31%) on bi-level non-invasive ventilation, and two (4%) on tracheostomy ventilation. A change was made to RS settings after 66% of studies. No clinical parameters predicted which children would require a change in settings., Conclusions: Although sleep studies are expensive and time-consuming, follow-up studies of children on RS provide important information for optimising management into the long term.

Obstructive sleep apnoea (OSA) is a common condition of childhood with significant associated morbidity. The comprehensive evaluation of children who present with suggestive symptoms involves the overnight recording and assessment of both sleep and respiration by polysomnography in a sleep laboratory. These studies require resources and facilities that are not widely available and thus simpler, more available and less expensive alternatives have been sought. This review discusses the available alternatives to polysomnography for the evaluation of the child with suspected obstructive sleep apnoea.