Definition of diaphragmatic sleep disordered breathing and clinical meaning in Duchenne muscular dystrophy.

BACKGROUND: Diaphragmatic sleep disordered breathing (dSDB) has been recently identified as sleep dysfunction secondary to diaphragmatic weakness in Duchenne muscular dystrophy (DMD). However, scoring criteria for the identification of dSDB are missing.This study aimed to define and validate dSDB scoring criteria and to evaluate whether dSDB severity correlates with respiratory progression in DMD. METHODS: Scoring criteria for diaphragmatic apnoea (dA) and hypopnoeas (dH) have been defined by the authors considering the pattern observed on cardiorespiratory polygraphy (CR) and the dSDB pathophysiology.10 sleep professionals (physiologists, consultants) blinded to each other were involved in a two-round Delphi survey to rate each item of the proposed dSDB criteria (Likert scale 1-5) and to recognise dSDB among other SDB. The scorers' accuracy was tested against the authors' panel.Finally, CR previously conducted in DMD in clinical setting were rescored and diaphragmatic Apnoea-Hypopnoea Index (dAHI) was derived. Pulmonary function (forced vital capacity per cent of predicted, FVC%pred), overnight oxygen saturation (SpO2) and transcutaneous carbon dioxide (tcCO2) were correlated with dAHI. RESULTS: After the second round of Delphi, raters deemed each item of dA and dH criteria as relevant as 4 or 5. The agreement with the panel in recognising dSDB was 81%, kappa 0.71, sensitivity 77% and specificity 85%.32 CRs from DMD patients were reviewed. dSDB was previously scored as obstructive. The dAHI negatively correlated with FVC%pred (r=-0.4; p<0.05). The total number of dA correlated with mean overnight tcCO2 (r 0.4; p<0.05). CONCLUSIONS: dSDB is a newly defined sleep disorder that correlates with DMD progression. A prospective study to evaluate dSDB as a respiratory measure for DMD in clinical and research settings is planned.

Study protocol for a multicenter, multinational, observational registry of epidemiology, treatment and outcome of patients with Robin sequence.

BACKGROUND: Robin sequence (RS) is a congenital condition characterized by micrognathia, glossoptosis and upper airway obstruction. Diagnosis and treatment are characterized by heterogeneity, resulting in a lack of uniformly collected data. METHODS: We have set up a prospective, observational, multicenter, multinational registry aimed at obtaining routine clinical data from RS patients receiving different treatment approaches and enabling an assessment of outcomes obtained through different therapeutic approaches. Patient enrolment has started in January 2022. Disease characteristics, adverse events and complications depending on the different diagnostic and treatment approaches and their effects on neurocognition, growth, speech development and hearing outcome are evaluated using routine clinical data. In addition to characterizing the patient population and comparing outcomes achieved with different treatment approaches, the registry will evolve to focus on endpoints such as quality of life and long-term developmental status. DISCUSSION: This registry will provide data on different treatment approaches collected during routine care with diverse framework conditions and will allow assessing diagnostic and therapeutic outcomes of children with RS. These data, urgently demanded by the scientific community, may contribute to refining and personalizing existing therapeutic approaches and increase knowledge about the long-term outcome of children born with this rare condition. TRIAL REGISTRATION: DRKS00025365.

Respiratory Function and Sleep Disordered Breathing in Pediatric Duchenne Muscular Dystrophy.

BACKGROUND AND OBJECTIVES: The decline of respiratory function in Duchenne muscular dystrophy (DMD) is associated with sleep disordered breathing (SDB) and alteration of nocturnal gas exchange, first manifesting as nocturnal hypoventilation (NH). However, the correlation between the pulmonary function measured by spirometry (PFT) and the onset of SDB with or without NH is unclear. The aims of this study are to identify the prevalence and features of SDB and to investigate the relationship between lung function determined by forced vital capacity (FVC) and sleep abnormalities in a large pediatric DMD population. METHODS: This was a retrospective, single-center cohort study. FVC% predicted (FVC%) was calculated using predicted equations from the Global Lung Function Initiative. NH was defined by transcutaneous (tc) CO2 >50 mm Hg for >25% of total sleep time (TST), borderline NH by a mean tcCO2 between 45 and 50 mm Hg or tcCO2>50 mm Hg for ≤25% of TST, and clinically meaningful obstructive sleep apnea (OSA) by obstructive apnea-hypopnea index >5. The sensitivity, specificity, and positive and negative predictive values of FVC < 50% to indicate the presence of nocturnal hypoventilation were calculated. RESULTS: One hundred thirty-four patients underwent 284 sleep studies and 1222 PFT. The mean (SD) age at the first and the last sleep study was 12.9 (2.7) and 14.3 (2.6) years, respectively. Borderline NH (n = 31) was detected in both ambulant and early-nonambulant participants, while 100% of NH cases (n = 14) were nonambulant. NH was detected in 4 of the 14 patients despite an FVC >50%. Seventeen of the 26 patients with OSA presented with concomitant NH or borderline NH. FVC <50% was associated with NH indicating a sensitivity and specificity of 73% and 86%, respectively. Positive and negative predictive values were 32% and 97%, respectively. PFT showed a nonlinear, sudden FVC% decline in 18% of cases. DISCUSSION: FVC% <50 was associated with NH in close to a third of patients. CO2 elevation can be associated with obstructive/pseudo-obstructive events and was also observed in early nonambulant cases or in the presence of FVC >50%. These results are relevant for the clinical management of SDB.

Troponin-T type 1 (TNNT1)-related nemaline myopathy: unique respiratory phenotype and muscle pathology findings.

Biallelic pathogenic variants in the troponin T type 1 (TNNT1) gene cause a severe form of congenital nemaline myopathy. Typical features include severe motor delay, proximal contractures and weakness, pectus carinatum, chest wall rigidity and tremor. If left untreated, respiratory failure leads to early death at a median age of 18 months. Here we report on three non-Amish, unrelated patients harbouring novel TNNT1 variants. The peculiar combination of respiratory muscle weakness and chest wall stiffness caused early severe hypoventilation warranting the use of high pressures on BiPAP ventilator, with subsequent rapid escalation of pressures delivered with limited efficacy secondary to the extreme rib cage stiffness. Severe respiratory impairment occurred despite a relatively milder motor involvement in one patient. Muscle biopsies from two individuals showed predominant involvement of type 1 fibres, abundant nemaline bodies, marked fibrosis and loss of TNNT1 protein. We aim to increase the awareness of the challenges of managing respiratory support in patients with this unique respiratory phenotype.

Genotype-related respiratory progression in Duchenne muscular dystrophy-A multicenter international study.

INTRODUCTION/AIMS: Mutations amenable to skipping of specific exons have been associated with different motor progression in Duchenne muscular dystrophy (DMD). Less is known about their association with long-term respiratory function. In this study we investigated the features of respiratory progression in four DMD genotypes relevant in ongoing exon-skipping therapeutic strategies. METHODS: This was a retrospective longitudinal study including DMD children followed by the UK NorthStar Network and international AFM Network centers (May 2003 to October 2020). We included boys amenable to skip exons 44, 45, 51, or 53, who were older than 5 years of age and ambulant at first recorded visit. Subjects who were corticosteroid-naive or enrolled in interventional clinical trials were excluded. The progression of respiratory function (absolute forced vital capacity [FVC] and calculated as percent predicted [FVC%]) was compared across the four subgroups (skip44, skip45, skip51, skip53). RESULTS: We included 142 boys in the study. Mean (standard deviation) age at first visit was 8.6 (2.5) years. Median follow-up was 3 (range, 0.3-8.3) years. In skip45 and skip51, FVC% declined linearly from the first recorded visit. From the age of 9 years, FVC% declined linearly in all genotypes. Skip44 had the slowest (2.7%/year) and skip51 the fastest (5.9%/year) annual FVC% decline. The absolute FVC increased progressively in skip44, skip45, and skip51. In skip53, FVC started declining from 14 years of age. DISCUSSION: The progression of respiratory dysfunction follows different patterns for specific genotype categories. This information is valuable for prognosis and for the evaluation of exon-skipping therapies.

ERS statement on paediatric long-term noninvasive respiratory support.

Long-term noninvasive respiratory support, comprising continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV), in children is expanding worldwide, with increasing complexities of children being considered for this type of ventilator support and expanding indications such as palliative care. There have been improvements in equipment and interfaces. Despite growing experience, there are still gaps in a significant number of areas: there is a lack of validated criteria for CPAP/NIV initiation, optimal follow-up and monitoring; weaning and long-term benefits have not been evaluated. Therapeutic education of the caregivers and the patient is of paramount importance, as well as continuous support and assistance, in order to achieve optimal adherence. The preservation or improvement of the quality of life of the patient and caregivers should be a concern for all children treated with long-term CPAP/NIV. As NIV is a highly specialised treatment, patients are usually managed by an experienced paediatric multidisciplinary team. This statement written by experts in the field of paediatric long-term CPAP/NIV aims to emphasise the most recent scientific input and should open up new perspectives and research areas.

The role of the nasopharyngeal prong in craniofacial disorders in particular the Pierre Robin sequence.

There are a wide range of surgical and maxillofacial options to alleviate upper airway obstruction in children with craniofacial disorders. The nasopharyngeal prong (NPP) is a simple idea where the airway obstruction arising from the posteriorly placed tongue secondary to a small mandible can be overcome quickly and without resorting to more invasive surgical procedures. The role of the NPP is of particular interest in Robin sequence (RS). RS describes a congenital anomaly with retrognathia (often with associated U-shaped cleft palate) where in some children the tongue and small jaw can significantly impact on airway patency with upper airway obstruction. The NPP is a modified endotracheal tube, of ideal diameter and cut to a desired length that can bypass the airway obstruction and regain patency to the upper airway. RS has a natural history of mandibular growth and resolution of the symptoms with time and thus the NPP presents a medium term solution precluding the need in selected children of more permanent and potentially unnecessary surgical procedures. The role of the NPP in other craniofacial disorders (either as a temporary solution or longer term option) requires further research.

Managing infants with craniofacial malformations - Where to go next?

Treatment of infants with craniofacial malformations, e.g. Robin sequence, is characterized by considerable heterogeneity and a lack of randomized trials to identify an optimal approach. We propose to establish an international register using a common minimal dataset that will better allow for a comparison between key determinants and outcomes in these patients. In infants, this should include an assessment of mandibular micrognathia, glossoptosis, upper airway obstruction, weight gain and mode of feeding. Later on, neurocognition, speech development, hearing and quality of life should also be included. Together, these data will help better to advice parents on which treatment to choose for their baby with a craniofacial malformation.

Sleep Studies in Children.

Sleep-related breathing disorders (SRBD), also referred to as sleep-disordered breathing (SDB), are common sleep disorders in children. They can be broadly divided between central and obstructive sleep-disordered breathing with or without associated hypoventilation. In most cases, SRBD are associated with adenotonsillar hypertrophy (obstructive SDB) which are classified as simple. SRBD can co-exist with an underlying condition like obesity, genetic syndromes or neuromuscular disorders which are classified as complex. Polysomnography (PSG) is the gold standard for diagnosing sleep disorders. However, it is time-consuming and requires trained technician to acquire and interpret signals. Attended in-lab respiratory polygraphies are easier to conduct and provide respiratory data equivalent to a PSG. Similar to adult sleep services, overnight unattended home respiratory polygraphies are becoming more widely used. These require careful patient selection and good parental education programs to be most successful in children. Overnight oximetry has limitations but can be a useful tool for screening children with obstructive sleep apnea and prioritizing treatment. This review aims to discuss these various diagnostic methods to assess sleep disorders in children.

Selenoprotein N-related myopathy: a retrospective natural history study to guide clinical trials.

OBJECTIVE: To describe clinical features and disease progression of Selenoprotein N-related myopathy in a large multicenter cohort of patients. METHODS: Cross-sectional multicenter data analysis of 60 patients (53 families) with Selenoprotein N-related myopathy and single-center retrospective longitudinal analysis of 25 patients (21 families) over a median period of 5.3 years. RESULTS: The majority of patients (46/60, 77%) presented before age 2 years with hypotonia, poor head/neck control, and developmental delay. At last assessment (median age 14 years; range 2.5 to 36 years), 10/60 patients had minimal or no ambulation. Ventilatory support was initiated in 50/60 patients at a mean Forced Vital Capacity (FVC) of 38% and at a median age of 13 years. Forty-five/60 patients developed scoliosis (at median age 12.1 years) and 18 had scoliosis surgery at a median age of 13.6 years. Five children needed nasogastric feeds and/or gastrostomy. Longitudinal data analysis on 25 patients showed progressive decline of Hammersmith functional motor scores (estimated annual change -0.55 point), time to walk 10 meter, time standing from sitting, and from lying. Sixteen patients had weights < 2nd centile. The estimated change in FVC % per year was -2.04, with a 95% CI (-2.94, -1.14). CONCLUSIONS: This comprehensive analysis of patients with Selenoprotein N-related myopathy further describes the clinical course of this rare condition. The observed functional motor and respiratory data provide evidence of the slow decline patients experience over time which is useful when considering therapeutic intervention.

Cardiorespiratory Progression Over 5 Years and Role of Corticosteroids in Duchenne Muscular Dystrophy: A Single-Site Retrospective Longitudinal Study.

BACKGROUND: Corticosteroids (CSs) have prolonged survival and respiratory function in boys with Duchenne muscular dystrophy (DMD) when compared with CSs-naïve boys. RESEARCH QUESTION: The differential impact of frequently used CSs and their regimens on long-term (> 5 years) cardiorespiratory progression in children with DMD is unknown. STUDY DESIGN AND METHODS: This was a retrospective longitudinal study including children with DMD followed at Dubowitz Neuromuscular Centre, Great Ormond Street Hospital London, England, from May 2000 to June 2017. Patients enrolled in any interventional clinical trials were excluded. We collected patients' anthropometrics and respiratory (FVC, FVC % predicted and absolute FVC, and noninvasive ventilation requirement [NIV]) and cardiac (left ventricular shortening function [LVFS%]) function. CSs-naïve patients had never received CSs. Patients who were treated with CSs took either deflazacort or prednisolone, daily or intermittently (10 days on/10 days off) for > 1 month. Average longitudinal models were fitted for yearly respiratory (FVC % predicted) and cardiac (LVFS%) progression. A time-to-event analysis to FVC % predicted < 50%, NIV start, and cardiomyopathy (LVFS% < 28%) was performed in CS-treated (daily and intermittent) vs CS-naïve patients. RESULTS: There were 270 patients, with a mean age at baseline of 6.2 ± 2.3 years. The median follow-up time was 5.6 ± 3.5 years. At baseline, 263 patients were ambulant. Sixty-six patients were treated with CSs daily, 182 patients underwent CSs intermittent > 60% treatment, and 22 were CS-naïve patients. Yearly FVC % predicted declined similarly from 9 years (5.9% and 6.9% per year, respectively; P = .27) in the CSs-daily and CSs-intermittent groups. The CSs-daily group declined from a higher FVC % predicted than the CSs-intermittent group (P < .05), and both reached FVC % predicted < 50% and NIV requirement at a similar age, > 2 years later than the CS-naïve group. LVFS% declined by 0.53% per year in the CSs-treated group irrespective of the CSs regimen, significantly slower (P < .01) than the CSs-naïve group progressing by 1.17% per year. The age at cardiomyopathy was 16.6 years in the CSs-treated group (P < .05) irrespective of regimen and 13.9 years in the CSs-naïve group. INTERPRETATION: CSs irrespective of the regimen significantly improved respiratory function and delayed NIV requirement and cardiomyopathy.

Role of sleep study in children with Chiari malformation and sleep disordered breathing.

PURPOSE: Chiari malformation incorporate numerous forms of congenital or acquired cerebellar herniation through the foramen magnum. This may lead to brain stem, high spinal cord and cranial nerve compression resulting in obstructive and central apneas. This review highlights he high prevalence of sleep-disordered breathing in this population and the importance of refering these patients for sleep studies as part of their workup. METHODS: A review of the literature was performed through a PubMed and EMBASE search of original articles and reviews using the key words "chiari" "chiari malformation" "hindbrain herniation" "sleep disordered breathing" "obstructive sleep apnea" "central sleep apnea" "sleep study" and "foramen magnum decompression". DISCUSSION: We highlight the pathophysiology of sleep disordered breathing in patients with Chiari malformation, how it can be diagnosed and what the treatment options are. CONCLUSIONS: Sleep-disordered breathing is highly prevalent in patients with CM1. Clinicians caring for these patients should be aware of this and prioritise sleep diagnostic testing to allow for early diagnosis and management particularly in the presence of neurological symptoms and specific brain MRI pointers.

Screening for sleep-disordered breathing with Pediatric Sleep Questionnaire in children with underlying conditions.

The Pediatric Sleep Questionnaire described by Chervin et al. (Sleep Medicine, 2000, 1, 21-32) was originally validated for children with obstructive sleep apnoea syndrome but without other disorders. The aim of our study was to check the applicability of this questionnaire in children with underlying chronic medical conditions. Children aged 2-18 years who underwent a diagnostic sleep study at Great Ormond Street Hospital were recruited over a 10-month period. The Pediatric Sleep Questionnaire completed by their parents and cardiorespiratory polygraphy were scored. Sensitivities and specificities of the Pediatric Sleep Questionnaire were calculated using a Pediatric Sleep Questionnaire score of 0.33 as being indicative of sleep-disordered breathing. A total of 561 patients were reviewed. Neuromuscular disorders (n = 108), craniofacial anomalies (n = 58) and the obstructive sleep apnea syndrome control group (n = 155) were best represented. The sensitivity for patients with isolated obstructive sleep apnoea syndrome was 76.5% when using an apnoea-hypopnoea index ≥ 5, but this was much lower when looking at specific sub-groups such as neuromuscular patients (25%) or patients with Trisomy 21 (36.7%). Sensitivities remained unchanged for patients with obstructive sleep apnoea syndrome (77.3%) when an apnoea-hypopnoea index of ≥ 1 was used, but improved for neuromuscular disorders sub-groups (36.7%) and Trisomy 21 (84%). In conclusion, the Pediatric Sleep Questionnaire is not a good screening tool for obstructive sleep apnoea syndrome in children with complex underlying disorders when a cut-off apnoea-hypopnoea index of ≥ 5 is used, and it cannot replace cardiorespiratory polygraphy recording.

Hypoventilation disproportionate to OSAS severity in children with Prader-Willi syndrome.

OBJECTIVE: To test the hypothesis that children with Prader-Willi syndrome (PWS) and obstructive sleep apnoea syndrome (OSAS) have hypercapnia for higher proportion of total sleep time (TST) than non-syndromic children with similar obstructive apnoea-hypopnoea index (OAHI). DESIGN: Cross-sectional study. SETTING: Two tertiary care hospitals. PATIENTS: Patients with PWS and non-syndromic children with snoring who underwent polygraphy and were of similar age, body mass index (BMI) z-score and OAHI. MAIN OUTCOME MEASURE: The two groups were compared regarding %TST with transcutaneous CO2 (PtcCO2) >50 mm Hg. The interaction between PWS diagnosis and OSAS severity (OAHI <1 episode/h vs 1-5 episodes/h vs >5 episodes/h) regarding %TST with PtcCO2 >50 mm Hg was tested using multiple linear regression. RESULTS: 48 children with PWS and 92 controls were included (median age 2.3 (range 0.2-14.1) years vs 2.2 (0.3-15.1) years; BMI z-score 0.7±1.9 vs 0.8±1.7; median OAHI 0.5 (0-29.5) episodes/h vs 0.5 (0-33.9) episodes/h; p>0.05). The two groups did not differ in %TST with PtcCO2 >50 mm Hg (median 0% (0-100%) vs 0% (0-81.3%), respectively; p>0.05). However, the interaction between PWS and OSAS severity with respect to duration of hypoventilation was significant (p<0.01); the estimated mean differences of %TST with PtcCO2 >50 mm Hg between children with PWS and controls for OAHI <1 episode/h, 1-5 episodes/h and >5 episodes/h were +0.2%, +1% and +33%, respectively. CONCLUSION: Increasing severity of upper airway obstruction during sleep in children with PWS is accompanied by disproportionately longer periods of hypoventilation when compared with non-syndromic children with similar frequency of obstructive events.

The role of sleep diagnostics and non-invasive ventilation in children with spinal muscular atrophy.

Spinal muscular atrophy (SMA) is a degenerative motor neurone disorder causing progressive muscular weakness. Without assisted ventilation or novel therapies, most children with SMA type 1 die before the second year of life due to respiratory failure as the respiratory muscles and bulbar function are severely affected. Active respiratory treatment (mechanically assisted cough, invasive or non-invasive ventilation) has improved survival significantly in recent decades, but often at the cost of becoming ventilator dependent. The advent of a new oligonucleotide based therapy (Nusinersen) has created new optimism for improving motor function. However, the long-term effect on respiratory function is unclear and non-invasive respiratory support will remain an important part of medical management in patients with SMA. This review summarises the existing knowledge about sleep-disordered breathing and respiratory failure in patients with SMA, especially type 1, as well as the evidence of improved outcome and survival in patients treated with non-invasive or invasive ventilation. Practical considerations and ethical concerns are delineated with discussion on how these may be affected by the advent of new therapies such as Nusinersen.

Changing respiratory expectations with the new disease trajectory of nusinersen treated spinal muscular atrophy [SMA] type 1.

Spinal muscular atrophy [SMA] is the most common genetic cause of childhood mortality, primarily from the most severe form SMA type 1. It is a severe, progressive motor neurone disease, affecting the lower brainstem nuclei and the spinal cord. There is a graded level of severity with SMA children from a practical viewpoint described as "Non-sitters", "Sitters" and less commonly, "Ambulant" correlating with SMA Type 0/Type 1, Type 2 and Type 3 respectively. Children with SMA Type 0 have a severe neonatal form whilst those with SMA Type 1 develop hypoventilation, pulmonary aspiration, recurrent lower respiratory tract infections, dysphagia and failure to thrive before usually succumbing to respiratory failure and death before the age of 2 years. The recent introduction of the antisense oligonucleotide nusinersen into clinical practice in certain countries, following limited trials of less than two years duration, has altered the treatment landscape and improved the outlook considerably for SMN1 related SMA. Approximately 70% of infants appear to have a clinically significant response to nusinersen with improved motor function. It appears the earlier the treatment is initiated the better the response. There are other rarer genetic forms of SMA that are not treated with nusinersen. Clinical expectations will change although it is unclear as yet what the extent of response will mean in terms of screening initiatives [e.g., newborn screening], "preventative strategies" to maintain respiratory wellbeing, timing of introduction of respiratory supports, and prolonged life expectancy for the subcategory of children with treated SMA type 1. This article provides a review of the strategies available for supporting children with respiratory complications of SMA, with a particular emphasis on SMA Type 1.

ERS statement on obstructive sleep disordered breathing in 1- to 23-month-old children.

The present statement was produced by a European Respiratory Society Task Force to summarise the evidence and current practice on the diagnosis and management of obstructive sleep disordered breathing (SDB) in children aged 1-23 months. A systematic literature search was completed and 159 articles were summarised to answer clinically relevant questions. SDB is suspected when symptoms or abnormalities related to upper airway obstruction are identified. Morbidity (pulmonary hypertension, growth delay, behavioural problems) and coexisting conditions (feeding difficulties, recurrent otitis media) may be present. SDB severity is measured objectively, preferably by polysomnography, or alternatively polygraphy or nocturnal oximetry. Children with apparent upper airway obstruction during wakefulness, those with abnormal sleep study in combination with SDB symptoms (e.g. snoring) and/or conditions predisposing to SDB (e.g. mandibular hypoplasia) as well as children with SDB and complex conditions (e.g. Down syndrome, Prader-Willi syndrome) will benefit from treatment. Adenotonsillectomy and continuous positive airway pressure are the most frequently used treatment measures along with interventions targeting specific conditions (e.g. supraglottoplasty for laryngomalacia or nasopharyngeal airway for mandibular hypoplasia). Hence, obstructive SDB in children aged 1-23 months is a multifactorial disorder that requires objective assessment and treatment of all underlying abnormalities that contribute to upper airway obstruction during sleep.

Research Into Childhood Obstructive Sleep-Disordered Breathing: A Systematic Review.

BACKGROUND: Despite recent clinical guideline development, the best pathway of care for children with symptoms of obstructive sleep-disordered breathing (oSDB) is still debated. This systematic review aims to map the research in childhood oSDB that has been conducted so far to support further guideline development, identify evidence gaps, and guide future research. METHODS: A systematic search was performed in PubMed, EMBASE, and the Cochrane Library from inception to November 26, 2015. All publications on childhood oSDB were included, irrespective of type and language. The annual number of publications in the field of oSDB was counted over all years; for those published since January 1, 2011 (ie, the date of the latest literature search of the American Academy of Pediatrics guideline), total and annual numbers of publications across main research themes and methodologies were calculated. RESULTS: Of the 7,637 unique records retrieved, 5,871 publications were eligible for inclusion. There was an increase in annual publications since 2000, with 46% published since 2011. Most publications (61%) focused on individual treatment modalities, incidence, or prognosis. Few publications (2.7%) focused on health service delivery, outcomes, and health economics. Observational studies composed 78.5% of publications, 2.4% were randomized controlled trials, and 0.4% used a qualitative approach as their main methodology. CONCLUSIONS: A recent surge in research activity into childhood oSDB has improved the knowledge base for this condition; however, the lack of health services, health economics, and outcomes research impacts the applicability of evidence informing current guidance and leaves important questions for future research. REGISTRATION: PROSPERO: registration number CRD42015029291.