Does central sleep apnea occur in children with syndromic craniosynostosis?

Awake Hypercapnic Ventilatory Response in Obstructive Sleep Apnea Syndrome

Background and Objective Decreased ventilatory response to carbon dioxide or hypercapnic ventilatory response (HCVR) is a feature of pediatric obstructive sleep apnea (OSA) and is also known to diminish during sleep in obese adolescents (age, 12–16 years) with OSA. It reduces minute ventilation, air flow, and tidal volume during inspiration, as well as upper airway obstruction. The purpose of this study was to investigate awake HCVR in adult patients with OSA and to elucidate its association with sleep apnea.Methods HCVR was measured before performing polysomnography (PSG). PSG is performed as the evaluation method during sleep, and the severity of apnea is evaluated by apnea hypopnea index. Patient background, PSG data and HCVR were examined.Results Awake HCVR was greater in patients with severe OSA than in patients with mild and moderate OSA, and in severe OSA patients, the HCVR during awaking was higher in patients with larger changes in saturation of percutaneous oxygen during sleep. Awake HCVR did not differ by age, but it was greater in morbidly obese patients with OSA than in thin patients with OSA. The most frequent apnea pattern of OSA was obstructive, regardless of severity; although with an increasing severity of OSA, the central pattern decreased and the mixed pattern increased in frequency. The appearance of the mixed pattern increased in the augmented HCVR group.Conclusions This study suggested that awake HCVR could be used as an index of progression and a factor to determine the effects of treatment in patients with OSA.

Assessment of Central Sleep Apnea Events in Children with Sleep-Disordered Breathing

Purpose

To determine the prevalence of central apnea (CA) events and central sleep apnea (CSA) in children with sleep-disordered breathing (SDB) and to assess the effect of tonsillectomy and adenoidectomy (TA) on CSA in children with obstructive sleep apnea (OSA). Material and Methods. The medical charts of children with SDB were reviewed to obtain information on past medical history, polysomnography (PSG) findings, and surgical management. Counts and indexes of obstructive apnea, obstructive hypopnea, and central apnea were evaluated before and after TA. The prevalence of CSA and the effect of age, gender, obesity, and comorbid conditions on CSA were assessed in children with SDB as well as in children with PSG proven OSA.

Results

Seven hundred twelve children with SDB (age range: 1 to 18 yrs, mean: 5.8 ± 3.4) were identified. CA events occurred in 640 of 712 (89.5%) patients. Of the 712 patients, 315 (44.2%) met the criteria for the diagnosis of CSA. CSA was more prevalent in toddlers and preschoolers (p < 0.001). Obese children had a higher prevalence of CSA compared to nonobese children (p < 0.001). The prevalence of CSA in patients with OSA was 45.4%. The number of CA events, CAI, and OAHI after TA was less than that of before TA (p < 0.001). Residual CSA after TA occurred in 20 children (26%).

Conclusion

Central apnea events and central sleep apnea occur in children who present to a pediatric otolaryngology clinic for evaluation of sleep disordered breathing. Central sleep apnea and obstructive sleep apnea both improve after tonsillectomy and adenoidectomy.

Central apnea and periodic breathing in children with underlying conditions

Central sleep apneas and periodic breathing are poorly described in childhood. The aim of the study was to describe the prevalence and characteristics of central sleep apnea and periodic breathing in children with associated medical conditions, and the therapeutic management. We retrospectively reviewed all poly(somno)graphies with a central apnea index ≥ 5 events per hr in children aged > 1 month performed in a paediatric sleep laboratory over a 6‐year period. Clinical data and follow‐up poly(somno)graphies were gathered. Ninety‐five out of 2,981 patients (3%) presented central sleep apnea: 40% were < 1 year, 41% aged 1–6 years, and 19% aged ≥ 6 years. Chiari malformation was the most common diagnosis (13%). Mean central apnea index was 20 ± 30 events per hr (range 5–177). Fifty‐eight (61%) children had an exclusive central pattern with < 5 obstructive events per hr. Periodic breathing was present in 79 (83%) patients, with a mean percentage of time with periodic breathing of 9 ± 16%. Among periodic breathing episodes, 40% appeared after a sigh, 8% after an obstructive event, 6% after breathing instability and 2% after bradypnea. The highest clinical apnea index and percentage of time with periodic breathing were observed in children with encephalopathy and/or epilepsy (68 ± 63 events per hr and 30 ± 34%). Clinical apnea index did not differ according to age, while periodic breathing duration was longer in children > 1 year old. Watchful waiting was performed in 22 (23%) patients with spontaneous improvement in 20. Other treatments (upper airway or neurosurgery, nocturnal oxygen therapy, continuous positive airway pressure, non‐invasive ventilation) were effective in selected patients. Central sleep apnea is rare in children and comprises heterogeneous conditions. Sleep studies are essential for the diagnosis, characterization and management of central sleep apnea.

Cervical Spinal Cord Compression and Sleep-Disordered Breathing in Syndromic Craniosynostosis

BACKGROUND AND PURPOSE

Cerebellar tonsillar herniation arises frequently in syndromic craniosynostosis and causes central and obstructive apneas in other diseases through spinal cord compression. The purposes of this study were the following: 1) to determine the prevalence of cervical spinal cord compression in syndromic craniosynostosis, and 2) to evaluate its connection with sleep-disordered breathing.

MATERIALS AND METHODS

This was a cross-sectional study including patients with syndromic craniosynostosis who underwent MR imaging and polysomnography. Measures encompassed the compression ratio at the level of the odontoid process and foramen magnum and the cervicomedullary angle. MR imaging studies of controls were included. Linear mixed models were developed to compare patients with syndromic craniosynostosis with controls and to evaluate the association between obstructive and central sleep apneas and MR imaging parameters.

RESULTS

One hundred twenty-two MR imaging scans and polysomnographies in 89 patients were paired; 131 MR imaging scans in controls were included. The mean age at polysomnography was 5.7 years (range, 0.02-18.9 years). The compression ratio at the level of the odontoid process was comparable with that in controls; the compression ratio at the level of the foramen magnum was significantly higher in patients with Crouzon syndrome (+27.1, P < .001). The cervicomedullary angle was significantly smaller in Apert, Crouzon, and Saethre-Chotzen syndromes (-4.4°, P = .01; -10.2°, P < .001; -5.2°, P = .049). The compression ratios at the level of the odontoid process and the foramen magnum, the cervicomedullary angle, and age were not associated with obstructive apneas (P > .05). Only age was associated with central apneas (P = .02).

CONCLUSIONS

The prevalence of cervical spinal cord compression in syndromic craniosynostosis is low and is not correlated to sleep disturbances. However, considering the high prevalence of obstructive sleep apnea in syndromic craniosynostosis and the low prevalence of compression and central sleep apnea in our study, we would, nevertheless, recommend a polysomnography in case of compression on MR imaging studies.

Craniofacial syndromes and sleep-related breathing disorders

Children with craniofacial syndromes are at risk of sleep disordered breathing, the most common being obstructive sleep apnea. Midface hypoplasia in children with craniosynostosis and glossoptosis in children with Pierre Robin syndrome are well recognized risk factors, but the etiology is often multifactorial and many children have multilevel airway obstruction. We examine the published evidence and explore the current management strategies in these complex patients. Some treatment modalities are similar to those used in otherwise healthy children such as adenotonsillectomy, positive pressure ventilation and in the refractory cases, tracheostomy. However, there are some distinct approaches such as nasopharyngeal airways, tongue lip adhesion, mandibular distraction osteogenesis in children with Pierre Robin sequence, and midface advancement in children with craniosynostoses. Clinicians should have a low threshold for referral for evaluation of sleep-disordered-breathing in these patients.

Central sleep apnea in obese children with sleep-disordered breathing

OBJECTIVES

In contrast to obstructive sleep apnea (OSA), central sleep apnea (CSA) in obese children has received lesser attention. As pediatric CSA is more prevalent than expected and adversely impacts health, this study aims to elucidate the major factors associated with central apnea index (CAI) and compare CSA between obese and non-obese children.

METHODS

Retrospective analysis was performed in a tertiary referral medical center. Children with sleep-disordered breathing (SDB) ranging from 2-18 years old were enrolled. All participants completed history taking, otolaryngological examination and overnight polysomnography. CSA was defined as having CAI exceeding 1 h(-1). CAI and the prevalence of CSA were analyzed in children of different age groups, weight statuses and adenotonsillar sizes.

RESULTS

A total of 487 cases were included. The prevalence of CSA was 13.3% (65/487). CAI was negatively correlated with age (r=-0.32, P<0.001). Obese children had a significantly lower CAI than that of non-obese ones (0.20 ± 0.36 vs 0.48 ± 0.82 h(-1), P<0.001). Multiple linear regression analysis demonstrated a relationship between CAI, age and obesity as 'CAI=0.883-0.055 × Age -0.22 × (Obesity)'.

CONCLUSIONS

In children with SDB, younger ones have a significantly higher CAI than older ones. Additionally, obese children had a lower CAI than non-obese ones.

How does obstructive sleep apnoea evolve in syndromic craniosynostosis? A prospective cohort study

OBJECTIVE

To describe the course of obstructive sleep apnoea syndrome (OSAS) in children with syndromic craniosynostosis.

DESIGN

Prospective cohort study.

SETTING

Dutch Craniofacial Centre from January 2007 to January 2012.

PATIENTS

A total of 97 children with syndromic craniosynostosis underwent level III sleep study. Patients generally undergo cranial vault remodelling during their first year of life, but OSAS treatment only on indication.

MAIN OUTCOME MEASURES

Obstructive apnoea-hypopnoea index, the central apnoea index and haemoglobin oxygenation-desaturation index derived from consecutive sleep studies.

RESULTS

The overall prevalence of OSAS in syndromic craniosynostosis was 68% as defined by level III sleep study. Twenty-three patients were treated for OSAS. Longitudinal profiles were computed for 80 untreated patients using 241 sleep studies. A mixed effects model showed higher values for the patients with midface hypoplasia as compared to those without midface hypoplasia (Omnibus likelihood ratio test=7.9). In paired measurements, the obstructive apnoea-hypopnoea index (Z=-3.4) significantly decreased over time, especially in the first years of life (Z=-3.3), but not in patients with midface hypoplasia (Z=-1.5). No patient developed severe OSAS during follow-up if it was not yet diagnosed during the first sleep study.

CONCLUSIONS

OSAS is highly prevalent in syndromic craniosynostosis. There is some natural improvement, mainly during the first 3 years of life and least in children with Apert or Crouzon/Pfeiffer syndrome. In the absence of other co-morbid risk factors, it is highly unlikely that if severe OSAS is not present early in life it will develop during childhood. Ongoing clinical surveillance is of great importance and continuous monitoring for the development of other co-morbid risk factors for OSAS should be warranted.

Screening for symptoms of obstructive sleep apnea in children with severe craniofacial anomalies: assessment in a multidisciplinary unit

OBJECTIVE

To assess the incidence of airway obstruction symptoms and the presence of obstructive sleep apnea in children with severe craniofacial anomalies by a proactive screening program using a standard questionnaire and cardiorespiratory polygraphy.

PATIENTS AND METHODS

Children with severe craniofacial anomalies referred to our paediatric airway unit from February 2001 to June 2011 were eligible to be included in this retrospective, single centre study. Symptoms of airway obstruction were proactively investigated using the shorter version of the Pediatric Sleep Questionnaire (PSQ). Obstructive sleep apnea was assessed by means of cardiorespiratory polygraphy. Demographic data and reason for referral were also recorded. Primary outcomes were the prevalence of symptoms of airway obstruction and OSA.

RESULTS

44 children (24 girls) with severe craniofacial anomalies (15 Crouzon, 13 Apert, 9 Goldenhar, 5 Treacher-Collins, 2 Pfeiffer) were included, at a mean age of 5 years (range 8 months to 14 years). Reason for referral was routine follow up in 30 patients and overt OSA symptoms and signs in the remaining 14. PSQ results showed symptoms of airway obstruction in 82% of patients, being snoring the most frequent symptom (64.1%) followed by apneas (33.3%). Polygraphic studies showed inconclusive results in 8 children (18.2%), normal apnea-hypopnea index (AHI) in 16 (36.4%), mild obstructive sleep apnea in 9 (20.4%), moderate in 4 (9.1%) and severe obstructive sleep apnea in 7 (15.9%).

CONCLUSIONS

Children with craniofacial anomalies have a high prevalence of symptoms of airway obstruction and obstructive sleep apnea that support a proactive screening strategy in this highly selected population.