Accuracy of Detecting Obstructive Sleep Apnea Using Ambulatory Sleep Studies in Patients With Syndromic Craniosynostosis.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is seen in up to two-third of the patients with syndromic craniosynostosis. Gold standard to diagnose OSA is the hospital-based polysomnography, although alternatively ambulatory home sleep apnea devices are available. Aim of this study was to assess (1) accuracy of ambulatory sleep studies, (2) clinical decision making following sleep studies, and (3) course of OSA during long-term follow-up. MATERIALS AND METHODS: A retrospective cohort study was performed in children with syndromic craniosynostosis, of whom polysomnographies and home sleep apnea device recordings were collected. Measurements of apnea-hypopnea index, respiratory event index, total sleep/recording time, heart rate, oxygen saturation, and oxygen desaturation index were derived from the sleep studies. Primary clinical care subsequent to the sleep studies was determined using electronic patient files. RESULTS: In total, 123 patients were included, with 149 polysomnographies and 108 ambulatory studies. Performing an ambulatory study was associated with increased age at time of measurement (OR=1.1, 95% CI=1.02 to 1.17, P =0.01). No significant difference was found between the 2 types of sleep studies regarding sleep study parameters. Subsequent to sleep studies, patients with no-mild OSA had expectant care whereas patients with moderate-severe OSA underwent OSA-related treatment. OSA was most prevalent up to the age of 5 years, but also noticeable after the age of 10 years in patients with the Crouzon syndrome. CONCLUSIONS: Ambulatory sleep studies are reliable for diagnosing OSA in older children and can be used to determine clinical decision-making. Hence, we recommend implementing ambulatory sleep studies in a protocolized management.

Adult Saethre-Chotzen Syndrome: A Unique Abnormal Breathing Pattern.

ABSTRACT: A 35-year-old male with Saethre-Chotzen syndrome presented with severe complaints. Neuroimaging showed a Chiari-I malformation, mild ventriculomegaly, a syrinx of the wide central canal, and various cerebral vascular anomalies including a large occipital emissary vein on the right. Ultrasound of this vein confirmed blocking of the outflow-track when turning his head to the right, which also provoked the headaches and bruit. Polysomnography revealed severe positional sleep apnea with a mixed breathing pattern, the central components consisted of periodic breathing with, at times, crescendo-decrescendo reminiscent of a Cheyne-Stokes versus Biot breathing pattern, pointing to possible brain stem/pontine problems. Continuous positive airway pressure was initiated, and the patient was instructed to avoid sleeping in the right lateral position. One year later, nearly all his complaints have resolved. A questionnaire was sent to all adult Saethre-Chotzen patients in our craniofacial unit, none reported any of the severe symptoms as described by our index case.

Craniosynostosis affects the majority of mucopolysaccharidosis patients and can contribute to increased intracranial pressure.

BACKGROUND: The mucopolysaccharidoses are multisystem lysosomal storage diseases characterized by extensive skeletal deformities, including skull abnormalities. The objective of this study was to determine the incidence of craniosynostosis in the different mucopolysaccharidosis (MPS) types and its clinical consequences. METHODS: In a prospective cohort study spanning 10 years, skull imaging and clinical evaluations were performed in 47 MPS patients (type I, II, VI, and VII). A total of 215 radiographs of the skull were analyzed. The presence and type of craniosynostosis, the sutures involved, progression over time, skull shape, head circumference, fundoscopy, and ventriculoperitoneal shunt (VPS) placement data were evaluated. RESULTS: Craniosynostosis of at least one suture was present in 77% of all 47 MPS patients (≤ 6 years of age in 40% of all patients). In 32% of all MPS patients, premature closure of all sutures was seen (≤ 6 years of age in 13% of all patients). All patients with early closure had a more severe MPS phenotype, both in the neuronopathic (MPS I, II) and non-neuronopathic (MPS VI) patient groups. Because of symptomatic increased intracranial pressure (ICP), a VPS was placed in six patients, with craniosynostosis as a likely or certain causative factor for the increased pressure in four patients. One patient underwent cranial vault expansion because of severe craniosynostosis. CONCLUSIONS: Craniosynostosis occurs in the majority of MPS patients. Since the clinical consequences can be severe and surgical intervention is possible, skull growth and signs and symptoms of increased ICP should be monitored in both neuronopathic and non-neuronopathic patients with MPS.

Sleep Architecture Linked to Airway Obstruction and Intracranial Hypertension in Children with Syndromic Craniosynostosis.

BACKGROUND: Children with syndromic craniosynostosis often have obstructive sleep apnea and intracranial hypertension. The authors aimed to evaluate (1) sleep architecture, and determine whether this is influenced by the presence of obstructive sleep apnea and/or intracranial hypertension; and (2) the effect of treatment on sleep architecture. METHODS: This study included patients with syndromic craniosynostosis treated at a national referral center, undergoing screening for obstructive sleep apnea and intracranial hypertension. Obstructive sleep apnea was identified by polysomnography, and categorized into no, mild, moderate, or severe. Intracranial hypertension was identified by the presence of papilledema on funduscopy, supplemented by optical coherence tomography and/or intracranial pressure monitoring. Regarding sleep architecture, sleep was divided into rapid eye movement or non-rapid eye movement sleep; respiratory effort-related arousals and sleep efficiency were scored. RESULTS: The authors included 39 patients (median age, 5.9 years): 19 with neither obstructive sleep apnea nor intracranial hypertension, 11 with obstructive sleep apnea (four moderate/severe), six with intracranial hypertension, and three with obstructive sleep apnea and intracranial hypertension. Patients with syndromic craniosynostosis, independent of the presence of mild obstructive sleep apnea and/or intracranial hypertension, have normal sleep architecture compared with age-matched controls. Patients with moderate/severe obstructive sleep apnea have a higher respiratory effort-related arousal index (p < 0.01), lower sleep efficiency (p = 0.01), and less rapid eye movement sleep (p = 0.04). An improvement in sleep architecture was observed following monobloc surgery (n = 5; rapid eye movement sleep, 5.3 percent; p = 0.04). CONCLUSIONS: Children with syndromic craniosynostosis have in principle normal sleep architecture. However, moderate/severe obstructive sleep apnea does lead to disturbed sleep architecture, which fits within a framework of a unifying theory for obstructive sleep apnea, intracranial hypertension, and sleep. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

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.

Sleep apnoea in syndromic craniosynostosis occurs independent of hindbrain herniation.

PURPOSE: Hindbrain herniation (HH) is frequently found in syndromic craniosynostosis. It may cause impairment of the respiratory centres and manifest as sleep-disordered breathing. Our aim was to quantify sleep apnoea caused by HH in children with syndromic craniosynostosis. METHODS: Seventy-one children with syndromic and complex craniosynostosis (aged 0-18 years) underwent prospective magnetic resonance imaging and a sleep study. The position of the cerebellar tonsils and respiratory parameters were evaluated and analysed. None of the included patients had undergone previous foramen magnum decompression. RESULTS: HH was present in 35% of the patients and was more frequent in children with Crouzon syndrome (63%) than in other types of craniosynostosis (p = .018). There was a positive association between the position of the cerebellar tonsils and papilledema (p = .002). Sleep studies of children with craniosynostosis and HH were not different from those without HH. Obstructive sleep apnoea syndrome was not more prevalent in children with HH compared to those without HH (p = .12). A cluster analysis using indices of apnoea revealed that three new clusters between which age was significantly different (p = .025). CONCLUSION: Sleep apnoea in syndromic craniosynostosis is not caused by HH. Rather, our evidence suggests that sleep-disordered breathing in craniosynostosis may be caused by brain stem immaturity in young children or upper airway obstruction. Therefore, as long as the child remains asymptomatic, our preferred management of HH is to be conservative and provide regular neurosurgical follow-up.

Screening for obstructive sleep apnea in Treacher-Collins syndrome.

OBJECTIVES/HYPOTHESIS: This study evaluated the accuracy of established obstructive sleep apnea syndrome (OSAS) questionnaires based on presenting symptoms and complaints as screening tools for OSAS in Treacher-Collins syndrome (TCS). STUDY DESIGN: Cross-sectional cohort study. METHODS: In 35 TCS patients (13 children, 22 adults) in whom diagnostic polysomnographic results on OSAS were available, the Brouillette score was evaluated in children and the Epworth Sleepiness Scale in adults. RESULTS: The total Brouillette score showed a sensitivity of 50%, specificity of 71%, and positive and negative predictive values of 60% and 63%, respectively. The answer "No" to the question as to whether a child snored could rule out OSAS in children, and showed positive and negative predictive values of 55% and 100%, respectively. The Epworth Sleepiness Scale showed a sensitivity of 0%, specificity of 92%, and positive and negative predictive values of 0% and 57%, respectively. A positive answer to the question of whether a person falls asleep while sitting and talking to someone (sometimes or more) was able to predict OSAS in adults; this question had positive and negative predictive values of 100% and 72%, respectively. CONCLUSIONS: This cross-sectional cohort study showed that the Brouillette score and the Epworth Sleepiness Scale are of minimal usefulness in TCS. Diagnosis of OSAS based solely on complaints is not reliable, probably due to habituation. Therefore, for a good evaluation and optimal multidisciplinary treatment of this chronic disease in TCS, all newly referred pediatric and adult TCS patients should be screened for OSAS at least once with polysomnography.

A triage system for referrals of pediatric skull deformities.

The clinical pathways for craniosynostosis and nonsynostotic skull deformity are entirely different. At the Dutch Craniofacial Center (DCFC), all patients were assessed in the same multidisciplinary craniofacial clinic, a common practice in countries with developed health care. However, the high volume of referrals of nonsynostotic cases frequently resulted in the capacity of these clinics being exceeded, with some patients being assessed in the general pediatric plastic surgery clinic instead. In these general clinics, not all the multidisciplinary team members are routinely present, so patients with craniosynostosis had to make a second journey for further assessment, causing inconvenience, expense, and potential delay in treatment. With triage at the community level unreliable and triage at clinic level inefficient, we decided to trial a triage system to increase efficiency and to ensure patients enter the correct clinical pathway earlier.The 2 craniofacial secretaries were issued with a flowchart to be completed for each new referral. The flowcharts were designed to triage the patients into true craniosynostosis with an appointment for the multidisciplinary clinic or nonsynostotic deformity with an appointment with the craniofacial nurse practitioner (CNP). During a 3-month period, 107 referrals were made. The triage category listed on the initial flowchart for each patient was compared, with the final diagnosis made in the multidisciplinary and CNP clinics.None of the patients triaged as nonsynostotic deformity on the flowcharts were found to be true craniosynostosis after clinical assessment by the CNP. Radiographic assessment or assessment by the craniofacial surgeons in the DCFC confirmed this.The flowchart questionnaire used at the DCFC is a highly sensitive and therefore safe method for detecting craniosynostosis. It has helped to improve efficiency by ensuring patients are seen in an appropriate setting.