Apert syndrome: the Paris and Rotterdam philosophy

Introduction: Apert syndrome is a rare type of syndromic craniosynostosis. Patients have an explicit phenotype with craniofacial dysmorphologies and severe symmetrical syndactyly of the hands and feet. This review includes background information about the syndrome and several aspects of the treatment. Areas covered: The cause of Apert syndrome is found in unique mutations in the Fibroblast Growth Factors Receptor (FGFR) 2 gene in 99%. It results in cranial suture fusion, craniofacial dysmorphologies and severe symmetrical syndactyly of the hands and feet. Patients with Apert syndrome are at risk for mental retardation, mobility impairment and intracranial hypertension (ICHT). This is the result of a complex interaction between (1) abnormal skull growth, (2) ventriculomegaly, (3) venous outflow obstruction and (4) obstructive sleep apnea (OSA). Mental retardation is mainly determined by the FGFR2 mutation and treatment is directed at protecting the intrinsic potential of neurocognition. Expert Opinion: To prevent ICHT, we prefer an occipital expansion in the first year of life. Screening on ICHT and its underlying causes is necessary at least until the age of ten by means of skull circumference measurements, fundoscopy, optical coherence tomography, MRI and polysomnography. Multicentre studies on long-term outcome are required to validate the rationale of different clinical protocols

Cortical Thickness in Crouzon-Pfeiffer Syndrome: Findings in Relation to Primary Cranial Vault Expansion

Background: Episodes of intracranial hypertension are associated with reductions in cerebral cortical thickness (CT) in syndromic craniosynostosis. Here we focus on Crouzon–Pfeiffer syndrome patients to measure CT and evaluate associations with type of primary cranial vault expansion and synostosis pattern. Methods: Records from 34 Crouzon–Pfeiffer patients were reviewed along with MRI data on CT and intracranial volume to examine associations. Patients were grouped according to initial cranial vault expansion (frontal/occipital). Data were analyzed by multiple linear regression controlled for age and brain volume to determine an association between global/lobar CT and vault expansion type. Synostosis pattern

Saethre–Chotzen syndrome: long-term outcome of a syndrome-specific management protocol

Aim: To assess the long-term outcomes of our management protocol for Saethre–Chotzen syndrome, which includes one-stage fronto-orbital advancement. Method: All patients born with Saethre–Chotzen syndrome between January 1992 and March 2017 were included. Evaluated parameters included occipital frontal head circumference (OFC), fundoscopy, neuroimaging (ventricular size, tonsillar position, a

Improvement in Sleep Architecture is associated with the Indication of Surgery in Syndromic Craniosynostosis

Background: Children with syndromic craniosynostosis (sCS) often suffer from obstructive sleep apnea (OSA) and intracranial hypertension (ICH). Both OSA and ICH might disrupt sleep architecture. However, it is unclear how surgically treating OSA or ICH affects sleep architecture. The aim of this study was twofold: to explore the usefulness of sleep architecture analysis in detecting disturbed sleep and to determine whether surgical treatment can improve it. Methods: Eighty-three children with sCS and 35 control subjects, who had undergone a polysomnography (PSG), were included. Linear-mixed models showed the effects of OSA and ICH on sleep architecture parameters. In a subset of 19 patients, linear regression models illustrated the effects of OSA-indicated and ICHindicated surgery on pre-to-postoperative changes. Results: An increase in obstructive-apnea/hypopnea index (oAHI) was significantly associated with an increase in N2-sleep, arousal index, and respiratoryarousal index and a decrease in REM-sleep, N3-sleep, sleep efficiency, and sleep quality. ICH and having sCS were not related to any change in sleep architecture. OSA-indicated surgery significantly increased the total sleep time and sleep efficiency and decreased the arousal index and respiratory-arousal index. ICHindicated surgery significantly decreased REM-sleep, N1-sleep, sleep efficiency, and sleep quality. Conclusions: For routine detection of disturbed sleep in individual subjects, PSGassessed sleep architecture is currently not useful. OSA does disrupt sleep architecture, but ICH does not. OSA-indicated surgery improves sleep architecture, which stresses the importance of treating OSA to assure adequate sleep. ICH-indicated surgery affects sleep architecture, although it is not clear whether this is a positive or negative effect

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,

The formation of the foramen magnum and its role in developing ventriculomegaly and Chiari I malformation in children with craniosynostosis syndromes

Object Craniosynostosis syndromes are characterized by prematurely fused skull sutures, however, less is known about skull base synchondroses. This study evaluates how foramen magnum (FM) size, and closure of its intra-occipital synchondroses (IOS) differ between patients with different craniosynostosis syndromes and control subjects; and whether this correlates to ventriculomegaly and/or Chiari malformation type I (CMI), intracranial disturbances often described in these patients. Methods Surface area and anterior-posterior (A-P) diameter were measured in 175 3D-CT scans of 113 craniosynostosis patients, and in 53 controls (0-10 years old). Scans were aligned in a 3D multiplane-platform. The frontal and occipital horn ratio was used as an indicator of ventricular volume, and the occurrence of CMI was recorded. Synchondroses were studied in scans with a slice thickness ≥1.25 mm. A generalized linear mixed model and a repeated measures ordinal logistic regression model were used to study differences. Results At birth, patients with craniosynostosis syndromes have a smaller FM than controls (p < 0.05). This is not related to the presence of CMI (p = 0.36). In Crouzon-Pfeiffer patients the anterior and posterior IOS fused prematurely (p < 0.01), and in Apert patients only the posterior IOS fused prematurely (p = 0.028). Conclusion The FM is smaller in patients with craniosynostosis syndromes than in controls, and is already smaller at birth. In addition to the timing of IOS closure, other factors may influence FM size

Brain and ventricular volume in patients with syndromic and complex craniosynostosis

Purpose: Brain abnormalities in patients with syndromic craniosynostosis can either be a direct result of the genetic defect or develop secondary to compression due to craniosynostosis, raised ICP or hydrocephalus. Today it is unknown whether children with syndromic craniosynostosis have normal brain volumes. The purpose of this study was to evaluate brain and ventricular volume measurements in patients with syndromic and complex craniosynostosis. This knowledge will improve our understanding of brain development and the origin of raised intracranial pressure in syndromic craniosynostosis. Methods: Brain and ventricular volumes were calculated from MRI scans of patients with craniosynostosis, 0.3 to 18.3 years of age. Brain volume was compared to age matched controls from the literature. All patient charts were reviewed to look for possible predictors of brain and ventricular volume. Results: Total brain volume in syndromic craniosynostosis equals that of normal controls, in the age range of 1 to 12 years. Brain growth occurred particularly in the first 5 years of age, after which it stabilized. Within the studied population, ventricular volume was significantly larger in Apert syndrome compared to all other syndromes and in patients with a Chiari I malformation. Conclusions: Patients with syndromic craniosynostosis have a normal total brain volume compared to normal controls. Increased ventricular volume is associated with Apert syndrome and Chiari I malformations, which is most commonly found in Crouzon syndrome. We advice screening of all patients with Apert and Crouzon syndrome for the development of enlarged ventricle volume and the presence of a Chiari I malformation

Foramen magnum size and involvement of its intraoccipital synchondroses in Crouzon syndrome

BACKGROUND: Cranial sutures and synchondroses tend to close prematurely in patients with Crouzon syndrome. This influences their skull vault and skull base development and may involve in common disturbances such as increased intracranial pressure and cerebellar tonsillar herniation. The authors' hypothesis was that Crouzon patients patients have a smaller foramen magnum than controls because of premature fusion of the intraoccipital synchondroses, putting them at risk for cerebellar tonsillar herniation. Therefore, foramen magnum size and time of intraoccipital synchondroses closure were evaluated and were related to the presence and degree of cerebellar tonsillar herniation. METHODS: The foramen magnum surface area and anteroposterior diameter were measured on three-dimensional computed tomographic scans of 27 Crouzon patients and 27 age-matched controls. Scans had a slice-thickness between 0.75 and 1.25 mm and were aligned in a three-dimensional reformatting platform. The t test was used to study size differences. Synchondroses were graded as described by Madeline and Elster and studied with ordinal logistic regression analysis. RESULTS: Crouzon patients had a smaller foramen magnum surface area (602 mm versus 767 mm, p < 0.001) and anteroposterior diameter (31 mm versus 35 mm, p < 0.001) compared with controls. Differences stayed constant over time. Intraoccipital synchondroses closed 3 to 9 months earlier in Crouzon patients than in controls (p < 0.05). CONCLUSIONS: Since intraoccipital synchondroses close earlier in Crouzon patients, from early life on their foramen magnum is smaller compared with controls. Within Crouzon patients, the presence of cerebellar tonsillar herniation could not be related to foramen magnum size. Copyrigh

First vault expansion in Apert and Crouzon-Pfeiffer syndromes: Front or back?

Background: Children with Apert and Crouzon-Pfeiffer syndromes are at risk of intracranial hypertension. Until 2005, when the authors switched to occipital expansion, their institution's preferred treatment was fronto-orbital advancement. However, it was still unclear whether (1) occipitofrontal head circumference (i.e., intracranial volume) was greater after occipital expansion than after fronto-orbital advancement; (2) the incidences of tonsillar herniation and papilledema were lower; and (3) visual acuity was better during follow-up. In these patients, the authors therefore compared fronto-orbital advancement with occipital expansion as the first surgical procedure. Methods: Measurements included repeated occipitofrontal head circumference as a measure for intracranial volume; neuroimaging to evaluate tonsillar herniation; funduscopy to identify papilledema; and visual acuity testing. Results: The authors included 37 patients (Apert syndrome, n = 18; Crouzon-Pfeiffer syndrome, n = 19). Eighteen underwent fronto-orbital advancement and 19 underwent occipital expansion (age at surgery, 1.0 versus 1.5 years; p = 0.13). Follow-up time in both groups was 5.7 years. The increase in occipitofrontal head circumference (+1.09 SD) was greater after occipital expansion than after fronto-orbital advancement (+0.32 SD) (p = 0.03). After occipital expansion, fewer patients with Crouzon-Pfeiffer syndrome had tonsillar herniation (occipital, three of 11; fronto-orbital advancement, seven of eight; p = 0.02); for both syndromes together, fewer patients had papilledema (occipital, four of 19; fronto-orbital advancement, 11 of 18; p = 0.02). Visual acuity was similar after fronto-orbital advancement and occipital expansion (0.09 versus 0.13 logarithm of the minimum angle of resolution) (p = 0.28). Conclusions: The authors' preference for occipital expansion as the initial craniofacial procedure in Apert and Crouzon-Pfeiffer syndromes is supported by the greater increase it produces in intracranial volume (as evidenced by the occipitofrontal head circumference), which reduces the incidences of tonsillar herniation and papilledema