Geometric growth of the normal human craniocervical junction from 0 to 18 years old.

The craniocervical junction (CCJ) forms the bridge between the skull and the spine, a highly mobile group of joints that allows the mobility of the head in every direction. The CCJ plays a major role in protecting the inferior brainstem (bulb) and spinal cord, therefore also requiring some stability. Children are subjected to multiple constitutive or acquired diseases involving the CCJ: primary bone diseases such as in FGFR-related craniosynostoses or acquired conditions such as congenital torticollis, cervical spine luxation, and neurological disorders. To design efficient treatment plans, it is crucial to understand the relationship between abnormalities of the craniofacial region and abnormalities of the CCJ. This can be approached by the study of control and abnormal growth patterns. Here we report a model of normal skull base growth by compiling a collection of geometric models in control children. Focused analyses highlighted specific developmental patterns for each CCJ bone, emphasizing rapid growth during infancy, followed by varying rates of growth and maturation during childhood and adolescence until reaching stability by 18 years of age. The focus was on the closure patterns of synchondroses and sutures in the occipital bone, revealing distinct closure trajectories for the anterior intra-occipital synchondroses and the occipitomastoid suture. The findings, although based on a limited dataset, showcased specific age-related changes in width and closure percentages, providing valuable insights into growth dynamics within the first 2 years of life. Integration analyses revealed intricate relationships between skull and neck structures, emphasizing coordinated growth at different stages. Specific bone covariation patterns, as found between the first and second cervical vertebrae (C1 and C2), indicated synchronized morphological changes. Our results provide initial data for designing inclusive CCJ geometric models to predict normal and abnormal growth dynamics.

Diagnosis and treatment of Chiari malformation type 1 in children: the International Consensus Document.

BACKGROUND: Chiari malformation type 1 (CM1) is a rare condition where agreed classification and treatment are still missing. The goal of this study is to achieve a consensus on the diagnosis and treatment of CM1 in children. METHODS: A multidisciplinary panel formulated 57 provisional statements based on a review of the literature. Thirty-four international experts (IE) participated in a Delphi study by independently rating each statement on a 4-point Likert scale ("strongly disagree," "disagree," "agree," "strongly agree"). Statements that were endorsed ("agree" or "strongly agree") by < 75% of raters were re-formulated, or new statements were added, and another Delphi round followed (up to a maximum of three). RESULTS: Thirty-five IE were contacted and 34 agreed to participate. A consensus was reached on 30/57 statements (52.6%) after round 1. Three statements were added, and one removed. After round 2, agreement was reached on 56/59 statements (94.9%). Finally, after round 3, which took place during the 2019 Chiari Consensus Conference (Milan, Italy), agreement was reached on 58/59 statements (98.3%) about four main sections (Definition and Classification, Planning, Surgery, Isolated Syringomyelia). Only one statement did not gain a consensus, which is the "definition of radiological failure 24 month post-surgery." CONCLUSIONS: The consensus document consists of 58 statements (24 on diagnosis, 34 on treatment), serving clinicians and researchers following children with CM1. There is a clear need for establishing an international network and registry and to promote collaborative studies to increase the evidence base and optimize the long-term care of this patient population.

The utility of poly(somno)graphy in evaluating children with Chiari malformation type II before and after surgical intervention: a case series.

BACKGROUND: Children with Chiari Malformation type II (CM-II) have an increased risk of sleep apnoea. The aim of the study was to describe the management of patients with CM-II in relation to sleep apnoea syndrome, clinical symptoms and magnetic resonance imaging (MRI) findings. CASE SERIES PRESENTATION: The paper reports 8 consecutive patients with CM-II followed between September 2013 and April 2017. The prevalence of sleep apnoea syndrome was high with 6 out of 8 patients having mild-to-severe sleep apnoea. Patients with severe sleep apnoea syndrome (3 patients) were treated with upper airway surgery and/or noninvasive ventilation. CONCLUSION: Our findings highlight the importance of respiratory polygraphy in the management of patients with CM-ΙΙ. Poly(somno)graphy is recommended in the follow-up care of children with CM-II.

Forehead Widening in Nonsyndromic Scaphocephaly Operated After 12 Months of Age.

AIM AND SCOPE: Our standard management is to operate isolated sagittal synostosis around 4 months of age because of morphological and cognitive outcomes. However, some patients present late and the likelihood of spontaneous remodeling is low in isolated sagittal craniosynostosis operated on after 12 months of age with a limited technique. The preliminary result of a modified technique for forehead remodeling and subtotal calvarial remodeling in nonsyndromic scaphocephalic children with late presentation is presented. PATIENTS AND METHODS: All patients older than 1 with isolated sagittal synostosis assessed between 2011 and 2015, over 1 year of age at the time of surgery, with available pre and postoperative computed tomography-scans, were retrospectively included into the study. The following parameters were collected: (1) age at surgery, (2) duration of the procedure, (3) surgical technique, (4) fronto-nasal angle before and after surgery and (5) forehead width before and after surgery. RESULTS: Ten patients aged between 15 months and 6 years were retrospectively included. Delayed surgery was due to late presentation or initial parental reluctance. All patients presented with a transversal narrowing of the forehead and an anterior bulge. Mean age at surgery was 28 months and mean follow up was 23 months (1-4 years). Measurements showed significant improvement of both the fronto-nasal angle and the width of the forehead. CONCLUSIONS: Late-presenting scaphocephalic patients operated on after 12 months of age require forehead remodeling to achieve satisfactory aesthetic results. Modified forehead remodeling by splitting the forehead sagittally into 2 symmetrical halves and adding a midline bone strip is a safe and feasible way to widen the forehead. Long term follow-up is needed to assess this modified technique.

Strategy for Bone Conservation in the Two-Stage Correction of Hypertelorism in Craniofrontonasal Dysplasia.

Pre-emptive planning to optimize safety and outcome is a defining principle of pediatric craniofacial surgery, in which "procedures that come before" should enhance and not compromise procedures that are planned to follow.A technical modification of fronto-orbital advancement/remodeling in 2-stage hypertelorism surgery for craniofrontonasal dysplasia is presented, where orbital hypertelorism is accompanied by coronal craniosynostosis. Fronto-orbital advancement/remodeling undertaken by this approach preserves bone in the supero-lateral bandeau and provides optimal quality bone stock for the subsequent orbital box shift osteotomy. In this way the second procedure is protected and enhanced by optimal planning of the primary procedure, with potential benefits to safety, quality, and outcome of the final result.

Three Skulls Dating from the French Revolutionary Years Diagnosed with Tinea Capitis: A Paleopathologic Approach.

The Musée Dupuytren was a Parisian pathology museum established in 1835. This museum hosted 3 skulls with severe craniofacial lesions initially tagged as aggressive forms of tinea capitis. The aim of this study was to investigate these specimens and discuss the initial diagnosis. Historical investigations were conducted based on the biographic data from the tags of the 3 skulls and entries on the catalog of the museum. Age was determined using dentition and the patency of cranial base synchondroses. The computed tomography scans were performed using standard medical devices. The 3 skulls were from the late 18th to early 19th century. Skull № 1 was a 5-year-old child and presented with microcephaly and extensive vault osteolysis compatible with an aggressive benign lesion, a malignant tumor, or a chronic infection. Skull № 2 was a 12- to 18-year-old teenager and presented with symmetrical porotic hyperostosis compatible with undernutrition and various hematologic conditions causing prolonged anemia, but also with chronic inflammation and/or infection. Skull № 3 was also from a 12- to 18-year-old teenager and presented with focal temporal osteolysis compatible with an aggressive benign or a low-grade malignant temporal soft-tissue lesion or with chronic infection. These skulls contribute to the understanding of the concept of tinea in the 19th century. They are furthermore windows on the sanitary and social conditions in Paris in the years following the French revolution and during the Napoleonian wars.

Arachnoid cyst: a further anomaly associated with Kallmann syndrome?

BACKGROUND: Kallmann syndrome (KS) is defined by the association of hypogonadotropic hypogonadism and anosmia. It is characterized by a significant clinical and genetic heterogeneity; actually, it may present several non-reproductive non-olfactory anomalies, and all the ways of genetic transmission can be involved in the inheritance of the disease. Although six pathogenesis-related genes have been identified so far, KS remains sporadic in 70 % of the cases, and the genetic diagnosis is not available for all of them. The purpose of this paper is to present a further disease that can enrich the wide spectrum of KS variability, that is cerebral arachnoid cyst. CASE DESCRIPTION: This 11-year-old boy presented with the typical characteristics of KS together with those related to a sylvian arachnoid cyst. He was admitted because of worsening headache. At the admission, the physical examination revealed eunuchoid aspect, micropenis, previous cryptorchidism, and anosmia. MRI pointed out a large, left sylvian arachnoid cyst, agenesia of the olfactory bulbs/tracts complex, and hypoplasia of the left olfactory sulcus. The child was operated on by endoscopic fenestration of the cyst, followed by transient external drainage for subdural hygroma and microscopic fenestration for recurrence of the cyst. His statural growth is normal but the sexual development still delayed in spite of hormone replacement therapy. CONCLUSION: According to the present and the other four cases in the literature, arachnoid cyst should be included among the anomalies possibly accompanying KS date although this association seems to be occasional as far as embryogenesis and physiopathology are concerned.

Pediatric infratentorial ganglioglioma.

PURPOSE: Pediatric infratentorial gangliogliomas are exceedingly rare tumors; thus, the factors affecting their outcome are poorly understood and their optimal management has still to be defined. METHODS: We reviewed the literature on pediatric gangliogliomas with a focus on those located in the posterior fossa to study treatment and outcome data. We added to this review some of our clinical cases. RESULTS: We found 100 and 80 cases of brainstem and cerebellar pediatric ganglioglioma, respectively, in our literature review. The surgical management varied from biopsy to gross total resection, and adjuvant treatment was given after incomplete resection or at time of progression. A gross total resection should be attempted to remove the contrast enhancing part of the tumor, which may be possible in most of the cerebellar gangliogliomas and some of the brainstem lesions. The cervicomedullary ganglioglioma seems to be the most infiltrative and least amenable to complete resection. Chemotherapy has a limited role and BRAF mutation was reported in 38 to 54 % of cases. The use of radiotherapy exposes the patient to a risk of malignant transformation and should be reserved for unresectable tumors which progress. CONCLUSION: Pediatric posterior fossa gangliogliomas are rare and challenging tumors due to their frequent infiltrative component involving the brainstem. To date, adjuvant therapy has a limited role that may evolve with time thanks to the use of targeted therapies against BRAF mutation. The surgical resection of well-defined contrast enhancing parts should be attempted even in staged surgeries and balanced with the risks of neurological deterioration.

Distractor position and distraction amplitude in fronto-facial monobloc advancement : A case series.

Fronto-facial monobloc advancement with internal distraction (FFMBA) is a central procedure in the management of faciocraniosynostoses. In techniques with internal distraction, two sets of devices are generally positioned: bilateral fronto-orbital and temporo-zygomatic distractors, using a temporal tongue and groove osteotomy design. It is believed that distractors must be positioned as parallel as possible in the horizontal and sagittal planes to avoid mechanical conflicts between the sliding bone fragments of the tongue and groove during distraction, and thus optimize the advancement amplitude. Several approaches involving surgical planification and guides for distractor positioning have thus been proposed to monitor distractor placement. To explore the need for surgical planification in distractor placement, the parallelism of the position of the 4 distractors was assessed in 19 FFMBA procedures and we correlated a set of 10 distractor angles with the degree of advancement. We report that the horizontal cut of the tongue and groove can be used as a landmark for the positioning of the lower, temporo-zygomatic, distractor in fronto-facial monobloc advancement. Other parameters (relative position of the two homolateral and the two contralateral distractors and the orientations of the vertical and horizontal cuts of the tongue and groove) do not interfere with distraction, other things being equal. Our results indicate that distractor orientation is not a critical issue in fronto-facial monobloc advancement when devices are positioned as parallel as possible based on visual monitoring.

Frontal bone resorption after fronto-facial monobloc advancement in FGFR-related craniosynostoses: predictive factors.

BACKGROUND: Fronto-facial monobloc advancement with internal distraction (FFMBA) is a central procedure in the management of FGFR-related craniosynostoses. Children undergoing FFMBA may present with resorption of the frontal bony flap in the months or years following surgery. Here, we aimed at identifying the clinical factors associated with resorption and its extent in patients with Crouzon and Pfeiffer syndromes. METHODS: We conducted a retrospective monocentric study of children with Crouzon and Pfeiffer syndromes who underwent FFMBA between May 2008 and October 2021, with available CT-scan data (1) early after surgery before the initiation of distraction, (2) at the end of distraction, (3) 2 years after surgery and optionally (4) 5 years or more after surgery. The following parameters were included: sex, age, mutation, number of previous craniofacial procedures, presence of tracheostomy or ventriculo-peritoneal (VP) shunt, FFMBA indication (raised ICP, OSAS, exorbitism, morphology), per-operative parameters (use of osteosynthesis, per-operative advancement, duration of surgery) and post-operative parameters (CSF leak, infection, distraction initiation, total advancement, persistence of a retro-frontal dead space). RESULTS: 63 patients were included, with a mean age of 2.91 years (SD=1.61) at the time of surgery, male/female sex ratio of 1.1, and a majority of Crouzon syndrome (84%). Two years after surgery (average: 622 days, SD=286.7), mean frontal bone flap resorption was 4.83 cm2 ([0-27.3], SD=5.35). Factors associated with more severe frontal bone resorption were the intraoperative use of absorbable sutures vs steel wires (9.83 vs. 3.99, p=0.04) and the persistence of a retro-frontal dead space at 2 years after surgery (13.12 vs. 3.63, p<0.001). CONCLUSION: The use of absorbable sutures for frontal bone fixation in FFMBA and the persistence of a retro-frontal dead space two years after surgery are risk factors for bone resorption. This report indicates that rigid osteosynthesis should be favored, and both per-operative and early post-operative distractor activation should be performed with care and follow-up of brain expansion.

Optic nerve elongation during fronto-facial surgery for Crouzon syndrome: 3D quantification and clinical implications.

OBJECTIVE: Fronto-facial monobloc advancement with internal distraction (FFMBA) is a key procedure in the management of syndromic craniosynostoses. FFMBA involves circumferential dissection and linear enlargement of the orbit, potentially leading to mechanical stress on the optic nerve (ON). Several reports of transient vision loss during the distraction process led us to investigate ON shape modifications during facial advancement, with the aim to potentially refine current clinical guidelines on postoperative management and the distraction schedule. METHODS: Twenty-six patients with Crouzon syndrome were included in this study. ONs were segmented on pre- and postoperative CT scans. Distraction amplitudes, linear and curved lengths, and cross-section diameters of the ON were assessed along the main axis of the nerve. A two-level hierarchical multivariate linear model was used to screen for factors associated with ON morphology. RESULTS: The mean age at FFMBA was 4.4 ± 3.8 years. Two patients presented with transient impaired vision during distraction. The final mean fronto-orbital and temporo-zygomatic distraction amplitudes were 18 ± 4 mm and 18 ± 6 mm, respectively. At the end of distraction, ONs were elongated (+1.8 mm for curved lengths, p = 0.013), and their mean cross-section was reduced (-1.9 mm2, p < 0.001) in the proximal intraorbital portion (first 15 mm). In the 2 patients with visual symptoms, functional impairment was associated with ON area reduction (OR 0.487, p < 0.001) and increased temporo-zygomatic distraction amplitude (OR 2.240, p < 0.001). CONCLUSIONS: ON was elongated during FFMBA, with proximal diameter reduction. Transient visual impairment with normal fundus examination during distraction seemed to have a morphological basis, based on 2 cases. These results suggest the importance of vision monitoring associated with fundus examination during distraction, and advocate for early extubation after FFMBA to allow clinical follow-up.

Anatomy and mobility in the adult cadaveric craniocervical junction.

Genetic diseases with craniofacial malformations can be associated with anomalies of the craniocervical joint (CCJ). The functions of the CCJ are thus impaired, as mobility may be either limited by abnormal bone fusion causing headaches, or exaggerated in the case of hypermobility, which may cause irreparable damage to the spinal cord. Restoring the balance between mobility and stability requires surgical correction in children. The anatomy and biomechanics of the CCJ are quite unique, yet have been overlooked in the past decades. Pediatric evidence is so scarce, that investigating the adult CCJ is our best shot to disentangle the form-function relationships of this anatomical region. The motivation of the present study was to understand the morphological and functional basis of motion in the CCJ, in the hope to find morphological features accessible from medical imaging able to predict mobility. To do so, we have quantified the in-vitro kinematics of the CCJ in nine cadaveric asymptomatic adults, and estimated a wide range of mobility variables covering the complexity of spinal motion. We compared these variables with the shape of the occipital, the atlas and the axis, obtained using a dense geometric morphometric approach. Morphological joint congruence was also quantified. Our results suggest a strong relationship between bone shape and motion, with the overall geometry predicting best the primary movements, and the joint facets predicting best the secondary movements. We propose a functional hypothesis stating that the musculoligamental system determines movements of great amplitude, while the shape and congruence of joint facets determine the secondary and coupled movements, especially by varying the geometry of bone stops and the way ligaments are tensioned. We believe this work will provide valuable insights in understanding the biomechanics of the CCJ. Furthermore, it should help surgeons treating CCJ anomalies by enabling them to translate objectives of functional and clinical outcome into clear objectives of morphological outcome.

New diagnostic criteria for metopic ridges and trigonocephaly: a 3D geometric approach.

BACKGROUND: Trigonocephaly occurs due to the premature fusion of the metopic suture, leading to a triangular forehead and hypotelorism. This condition often requires surgical correction for morphological and functional indications. Metopic ridges also originate from premature metopic closure but are only associated with mid-frontal bulging; their surgical correction is rarely required. Differential diagnosis between these two conditions can be challenging, especially in minor trigonocephaly. METHODS: Two hundred seven scans of patients with trigonocephaly (90), metopic rigdes (27), and controls (90) were collected. Geometric morphometrics were used to quantify skull and orbital morphology as well as the interfrontal angle and the cephalic index. An innovative method was developed to automatically compute the frontal curvature along the metopic suture. Different machine-learning algorithms were tested to assess the predictive power of morphological data in terms of classification. RESULTS: We showed that control patients, trigonocephaly and metopic rigdes have distinctive skull and orbital shapes. The 3D frontal curvature enabled a clear discrimination between groups (sensitivity and specificity > 92%). Furthermore, we reached an accuracy of 100% in group discrimination when combining 6 univariate measures. CONCLUSION: Two diagnostic tools were proposed and demonstrated to be successful in assisting differential diagnosis for patients with trigonocephaly or metopic ridges. Further clinical assessments are required to validate the practical clinical relevance of these tools.

External lumbar drainage for the management of refractory intracranial hypertension in pediatric severe traumatic brain injury: a retrospective single-center case series.

OBJECTIVE: Guidelines for the management of pediatric severe traumatic brain injury (TBI) recommend external ventricular drainage for CSF drainage as a first-tier treatment in the intracranial pressure (ICP) pathway. However, ventriculostomy in children can sometimes be challenging because of the small size of the lateral ventricles. External lumbar drainage (ELD) may be a useful alternative; therefore, the authors analyzed the outcome of a cohort of pediatric patients who underwent ELD to manage intracranial hypertension (ICH). METHODS: This study retrospectively enrolled pediatric patients with ICH following severe TBI who underwent ELD. Radiological and clinical severity scores (Marshall classification, Rotterdam score, Injury Severity Score, and Pediatric Trauma Score) were noted. ICP and cerebral perfusion pressure (CPP) curves were analyzed 12 hours before and after the procedure. Any change in medical therapy was recorded, as well as the total volume and duration of drainage. Cerebellar tonsillar position according to the McRae line was noted before and after ELD. Glasgow Outcome Scale-Extended score at follow-up was also noted. RESULTS: Thirty patients were included, with a mean age of 8 ± 4.4 years, and a median admission Glasgow Coma Scale score of 7 ± 4 (range 3-13). ELD was performed after a median delay of 1 day (range 0-7 days), mean drainage volume/day was 296 ± 129 ml, and median duration of drainage was 7 ± 5 (range 2-12) days. Forty-three percent of the patients underwent ELD as a part of the first-tier therapy. ICP decreased after ELD (mean difference 13.4 ± 6.2 mm Hg, p < 0.001), whereas CPP increased (mean difference 10.6 ± 6.4 mm Hg, p < 0.001). Fifty-three percent of the cohort did not need any further second-tier therapy after ELD. The study found 1 case of drain revision and 3 cases of cerebellar tonsil herniation. CONCLUSIONS: These preliminary data suggest ELD is a valuable option to treat ICH in severely head-injured children, limiting the use of second-tier treatments. This pilot study should lay the foundation for a multicenter prospective trial.

AI-based diagnosis and phenotype - Genotype correlations in syndromic craniosynostoses.

Apert (AS), Crouzon (CS), Muenke (MS), Pfeiffer (PS), and Saethre Chotzen (SCS) are among the most frequently diagnosed syndromic craniosynostoses. The aims of this study were (1) to train an innovative model using artificial intelligence (AI)-based methods on two-dimensional facial frontal, lateral, and external ear photographs to assist diagnosis for syndromic craniosynostoses vs controls, and (2) to screen for genotype/phenotype correlations in AS, CS, and PS. We included retrospectively and prospectively, from 1979 to 2023, all frontal and lateral pictures of patients genetically diagnosed with AS, CS, MS, PS and SCS syndromes. After a deep learning-based preprocessing, we extracted geometric and textural features and used XGboost (eXtreme Gradient Boosting) to classify patients. The model was tested on an independent international validation set of genetically confirmed patients and non-syndromic controls. Between 1979 and 2023, we included 2228 frontal and lateral facial photographs corresponding to 541 patients. In all, 70.2% [0.593-0.797] (p < 0.001) of patients in the validation set were correctly diagnosed. Genotypes linked to a splice donor site of FGFR2 in Crouzon-Pfeiffer syndrome (CPS) caused a milder phenotype in CPS. Here we report a new method for the automatic detection of syndromic craniosynostoses using AI.

A European multicenter outcome study on the different perioperative airway management policies following midface surgery in syndromic craniosynostosis: a proposal for a Standard Operating Procedure.

BACKGROUND: Perioperative airway management following midface advancements in children with Apert and Crouzon/Pfeiffer syndrome can be challenging, and protocols often differ. This study examined airway management following midface advancements and postoperative respiratory complications. METHODS: A multicenter, retrospective cohort study was performed to obtain information about the timing of extubation, perioperative airway management, and respiratory complications after monobloc / le Fort III procedures. RESULTS: Ultimately, 275 patients (129 monobloc and 146 Le Fort III) were included; 62 received immediate extubation and 162 delayed extubation; 42 had long-term tracheostomies and nine perioperative short-term tracheostomies. Short-term tracheostomies were in most centers reserved for selected cases. Patients with delayed extubation remained intubated for three days (IQR 2 - 5). The rate of no or only oxygen support after extubation was comparable between patients with immediate and delayed extubation, 58/62 (94%) and 137/162 (85%) patients, respectively. However, patients with immediate extubation developed less postoperative pneumonia than those with delayed, 0/62 (0%) versus 24/161 (15%) (P = 0.001), respectively. Immediate extubation also appeared safe in moderate/severe OSA since 19/20 (95%) required either no or only oxygen support after extubation. The odds of developing intubation-related complications increased by 21% with every extra day of intubation. CONCLUSIONS: Immediate extubation following midface advancements was found to be a safe option, as it was not associated with respiratory insufficiency but did lead to fewer complications. Immediate extubation should be considered routine management in patients with no/mild OSA and should be the aim in moderate/severe OSA after careful assessment.

The Management of Hydrocephalus in Midline Posterior Fossa Cystic Collections: Surgical Outcome From a Retrospective Single-Center Case Series of 54 Consecutive Pediatric Patients.

BACKGROUND: Hydrocephalus frequently occurs with midline posterior fossa cystic collections. The classification of this heterogeneous group of developmental anomalies, including Dandy-Walker malformation, persisting Blake's pouch, retrocerebellar arachnoid cysts, and mega cisterna magna, is subject of debate. The absence of diagnostic criteria is confusing regarding the ideal management of PFCC-related hydrocephalus. OBJECTIVE: To decipher the surgical strategy for the treatment of children with PFCC-related hydrocephalus through a retrospective analysis of the surgical outcome driven by their clinical and radiological presentation. METHODS: This study enrolled patients operated of symptomatic PFCC-related hydrocephalus. Clinical and MRI features were examined, as well as the surgical outcome. Unbiased subgroup classification of the patients was performed with multiple component analysis as a function of imaging characteristics and hierarchical clustering on principal component. Outcome was assessed with binomial logistic regression and Kaplan-Meier analysis. RESULTS: Fifty-four patients were included between 2007 and 2021. Multiple component analysis suggested that cerebellar and vermian hypoplasia, vermian rotation, basal-tentorial angle, and fastigial angle were strongly correlated. Hierarchical clustering and the distribution of the patients in the bidimensional plot showed the clear segregation of 3 major clusters, which correlated with the radiological diagnosis ( P < .01). Binomial logistic regression and survival analysis showed that endoscopic third ventriculostomy was an effective treatment for patients with persisting Blake's pouch, while failing to control hydrocephalus in most of patients with Dandy-Walker malformation. CONCLUSION: Preoperative MRI in patients with PFCC-related hydrocephalus is essential to better define the diagnosis. The choice of treatment strategy notably relies on correct radiological diagnosis.

Mobility Assessment Using Multi-Positional MRI in Children with Cranio-Vertebral Junction Anomalies.

OBJECTIVE: This study aimed to assess the relevance of using multi-positional MRI (mMRI) to identify cranio-vertebral junction (CVJ) instability in pediatric patients with CVJ anomalies while determining objective mMRI criteria to detect this condition. MATERIAL AND METHODS: Data from children with CVJ anomalies who underwent a mMRI between 2017 and 2021 were retrospectively reviewed. Mobility assessment using mMRI involved: (1) morphometric analysis using hierarchical clustering on principal component analysis (HCPCA) to identify clusters of patients by considering their mobility similarities, assessed through delta (Δ) values of occipito-cervical parameters measured on mMRI; and (2) morphological analysis based on dynamic geometric CVJ models and analysis of displacement vectors between flexion and extension. Receiver operating characteristics (ROC) curves were generated for occipito-cervical parameters to establish instability cut-off values. (3) Additionally, an anatomical qualitative analysis of the CVJ was performed to identify morphological criteria of instability. RESULTS: Forty-seven patients with CVJ anomalies were included (26 females, 21 males; mean age: 10.2 years [3-18]). HCPCA identified 2 clusters: cluster №1 (stable patients, n = 39) and cluster №2 (unstable patients, n = 8). ΔpB-C2 (pB-C2 line delta) at ≥2.5 mm (AUC 0.98) and ΔBAI (Basion-axis Interval delta) ≥ 3 mm (AUC 0.97) predicted instability with 88% sensibility and 95% specificity and 88% sensitivity and 85% specificity, respectively. Geometric CVJ shape analysis differentiated patients along a continuum, from a low to a high CVJ motion that was characterized by a subluxation of C1 in the anterior direction. Qualitative analysis found correlations between instability and C2 anomalies, including fusions with C3 (body p = 0.032; posterior arch p = 0.045; inferior articular facets p = 0.012; lateral mass p = 0.029). CONCLUSIONS: We identified a cluster of pediatric patients with CVJ instability among a cohort of CVJ anomalies that were characterized by morphometric parameters with corresponding cut-off values that could serve as objective mMRI criteria. These findings warrant further validation through prospective case-control studies.

Predicting endoscopic third ventriculostomy success in pediatric shunt dysfunction: a monocentric retrospective case series of 70 consecutive children, systematic review, and meta-analysis.

OBJECTIVE: The outcome of endoscopic third ventriculostomy (ETV) in children who had previously received shunts and who were experiencing shunt dysfunction is still discussed in terms of efficacy (success rate from 40% to 80%) and safety (0%-32.5% of complications). Reported predictive factors of secondary ETV failure are age, early onset of hydrocephalus, and prematurity. The best surgical strategy in the different subgroups of patients with shunt dysfunction is still debated. Therefore, the authors aimed to identify subgroups of patients in whom shunt treatment was associated with favorable outcome of ETV, to define the role of ETV in patients with global rostral midbrain dysfunction syndrome. METHODS: This study was a monocentric retrospective case series and a meta-analysis of children who had previously received shunts and who underwent secondary ETV for shunt dysfunction between 2012 and 2022. Clinical and MRI features were examined, along with surgical outcome, etiology of hydrocephalus, and preoperative ETV Success Score. Univariate and multivariate analyses were performed to find predictors of outcome of secondary ETV. Youden's J index was calculated on age distribution to find an optimal age cutoff. Systematic review of the literature and a meta-analysis were performed according to the PRISMA statement. RESULTS: Seventy consecutive patients were included. The overall success rate of secondary ETV was 63%. Primary obstructive hydrocephalus, age ≥ 36 months, and the presence of aqueductal obstruction were predictors of ETV success. Multivariate analysis found that age < 36 months, primary inflammatory hydrocephalus, and presence of fourth ventricular obstruction were associated with ETV failure. All patients with global rostral midbrain dysfunction syndrome experienced clinical and radiological improvement after ETV. The meta-analysis showed that postinflammatory etiology and age < 36 months were predictors of ETV failure. CONCLUSIONS: ETV is safe and effective for children with obstructive hydrocephalus experiencing shunt dysfunction, notably in cases of primary obstructive hydrocephalus with aqueductal stenosis, and among children whose age was ≥ 36 months who had postinflammatory hydrocephalus.

Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement: A Three-Dimensional Quantification.

BACKGROUND: Crouzon syndrome is characterized by complex craniosynostosis and midfacial hypoplasia. Where frontofacial monobloc advancement (FFMBA) is indicated, the method of distraction used to achieve advancement holds an element of equipoise. This two-center retrospective cohort study quantifies the movements produced by internal or external distraction methods used for FFMBA. Using shape analysis, this study evaluates whether the different distraction forces cause plastic deformity of the frontofacial segment, producing distinct morphologic outcomes. METHODS: Patients with Crouzon syndrome who underwent FFMBA with internal distraction [Hôpital Necker-Enfants Malades (Paris, France)] or external distraction [Great Ormond Street Hospital for Children (London, United Kingdom)] were compared. Digital Imaging and Communications in Medicine files of preoperative and postoperative computed tomographic scans were converted to three-dimensional bone meshes and skeletal movements were assessed using nonrigid iterative closest point registration. Displacements were visualized using color maps and statistical analysis of the vectors was undertaken. RESULTS: Fifty-one patients met the strict inclusion criteria. Twenty-five underwent FFMBA with external distraction and 26 with internal distraction. External distraction provides a preferential midfacial advancement, whereas internal distractors produce a more positive movement at the lateral orbital rim. This confers good orbital protection but does not advance the central midface to the same extent. Vector analysis confirmed this to be statistically significant ( P < 0.01). CONCLUSIONS: Morphologic changes resulting from monobloc surgery differ depending on the distraction technique used. Although the relative merits of internal and external distraction still stand, it may be that external distraction is more suited to addressing the midfacial biconcavity seen in syndromic craniosynostosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.