Morphometric analysis of the supraorbital region for sexual dimorphism: A study on Brazilian adult dry skulls.

Introduction: Pelvis, long bones, and skull are good indicators of sexual dimorphism. In the skull, the supraorbital region is considered a highly sexually dimorphic part. Thus, the present study aimed to analyze the sexual dimorphism of Brazilian adult dry skulls using conventional and geometric morphometry. Materials and Methods: Conventional morphometry was performed on 179 skulls, through the analysis of six linear measurements. For geometric morphometry, 89 skulls (right side) were selected and seven landmarks were considered. Generalized procrustes analysis, principal component analysis, and linear discriminant analysis were then carried out. Results: All linear measurements presented differences between both sexes. Geometric morphometry showed that 77.05% of the sample variation could be explained by the first three principal components. Moreover, considering the centroid size, there was a difference in shape between the sexes. Geometric morphometry classified sex correctly in 77.32% of the skulls and conventional morphometry from 60.89% to 73.74%. Conclusions: According to the analyses, the supraorbital region presents significant sexual dimorphism in Brazilian adult dry skulls. Moreover, it can be analyzed efficiently by both conventional and geometric morphometry, although the latter seems to be slightly more accurate.

Revision Cranioplasty with Three-dimensional (3D) Custom-made Titanium Implants in patients with failed cranioplasty.

OBJECTIVE: Graft failure is a common complication of cranioplasty.Revision cranioplasty is required to overcome this complication. However, no previous studies have reported outcomes in revision cranioplasty with three-dimensional (3D) custom-made titanium implants. We described our experience with 3D titanium implants in patients with revision cranioplasty. METHODS: We evaluated 43 consecutive patients who underwent revision cranioplasty using 3D custom-made titanium implants between January 2011 and December 2019.The 3D image of the patient's cranium and the plan to close the cranium defect were created in a virtual environment using software programs. Demographic and radiological features were compared based on the materials used in the initial cranioplasty. RESULTS: Previous material was autologous graft (AG) in 27 patients and polymethyl methacrylate (PMMA) in 16 patients. The mean time without revision cranioplasty is longer in patients with PMMA implants than in patients with AG. There was no statistically significant difference in the length of hospital stay between patients with PMMA implants and patients with AG. There were no postoperative adverse events such as infection, wound dehiscence, convulsions, and epidural hematoma in 38 patients during hospitalization. Wound dehiscence developedin 5 patients and surgical repair was required in one. CONCLUSION: Initial cranioplasty with PMMA provides a longer time period than the AG before the revision. However, both of them have similar outcomes based on length of hospital stay and cranial defect area. Custom-made 3D titanium implant is a good option for revision cranioplasty to prevent implant failure and reduce patients' cosmetic concerns.

Cranioplasty using patient specific implants Polyether ether ketone versus ultra-high molecular weight polyethylene: A prospective study.

This prospective study aimed to compare ultra-high molecular weight polyethylene (UHMWPE) with polyetheretherketone (PEEK) in computer-designed patient-specific implants (PSIs) for cranial defect reconstruction, in terms of complications and aesthetic outcomes. Primary or secondary cranioplasty-eligible patients were included, while patients with active infection or hydrocephalus, or unfit for general anesthesia, were excluded from the study. All the implants were designed and fabricated by the same maxillofacial surgeon using CAD/CAM technology. UHMWPE PSIs were used in group 1 and PEEK PSIs in group 2. Technically, UHMWPE could be milled to a thinner margin thickness than PEEK, which resulted in better handling properties and a smoother end finish. All patients were evaluated over a period of 6 months in terms of overall complications or implant failure as the primary outcome, according to Clavien-Dindo (CVD) grading, and cosmetic satisfaction with the aesthetic results, using a Likert scale, as the secondary outcome. In total, 22 cranioplasty patients were included, with a mean age of 30.8 years (SD = 16.3). Across both groups, 17 patients (77.3%) did not develop postoperative complications. These occurred in three patients in group 1 (CVD grade I, II, and IIIb) (27.3%) and in two patients in group 2 (CVD grade II, IIIa, and IIIb) (18.2%), with no statistical difference (p = 0.6). None of the cases in both groups developed any clinical or radiographic signs of infection, or suffered implant failure. The mean satisfaction score was 4.8 in group 1 and 4.5 in group 2 (SD = 0.6). The difference in satisfaction scores between the two was not statistically significant (p = 0.23). Although UHMWPEE was comparable to PEEK in terms of overall complication rates and cosmesis after craniectomy, UHMWPEE as a material exhibited greater resiliency in technically challenging cases with large, complex/midline-crossing designs, previously fitted meshes, or single-stage resection-reconstruction, allowing better marginal adaptation.

Impact of extent of resection and adjuvant radiation therapy in the progression free survival in patients with spheno-orbital meningioma.

BACKGROUND: Spheno-orbital meningiomas (SOM) are known to invaded critical skull base areas. The authors report a series of WHO I SOM, propose a subclassification of this tumor according to its extension to critical positions and analyze the impact of extent of resection and the role of stereotactic radiotherapy in tumor recurrence. METHODS: A prospective maintained university medical center registry was utilized to undertake a retrospective review of patients operated with WHO I SOM. Details related to critical skull base region's extension (superior orbital fissure, cavernous sinus, orbital apex), extent of resection and adjuvant radiosurgery were collected. Statistical calculations were preformed using IBM SPSS Statistics version 25. A p value < 0.05 was considered significant. Survival analysis was performed using Kaplan-Meier survival analysis and the log rank test. RESULTS: A total of 77 patients operated from 2002 to 2021 were included. There were 65 women (84.4 %) and 12 men (15.6 %). Mean age at surgery was 54.8 years (median 53 years, range 23 - 88). Tumors were defined as local in 28 (35.4 %) and with extension into the skull base critical structures in 51 (64.6 %). GTR was achieved in 35 (44.3 %), STR in 40 (50.6 %), and PR in four (5.1 %). Surgical morbidity was 10 %. There was no surgical mortality. 28 patients with STR or PR were treated with adjuvant radiotherapy. The total length of follow up was a mean of 172.3 months. There were 14 recurrences/progressive growth (17.7 %), 63 patients (79.7 %) had no recurrence/progressive growth, and two patients (2.5 %) were lost to follow-up. PFS was significant statistically different in patients with invasive tumors in whom the extent of resection was subtotal, with a longer PFS in patients that were treated with adjuvant radiotherapy. (P value < 0.001). CONCLUSIONS: SOM could be divided in two groups according to its skull base extension facilitating decision management and outcome prediction. Patients with local WHO I SOM had higher rate of GTR and better PFS than tumors extending to involve critical regions. When STR or PR is achieved postoperative adjuvant radiotherapy is advised if there is evidence of previous tumor growth.

Clinical characteristics and therapeutic outcomes after endoscopic endonasal surgery for craniopharyngioma in the elderly.

OBJECTIVE: Craniopharyngiomas (CPs) in adults are rare benign epithelial tumors, and few contemporary studies have explored outcomes after surgical treatment in elderly patients, especially with regard to endoscopic endonasal surgery (EES). METHODS: A retrospective cohort study was conducted on patients aged ≥ 18 years with CP who were treated with EES from 2013 to 2022. The cohort was divided into nonelderly (18-64 years) and elderly (≥ 65 years) groups based on age. Various parameters, including patient and tumor characteristics, surgical outcomes, complications, and follow-up, were compared between the two age groups. RESULTS: A total of 193 patients met the inclusion criteria, with 161 (83.4%) patients in the nonelderly group and 32 (16.6%) patients in the elderly group. Preoperatively, older patients were more likely to have memory impairment (4.3% vs 18.8%, p = 0.010), fatigue or decreased energy (9.3% vs 34.4%, p = 0.001), hypopituitarism (68.7% vs 90.6%, p = 0.012), or hydrocephalus (18% vs 40.6%, p = 0.005), and they were more likely asymptomatic (1.2% vs 9.4%, p = 0.033) and less likely to experience headache (57.8% vs 31.3%, p = 0.006). Patients in the elderly group had a longer symptom duration (median [IQR] 5 [10] months vs 9.5 [13] months, p = 0.001) and higher comorbidity scores (p < 0.001). Postoperatively, gross-total resection was achieved in 145 (90.1%) and 28 (87.5%) patients in the nonelderly and elderly groups, respectively. Older patients were more likely to develop pneumonia (5% vs 21.9%, p = 0.004). There were no significant differences in the extent of resection (p = 0.541), pathological subtypes (88.2% vs 75.0% adamantinomatous, p = 0.089), operation time (mean ± SD 307.8 ± 68.3 minutes vs 323.5 ± 86.0 minutes, p = 0.257), estimated blood loss (median [IQR] 300 [200] ml vs 300 [238] ml, p = 0.594), length of stay (median [IQR] 15 [8] days vs 15 [22] days, p = 0.964), perioperative mortality (2.5% vs 3.1%, p > 0.99), or postoperative severe hypothalamic dysfunction (37.9% vs 50.0%, p = 0.237) between the groups. Multivariate Cox regression analysis demonstrated that tumor calcification (HR 3.406, 95% CI 1.859-27.233, p = 0.038) and preoperative hydrocephalus (HR 3.688, 95% CI 1.310-10.386, p = 0.013) were independently associated with decreased survival. The median follow-up period in the elderly group was shorter (71 months vs 44 months, p = 0.001), and no recurrence was observed (7.1% vs 0%, p = 0.132). CONCLUSIONS: This study demonstrates that EES is a viable treatment option for older CP patients. With appropriate perioperative management, EES does not significantly increase mortality and, in selected populations, is well tolerated by patients.

A novel technique for skull base reconstruction in craniofacial fibrous dysplasia surgery using three-dimensional printing and a dental alginate mold: illustrative case.

BACKGROUND: Fibrous dysplasia is a rare and benign skeletal lesion characterized by fibrous tissue proliferation due to an abnormal osteogenesis replacing normal bone. OBSERVATIONS: An 18-year-old male with fibrous dysplasia of the left sphenoid, ethmoid, orbit, and frontal bones was managed with excision and skull base reconstruction. After complete removal of the tumor, skull base reconstruction was commenced by making a reverse temporalis flap and placing it over the opened paranasal sinuses for a robust vascularized graft, followed by an abdominal fat graft, and then a pedicled pericranal flap was added to complete the multilayer onlay graft. To recreate the skull base, a mirror image of the contralateral skull base was constructed using three-dimensional (3D) printing, and the 3D-printed model was sterilized prior to the surgery. Intraoperatively, the model was then pressed onto dental alginate gel to make a negative mold. This was used to make the definitive flap using polymethylmethacrylate. Temporoplasty was also performed using polymethylmethacrylate to fill the defect left by the temporalis graft. The patient recovered well following the procedure. LESSONS: Appropriate, personalized skull base reconstruction techniques can be successfully done with 3D printing using alternative low-cost materials and implements, especially following resection of cases like craniofacial fibrous dysplasia. https://thejns.org/doi/10.3171/CASE24262.

Assessing The Feasibility of Selective Piezoelectric Osteotomy in Transorbital Approach to The Middle Cranial Fossa: Anatomical and Quantitative Study and Surgical Implications.

OBJECTIVES: To verify the feasibility and to discuss advantages and disadvantages of a piezoelectric orbitotomy (PO) during Superior Eyelid Endoscopic Transorbital Approach (SETOA). METHODS: Five adult specimens underwent exoscopic/endoscopic SETOA to middle cranial fossa. The surgical corridor was created via piezoelectric orbitotomy by performing three selective and safe micrometric bone cuts providing a one-piece trapezoid bone flap which was repositioned and secured at the end of procedure. A 3D scan of the bone flap allowed us to reconstruct a 3D model and calculate its volume. An illustrative case demonstrating the application of this novel technique was also presented. RESULTS: Anatomical-morphometric quantitative analysis showed a mean bony-volume gain of 1,574.26 mm3 by using PO. PO yielded concrete surgical advantages and theoretical benefits in terms of functional and esthetic outcomes. All osteotomies were micrometric clear-cut and precise, resulting in a very thin bony gap; a complete sparing of soft tissues and neurovascular structures in- and around the orbit was observed. Lateral orbital wall reconstruction by replacing the bone flap aims to mitigate the risk of enophthalmos, proptosis, CSF leakage, pseudomeningocele and pulsatile headache, which represent significant challenges in the relevant literature. CONCLUSION: PO may offer a viable, selective, effective, safe alternative to high-speed drilling during SETOA, especially for patients affected by intra-axial pathologies in which a watertight closure is mandatory. This procedure could prevent/decrease the risk of some of the main postoperative complications associated to the standard SETOA, resulting potentially in better functional and esthetic outcome.

Proton-Based Radiation Therapy for Skull Base Chondrosarcomas in Children and Adolescents: 40-year experience from a single institution.

BACKGROUND: The literature on skull base chondrosarcoma (CHS) is scarce. We report outcomes for pediatric and young patients ≤ 22 years with base of skull (BOS) CHSs treated with proton-based radiotherapy (PBRT). METHODS: We retrospectively reviewed all patients treated with PBRT between 1981 and 2023. Primary endpoints were overall survival (OS), chondrosarcoma-specific survival (CSS), progression-free survival (PFS), local control (LC), and distal control (DC). RESULTS: Eighty-four patients were identified. Median age at diagnosis was 19 years (range, 6 - 22). Most patients (n=79, 94%) had conventional CHS while 5 (6%) had mesenchymal CHS. Nine patients (11%) underwent gross total resection (GTR), 64 (76%) subtotal resection (STR) and 11 patients (13%) underwent biopsy. Twenty-four (29%) patients progressed prior to radiotherapy (RT). The median prescription dose was 70 Gy (RBE) (range, 50 - 79.7). At a median follow-up of 18.0 years [interquartile range (IQR),), 9.2 -26.2] from diagnosis, 11 patients recurred (7 local, 4 distant). Six patients died of disease. Five patients died of other causes. Ten-year OS, CSS and PFS rates for all patients were 93.3%, 94.7% and 88%, respectively. Twenty-year OS, CSS and PFS rates for conventional CHS (n=79) were 93.1%, 97.1% and 89.2%, respectively. Mesenchymal histology was significantly associated with worse OS and PFS. Pre-RT tumor progression portended worse OS and CSS. Eight patients (9.9 %) experienced a late toxicity grade 3 or greater. CONCLUSIONS: This is the largest cohort of pediatric BOS CHSs in literature to date. High-dose PBRT following surgical resection achieves excellent disease control with minimal toxicity.

Medicare Reimbursement and Utilization Trends Within Skull Base Surgery.

BACKGROUND: Medicare reimbursements for otolaryngology and neurosurgery procedures have generally declined since 2000. We explore Medicare reimbursement trends for anterior (ACF), middle (MCF), posterior cranial fossa (PCF), pituitary surgery (PS), and skull base reconstruction (SBR) surgery from 2000-2022. METHODS: Cross-sectional analysis of the Centers for Medicare and Medicaid Services (CMS) Physician Fee Schedule was performed from 2000-2022 on approach, resection, and repair of the skull base (CPTs 31290-31291, 61546, 61548, 61575-61619, 62165). Reimbursement data was adjusted for inflation to 2022 US dollars, and annual and total changes calculated. The CMS Part B National Summary Data File was analyzed for trends in Medicare procedure volume and total payment. RESULTS: Adjusted for inflation since 2000, reimbursements for ACF, MCF, PCF, PS, and SBR codes had an overall decrease of 22.85%, 32.43%, 28.09%, 44.22%, and 38.65%, respectively. Simultaneously, procedure volume increased at an average annual rate of 63.99%, 128.57%, 19.75%, 36.11%, and 12.79%, respectively. CONCLUSIONS: While nominal per-service Medicare reimbursement has increased for skull base surgery codes, there has been a downward trend in inflation-adjusted procedural reimbursement. This parallels findings in other otolaryngology and neurosurgery procedures. Despite this, surgical volume in all skull base surgery subfields has increased, indicating increased utility and adoption of these techniques.

Acute peritumoral brainstem hemorrhage of a clival chondrosarcoma successfully treated via endoscopic endonasal surgery: illustrative case.

BACKGROUND: Chondrosarcoma is typically a slow-growing tumor, and intratumoral hemorrhage is rare. Acute brainstem hemorrhage due to chondrosarcoma has rarely been reported. OBSERVATIONS: A 77-year-old man presented with the sudden onset of headache and vomiting followed by a declining level of consciousness, progressive right hemiparesis, and left ophthalmoplegia. Magnetic resonance imaging showed pontine hemorrhage and a mass in the retroclival space compressing the brainstem. Emergency endoscopic endonasal surgery was performed. Intraoperative observation revealed that a hematoma was located in the pons and subdural space around the tumor mass, suggesting that the hematoma had likely been caused by the rupture of small vessels around the pons, not by intratumoral hemorrhage. The pathological diagnosis was chondrosarcoma. The patient recovered well and underwent radiotherapy. LESSONS: This report describes a case of sudden neurological deterioration due to hemorrhage in a patient with chondrosarcoma of the skull base. An emergency endoscopic endonasal approach for mass reduction and hematoma removal was effective in the acute setting. This approach revealed the suspected etiology of peritumoral hemorrhage, not intratumoral hemorrhage. https://thejns.org/doi/10.3171/CASE2460.

Fluorescence guidance in skull base surgery: Applications and limitations - A systematic review.

Introduction: Intraoperative fluorescence guidance is a well-established surgical adjunct in high-grade glioma surgery. In contrast, the clinical use of such dyes and technology has been scarcely reported in skull base surgery. Research question: We aimed to systematically review the clinical applications of different fluorophores in both open and endonasal skull base surgery. Material and methods: We performed a systematic review and discussed the current literature on fluorescence guidance in skull base surgery. Results: After a comprehensive literature search, 77 articles on skull base fluorescence guidance were evaluated. A qualitative analysis of the articles is presented, discussing clinical indications and current controversies. The use of intrathecal fluorescein was the most frequently reported in the literature. Beyond that, 5-ALA and ICG were two other fluorescent dyes most extensively discussed, with some experimental fluorophore applications in skull base surgery. Discussion and conclusion: Intraoperative fluorescence imaging can serve as an adjunct technology in skull base surgery. The scope of initial indications of these fluorophores has expanded beyond malignant glioma resection alone. We discuss current use and controversies and present an extensive overview of additional indications for fluorescence imaging in skull base pathologies. Further quantitative studies will be needed in the future, focusing on tissue selectivity and time-dependency of the different fluorophores currently commercially available, as well as the development of new compounds to expand applications and facilitate skull base surgeries.

The Bony Nasal Cavity and Paranasal Sinuses of Big Felids and Domestic Cat: A Study Using Anatomical Techniques, Computed Tomographic Images Reconstructed in Maximum-Intensity Projection, Volume Rendering and 3D Printing Models.

This study aims to develop three-dimensional printing models of the bony nasal cavity and paranasal sinuses of big and domestic cats using reconstructed computed tomographic images. This work included an exhaustive study of the osseous nasal anatomy of the domestic cat carried out through dissections, bone trepanations and sectional anatomy. With the use of OsiriX viewer, the DICOM images were postprocessed to obtaining maximum-intensity projection and volume-rendering reconstructions, which allowed for the visualization of the nasal cavity structures and the paranasal sinuses, providing an improvement in the future anatomical studies and diagnosis of pathologies. DICOM images were also processed with AMIRA software to obtain three-dimensional images using semiautomatic segmentation application. These images were then exported using 3D Slicer software for three-dimensional printing. Molds were printed with the Stratasys 3D printer. In human medicine, three-dimensional printing is already of great importance in the clinical field; however, it has not yet been implemented in veterinary medicine and is a technique that will, in the future, in addition to facilitating the anatomical study and diagnosis of diseases, allow for the development of implants that will improve the treatment of pathologies and the survival of big felids.

Skull Base Osteomyelitis Due to Staphylococcus epidermidis in the Absence of Indwelling Medical Devices Presenting With Bilateral Internal Carotid Artery Thrombosis.

Skull base osteomyelitis (SBO) is a severe and uncommon infection that typically affects the skull base and may arise from undiagnosed otogenic or sinonasal infection. This case describes a rare presentation of SBO, accompanied by thrombosis of the bilateral internal carotid artery with neurological deficits in a resource-limited environment, illustrating diagnostic and management dilemmas. A male patient aged 40 years with poorly controlled type 2 diabetes presented with sudden onset loss of consciousness and worsening right-sided weakness. MRI studies revealed SBO with cerebral involvement with thrombosis in major cerebral arteries and multiple brain infarcts. After receiving broad-spectrum antibiotics and supportive care shortly after admission, the patient developed septic shock and died two days after admission. The fast course of the disease in this case shows how severe SBO and its complications may be, calling for early diagnosis and intensive management of SBO, especially in diabetic patients. The fact that Staphylococcus epidermidis was established as a causative agent of disease in the absence of artificial heart valves or joints, it is becoming clear that there is a need to increase awareness of such rare pathogens, and probably new strategies for handling such infections should be developed. Additional research is required to elucidate the precise role of the pathogen and refine treatment approaches, especially for low-resource healthcare systems.

Reconstruction of Anterior Skull Base After Cleaver Trauma: Combined Use of Fascia Lata and Middle Turbinate Flap in a Patient with Concha Bullosa.

This video article presents a 47-year-old male patient who presented to the emergency department after a cleaver bounced off the grinding wheel and lodged between his eyebrows. The patient complained of clear nasal drainage since the trauma. Computed tomography showed a comminuted displaced fracture starting from the right frontonasal recess and extending along the right ethmoid roof. The patient underwent surgery. The skull base defect was reconstructed with a free fascia lata graft in the first operation. In the second session, the reconstruction of the skull base was reinforced with a flap that was prepared from the middle turbinate with the concha bullosa. The patient was followed for eight months. The patient's symptoms resolved completely and there was no evidence of rhinorrhoea or any other complication at the control examination. No complications were seen on control magnetic resonance imaging.

Skink systematics inside out: Comparative cranial osteology of the New World Mabuyinae.

The Mabuyinae subfamily exhibits remarkable diversity, encompassing 26 genera and 236 currently recognized species. Traditionally, the entire range of the group was attributed to the single genus Mabuya, which had a wide distribution along tropical regions of the Planet. In recent studies, phylogenetic hypotheses based on molecular data have identified four major groups, which have been further divided into geographically distinct clades. At least two phylogenetically distinct lineages of Mabuyinae are distributed in the Neotropical Region: Trachylepis atlantica and the remaining 16 genera within the Mabuyinae clade from the mainland and the Caribbean islands. Our understanding of Mabuyinae osteology is still quite limited, particularly concerning interspecific variation. This lack of information hinders our ability to make strong contributions to the phylogenetic relationships within this group or even to confirm the existence of certain new taxa considering their relatively conserved external morphology. This work provides a comprehensive anatomical reference for the adult skull of Neotropical Mabuyinae lizards, highlighting osteological features that might be useful for delimiting each genus. This descriptive guide includes illustrations and employs multiple techniques, such as dry preparation, clearing and staining, and high-resolution computerized microtomography. Our results provide additional diagnostic characteristics that include specific cranial bone arrangements, dental patterns, and cranial adaptations, such as dorsoventral head flattening, and their functional implications for bite force and cranial biomechanics. This study reinforces the importance of cranial morphology in understanding the phylogenetic relationships and evolutionary trajectories of New World Mabuyinae lizards, advocating for broader morphological sampling to enrich our understanding of these diverse reptiles.

Exploring fluctuating asymmetry in two recovering populations of the Eurasian otter.

The Eurasian otter is a wide-ranging semi-aquatic mammal that underwent a significant population decline in the last century, leading to local extinctions, reduction and fragmentation of populations. The individuals of populations exposed to both external and internal stress may present the inability to produce a specific developmental outcome, generating developmental 'noise' (developmental instability (DI)). Factors contributing to DI include inbreeding depression, population bottlenecks, habitat loss and exposure to pollution. We analysed fluctuating asymmetry (FA) as a proxy of DI in two European otter populations that experienced a major decline in the 1990s. Using three-dimensional geometric morphometrics methods on skull samples of otters from the UK and Sweden, we compared the degree of FA both between populations before, during and after the decline. We found a higher FA in the UK populations compared with Sweden. The level of asymmetry differed significantly over time only in the UK population, where it was higher during the decline phase. FA in the UK populations can be attributed to the specific impact of polychlorinated biphenyls pollution that caused a bottleneck. More generally, our study suggests that habitat loss, pollution and limited gene flow may contribute to DI in declining otter populations, highlighting the need for continued investigation to identify and quantify the specific stressors behind this trend in local populations.

Mouse Brain Extractor: Brain segmentation of mouse MRI using global positional encoding and SwinUNETR.

In spite of the great progress that has been made towards automating brain extraction in human magnetic resonance imaging (MRI), challenges remain in the automation of this task for mouse models of brain disorders. Researchers often resort to editing brain segmentation results manually when automated methods fail to produce accurate delineations. However, manual corrections can be labor-intensive and introduce interrater variability. This motivated our development of a new deep-learning-based method for brain segmentation of mouse MRI, which we call Mouse Brain Extractor. We adapted the existing SwinUNETR architecture (Hatamizadeh et al., 2021) with the goal of making it more robust to scale variance. Our approach is to supply the network model with supplementary spatial information in the form of absolute positional encoding. We use a new scheme for positional encoding, which we call Global Positional Encoding (GPE). GPE is based on a shared coordinate frame that is relative to the entire input image. This differs from the positional encoding used in SwinUNETR, which solely employs relative pairwise image patch positions. GPE also differs from the conventional absolute positional encoding approach, which encodes position relative to a subimage rather than the entire image. We trained and tested our method on a heterogeneous dataset of N=223 mouse MRI, for which we generated a corresponding set of manually-edited brain masks. These data were acquired previously in other studies using several different scanners and imaging protocols and included in vivo and ex vivo images of mice with heterogeneous brain structure due to different genotypes, strains, diseases, ages, and sexes. We evaluated our method's results against those of seven existing rodent brain extraction methods and two state-of-the art deep-learning approaches, nnU-Net (Isensee et al., 2018) and SwinUNETR. Overall, our proposed method achieved average Dice scores on the order of 0.98 and average HD95 measures on the order of 100 µm when compared to the manually-labeled brain masks. In statistical analyses, our method significantly outperformed the conventional approaches and performed as well as or significantly better than the nnU-Net and SwinUNETR methods. These results suggest that Global Positional Encoding provides additional contextual information that enables our Mouse Brain Extractor to perform competitively on datasets containing multiple resolutions.

[Role of cranioplasty in the management of decompressive craniectomies: Study of the Adolphe de Rothschild Foundation Hospital cohort over 7 years]. / Place de la cranioplastie dans la prise en charge des crâniectomies décompressives : étude de la cohorte de l'Hôpital Fondation Adolphe de Rothschild sur 7 ans.

OBJECTIVES: The objective of our study is to take stock of the cranioplasty implants used within our establishment. MATERIALS AND METHOD: We analyzed the patients files who underwent craniectomy followed by cranioplasty between 2017 and 2023, with at least 1 year of follow-up after cranioplasty (n=75). The data were extracted from the computerized patient file (DxCare®, Dédalus) and the pharmaceutical management tool for drugs and sterile medical devices (Pharma®, Computer Engineering). The sex ratio, indication for craniectomy, operating time, time between craniectomy and cranioplasty, complications and aesthetic result were statistically analyzed. RESULTS: The main indications are stroke (n=59; 78.5%) and aneurysms (n=7; 9.5%). Among the 75 patients, 52 benefited from the placement of a custom implant (PolyEtherEtherCetone/PEEK or Hydroxyapatite) and 23 from cementoplasty. The operating time was significantly shorter (P<0.05) for custom cranioplasty (1.93±0.61h vs. 1.62±0.53). Only 4 patients (5.3%) were not satisfied with the aesthetic result following the placement of a custom implant. A greater risk of infection was found in the context of cementoplasty (43% for cementoplasties vs. 25% for the custom implant, so χ2 (P=0.1095), this difference not being statistically significant. CONCLUSION: This collaborative work between the pharmacy and the adult neurosurgery department served to establish an initial register for monitoring patients who have undergone cranioplasty for whom the ideal implant remains to be determined.

Glioblastoma induces the recruitment and differentiation of dendritic-like "hybrid" neutrophils from skull bone marrow.

Tumor-associated neutrophil (TAN) effects on glioblastoma (GBM) biology remain under-characterized. We show here that neutrophils with dendritic features-including morphological complexity, expression of antigen presentation genes, and the ability to process exogenous peptide and stimulate major histocompatibility complex (MHC)II-dependent T cell activation-accumulate intratumorally and suppress tumor growth in vivo. Trajectory analysis of patient TAN scRNA-seq identifies this "hybrid" dendritic-neutrophil phenotype as a polarization state that is distinct from canonical cytotoxic TANs, and which differentiates from local precursors. These hybrid-inducible immature neutrophils-which we identified in patient and murine glioblastomas-arise not from circulation, but from local skull marrow. Through labeled skull flap transplantation and targeted ablation, we characterize calvarial marrow as a contributor of antitumoral myeloid antigen-presenting cells (APCs), including TANs, which elicit T cell cytotoxicity and memory. As such, agents augmenting neutrophil egress from skull marrow-such as intracalvarial AMD3100, whose survival-prolonging effect in GBM we report-present therapeutic potential.