Assessment of cranial reconstruction utilizing various implant materials: finite element study.

The human head can sometimes experience impact loads that result in skull fractures or other injuries, leading to the need for a craniectomy. Cranioplasty is a procedure that involves replacing the removed portion with either autologous bone or alloplastic material. While titanium has traditionally been the preferred material for cranial implants due to its excellent properties and biocompatibility, its limitations have prompted the search for alternative materials. This research aimed to explore alternative materials to titanium for cranial implants in order to address the limitations of titanium implants and improve the performance of the cranioplasty process. A 3D model of a defective skull was reconstructed with a cranial implant, and the implant was simulated using various stiff and soft materials (such as alumina, zirconia, hydroxyapatite, zirconia-reinforced PMMA, and PMMA) as alternatives to titanium under 2000N impact forces. Alumina and zirconia implants were found to reduce stresses and strains on the skull and brain compared to titanium implants. However, PMMA implants showed potential for causing skull damage under current loading conditions. Additionally, PMMA and hydroxyapatite implants were prone to fracture. Despite these findings, none of the implants exceeded the limits for tensile and compressive stresses and strains on the brain. Zirconia-reinforced PMMA implants were also shown to reduce stresses and strains on the skull and brain compared to PMMA implants. Alumina and zirconia show promise as alternatives to titanium for the production of cranial implants. The use of alternative implant materials to titanium has the potential to enhance the success of cranial reconstruction by overcoming the limitations associated with titanium implants.

Current dilemma and future directions over prophylactic cranial irradiation in SCLC: a systematic review in MRI and immunotherapy era.

Small cell lung cancer (SCLC) is the most malignant pathological type of lung cancer with the highest mortality, and the incidence of brain metastasis (BM) is in high frequency. So far, prophylactic cranial irradiation (PCI) has been suggested as an effective treatment for preventing brain metastasis of SCLC. PCI has long been applied to limited-stage SCLC (LS-SCLC) patients who have achieved complete remission after radiotherapy and chemotherapy as a standard treatment. However, the neurocognitive decline is a major concern surrounding PCI. New therapeutic approaches targeting PCI-induced neurotoxicity, including hippocampal protection or memantine, have been increasingly incorporated into the therapeutic interventions of PCI. Helical tomotherapy, RapidArc, and Volumetric-modulated arc therapy (VMAT) with a head-tilting baseplate are recommended for hippocampal protection. Besides, in the MRI and immunotherapy era, the significance of PCI in SCLC patients is controversial. SCLC patients with PCI should be recruited in clinical trials since this is the only way to improve the existing standard of care. This review summarizes the current therapeutic strategy and dilemma over PCI for SCLC, providing a theoretical basis for clinical decision-making and suggestions for PCI practice in clinical.

Cranial Nerve Injuries Post Carotid Endarterectomy: A 15-Year Prospective Study with Routine Otolaryngologist and Neurological Evaluation.

OBJECTIVE: The aim of this prospective monocentric cohort study was to analyse the risk of otolaryngologist-assessed cranial nerve injuries (CNIs) following carotid endarterectomy (CEA) in our academic centre during a 15-year period, and to identify possible risk factors for CNI development. METHODS: From January 2007 to December 2022, 3749 consecutive CEAs were performed and their data prospectively recorded in a dedicated database. Cranial nerve injuries were assessed and defined according to a standardized protocol. Instrumental ear, nose and throat (ENT) evaluations were conducted within 30 days before intervention and before discharge. Preoperative neurological assessments were carried out in all patients with symptomatic carotid stenosis, while postoperative neurological evaluations were performed in all patients. Patients with newly onset cranial nerve injuries underwent follow-up assessments at 30 days and, if necessary, at 6, 12 and 24 months. Perioperative results, including mortality, major central neurological events, and postoperative CNIs, were analyzed. Regression or persistence of lesions during follow-up visits was assessed, and multivariate analysis (binary logistic regression) was conducted to evaluate clinical, anatomical, and surgical technique factors influencing the occurrence of CNIs. RESULTS: CEAs were performed more frequently in male patients (2453 interventions, 65.5%) than in females (1296 interventions, 34.5%). The interventions were performed in asymptomatic patients in 3078 cases (82%). In 66 cases the interventions followed a previous ipsilateral CEA. At preoperative ENT evaluation, no cases of ipsilateral pre-existent CNI were recorded. The 30-day stroke and death rate was 1%. In 113 patients (3%) a postoperative neck bleeding requiring surgical revision and drainage was noted. Pre-discharge ENT evaluations identified 259 motor cranial nerve injuries, accounting for 6.9% of the entire study group. Eighteen patients had lesions in more than one cranial nerve. ENT and neurological evaluations at 30 days showed the complete resolution of 161 lesions, whereas in 98 (2.6%) cases the CNI persisted. At one year, the rate of persistent CNI was 0.4% (10 patients), whereas at two years it was 0.25% (six cases), in all but one asymptomatic. At multivariate analysis, urgent intervention in unstable patients, secondary intervention, a clamping time >40 min., a hematoma requiring revision and a postoperative stroke were independent predictors of CNI. CONCLUSIONS: Data from this prospective monocentric cohort study showed that the occurrence of CNI following CEA was low, even when an independent multi-specialist evaluation was performed. The percentage of persistent lesions at two years was negligible and in most cases asymptomatic.

Rostral cranial fossa and sinonasal neoplasms with cribriform plate involvement in 32 dogs and 17 cats.

The rostral cranial fossa (RCF) consists of the sphenoid and ethmoid bones, which accommodate the olfactory bulbs and nerves along the recesses of the cribriform plate. Neoplasms located in the vicinities of the RCF can compress and/or invade the cribriform plate. Here we describe the clinical and pathologic findings of neoplasms involving the cribriform plate in 32 dogs and 17 cats autopsied over a 13-y period. The average ages of affected dogs and cats were 9.2 y and 9.7 y, respectively. No sex or breed predisposition was evident in dogs, but 13 of 18 cats were spayed females and 14 of 18 were domestic shorthair cats. The main clinical signs were seizures (10 cases) and epistaxis (5 cases) in dogs, and red-to-brown nasal discharge (5 cases) and seizures (4 cases) in cats. In dogs, the 22 sinonasal neoplasms included adenocarcinoma (14 cases), transitional carcinoma (4), squamous cell carcinoma (2), lymphoma (1), and histiocytic sarcoma (1); the 10 intracranial neoplasms consisted of high-grade gliomas (3 cases), psammomatous meningiomas (2), histiocytic sarcomas (2), olfactory neuroblastomas (2), and a meningeal granular cell tumor (1). In cats, the 14 sinonasal neoplasms included lymphoma (8 cases), adenocarcinoma (4), adenosquamous carcinoma (1), and squamous cell carcinoma (1); the 3 intracranial neoplasms consisted of oligodendroglioma (1), transitional meningioma (1), and olfactory neuroblastoma (1).

Practice of neurosurgery on Saturn.

BACKGROUND: The practice of neurosurgery on Saturn is almost identical to the one practiced on Earth. Because the art of practice of Medicine was transferred by homo sapiens sapiens "exearthed" 30 years ago from Earth to Saturn. METHODS: In this paper, we present three neurosurgical cases and provided management of them on Saturn. RESULTS: In two cases, the patients underwent surgery; in one case, the surgical indication was not established. CONCLUSION: These cases give us the means of reflection to improve the practice of Neurosurgery.

SIADH as a Rare Complication of Foramen Magnum Stenosis in an Infant With Achondroplasia.

Achondroplasia is the most common skeletal dysplasia and is associated with serious complications such as foramen magnum stenosis (FMS). This case report describes an infant with achondroplasia who presented with a syndrome of inappropriate antidiuretic hormone secretion (SIADH), secondary to significant FMS and myelocompression. A 2-month-old boy with prenatally diagnosed achondroplasia was referred due to disordered breathing and altered consciousness. On admission, apathy, hypotonus, and hypothermia with typical features of achondroplasia were noticed. Laboratory investigations revealed severe hyponatremia and hypochloridaemia with normal glucose and urea levels. The diagnosis of SIADH was made based on low serum osmolality in the presence of high urine osmolality, along with an elevated copeptin level. An emergency computerized tomography showed a high-grade stenosis at the cranio-cervical junction; subsequent magnetic resonance imaging demonstrated myelocompression. The patient underwent decompression surgery the next day; serum osmolality increased after the operation. Spontaneous breathing after extubation was sufficient whereas tetraplegia persisted despite intensive physiotherapy. Clinicians should be aware of SIADH as a presenting sign of FMS in children with achondroplasia. Further discussion is warranted regarding improving parental education and timing of screening recommendations.

Does the Angulation of the Screws in the Zero-P Implant Affect the Clinical and Radiological Outcomes of Patients?

OBJECTIVE: When implanting the Zero-P device, the screws of Zero-P form a bone wedge with a 40 ± 5° cranial and caudal angle (CCA). However, no study has been performed in the optimal CCA of the Zero-P implant. To investigate whether the cranial/caudal angles (CCA) of the screws affect the clinical and radiological outcomes in patients undergoing ACDF with the Zero-P implant. METHODS: From January 2016 to December 2023, we retrospectively analyzed 186 patients who underwent 1-level ACDF with the Zero-P device. The patients were divided into four groups: group A (cranial angle ≤40°, caudal angle ≤40°); group B (cranial angle ≤40°, caudal angle >40°); group C (cranial angle >40°, caudal angle ≤40°); and group D (cranial angle >40°, caudal angle >40°). The clinical outcomes, including Japanese Orthopaedic Association (JOA), neck disability index (NDI), and visual analogue scale (VAS) scores, the radiological parameters, including cervical lordosis (CL), cervical lordosis of operated segments (OPCL), intervertebral space height (ISH) and fusion rate (FR), and the complications, were evaluated and compared. Parametric tests, non-parametric tests, and chi-square tests were conducted to analyze the data. RESULTS: The OPCL of group A was significantly less than that of the other groups at the final follow-up (p < 0.05). The ISH of group D was significantly less than that of group A at the final follow-up (p < 0.05). The subsidence rate of group A was significantly less than that of group D at the final follow-up (p < 0.05). At the final follow-up, the upper adjacent-level degeneration (ASD) of group D was significantly less severe than that of groups A and B (p < 0.05). The clinical outcomes do not differ among groups (p > 0.05). CONCLUSION: A larger CCA of the screws (cranial angle >40°, caudal angle >40°) was better for maintaining OPCL and reducing the incidence of ASD. A smaller CCA of the screws (cranial angle ≤40°, caudal angle ≤40°) was better for maintaining ISH and reducing the rate of subsidence.

Not All Patients with a Headache need a CT Scan, but they should be Listened to, and also with a Stethoscope: A Report of a Large Arteriovenous Malformation with a Loud Cranial Bruit.

Background: Arteriovenous malformations (AVMs) are abnormal direct connections between arterial and venous systems, without an interposed capillary bed. This permits high-flow arteriovenous shunting, which precipitates structural changes in the afferent and efferent vessels, namely arterial smooth muscle hyperplasia and thinning of venous walls. Patients with intracranial AVMs typically present with a haemorrhage, headache or seizure. Treatment is either via medical management aimed at control of seizures, headache and blood pressure, or interventional via surgical, radiation or radiologically guided embolisation. Case description: We report the case of a woman in her early 40s presenting with a tonic-clonic seizure against a background of a 31-year history of migraine and an 18-month history of tremors in her right arm. The clinical examination was remarkable for an extremely loud cranial bruit and a right homonymous hemianopia. Imaging diagnosed an 8 cm Martin-Spetzler grade V intracranial arteriovenous malformation in her left parietal lobe, which was deemed unsuitable for operative or radiotherapy-based intervention. Conclusion: The patient was managed through observation and relatively good control of her breakthrough seizures was achieved through the addition of brivaracetam to her lamotrigine and carbamazepine-based therapy, six years after her initial presentation. LEARNING POINTS: Arteriovenous malformations may go undetected for decades.The presence of a cranial bruit is an important sign and tool in diagnosing an intracranial arteriovenous malformation. The presence of a homonymous hemianopia, of which a patient may be unaware, helps to localise an intracranial lesion.The risks of operative or radiological intervention must be balanced with the risks of haemorrhage or refractory seizure when adopting a strategy for the treatment of an intracranial arteriovenous malformation. Good control of epileptic symptoms in those deemed not suitable for operative or radiological intervention can be achieved by careful titration of anti-seizure medications.

A coddling of the sagittal suture: inequality in spring-assisted expansion.

PURPOSE: We examined differences in long-term morphometric outcomes of spring-mediated cranioplasty (SMC) for various forms of isolated nonsyndromic sagittal craniosynostosis. METHODS: A retrospective review was performed of children who underwent SMC from 2011 to 2020 at the Children's Hospital of Philadelphia. Cephalic indices (CI), Whitaker grades, parietal bone thickness, and degree of suture fusion were assessed. Frontal bossing and vertex-nasion-opisthocranion (VNO) angles were compared to a normal control group. RESULTS: Fifty-four subjects underwent surgery at age 3.6 ± 1.0 months with follow-up of 6.3 ± 1.8 years. Mean CI was 75.2 ± 4.1 at 5.9 ± 2.0 years postoperatively. Mean CI were 75.8 ± 4.1 (n = 32), 76.4 ± 4.0 (n = 22), and 77.1 ± 4.8 (n = 11) at 5, 7, and 9+ years postoperatively, respectively. Three (5.6%) required reoperation for persistent scaphocephalic cranial deformity. Fifty-one (94.4%) were Whitaker Grade I. On physical examination, 12 (22.2%) demonstrated craniofacial abnormalities. At long-term follow-up, there were no differences in frontal bossing angle (102.7 ± 5.2 degrees versus 100.7 ± 5.6 degrees, p = .052) and VNO angle (44.9 ± 3.3 degrees versus 43.9 ± 2.2 degrees, p = .063) between study and control groups. Younger age at surgery predicted a lower Whitaker grade, more normalized VNO angle, and greater change in CI during active expansion. Increased percentage fused of the posterior sagittal suture predicted a higher Whitaker grade, while decreased anterior fusion was associated with frontal bossing and temporal hollowing. CONCLUSIONS: Overall, children undergoing spring-mediated cranioplasty for sagittal craniosynostosis demonstrated maintenance of CI, favorable cosmetic outcomes, and a low reoperation rate at mid-term follow-up. Early intervention is associated with improved aesthetic outcomes, and regional fusion patterns may influence long-term craniofacial dysmorphology.

Structural plasticity of pyramidal cell neurons measured after FLASH and conventional dose-rate irradiation.

Evidence shows that ultra-high dose-rate FLASH-radiotherapy (FLASH-RT) protects against normal tissue complications and functional decrements in the irradiated brain. Past work has shown that radiation-induced cognitive impairment, neuroinflammation and reduced structural complexity of granule cell neurons were not observed to the same extent after FLASH-RT (> MGy/s) compared to conventional dose-rate (CONV, 0.1 Gy/s) delivery. To explore the sensitivity of different neuronal populations to cranial irradiation and dose-rate modulation, hippocampal CA1 and medial prefrontal cortex (PFC) pyramidal neurons were analyzed by electron and confocal microscopy. Neuron ultrastructural analyses by electron microscopy after 10 Gy FLASH- or CONV-RT exposures indicated that irradiation had little impact on dendritic complexity and synapse density in the CA1, but did increase length and head diameter of smaller non-perforated synapses. Similarly, irradiation caused no change in PFC prelimbic/infralimbic axospinous synapse density, but reductions in non-perforated synapse diameters. While irradiation resulted in thinner myelin sheaths compared to controls, none of these metrics were dose-rate sensitive. Analysis of fluorescently labeled CA1 neurons revealed no radiation-induced or dose-rate-dependent changes in overall dendritic complexity or spine density, in contrast to our past analysis of granule cell neurons. Super-resolution confocal microscopy following a clinical dosing paradigm (3×10Gy) showed significant reductions in excitatory vesicular glutamate transporter 1 and inhibitory vesicular GABA transporter puncta density within the CA1 that were largely dose-rate independent. Collectively, these data reveal that, compared to granule cell neurons, CA1 and mPFC neurons are more radioresistant irrespective of radiation dose-rate.

Establishment and characterization of a rat model of scalp-cranial composite defect for multilayered tissue engineering.

Composite cranial defects have individual functional and aesthetic ramifications, as well as societal burden, while posing significant challenges for reconstructive surgeons. Single-stage composite reconstruction of these deformities entail complex surgeries that bear many short- and long-term risks and complications. Current research on composite scalp-cranial defects is sparse and one-dimensional, often focusing solely on bone or skin. Thus, there is an unmet need for a simple, clinically relevant composite defect model in rodents, where there is a challenge in averting healing of the skin component via secondary intention. By utilizing a customizable (3D-printed) wound obturator, the scalp wound can be rendered non-healing for a long period (more than 6 weeks), with the cranial defect patent. The wound obturator shows minimal biotoxicity and will not cause severe endocranium-granulation adhesion. This composite defect model effectively slowed the scalp healing process and preserved the cranial defect, embodying the characteristics of a "chronic composite defect". In parallel, an autologous reconstruction model was established as the positive control. This positive control exhibited reproducible healing of the skin within 3 weeks with variable degrees of osseointegration, consistent with clinical practice. Both models provide a stable platform for subsequent research not only for composite tissue engineering and scaffold design but also for mechanistic studies of composite tissue healing.

A Case of Neurosyphilis Presenting with Isolated Abducens Nerve Palsy.

We herein report a case of neurosyphilis that presented with isolated bilateral abducens nerve palsy. A 39-year-old man was referred to our department with diplopia. He had a history of homosexual relationships and showed only bilateral abducens nerve palsy upon a neurological examination. Positive syphilis tests in the serum and cerebrospinal fluid and a contrasting effect on the abducens nerve on magnetic resonance imaging (MRI) confirmed the diagnosis of active neurosyphilis. When a patient manifests isolated abducens nerve palsy, neurosyphilis can be a differential diagnosis, although rare, and contrast-enhanced MRI may help diagnose the disease.

Comparative morphology in the context of facial reduction: Modularity in primate, dog, and bat crania.

Biological variation in the mammalian skull is the product of a series of factors including changes in gene expression, developmental timing, and environmental pressures. When considering the diversity of extant mammalian crania, it is important to understand these mechanisms that contribute to cranial growth and in turn, how differences in cranial morphology have been attained. Various researchers, including Dr. Sue Herring, have proposed a variety of mechanisms to explain the process of cranial growth. This work has set the foundation on which modern analysis of craniofacial morphology happens today. This study focused on the analysis of modularity in three mammalian taxa, all of which exhibit facial reduction. Specifically, we examined facial reduction as a morphological phenomenon through the use of two-module and six-module modularity hypotheses. We recorded three-dimensional coordinate data for 55 cranial landmarks that allowed us to analyze differences in cranial shape in these three taxa (primates n = 88, bats n = 64, dogs n = 81). When assessing modularity within the two-module modularity hypothesis specifically, dogs exhibited the lowest levels of modularity, while bats and primates both showed a slightly more modular covariance structure. We further assessed modularity in the same sample using the Goswami six-module model, where again dogs exhibited a low degree of modularity, with bats and primates being more moderate. We then broke the sample into subsets by analyzing each morphotype separately. We hypothesized that the modularity would be more pronounced in the brachycephalic morphotype. Surprisingly, we found that in brachycephalic dogs, normocephalic dogs, brachycephalic primates, and normocephalic primates, there was a moderate degree of modularity. Brachycephalic bats had a low degree of modularity, while normocephalic bats were the most modular group observed in this study. Based on these results, it is evident that facial reduction is a complex and multifaceted phenomenon with unique morphological changes observed in each of the three taxa studied.

Exploring the atlantic part of the vertebral artery in the South Indian Population and its implications in spine surgery.

Study Design: A descriptive, quantitative cross-sectional study of the atlantic part (V3) of the vertebral artery (VA). Purpose: This study aimed to bridge the research gap in the morphometry of the V3 segment of the VA in the South Indian population. Overview of Literature: The microsurgical anatomy of this segment of the VA has been explored in various populations, and a thorough understanding of the anatomy and course of the VA, particularly the V3 segment, is essential to prevent iatrogenic complications. Several computed tomography studies but a few cadaveric studies have explored the V3 segment of the VA in the South Indian population. Methods: This study examined 40 VAs from 20 embalmed cadavers that were obtained from the voluntary donation program, and Institutional Ethical Clearance was obtained before the study. The length, diameter, and angle of the vertical, horizontal, and exit parts of the V3 segment of the VA were documented after its exposure. Results: The mean lengths of the right and left VAs on each part were nearly similar, except for the mean length of the horizontal part (right: 38.937 mm, left: 40.237 mm) and total length of the V3 segment (right: 66.870 mm, left: 70.350 mm). Conclusions: These morphometric parameters are essential to spine surgeons who intend to operate on a small part (vertical, horizontal, or exit part) of the V3 segment of the VA. The mean values of the parameters obtained in this study give average measurements or safe limits to surgeons for safe surgical procedures such as the occipital condyle screw technique and C1 laminectomy.

Effects of brain radiotherapy strategies on survival in the era of MRI for patients with limited stage small cell lung cancer.

BACKGROUND AND PURPOSE: In the context of the widespread availability of magnetic resonance imaging (MRI) and aggressive salvage irradiation techniques, there has been controversy surrounding the use of prophylactic cranial irradiation (PCI) for small-cell lung cancer (SCLC) patients. This study aimed to explore whether regular brain MRI plus salvage brain irradiation (SBI) is not inferior to PCI in patients with limited-stage SCLC (LS-SCLC). METHODS: This real-world multicenter study, which was conducted between January 2014 and September 2020 at three general hospitals, involved patients with LS-SCLC who had a good response to initial chemoradiotherapy and no brain metastasis confirmed by MRI. Overall survival (OS) was compared between patients who did not receive PCI for various reasons but chose regular MRI surveillance and followed salvage brain irradiation (SBI) when brain metastasis was detected and patients who received PCI. RESULTS: 120 patients met the inclusion criteria. 55 patients received regular brain MRI plus SBI (SBI group) and 65 patients received PCI (PCI group). There was no statistically significant difference in median OS between the two groups (27.14 versus 33.00 months; P = 0.18). In the SBI group, 32 patients underwent whole brain radiotherapy and 23 patients underwent whole brain radiotherapy + simultaneous integrated boost. On multivariate analysis, only extracranial metastasis was independently associated with poor OS in the SBI group. CONCLUSION: The results of this real-world study showed that MRI surveillance plus SBI is not inferior to PCI in OS for LS-SCLC patients who had a good response to initial chemoradiotherapy.

Hinge Craniotomy for Posterior Cranial Vault Expansion: Using the Keel to the Surgeon's Advantage.

Cranial vault reconstructions are a common craniofacial procedure utilized to treat chronically elevated intracranial pressure and its sequelae for children with craniosynostosis. These surgeries often involve split-thickness autologous grafts to facilitate intracranial volume expansion. The hinge craniotomy was developed by neurosurgeons in the early 2000s as an alternative to the hemicraniectomy to allow for greater space and simplified re-securing of the bone flap. In our report, we introduce a novel application of hinge craniotomy in total cranial vault reconstruction for a pediatric patient with microcephaly secondary to congenital cytomegalovirus infection. We performed bilateral barrel stave cuts to the occipital bone as well as an undercut along the midline keel to form a hinge craniotomy. Complex reconstruction followed to augment intracranial volume and restructure the cranial vault. This technique maximized intracranial volume expansion while minimizing the need for prolonged reconstruction. It also allowed for retained vascularization of the bone flap by maintaining the connection with the intact cranial base and pericranium to further support bony healing. Our study presents a novel utilization of hinge craniotomy, using the occipital keel as a natural hinge, to create ample space during cranial vault reconstruction. This technique offers potential advantages in terms of intracranial volume expansion and bony healing.

Atypical Choroid Plexus Tumor of the Cauda Equina With Metastases to the Spinal Cord and Brain.

We report a case of a 57-year-old man with a tumor arising from the cauda equina with spinal cord and intracranial metastases in the basal cisterns and along the cranial nerves. He presented with severe lower back pain and mild gait imbalance. His imaging revealed a large mass in the lumbosacral region with involvement of the cauda equina, intradural extramedullary enhancing metastases in the thoracic spinal canal, and intracranial metastases in the suprasellar cistern and along both trigeminal and facial/vestibulocochlear nerve complexes. Pathological examination of the resected thoracic spinal cord mass showed an atypical papillary proliferation with moderate nuclear pleomorphism and rare mitotic figures. While the morphologic and immunophenotypic features were consistent with the diagnosis of a choroid plexus tumor, the atypical location for this entity required the exclusion of other epithelioid tumors with papillary architecture. Additional immunohistochemical markers were used to exclude a metastatic adenocarcinoma, a papillary variant of a meningioma, and a papillary variant of an ependymoma. Ultimately, methylation-based tumor profiling determined that the methylation class was a match for "plexus tumor" resulting in the integrated diagnosis of the tumor with features of choroid plexus papilloma. This is a unique presentation for both the location and the metastatic spread. The methylation profile was instrumental in establishing this diagnosis.

A Rare Case of Adult-Onset Bilateral Nonspecific Orbital Inflammation (NSOI) With Concomitant Unilateral Third Cranial Nerve Palsy.

Nonspecific orbital inflammation (NSOI), also known as orbital pseudotumor, is a condition characterized by inflammation in the tissues around the eye socket (orbit) without a clearly identifiable cause. This inflammatory disorder can affect various structures within the orbit, including muscles, fat, and connective tissues, leading to symptoms such as pain, swelling, and changes in vision. A 74-year-old man with a history of previous orbital trauma presented with acute-onset head and orbital pain, followed by restricted left eye movements in all directions, left ptosis, and a dilated left pupil. Orbital imaging revealed bilateral inflammation of the lateral rectus muscles and orbital fat, suggestive of bilateral NSOI, while brain and laboratory studies ruled out other differential diagnoses. The presence of left ptosis, a dilated pupil, and limited upward, downward, and inward movements in the left eye suggested intraorbital involvement of both the superior and inferior divisions of the left third nerve. The complete resolution of orbital symptoms and third nerve function after systemic corticosteroid therapy supported the inflammatory nature of the nerve involvement in this case. The case is notable in terms of bilateral involvement in adult-onset NSOI, the possible role of previous orbital trauma in the development of the disease, and the inflammatory involvement of third nerve divisions following the extension of inflammation into the orbital tissues. NSOI can mimic other, more serious conditions, making accurate diagnosis crucial for effective management and treatment. Understanding its presentation, potential causes, and appropriate diagnostic approaches is essential in providing optimal care for patients affected by this complex inflammatory condition.

Brain volume and microglial density changes are correlated in a juvenile mouse model of cranial radiation and CSF1R inhibitor treatment.

Microglia have been shown to proliferate and become activated following cranial radiotherapy (CRT), resulting in a chronic inflammatory response. We investigated the role of microglia in contributing to widespread volume losses observed in the brain following CRT in juvenile mice. To manipulate microglia, we used low-dose treatment with a highly selective CSF1R inhibitor called PLX5622 (PLX). We hypothesized that alteration of the post-CRT microglia population would lead to changes in brain development outcomes, as evaluated by structural MRI. Wild-type C57BL/6J mice were provided with daily intraperitoneal injections of PLX (25 mg/kg) or vehicle from postnatal day (P)14 to P19. Mice also received whole-brain irradiation (7 Gy) or sham irradiation (0 Gy) at 16 days of age. In one cohort of mice, immunohistochemical assessment in tissue sections was conducted to assess the impact of the selected PLX and CRT doses as well as their combination. In a separate cohort, mice were imaged using MRI at P14 (pretreatment), P19, P23, P42 and P63 in order to assess induced volume changes, which were measured based on structures from a predefined atlas. We observed that PLX and radiation treatments led to sex-specific changes in the microglial cell population. Across treatment groups, MRI-detected anatomical volumes at P19 and P63 were associated with microglia and proliferating microglia densities, respectively. Overall, our study demonstrates that low-dose PLX treatment produces a sex-dependent response in juvenile mice, that manipulation of microglia alters CRT-induced volume changes and that microglia density and MRI-derived volume changes are correlated in this model.

Delayed facial nerve palsy after vestibular schwannoma resection: risk factors, extent and prognosis.

INTRODUCTION: Facial nerve palsies may develop during the postoperative period of microsurgical removal of vestibular schwannomas (VSs), even after normal facial function for days or weeks after surgery. The aim of this study was to identify the pathomechanism and predictive factors of delayed palsy. MATERIAL AND METHOD: The clinical data of 193 patients who underwent vestibular schwannoma surgery between 2012 and 2021 were retrospectively analyzed. A total of 134 patients were included. The patients showed intact facial nerve function up to 24 h after surgery. All patients (n = 20) with palsy from postoperative day 4 were included and collectively referred to as delayed facial nerve palsy (DFNP). Various factors were checked using a binomial regression analysis. RESULTS: The mean age of patients with DFNP was 57.8 years (55% female, 45% male). 70% had VS with KOOS ≥ 3, and 60% underwent surgery via a translabyrinthine approach Among the 16 patients with DFNP-related neurotropic pathogens, 25% were seropositive for herpes simplex virus. Most patients (n = 9/20) experienced onset of palsy between postoperative days 6 and 10. Of the four variables included in the significance test, three were significant: KOOS ≥ 3 (p < .04), ipsilateral vestibular organ failure (p < .05), and age group (p < .03). After therapy, 100% of patients recovered almost complete facial nerve function. The parameters mentioned above (KOOS classification and ipsilateral vestibular dysfunction) could be proven risk factors for the occurrence of DFNP.