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Summary A 20‐year‐old Irish Sport Horse gelding was presented to the Royal Veterinary College Equine Referral Hospital for investigation of left‐sided epistaxis, depression and gait abnormalities of approximately 1 month duration. Physical examination and cranial nerve evaluation were unremarkable. A small amount of haemorrhagic discharge was noted from the left nostril. Gait evaluation was suggestive of proprioceptive deficits. Computed tomography (CT) identified a mass lesion within the left conchofrontal and sphenopalatine sinuses extending through the cribriform plate into the calvarium. Histopathology of the mass revealed a neuroendocrine neoplasm, for which a diagnosis of esthesioneuroblastoma was favoured. This case highlights the usefulness of CT for the identification and extent of an intracranial mass and therefore its prognosis, however, histopathological examination was necessary to confirm the diagnosis. [ABSTRACT FROM AUTHOR]

We report a case of a 58-year-old man with a history of nasal obstruction and recurrent epistaxis who underwent videonasolaryngoscopy after 9 months of symptoms. The frst images showed a hyperemic mass affecting the left middle turbinate up to the nasal cleft. Computed tomography described a mass with an expansive effect occupying the entire left frontal sinus and most of the left ethmoid cells, widening the frontal sinus drainage path, and creating a continuity break of the cribriform plate, the left papyraceous lamina, and the upper-third of the nasal septum. Magnetic resonance imaging suggested T1-isointensity and T2-hyperintensity, intense contrast uptake, and no involvement of meningeal or brain tissues. The patient underwent extended endoscopic surgery without previous endovascular embolization or adjuvant therapies. A contralateral inferior turbinate graft was applied over the cribriform plate. Histopathological examination suggested glomangiopericytoma (GPC), and immunohistochemistry confrmed the diagnosis with positive beta-catenin, smooth muscle actin, and cyclin D1. The patient presented no nasal symptoms up to a 9-month follow-up. Nasal endoscopy showed no tumor recurrence signal. Although fronto-ethmoidal GPC is a rare tumor and presents challenging surgical access, it can be safely excised by endoscopic surgery. However, careful short- and long-term endoscopic follow-ups remain necessary to prevent postoperative complications and maintain surveillance of recurrences. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To describe the CT findings of Australian dogs and cats with nasal cryptococcosis over a 12-year period. ANIMALS: 12 dogs and 9 cats diagnosed with nasal cryptococcosis from 2008 through 2020. METHODS: CT findings were compared among enrolled cases from Australian veterinary referral centers. Disease severity was compared between a subset of patients with cryptococcal speciation performed (n = 6 dogs; n = 3 cats) and geographic domicile. RESULTS: Dogs demonstrated diffuse disease affecting numerous nasal regions and sinuses. Cats displayed more focal nasal and nasopharyngeal disease. Dogs were more likely to have a nasal mass, whereas cats were more likely to have a nasopharyngeal mass. Cribriform plate lysis was common in dogs but not observed in cats. Sinonasal osteolysis was a common feature in both species. Mandibular lymph nodes were commonly enlarged in dogs, whereas in cats, the retropharyngeal lymph nodes were more likely enlarged. There was no obvious difference in disease severity or lesion distribution in relation to the causal species of Cryptococcus, although to determine if this finding is robust, an appropriately powered prospective study is warranted. [ABSTRACT FROM AUTHOR]

Background: Prognostic factors in dogs with nasal tumors include several variables. However, factors that can measure prognosis have not yet been identified due to considerable divergence among reports. Aim: To describe the computed tomography (CT) imaging, treatment, and outcomes of dogs with nasal tumors, as well as detect negative prognostic factors through the analysis of a substantial number of cases from a single institution. Furthermore, based on CT findings, this study aimed to identify independent prognostic factors for nasal tumors in dogs. Methods: A total of 166 client-owned dogs were diagnosed with nasal tumors at Gifu University Veterinary Hospital between 2015 and 2019. Data were retrospectively collected from the electronic medical records. Results: Univariate analysis revealed a significant difference in survival time between adenocarcinoma and squamous cell carcinoma in 166 canine nasal tumors treated with megavoltage (MeV) radiation therapy at a single institution (p = .015). There was a significant difference in survival time between carcinoma and sarcoma (p = .04). Regarding CT imaging findings, significant differences in survival time were observed for frontal sinus invasion (p = .007), cribriform plate destruction (p < .001), and lymph node metastasis (p = .003). Multivariate Cox regression analysis was performed to assess frontal sinus invasion, cribriform plate destruction, histopathologic subtypes, and lymph node metastasis as negative prognostic factors; however, only cribriform plate destruction was a significant negative prognostic factor for survival time (p = .004). Conclusion: Multivariate Cox regression analysis showed that cribriform plate destruction was the main factor in predicting a negative prognosis among 166 canine nasal tumors treated with MeV radiation therapy at a single institution. Therefore, we propose a new 2-tier staging classification for canine nasal tumors with the presence or absence of cribriform plate destruction based on CT examination as the only evaluation factor. [ABSTRACT FROM AUTHOR]

ABSTRACTCerebrospinal fluid (CSF) plays a crucial role in the brain's lymphatics as it traverses the central nervous system (CNS). Its primary function is to facilitate the outward transport of waste. Among the various CSF outflow pathways, the route through the cribriform plate along the olfactory nerves stands out as the most predominant. This review describes the outflow pathway of CSF into the nasal lymphatics. Additionally, we examine existing studies to describe mutual influences observed between the brain and extracranial regions due to this outflow pathway. Notably, pathological conditions in the CNS often influence CSF outflow, leading to observable changes in extracranial regions. The established connection between the brain and the nose is significant, and our review underscores its potential relevance in monitoring CNS ailments, including neurodegenerative diseases. Considering that aging – the most significant risk factor for the onset of neurodegeneration – is also a principal factor in CSF turnover alterations, we suggest a novel approach to studying neurodegenerative diseases in therapeutic terms.

Objectives Transorbital neuroendoscopic surgery (TONES) has ignited interest in the transorbital access corridor, increasing its use for single and multi-portal skull base interventions. However, the crowding of a small corridor and two-dimensional viewing restrict this access portal. Design Cadaveric qualitative study to assess the feasibility of transorbital microsurgery (TMS). Setting Anatomical dissection steps and instrumentation were recorded for homogeneous methodology. Participants Six cadaveric specimens were systematically dissected using TMS to the anterior cranial fossa and paramedian structures. Main Outcome Measures Anatomical parameters of the TMS craniectomy were established, and the visible and accessible neuroanatomy was highlighted. Results A superior lid crease incision achieved essential orbital rim exposure and preseptal dissection. The orbital roof craniectomy is defined by three boundaries: (1) frontozygomatic suture to the frontosphenoid suture, (2) frontal sinus and cribriform plate, and (3) frontal sinus and orbital rim. The mean (standard deviation) craniectomy was 440 mm 2 (78 mm 2). Exposing the ipsilateral optic nerve and internal carotid artery obviated the need for frontal lobe retraction to identify the A1–M1 bifurcation as well as near-complete visualization of the M1 artery. Conclusion TMS is a feasible corridor for intracranial access. Mobilization of orbital contents is imperative for maximal intracranial access and protection of the globe. TMS enables access to the frontal lobe base, ipsilateral optic nerve, and most of the ipsilateral anterior circulation. This cosmetically satisfactory approach causes minimal destruction of the anterior skull base with satisfactory exposure of the anterior cranial fossa floor without sinus invasion. [ABSTRACT FROM AUTHOR]

Although cryptococcosis is the most common systemic fungal disease of cats, abdominal involvement is rarely reported. The pathogenesis of cryptococcosis usually involves sinonasal colonisation, followed by tissue invasion and sinonasal infection, with possible subsequent spread to the lungs and/or direct extension into the central nervous system (CNS), for example, via the cribriform plate. Further haematogenous spread can occur to any tissue, including skin and the CNS. This report describes a case of disseminated cryptococcosis due to Cryptococcus neoformans species complex in a 13‐year‐old cat, the fourth documented Australian feline case with abdominal involvement. The cat presented with a chronic history of upper respiratory disease that progressed to severe lethargy and anorexia. An autopsy revealed striking peritonitis with multifocal abdominal involvement affecting the liver, spleen, adrenal glands, kidneys, pancreas and mesentery. Cryptococcal organisms were also observed in organs within the thoracic cavity, sinonasal tissues and the CNS. Testing of abdominal fluid and serum for cryptococcal antigen using a commercially available lateral flow assay using neat fluid specimen initially tested false‐negative. However, after dilution of the sample to 1:64, a positive result was obtained, confirming a postzone phenomenon. Taken together, the collective findings were indicative of widely disseminated cryptococcosis due to Cryptococcus neoformans with atypical involvement of the abdominal cavity. [ABSTRACT FROM AUTHOR]

This study presents a new treatment planning approach merging 3D-CRT and VMAT fields into a hybrid treatment plan (HybTP), in order to achieve an optimum dose coverage of the planning target volume (PTV) and protection of OAR. Craniospinal axis irradiation (CSI) treated with 3D conformal radiotherapy (3D-CRT) is associated with high doses to the heart and eye lenses but provides better sparing of lungs and kidneys compared to volumetric modulated arc therapy (VMAT). VMAT treatment spares eye lenses and the heart, but lungs and kidneys are not as effective as 3D-CRT. Thus, a combination of both techniques (HybTP) may be optimal in sparing all these organs at risk (OAR). The results of HybTP are compared with helical tomotherapy (HT), intensity modulated radio therapy (IMRT), VMAT, and 3D-CRT plans. Hybrid, HT, VMAT, IMRT, and 3D-CRT treatment plans for a male child (age 6 years) with medulloblastoma were created and compared. A total dose of 35.2 Gy (PTV) with a dose per fraction of 1.6 Gy was prescribed. The following dose acceptance criteria were defined: (1) Mean PTV dose should be 100% of the prescribed dose, while the maximum dose should not exceed 107%. (2) At least 98% of the PTV should receive 95% of the prescribed dose. (3) The cribriform plate should be covered by the 95% isodose line. (4) The acceptance criteria for the OARs were: lenses D max <10 Gy, lungs D mean <7 Gy, kidneys D mean <15 Gy, heart D mean <26 Gy, and heart V 25 <10%. The plans were compared regarding dose homogeneity index (HI) and conformity index (CI), PTV coverage, (particularly at cribriform plate) and doses at OARs. Best conformity was achieved with HT (CI = 0.98) followed by VMAT (CI = 0.96), IMRT (CI = 0.91), HybTP (CI = 0.86), and 3D-CRT (CI = 0.83). The homogeneity index varied marginally. For both HT and IMRT the HI was 0.07, and for 3D-CRT, VMAT and HybTP the HI was between 0.13 and 0.15. The cribriform plate was sufficiently covered by HybTP, VMAT, and 3D-CRT. The dose acceptance criteria for OARs were met by HT and HybTP. VMAT did not meet the criteria for lung (D mean = right 10.4 Gy/left 10.2 Gy), 3D-CRT did not meet the criteria for eye lenses (D max = right 32.3 Gy/left 33.1), and heart (V 25 ≈44%) and IMRT did not meet the criteria for lung (D mean = right 11.1 Gy/left 11.2 Gy) and eye lenses (D max = right 12.2 Gy/left 13.1). HybTP meets all defined acceptance criteria and has proved to be a reasonable alternative for CSI. With HybTP that combines VMAT at the brain and heart with 3D-CRT posterior spinal fields (to spare lungs and kidneys), both appropriate coverage of the PTV and sparing of OAR can be achieved. [ABSTRACT FROM AUTHOR]

Meningoencephalocele is an uncommon disorder in dogs, that has detrimental effects on both the duration and quality of life. Dogs afflicted by this condition may exhibit neurological deficits, epileptic seizures, and behavioral disorders. A 4-month-old female Anatolian Shepherd dog, weighing 13 kg presented for further investigation of a 3-week history of cluster, grand mal seizures. No abnormalities were evident on physical examination. A full neurological examination, including cranial nerve assessment was unremarkable, except a slight right proprioceptive deficit on the right front leg. MRI of the brain was performed. Protrusion of the right rostral rhinencephalon through the defect of the right cribriform plate and a right basal ethmoidal meningoencephalocele was detected. Due to the dog's age, aggressive temperament, and current clinical status, medical management was preferred, and the dog was managed on phenobarbital and levetiracetam. Seizures have remained well controlled 12 months post-diagnosis. [ABSTRACT FROM AUTHOR]

The endoscopic approach has gained popularity in cerebrospinal fluid (CSF) rhinorrhea repair with high success rates, yet recurrence is frequent. We analyzed our cases to determine the outcomes of endoscopic repair of CSF rhinorrhea and the effect of several perioperative factors on the success of repair. A retrospective review of 50 patients who underwent endoscopic repair of CSF rhinorrhea between January 2013 and July 2023 was performed, collecting details of presentation, surgery, and postoperative period. The most frequent etiology was nontraumatic CSF rhinorrhea (76%), in which the defect was most commonly located at the left cribriform plate, followed by traumatic CSF rhinorrhea (24%), in which sphenoid defects were most frequent. Traumatic CSF rhinorrhea was more common among male patients and was significantly associated with anosmia. Success rate at first repair attempt was 84%. Persistent CSF rhinorrhea was present in 3 patients (6%), and 5 patients (10%) developed recurrence of CSF rhinorrhea. Overall, 7 patients required reoperation, with 100% success rate after the second surgery. The use of 3-layered repair with fat, fascia lata, and mucosal flap was protective against repair failure, whereas bilateral defects and duration of symptoms >1 year were significantly associated with repair failure. The use of lumbar drain did not demonstrate a difference in repair success rate. Endoscopic repair of CSF rhinorrhea appears to be safe and effective when performed with accurate localization of the site of the lesion and multilayered repair. Potential predictors of recurrence include bilateral and long-standing defects. [ABSTRACT FROM AUTHOR]

Purpose: It is unclear if septal deviation at the insertion points to the nasal cavity is associated with the overall septal deviation. This study aimed to assess septal deviation at the cribriform plate (CP) and maxillary crest (MC) using CT scans and to see if there was any correlation with overall septal deviation. Methods: All consecutive CT sinus scans between January 2020 and December 2021 were retrospectively reviewed. Patients were excluded if they had a history of head, nasal or facial trauma, or any previous nasal surgical procedure. Angles between the septum and MC and the septum and CP as well as maximal angle of septal deviation (MSD) were measured. Results: A total of 70 scans were included in the final analysis. The mean MSD was 8.14°. The mean septal deviation was 0.89° at the CP and 2.02° at the MC. The correlation coefficient between the deviation at the CP and MSD was 0.025 and between the deviation at the MC and MSD was 0.321. Conclusion: Our data reveal a positive correlation between septal deviation at the floor of the nose and overall septal deviation; this was not observed at the septal deviation at the roof. This could be explained due to the inherent tilt in the cribriform plate or by earlier ossification and fixation of the septum during its development at its insertion to the roof, thereby allowing further growth and potential for deviation of the lower part of the septum and its insertion to the floor. [ABSTRACT FROM AUTHOR]

Background: Reduced clearance of cerebrospinal fluid (CSF) has been suggested as a pathological feature of Alzheimer's disease (AD). With extensive documentation in non-human mammals and contradictory human neuroimaging data it remains unknown whether the nasal mucosa is a CSF drainage site in humans. Here, we used dynamic PET with [1-11C]-Butanol, a highly permeable radiotracer with no appreciable brain binding, to test the hypothesis that tracer drainage from the nasal pathway reflects CSF drainage from brain. As a test of the hypothesis, we examined whether brain and nasal fluid drainage times were correlated and affected by brain amyloid. Methods: 24 cognitively normal subjects (≥ 65 years) were dynamically PET imaged for 60 min. using [1-11C]-Butanol. Imaging with either [11C]-PiB or [18F]-FBB identified 8 amyloid PET positive (Aβ+) and 16 Aβ- subjects. MRI-determined regions of interest (ROI) included: the carotid artery, the lateral orbitofrontal (LOF) brain, the cribriform plate, and an All-turbinate region comprised of the superior, middle, and inferior turbinates. The bilateral temporalis muscle and jugular veins served as control regions. Regional time-activity were used to model tracer influx, egress, and AUC. Results: LOF and All-turbinate 60 min AUC were positively associated, thus suggesting a connection between the brain and the nose. Further, the Aβ+ subgroup demonstrated impaired tracer kinetics, marked by reduced tracer influx and slower egress. Conclusion: The data show that tracer kinetics for brain and nasal turbinates are related to each other and both reflect the amyloid status of the brain. As such, these data add to evidence that the nasal pathway is a potential CSF drainage site in humans. These data warrant further investigation of brain and nasal contributions to protein clearance in neurodegenerative disease. [ABSTRACT FROM AUTHOR]

Spontaneous cerebrospinal fluid (CSF) leaks are an uncommon clinical entity, often challenging to diagnose accurately. We present a unique case of a patient with symptoms suggestive of an ethmoidal CSF leak, initially supported by radiological findings, but ultimately revealed to be a mid-clival CSF leak (from the posterior wall of the sphenoid sinus). This case underscores the complexities of diagnosing CSF leaks and highlights the importance of surgical exploration in cases where radiological evidence appears contradictory. The patient's Computed Tomography scan indicated a CSF leak in the cribriform plate, prompting a surgical approach to address this region. However, intraoperative findings surprisingly revealed no evidence of leak in the cribriform plate but instead a posterior wall of the sphenoid defect as the culprit. This report emphasizes the critical role of interdisciplinary collaboration, meticulous preoperative and intraoperative assessment, and adaptability in managing challenging cases of CSF leaks, ultimately leading to successful surgical repair and improved patient outcomes. It serves as a valuable reminder for clinicians to consider the possibility of a masquerading CSF leak when clinical and radiological findings do not align, thereby facilitating more precise diagnosis and targeted treatment. [ABSTRACT FROM AUTHOR]

Summary: Background: Atraumatic subarachnoid haemorrhage (SAH) is associated with high morbidity and mortality. Proposed mechanisms for red blood cell (RBC) clearance from the subarachnoid space (SAS) are erythrolysis, erythrophagocytosis or through efflux along cerebrospinal fluid (CSF) drainage routes. We aimed to elucidate the mechanisms of RBC clearance from the SAS to identify targetable efflux pathways. Methods: Autologous fluorescently-labelled RBCs along with PEGylated 40 kDa near-infrared tracer (P40D800) were infused via the cisterna magna (i.c.m.) in female reporter mice for lymphatics or for resident phagocytes. Drainage pathways for RBCs to extracranial lymphatics were evaluated by in vivo and in situ near-infrared imaging and by immunofluorescent staining on decalcified cranial tissue or dural whole-mounts. Findings: RBCs drained to the deep cervical lymph nodes 15 min post i.c.m. infusion, showing similar dynamics as P40D800 tracer. Postmortem in situ imaging and histology showed perineural accumulations of RBCs around the optic and olfactory nerves. Numerous RBCs cleared through the lymphatics of the cribriform plate, whilst histology showed no relevant fast RBC clearance through dorsal dural lymphatics or by tissue-resident macrophage-mediated phagocytosis. Interpretation: This study provides evidence for rapid RBC drainage through the cribriform plate lymphatic vessels, whilst neither fast RBC clearance through dorsal dural lymphatics nor through spinal CSF efflux or phagocytosis was observed. Similar dynamics of P40D800 and RBCs imply open pathways for clearance that do not impose a barrier for RBCs. This finding suggests further evaluation of the cribriform plate lymphatic function and potential pharmacological targeting in models of SAH. Funding: Swiss National Science Foundation (310030_189226), SwissHeart (FF191155).

An uncommon entity in the class of malignant neuroectodermal nasal tumors is the olfactory neuroblastoma, which originates in the roof of the nasal cavity from the olfactory epithelium. It is often mistaken by clinicians for a nasal polyp because it presents with indistinct features such as nasal obstruction and secondary sinus disease. Olfactory neuroblastoma has been observed to cause morbidity by distant metastasis, invasion through the cribriform plate, and secondary meningitis in most instances. It exhibits a range of biologic activities, from slow growth accompanied by long-term patient survival to a very aggressive malignancy with extensive metastases. We report the incidence of a rare case in which a patient, previously operated on and irradiated for squamous cell carcinoma of the maxilla, developed an olfactory neuroblastoma with orbital protrusion. [ABSTRACT FROM AUTHOR]

Detailed visualization of the cribriform plate is challenging due to its intricate structure. This study investigates how computed tomography (CT) with a novel photon counting (PC) detector enhance cribriform plate visualization compared to traditionally used energy-integrated detectors in patients. A total of 40 patients were included in a retrospective analysis, with half of them undergoing PC CT (Naeotom Alpha Siemens Healthineers, Forchheim, Germany) and the other half undergoing CT scans using an energy-integrated detector (Somatom Sensation 64, Siemens, Forchheim, Germany) in which the cribriform plate was visualized with a temporal bone protocol. Both groups of scans were evaluated for signal-to-noise ratio, radiation dose, the imaging quality of the whole scan overall, and, separately, the cribriform plate and the clarity of volume rendering reconstructions. Two independent observers conducted a qualitative analysis using a Likert scale. The results consistently demonstrated excellent imaging of the cribriform plate with the PC CT scanner, surpassing traditional technology. The visualization provided by PC CT allowed for precise anatomical assessment of the cribriform plate on multiplanar reconstructions and volume rendering imaging with reduced radiation dose (by approximately 50% per slice) and higher signal-to-noise ratio (by approximately 75%). In conclusion, photon-counting technology provides the possibility of better imaging of the cribriform plate in adult patients. This enhanced imaging could be utilized in skull base-associated pathologies, such as cerebrospinal fluid leaks, to visualize them more reliably for precise treatment.

There is increasing interest in developing a minimally invasive imaging modality to safely evaluate dynamic microscopic changes of the olfactory mucosa and cribriform foramina. Herein, we utilized three-dimensional (3D) optical coherence tomography (OCT) to characterize the ex vivo stratified substructure of olfactory mucosa in rabbits and create 3D reconstructed images of olfactory foramina. Olfactory mucosa and cribriform plates from four New Zealand White rabbits were dissected and imaged using two swept-source OCT systems: (1) 1.3-µm (μm) center wavelength, 100-nm bandwidth, 200-kHz sweep rate, and (2) 1.7-μm center wavelength, 120-nm bandwidth, 90-kHz sweep rate. Volumetric OCT images were compiled to create a 3D reconstruction of the cribriform plate. The ability of OCT to distinguish the olfactory mucosa substructure and foramina was compared to histology. To estimate imaging penetration depth of each system, the first-order exponential decays of depth-resolved intensity were calculated and compared using a paired t-test. Three-dimensional OCT depicted the stratified layered structures within the olfactory mucosa correlating with histology. The epithelium and lamina propria were measured to be 32 μm and 107 μm in 1.3-μm OCT compared to 30 μm and 105 μm in histology. Olfactory foramina were visualized via 3D reconstruction. The 1.7-μm system provided greater depth penetration compared to the 1.3-μm system, allowing for improved foramina visualization. We have shown that OCT can be used to image non-pathologic olfactory mucosa and foramina. Implications for this work include diagnostic and therapeutic potentials for neurorhinological and neurodegenerative diseases.

Background: Iatrogenic cerebrospinal fluid leak (iCSF-L) is a major complication of endonasal surgeries whose occurrence is always a potential adverse event due to anatomical variation/asymmetry of the skull base (SB). The aim of this manuscript is to provide a topographical map of iCSF-L and to investigate the role of SB asymmetry in iCSF-L occurrence. Methods: In this retrospective study, the location of iCSF-L dural defect was studied and compared to patients affected by spontaneous and post-traumatic CSF-L. Considering only iCSF-L, after having collected the SB asymmetry data, the Keros, Gera, distance of the anterior ethmoidal artery from the SB, frontal sinus pneumatization, and Thailand–Malaysia–Singapore score classifications were compared to a control group of patients. Results: A total of 153 CSF-Ls (103 spontaneous, 37 iatrogenic, and 13 traumatic) were included. A significant association was noted (p < 0.001) between the nature of the CSF-L and the areas involved. Considering iCSF-Ls, only the Gera classification was significantly different (p < 0.05) and the most reliable in predicting the risk of dural transgression (AUC = 0.719). Conclusions: ICSF-Ls present peculiar regional SB involvement with the cribriform plate, with the ethmoidal roof being the most involved. After having assessed the asymmetry of the SB, the Gera classification was the most reliable one. [ABSTRACT FROM AUTHOR]

In mammalian research, it has been debated what can initiate an evolutionary tradeoff between different senses, and the phenomenon of sensory tradeoff in rodents, the most abundant mammalian clade, is not evident. The Nile rat (Arvicanthis niloticus), a murid rodent, recently adapted to a diurnal niche through an evolutionary acquisition of daylight vision with enhanced visual acuity. As such, this model provides an opportunity for a cross-species investigation where comparative morphological and multi-omic analyses of the Nile rat are made with its closely related nocturnal species, e.g. the mouse (Mus musculus) and the rat (Rattus norvegicus). Thus, morphological examinations were performed, and evolutionary reductions in relative sizes of turbinal bone surfaces, the cribriform plate, and the olfactory bulb were discovered in Nile rats. Subsequently, we compared multiple murid genomes, and profiled olfactory epithelium transcriptomes of mice and Nile rats at various ages with RNA sequencing. The results further demonstrate that, in comparison with mouse olfactory receptor (OR) genes, Nile rat OR genes have experienced less frequent gain, more frequent loss, and more frequent expression reduction during their evolution. Furthermore, functional degeneration of coding sequences in the Nile rat lineage was found in OR genes, yet not in other genes. Taken together, these results suggest that acquisition of improved vision in the Nile rat has been accompanied by degeneration of both olfaction-related anatomical structures and OR gene repertoires, consistent with the hypothesis of an olfaction-vision tradeoff initiated by the switch from a nocturnal to a diurnal lifestyle in mammals. [ABSTRACT FROM AUTHOR]

Detailed visualization of the cribriform plate is challenging due to its intricate structure. This study investigates how computed tomography (CT) with a novel photon counting (PC) detector enhance cribriform plate visualization compared to traditionally used energy-integrated detectors in patients. A total of 40 patients were included in a retrospective analysis, with half of them undergoing PC CT (Naeotom Alpha Siemens Healthineers, Forchheim, Germany) and the other half undergoing CT scans using an energy-integrated detector (Somatom Sensation 64, Siemens, Forchheim, Germany) in which the cribriform plate was visualized with a temporal bone protocol. Both groups of scans were evaluated for signal-to-noise ratio, radiation dose, the imaging quality of the whole scan overall, and, separately, the cribriform plate and the clarity of volume rendering reconstructions. Two independent observers conducted a qualitative analysis using a Likert scale. The results consistently demonstrated excellent imaging of the cribriform plate with the PC CT scanner, surpassing traditional technology. The visualization provided by PC CT allowed for precise anatomical assessment of the cribriform plate on multiplanar reconstructions and volume rendering imaging with reduced radiation dose (by approximately 50% per slice) and higher signal-to-noise ratio (by approximately 75%). In conclusion, photon-counting technology provides the possibility of better imaging of the cribriform plate in adult patients. This enhanced imaging could be utilized in skull base-associated pathologies, such as cerebrospinal fluid leaks, to visualize them more reliably for precise treatment. [ABSTRACT FROM AUTHOR]

Cribriform Gleason pattern 4 and intraductal carcinoma of the prostate are adverse pathologic features. We retrospectively assessed their impact when added to CAPRA and NCCN pretreatment tools in 3 patient cohorts (Toronto, Wisconsin and Rotterdam) and show improved patient stratification for both biochemical recurrence and development of metastases and death of disease (events) with their inclusion. Background: Pretreatment stratification tools can help in clinical decision making in prostate cancer. To date, none incorporates well-established routinely reported adverse prognostic pathologic features such as intraductal carcinoma of prostate (IDC) or cr ibr ifor m patter n 4 (CC). Objective: To assess the impact of addition of CC and/or IDC on the Cancer of Prostate Risk Assessment (CAPRA) and National Cancer Comprehensive Network (NCCN) tools for predicting biochemical recurrence free survival (BCR-FS) and event-free survival (EFS) across multiple patient cohorts. Design, setting, and participants: Matched prostate biopsies and radical prostatectomies from institutions in Toronto, Wisconsin and Rotterdam. The presence/absence of CC/IDC was recorded on all biopsies. Outcome measurements and statistical analysis: Relationship to outcome was assessed using Cox proportional hazard models, ANOVA and Harrell's concordance index. Results and limitations: We included 1326 patients (Toronto-612, Wisconsin-542, Rotterdam-172) with median follow up of 4.2 years (IQR 2.9-6.4 years); 306 (23.1%) had CC/IDC on biopsy with 207 (20.9%) BCR and 154 (11.6%) events (metastases/death). Addition of CC/IDC improved stratification in CAPRA scores 3 to 5 for BCR-FS (c-index increase 0.633-0.658, P < .001) and scores 6-10 for EFS (c-index increase 0.653-0.697, P < .001). For NCCN, all risk groups apart from score 1 to 2 showed improvement in BCR-FS (c-index increase 0.599-0.636, P < 0.001) and EFS prediction (c-index increase 0.648-0.697, P < .001). Sub-analysis of grade group (GG) 2 biopsies showed similar findings. The retrospective nature and inclusion of cases only reported by genitourinary pathologists are study limitations. Conclusions: The clinical benefit of the addition of CC/IDC to both CAPRA and NCCN pretreatment tools was validated in 3 cohorts, including the subset of biopsy GG2 prostate cancer patients. Patient summary: Including additional pathologic features to existing pretreatment, clinical decision making tools improves the ability to predict prostate cancer recurrence, cancer spread and death of disease. [ABSTRACT FROM AUTHOR]

Introduction: Cerebrospinal Fluid (CSF) rhinorrhea results from breakdown in the integrity of structures separating the subarachnoid space and nasal cavity, namely subarachnoid space and dura mater, the bony skull base and periostea alongside the upper aerodigestive tract mucosa. Endoscopic repair is considered the treatment of choice for CSF rhinorrhea. Our aim of study was to analyze the etiopathogenesis and outcomes of treatment. Material and Methods: A retrospective study review of patients treated with endoscopic repair of CSF rhinorrhea at tertiary care hospital in ENT Department Benazir Bhutto hospital Rawalpindi from august 2013 to September 2017 identified 25 patients. Majority of them were male. The defects were closed in three layers using fat, fascia lata and nasal mucosa along with fibrin sealant in majority of patients. Pre operatively subarachnoid drain was placed in all patients. Patients were followed up to 3 months. Results: Forty-four patients underwent endoscopic repair of CSF rhinorrhea. The age group ranged from 16 to 55 years. Of the total of 44 patients 26 (59%) were males and 18(41%) females. The mean age of the patients in our study was 32.8 ± 9.7. Post trauma CSF leak was seen up to 52.3% of the patients. The most common site of leakage was identified Cribriform plate area. Our success rate of endoscopic repair was 88.6%. The most commonly observed complication was meningitis that was observed in 2 (4.5%) of the patients that too were managed conservatively. Conclusion: Accurate localization of site of leakage appears to be essential for successful endoscopic repair of CSF rhinorrhea. In our study cribriform plate area was commonly observed area of CSF leak. In our study, the success rate was 88.6% and low complication rate 4.5%. [ABSTRACT FROM AUTHOR]

CSF (Cerebro Spinal Fluid) rhinorrhoea occurs when the fluid leaks from subarachnoid space into the nasal cavity. The study aims to find out the prevalence and demographic distribution of CSF leak and to describe the site of the CSF leak along with the management. We did a prospective study on 180 patients admitted with head injury in neurosurgery department, along with the patients who came to ENT department with unilateral nasal discharge during the time period from March 2017 to March 2021. A total of 36 cases of CSF leak were obtained during the time period. The etiology in 18 cases was head injury & the other 18 cases were either due to infectious or nontraumatic causes. In our study, 26(72.22%) patients were aged less than 50 years. Incidence was more among males compared to females. The most common etiology was head injury - 18(50%) patients followed by the spontaneous leak- 16 (44.44%) patients with the most common site as the cribriform plate. Endoscopic repair using a hadad flap was done in most of the patients. Trauma due to head injury is the most common etiology in CSF rhinorrhea with more number of patients aged less than 50 years. Most of the leaks can be repaired successfully with the use of endoscope with excellent illumination & localizing the exact site of the leak. [ABSTRACT FROM AUTHOR]

This article, titled "Facial Reconstruction following the Resection of Familial Gigantiform Cementoma Adjacent to the Skull Base: Technical Note," describes a case of familial gigantiform cementoma (FGC), a rare benign neoplasm that can cause significant facial disfigurement. The article discusses the successful reconstruction of a 36-year-old female patient's face after multiple prior surgeries performed at outside facilities. The surgical team used a combination of open trans-fascial resection and a complex fibular free flap to achieve both oncologic control and cosmesis. The article emphasizes the complexity of FGC operations and the importance of multidisciplinary planning for resection and reconstruction. [Extracted from the article]

This article discusses the management of a rare case of a progressive giant maxillary ameloblastoma, a type of odontogenic epithelial tumor that typically occurs in the jaw. The patient, a 53-year-old male, had previously undergone surgery for ameloblastoma but presented with a massive expansion of the tumor. The article explores the options for managing ameloblastoma and the factors that contribute to its progression. Surgical resection was performed, and targeted therapy was considered for future treatment. The article emphasizes the importance of complete removal of the tumor to minimize the risk of recurrence or progression. [Extracted from the article]

This article compares the endoscopic endonasal approach (EEA) and the transcranial approach (TCA) for the resection of olfactory groove meningiomas (OGM). The study found that EEA is associated with lower complication rates and higher rates of Simpson grade I resection compared to TCA. However, TCA showed higher rates of postoperative infection. The authors suggest that further research and collaboration are needed to determine the anatomical indications for each procedure. [Extracted from the article]

The article titled "The Anatomical Study of the Cribriform Plate—New Concept: Is the Cribriform Plate an Effective Border?" explores the importance of the cribriform plate in the anterior skull base area. The study examines the structure of the cribriform plate and its relationship to functions such as smelling, tasting, and sexual-behavioral functions. The research includes macroscopic bone study and microscopic study, revealing the complex labyrinth-like structure of the cribriform plate and the presence of vessels and nerves within it. The article concludes that the cribriform plate is a delicate border that plays a role in trauma and tumor development. [Extracted from the article]

The article discusses a surgical technique called the V-Bridge Reconstruction Technique, which is used to secure a pericranial flap in combined transbasal/endoscopic endonasal approaches for anterior skull base lesions. The pericranial flap is used to reconstruct the cribriform defect after tumor resection and prevent complications such as CSF leakage and pneumocephalus. The technique involves securing the flap to the orbital roofs using microfixation plates or sutures. The article reports on the successful use of this technique in six patients, with no postoperative complications observed except for one case that was successfully revised. Overall, the V-Bridge Reconstruction Technique is found to be effective in preventing flap migration and associated complications in transbasal approaches for anterior skull base lesions. [Extracted from the article]

This article discusses a pilot simulation study that utilized 3D printed sinus models to simulate the repair of an anterior skull base defect using a nasoseptal flap. Thirteen otolaryngology residents participated in the study, performing the procedure on the 3D models. The study found that participants significantly improved in confidence, speed, and procedural adequacy after receiving feedback and instruction. The simulation was deemed highly applicable and participants reported a high level of satisfaction with the overall learning experience. [Extracted from the article]

This article provides a descriptive series on biphenotypic sinonasal sarcoma (BSNS), an extremely rare malignancy with limited clinical experience and data on treatment outcomes. The study reports on the clinicopathological characteristics and treatment outcomes of 16 patients with BSNS. The patients, consisting of 15 females and 1 male with an average age of 48 years, were evaluated and/or treated at the institution. The article highlights the involvement of the nasal cavity or ethmoid sinuses in all tumors, with some cases demonstrating bone invasion and other complications. The patients underwent surgical resection, with some receiving adjuvant radiotherapy. At the time of the study, no patients had experienced local recurrence or progression, and none had experienced regional or distant metastases. The article also discusses the immunomarker and FISH analysis results, which were consistent with existing case studies. The study concludes that the disease course of BSNS may be indolent based on the outcomes observed in the patients treated at the institution. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, discusses two case reports of a rare malignancy called sinonasal lymphoepithelial carcinoma. The malignancy is associated with men in their fifth to seventh decades of life and is sometimes linked to the Epstein-Barr virus. Treatment options for this type of tumor vary and include surgery, chemotherapy, radiation therapy, or a combination of these. The authors present two cases and suggest that a treatment algorithm similar to that used for nasopharyngeal carcinoma may be effective for lymphoepithelial carcinoma. However, further research and more cases are needed to make stronger recommendations. [Extracted from the article]

Two patients with thyroid eye disease underwent inferomedial orbital decompression complicated by a cerebrospinal fluid (CSF) leak. One of the cases developed a postoperative pneumocephalus resolved with conservative measures. In the second case, the CSF leak was managed intraoperatively. In both patients, a computed tomography (CT) scan revealed a pronounced slope of the lateral lamella of the cribriform plate, forming an obtuse angle with its lateral bony extension. When this anatomical disposition of the olfactory fossa (OF) is present, the course of the anterior ethmoidal artery (AEA) is usually embedded in the skull base, and its foramen should not be taken as the upper limit of the transconjunctival ethmoidectomy. The shape and relative height of the olfactory fossa and fovea ethmoidalis, and the course of the AEA should always be assessed before transconjunctival medial decompressions. [ABSTRACT FROM AUTHOR]

Purpose: Understanding ethmoid roof morphology is crucial to prevent complications in endoscopic sinus surgery. This study aimed to evaluate the morphological properties of the ethmoidal roof regarding gender and age differences using Keros and Yenigun classifications on high-resolution computed tomography images. Methods: We retrospectively analyzed 891 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in coronal sections and the anterior–posterior length in axial planes. The study retrospectively examined CT images of paranasal sinuses of patients living in the eastern Anatolian region of Turkey. Results: In both Keros and Yenigun Classifications, the most common class was type 2, and the least common class was type 3. According to Keros et al.'s method, no significant difference was observed between men and women (p = 0.698). However, according to Yenigun et al., the average values of women in terms of the anterior–posterior distance of the ethmoid roof were significantly higher than men (p = 0.001). When examined according to age, a very low, negative correlation was revealed regarding Keros and Yenigun classifications (p = 0.047 and p < 0.001 retrospectively). According to Keros and Yenigun's classification, there was no significant difference between the left and right sides (p = 0.488 and p = 0.919, respectively). Conclusion: The morphological properties of the ethmoidal roof have importance to be considered for preoperative planning. Studying larger patient groups and meta-analyses that gather various research results about this subject might help better understand the ethmoidal roof morphology among populations. [ABSTRACT FROM AUTHOR]

In comparing the cranial base's size, most cephalometric studies focused on the length and angle in the anteroposterior direction. However, investigating the anterior, middle, and posterior cranial base's transverse dimensions is challenging. This study aimed to investigate the transverse dimensions of the cranial base in different craniofacial skeletal patterns and sexes using cone-beam computed tomography (CBCT). A total of 210 adults (105 males and 105 females), including three different skeletal relationships, were included in the study. The cranial base dimensions were measured on a three-dimensional image structure rendered by CBCT. Statistical methods included the Kappa statistic for analysis of consistency and reproducibility and the independent t -test for differences in cranial base dimensions between sexes. A general linear model (GLM) was used to compare the transverse size of the cranial base among skeletal Class I, II, and III groups. The Pearson correlation coefficient explored the correlation among the cranial base dimensions. The cranial base dimensions did not differ significantly between skeletal Class I, II, and III. The more prominent cranial base size was found in males than females, except for the crista galli length (CGL) and cribriform ethmoid plate width (CEPW). The cranial base dimensions did not differ significantly between different skeletal relationships. Most dimensions have significant correlations in the middle and the posterior cranial base. The cranial base's transverse dimensions in Taiwanese adults show no significant differences between craniofacial skeletal relationships. In the middle and posterior cranial base, transverse measurements reveal significant sexual dimorphism. [ABSTRACT FROM AUTHOR]

Introduction Prostate cancer is the second most common male cancer worldwide. Its rising incidence and high overtreatment rate drive the search for new prognostic factors. Histopathological variants, such as cribriform pattern (CP), are associated with poorer oncologic outcome. The aim of this study was to assess the correlation between CP in prostate biopsy and radical prostatectomy (RP) and postoperative pathological features. Material and methods In this retrospective, single-centre study we analysed the reviewed medical records of 100 men who underwent minimally invasive RP in the years 2017-2019. RP histopathological examination was performed by a single expert pathologist, and preoperative biopsies were assessed by various professionals from different referral centres. Results 48% of men underwent endoscopic RP with limited lymphadenectomy, whereas 52% underwent laparoscopic RP with extended lymphadenectomy. CP in biopsy was present in 6 patients: 3 in each of both groups (6.3% and 5.8%, respectively). Lymph node metastases were present in 50% and 10% of patients with and without CP in biopsy, respectively (p = 0.028). Postoperative histopathological examination revealed CP in 65%. CP in RP was associated with higher International Society of Urological Pathology (ISUP) (p < 0.001), extraprostatic extension (EPE) (p = 0.001), seminal vesicle invasion (SVI) (p = 0.001), and positive surgical margin (PSM) (p = 0.004). Thirteen (20%) of the patients with CP in the RP specimen had lymph node metastasis, and none of the patients without CP in the RP specimen had regional LN metastasis. Conclusions The presence of CP in a biopsy specimen and RP is associated with negative postoperative features. Therefore, efforts should be made to increase CP reporting in biopsies because its identification could trigger a more radical surgical approach with extended lymphadenectomy. [ABSTRACT FROM AUTHOR]

Introduction: Nose‐to‐brain (N2B) insulin delivery has potential for Alzheimer's disease (AD) therapy. However, clinical implementation has been challenging without methods to follow N2B delivery non‐invasively. Positron emission tomography (PET) was applied to measure F‐18‐labeled insulin ([18F]FB‐insulin) from intranasal dosing to brain uptake in non‐human primates following N2B delivery. Methods: [18F]FB‐insulin was prepared by reacting A1,B29‐di(tert‐butyloxycarbonyl)insulin with [18F]‐N‐succinimidyl‐4‐fluorobenzoate. Three methods of N2B delivery for [18F]FB‐insulin were compared – delivery as aerosol via tubing (rhesus macaque, n = 2), as aerosol via preplaced catheter (rhesus macaque, n = 3), and as solution via preplaced catheter (cynomolgus macaque, n = 3). Following dosing, dynamic PET imaging (120 min) quantified delivery efficiency to the nasal cavity and whole brain. Area under the time‐activity curve was calculated for 46 regions of the cynomolgus macaque brain to determine regional [18F]FB‐insulin levels. Results: Liquid instillation of [18F]FB‐insulin by catheter outperformed aerosol methods for delivery to the subject (39.89% injected dose vs 10.03% for aerosol via tubing, 0.17% for aerosol by catheter) and subsequently to brain (0.34% injected dose vs 0.00020% for aerosol via tubing, 0.05% for aerosol by catheter). [18F]FB‐insulin was rapidly transferred across the cribriform plate to limbic and frontotemporal areas responsible for emotional and memory processing. [18F]FB‐insulin half‐life was longer in olfactory nerve projection sites with high insulin receptor density compared to the whole brain. Discussion: The catheter‐based liquid delivery approach combined with PET imaging successfully tracked the fate of N2B [18F]FB‐insulin and is thought to be broadly applicable for assessments of other therapeutic agents. This method can be rapidly applied in humans to advance clinical evaluation of N2B insulin as an AD therapeutic. Highlights for: [18F]FB‐insulin passage across the cribriform plate was detected by PET.Intranasal [18F]FB‐insulin reached the brain within 13 min.[18F]FB‐insulin activity was highest in emotional and memory processing regions.Aerosol delivery was less efficient than liquid instillation by preplaced catheter.Insulin delivery to the cribriform plate was critical for arrival in the brain. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) of the central nervous system (CNS) is a lethal and incapacitating disease. Several studies have been performed to understand the mechanism of bacterial arrival to CNS, however, it remains unclear. Although the interaction of the host, the pathogen, and the environment trigger the course of the disease, in TB the characteristics of these factors seem to be more relevant in the genesis of the clinical features of each patient. We previously tested three mycobacterial clinical isolates with distinctive genotypes obtained from the cerebrospinal fluid of patients with meningeal TB and showed that these strains disseminated extensively to the brain after intratracheal inoculation and pulmonary infection in BALB/c mice. In this present study, BALB/c mice were infected through the intranasal route. One of these strains reaches the olfactory bulb at the early stage of the infection and infects the brain before the lungs, but the histological study of the nasal mucosa did not show any alteration. This observation suggests that some mycobacteria strains can arrive directly at the brain, apparently toward the olfactory nerve after infecting the nasal mucosa, and guides us to study in more detail during mycobacteria infection the nasal mucosa, the associated connective tissue, and nervous structures of the cribriform plate, which connect the nasal cavity with the olfactory bulb. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the olfactory fossa anatomy (Keros types) and its relationship with changes in adjacent anatomical structures using cone-beam computed tomography (CBCT). In this descriptive-analytical study, the paranasal CBCT of 120 healthy adults over 18 years of age were evaluated. The olfactory fossa depth on both sides and the degree of asymmetry on both sides were reported. Correlation of olfactory fossa depth with the size of adjacent anatomical structures such as middle concha length, maximum orbital height and distance from ethmoid roof to nasal floor and ethmoid roof height to the palate in the anterior and posterior, length, and lateral angle of the lamella and cribriform plate distance. The lower concha junction was examined. The most common olfactory fossae on both sides of the Keros classification were Type II, Type I, and Type III, respectively. The mean dimensions of adjacent anatomical structures on the right and left did not differ significantly. The length and lateral angle of the lamella and the height of the ethmoid roof to the floor of the nose, and the height of the ethmoid roof to the palate in the back, on the right, and left in Type III were greater. The lateral angle of the left lamella was greater in Type III. The relationship between olfactory fossa depth and changes in anatomical structures were not significantly correlated with increasing olfactory fossa depth. [ABSTRACT FROM AUTHOR]

Objectives Cerebrospinal fluid (CSF) leaks of the anterior cranial base are frequently repaired with endonasal, multilayered reconstructions. Vascularized tissue flaps are superior to free mucosal grafts and biomaterials in many cases. Limitations of previously described flaps include reach, rotation, pedicle availability, and postoperative sinonasal morbidity. The objective of this study is to describe the superiorly based middle turbinate flap, a novel vascularized mucosal reconstruction option, and to present a case series demonstrating flap utility. Design Cadaveric feasibility study with technical description and illustrative case series. Setting Tertiary medical center. Participants Three silicone-injected cadaveric specimens (6 sides); 7 patients with CSF rhinorrhea from bony dehiscence of the anterior cranial fossa repaired with a superiorly based middle turbinate flap. Outcome Measures Cadaveric feasibility, in vivo repair outcomes, sinonasal symptoms, and postoperative healing. Results Cadaveric dissection demonstrated a consistent vascular plexus arising from the anterior and posterior ethmoid arteries, originating at the superior attachment of the middle turbinate and traveling inferiorly to supply the mucosa of the middle turbinate. Mean surface area of the flap was 776.67 ± 114.60 mm 2. The clinical series of 7 patients involved leaks around the cribriform plate and fovea ethmoidalis. There were no instances of repair failure. All cases showed rapid and complete remucosalization without significant sinonasal morbidity. Conclusion The superiorly based middle turbinate flap is a reliable, versatile, and effective option for a vascularized mucosal flap onlay that can be used in anterior skull base reconstruction. This flap is particularly useful in the repair of defects involving the cribriform plate and fovea ethmoidalis. [ABSTRACT FROM AUTHOR]

Although several well-preserved crania are known for the Mesozoic Eutriconodonta, three-dimensional reconstructions of the character-rich inner ear and basicranial region based on high-resolution computed tomography scans have previously only been published for the Late Jurassic Priacodon. Here we present a description of the petrosal and inner ear morphology of a triconodontid eutriconodontan from the Lower Cretaceous Cloverly Formation, which we provisionally assign to Astroconodon. The bony labyrinth of Astroconodon is plesiomorphic for mammaliaforms in lacking a primary osseous lamina, cribriform plate, and osseous cochlear ganglion canal. However, as in Priacodon and the zhangheotheriid Origolestes, Astroconodon has a secondary osseous lamina base that extends nearly the complete length of the cochlear canal. The cochlear canal is straighter in Astroconodon and other eutriconodontans compared to several basal mammaliaform clades (e.g., morganucodontans, docodontans), that exhibit varying degrees of cochlear canal curvature. The pars cochlearis of the petrosal was well vascularized in Astroconodon, exhibiting a network of venous canals that crossed the cochlea transversely on its ventral and dorsal aspects. Of particular note are several canals that passed along the base of the secondary osseous lamina. As in Priacodon and Origolestes, those canals do not show the extensive connections to the cochlear labyrinth as seen in the basal mammaliaforms Morganucodon and Borealestes. The inner ear of Astroconodon thus highlights the complex history of the mammaliaform cochlear canal, in which different clades appear to follow independent evolutionary trajectories and various key morphological features (e.g., cochlear canal length, curvature, vascularization and osseous supports for the basilar membrane) exhibit considerable homoplasy. [ABSTRACT FROM AUTHOR]

Background: Stereotactic radiotherapy (SRT) is an emerging treatment for sinonasal tumors in dogs. Reported results regarding tumor control and incidence of acute and late radiation morbidities are inconsistent. Objectives: To determine treatment efficacy and prognostic indicators of SRT in dogs with sinonasal tumors and to quantify acute and late radiation morbidities. Animals: One hundred and eighty‐two client‐owned dogs with sinonasal tumors diagnosed cytologically, histologically, or radiographically that underwent SRT. Methods: Single‐arm retrospective study by reviewing medical records of dogs treated with SRT (10 Gy × 3) between 2010 and 2015. Kaplan‐Meier analysis was used to determine overall survival (OST; from the first day of SRT to death by any cause) and disease‐specific survival times (DSST; OST but censoring tumor/treatment‐unrelated death). Tumors were staged using modified Adams criteria. Results: Median OST and DSST of dogs treated with 1 course of SRT was 441 (95% CI: 389‐493 days) and 482 (428‐536 days) days, respectively with skin/oral cavity acute morbidities observed in 3% of dogs. DSST in dogs with stage 4 disease showed no statistical difference compared to other stages (P =.64). Oro‐nasal (n = 2) or naso‐cutaneous (n = 11) fistula development occurred in 7.1% of dogs with median time of 425 days (range: 83‐1733 days). Possible chronic rhinitis after SRT was recorded in 54 of 88 dogs (61%) where information was available. Conclusions and Clinical Importance: Results are comparable to other reports of treatment of SRT. Acute morbidities were minimal. Modified Adams stage scheme appeared to be inappropriate for prognostication for dogs with sinonasal tumors treated with SRT. [ABSTRACT FROM AUTHOR]

Progress in skull-base endoscopic surgery has improved our knowledge of olfactory cleft (OC) anatomy. This article presents a review of current knowledge concerning the OC roof: descriptive anatomy, radiological exploration, and endoscopic observation. The OC is a narrow area in the most superior part of the nasal cavity. Its roof is the thinnest structure separating the nasal cavities from the brain; it comprises three superimposed tissues: nasal mucosa, ethmoid cribriform plate (ECP), and dura mater. The ECP comprises the anterior ECP containing the ethmoidal slit (ES) medially and the cribroethmoidal foramen (CEF) laterally; and the posterior ECP, comprising the olfactory foramina. The OC roof is bordered anteriorly by the nasal bone roof, laterally by the lateral ethmoid masses, and posteriorly by the jugum and anterior wall of the sphenoid sinuses. Imaging is crucial for analyzing this wall, providing precise detailed information on conformation and anatomic relations with adjacent structures such as the anterior ethmoidal artery. Understanding OC roof anatomy and correct interpretation of imaging are essential for safety in present-day functional endoscopic sinus surgery and anterior skull-base oncologic surgery. [ABSTRACT FROM AUTHOR]

Distinct patterns of local infiltration are a common feature of canine oligodendroglioma and astrocytoma, and typically involve the surrounding neuroparenchyma, ventricles, or leptomeninges. Infiltration of adjacent extraneural sites is rare and has not been well documented in veterinary medicine. Here we describe 6 canine gliomas with cribriform plate involvement (compression or infiltration) and caudal nasal invasion confirmed by neuroimaging, autopsy, and/or histology. All affected dogs were adults (9–12-y-old), and 3 were brachycephalic. Clinical signs were associated with the brain tumor, with no respiratory signs reported. Magnetic resonance imaging in 2 patients revealed a rostral intraparenchymal telencephalic mass with extension into the cribriform plate. All dogs were euthanized. Gross changes consisted of poorly demarcated, white or pale-yellow, soft, and, in oligodendrogliomas, gelatinous, intraparenchymal masses that expanded the rostral portions of the telencephalon and adhered firmly to the ethmoid bone and cribriform plate. Gliomas were classified as high-grade oligodendrogliomas (4 cases) and high-grade astrocytomas (2 cases) based on histology and immunohistochemistry for OLIG2 and GFAP. In all cases, there was evidence of cribriform plate invasion and, in one case, additional invasion of the caudal nasal cavity. [ABSTRACT FROM AUTHOR]

Background: Skull base (SB) injuries happens mostly either in the thinnest or the least resistant part of skull base. The lateral lamella of cribriform plate is one of the common sites of injury during endoscopic anterior skull base surgeries. The anterior ethmoidartery (AEA) visualization is considered as a significant anatomical landmark in such surgeries. Studies correlating their positional relation with morphology of olfactory fossa remain limited. This study aims to look into the relation of AEA to that of SB in different types of olfactory fossa morphology. Materials and methods: A surveying radiological study was conducted on 90 coronal CT images from patients who were exposed to paranasal CT imaging in a tertiary care teaching hospital. The examination included all CT images as well as an indication of sinusitis. The exclusion being changed skull base anatomy as a result of previous surgical intervention, injury, or tumour, and age less than 18 years. RadiAnt Dicom viewer was used to inspect the images. [8] The position of AEA in relation to SB was identified in the bone window of coronal CT scans. On each side, it was divided as at SB or below SB. the longitudinal distance from AEA to SB was evaluated separately. Depending up on the distance of AEA from SB, 3 groups were sectioned as follows: set A - < 2.5 mm, set B – 2.5 to 5 mm and set C - > 5 mm. Result: In our present study of 90 patients, number of male patient was 58 (64.4%) whereas number of female patient was 32 (35.6%) [Table 1]. Age of patient was from 18 years to 80years. anterior ethmoidal artery canal was seen in 30% (27) scan. Most of those were complete type. Anterior ethmoidal foramen was seen in 90% (81) of CT scan. Supraorbital pneumatisation was seen in 40% (36) scan [Table 2]. Conclusion: It was concluded that notch which was present in the medial wall of orbit was a very good landmark to locate anterior ethmoidal artery and it was found in 98% of cases and in 28% of CT scan supraorbital pneumatisation was found which has a very close relationship with visualization of anterior ethmoidal artery canal. [ABSTRACT FROM AUTHOR]

Background: Cryptococcus is one of the most common systemic mycosis worldwide, infecting young adults of the large to giant breed dogs. Infection is commonly acquired from the environment via the sinonasal cavity as the main portal of entry. It either remains there, or spreads to the central nervous system (CNS) and the eye (optic nerve and retina) by penetration of the cribriform plate, or haematogenously to other viscera. Lung involvement is uncommon in cats and dogs in contrast to human and equine patients. Whilst there is a wide genetic diversity amongst Cryptococcus neoformans and Cryptococcus gattii isolates along the West Coast and Northern parts of Australia, the molecular diversity of C. gatti is considered very low on the East Coast of Australia, with a huge preponderance of VGI cases. We report on a young small breed brachycephalic dog that presented with extreme gastrointestinal and respiratory signs, but no CNS involvement. It is the first reported case of C. gattii VGII genotype in a companion animal from Queensland. Case Report: A 9‐month old female entire French Bulldog presented initially for diarrhoea. Clinical progression was accompanied by the development of respiratory signs, so the patient was referred to a 24 h care facility. Following hospitalisation, the patient became hypoxemic requiring mechanical ventilation. A bronchoalveolar lavage performed antemortem confirmed abundant Cryptococcal spp. Further culturing and genotyping identified the species as Cryptococcus gattii VGII. Post‐mortem findings indicated gross gastrointestinal and mesenteric involvement, with possible dissemination to the local mesenteric lymph node and lungs. Conclusion: This case describes a rare example of a Cryptococcus spp suspected of disseminating from the gastrointestinal tract to the lungs, without involvement of the CNS. The observation of this finding in a small brachycephalic breed is unusual, and the finding of genotype VGII on the East Coast of Queensland is extremely unusual as there is no prior travel history of the dog or owners. The presence of a miliary lung pattern with primary gastrointestinal disease in a small breed dog warrants adding cryptococcosis to the differential diagnosis. [ABSTRACT FROM AUTHOR]

Esthesioneuroblastoma is a tumor arising from olfactory neuroepithelium with an incidence of four per million. This case presents a rare nasal cavity neoplasm with hemorrhagic properties that may lead to significant sequelae. We present a 69-year-old male patient who presented with worsening altered mental status over the past 6-7 months. His Glasgow coma scale was a nine, showing a large mass centered at the cribriform plate with extension intracranially, sinonasal cavity, and bilateral orbits on diagnostics. Bifrontal craniotomy was performed one day after admission with resection of the tumor in the cranial fossa and intranasally, and decompression of the brainstem, frontal lobes, and third ventricle. After surgery, the patient was managed in the intensive care unit but continued to deteriorate. He was confirmed to have no meaningful brain activity and eventually deceased seven days after admission. Depending on the tumor stage, esthesioneuroblastoma can have a favorable prognosis with proper therapies. Different surgical techniques for ENB lead to the question of which therapeutic modality is the best because of the tumor’s gross hemorrhagic properties. With adjunctive radiation therapy and/or chemotherapy, more research can bring light to proper surgical techniques. [ABSTRACT FROM AUTHOR]

Background: Traditional management of olfactory neuroblastoma (ONB) includes margin‐negative resection with removal of cribriform plate, dura, and olfactory bulb, regardless of intracranial disease. This approach may be overtreating certain patients. Our investigation examines risk factors associated with occult intracranial disease to optimize therapeutic outcomes. Methods: This retrospective, multi‐institutional cohort study examined clinical covariates associated with occult intracranial involvement. Patient demographics, staging, Hyam's grade, and pathologic involvement of dura, olfactory bulb/tract, and brain were collected. Diagnostic imaging was reviewed. Positive and negative predictive value (NPV) were estimated along with effect size estimates. Cox hazard regression examined associations with overall survival (OS) and disease‐free survival (DFS). Results: A total of 224 subjects with new diagnoses of ONB (2005–2021) were identified. Skull base bone involvement on computed tomography (CT) had the highest NPV for pathologic dura (88.0%), olfactory bulb (88%), and brain involvement (97.3%). Hyam's grade category was significantly associated with dural involvement (φC = 0.26; 95% confidence interval [CI]: 0.16, 0.42). Subjects without radiologic skull base involvement (n = 66) had pathologic positivity of 12.1%. Within this subgroup, Hyam's grade was clinically significant for dural positivity (φ = 0.34; 95% CI: −0.12, 0.71) with 28.6% involvement in high grade tumors. Neither clinical nor pathologic positivity of intracranial structures were associated with significantly different OS or DFS. Conclusions: Both CT and magnetic resonance imaging (MRI) had reasonably good NPV for involvement of dura and olfactory bulb. Higher Hyam's grade was associated with dural involvement. Patients with low‐grade tumors not involving the skull base may be suitable for avoiding skull base resection; however, further investigation is warranted. [ABSTRACT FROM AUTHOR]

Abstract Introduction Nose‐to‐brain (N2B) insulin delivery has potential for Alzheimer's disease (AD) therapy. However, clinical implementation has been challenging without methods to follow N2B delivery non‐invasively. Positron emission tomography (PET) was applied to measure F‐18‐labeled insulin ([18F]FB‐insulin) from intranasal dosing to brain uptake in non‐human primates following N2B delivery. Methods [18F]FB‐insulin was prepared by reacting A1,B29‐di(tert‐butyloxycarbonyl)insulin with [18F]‐N‐succinimidyl‐4‐fluorobenzoate. Three methods of N2B delivery for [18F]FB‐insulin were compared – delivery as aerosol via tubing (rhesus macaque, n = 2), as aerosol via preplaced catheter (rhesus macaque, n = 3), and as solution via preplaced catheter (cynomolgus macaque, n = 3). Following dosing, dynamic PET imaging (120 min) quantified delivery efficiency to the nasal cavity and whole brain. Area under the time‐activity curve was calculated for 46 regions of the cynomolgus macaque brain to determine regional [18F]FB‐insulin levels. Results Liquid instillation of [18F]FB‐insulin by catheter outperformed aerosol methods for delivery to the subject (39.89% injected dose vs 10.03% for aerosol via tubing, 0.17% for aerosol by catheter) and subsequently to brain (0.34% injected dose vs 0.00020% for aerosol via tubing, 0.05% for aerosol by catheter). [18F]FB‐insulin was rapidly transferred across the cribriform plate to limbic and frontotemporal areas responsible for emotional and memory processing. [18F]FB‐insulin half‐life was longer in olfactory nerve projection sites with high insulin receptor density compared to the whole brain. Discussion The catheter‐based liquid delivery approach combined with PET imaging successfully tracked the fate of N2B [18F]FB‐insulin and is thought to be broadly applicable for assessments of other therapeutic agents. This method can be rapidly applied in humans to advance clinical evaluation of N2B insulin as an AD therapeutic. Highlights for [18F]FB‐insulin passage across the cribriform plate was detected by PET. Intranasal [18F]FB‐insulin reached the brain within 13 min. [18F]FB‐insulin activity was highest in emotional and memory processing regions. Aerosol delivery was less efficient than liquid instillation by preplaced catheter. Insulin delivery to the cribriform plate was critical for arrival in the brain.