Embryonic development and cranial ossification of the Japanese Aodaisho, Elaphe climacophora (Serpentes: Colubridae): with special reference to the prootic bone and auditory evolution in snakes.

Snakes show remarkably deviated "body plan" from other squamate reptiles. In addition to limb loss, they have accomplished enormous anatomical specialization of the skull associated with the pit organs and the reduction of the tympanic membranes and auditory canals in the outer ears. Despite being the most diverse group of snakes, our knowledge of the embryonic staging for organogenesis and cranial ossification has been minimal for Colubridae. Therefore, in the present observation, we provide the first embryonic description of the Japanese rat snake Elaphe climacophora. We based our study on the Standard Event System (SES) for external anatomical characters and on a description of the cranial ossification during post-ovipositional development. We further estimated the relative ossification timing of each cranial bony element and compared it with that of selected other snakes, lizards, turtles, and crocodilians. The present study shows that the relative ossification timing of the palatine and pterygoid bones is relatively early in squamates when compared to other reptiles, implying the developmental integration as the palate-pterygoid complex in this clade and functional demands for the unique feeding adaptation to swallow large prey with the help of their large palatine and pterygoid teeth. Furthermore, unlike in species with pit organs, the prootic bone of Ela. climacophora is expanded to provide articulation with the supratemporal, thereby contributing to the hearing system by detecting substrate vibration. We also demonstrate that the relative timing of the prootic ossification is significantly accelerated in colubrids compared to snakes with pit organs. Our finding suggests that the temporal changes of the prootic ossification underpin the evolution of the perception of the ground-bourne sound signals among snakes.

Craniocervical Morphometry in Pomeranians-Part I: Intra-Observer, Interobserver, and Intermodality (CT vs. MRI) Agreement.

BACKGROUND: Currently, there are no diagnostic imaging-based studies that have focused specifically on the craniocervical morphology of Pomeranian dogs in relation to Chiari-like malformation and syringomyelia (CM/SM). The aims of Part I of this two-part study are to assess the intra-observer, interobserver, and intermodality reliability and agreement for various aspects of the craniocervical morphology of Pomeranians with and without CM/SM. METHODS: Prospectively, Pomeranians were included that underwent both CT and MRI studies of the head and cervicothoracic vertebral column. Two observers (experienced and novice) independently performed CM and SM classifications, qualitative assessments, and quantitative measurements. The experienced observer performed these assessments twice. A third observer (experienced) performed CM and SM normal or abnormal classifications. RESULTS: Ninety-nine (99) dogs were included. Interobserver reliability was influenced by observer experience level. For the experienced versus novice observers, substantial interobserver agreement was found for classification of SM as normal or abnormal (Cohen's kappa = 0.63), while interobserver agreement was fair for classification of SM as normal or abnormal (Cohen's kappa = 0.31). Interobserver, intra-observer, and intermodality reliability were variable for different measurements and assessments, and best overall for the CT-based measurements. CONCLUSIONS: Interobserver reliability and agreement results should be taken into account in the evaluation of results of future studies as well as the evaluation of imaging studies of Pomeranians presented clinically.

Craniocervical Morphometry in Pomeranians-Part II: Associations with Chiari-like Malformation and Syringomyelia.

BACKGROUND: The aim of Part II of this two-part study is to describe and analyze the association of various aspects and measurements related to the morphometry of the skull and craniocervical region to CM/SM status of Pomeranians, by means of computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: Prospectively, Pomeranians were included that underwent both CT and MRI studies of the head and cervicothoracic vertebral column. For those cases where qualitative classifications differed between observers, the experienced observer re-evaluated the studies and decided on a final classification that was used for further analysis. For quantitative measurements, the means of the observers' measurements were used for analysis. RESULTS: Among statistically significant differences in measurements, we found that dogs with SM had a significantly shorter clivus length based on both MRI (p = 0.01) and CT measurements (p = 0.01), and a significantly smaller caudal cranial fossa area based on both MRI (p = 0.02) and CT measurements (p = 0.02). CONCLUSIONS: Significant morphometrical differences were identified between dogs with or without CM/SM. The findings in this study add to those already described in other breeds and provide further insight into factors that may play a role in the pathogenesis of CM/SM in Pomeranians.

Assessing the Effectiveness of Modified Tibial Plateau Leveling Osteotomy Plates for Treating Cranial Cruciate Ligament Rupture and Medial Patellar Luxation in Small-Breed Dogs.

In small-breed dogs with concurrent cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL), correcting both disorders is are essential for restoring normal gait. However, the previously described surgical treatment, using two osteotomy technique, poses a high risk of fracture and instability. Addressing CCLR and MPL with a single osteotomy and implant was considered superior to the conventional method. Therefore, a pre-contoured modified tibial plateau leveling osteotomy (PCM-TPLO) plate facilitating medial shifting of the proximal tibia was developed. We compared postoperative alignment and strength between this novel plate group and a conventional tibial plateau leveling osteotomy (TPLO) plate group using eight small-breed dog cadavers each. Additionally, we investigated the potential of the novel plate as an alternative to tibial tuberosity transposition. Postoperative alignment and strength were assessed through radiographs and mechanical testing. Measurements including tibial plateau angle, mechanical medial proximal tibial angle, and number of screws within the joint were also analyzed. There were no significant differences in all measured parameters. For the novel plate, the medial displacement ratio of the proximal tibia was confirmed to be approximately 30%, and the result was thought to be appropriate. These findings suggest that the PCM-TPLO plate could be a promising alternative for treating concurrent CCLR and MPL in small-breed dogs.

Clinical and Genomic Profile of Primary Cranial Neurolymphomatosis.

Primary cranial neurolymphomatosis (PCNL) is a rare subtype of primary CNS lymphoma (PCNSL) in which infiltrative lymphomatous involvement is confined to cranial nerves. Here, we report a case of PCNL with successful genomic profiling. A 57-year-old male had a lengthy prediagnostic phase spanning approximately 30 months, characterized by multiple episodes of cranial neuropathies managed by steroids. At the time of diagnosis, the patient had right-sided cranial neuropathies involving cranial nerves (CN) V, VI, and VII. Pathological findings of the right cavernous lesion biopsy were consistent with large B-cell lymphoma-infiltrating nerve fibers. The clinical course was aggressive and refractory, characterized by relentless progression with the development of cervical spinal neurolymphomatosis, cerebrospinal fluid involvement, and ependymal and intraparenchymal cerebral involvement, despite multiple lines of therapy, including chemoimmunotherapy, Bruton's tyrosine kinase inhibitor, radiation, autologous stem cell transplant, chimeric antigen receptor T-cell therapy (CAR-T), and whole-brain radiation. The patient survived for 22 months from the time of the initial diagnosis and 52 months after the first episode of cranial neuropathy. Next-generation sequencing identified mutations (MYD88, CD79b, and PIM1) that are frequently observed in PCNSL. The unusual findings included a total of 22 mutations involving PIM1, indicating a highly active aberrant somatic hypermutation and two missense CXCR4 mutations. CXCR4 mutations have never been described in PCNSL and may have implications for disease biology and therapeutic interventions. We provide a literature review to further elucidate PCNL.

Craniosynostosis: orofacial and oral health perspectives with masticatory insights.

BACKGROUND: Craniosynostosis (CS), premature fusion of one or more cranial sutures, leads to abnormal skull development, impacting both facial esthetics and oral function. This study aimed to evaluate the specific orofacial and oral health characteristics, including masticatory performance, in Thai patients with CS. METHODS: A comparative study was conducted with Thai CS patients aged 6-17 years and a control group of healthy individuals with similar age distribution. Assessments included craniofacial morphology, oral health status, and masticatory performance. Intergroup comparisons utilized appropriate statistical tests. RESULTS: The study included 24 CS patients with a mean age of 10.11 ± 2.98 years and 30 controls. CS patients exhibited a significantly higher prevalence of various oral conditions compared to controls: cleft palate (20.8%), anterior open bite (41.7%), anterior crossbite (54.2%), posterior crossbite (50%), combined anterior-posterior crossbite (45.8%), dental crowding in both maxilla and mandible (50% and 45.8% respectively), congenitally missing teeth (50%), supernumerary teeth (12.5%), and eruption failure (54.2%). Furthermore, CS patients exhibited significantly higher caries prevalence and susceptibility, alongside poorer oral hygiene, compared to controls. Regarding jaw relationships, CS patients exhibited a significantly higher proportion of Angle's Class III malocclusion (50%) compared to the control group, where Class I malocclusion was predominant (50%). Masticatory performance, assessed using the two-color gum mixing ability test, showed significantly higher hue variance in CS patients (0.12 ± 0.07) compared to the control group, indicating reduced chewing performance. CONCLUSION: This study underscores the significant orofacial and oral health challenges faced by children with CS, including a high prevalence of malocclusions, dental anomalies, elevated caries experience, and compromised masticatory function. These findings emphasize the importance of tailored interventions and comprehensive oral healthcare strategies to address the unique needs of this population and improve their overall quality of life.

Unilateral alacrimia as a presenting symptom of Meckel's cave tumour.

Meckel's cave tumour, a rare benign tumour originating from the Schwann cells surrounding the trigeminal nerve within the Meckel's cave region, can present with a variety of clinical manifestations. We report a case of a 44-year-old male patient who presented with symptoms of tear deficiency, including dryness, ocular discomfort, and blurred vision. Diagnostic evaluation revealed the presence of a Meckel's cave tumour harming the trigeminal nerve, leading to alacrimia. This case highlights the association between Meckel's cave tumour and tear deficiency disorders.

Outcomes and Factors Associated with Successful Strabismus Surgery for Abducens Nerve Palsies: A Retrospective Study and Literature Review.

Purpose: Several studies reported surgical outcomes for abducens nerve palsy, but information on factors that affect treatment success remains lacking. These factors are crucial for developing a treatment plan and providing disease counseling. This study aimed to investigate the outcomes of strabismus surgery for abducens nerve palsy and determine the factors that influence its success, including a review of relevant literature. Methods: This retrospective analysis included abducens nerve palsy cases, focusing on surgical interventions and relevant patient data, at the outpatient clinics of Phramongkutklao Hospital from April 1, 2012, to April 30, 2022. A relevant literature review included the surgical success rate and factors that influence surgical outcomes. Results: This study enrolled 32 patients, including 19 with partial and 13 with complete abducens nerve palsy. The overall success rate of strabismus surgery was 78.1%. Trauma was the leading cause of abducens nerve palsy in this population (28.13%). Fisher's exact and Mann-Whitney U-tests revealed that shorter abducens nerve palsy onset and smaller preoperative angle were significantly associated with successful surgical outcomes of strabismus surgery among the groups. In contrast, subgroup analysis revealed that only preoperative smaller angles were significantly associated with good surgical outcomes in horizontal strabismus surgery. However, the vertical rectus muscle transposition group demonstrated no significant factors. The literature review revealed that the success rate of surgery in abducens nerve palsy was 25%-82.6% for horizontal rectus muscle surgery and 46.2%-91% for rectus muscle transposition. Conclusion: The surgical success rate for abducens nerve palsy reached 78.1%, including 78.95% for partial and 76.92% for complete abducens nerve palsy. Notably, a shorter onset preceding surgery and a smaller preoperative angle significantly correlated with successful surgical outcomes one year postoperatively.

Numerous studies have been conducted to determine the effectiveness of eye muscle surgery for abducens nerve palsy. However, there is still a lack of information on the various factors that can influence the success rate of the treatment. Understanding these factors is crucial for developing appropriate treatment plans and guidance for individuals with this condition. Our study aimed to examine the effectiveness of strabismus surgery for abducens nerve palsy and identify the factors that affect its success. This was achieved by reviewing relevant literature and analyzing cases from Phramongkutklao Hospital between April 1, 2012, and April 30, 2022. We included 32 patients with partial or complete abducens nerve palsy, with trauma being the leading cause of the condition in our group. The results showed that the surgery was successful in 78.1% of cases. Our analysis revealed that getting surgery sooner after the palsy started and having a smaller misalignment angle before surgery were associated with better outcomes. However, these factors only mattered for horizontal eye muscle surgery, not vertical muscle transposition. Previous studies have reported success rates for this condition ranging from 25% to 91%. Our study concludes that earlier surgery and certain preoperative factors can improve outcomes for individuals with abducens nerve palsy after eye muscle surgery.

FBLN2 is associated with Goldenhar syndrome and is essential for cranial neural crest cell development.

Goldenhar syndrome, a rare craniofacial malformation, is characterized by developmental anomalies in the first and second pharyngeal arches. Its etiology is considered to be heterogenous, including both genetic and environmental factors that remain largely unknown. To further elucidate the genetic cause in a five-generation Goldenhar syndrome pedigree and exploit the whole-exome sequencing (WES) data of this pedigree, we generated collapsed haplotype pattern markers based on WES and employed rare variant nonparametric linkage analysis. FBLN2 was identified as a candidate gene via analysis of WES data across the significant linkage region. A fbln2 knockout zebrafish line was established by CRISPR/Cas9 to examine the gene's role in craniofacial cartilage development. fbln2 was expressed specifically in the mandible during the zebrafish early development, while fbln2 knockout zebrafish exhibited craniofacial malformations with abnormal chondrocyte morphologies. Functional studies revealed that fbln2 knockout caused abnormal chondrogenic differentiation, apoptosis, and proliferation of cranial neural crest cells (CNCCs), and downregulated the bone morphogenic protein (BMP) signaling pathway in the zebrafish model. This study demonstrates the role of FBLN2 in CNCC development and BMP pathway regulation, and highlights FBLN2 as a candidate gene for Goldenhar syndrome, which may have implications for the selection of potential screening targets and the development of treatments for conditions like microtia-atresia.

3D Printing for Customized Bone Reconstruction in Spheno-Orbital Meningiomas: A Systematic Literature Review and Institutional Experience.

Background: The treatment of spheno-orbital meningiomas (SOMs) requires extensive bone resections, creating significant defects in a complex geometrical space. Bone reconstruction represents a fundamental step that optimizes long-term aesthetic and functional outcomes. In recent years, 3D printing technology has also been exploited for complex skull base reconstructions, but reports remain scarce. Methods: We retrospectively analyzed four consecutive patients who underwent SOM resection and one-step 3D PEEK customized reconstruction from 2019 to 2023. A systematic review of 3D printing customized implants for SOM was then performed. Results: All patients underwent a frontotemporal craniotomy, removal of SOM, and reconstruction of the superolateral orbital wall and pterional region. The aesthetic outcome was extremely satisfactory in all cases. No orbital implant malposition or infectious complications were documented. Eleven papers were included in the literature review, describing 27 patients. Most (23) patients underwent a single-stage reconstruction; in three cases, the implant was positioned to correct postoperative delayed enophthalmos. Porous titanium was the most used material (16 patients), while PEEK was used in three cases. Prosthesis malposition was described in two (7.4%) patients. Conclusions: Single-step reconstruction with a personalized 3D PEEK prosthesis represents a valid reconstruction technique for the treatment of SOMs with good aesthetic outcomes.

Soft Tissue Dissection in the Transcondylar Approach: A Modified Layered Technique to Maximize Lateral Access.

Objective While the transcondylar approach is technically challenging, it provides generous ventral and caudal exposure to the craniovertebral junction. This approach requires navigation around multiple eloquent neurovascular structures including the lower cranial nerves, vertebral artery and its branches, and the brainstem. Superficial exposure, including incision location and muscle dissection, can dramatically affect the surgical angle and maneuverability at depth. Methods We demonstrate the transcondylar approach in a step-by-step fashion in a formalin-embalmed, latex-injected cadaver head. Dissection within each layer of the suboccipital muscles was performed. A small cohort with an illustrative case is also included herein. Results The sternocleidomastoid (SCM) muscle was retracted anteriorly; the splenium capitis, semispinalis capitis, and longissimus capitis muscles were disconnected from the superior nuchal line and reflected inferomedially. The suboccipital muscle group was fully exposed. The superior and inferior oblique muscles were disconnected from the transverse process of C1. The superior oblique and the rectus capitis posterior major muscles were then dissected off the inferior nuchal line, and the suboccipital muscle group was retracted inferomedially en bloc . The greater auricular nerve was retracted laterally with the SCM, and the greater occipital nerve was retracted inferomedially with the suboccipital muscle group. Conclusion This technique avoids the obstructive muscle bulk that results from a myocutaneous approach while maximizing deep exposure. Understanding the detailed muscular anatomical relationship with the insertion location and suboccipital nerves is key to complete and safe extracranial dissection. Diligent dissection helps minimize postoperative pain and muscle spasm while optimizing the closure technique.

Initial United States experience with Medtronic Stealth Autoguide cranial robotic guidance platform.

OBJECTIVE: Stereotactic techniques play an important role in neurosurgery. The development of a miniaturized cranial robot with an efficient workflow and accurate surgical execution is an important step in a broader application of these techniques. Herein, the authors describe their experience with the Medtronic Stealth Autoguide miniaturized cranial robot. METHODS: A retrospective review of 75 cases from 2020 to 2022 was performed. The patients who had undergone surgery utilizing the Stealth Autoguide robot were analyzed for surgical indication and accuracy, operative time, and clinical outcome. The outcomes were defined as follows: for stereoelectroencephalography (SEEG), the electrode placement pattern that identified the seizure focus and did not require any revision or additional leads; for biopsy, the percentage of cases in which diagnostic tissue was obtained; and for laser interstitial thermal therapy (LITT), the percentage of cases in which laser fiber placement was adequate for ablation. Surgical complications were defined as any asymptomatic or symptomatic intracerebral hemorrhage, new neurological deficit, or need for electrode, laser fiber, or biopsy needle repositioning or revision. RESULTS: The Stealth Autoguide robot was utilized in 75 on-label cases, including 40 SEEG cases for seizure focus localization, 19 LITT cases, and 16 stereotactic biopsy cases. The mean real target error (RTE) at the entry was 1.48 ± 0.84 mm for biopsy, 1.36 ± 0.89 mm for Visualase laser fiber placement, and 1.24 ± 0.72 mm for SEEG. The mean RTE at the target was 1.56 ± 0.95 mm for biopsy needle placement, 1.42 ± 0.93 mm for Visualase laser fiber placement, and 1.31 ± 0.87 mm for SEEG electrode placement. The surgical time for unilateral SEEG cases took an average 52 minutes (average 6.5 mins/lead, average 8 electrodes). Bilateral SEEG cases took an average 105 minutes (average 7.5 mins/lead, average 14 electrodes). In the SEEG population, there were no revised or unsuccessful seizure localizations. For biopsy, diagnostic tissue was obtained in 100% of cases. For LITT, fiber placement was adequate for ablation in 100% of cases. There were no cases of symptomatic or asymptomatic intracerebral hemorrhage, and no cases required repositioning or replacement of the laser fiber, electrode, or biopsy needle. One patient experienced transient cranial nerve III palsy following laser ablation that resolved in 10 weeks. A failure of communication between the robotic platform and the Stealth Autoguide as a station required the cancellation of 1 procedure. CONCLUSIONS: The Medtronic Stealth Autoguide robot system is versatile across biopsy, SEEG, and laser ablation indications. Setup and surgical execution are efficient with a high degree of accuracy and consistency.

Headbutting through time: A review of this hypothesized behavior in "dome-headed" fossil taxa.

Headbutting is a combative behavior most popularly portrayed and exemplified in the extant bighorn sheep (Ovis canadensis). When behaviorally proposed in extinct taxa, these organisms are oft depicted Ovis-like as having used modified cranial structures to combatively slam into one another. The combative behavioral hypothesis of headbutting has a long and rich history in the vertebrate fossil literature (not just within Dinosauria), but the core of this behavioral hypothesis in fossil terrestrial vertebrates is associated with an enlarged osseous cranial dome-an osteological structure with essentially no current counterpart. One confounding issue found in the literature is that while the term "headbutting" sounds simplistic enough, little terminology has been used to describe this hypothesized behavior. And pertinent to this special issue, potential brain trauma and the merits of such proposed pugilism have been assessed largely from the potential deformation of the overlying osseous structure; despite the fact that extant taxa readily show that brain damage can and does occur without osteological compromise. Additionally, the extant taxa serving as the behavioral counterpart for comparison are critical, not only because of the combative behaviors and morphologies they display, but also the way they engage in such behavior. Sheep (Ovis), warthogs (Phacochoerus), and bison (Bison) all engage in various forms of "headbutting", but the cranial morphologies and the way each engages in combat is markedly different. To hypothesize that an extinct organism engaged in headbutting like an extant counterpart in theory implies specific striking:contacting surfaces, speed, velocity, and overall how that action was executed. This review examines the history and usage of the headbutting behavioral hypothesis in these dome-headed fossil taxa, their respective extant behavioral counterparts, and proposes a protocol for specific behavioral terms relating to headbutting to stem future confusion. We also discuss the disparate morphology of combative cranial structures in the fossil record, and the implications of headbutting-induced brain injury in extinct taxa. Finally, we conclude with some potential implications for artistic reconstructions of fossil taxa regarding this behavioral repertoire.

Magnetic Resonance Imaging-Related Anatomic and Functional Parameters for the Diagnosis and Prognosis of Chiari Malformation Type I: A Systematic Review and Meta-analysis.

OBJECTIVE: Imaging parameters of Chiari malformation type I (CMI) development are not well established. This study aimed to collect evidence of general or specific imaging measurements in patients with CMI, analyze indicators that may assist in determining the severity of CMI, and guide its diagnosis and treatment. METHODS: A comprehensive search was conducted across various databases including the Cochrane Library, PubMed, MEDLINE, Scopus, and Embase, covering the period from January 2002 to October 2023, following predefined inclusion criteria. Meta-analyses were performed using RevMan (ver. 5.4). We performed a quantitative summary and systematic analysis of the included studies. This study was registered in the PROSPERO (International Prospective Register of Systematic Reviews) prior to initiation (CRD42023415454). RESULTS: Thirty-three studies met our inclusion criteria. The findings indicated that out of the 14 parameters examined, 6 (clivus length, basal angle, Boogard's angle, supraocciput lengths, posterior cranial fossa [PCF] height, and volume) exhibited significant differences between the CMI group and the control group. Furthermore, apart from certain anatomical parameters that hold prognostic value for CMI, functional parameters like tonsillar movement, obex displacement, and cerebrospinal fluid dynamics serve as valuable indicators for guiding the clinical management of the disease. CONCLUSION: We collated and established a set of linear, angular, and area measurements deemed essential for diagnosing CMI. However, more indicators can only be analyzed descriptively for various reasons, particularly in prognostic prediction. We posit that the systematic assessment of patients' PCF morphology, volume, and other parameters at a 3-dimensional level holds promising clinical application prospects.

A Rare Tick Tale: A Novel Case of the Australian Paralysis Tick Causing Multiple Cranial Neuropathies.

The Australian paralysis tick (Ixodes holocyclus) is found along the east coast of Australia. Tick bites may result in paralysis ranging from muscular weakness to ascending paralysis requiring respiratory support. Ocular complications and facial nerve involvement are rare. We present a rare occurrence of tick-bite-associated visual loss, proptosis, and multiple cranial neuropathies not previously reported in the literature. The tick was removed, and the patient's symptoms improved following treatment with steroids and oral doxycycline. The vision and sensory changes are not explained by the Ixodes toxin; thus, we hypothesize this is related to orbital apex inflammation.

Pseudomeningocele Following Posterior Cranial Fossa Surgery Significantly Increases the Risk of Intracranial Infection: A 10-Year Retrospective Analysis.

Background: Posterior fossa craniotomy is commonly performed for various pathologies. However, intra-cranial infection following craniotomy causes morbidity. Pseudomeningocele is one of the main complications following posterior fossa operation. This study aimed to test the hypothesis that the risk of intra-cranial infection is increased in patients who undergo posterior fossa craniotomy with pseudomeningocele compared with those without pseudomeningocele. Methods: We retrospectively analyzed the data of patients undergoing posterior fossa craniotomy for the management of neurological pathologies at our institute from 2011 to 2020. A total of 308 craniotomies were included, and the primary outcome of interest was the occurrence of intra-cranial infection. Standard statistical methods were used to explore associations between several parameters, including pseudomeningocele, intra-cranial infection, and wound leak. Results: Of the 308 craniotomies, 41 (13.3%) developed intra-cranial infection and 59 (19.2%) involved pseudomeningocele. Of cases involving pseudomeningocele, 27 (45.8%) developed an intra-cranial infection compared with only 14 of 249 without pseudomeningocele (5.6%; p < 0.001). In the multi-variable analysis, pseudomeningocele was associated with intra-cranial infection (odds ratio [OR] 8.56; 95% confidence interval [CI] 3.145-23.299; p < 0.001) and wound leak (OR 91.339; 95% CI 10.437-799.364; p < 0.001). Conclusion: The findings indicate that patients undergoing posterior fossa craniotomy are at a greater risk of intra-cranial infection if there is pseudomeningocele after the operation.

High risk and low prevalence diseases: Cavernous sinus thrombosis.

INTRODUCTION: Cavernous sinus thrombosis (CST) is a serious condition that carries with it a high rate of morbidity and mortality. OBJECTIVE: This review highlights the pearls and pitfalls of CST, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence. DISCUSSION: CST is a potentially deadly thrombophlebitic disease involving the cavernous sinuses. The most common underlying etiology is sinusitis or other facial infection several days prior to development of CST, though other causes include maxillofacial trauma or surgery, thrombophilia, dehydration, or medications. Staphylococcus aureus, streptococcal species, oral anaerobic species, and gram-negative bacilli are the most frequent bacterial etiologies. The most prevalent presenting signs and symptoms are fever, headache, and ocular manifestations (chemosis, periorbital edema, ptosis, ophthalmoplegia, vision changes). Cranial nerve (CN) VI is the most commonly affected CN, resulting in lateral rectus palsy. Other CNs that may be affected include III, IV, and V. The disease may also affect the pulmonary and central nervous systems. Laboratory testing typically reveals elevated inflammatory markers, and blood cultures are positive in up to 70% of cases. Computed tomography of the head and orbits with intravenous contrast delayed phase imaging is recommended in the ED setting, though magnetic resonance venography demonstrates the highest sensitivity. Management includes resuscitation, antibiotics, and anticoagulation with specialist consultation. CONCLUSION: An understanding of CST can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Exploring Phylogenetic Signal in Multivariate Phenotypes by Maximizing Blomberg's K.

Due to the hierarchical structure of the tree of life, closely related species often resemble each other more than distantly related species; a pattern termed phylogenetic signal. Numerous univariate statistics have been proposed as measures of phylogenetic signal for single phenotypic traits, but the study of phylogenetic signal for multivariate data, as is common in modern biology, remains challenging. Here we introduce a new method to explore phylogenetic signal in multivariate phenotypes. Our approach decomposes the data into linear combinations with maximal (or minimal) phylogenetic signal, as measured by Blomberg's K. The loading vectors of these phylogenetic components or K-components can be biologically interpreted, and scatterplots of the scores can be used as a low-dimensional ordination of the data that maximally (or minimally) preserves phylogenetic signal. We present algebraic and statistical properties, along with two new summary statistics, KA and KG, of phylogenetic signal in multivariate data. Simulation studies showed that KA and KG have higher statistical power than the previously suggested statistic Kmult, especially if phylogenetic signal is low or concentrated in a few trait dimensions. In two empirical applications to vertebrate cranial shape (crocodyliforms and papionins), we found statistically significant phylogenetic signal concentrated in a few trait dimensions. The finding that phylogenetic signal can be highly variable across the dimensions of multivariate phenotypes has important implications for current maximum likelihood approaches to phylogenetic signal in multivariate data.

Distribution pattern of the celiac, cranial mesenteric, and caudal mesenteric arteries to the gastrointestinal tract in the common marmoset (Callithrix jacchus).

Gastrointestinal diseases pose problems to captive common marmosets. Therefore, knowledge of the anatomy of the arterial supply to the gastrointestinal tract is an important prerequisite for implementing appropriate veterinary care. The common marmoset's intestinal tract has a well-developed cecum specialized for the fermentative digestion of tree gums. This specialized gastrointestinal tract may have a unique pattern of arterial distribution. This study aimed to elucidate the species-specific gastrointestinal tract arterial anatomy of the common marmoset. We traced the celiac, cranial mesenteric, and caudal mesenteric arteries in six male and nine female common marmosets using the latex injection method. We found that the celiac artery gave rise to the left gastric, common hepatic, splenic, and caudal pancreaticoduodenal arteries. In addition to these arteries, the celiac artery gave origin to the middle colic or jejunal arteries in seven or one cases, respectively. The branches of the cranial mesenteric artery consisted of 3-6 arteries, including the middle colic, caudal pancreaticoduodenal, jejunal, right colic, ileocolic, and ileal arteries, as well as a common trunk of the ventral cecal and ileal branches, and the dorsal cecal and colic branches. In four cases, the cranial mesenteric artery gave rise to the jejunal, ileocolic, and ileal arteries. In one of the 13 cases, the celiac and cranial mesenteric arteries formed a common trunk. The caudal mesenteric artery branched into the left colic, sigmoid, and cranial rectal arteries in all the cases. These findings provide an anatomical basis for gastrointestinal veterinary care of common marmosets.

Presumed Fourth Nerve Palsy in a Healthy and Asymptomatic Child with COVID-19 Infection.

COVID-19 can cause a wide range of ocular manifestations. The most common ocular manifestation is conjunctivitis. Neuro-ophthalmic presentations of COVID-19 are rare. Case reports suggest that COVID-19 infection can cause cranial nerve palsy, including nerves that regulate ocular movements. The present studypresented a case of fourth nerve palsy in a healthy and asymptomatic COVID-19-infected child. A healthy 10-year-old boy was referred to our eye clinic with a complaint of recent abnormal head posture and squint. His past medical history was unremarkable, and he had not received any medication or vaccinations within the last few weeks. No history of ocular or head trauma was observed. The patient was afebrile and had no respiratory symptoms. A comprehensive ocular examination was performed. All examinations, including slit-lamp, pupils, eyelids, and optic nerve heads, were normal. In ocular motor evaluations, left eye hyperdeviation was observed. Because of the history of COVID-19 in the mother of the child, he was referred to an infectious disease specialist and was tested for SARS-COV-2 with a nasopharyngeal swab specimen. The test was positive and SARS-COV-2 was detected. In addition, the patient was referred to a pediatric neurology department. Brain and orbital MRI was performed, and it was unremarkable. The post-viral fourth nerve palsy is uncommon, and post-COVID-19 has not been reported before. Clinicians should consider this infection in any recent strabismus in pediatrics. The children rarely complain of diplopia, and a recent abnormal head posture may be a sign of acquired strabismus.