Augmented Reality-Guided External Ventricular Drain Placement: A Case Report.

The placement of an external ventricular drain (EVD) is a critical neurosurgical procedure used to relieve intracranial pressure in patients with conditions such as hydrocephalus, traumatic brain injury, and intracranial hemorrhage. Traditional methods rely heavily on anatomical landmarks and the surgeon's experience, which can lead to variability in outcomes and increased risk of complications. Neuronavigation, while available, is infrequently used due to the size, cost, and set-up times associated with these devices. This report explores the use of a headset-based augmented reality (AR) system for guidance during the EVD placement procedure. We describe an AR system that overlays a 3D model of the patient's cranial anatomy, derived from preoperative imaging, onto the patient's head. This system is a head-mounted display and utilizes a rapid fiducial-less registration to provide the surgeon with visualization of 3D anatomy, and targeted trajectories. The system was used with a 32-year-old patient undergoing EVD placement prior to a cranioplasty. Due to the atypical cranial anatomy and due to prior procedures and midline shift, this relatively high-risk catheter placement was an ideal circumstance for the use of AR guidance during the EVD placement. This report described an early use of AR for EVD placement and represents a substantial advancement in neurosurgical practice, offering enhanced precision, efficiency, and safety. Further large-scale studies are warranted to validate these findings and explore the broader applicability of AR in other neurosurgical procedures.

Enteric tuft cells coordinate timely expulsion of the tapeworm Hymenolepis diminuta from the murine host by coordinating local but not systemic immunity.

Recognizing that enteric tuft cells can signal the presence of nematode parasites, we investigated whether tuft cells are required for the expulsion of the cestode, Hymenolepis diminuta, from the non-permissive mouse host, and in concomitant anti-helminthic responses. BALB/c and C57BL/6 mice infected with H. diminuta expelled the worms by 11 days post-infection (dpi) and displayed DCLK1+ (doublecortin-like kinase 1) tuft cell hyperplasia in the small intestine (not the colon) at 11 dpi. This tuft cell hyperplasia was dependent on IL-4Rα signalling and adaptive immunity, but not the microbiota. Expulsion of H. diminuta was slowed until at least 14 dpi, but not negated, in tuft cell-deficient Pou2f3-/- mice and was accompanied by delayed goblet cell hyperplasia and slowed small bowel transit. Worm antigen and mitogen evoked production of IL-4 and IL-10 by splenocytes from wild-type and Pou2f3-/- mice was not appreciably different, suggesting similar systemic immune reactivity to infection with H. diminuta. Wild-type and Pou2f3-/- mice infected with H. diminuta displayed partial protection against subsequent infection with the nematode Heligmosomoides bakeri. We speculate that, with respect to H. diminuta, enteric tuft cells are important for local immune events driving the rapidity of H. diminuta expulsion but are not critical in initiating or sustaining systemic Th2 responses that provide concomitant immunity against secondary infection with H. bakeri.

Most influential women neurosurgeons on Twitter.

Background: Social media platforms can increase gender diversity and foster community within the neurosurgical field. Women have been historically underrepresented in neurosurgery. The purpose of this study is to compile a list of women neurosurgeons on Twitter according to their social media influence and identify whether social media influence correlates with academic productivity. Methods: Women neurosurgeons (post-residency) in the United States who have Twitter accounts were obtained via the Women in Neurosurgery Twitter account and individuals who used the hashtag: #womeninneurosurgery (n= 50). Social media influence (followers, original posts, likes, retweets) was extracted through Popsters social media analytics platform for each of the accounts from January 1st, 2023 to June 30th, 2023. The efficiency metric standardized retweets for follower count, as well as number of posts. Academic H-index scores were ascertained via SCOPUS. 3 lists were created based off the efficiency metric, follower count, and average likes per post. Results: The relationship between the efficiency metric (average retweets per post per follower) and H-index was not significant at level of p < 0.05, whereas the relationships between follower count and H-index, and average likes per posts and H-index were significant at p < 0.05. Conclusion: The significant positive association found between H-index and average likes, as well as H-index and follower count demonstrates that social media influence and academic productivity/influence may go hand in hand. The lists of women neurosurgeons may serve as a guide for individuals interested in following women neurosurgeons on Twitter. Additionally, this would aid in fostering a community supportive of women neurosurgeons. Further, this may also inform individuals who would like to grow their presence on social media on how to build their following.

Angulation of the dural venous sinuses of the posterior cranial fossa: Anatomical study with clinical and surgical applications.

Cerebral vein and dural venous sinus thromboses (CVST) account for 0.5%-1% of all strokes. Some structural factors associated with a potentially higher risk for developing CVST have been described. However, angulation of the dural venous sinuses (DVS) has yet to be studied as a structural factor. The current study was performed because this variable could be related to alterations in venous flow, thus predisposing to a greater risk of CVST development. Additionally, such information could help shed light on venous sinus stenosis (VSS) at or near the transverse-sigmoid junction. The angulations formed in the different segments of the grooves of the transverse (TS), sigmoid (SS), and superior sagittal sinuses (SSS) were measured in 52 skulls (104 sides). The overall angulation of the TS groove was measured using two reference points. Other variables were examined, such as the communication pattern at the sinuses' confluence and the sinus grooves' lengths and widths. The patterns of communication between sides were compared statistically. The most typical communication pattern at the sinuses' confluence was a right-dominant TS groove (82.98%). The mean angulations of the entire left TS groove at two different points (A and B) were 46° and 43°. Those of the right TS groove were 44° and 45°. The median angulations of the left and right SSS-transverse sinus junction grooves were 127° and 124°. The mean angulations of the left and right TS-SSJsv grooves were 111° (range 82°-152°) and 103° (range 79°-130°). Differentiating normal and abnormal angulations of the DVSs of the posterior cranial fossa can help to explain why some patients are more susceptible to pathologies affecting the DVSs, such as CVST and VSS. Future application of these findings to patients with such pathologies is now necessary to extrapolate our results.

Training Cerebrovascular and Neuroendovascular Surgery Residents: A Systematic Literature Review and Recommendations.

Background: The rapid evolution of neuroendovascular intervention has resulted in the inclusion of endovascular techniques as a core competency in neurosurgical residency training. Methods: We conducted a literature review of studies involving the training of neurosurgical residents in cerebrovascular and endovascular neurosurgery. We reviewed the evolution of cerebrovascular neurosurgery and the effects of these changes on residency, and we propose interventions to supplement contemporary training. Results: A total of 48 studies were included for full review. Studies evaluated trainee education and competency (29.2%, 14/48), neuroendovascular training models (20.8%, 10/48), and open cerebrovascular training models (52.1%, 25/48), with some overlap. We used a qualitative analysis of reviewed reports to generate a series of suggested training supplements to optimize cerebrovascular education. Conclusion: Cerebrovascular neurosurgery is at a crossroads where trainees must develop disparate skill sets with inverse trends in volume. Continued longitudinal exposure to both endovascular and open cerebrovascular surgical fields should be mandated in general resident education, and blended learning tactics using adjunct simulation systems and models should be incorporated with didactics to both optimize learning and alleviate restraints placed by decreased volume and autonomy.

Assessing the clinical reasoning of ChatGPT for mechanical thrombectomy in patients with stroke.

BACKGROUND: Artificial intelligence (AI) has become a promising tool in medicine. ChatGPT, a large language model AI Chatbot, shows promise in supporting clinical practice. We assess the potential of ChatGPT as a clinical reasoning tool for mechanical thrombectomy in patients with stroke. METHODS: An internal validation of the abilities of ChatGPT was first performed using artificially created patient scenarios before assessment of real patient scenarios from the medical center's stroke database. All patients with large vessel occlusions who underwent mechanical thrombectomy at Tulane Medical Center between January 1, 2022 and December 31, 2022 were included in the study. The performance of ChatGPT in evaluating which patients should undergo mechanical thrombectomy was compared with the decisions made by board-certified stroke neurologists and neurointerventionalists. The interpretation skills, clinical reasoning, and accuracy of ChatGPT were analyzed. RESULTS: 102 patients with large vessel occlusions underwent mechanical thrombectomy. ChatGPT agreed with the physician's decision whether or not to pursue thrombectomy in 54.3% of the cases. ChatGPT had mistakes in 8.8% of the cases, consisting of mathematics, logic, and misinterpretation errors. In the internal validation phase, ChatGPT was able to provide nuanced clinical reasoning and was able to perform multi-step thinking, although with an increased rate of making mistakes. CONCLUSION: ChatGPT shows promise in clinical reasoning, including the ability to factor a patient's underlying comorbidities when considering mechanical thrombectomy. However, ChatGPT is prone to errors as well and should not be relied on as a sole decision-making tool in its present form, but it has potential to assist clinicians with more efficient work flow.

Iatrogenic Cerebrospinal Fluid Breast Augmentation: Rare Complication of Ventriculoperitoneal Shunts and Management Strategies.

BACKGROUND: Ventriculoperitoneal shunt is one of the most common neurosurgical procedures in the treatment of hydrocephalus. There are reports of migration of the distal catheter to the breast pocket where cerebrospinal fluid then collects and can develop into a pseudocyst. There exist case reports in the literature of patients with prior breast augmentation who present with distal catheter migration from the peritoneal space into the breast tissue. We present a case series of 3 patients with preexisting breast augmentation who returned with unilateral breast enlargement after ventriculoperitoneal shunt. In all 3 patients, the distal catheter migrated out of the peritoneal space and was found to be coiled around the breast prosthesis. Additionally, we offer recommendations for managing these complications and a review of the literature. METHODS: We performed a systematic review without meta-analysis of studies involving management of shunt migration in the setting of preexisting breast implants. We present a case series of 3 patients whom we treated with breast cerebrospinal pseudocyst after migration of the distal catheter into the breast tissue. RESULTS: A total of 17 studies, dating from 2002 to 2022, met our inclusion and exclusion criteria and were selected for full review. Catheter migration occurred between 2 weeks and 9 months of initial shunt placement. All patients presented with unilateral breast enlargement and cerebrospinal fluid pseudocyst formation. All patients underwent revision shunt surgery. Surgical treatment strategies used included reimplantation of the distal catheter into the pleural space or ipsilateral or contralateral peritoneal space or complete removal of the entire shunt system. CONCLUSIONS: Breast-related ventriculoperitoneal shunt complication is a rare entity that is increasingly seen as more patients receive breast augmentation. Breast-related shunt complications most commonly present with cerebrospinal fluid pseudocyst formation in the breast. It is important for neurosurgeons to be aware of an underlying breast implant before placing a ventriculoperitoneal shunt. For patients who have migration of the distal catheter into the breast, a protocol for managing these situations should be followed to ensure no shunt infection and avoidance of future catheter migration complications with subsequent shunt revisions.

Butyrate reduces adherent-invasive E. coli-evoked disruption of epithelial mitochondrial morphology and barrier function: involvement of free fatty acid receptor 3.

Gut bacteria provide benefits to the host and have been implicated in inflammatory bowel disease (IBD), where adherent-invasive E. coli (AIEC) pathobionts (e.g., strain LF82) are associated with Crohn's disease. E. coli-LF82 causes fragmentation of the epithelial mitochondrial network, leading to increased epithelial permeability. We hypothesized that butyrate would limit the epithelial mitochondrial disruption caused by E. coli-LF82. Human colonic organoids and the T84 epithelial cell line infected with E. coli-LF82 (MOI = 100, 4 h) showed a significant increase in mitochondrial network fission that was reduced by butyrate (10 mM) co-treatment. Butyrate reduced the loss of mitochondrial membrane potential caused by E. coli-LF82 and increased expression of PGC-1α mRNA, the master regulator of mitochondrial biogenesis. Metabolomics revealed that butyrate significantly altered E. coli-LF82 central carbon metabolism leading to diminished glucose uptake and increased succinate secretion. Correlating with preservation of mitochondrial network form/function, butyrate reduced E. coli-LF82 transcytosis across T84-cell monolayers. The use of the G-protein inhibitor, pertussis toxin, implicated GPCR signaling as critical to the effect of butyrate, and the free fatty acid receptor three (FFAR3, GPR41) agonist, AR420626, reproduced butyrate's effect in terms of ameliorating the loss of barrier function and reducing the mitochondrial fragmentation observed in E. coli-LF82 infected T84-cells and organoids. These data indicate that butyrate helps maintain epithelial mitochondrial form/function when challenged by E. coli-LF82 and that this occurs, at least in part, via FFAR3. Thus, loss of butyrate-producing bacteria in IBD in the context of pathobionts would contribute to loss of epithelial mitochondrial and barrier functions that could evoke disease and/or exaggerate a low-grade inflammation.

Assessment of ChatGPT's performance on neurology written board examination questions.

Background and objectives: ChatGPT has shown promise in healthcare. To assess the utility of this novel tool in healthcare education, we evaluated ChatGPT's performance in answering neurology board exam questions. Methods: Neurology board-style examination questions were accessed from BoardVitals, a commercial neurology question bank. ChatGPT was provided a full question prompt and multiple answer choices. First attempts and additional attempts up to three tries were given to ChatGPT to select the correct answer. A total of 560 questions (14 blocks of 40 questions) were used, although any image-based questions were disregarded due to ChatGPT's inability to process visual input. The artificial intelligence (AI) answers were then compared with human user data provided by the question bank to gauge its performance. Results: Out of 509 eligible questions over 14 question blocks, ChatGPT correctly answered 335 questions (65.8%) on the first attempt/iteration and 383 (75.3%) over three attempts/iterations, scoring at approximately the 26th and 50th percentiles, respectively. The highest performing subjects were pain (100%), epilepsy & seizures (85%) and genetic (82%) while the lowest performing subjects were imaging/diagnostic studies (27%), critical care (41%) and cranial nerves (48%). Discussion: This study found that ChatGPT performed similarly to its human counterparts. The accuracy of the AI increased with multiple attempts and performance fell within the expected range of neurology resident learners. This study demonstrates ChatGPT's potential in processing specialised medical information. Future studies would better define the scope to which AI would be able to integrate into medical decision making.

Chat GPT as a Neuro-Score Calculator: Analysis of a Large Language Model's Performance on Various Neurological Exam Grading Scales.

BACKGROUND: ChatGPT is a large language model artificial intelligence chatbot that has been applied to different aspects of the medical field. Our study aims to assess the quality of chatGPT to evaluate patients based on their exams for different scores including Glasgow Coma Scale (GCS), intracranial hemorrhage score (ICH), and Hunt & Hess (H&H) classification. METHODS: We created batches of patient test cases with detailed neurological exams, totaling 20 cases and created variants of increasing complex phrasing of the test cases. Using ChatGPT, we assessed repeatability and quantified the errors, including the average error rate (AER) and magnitude of errors (AME). We repeated this process for the H&H and the ICH score using base cases. Specific prompts were created for each calculator. RESULTS: The GCS calculator on 10 base test cases had an AER/AME of 10%/0.150. The accuracy of ChatGPT decreased with increasing complexity; for example, in a variation where crucial information was missing, the AER was 45% for 20 cases. For H&H, AER/AME was 13%/0.13 and for ICH, AER/AME was 27.5%/0.325. Using a simple prompt resulted in a significantly higher error rate of 70%. CONCLUSIONS: ChatGPT demonstrates ability in this proof-of-concept experiment in evaluating neuroexams using established assessment scales including GCS, ICH, and H&H. However, it has limitations in accuracy and may "hallucinate" with complex or vague descriptions. Nonetheless, ChatGPT, has promising potential in medicine.

Voices from Service Providers Who Supported Young Caregivers throughout the COVID-19 Pandemic in the Canadian Context.

This empirical research is part of a larger project beginning in 2020 and ongoing until 2023, exploring the impact of the COVID-19 pandemic on young caregivers aged 5-25 years and their families in Canada. This qualitative research utilizes the social determinants of health as a conceptual framework and a collective case study design to emphasize the voices and experiences of service providers (professionals offering services to young caregiver clients) during the COVID-19 pandemic, and exploring their perspectives on the impact of the pandemic on young caregivers and their families. The central research question guiding this study was "How do service providers (professionals) working with young caregiver clients in Canada describe the impacts of the pandemic on themselves, their professional praxis, and on their young caregiver clients?" The aim of this study was to develop a deeper understanding of the impact of the pandemic on young caregivers in Canada, from the perspectives of service providers, as well as to understand the experiences of service providers in their own voices. Data were collected from service providers working within three (3) different organizations offering programs and services to young caregiver clients in Ontario, Canada. In total, six (6) individual interviews were conducted with service providers who were directors/program managers, and four (4) group interviews were conducted with thirteen (13) service providers who were frontline staff members who worked directly with young caregivers and their families. In total, nineteen (n = 19) unique service providers participated in this study. Our findings point to two primary overarching themes, namely (1) service providers' responses to the pandemic and (2) observations by service providers about the impacts of the pandemic on young caregivers, and a secondary theme, (3) positive outcomes from the COVID-19 pandemic on young caregivers, that emerged through the analysis. The pandemic led to increased demands for services by young caregiver clients. Service providers were required to adapt their service delivery methods in order to comply with public health guidelines. They shared how their work impacted their mental health as they struggled to maintain personal and professional boundaries while working from home during the pandemic. Importantly, service providers identified similar, simultaneous, and co-occurring impacts of the pandemic between their young caregiver clients, including isolation, difficulties in navigating online spaces, and challenges in navigating boundaries while working from home with family members.

Dural Closure Techniques and Cerebrospinal Fluid Leak Incidence After Resection of Primary Intradural Spinal Tumors: A Systematic Review.

STUDY DESIGN: This is a systematic review of primary intradural spinal tumors (PIDSTs) and the frequency of postoperative cerebrospinal fluid (CSF) leaks. OBJECTIVE: This study aimed to compare CSF leak rates among techniques for dural watertight closure (WTC) after the resection of PIDSTs. SUMMARY OF BACKGROUND DATA: Resection of PIDSTs may result in persistent CSF leak. This complication is associated with infection, wound dehiscence, increased length of stay, and morbidity. Dural closure techniques have been developed to decrease the CSF leak rate. METHODS: A PubMed search was performed in 2022 with these inclusion criteria: written in English, describe PIDST patients, specify the method of dural closure, report rates of CSF leak, and be published between 2015 and 2020. Articles were excluded if they had <5 patients. We used standardized toolkits to assess the risk of bias. We assessed patient baseline characteristics, tumor pathology, CSF leak rate, and dural closure techniques; analysis of variance and a 1-way Fisher exact test were used. RESULTS: A total of 4 studies (201 patients) satisfied the inclusion criteria. One study utilized artificial dura (AD) and fibrin glue to perform WTC and CSF diversion, with lumbar drainage as needed. The rate of CSF leak was different among the 4 studies (P=0.017). The study using AD with dural closure adjunct (DCA) for WTC was associated with higher CSF leak rates than those using native dura (ND) with DCA. There was no difference in CSF leak rate between ND-WTC and AD-DCA, or with any of the ND-DCA studies. CONCLUSIONS: After resection of PIDSTs, the use of autologous fat grafts with ND resulted in lower rates of CSF leak, while use of fibrin glue and AD resulted in the highest rates. These characteristics suggest that a component of hydrophobic scaffolding may be required for WTC. A limitation included articles with low levels of evidence. Continued investigation to understand mechanisms for WTC is warranted. LEVEL OF EVIDENCE: Level 3.

The Impact of Public Health Restrictions on Young Caregivers and How They Navigated a Pandemic: Baseline Interviews from a Longitudinal Study Conducted in Ontario, Canada.

This qualitative research study is a part of a larger research project exploring the experiences of young caregivers aged 5-26 years and their families navigating the COVID-19 pandemic between 2020 to 2023. Data were collected from 14 young caregivers who participated in baseline interviews. The central research question guiding this study: What was, is, and will be the impact of changing public health restrictions on young caregivers and their families during the pandemic and pandemic recovery? Seven themes emerged through analysis: (1) Navigating Care During the Height of Public Health Restrictions, (2) Neighbourhood and Built Environment During the Pandemic, (3) Perceptions Towards COVID-19 and Public Health Restrictions/Efforts, (4) The Impact of Public Health Restrictions on Relationships, (5) Mental Health Challenges of Being a Young Caregiver During a Pandemic, (6) Navigating Formal Services and Supports, and (7) Recommendations from Young Caregivers. The findings from this empirical research suggest that young caregivers found it easier to navigate their caregiving responsibilities when public health restrictions and work-from-home mandates were initially implemented; however, this later changed due to challenges in finding respite from caregiving, maintaining social connections with friends, creating personal space at home, and finding adequate replacements for programs once offered in person.

Early tracheostomy in patients undergoing mechanical thrombectomy for acute ischemic stroke.

PURPOSE: Respiratory failure following mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is a known complication, and requirement of tracheostomy is associated with worse outcomes. Our objective is to evaluate characteristics associated with tracheostomy timing in AIS patients treated with MT. METHODS: The National Inpatient Sample was queried for adult patients treated with MT for AIS from 2016 to 2019. Baseline demographic characteristics, comorbidities, and inpatient outcomes were analyzed for associations in patients who received tracheostomy. Timing of early tracheostomy (ETR) was defined as placement before day 8 of hospital stay. RESULTS: Of 3505 AIS-MT patients who received tracheostomy, 915 (26.1%) underwent ETR. Patients who underwent ETR had shorter length of stay (LOS) (25.39 days vs 32.43 days, p < 0.001) and lower total hospital charges ($483,472.07 vs $612,362.86, p < 0.001). ETR did not confer a mortality benefit but was associated with less acute kidney injury (OR, 0.697; p = 0.013), pneumonia (OR, 0.449; p < 0.001), and sepsis (OR, 0.536; p = 0.002). CONCLUSION: An expected increase in complications and healthcare resource utilization is seen in AIS-MT patients receiving tracheostomy, likely reflecting the severity of patients' post-stroke neurologic injury. Among these high-risk patients, ETR was predictive of shorter LOS and fewer complications.

Minimally Invasive Hematoma Evacuation Using the MindsEye Expandable Tubular Retractor: A Technical Note.

BACKGROUND: Recent advances in intraoperative neuronavigation and cranial access devices have facilitated an increasing interest in the use of minimally invasive techniques (minimally invasive surgery) to safely treat subcortical lesions via a parafascicular approach. Newly developed expandable retractors, such as the MindsEye system further optimize such approaches. In this technical report, we describe the nuances in minimally invasive surgery parenchymal hematoma evacuation using the MindsEye device. METHODS: After placement of the device, the inner stylet and inner obturator are removed, and the expandable sheath is left in place and secured into place with a Greenberg refractor. The sheath easily dilates to the surgeonss preference with a dial, and the walls of the sheath are composed of a thin, clear, membrane to allow easy visualization of the lesion. We additionally retrospectively reviewed clinical characteristics and outcomes across three patients treated at our facility with spontaneous multicompartment intracranial hematoma using the MindsEye system. RESULTS: We provide a video case demonstrating the use of the MindsEye retractor in a transfrontal parenchymal hematoma evacuation. Successful evacuation with achieved in less than 90 minutes with near total clot removal and resolution of mass effect for all reviewed cases with no patients experiencing procedure-related postoperative decline. CONCLUSIONS: Minimally invasive catheter-based and parafascicular approaches using tubular retractors are increasingly recognized as a viable option in the treatment of subcortical lesions. The MindsEye is the first expandable brain access port designed for removal of deep intracranial lesions. We believe it represents a recent addition in the armament of cranial surgeons.

Combining chemotherapy with CAR-T cell therapy in treating solid tumors.

Chemotherapy has long been a standard treatment for a wide range of malignancies, where patients typically undergo multiple rounds of chemotherapy regimens to control tumor growth. In the clinic, the chemotherapy drugs cyclophosphamide and fludarabine are commonly used prior to Chimeric Antigen Receptor T (CAR-T) cell therapy to lymphodeplete and improve CAR-T cell engraftment. In this review, we discuss the use of chemotherapy in combination with CAR-T cell therapy. We also show that chemotherapy can deplete immunosuppressive cells, promote a pro-inflammatory tumor microenvironment, disrupt tumor stroma, and improve CAR-T cell recruitment to the tumor. Although the combination of chemotherapy plus CAR-T cell therapy is promising, certain aspects of chemotherapy also pose a challenge. In addition, the combined therapeutic effect may be heavily dependent on the dose and the treatment schedule. Thus, we also discussed the obstacles to effective clinical outcomes of the combination therapy.

The Sphenoparietal Sinus Revisited: Anatomical and Histological Study With Application to Interventional Procedures and Skull Base Surgery.

Background The sphenoparietal sinus (SPS) is implicated in various clinical pathologies, specifically arteriovenous fistulas and venous sinus thrombosis. This study is aimed to better understand this venous structure of the skull base via histological examination. Methods Ten embalmed and latex-injected adult body donors' heads (20 sides) underwent microdissection of the SPS using a surgical microscope. The entire dura on the underside of the lesser wing of the sphenoid bone encompassing the region known as the groove for the SPS was harvested from each body donor and submitted for histological analysis (H&E, Periodic acid-Schiff [PAS], Masson's Trichrome). Five left and five right transverse sinuses were harvested and analyzed histologically as controls. Results A definitive SPS was identified in 14/20 (70%) of the latex-injected body donors. When present, the sinuses were classified as small, medium, or large. Tributaries included the middle meningeal veins, superficial Sylvian vein, and anterior temporal veins. All sinuses drained medially into the cavernous sinus. For the body donors analyzed histologically, 17 (85%) were consistent with a dural venous sinus and not a vein and were observed to have a rich nerve and arterial supply within their walls. The histological findings of the SPS were similar to those seen for the transverse sinus. The combined prevalence for the SPS in gross and histological body donors was 78%. Conclusions Our findings support the presence of SPS in the majority of body donors. To our knowledge, this is the first histological study of the SPS.

MicroEXPERT: Microbiome profiling platform with cross-study metagenome-wide association analysis functionality.

The framework of the MicroEXPERT platform. Our Platform was composed of five modules. Data management module: Users upload raw data and metadata to the system using a guided workflow. Data processing module: Uploaded data is processed to generate taxonomical distribution and functional composition results. Metagenome-wide association studies module (MWAS): Various methods, including biomarker analysis, PCA, co-occurrence networks, and sample classification, are employed using metadata. Data search module: Users can query nucleotide sequences to retrieve information in the MicroEXPERT database. Data visualization module: Visualization tools are used to illustrate the metagenome analysis results.

Characteristics and Management of Dilated Mastoid Emissary Veins: A Case Report and Literature Review.

INTRODUCTION: The mastoid emissary vein (MEV) describes a transosseous connection between the sigmoid dural venous sinus and the suboccipital venous plexus. In cases of outflow stenosis or malformation, the MEV may become dilated and a source of pulsatile tinnitus (PT) amenable to treatment. We describe a case of PT secondary to MEV treated successfully via endovascular coil embolization and conduct a systematic review of the literature. METHODS: We performed a systematic review without meta-analysis of studies involving management of dilated MEV on January 14, 2022, and describe a case of PT secondary to an enlarged MEV treated via coil embolization. RESULTS: A total of 13 studies were selected for full review. Reports identified MEV presenting as PT in 60% (12 of 20) of cases, intraoperative hemorrhage in mastoid surgery in 15% (3 of 20), a compressive scalp mass in 10% (2 of 20), and thrombophlebitis, facial swelling, or an incidental finding in 5% (1 of 20) each. Forty-five percent (9 of 20) underwent treatment, with all experiencing symptom resolution or improvement. Surgery included transvenous coil embolization in 33.3% (3 of 9), flap reconstruction in 22.2% (2 of 9), and surgical packing, ligation, and thrombectomy in 11.1% (1 of 9) each. Dilated MEV was reported concurrently with impeded drainage pathways in 35% (7 of 20) of reports. CONCLUSIONS: Dilated MEV has been reported as an etiology of pulsatile tinnitus and appears amenable to treatment via open and endovascular means. Endovascular coil embolization appears to offer effective symptom resolution, however, available literature exists only in case reports and small series. Further investigation is highly warranted.

Intracranial Aneurysms in the Context of Variant Cerebrovascular Anatomy: A Review of the Literature.

BACKGROUND: The cerebrovascular anatomy varies, with many associated variants and persistent channels. Many such vessels have been reported to carry an increased risk of intracranial aneurysm (IA) formation. We conducted a systematic literature review of IAs associated with variant anatomy. METHODS: We performed a systematic review without a meta-analysis in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines for studies involving IA formation in patients with variant anatomy. Studies were excluded if 1) the IAs were associated with malformations; 2) the variant anatomy discussed was in the form of segment hypoplasia or aplasia; 3) the anatomical variants were discussed secondary to the intervention; 4) insufficient information had been included; or 5) they were literature reviews. RESULTS: A total of 64 studies had met the inclusion and exclusion criteria for the final review. IA rupture was present in 91 of 131 cases (69.5%). Of the 131 IAs, 45 (34.3%) had been associated with an anomalous vessel origin or course, 43 with segmental fenestration (32.8%), 26 with a primitive persistent anastomosis (19.8%), and 17 with multiple or accessory vessels (12.9%). A total of 122 IAs (93.1%) had been treated with endovascular (64 of 122; 52.5%), microsurgical (57 of 122; 43.5%), or combined (1 of 122; 0.8%) methods. CONCLUSIONS: Variant, anomalous, and persistent primitive anatomy have often been reported in association with IA formation. These lesions present with a high proportion of rupture and warrant a low threshold for treatment. Preservation of perfusion is critical because such vessels developmentally exist to maintain flow.