Background: Surgical access to the clival region is challenging, but advanced endoscopic endonasal approaches (EEA) provide a minimally invasive corridor. This study aimed to review the clinical outcomes of patients who underwent EEA for skull base lesions involving the clivus and to analyze prognostic factors. Methods: A retrospective review was conducted of patients who underwent EEA for resection of clival lesions between October 2001 and October 2023. Data on demographics, approach type, reconstruction technique, tumor pathology and outcomes were collected. Results: Forty-six patients underwent transclival EEA. The majority had ASA scores II and III (71.7%), with clival chordomas being the most common pathology (37%). Cranial nerve impairment was present in 65% of patients, and 80% showed improvement post-surgery. The mean procedure duration was 308 minutes, with a mean blood loss of 424 mL. A lumbar drain was used in 10.9%, and 76.1% received a pedicled nasoseptal flap for reconstruction. Complete tumor resection was achieved in 74% of malignant cases. Postoperative CSF leaks occurred in 4.3%, and the mean length of stay was 12.2 days. Higher readmission rates were associated with ASA IV classification (p=0.006). Conclusions: EEA to the clival region is safe and effective, with low perioperative complications and high rates of postoperative improvement.

Background: We previously developed a DNA methylation-based risk predictor for meningioma, which has been used locally in a prospective fashion. As a follow-up, we validate this model using a large prospective cohort and introduce a streamlined next-generation model compatible with newer methylation arrays. Methods: The performance of our next-generation predictor was compared with our original model and standard-of-care 2021 WHO grade using time-dependent receiver operating characteristic curves. A nomogram was generated by incorporating our methylation predictor with WHO grade and extent of resection. Results: A total of 1347 meningioma cases were utilized in the study, including 469 prospective cases from 3 institutions and a retrospective cohort of 100 WHO grade 2 cases for model validation. Both the original and next-generation models significantly outperformed 2021 WHO grade in predicting postoperative recurrence. Dichotomizing into grade-specific risk subgroups was predictive of outcome within both WHO grades 1 and 2 tumours (log-rank p<0.05). Multivariable Cox regression demonstrated benefit of adjuvant radiotherapy in high-risk cases specifically, reinforcing its informative role in clinical decision making. Conclusions: This next-generation DNA methylation-based meningioma outcome predictor significantly outperforms 2021 WHO grading in predicting time to recurrence. This will help improve prognostication and inform patient selection for RT.

Background: Neurofibromatosis 1 (NF1) is a multisystem neurocutaneous disorder. Treatment involves multiple specialists. There are currently no multidisciplinary clinics for adults with NF1 in BC, which impacts communication between subspecialties. We sought perspectives of patients and providers to identify the impact of and solutions to gaps in care. Methods: Focus groups with patients (2 groups; 9 patients) and physicians (10) who see people with NF1 were conducted. Thematic content analysis was applied to the data to derive major themes. Concurrently, quarterly NF multidisciplinary rounds were initiated to enhance coordination of care. Results: Major themes emerged around the need for increased coordination and communication amongst providers. Specifically, physicians identified working in “siloed care structures”, and patients and providers identified lack of awareness of expertise and barriers to accessing care. Conclusions: Focus groups enable inclusion of patient and provider perspectives in developing solutions to gaps in care. The importance of supporting interdisciplinary communication in caring for NF1 patients was confirmed in focus groups. To date, we have held multidisciplinary NF rounds, with 12 cases discussed. Disciplines represented include neurology, pediatrics, radiology, neuro-ophthalmology, neuro-otology, pathology, orthopedic plastic and neurosurgery, medical and radiation oncology, and the hereditary cancer program. Telehealth format enables participation from distributed centres across BC.

Background: Generalized myasthenia gravis (gMG) is a rare, chronic, autoimmune disease characterized by muscle weakness and fatigue. This study aims to describe the natural history, disease burden and treatment patterns of gMG patients in Canada. Methods: Data was analyzed from the Adelphi MG II DSP™, a gMG patient-level cross-sectional database, collected through surveys between February-June 2024. Neurologists provided sociodemographic, symptomatology, and treatments data. Results: Fifteen neurologists provided data for 46 gMG patients. The cohort’s mean (SD) age was 58.1 (14.7) years, 52.2% male, 82.6% White/Caucasian and 89.1% were anti-AChR Ab positive. Mean time since diagnosis was 3.4 (3.1) years, 22% reported a change in employment status due to gMG. Most had public insurance (68.9%). Disease severity was mostly MGFA class II (78.2%) patients. Common symptoms included eyelid ptosis (76.1%), dysarthria (50.0%), and dyspnea (54.3%) – mean MG-ADL was 5.6 (5.1). During their disease course, 34.9% experienced ≥1 myasthenic crisis, while 25.6% reported symptom exacerbation. At time of survey, patients had used 1.8 (0.9) lines of maintenance treatment. Most prescribed treatments (alone or in combinations) were pyridostigmine (95.6%), corticosteroids (48.9%), non-steroidal immunosuppressants (42.2%), Immunoglobulins (31.1%), and biologics (22.2%). Conclusions: gMG patients continue to experience symptoms burden and crisis/exacerbations. These findings highlight an unmet need for new, safe and effective therapeutics that are publicly covered to manage gMG-related clinical manifestations.

Background: Presence of right-to-left shunt has been proposed as a mechanism of paradoxical embolism in patients with active cancer. Our study thus aims to investigate the role of shunting in stroke occurrence among cancer patients. Methods: This is a retrospective study with our population consisting of patients presenting to the Ottawa Hospital with ischemic stroke between January 01, 2020, and December 31, 2022. Presence of right-to-left shunting is identified in patients with and without cancer diagnosis within one year of ischemic stroke. The prevalence of shunt is assessed using 95% confidence intervals (CI). Results: Among654 patients, 495 (37% female, median age 53 years) were included in the study, in which 47 (9.5%) had active cancer, with 12 patients (25.5%, 95% CI 14 - 40) diagnosed with a shunt. In contrast, among 448 patients (90.5%) without active cancer, 133 patients (30%, 95% CI 25 - 34) were found to have a shunt. Conclusions: The prevalence of right-to-left shunting tends to be lower in patients with ischemic stroke and active cancer diagnosis. Our results are similar to a recent study indicating a higher rate of shunt among patients without cancer. Our finding does not support the hypothesis that cancer-associated stroke is related to right-to-left shunting.

Background: Absence epilepsy is a common epilepsy syndrome in children. This can have a negative impact on the cognitive abilities of preschool and school-age children. The objective was to study in the Guinean context, the epidemiological, clinical, electrophysiological, therapeutic and evolutionary aspects of this syndrome. Methods: The study included all children diagnosed with absence epilepsy based on evidence obtained from history, clinical, and electroencephalogram. Results: The cohort was made up of 41 girls and 28 boys with a sex ratio (F/M) equal to 1.46. The mean age was 8 ± 2 years with extremes of 2 and 14 years. The simple absences were observed in 42.02% of cases. The components : tonic was associated in 11.59%, clonic in 10.14%, atonic in 13.04%, automatisms in 15.94% and vegetative in 7.25%. EEG was typical in 75.36%. As monotherapy, sodium valproate was used in 92.75% and ethosuximide in 2.9%. The evolution was marked by a remission of seizures in 85.51%. During follow-up, the appearance of tonic-clonic convulsions was noted in 4.3%, myoclonus in 2.9%, a combination of myoclonus and tonic-clonic convulsions noted in 4.3%. Conclusions: Effective and efficient collaboration between stakeholders is essential for the best overall management of this syndrome with serious cognitive repercussions in children.

Background: Body image research in young people with physical disabilities like cerebral palsy (CP) has received very little attention. The goal of this pilot study is to ask youth with CP (of all levels of disability) directly about body image to learn their perspective. Methods: Our study includes quantitative data of quality-of-life measures, along with qualitative interview data summarized via thematic analysis. Our data is augmented with input from siblings (without CP) of our primary participants to represent a control group in the same family unit. Results: Twelve youths with CP (7 male, 5 female) participated in the study. Withe the higher score representing more positive the body image, scores averaged 17.93/25 (SD 4.73) for those with CP, 18.62/25 (SD 5.45) for those without CP. There were higher scores for males and those ≤13yo compared to 14-18yo. Interview thematic analysis uncovers themes of functional capability, the wish to reduce burden on family, pride in the CP identity, and mixed desirability of media representation. Conclusions: There is greater difference between age groups and genders than there is between those with CP and not. Interviews with participants revealed the important recurring theme of functional capacity connected to positive self-image, which may be considered justification for interventions.

Background: This study aims to review the clinical outcomes, extent of resection, complications, and prognostic factors in patients undergoing endonasal endoscopic resection (EEA) of anterior cranial base meningiomas. Methods: We conducted a retrospective review of 25 patients who underwent EEA resection of these lesions between 2001 and 2023. We assessed the extent of resection, complications, postoperative outcomes, and key technical aspects of the procedure. Results: 84% of patients were classified as ASA class III. Additionally, 64% of patients presented with visual disturbances. The mean blood loss was 472 ml. Intraoperative lumbar drains were used in 40% of cases, and dural sealants in 56%. A pedicled nasal flap was employed for reconstruction in 92% of cases. One vascular injury was documented, and 16% of patients developed a cerebrospinal fluid (CSF) leak in the postoperative period The degree of resection varied according to tumor location. Prognostic factors for achieving gross total resection, functional improvement, and key factors for reconstruction are discussed. The rate of CSF leaks decreased dramatically in the later years of the series Conclusions: Cranial base meningiomas can be successfully managed via a purely endoscopic endonasal approach, with acceptable morbidity and mortality rates.

Background: Access to neurosurgical care is vital for conditions such as traumatic brain injuries and brain tumours. However, significant disparities in healthcare access persist in Canada, disproportionately affecting rural, Indigenous, and socioeconomically disadvantaged populations. This qualitative scoping review examines barriers and facilitators to neurosurgical access, addressing gaps in the literature concerning equity-deserving groups. Methods: A systematic literature search (2000–2024) was conducted within MEDLINE, EMBASE, Cochrane Library, PsycINFO, and Scopus, along with gray literature from governmental and non-governmental organizations. From 1400 identified records, eight qualitative or mixed-methods studies met the inclusion criteria. Thematic analysis was conducted to explore socioeconomic, geographic, racial, gender-based, and cultural barriers. Results: Four major themes emerged: delays in access, alternative healthcare options, policy barriers, and communication and coordination issues. Barriers such as transportation gaps, socioeconomic inequities, and systemic discrimination were particularly pronounced for rural and Indigenous populations. Facilitators like telehealth and improved inter-hospital coordination show potential but are limited by infrastructure constraints and cultural misalignments. Conclusions: Addressing barriers to neurosurgical care requires systemic reforms, including equitable resource allocation, expanded digital infrastructure, and culturally competent care. The lack of intersectional research on overlapping barriers underscores the need for future studies to prioritize tailored interventions to ensure timely, equitable neurosurgical care across Canada.

A new species of Loimos MacCallum, 1917 is described more than half a century after the last species was described in 1972. The new species was collected from the gills of Rhizoprionodon taylori (Ogilby, 1915) off the Central Queensland coast, Australia, and is the first Loimos species and the first representative of the Loimoinae Price, 1936 known from Oceania. A detailed morphological description and 28S rDNA molecular sequences are provided for the new species. In the molecular phylogeny based on available 28S rDNA sequences for relevant Monocotylidae, the new species grouped together with the only other Loimos sequence available in GenBank, that of the nonugen Loimos sp. from China (OM060238), sister to Loimosina wilsoni Manter, 1944. The estimated genetic divergence between the new species and the nonugen Loimos sp. sequence is low, between 0.0452 and 0.0737, suggesting that the nonugen sequence may represent the new species, or a very closely related congener. Host identity was confirmed by comparing COI sequences with those of known sharks in GenBank. We also provide the first 12S and 16S molecular sequences for this shark species.

Background: Association between age, frailty, and the receipt of thrombectomy for acute ischemic stroke is not well understood. Methods: We conducted a population-based retrospective cohort study of adults hospitalized with an ischemic stroke between 2018 and 2022 in Ontario, Canada. In sex-stratified models, we studied whether frailty (based on hospital-based frailty index: mild, moderate and severe) modified the association between age and thrombectomy by using interaction terms in multivariable modified Poisson regression models. Results: Among 59,346 patients (median age 75 years, 47.0% female) with ischemic stroke 4,454 (7.5%) received thrombectomy, with no sex differences in this treatment. In both sexes, increasing age was associated with decreased use of thrombectomy (adjusted risk ratio [aRR] for every 5-year increase, female = 0.91; 0.89-0.92; male = 0.92; 0.90-0.94). Frailty was not associated with thrombectomy in females (aRR high vs. low frailty = 0.86; 0.68-1.10) or males (aRR high vs. low frailty = 1.10; 0.87-1.39). Furthermore, the interaction between age and frailty was not significant for either sex. Conclusions: Frailty was not associated with thrombectomy in either sex, and it did not modify the association between age and thrombectomy, suggesting a greater role of chronological age compared to frailty in thrombectomy decisions in ischemic stroke patients.

Background: Pathogenic variants in SYNGAP1causedevelopmental and epileptic encephalopathy (DEE) and intellectual disability. Seizures are medically refractory and there is limited evidence on the use of corpus callosotomy (CC) and vagal nerve stimulation (VNS). Methods: A retrospective study was completed examining the effectiveness of VNS and CC in children with SYNGAP1-DEE using the SynGAP Research Database and an additional child followed at our centre. Results: Fifteen patients from the SynGAP Database were included. Of those who had VNS (n=11), 7 children had an >50% reduction in seizure frequency (n=7/11, 64%), 2 had worsening (n=2/11, 18%), 1 had no change (n=1/11, 9%), and 1 had an unknown response (n=1/11, 9%). Two children had CC only, 1 had complete seizure freedom, and 1 had a >50% reduction. Two children underwent VNS and CC, 1 had a >50% reduction in seizure frequency and the other had no change. One child followed at our centre experienced a sustained >80% reduction in seizure frequency following CC (i.e., after 1.5 years). Conclusions: We provide the first in-depth description of the response to VNS and CC in children with SYNGAP1-DEE, and provide insight into the use of of palliative surgical procedures in this population.

In this article, I argue for a “multifunctional account” of political feasibility and against recent attempts by several theorists to defend accounts of political feasibility that reduce feasibility judgments to a single function. According to the view I defend, political feasibility can (and should) serve multiple useful functions in our political deliberative practices. This pluralist and context-dependent approach allows us to retain the insights provided by various monofunctional accounts, while avoiding the limitations of each.

Trematodes of the genus Paralecithodendrium parasitize bats worldwide. Among them, the identification of Paralecithodendrium longiforme and Paralecithodendrium cryptolecithum is complicated by their high morphological similarity. We studied Paralecithodendrium trematodes from the small intestine of bats inhabiting the Middle Volga region (European Russia). The aim of our study was to analyze these two Paralecithodendrium species using both morphological and molecular phylogenetic approaches. Here, we present the first complete morphological description and molecular phylogenetic analysis of Paralecithodendrium cryptolecithum from bats in Russia and confirm the validity of this species.

Background: This study explored whether Myelin Water imaging could detect myelin injury in Anti-NMDA receptor autoimmune encephalitis (NMDAr-AIE), where traditional neuroimaging is often normal. Myelin Water Fraction (MWF) quantifies myelin content by distinguishing myelin sheath water from other brain water compartments. Methods: Adult participants with confirmed NMDAr-AIE diagnoses and healthy controls (HC) underwent 3T brain MRI including MWF mapping. Participants were recruited after discharge from the hospital. Mean MWF was calculated for 4 white matter regions of interest (ROI). Patient demographics, clinical assessments, treatment, and outcomes were collected. Results: Five participants with NMDAr-AIE (4F/1M, mean age 30, SD 7) and four HC (3F/1M, mean age 36, SD 6) were included. All NMDAr-AIE participants had normal or non-specific T2 hyperintensities on initial imaging and had received immunotherapy. The mean Modified Rankin Score (MRS) on discharge was 2. MWF (mean ± SD) for normal-appearing white matter, corpus callosum, corticospinal tract, and superior longitudinal fasciculus were 0.10±0.02, 0.12±0.02, 0.15±0.03, 0.12±0.02, which were very similar to HC at 0.09±0.02, 0.11±0.01, 0.15±0.02, and 0.11±0.02, respectively. Conclusions: Myelin Water imaging showed no myelin pathology in five NMDAr-AIE patients, with MWF values comparable to HC. This suggests that myelin pathways are relatively preserved post-recovery from AIE.

Background: Anti-CD20 monoclonal antibodies are highly effective for RMS treatment. Ocrelizumab (OCR) is standard, while Rituximab (RTX) is an alternative. The impact of anti-CD20 therapies on immune markers remains understudied, though deficiencies are frequently observed and have been associated with increased risk of infection. Our objective is to characterize and compare lymphocyte, neutrophil, and immunoglobulin levels in OCR- versus RTX-treated persons with RMS. Methods: This retrospective chart review included RMS patients on OCR or RTX (2017–2023). Pre- and post-treatment levels of lymphocytes, neutrophils, and immunoglobulins (IgG, IgA, IgM) were analyzed. Kaplan-Meier curves, log-rank tests, and Cox proportional hazards models were used for survival analysis. Results: 350 patients (OCR=175, RTX=175) were included. The mean treatment length was 60.9 (SD 19.1) months for OCR and 42.7 (SD 19.5) months for RTX. RTX was associated with a significantly shorter time to IgM deficiency (29.6 vs. 40.0 months, p=0.02). Cox analysis confirmed RTX increased IgM deficiency risk (HR=1.54, 95% CI: 1.06-2.23, p=0.02). No differences were seen for lymphocytes, neutrophils, IgG, or IgA. Conclusions: RTX was associated with a shorter time to and increased risk of IgM hypogammaglobulinemia compared to OCR, highlighting the importance of long-term monitoring. Further research is needed to guide treatment decisions.

Background: Artificial intelligence (AI) holds promise to predict outcomes for patients sustaining moderate to severe traumatic brain injury (msTBI). This systematic review sought to identify studies utilizing AI-based methods to predict mortality and functional outcomes after msTBI, where prognostic uncertainty is highest. Methods: The APPRAISE-AI quantitative evidence appraisal tool was used to evaluate methodological quality of included studies by determining overall scores and domain-specific scores. We constructed a multivariable linear regression model using study sample size, country of data collection, publication year and journal impact factor to quantify associations with overall APPRAISE-AI scores. Results: We identified 38 studies comprising 591,234 patients with msTBI. Median APPRAISE-AI score was 45.5 (/100 points), corresponding to moderate study quality. There were 13 low-quality studies (34%) and only 5 high-quality studies (13%). Weakest domains were methodological conduct, robustness of results and reproducibility. Multivariable linear regression highlighted that higher journal impact factor, larger sample size, more recent publication year and use of data that were collected in a high-income country were associated with higher APPRAISE-AI overall scores. Conclusions: We identified several study weaknesses of existing AI-based prediction models for msTBI; this work highlights methodological domains that require quality improvement to ultimately ensure safety and effiicacy of clinical AI models.