Background: Receiving and managing neurosurgical consultations are central to providing quality patient care but are resource intensive processes. As part of an ongoing quality improvement initiative, we conducted a single-institution descriptive analysis of adult neurosurgical consultations. Methods: A retrospective review of prospectively collected consultation records and call schedules from a 12-month period from February 2019 to 2020 was performed. Consults were graded according to disposition (admission for surgery, non-operative admission, additional investigations recommended, opinion without further investigations, unnecessary consult). Results: There were 1916 consultations reviewed, with 52% of calls (n=991) originating outside of our hospital, and 72% (n=1387) coming from an emergency department. Cranial cases made up 64% (n=1230) of consults, while the remaining 36% (n=688) were spine cases. The mean patient age was 60.1±0.4 years. In multinomial logistic regression analysis, age, geographical distance of consulting site, and consult specific variables (neurosurgical subspecialty, inside vs. outside call, emergency department vs. inpatient ward or private office) were associated with consult disposition (p < 0.001). Conclusions: This study provides a descriptive analysis of neurosurgical consultations in Nova Scotia. Results from this study may be used to address inefficacies in the neurosurgical consultation process, including targeted education for consulting physicians.

Background: Stroke incidence is rising among younger adults (≤65yrs). Modifiable and behavioural risk factors are linked to stroke; however, limited understanding of knowledge and behaviour exists around preventative/lifestyle medicine (LSM) among this patient population. Study aim was to assess younger adult stroke patients’ lifestyle knowledge, habits, and barriers. Methods: A cross-sectional design was employed. Data were collected through an online, self-reported survey following a routine stroke prevention clinic visit and analyzed using descriptive and inferential statistics. Results: Sample included 103 participants (56.3% women, 60% white, mean age 47.6, 54.5% prior stroke). Majority (63%) understood current healthy lifestyle recommendations around blood pressure, sleep, and alcohol use, but fewer (<24.3%) around exercise and diet. Almost 70% ate processed food weekly, with emotions and social/family situations influencing eating habits. Interestingly, despite not understanding the current recommendations, >80% exercised moderately (3.5d/wk) with work and family responsibilities as main barriers. Over 50% slept <7hrs/night, had moderate to high stress levels, and implemented different coping strategies (food, TV, video games, and exercise). Majority (82.4%) reported willingness to change habits. Conclusions: Our findings provide valuable insight on young adult stroke patients’ preventative/LSM-related knowledge, habits, and barriers and provide new opportunities for the development of brain care-related initiatives.

The objective of the current study was to evaluate the effects of breed and genomic inbreeding on 305-day lactation yields of milk, fat and protein; and fertility traits of pasture-based dairy cows in Argentina. The genomic inbreeding and heterozygosity of 890 first-lactation cows and 27 bulls were calculated through methods based on the genomic relationship matrix and run of homozygosity using 44 174 single-nucleotide polymorphisms. Cows were classified into four breed groups: Holstein, Holstein crossbred, Holstein–Jersey crossbred and Jersey crossbred. The effect of genomic inbreeding was not significant on production traits, but inbred cows increased 3.0 days calving to conception interval (CCI) per 1% genomic inbreeding. On average, purebred Holstein cows produced 1119 kg milk, 22 kg fat and 30 kg protein more than Jersey crossbred cows. In the case of the fertility traits, Jersey crossbred cows had 45 days shorter CCI than purebred Holstein cows. A possible reason for the non-significant effects of genomic inbreeding of production and fertility traits is that these effects were evaluated in a crossbred population in which rates of heterozygosity would operate to some extent in the opposite direction to rates of genomic inbreeding.

Background: For treatment of high-grade gliomas (HGGs), subtotal resection (STR) may be preferred to minimize injury to eloquent areas. We aimed to characterize neurologic deficits developed in STR patients within the first month post-operatively and to establish a potential threshold for a safe volume of residual tumor to avoid neurological worsening. Methods: This is a single institution retrospective chart review, with 146 charts reviewed and 78 patients deemed eligible. Preoperative deficits and postoperative neurological deficits presenting prior to 1 month after surgery were captured. Imaging features such as tumour volume, edema, and other pertinent imaging characteristics were collected from preoperative and postoperative imaging. Results: Most patients that developed a postoperative deficit presented with motor deficits (55.1%), while only 1.3% of patients developed new or worsening tremor after surgery. On average, in patients with a new deficit, 26.5% of tumor was resected, and all patients had more than 19% of residual tumor. Conclusions: Postoperative neurologic deficits may develop after a subtotal resection when an average of 73.5% of tumor remains. The proposed threshold for tumor resection is greater than 26.5% to minimize the potential of neurologic worsening 1 month postoperatively.

We report the case of a female neonate admitted to the neonatal ICU with a rapid, narrow-complex tachyarrhythmia determined to be supraventricular tachycardia. Multimodality imaging and genetic testing confirmed a diagnosis of tuberous sclerosis complex with multiple cardiac rhabdomyomas. At 13 days of age, the patient was readmitted, exhibiting recurrent supraventricular tachycardia non-responsive to first-line treatment. Management required triple-drug therapy, whereafter the patient remained stable without recurrences. This is a rare report of supraventricular tachycardia in a functionally normal heart with the occurrence of supraventricular tachycardia due to structural abnormalities, with the possibility of multiple concealed accessory pathways.

Background: Reducing oral corticosteroids (OCS) use can alleviate the risk of many adverse events related to long-term OCS use. Here, we evaluate real-world utilization of OCS among patients with generalized myasthenia gravis (gMG) over the first 6 months following efgartigimod initiation. Methods: Patients with gMG using OCS who initiated efgartigimod treatment were identified retrospectively from an open US medical and pharmacy claims database (IQVIA Longitudinal Access and Adjudication Data [LAAD], April 2016-April 2023). Average daily dose (ADD) of OCS was analyzed during the 3-month period preceding efgartigimod initiation, and at 3 and 6 months post-efgartigimod initiation. Results: Of 231 patients assessed, 17 (7.4%), 109 (47.1%), and 105 (45.5%) had baseline OCS ADD of 0–5 mg, 5–20 mg, or >20 mg, respectively. At 3 and 6 months post-efgartigimod, 82 (35%) and 99 (43%) patients, respectively, reduced ADD by ≥5 mg. Proportion of patients with ADD of 0–5 mg increased >3-fold (7% baseline vs. 26% 6 months post-efgartigimod) and proportion of patients with ADD of >20 mg decreased by 35% (45% baseline vs. 29% 6 months post-efgartigimod) following efgartigimod initiation. Conclusions: Approximately 43% of patients were able to decrease steroid use or achieved steroid-free status within 6 months of efgartigimod treatment initiation.

Background: Pedicle screw fixation is an important technique in spine surgery. Violation of the pedicle can lead to neurovascular injury. Due to excellent pose repeatability, robotic technology may improve accuracy. Existing surgical spine robots use surgical assist architecture. This work explores the performance of a supervisory-control architecture robot (8i Robotics) for autonomous pedicle instrumentation. Methods: 3 porcine subjects underwent pedicle instrumentation utilizing the 7dof robot and were observed for 24 hours. Post-operative CT assessed screw location. Screws were graded clinically with the Gertzbein-Robbins Scale (GRS). Precision was assessed by a customized image processing pipeline. Euclidean error was calculated at screw head and screw tip. All points were normalized to a nominal screw, and confidence ellipses generated. Results: All animals were neurologically intact at 24 hours. All screws where GRS A. Mean tip and head Euclidean error where 2.47+/−1.25mm and 2.25+/-1.25mm respectively. Major and minor axes of the confidence ellipse at 99% was 2.19mm, and 1.28mm, and 2.07mm, and 0.42mm for tip and head respectively. Conclusions: 100% of screws obtained satisfactory clinical grading, with intact function in all animals post-operatively. This shows the capability of a supervisory-controlled 7DOF robot with OCT registration. Further investigation is warranted to further explore robotic capabilities, safety, and cost effectiveness.

Background: The Partial Labyrinthectomy Petrous Apicectomy (PLPA) aims to give transpetrosal access whilst preserving hearing for challenging tumors such as petroclival meningioma. There are few studies assessing resection and morbidity and no large studies that document hearing preservation and quality of life (QOL). We present the first large series to do so. Methods: A retrospective review was performed of all PLPA cases between 2005 and 2023 at a tertiary center. Demographics, tumor characteristics, neuromonitoring, hearing and surgical outcomes were collected. QOL was measured with the 36-item short form survey (SF-36). Results: Of 73 PLPAs, data for 56 patients undergoing 57 surgeries was obtained. Petroclival meningioma (57.8%) and epidermoid tumors (21.0%) were common indications . The mean patient age and tumor size were 51.6 years and 44mm. Gross total resection was achieved in 40.3%, near total in 15.8% and subtotal in 43.8% of cases with no perioperative mortality and was not influenced by attempted hearing preservation (p=0.183). Of 39 hearing preservation cases, 27 (69.2%) were preserved, 10 (25.6%) were lost and 2 had unclear outcomes. Conclusions: Improved microsurgery and neuromonitoring during PLPA leads to decreased mortality and morbidity compared to historical cohorts while achieving a high rate of resection, hearing preservation and maintained QOL.

Background: This retrospective study assessed the efficacy and tolerability of sulthiame as a treatment in children with epilepsy. In Canada, sulthiame is only available through Health Canada’s Special Access Program. Methods: Patients who received sulthiame at the Montreal Children’s Hospital from April 2012 to March 2023 were included. Patients’ medical charts were reviewed, and clinical data was extracted from neurology clinic notes and electroencephalogram (EEG) reports. Efficacy was assessed by comparing seizure frequency and frequency of EEG epileptiform abnormalities before and after initiating sulthiame, while also noting any reported changes in cognition or behaviour. Results: Sixteen patients were included (10 males, 6 females), all of whom had drug-resistant epilepsy and continuous spike-wave in sleep (CSWS) on EEG. Sulthiame starting dose ranged from 0.74 to 6.75 mg/kg/day. Improvement, either in terms of seizure control, cognition, or reduction in EEG epileptiform abnormalities, was reported in 8/16 children (50%). Two patients (13%) became seizure free, while three more (19%) had reduced seizure frequency. Three other patients (19%) had reported improvements in concentration, learning abilities or behaviour. No serious adverse event was reported. Conclusions: These data indicate that sulthiame is effective and well-tolerated in children with CSWS, regardless of the etiology and type of epilepsy.

Sulfosalt assemblages in a specimen from the Boliden Au–Cu–(As) deposit in northern Sweden, comprise micrometre to nanometre scale intergrowths of Se-rich izoklakeite and tintinaite with average formulae and calculated homologue number (N) given as: (Cu1.88Fe0.18)2.06(Pb22.92Ag1.47Cd0.01Zn0.01)24.41(Sb13.12Bi8.69)21.8(S50.19Se6.43Te0.12)56.73, N = 3.83, and (Cu1.31Fe0.74)2.05(Pb10.58Ag0.18Cd0.05Zn0.02)10.83(Sb10.2Bi5.23)15.43(S32.22Se2.46)34.7, N = 2.05, respectively. Tintinaite coexists with (Bi, Se)-rich jamesonite. High-angle annular dark field scanning transmission electron microscopy (HAADF STEM) imaging reveals chessboard structures comprising PbS and SnS modules with the number of atoms in the octahedral (M) sites counted as: n1 = 18 and n2 = 8 for tintinaite and n1 = 30 and n2 = 16 for izoklakeite. The homologue number can be calculated using the formula: N = (n1/6)–1 and N = n2/4 for PbS and SnS modules giving NTti = 2 and NIz = 4. A new N = 3 homologue, defined by n = 12 and n = 24 SnS and PbS modules, respectively, is identified as single or double units within areas with intergrowths between kobellite and izoklakeite. HAADF STEM imaging also reveals features attributable to lone electron pair micelles within the Sb-rich kobellite homologues. Atomic-resolution EDS STEM chemical mapping of Pb–Bi–Sb-sulfosalts shows a correlation with crystal structural modularity. The maps also highlight sites in the SnS modules of tintinaite in which Sb > Bi. Coherent nanoscale intergrowths between tintinaite and izoklakeite define jigsaw patterns evolving from chessboard structures and are considered to have formed during co-crystallisation of the two phases. Displacement textures and crosscutting veinlets (a few nm in width) are interpreted as evidence for superimposed syn-metamorphic deformation and are associated with the redistribution of Bi and Se. Imaging and mapping using HAADF STEM techniques is well suited to characterisation of Pb–Sb–Bi-sulfosalt phases, offering largely untapped potential to unravel the evolution of chessboard structures with applications across mineralogy but also extending into allied fields.

Background: Tethered cord syndrome, a condition in which the spinal cord stretches as a child grows, can cause various clinical symptoms. Occult TCS (OTCS) is a condition where a child displays some or many clinical symptoms of TCS, but no radiographic abnormality confirms the presence of a tethered cord (1-4). Diagnosis of OTCS in children is invasive and multi-factorial. The current diagnostic approach involves three main factors- clinical signs and symptoms, radiographic evidence, and motor evoked potentials (MEPs) tested under general anesthesia. Transcranial magnetic stimulation (TMS) is a non-invasive testing method for OTCS. It can replace MEPs, which are conducted under general anesthesia. Methods: We will conduct a case-control series of children at our center who have undergone TMS. We will characterize the children who have TCS and suspected OTCS and detail the children’s current diagnosis methods and outcomes in a technical note. We will then compare their pre-operative and post-operative data. Results: So far, we have conducted TMS on 10 children to help diagnose occult TCS. Conclusions: This approach is a novel and effective way to improve the accuracy of diagnosis in children, potentially preventing unnecessary surgery, or detecting patients who would otherwise suffer from the condition.

Background: The end-of-life (EoL) phase of care is pivotal for glioblastoma (GBM) patients. While early integration of palliative care has shown benefits in various cancer types, its role in GBM care remains underexplored. This study aims to characterize EoL care patterns in GBM patients, assessing their temporal evolution, regional disparities, and socioeconomic influences. Methods: This is retrospective study of all patients with GBM treated in Ontario between 1994 and 2018 using the ICES data repository. Variables analyzed included patient demographics, comorbidities, palliative care utilization, and aggressive/supportive care components. Results: We identified 9,013 GBM patients within the study period. There was a gradual increase in palliative care utilization over time, accompanied by a decrease in in-hospital deaths. However, the proportion of patients receiving chemotherapy in the last 14 days of life increased. Multivariate logistic regression found socioeconomic status influenced palliative care access and rural patients also had a higher rate of in-hospital deaths, possibly due to limitations in outpatient palliative care services. Conclusions: The findings in this study clarify the status of EoL care for GBM patients within Ontario, and demonstrates key areas for future research, underscoring the need for standardized EoL care practices to enhance the quality of care for GBM patients.

Background: Minimally invasive endoscopic techniques via the transorbital approach (ETOA) have emerged as a promising alternative for addressing skull base tumours. This study aims to showcase our institution’s extensive experience with ETOA, detailing the surgical technique employed and presenting comprehensive patient outcomes. Methods: A retrospective analysis was conducted on data from patients who underwent ETOA within the past five years. Results: Over the study period, 24 ETOA procedures were performed on 21 patients, with an average age of 48.92, 13 of whom were women. The superior orbital corridor was utilized in 95.83% of cases, and in 79.17%, ETOA was complemented by a transnasal approach. Spheno-orbital meningioma accounted for the most common surgical indication (33.33%, n=8), all resulting in vision improvement, followed by lateral frontal sinus mucocele (25%, n=6). The median length of stay was one day, and ETOA achieved the procedure goal in 19 patients. Transient V1 numbness was the primary complication (29.17%, n=7), and 20.83% (n=5) necessitated another surgery. Notably, no mortality was associated with this procedure. Conclusions: Our institution’s experience underscores the notable safety and efficacy potential of ETOA, with 19 out of 21 patients exhibiting positive outcomes, obviating the need for revision surgery in most cases.

Background: Bi-directional brain interfacing (closed loop DBS) is a modern focus of neuroengineering research. Most current clinical systems are open loop, allowing one way communication from the IPG battery to the brain. Bi-directional systems allow both stimulation and recording of neural activity (local field potential, LFP). The system algorithm can measure known pathologic LFPs to guide change in stimulation. However, recording LFPs from the brain encounters electrical artifact from the heart. Reducing artifact is imperative to accurate measurement of neural activity. Artifact will cause the bi-directional system to miscalculate stimulation parameters. This project evaluated reduction of artifact by moving the IPG further away from the heart in a device implanted into the skull. Methods: LFP data from ongoing clinical trials was collected and analysed for artifact using open source code. Anatomic targets include STN, PPN, CMT, and PAG. Results: Cardiac artifact is reduced in skull mounted DBS as shown by power spectral density of LFPs in each region. Conclusions: This project shows the importance of surgical placement of DBS sensing devices to reduce cardiac artifact in bi-directional brain interfacing. This has important engineering and surgical design implications for safety and performance as the field of closed loop DBS transitions from research to clinical settings.

Background: Parkinson’s disease (PD) varies widely across individuals in terms of clinical manifestations and course of progression. We aimed to compare patterns of brain atrophy between PD clinical subtypes using longitudinally acquired brain MRIs. Methods: We used T1-weighted MRIs from Parkinson’s Progression Markers Initiative (PPMI) on 134 PD individuals and 60 healthy controls with at least two MRIs. Patients were classified into three clinical subtypes at de novo stage using validated subtyping criteria based on major motor and non-motor classifiers (early cognitive impairment, RBD, dysautonomia): mild-motor predominant (n=74), intermediate (n=44), and diffuse-malignant (n=16). Deformation-based morphometry (DBM) maps were calculated and mixed effect models were used to examine the interaction between PD subtypes and rate of atrophy across brain regions over time, controlling for sex and age at baseline. Results: Individuals with ‘diffuse malignant’ PD showed a significantly higher rate of atrophy across multiple brain regions, including lateral nucleus of the forebrain, precuneus, paracentral lobule, inferior temporal gyrus, fusiform gyrus, and lateral hemisphere of the cerebellum (FDR corrected p<0.05). Conclusions: We demonstrated an accelerated atrophy pattern within several brain regions in ‘diffuse malignant’ PD subtype. These findings suggest the presence of a more diffuse multidomain neurodegenerative process in a subgroup of people with PD, favoring the existence of diverse underlying pathophysiologies.

Background: Efgartigimod is a human IgG1 antibody Fc fragment recently approved by Health Canada for patients with acetylcholine receptor antibody positive (AChR-Ab+) generalized myasthenia gravis (gMG). We assessed cost-effectiveness of efgartigimod vs chronic IVIg for adult patients with AChR-Ab+ gMG. Methods: A Markov model estimated costs (treatment and administration, disease monitoring, complications from chronic corticosteroid use, exacerbation and crisis management, adverse events, end-of-life care) and benefits (quality-adjusted life-years [QALYs]). The analysis was conducted from the Canadian healthcare system perspective. Health state transition probabilities were estimated using data from ADAPT, ADAPT+, and a network meta-analysis comparing efgartigimod with chronic IVIg. Utility values were obtained from MyRealWorld MG. Patients with MG-ADL ≥5 who did not die/discontinue were assumed to receive treatment every 4 weeks or every 3 weeks over the lifetime horizon. Results: Over the lifetime horizon, efgartigimod and chronic IVIg were predicted to have total discounted QALYs of 16.80 and 13.35, and total discounted costs of $1,913,294 and $2,170,315, respectively. Efgartigimod dominated chronic IVIg with incremental QALYs of 3.45 and cost savings of $257,020 over the lifetime horizon. Conclusions: Efgartigimod may provide greater benefit at lower costs than chronic IVIg for Canadian patients with AChR-Ab+ gMG, with substantial healthcare system savings over the lifetime horizon.

Background: Neurofibromatosis 1 is a multisystem, neurocutaneous disorder with a predisposition for various malignancies. There is no established care pathway or multidisciplinary clinic for adult patients with NF1 in British Columbia (BC). Patients may miss timely screening or therapeutic interventions. The development of new therapies for NF1 highlights the urgency for coordinated care. Methods: A review of existing programs and guidelines was conducted. The estimated population with NF1 in BC was determined. A working group consisting of neuromuscular neurology, pediatric neuro-oncology, adult neuro-oncology, and medical genetics identified gaps in care. Results: Approximately 2200 adult individuals with NF1 are estimated to live in BC. A three-prong approach to address identified gaps was developed: A quarterly multidisciplinary NF Case Conference was initiated. The initial session was attended by 18 providers. Focus groups for patients and providers to enhance understanding of both perspectives are being conducted. Informed by the focus groups, an NF1 Care Pathway for BC will be developed. Conclusions: Advances in treatment for NF1 prompted the formation of the BC NF Working Group to develop a strategy to improve longitudinal, multidisciplinary care. The development of a care pathway, with patient input, will improve care coordination and access to care.