Background: We describe a patient with recurrent subarachnoid hemorrhage (SAH) secondary to Chiari 1 malformation. Methods: A retrospective review of the clinical chart was performed. Results: A previously healthy female in her 70’s presented with worst headache of life. CT demonstrated 4th ventricular hemorrhage with SAH extending into the bilateral cerebellomedullary fissures. CTA did not show a vascular etiology and patient was discharged home. Incidental note was made of a right persistent trigeminal artery. The patient then represented 2 weeks later with worst headache of life and decreased level of consciousness. CT demonstrated extensive SAH extending into the 3rd and 4th ventricles. CTA and diagnostic cerebral angiogram did not show a vascular etiology. MRI brain/C-spine revealed Chiari 1 malformation. An external ventricular drain was placed but could not be weaned. She underwent suboccipital craniectomy with C1 laminectomy. Intraoperatively, there was a prominent dorsal spinal vein that appeared under tension as it pierced the arachnoid membrane and subsequently entering the dura as a rudimentary occipital sinus. This vein was coagulated and divided. The patient recovered well and was at neurological baseline at 6 month follow-up. Conclusions: This is the first reported case of recurrent SAH secondary to Chiari 1 malformation.

Background: Little data exists on the impact of metabolic acidosis in aneurysmal subarachnoid hemorrhage (aSAH). Given its detrimental effects in critically ill patients, we inquired whether in patients with aSAH, metabolic acidosis (bicarbonate <22mmol/L) was associated with an increased risk of worse outcomes at 3 months (mRS >2). Methods: We performed a retrospective analysis of the CONSCIOUS-1 randomized control trial dataset including all patients who had at least three bicarbonate levels drawn. Bivariate and multivariate logistic regression models were used to assess for independent relationship between metabolic acidosis and functional outcome at 3 months. Delayed cerebral ischemia (DCI) was assessed for potential effect modification. Results: Three hundred and nineteen patients were included in our analysis. There was no difference in the proportion of poor outcome between those with or without metabolic acidosis on bivariate analysis (OR=1.022, p=0.949). However, amongst individuals who develop DCI, there was increased odds of unfavorable outcome when patients developed metabolic acidosis (OR=7.588, p=0.023). Conclusions: Individuals who develop delayed cerebral ischemia may benefit from having their bicarbonate level carefully monitored. More studies are needed to determine how the development of metabolic acidosis can be mitigated, and whether its prevention leads to improved outcomes.

Background: Melanocytic tumors of the central nervous system (CNS) such as meningeal melanoma are exceedingly rare tumours derived from leptomeningeal melanocytes. Primary meningeal melanomas account for 0.1% of intracranial neoplasms with an incidence of approximately 0.5 per 10 million. Methods: We report the case of a previously healthy 47 year old male who presented with bilateral tonic-clonic seizure. Magnetic resonance imaging (MRI) demonstrated a homogenously-enhancing right temporal extra-axial lesion. The patient was stabilized on anti-epileptic medications and dexamethasone prior to proceeding with complete surgical resection of the lesion. Review of the current literature was conducted. Results: Macroscopically, the extra-axial lesion was heavily pigmented with invasion of the surrounding dura and skull. Histopathology revealed a poorly differentiated neoplasm with nuclear atypia and melanin-containing cells with strong SOX10 positivity and variable S100 positivity. Systemic workup was negative including absent ocular or cutaneous melanomas. Oncopanel was negative including absent BRAF mutation. He began checkpoint inhibitor therapy and subsequently developed cerebral venous sinus thrombosis (CVST) managed with anticoagulation. At 6 month follow-up, he was neurologically intact, working full-time, and had resumed immunotherapy. Conclusions: Primary intracranial melanoma is a rare tumour that can appear radiographically similar to meningioma. Surgical resection remains the mainstay of therapy for best long-term prognosis.

Background: Insertion of an external ventricular drain (EVD) is performed to treat elevated intracranial pressure. EVD catheters are associated with complications such as EVD catheter infection (ECI), intracranial hemorrhage (ICH) and suboptimal catheter placement. As part of the Canadian Neurosurgery Research Collaborative, we sought to investigate the national rate of such complications and their risk factors. Methods: Prospective study of 273 patients from eight academic Canadian neurosurgery centres Results: Infection rate was 6% and predicted by smaller incisions and not peri-procedure antibiotics, tunneling distance, type of antiseptic used or catheter flushing (p>0.05). The mean duration of EVD was 17.7±3.7 in ECI and ventriculitis group which was significantly higher than in patients without ECI (9.4±8.1) (p=0.045). Although the risk of developing ICH was 9.3%, symptomatic ICH was rare. Pre-procedure pharmacological DVT prophylaxis predicted EVD-related ICH(OR 4.73). The rate of suboptimal catheter location was 31% and predicted by the number of passes (p=0.02), but not image guidance, level of training or catheter placement in an operating room setting (p>0.05). Conclusions: This study reports EVD complication rates and their associated risk factors observed within an academic, multicentre Canadian cohort. This information will help to identify strategies to increase the safety of this common neurosurgical procedure.

Background: Anemia following aneurysmal subarachnoid hemorrhage (aSAH) has been associated with poor outcome, but complications from transfusion have limited aggressive management of anemic patients. This study examined the relationship between hemoglobin levels, transfusion and outcome following aSAH. Methods: We performed a post-hoc analysis of the CONSCIOUS-1 trial. Poor outcome was defined as a 3-month modified Rankin Scale > 2. Minimum hemoglobin levels were evaluated as predictors of outcome using logistic regression analysis, ROC curve analysis, and LOWESS curves. Propensity score matching was used to assess the effect of transfusion on poor outcome in patients with minimum hemoglobin levels between 70-90 and 80-100 g/L. Results: Lower minimum hemoglobin levels were associated with poor outcome on both univariate (p<0.001) and multivariate (p=0.012) analysis. Area under the ROC curve for minimum hemoglobin was 0.673. Youden index analysis found a minimum hemoglobin threshold of 91.5 g/L maximally predictive for good functional outcome. Propensity score matching showed a trend towards poor outcome in transfused patients with minimum hemoglobin levels between 70-90 and 80-100 g/L (p=0.052 and 0.09). Conclusions: This work suggests that decreasing hemoglobin is an independent predictor of poor outcome following aSAH. However, there was a trend towards poor outcome in transfused patients. The optimal transfusion threshold should be evaluated by prospective trials.

Orbital lymphaticovenous malformations (LVM) are congenital vascular lesions that are typically infiltrative in nature. There have been reports of orbital LVMs extending intracranially through orbital fissures, but there have been no reports of intradural extension that we are aware of. We present the case of an otherwise healthy 25-year-old female with an orbital LVM extending intradurally. Imaging revealed an intraorbital lesion extending through a bony defect in the medial orbital roof to the orbitofrontal cortex. A modified orbitozygomatic approach was used to obliterate this lesion. A durotomy was created to examine the intradural extension of the lesion, which appeared as a lobulated red vascular structure emanating from the dura along the roof of the orbit. This was gradually and comprehensively bipolar coagulated and subsequently obliterated. Neurosurgical and ophthalmological collaboration was used in the surgical management of this case. In summary, we report the first case of an orbital LVM extending intradurally, and provide pre and post-operative imaging as well as images captured through the intraoperative microscope. Through this case we highlight the importance of an interdisciplinary approach when managing orbital LVMs, as both ophthalmological and neurosurgical expertise were critical in the success of the surgery.

Background: No standardized method of resident operative-case logging exists. Our study sought to develop a standardized form used by residents to log operative-cases. Methods: Members of the Canadian Neurosurgery Research Collaborative (CNRC), a national resident-led research organization have created a standardized document based on the current Royal College objectives for operative procedures (section 5). Modifications to structure and content will be guided via consensus from Canadian neurosurgery program-directors. Results: Program directors in each CNRC collaborative institution will be asked to modify the standardized form. The CNRC currently involves thirteen of the fourteen Canadian neurosurgery residency programs. Additional consensus, if necessary, can be reached at the Royal College meeting for program directors of neurosurgery March 20th 2017. Conclusions: A standardized operative-case log represents the first step in a prospective study towards compiling operative volume of all Canadian neurosurgical residents over one academic year. Such data will be essential to guide informed decisions with regard to Royal College requirements as Canadian neurosurgical programs transition to a competency based framework.

Background: Communicating with senior neurosurgical colleagues during residency necessitates a reliable and versatile smartphone. Smartphones and their apps are commonplace. They enhance communication with colleagues, provide the ability to access patient information and results, and allow access to medical reference applications. Patient data safety and compliance with the Personal Health Information Protection Act (PHIPA, 2004) in Canada remain a public concern that can significantly impact the way in which mobile smartphones are utilized by resident physicians Methods: Through the Canadian Neurosurgery Research Collaborative (CNRC), an online survey characterizing smartphone ownership and utilization of apps among Canadian neurosurgery residents and fellows was completed in April 2016. Results: Our study had a 47% response rate (80 surveys completed out of 171 eligible residents and fellows). Smartphone ownership was almost universal with a high rate of app utilization for learning and facilitating the care of patients. Utilization of smartphones to communicate and transfer urgent imaging with senior colleagues was common. Conclusions: Smartphone and app utilization is an essential part of neurosurgery resident workflow. In this study we characterize the smartphone and app usage within a specialized cohort of residents and suggest potential solutions to facilitate greater PHIPA adherence

Background: The Canadian Neurosurgery Research Collaborative (CNRC) is a trainee-led multi-centre collaboration made up of representatives from 12 of 14 neurosurgical centres with residency programs. To demonstrate the potential of this collaborative network, we gathered administrative operative data from each centre in order to provide a snapshot of the operative landscape in Canadian neurosurgery. Methods: Residents from each training program provided adult neurosurgical operative data for the 2014 calendar year, including the number of surgeries in the subcategories cranial, spinal, and peripheral nerve. Because some residency programs have surgeries distributed among more than one hospital, we calculated mean case load per residency program and per hospital. Results: Interim results from 6 neurosurgery residency programs are presented (with data from other programs forthcoming). Overall, there were on average 2,352 operative cases per residency program (n=6) and 1,176 operative cases per adult hospital (n=12). Among 5 programs with more detailed operative data, the mean numbers of cranial, spinal, peripheral nerve, and miscellaneous surgeries per residency program were 757 (47%), 487 (30%), 47 (3%), and 319 (20%) respectively. Conclusions: We show as a proof-of-concept that a trainee-led nation-wide research collaborative can generate meaningful data in a Canadian context.

Background: The pathophysiology of subarachnoid hemorrhage (SAH) is complex and includes disruption of the blood-brain barrier (BBB). We freshly isolated BBB endothelial cells (BECs) by 2 distinct methods after experimental SAH and then interrogated their gene expression profiles with the goal of uncovering new therapeutic targets. Methods: SAH was induced using the prechiasmatic blood injection mouse model. BBB permeability studies were performed by administering intraperitoneal cadaverine dye injections at 24h and 48h. BECs were isolated either by sequential magnetic-based sorting for CD45-CD31+ cells or by fluorescence-activated cell sorting (FACS) for Tie2+Pdgfrb- cells. Total RNA was extracted and analyzed using Affymetrix Mouse Gene 2.0 ST Arrays. Results: BBB impairment occurred at 24h and resolved by 48h after SAH. Analysis of gene expression patterns in BECs at 24h reveal clustering of SAH and sham samples. We identified 707 (2.8%) significant differentially-expressed genes (403 upregulated, 304 downregulated) out of 24,865 interrogated probe sets. Many significantly upregulated genes were involved in inflammatory pathways. These microarray results were validated with real-time polymerase chain reaction (RT-PCR). Conclusions: This study is the first to investigate in an unbiased manner, whole genome expression profiling of freshly-isolated BECs in an SAH animal model, yielding targets for novel therapeutic intervention.

Background: After July 16, 1997, Royal College of Physicians and Surgeons of Canada (RCPSC) trainees in neurosurgery were no longer eligible for American Board of Neurological Surgeons (ABNS) certification. It was anticipated that this would lead to an influx of neurosurgeons in Canada. Methods: We analyzed historical Canadian Residency Matching Service (CaRMS) data for 1997–2014 for trends in neurosurgery residency positions offered, vacancy rates, resident demographics and other pertinent data. Results: A mean of 0.94% of medical students applied to neurosurgery as their first choice (range: 0.54%-1.79%). Comparing 2 consecutive time periods (1997–2005 vs. 2006–2014), the mean number of neurosurgery entry positions per year increased from 14 to 19, while mean applicant numbers increased from 24 to 28, respectively. Ninety-five percent of those accepted into neurosurgery ranked it as their first choice discipline and few candidates who ranked neurosurgery highest were unmatched. Women applying to neurosurgery as their first choice discipline were equally likely to match as men (84% vs. 85%) and comprised 28% of neurosurgery residents selected since 2008 (vs. 14% in 1997–2007). Conclusions: The number of neurosurgery CaRMS positions and applicants have increased since 1997. This will have implications for neurosurgical workforce planning and physician employment in Canada.

Background: The American Board of Neurological Surgeons (ABNS) made persons beginning neurosurgical training in Canada after 1997 ineligible for ABNS board exams and certification in the United States (US). We set out to track employment outcomes for graduates who are “ABNS ineligible.” Methods: Graduates from Canadian neurosurgical programs who began training from 1998 to 2008 (ABNS ineligible) were followed regarding their employment status (n=143). Data was obtained from public-domain websites and direct connections though Canadian Neurosurgical Society (CNSS) members. Association between pursuit of research during residency (MSc, PhD, or ≥ 2 years of non-degree research) and full employment was determined by Fisher’s exact test. Results: 60% and 26% of graduates currently have full-time staff positions in Canada and the US, respectively. “Underemployment,” defined as failure to secure a full-time position in neurosurgery despite a desire to do so (including locums, additional fellowship positions, unemployment and career changes) is currently seen in 12% of graduates, with 20% having been underemployed at some point within 5 years of graduation. Pursuit of research during residency was significantly associated with obtaining full employment (94% vs. 73%, p=0.011). Conclusions: Underemployment is a significant issue in recent neurosurgical graduates from Canadian training programs. Research training during residency appears strongly associated with obtaining full employment.