Background: The Artery of Percheron (AOP) is a rare anatomic variant that supplies the bilateral medial thalami from a common origin; occlusion results in a characteristic pattern of bilateral thalamic infarction seen on neuroimaging. To date, we have not identified any cases in the literature describing corresponding ischemic changes seen on hyperacute CT Perfusion imaging. We aimed to characterize perfusion abnormalities seen in AOP occlusion by describing a case presentation, highlighting the importance of recognizing this syndrome clinically, and radiologically, in an acute stroke presentation. Methods: Description of a case, and literature search on PubMed. Results: A 74-year-old man was seen in the ER as a Code Stroke protocol with acute alteration of level of consciousness (LOC). ER assessment showed no focal abnormalities and was significant only for disorientation. CT/CTA/CTP initially appeared unremarkable for acute abnormalities. His LOC deteriorated requiring intubation, and subsequent MRI showed bilateral thalamic infarction. Further CT Perfusion review demonstrated increased Mean Transit Time and decreased Blood Flow without Volume abnormalities in the bilateral paramedian thalami. Conclusion: AOP infarction is an uncommon cause of bilateral thalamic infarction. We have demonstrated a case highlighting perfusion abnormalities not previously reported in AOP occlusion, illustrating the importance and utility of advanced CT perfusion imaging whilst considering less common stroke syndromes.

Background: Ischemic stroke secondary to NBTE is a rare complication of systemic malignancies. Although previously reported in gynecological cancers, this occurrence is infrequent. Furthermore, stroke pre-dating the gynecological malignancy diagnosis has rarely been reported. Methods: Case presentations and literature review. Results: Case1: A 48-year-old woman presented with acute dysarthria and left facial weakness caused by a right middle cerebral artery (MCA) infarct. Mitral valve vegetations were found on a transthoracic echocardiogram (TTE). A malignancy screen uncovered a pelvic endometrial adenocarcinoma. Case 2: A 49-year-old woman developed acute right hand weakness. A CT head scan showed a left pre-central gyrus infarct. Her TEE revealed aortic valve vegetations. An ovarian neoplasm was then discovered. Case 3: A 36-year-old woman with a known diagnosis of cervical squamous cell carcinoma developed acute left-sided weakness secondary to a right MCA stroke. Aortic valve vegetations were seen on TTE. Conclusions: We have reported three cases of NBTE where the underlying malignancy was gynecological. In the first two cases, the malignancy was discovered while investigating for the stroke mechanism, while the third had a known underlying malignancy. This series highlights the need to consider gynecological malignancies as an underlying cause of stroke in young women; and that the ischemic event can occur prior to the malignancy diagnosis.

Background: Whole-slide scanning of tissue sections spatially informed by imaging studies offers the opportunity to reconstruct specimens for co-registration to 3D imaging data. Digital image analysis algorithms can be designed to analyze and reconstruct such specimens via electronic “pipelines”. Methods: A goal of the Canadian Atherosclerosis Imaging Network (CAIN) is to improve the assessment of carotid atheromatous disease through studies that inform clinical imaging with gold-standard data (plaque pathology). To achieve this, sectioned atheromas are manually annotated and analyzed by electronic algorithm for pathological features of interest. Resulting images are then reassembled in 3D for registration to ultrasound, CT, PET-CT and MRI studies. Results: Carotid endarterectomy specimens were sub-serially sectioned, stained, digitized and annotated manually and by electronic algorithms. Resulting 2D images were successfully rendered, reassembled and analyzed in 3D using ex-vivo micro-CT as a spatial reference. Furthermore, histology quantification using colour deconvolution was found to be preferred over hue-saturation-intensity methods 94.7-100% of the time in a blinded multiple rater study. Conclusion: Automated “pipelines” greatly facilitate 3D reconstruction in comparison to traditional slice-by-slice methods. Transformations spatially guided by pre-existing imaging data is not only faster, but has superior objectivity and fidelity. With embedded annotations, 3D pathology maps become a rich, micron-level, permanent digital pathological database for correlative studies.

Background: Nail-patella syndrome (NPS) is an inherited autosomal dominant disease, with an incidence of approximately 1 in 50,000. It ischaracterized by nail dysplasia, hypoplastic patellae, other bone deformities and open angle glaucoma. The phenotype is variable. Methods: Case report Results: A 66 year old male presented with complaints of mild loss of sensation in both feet with gradual proximal spread to his knees over the past decade. There was no history of pain, paresthesias, autonomic dysfunction or weakness. Examination showed pectus excavatum with symmetrically dystrophic fingernails. Sensation to crude touch, pain and temperature were reduced up to mid shin, and vibration sense was diminished till the malleoli symmetrically. Electrophysiologic studies revealed a mild to moderate length-dependent polyneuropathy of axonal type. Detailed blood screening studies were negative. Genetic testing revealed the diagnosis of nail-patella syndrome with LMX1B gene mutation on chromosome 9q34. The lack of an identifiable acquired cause and the symmetric, slowly progressive and “painless” nature of the patient’s peripheral neuropathy point toward an inherited etiology. Conclusion: We present a case of slowly progressive sensorimotor axonal polyneuropathy in a patient with a diagnosis of NPS, which has not been previously reported. Peripheral nervous system disorder may be a variable phenotypic manifestation of LMX1B gene mutation.

Background: Resting state functional MRI (rs-fMRI) provides many advantages to task-based fMRI in neurosurgical populations, foremost of which is the lack of the need to perform a task. Many networks can be identified by rs-fMRI in a single period of scanning. Despite the advantages, there is a paucity of literature on rs-fMRI in neurosurgical populations. Methods: Eight patients with tumours near areas traditionally considered as eloquent cortex participated in a five minute rs-fMRI scan. Resting-state fMRI data underwent Independent Component Analysis (ICA) using the Multivariate Exploratory Linear Optimized Decomposition into Independent Components (MELODIC) toolbox in FSL. Resting state networks (RSNs) were identified on a visual basis. Results: Several RSNs, including language (N=7), sensorimotor (N=7), visual (N=7), default mode network (N=8) and frontoparietal attentional control (n=7) networks were readily identifiable using ICA of rs-fMRI data. Conclusion: These pilot data suggest that ICA applied to rs-fMRI data can be used to identify motor and language networks in patients with brain tumours. We have also shown that RSNs associated with cognitive functioning, including the default mode network and the frontoparietal attentional control network can be identified in individual subjects with brain tumours. While preliminary, this suggests that rs-fMRI may be used pre-operatively to localize areas of cortex important for higher order cognitive functioning.

Background: There exists the role for novel agents in the management of refractory intracranial pressure (ICP) via targeting cerebral acidosis, hyperemia, and excitotoxicity. Objective: We performed 4 separate systematic reviews to determine the effect of tromethamine (THAM), indomethacin, and ketamine on ICP. Methods: All articles from MEDLINE, BIOSIS, EMBASE, Global Health, HealthStar, Scopus, Cochrane Library, the International Clinical Trials Registry Platform (inception to: February 2014 – THAM, July 2014 – Indomethacin, November 2013 - Ketamine), and gray literature were searched. The strength of evidence was adjudicated using both the Oxford and GRADE methodology. Results: Twelve articles were reviewed utilizing THAM while documenting ICP in neurosurgical patients. All but one study documented a decrease in ICP. Twelve original articles were reviewed utilizing indomethacin for ICP in neurological patients. All but one study documented a decrease in ICP. Seven articles were reviewed utilizing ketamine, documenting ICP in TBI patients, with 16 in non-trauma neurological patients. ICP did not increase in the studies during ketamine administration, and trended to decrease ICP. Conclusion: There exists Oxford level 2b, GRADE B evidence that THAM reduces ICP in the TBI and malignant ischemic infarct population. There exists Oxford level 2b, GRADE C evidence that indomethacin and ketamine reduce ICP in the adult severe TBI population.

Background: The diagnosis of a concussion is often dependent on the athlete self-reporting their symptoms. It has been suggested that improving athlete’s knowledge and attitudes towards concussions may increase self-reporting behavior; however, research in this area is inconclusive. The objective of this study is to determine if a Concussion-U educational presentation improves knowledge and attitudes of youth hockey players towards concussions. This is part of a larger study designed to determine the impact of an informational presentation on the knowledge and attitudes over a full hockey season. Methods: 56 elite male Bantam and Midget hockey players (mean age=14.52±1.13 years) were recruited from the local community. Each participant completed a modified version of Rosenbaum and Arnett’s Concussion Knowledge and Attitudes Survey (RoCKAS) questionnaire immediately before and after a Concussion-U educational presentation on the subject. Results: Concussion knowledge and attitude scores significantly (p<.001) increased from pre-presentation to post-presentation by 13.1% and 8.7%, respectively. Discussion: A Concussion-U educational presentation designed to improve concussion knowledge and attitudes in youth hockey players resulted in increased knowledge and improved attitudes towards concussion in elite male Bantam and Midget hockey players. Future research should examine the long-term effects of such presentations.

Background: Traumatic brain injury (TBI) is the leading cause of traumatic death and disability, and most TBIs are treated in the Emergency Department (ED). We examined the incidence and epidemiological patterns of TBIs presenting to Ontario EDs over an eight-year period. Methods: All TBI-related ED visits between April 2002 and March 2010 were identified using a population-based database that is mandatory for ambulatory care facilities in Ontario. Incidence rates were reported across multiple strata, including age group, sex, and mechanism of injury. Results: From 2002-2010, there were 1,032,249 ED visits for TBI in Ontario. Peak rates occurred among young children ages 0-4 (349 per 10,000) and elderly adults ages 85+ (243 per 10,000). Overall, males experienced a 53% greater rate of TBI compared to females. Falls (47%), motor vehicle crashes (MVC; 10%), and sports-related injuries (9%) were the most common causes of TBI. The highest rates of TBI-related falls, MVCs, and sports-related injuries occurred among young children (0-4) and elderly adults (85+), adolescents/young adults (15-24), and children (5-14), respectively. Conclusions: Our study reveals a substantial health system burden associated with TBI in the ED setting, underscoring the need for enhanced surveillance and prevention efforts targeted to vulnerable demographic groups.

Background: Traumatic brain injury (TBI) is a leading cause of death and disability, yet there is limited research on its economic burden. We estimated the incidence and lifetime costs of TBI identified in the Emergency Department (ED) in Ontario, Canada between April 2009 and March 2010. Methods: ED visits for TBI were identified using a population-based database that is mandatory for ambulatory care facilities in Ontario. The authors calculated unit costs for medical treatment and productivity loss, and multiplied these by incidence estimates to determine the lifetime costs of identified TBI cases. Results: In 2009, there were over 133,000 ED visits for TBI in Ontario, resulting in a conservative estimate of $945 million in total lifetime costs. Costs were greater for males than females across nearly all age groups, with males incurring two-fold higher costs overall. Together, falls ($407 million), struck by/against ($309 million), and motor vehicle injuries ($161 million) represented 93% of lifetime costs associated with TBI. Conclusions: This study revealed a high incidence and economic burden associated with TBI identified in the ED. More research is needed to fully appreciate the burden of TBI across a variety of healthcare settings.

Background: Violence is a frequent occurrence in ice hockey and has been associated with an increased risk of injury. Methods: Case-control study. The study population consisted of youth aged 0-19 years who presented to a participating emergency department (ED) with an injury resulting from participation in ice hockey. In order to examine the outcomes following brain injuries in ice hockey, the outcome was admission to the hospital (cases) or discharge from the ED (controls). In order to examine the relationship between brain injury and violence, the outcome was brain injury (cases) or a non-brain injury (controls). Logistic regression was used to determine the associations controlling for potential confounders. Results: In total, 56,835 youth suffered an injury related to ice hockey. 11.0% (n=6,293) were brain injuries. Youth who engaged in violence were at significantly higher odds of sustaining a brain injury as opposed to an injury to another body part (OR: 1.67; 95% CI: 1.55-1.80). Youth who sustained violence-related injuries were at significantly higher odds of being admitted to the hospital compared to youth who sustained non-violence related injuries (OR: 2.34; 95% CI: 1.49-5.68). Conclusions: Youth who engage in violence are at higher odds of sustaining a brain injury and of being admitted to the hospital.

Background: Rugby is a high-intensity, full-body contact sport in which there is an increased risk of injury associated with participation. The objectives of this study were to identify the mechanisms and characteristics of rugby-related injury sustained amongst Canadian youth. Methods: Data were obtained from the Canadian Hospitals Injury Reporting and Prevention Program database. The study population consisted of individuals aged 10-19 who sustained an injury while participating in rugby between the years 1990 and 2014. Proportions of body parts injured, mechanisms of brain injury, and nature of injury were calculated with 95% confidence intervals. Results: There were a total of 6200 rugby-related injuries sustained among individuals aged 10-19 between the years 1990 and 2014. 16.0% (N=993) of all injuries were brain injuries, 48.9% (n=486) of which were concussions. 70.7% (n=4838) of all injuries were sustained by males. The predominant mechanism of brain injury was tackling which accounted for 48.3% of all brain injuries n=480. Conclusion: Participation in rugby is rapidly increasing, and brain injury as a result of participation is a common occurrence. Possible changes to reduce injury include stricter penalties for high tackles to the head and neck area, and rules against blindside tackles.

Background: Pupillometry, the measurement of pupil response dynamics via the pupillary light reflex, is seldom used in the assessment of mild traumatic brain injury (mTBI). We hypothesized that there would be quantifiable differences in detailed pupil response measurements in patients with acute and chronic mTBI. Methods: We conducted 49 bilateral pupillometry measurements, in acute mTBI patients at 1-week (N=11), 2-4w (N=9), and 3-7mo post-injury (N=3); 14 patients with persistent post-traumatic symptoms (PTS) once, and healthy controls across a first visit (N=7) and second visit 2-4w later (N=5). Results: The percentage of left pupil diameter change was significantly greater in the acute mTBI group at second visit (mean=36.3% (2.96)), compared to controls at second visit (mean=31.6% (4.39)) (F=5.87, p=0.0321). We did not identify significant differences between acute mTBI patients and controls at first visit, PTS patients versus controls, and within the acute mTBI group across three longitudinal visits. Conclusion: While these preliminary data suggest that pupillometry under these conditions does not distinguish between patients who had a recent mTBI or those with PTS and healthy controls, further research is warranted investigating pupil behavior and its clinical utility in mTBI.

Background: TBI is a leading cause of death and disability. Management based on the BTF guidelines is widely accepted and thought to improve outcome. The objectives of this study were: 1) to review the rate of adherence to BTF guidelines; 2) to identify factors influencing adherence; and 3) to determine the effect of guideline-based management on outcome. Methods: We searched all electronic bibliographic databases. In duplicate and independently, two investigators screened titles, abstracts and articles to select appropriate studies reporting compliance rate, factors influencing compliance, and adjusted mortality or morbidity. Data extraction and assessment of bias risk were performed independently by both investigators. We excluded pediatric and military-related TBI studies. Results: A total of 30 articles met inclusion/exclusion criteria out of 1153 papers screened. Most are retrospective and cross-sectional observational studies; there were no randomized control trials. Preliminary analysis showed considerable variation in compliance rate with BTF guidelines ranging from 5.6-96%. Conclusions: Variation in the care of TBI patients persists across the world. Compliance with BTF guidelines was strongly influenced by implementing a guidelines-based protocol. Heterogeneity of the article prevents outcome assessment. Well-conducted study to support the existing literature of the beneficial effect of current guidelines is needed.

Background: Critically ill neurosurgical patients require expedient access to neurosurgical centers (NC) to improve outcome. In Ontario, many patients are initially evaluated at a non-neurosurgical center (NNC) and subsequently transferred to a NC by a provincial service using air or ground vehicles. We characterized transfers from NNC to NC for critically ill patients. Methods: A retrospective observational analysis was undertaken. The cohort included patients in Ontario with emergent and urgent neurologic pathologies who underwent transfer from a NNC to NC between January 1, 2011 and December 31, 2013. Timing, clinical, and geographic data were collected for each transfer. Results: We identified 1103 emergent/urgent transfers. The mean transfer time to a NC was 3.4hrs (SD – 3.0) and varied by the geographic region of origin. 17% of patients bypassed a closer NC during transfer to their destination NC. Transfers that bypassed a closer NC travelled further (162km vs. 477km, p<0.001), took longer (3.1hrs vs. 3.9hrs, p<0.001), and in some regions were associated with a higher risk of in-transit clinical decline (3.0% vs. 8.3%, p<0.05) when compared with transfers that ended at the closest NC. Conclusions: Transport time to a NC varied across Ontario. Transfers occasionally bypassed the nearest NC, which may reflect neurosurgical bed availability, resource limitations, or patient needs.

Background: Chronic subdural hematomas (cSDH) are a common neurosurgical problem with significant morbidity and mortality. Current treatment methods are variable. Post-operative subdural drain used in conjunction with burr-hole craniostomy may reduce recurrence. This study compared recurrence rates for cSDH between two surgical practices with and without use of post-operative subdural drain at the QEII Health Sciences Center. Methods: A retrospective chart review was conducted to compare recurrence rates between surgical patients treated with or without a post-operative drain between 1997- 2012. The primary endpoint was recurrence, defined as occurrence of symptoms due to hematoma confirmed by CT within six months of the original operation. Categorical frequencies were compared with chi square or Fisher’s exact test. Logistic regression was performed to identify risk factors for recurrence. Results: There were 85 patients (mean age 73 years; SD 13.0) who had burr-hole craniostomy. Age, cSDH volume, site, GCS, anticoagulation, drain, conservative treatment with steroids and perioperative steroids were not found to be independent predictors of recurrence. Recurrence occurred in 2 of 34 (5.9%) patients with drain, and in 7 of 51 (13.7%) without (p=0.305). There were insufficient data to compare mortality and complications. Conclusions: Use of post-operative subdural drain did not significantly alter the cSDH recurrence rate.

Introduction: Surgical removal is the standard treatment for Cushing’s disease. Although endoscopic transsphenoidal surgical (ETS) approach has grown in popularity, its efficacy has not yet been established. Furthermore, achieving long-term remission remains challenging. Methods: We conducted a retrospective chart review of 39 consecutive patients who underwent ETS for Cushing’s disease at our institution between 2005 and 2014. Univariate analysis using Pearson’s χ2 test was carried out on variables of patient demographics, radiology, pathology, biochemical markers versus recurrence. Results: The mean age was 40, with 82% females. Average length of follow-up was 44.8 months. Based on serum cortisol level, 28 patients (71%) achieved mid to long-term remission after ETS. Of them, 25 experienced an immediate remission, and 3 achieved a delayed remission as long as 4 months postoperatively. MRI findings of (1) microadenomas or no detectable abnormality, (2) adjacency to the cavernous sinus wall were associated with significantly higher recurrence rate (p<0.05). Histologically, MIB-1 >5% was not a significant variable (p=0.55). Conclusion: We found ETS resection to be an effective and safe procedure for majority of the ACTH-secreting adenomas, with remission rates >70%. Additionally, patients with microadenomas, negative preoperative MR, and cavernous sinus adjacency were less likely to achieve remission.

Introduction: Treatment of specific patterns of symptomatic hydrocephalus in the adult patient may be accomplished with endoscopic third ventriculostomy (ETV) as an alternative to insertion of a ventriculoperitoneal (VP) shunt. This review examines a single center experience with ETV to treat hydrocephalus in symptomatic adult patients. Methods: Adult patients (≥18 years) with a diagnosis of hydrocephalus who were treated with ETV in Calgary between January 1994 and July 2014 were reviewed using a clinic database and registry. Results: 163 patients were identified (male=92; female=71). Mean age at the time of ETV was 46.5 years (range 18-83.4 years). 118 underwent ETV as a primary treatment and 45 patients underwent treatment after presenting with VP shunt failure (secondary ETV). 113/163 patients had a diagnosis of aqueductal stenosis, 22/163 had a diagnosis of tumor. Mean followup was 8.2 years (range 0.3-18.4 years). Symptoms in 149/163 (91.4%) of ETV patients were better or unchanged at last followup. 104/118 (88.1%) of primary ETV patients were shunt free at last followup. 39/45 (86.7%) of secondary ETV patients were shunt free at last followup. Conclusion: Endoscopic (ETV) treatment is an effective long-term treatment for a select population of adult patients with hydrocephalus.

Introduction: Accurate diagnosis and classification of facial pain is critical for assigning surgical treatment, avoiding misdirected interventions and studying outcomes. We conducted a population-based longitudinal study of patients with facial pain and compared diagnostic classification systems. Methods: Medical records for all Manitobans presenting to our centre with a primary complaint of facial pain from 2001 to 2013 were reviewed. We then applied diagnostic criteria from the International Classification of Headache Disorders (IHS-3), the International Association for the Study of Pain (IASP) and Burchiel’s system for comparisons. Results: There were 534 patients with facial pain (3.4/100,000/year) and two-thirds of these had conditions potentially amenable to neurosurgical interventions. Our most common diagnoses were typical trigeminal neuralgia(50%), atypical trigeminal neuralgia(7%), idiopathic trigeminal neuropathy(7%), idiopathic facial pain(11%); average ages were 65±14(22-99), 60±18(32-86), 55±16(28-83) and 48±12(28-82) with a female proportion of 55%, 59%, 65% and 80%, respectively. Other classification systems included no criteria for idiopathic trigeminal neuropathy. The classifications of “trigeminal neuralgia type-1 and type-2” did not differentiate between surgical and non-surgical candidiates. Conclusion: Published classification systems of facial pain have differing criteria for diagnosis of trigeminal neuralgia and none defines a large group with idiopathic trigeminal neuropathy. This may lead to considerable variability in determinations of potential surgical candidates and comparing outcomes of treatment.

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 availability of virtual reality (VR) surgical simulators affords the opportunity to assess the influence of stress on neurosurgical operative performance in a controlled laboratory environment. This study sought to examine the effect of a stressful VR neurosurgical task on the subjective anxiety ratings of participants with varying levels of surgical expertise. Methods: Twenty four participants comprised of six staff neurosurgeons, six senior neurosurgical residents (PGY4-6), six junior neurosurgical residents (PGY1-3), and six senior medical students took part in a bimanual VR tumor removal task with a component of sudden uncontrollable intra-operative bleeding. State Trait Anxiety Inventory (STAI) questionnaires were completed immediately pre and post the stress stimulus. The STAI questionnaire consisted of six items (calm, tense, upset, relaxed, content and worried) measured on a Likert scale. Results: Significant increases in subjective anxiety ratings were noted in junior residents (p=0.005) and medical students (p=0.025) while no significant changes were observed for staff and senior neurosurgical residents. Conclusions: Staff and senior residents more effectively mitigate stress compared to junior colleagues in a VR operative environment. Further physiological correlates are needed to determine whether this increased anxiety is paralleled by physiological arousal and altered surgical performance.