Background: The expansion of neuromodulation intervention for complex pain syndromes has been signifcant in the last few decades. Considering the increased load of patients, we thought about evaluating the level of awareness among different medical experts to help assessing their familiarity with spinal cord stimulator (SCS). Methods: Survey has been sent to general practitioners, family physicians, pain specialists and spine surgeons. The main outlets of the survey aims to assess the followings:

The main source of their knowledge about SC

Familiarity with candidates who may benefit from SC

Introducing the concept of SC to their patients as an adjunctive treatment

Frequency of patients’ referral for SC

Main reason for referring their patients

Familiarity with centres providing SCS

Results: EResults will be provided upon analysing the data from the collected surveys. Conclusions: The expansion in neurmodulation is expected to help patients with intractable pain syndromes. Hence, the survey would potentially help to explore the deficiencies in health workers awareness about SCS and outline future directions toward proper patients counseling and optimising their referral to neuromodulation centres.

Background: Cubital tunnel syndrome is the second most frequent upper extremity entrapment neuropathy. Various surgical approaches have been described in the literature for Ulnar nerve decompression, ranging from open In-situ decompression to endoscopic Ulnar nerve release. In this technical note we describe a new endoscopic approach for Ulnar nerve decompression. Methods: Four cadavers, a total of eight fresh arms were dissected using our new endoscopic technique. The technique involves a 2.5cm skin incision placed 2.5cm distal to the medial epicondyle, and perpendicular to the long nerve axis. Early identification of motor branches was achieved using this skin incision. Under endoscopic view using 30 degree rigid scope Ulnar nerves were decompressed Results: Early identification of motor branches was achieved using distally placed skin incision in all eight arms. Conclusions: The safety of identifying Ulnar nerve motor branches in the early steps of the procedure, and the avoidance of scar formation over the elbow joint are the proposed advantages of this approach. More clinical studies needed to validate this outcome.

Background: Hyponatremia has been found to be associated with increased complications in a variety of surgical populations. No study looked specifically at patients undergoing spine surgery. We also specifically address whether it has an effect on the typical low-risk patient admitted for degenerative spine disease, a population that forms the major bulk of clinical practice. Methods: Data was obtained from the American college of surgeons National Surgical Quality Improvement Program (ACS-NSQIP). All patients who underwent elective spinal surgery for degenerative disease from 2011 to 2013 were included. The two arms (normonatremic and hyponatremic) were then compared. Results: A total of 58049 patients were included, 3037 were hyponatremic. Hyponatremic patients were older and had more comorbidities. They also developed more minor and major complications. When all comorbidities were controlled for, hyponatremia was only associated with increased minor but not major complications. These patients were more likely to require a blood transfusion (OR=1.23, CI 1.10-1.43) and a prolonged hospital stay (OR=1.52, CI 1.33-1.75). Conclusions: This study finds an association between hyponatremia and postoperative adverse events in a low risk population that forms the major bulk of clinical practice. This addresses a potential target for quality improvement strategies with significant cost saving implications.

Background: Spinal computer-assisted navigation (CAN) is proven to increase instrumentation accuracy. Adoption remains limited by workflow restrictions, learning curves and costs. Here, we assess spinal CAN usage among Ontario surgeons to identify gaps in application, and temporal trends of usage. Methods: A prospectively-collected database of provincial insurance billables and diagnostic codes was reviewed retrospectively, from 2002-2014. Patients undergoing instrumented spinal fusions or percutaneous vertebroplasty/kyphoplasty were identified. Fee and diagnostic codes were applied to distinguish surgical indication and approach. The use of intra-operative navigation was determined for each case. Results: We identified 4607 instrumented spinal fusions in our cohort. Most cases were performed by orthopedic surgeons (63.2%) and the remainder by neurosurgeons. Of 2239 cases with identifiable etiology, CAN was utilized in 8.8%, predominantly for trauma and degenerative pathologies rather than deformity. In univariate analyses, CAN was used more often by neurosurgeons (21.0% vs. 12.4%, p<0.001), in academic institutions (15.9% vs. 12.3%, p<0.001), and when performed in/after 2010 (18.9% vs. 8.9%, p<0.001). Differences by specialty and year remained significant in multiple logistic regression. Conclusions: Spinal CAN has proven benefit for instrumentation accuracy, but is used preferentially by academic neurosurgeons. Significant gains must be made in cost and usability to improve access across disciplines and institutions.

Background: Morbidity can be high in the management of adult spinal deformity patients. Complications include blood loss (EBL), durotomy, radicular pain, and postoperative hardware failure. Utilization of one versus two spinal surgeons in spinal deformity correction reduces overall perioperative morbidity is unclear. Methods: All procedures were performed by surgeons at a single institution between January 2012-2015. Patients were followed for a minimum of one year and maximum of four years. We retrospectively reviewed 60 cases of adult spinal deformity. Our cohort was divided into 1 versus 2 surgeons (12 vs 48 cases). We analyzed these cases for estimated blood loss and peri-operative complications. Results: Cases involving long thoracic to pelvis correction (T3-T6) was 20.8% in the 2 surgeons group and 8.3% in the 1 surgeon group. The EBL >3.0 L for 1 versus 2 surgeon groups were 25% and 41.6% respectively. Major complications in the 1 versus 2 surgeon group were 25% and 47.9% and the revision rates were 25% versus 37.5%. The percentage of minor complications in the 1 versus 2 surgeon group was 33.3% versus 14.6%. Conclusions: Utilizing two surgeons did not reduce complication rates. Procedures performed by two surgeons were more extensive deformity corrections. The extent of correction is the likely explanation for differing complication rates.

Background: Instrumentation failure (IF) such proximal junctional kyphosis/failure or distal junctional failure (PJK/PJF/DJF), rod fracture and screw-loosening can cause morbidity in patients with spinal deformity correction. Factors such as bone mineral density (BMD) or region of deformity correction may play a role in postoperative IF. Methods: We reviewed the relationship between IF and BMD or extent of spinal deformity. IF includes PJK/PJF/DJF, fractured rod, screw-looseing, radiculopathy, and non-union. BMD groups included Normal, osteopenia/osteoporosis, and Unknown. The extent of correction included Lumbar, Short Thoracolumbar (5-8 levels), Long Thoracolumbar (8 to 12 levels), and Cervical-thoracic. Results: 60 patients (41:19 F:M) were included, with average age of 65. Total IF=29 patients (48.3%). Normal BMD in N=14, with half of them (50.0%) developing IF; Low BMD in N=15, with one-third of them (33.3%) developing IF. Lumbar correction was performed in N=19, with IF in 36.8%; Short Thoracolumbar correction was performed in N=28, with IF in 46.4%; Long Thoracolumbar correction was performed in N=11, with IF in 81.8%; and Cervical correction in N=2, with no postoperative IF. Conclusions: Patients that received long-segment thoracolumbar had the highest rates of postoperative morbidity. We did not demonstrate an association between abnormal BMD and postoperative IF. A larger study would be needed for further investigations.

Background: Optimal surgical management for flexion--distraction cervical spine injuries remains controversial with anterior, posterior, and circumferential fixation being accepted. Here, we examined risk factors for clinical and radiographic failure in patients with one segment cervical flexion-distraction injuries having undergone anterior surgical fixation. Methods: A retrospective review of 57 consecutive patients undergoing anterior fixation for cervical flexion-distraction injuries between 2008-2012 was performed. The primary outcome was the number of patients requiring additional surgical stabilization and/or radiographic failure. Data collected inlcuded age, gender, mechanism and level of injury, facet pattern injury, and vertebral endplate fracture. Results: Six patients failed clinically and/or radiographically (11%). Four patients (7%) required additional posterior fixation. Two patients identified met radiographic failure criteria, however had fused radiographically, were stable clinically, and no further treatment was pursued. Progressive kyphosis and translation correlated with need for revision (p<0.05 and p=0.02, respectively). No differences were identified for all other clinical and radiological factors assessed. Conclusions: This study supports the growing body of evidence for anterior fixation alone for flexion-distraction injuries. Findings suggest that measurements including segmental translation and kyphosis may predict radiographic failure and need for further surgical stabilization in some patients. Assessment for independent risk factors for anterior approach failure with a validated predictive scoring model should be considered.

Background: Hirayama disease (HD) is characterized by progressive cervical myelopathy caused by repetive neck flexion leading to forward displacement of the posterior dural sack with compression and injury of the spinal cord. Typically, the C7-T1 myotomes become weak and atrophic, while sparing sensation. Here we present two Canadian cases of this rare entity. Methods: Two cases of HD are presented and literature reviewed, showing the diagnostic and therapeutic challenges of this disease. Results: Case 1 is a 17-year-old male professional singer and musician. He presented with bilateral progressive hand weakness, which was aggrevated while playing the violine. Cervical MRI showed increased T2-weighted signaling at C5-7, but a correct diagnosis could not be identified. Eventually, dynamic cervical MRI showed the compression and he underwent an anterior cervical discectomy and fusion (ACDF) at C5-C6 and C6-C7 without complications. Case 2 is a 19-year-old female with progressive right hand weakness. After numerous investigations, a dynamic cervical MRI diagnosed her with HD with classic findings and she underwent an ACDF at C6-C7 without complications. Conclusions: Hiryama’s disease is rare, but should be kept in mind when cervical cord signal changes cannot be explained by standard MRI. Dynamic MRI is imperative to correct diagnosis and anterior fusion shows good outcomes in its management.

Background: Surgery to remove dumbbell nerve sheath tumors (NST) is complex, and is accompanied by significant operative and perioperative challenges. Historically, resection of dumbbell NST required large operations involving opening the chest and laminectomy, often accompanied by instrumentation. We describe a case series of 5 patients who underwent single stage thorascopic-guided resection of dumbbell schwannoma at our institution. Methods: 5 cases presented consisted of moderate to large NST, which contained intraforaminal components. Tumor location ranged from T3-T9, with most tumors spanning 2-3 vertebral bodies. Presentation ranged from discomfort/pain (most common) to one presentation of neurologic deficit with difficulty with ambulation. Results: Thorascopic assisted resection accomplished gross total resection in 4 of the 5 cases. In all cases there was no significant neurologic deficit, although one patient reported transient numbness following the operation and all patients made significant improvement post operatively. The length of stay for these cases ranged from 1-6 days. Conclusions: Thorascopic assisted resection of dumbbell NST can be performed safely and with good outcomes by using the corridor the tumor produces. This approach reduces the need for instrumentation, length of stay and post operative complication rates relative to traditional approaches. To perform this approach effectively, good co-operation between the neurosurgeon and thoracic surgeon needs to be present.

Background: Iatrogenic dural tear a complication of spinal surgery with significant morbidity and cost to the healthcare system. The optimal management is unclear, and therefore we aimed to survey current practices among Canadian practitioners. Methods: A questionnaire was administered to members of the Canadian Neurological Surgeon’s Society designed to explore methods of closure of iatrogenic durotomy. Results: Spinal surgeons were surveyed with a 55% response rate (n=91). For pinhole sized tears there is a trend toward sealant fixation(36.7%). Medium and large sized tears are predominantly closed with sutures and sealant(67% and 80%, respectively). Anterior tears are managed using sealant alone(48%). Posterior tears are treated with a combination of sutures and sealant(73.8%). Nerve root tears are treated with either sealant alone(50%). Most respondents recommended bed rest for at least 24 hours in the setting of medium(73.2%) and large(89.1%) dural tears. Conclusions: This study elucidates the areas of uncertainty with regard to iatrogenic dural tear management. There is disagreement regarding management of anterior and nerve root tears, pin-hole sized tears in any location of the spine, and whether patients should be admitted to hospital or on bed-rest following a pin-hole sized dural tear. There is a need for a robust comparative research study of dural repair strategies.

Background: Two broad categories for the surgical management of symptomatic spondylolysis exist: decompression, or direct reduction and fixation. Direct fixation can maintain mobility and leads to improved outcomes over spinal fusion. The ‘smiley face’ technique is a direct fixation method of pars defect repair that uses one bent rod to reduce the number of linkage points and simplify the construct. Methods: Bilateral pars defects at L3 and L5 were repaired using the ‘smiley face’ technique. Patient reported outcomes, including the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain were assessed preoperatively and again at 6 weeks postoperatively. Results: The patient underwent a soft tissue preserving multi-level bilateral L3 and L5 pars defect repair using the smiley face technique while utilizing radiation-free 3D optical imaging to capture multiple points for registration despite minimal laminar exposure. The patient’s ODI and lower back VAS scores decreased from 25 to 8 and 7.5 to 4 respectively, after surgery, correlating to an excellent outcome on ODI. Conclusions: The smiley face technique can be used with soft tissue preserving techniques to achieve adequate bony reduction while maintaining intersegmental mobility in patients with multi-level pars defects. 3D imaging allows soft tissue preservation with increased registration points for intraoperative navigation.

Background: Current lumbar intervertebral disc prostheses provide suboptimal symptom relief with little natural load-cushioning. PVA-C is a promising biocompatible material, and our previous study finds that it can closely mimic the properties of nucleus pulposus. However, pure PVA-C does not possess adequate stiffness to mimic the annulus fibrosus. Methods: Composite particle-reinforced PVA-C formulations were tested to identify methods that could increase the elastic modulus. This included: sephadex, hydroxyapatite (stock) and hydroxyapatite (in-solution synthesis). All formulations were tested using 15% PVA-C and 5% reinforcing agent. Indentation and durometer tests were performed as well as simple compression, compressive stress relaxation and creep. Results: Indentation and durometer results did not clearly reveal any specific formulations that significantly improved stiffness. The addition of in-solution synthesized hydroxyapatite resulted in 1.15 to 2 time increase in elastic modulus (0.3-0.9 MPa) and associated decrease in stress relaxation and creep. The addition of stock hydroxyapatite and spehadex (G100f and G50sf) lowered the elastic modulus and increased stress relaxation and creep. Conclusions: In-solution synthesized hydroxyapatite is the only particle-reinforced composite PVA-C formulation that exhibited greater stiffness than pure PVA-C. The elastic modulus will need to be increased by 5-10x to adequately mimic the annulus fibrosus. A fiber-reinforced composite will likely be needed to accomplish this.

Background: Current lumbar intervertebral disc prostheses provide suboptimal symptom relief with little natural load-cushioning. PVA-C is a promising biocompatible material, however previous studies from our lab show that it does not have adequate elastic modulus to mimic the annulus fibrosus. Here we present a prototype of an artificial lumbar intervertebral disc. Methods: The tensile properties of pure (5-35% PVA-C) and particle-reinforced (15% PVA-C with 5% of either Sephadex or hydroxyapatite) composite PVA-C formulations were evaluated. Simple tension and tensile stress relaxation tests were performed. Woven Teflon mesh was embedded in PVA-C and tested under compression. Endplate pull-out tests were performed. Results: Tensile testing showed that all PVA-C formulations behaved linearly for physiologic levels of strain (<20%). Tensile elastic modulus is an order of magnitude lower than the annulus fibrosus. Teflon has similar elastic modulus as collagen and compression of the hybrid Teflon-PVA-C construct revealed good biomechanical mimicry with elastic modulus of 20-25MPa at 20% deformation, similar to human data. Bonding between PVA-C and porous titanium endplate is excellent. Conclusions: A fiber-reinforced PVA-C impregnated composite adequately mimics the annulus fibrosus. Our prototype of a tissue mimicking artificial intervertebral disc utilizes a woven Teflon fiber with 20% PVA-C (+Hydroxyapatite) annulus and 5% pure PVA-C nucleus bonded to porous titanium foam endplates.

Background: Pelvic peripheral nerve sheath tumors (PNST), which includes neurofibroma, schwannoma, and MPNST, are rare tumors located in the retroperitoneum. Methods: The case records of a prospectively maintained database at Sunnybrook Health Sciences Center (SHSC) were reviewed to identify patients with pelvic PNST, managed between 2006 - 2016. Medical records were retrospectively reviewed for patient demographics, presentation, tumor location, symptoms, imaging characteristics, management, and outcome. The surgical technical caveats were described. An English language literature review was performed to describe previously published experiences. Results: The series consisted of 7 patients, ranging from 22 - 74 years of age at presentation. These lesions tend to be large at the time of diagnosis, and presenting symptoms include abdominal, flank, or back pain, as well as leg edema or hydronephrosis from local compression. Most patients in this cohort were managed surgically with midline abdominal transperitoneal exposures. Lastly, 5 tumors were benign schwannomas managed with gross total resection or debulking, while 2 patients had MPNSTs managed with biopsy followed by adjuvant chemoradiation therapy. Conclusions: In this case series, we describe the characteristics, evaluation, and management of 7 patients with pelvic PNST at a major healthcare institution in Toronto, Canada, highlighting the technical aspects of managing this rare and challenging entity.

Background: Neurosurgery was first practiced in Victoria, BC in the 1950’s. It has grown from 1 neurosurgeon to 6 neurosurgeons today. Methods: Research into the beginning of Neurosurgery in Victoria demonstrates that it started with one surgeon and has grown significantly over the past 60 plus years. Results: Although Neurosugery started in Victoria with humble beginnings it has now developed into a sophisticated unit with 6 neurosurgeons with various subspeciality interests including complex and minimally invasive spine, cerebrovascular and neuro-oncology. Conclusions: The Neurosurgery division in Victoria has grown over the years from a single surgeon to 6 surgeons practicing a wide scope of neurosurgical procedures.

Background: Previously-identified deficiencies in stroke training for emergency and internal medicine trainees led us to develop a competency-based curriculum for a stroke rotation, based upon entrusbable professional activities (EPAs). EPAs are observable and measurable activities that are routine care within a given medical specialty. Methods: We surveyed stroke- and non-stroke neurologists using a modified Delphi process with two iterations. The survey sought input on the number and nature of EPAs considered most important and achievable during a one month stroke rotation. Results: Surveyed neurologists considered 5-10 EPAs as adequate and reasonable to achieve during a one month elective. A list of the most essential EPAs was obtained and will be used as the basis of a curriculum for rotating residents in Internal and Emergency medicine at the Island Medical Program in Victoria, BC. Conclusions: Our work highlights an approach to meeting an identified gap in resident training in an important area of neurology (stroke). A competency based approach to medical education, focusing on EPAs, offers an innovative way of approaching resident education that seeks to ensure residents develop skills that experts in the field have identified as most essential for the work at hand (in this case, the proper management of stroke patients).

Background: Needs assessment is a cornerstone of designing programs for continuing professional development (CPD). However, typical needs assessment surveys often yield non-specific information insufficient to guide professional development programming decisions. Methods: A survey was distributed to Neurologists practicing in city of Calgary. A stimulated-recall method was used to generate specific case-oriented clinical questions and 5-point Likert scales were used to rate specific topics across the CanMEDS competency framework and CPD preferences. Results: A total of 48 surveys were distributed, with a response rate of 62.5%. Most respondents were subspecialists in Neurology (87%) in practice for less than 15 years (71%). Most used local neuroscience (97%) rounds as source for CPD. Respondents reported a need to address specific questions relating to the following topics: Acute stroke (54%), non-acute stroke (45%) and epilepsy (50%). For example, physicians identified that they wanted to learn more about when to reinitiate anticoagulation following ischemic stroke, or which choice of anti-epileptic for various seizure presentations. Specific medical content was rated highly disproportionately to other physician competencies such as communication or management skills. Conclusions: Our survey elicited detailed learning gaps from academic neurologists and identified a disconnect in interest in topics related to medical content compared to other important physician competencies.

Background: Surgical simulation training offers trainees the opportunity to practice surgical skills before entering the operating room. The objectives of this study were to determine the effect of simulation for learning instruments for burr hole surgery and whether this learning is translated to real instrument recognition with retention. Methods: Randomized trials of PGY1 neurosurgery residents and perioperative nurses were conducted, using PeriopSim™ for instrument recognition, as well as real instruments. Group A performed simulation tasks using PeriopSim™ prior to identifying real instruments, whereas Group B identified real instruments prior to performing simulation tasks. Nurses’ recall was assessed at seven days. Results: Sixteen residents and 100 nurses were recruited. All participants showed significant overall improvement in their scores for simulated tasks. Group A demonstrated enhanced accuracy and speed of identifying real instruments compared with Group B (p<0.001). Furthermore, knowledge recall testing at one week demonstrated retained learning, shown by 97% accuracy in instrument identification. Conclusions: Our results demonstrate that recognition of surgical instruments improves with repeated use of the PeriopSim™ platform. Instrument knowledge acquired through simulation training results in improved identification and retained recognition of real instruments.

Background: Web 2.0 technologies (e.g. blogs, social networks, and wikis) are increasingly being utilized by medical schools and postgraduate training programs as tools for information dissemination. These technologies offer the unique opportunity to track metrics of user engagement and interaction. Here, we employ Web 2.0 technologies to assess academic behaviors among neurosurgery residents. Methods: We performed a retrospective review of all educational lectures, part of the core Neurosurgery Residency curriculum at the University of Toronto, posted on our teaching blog (www.TheBrainSchool.net) from Sept 2013 - Nov 2016. We looked for associations with lecturer’s academic position, timing of examinations, and lecture/subspecialty topic. Results: The overall number of clicks on 123 lectures was 1079. Most of these clicks were occurring during the in-training exam month (43%). Click numbers were significantly higher on lectures presented by faculty (mean 18.6, SD ± 4.1) compared to residents-delivered lectures (mean 8.4, SD ± 2.1) (P= 0.031). Functional neurosurgery lectures were the most downloaded (47%), followed by pediatric neurosurgery (22%). Conclusions: The current study demonstrates the value of Web 2.0 analytic tools in examining residents study behavior. Residents tend to ‘cram’ downloading lectures in the same month of training exams and display a preference for faculty-delivered lectures.

Background: Residency training programs aspire to develop residents’ research skills, but engaging trainees in research often proves challenging. Addressing this requires a better understanding of factors influencing residents’ engagement in scholarship. We sought to identify such factors through an interview-based study that explored residents’ interest and involvement in research during training. Methods: We conducted 15 semi-structured interviews with neurology (n=8) and neurosurgery (n=7) residents at our institution based on an interview guide developed through a literature review and pilot interviews (n=3). Using template analysis, we examined transcripts to identify facilitators and barriers to resident research. Results: Motivation, mentorship, and resource availability were noted to significantly impact resident research. Trainees indicated motivation is influenced by personal desire to develop research skills, interest in available projects, and pressure to engage in scholarship from peers, mentors, and future employers. While strong mentorship and departmental resources for data collection and analysis facilitate resident research, funding and time constraints are barriers to success. Conclusions: We have identified multiple factors influencing residents’ engagement in research, which may be targeted by program directors to optimize the post-graduate training environment for resident scholarship. In the next phase of our project, we will corroborate and expand on these findings through a national survey of residents across all specialties.