bluuebunny/crossref_metadata_2025 huggingface dataset:
Does the Alpha-defensin Immunoassay or the Lateral Flow Test Have Better Diagnostic Value for Periprosthetic Joint Infection? A Systematic Review
Authors: Eriksson Hannah K. , Nordström Jakob , Gabrysch Katja , Hailer Nils P. , Lazarinis Stergios
Published: June 2018

Background

Measuring alpha-defensin concentrations in synovial fluid may help to diagnose periprosthetic joint infection (PJI). There are two commercially available methods for measuring alpha-defensin in synovial fluid: the enzyme-linked immunosorbent assay-based Synovasure® alpha-defensin immunoassay, which gives a numeric readout within 24 hours, and the Synovasure lateral flow test, which gives a binary readout within 20 minutes. There is no compilation of the existing literature to support the use of one of these two tests over the other.

Questions/purposes

Does the immunoassay or the lateral flow test have better diagnostic value (sensitivity and specificity) in diagnosing PJI?

Methods

We followed PRISMA guidelines and identified all studies on alpha-defensin concentration in synovial fluid as a PJI diagnostic marker, indexed to April 14, 2017, in PubMed, JSTOR, Google Scholar, and OVID databases. The search retrieved 1578 records. All prospective and retrospective studies on alpha-defensin as a PJI marker (PJI classified according to the criteria of the Musculoskeletal Infection Society) after THA or TKA were included in the analysis. All studies used only one of the two commercially available test methods, but none of them was comparative. After excluding studies with overlapping patient populations, four studies investigating the alpha-defensin immunoassay and three investigating the lateral flow test remained. Alpha-defensin immunoassay studies included 482 joints and lateral flow test studies included 119. The quality of the trials was assessed according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The heterogeneity among studies was evaluated by the I2 index, indicating that the heterogeneity of the included studies was low. Pooled sensitivity, specificity, positive and negative likelihood ratios, and receiver operating curves were calculated for each method and compared with each other.

Results

The alpha-defensin immunoassay had superior overall diagnostic value compared with the lateral flow test (area under the curve, 0.98 versus 0.75) with higher sensitivity (96% [90%-98%] versus 71% [55%-83%], p < 0.001), but no difference in specificity with the numbers available (96% [93%-97%] versus 90% [81%-95%], p = 0.060).

Conclusions

Measurement of alpha-defensin in synovial fluid is a valuable complement to existing diagnostic criteria, and the immunoassay test detects PJI more accurately than the lateral flow test. The lateral flow test has lower sensitivity, making it difficult to rule out infection, but its relatively high specificity combined with the advantage of a quick response time can make it useful to rule in infection perioperatively.

Level of Evidence

Level III, diagnostic study.
P.002 Exosomal miR-204-5 and miR-632 in CSF are candidate biomarkers for frontotemporal dementia: a GENFI study
Authors: Schneider R , McKeever P , Kim T , Graff C , van Swieten J , Karydas A , Boxer A , Rosen H , Miller B , Laforce R , Galimberti D , Masellis M , Borroni B , Zhang Z , Zinman L , Rohrer JD , Tartaglia MC , Robertson J
Published: June 2018

Background: To determine whether exosomal microRNAs (miRNAs) in CSF of patients with FTD can serve as diagnostic biomarkers, we assessed miRNA expression in the Genetic FTD Initiative (GENFI) cohort and in sporadic FTD. Methods: GENFI participants were either carriers of a pathogenic mutation or at risk of carrying a mutation because a first-degree relative was a symptomatic mutation carrier. Exosomes were isolated from CSF of 23 -pre-symptomatic and 15 symptomatic mutation carriers, and 11 healthy non-mutation carriers. Expression of miRNAs was measured using qPCR arrays. MiRNAs differentially expressed in symptomatic compared to pre-symptomatic mutation carriers were evaluated in 17 patients with sporadic FTD, 13 patients with sporadic Alzheimer’s disease (AD), and 10 healthy controls (HCs). Results: In the GENFI cohort, miR-204-5p and miR-632 were significantly decreased in symptomatic compared to pre-symptomatic mutation carriers. Decrease of miR-204-5p and miR-632 revealed receiver operator characteristics with an area of 0.89 [90% CI: 0.79-0.98] and 0.81 [90% CI: 0.68-0.93], and when combined an area of 0.93 [90% CI: 0.87-0.99]. In sporadic FTD, only miR-632 was significantly decreased compared to sporadic AD and HCs. Decrease of miR-632 revealed an area of 0.89 [90% CI: 0.80-0.98]. Conclusions: Exosomal miR-204-5p and miR-632 have potential as diagnostic biomarkers for genetic FTD and miR-632 also for sporadic FTD.
P.007 Familial idiopathic normal pressure hydrocephalus in a Canadian family
Authors: Shettar BC , Mirsattari S
Published: June 2018

Background: Idiopathic Normal-pressure hydrocephalus (iNPH) is characterized by cognitive impairment, gait disturbance, enlarged ventricles with/without cerebral atrophy, with/without urinary incontinence, and normal cerebrospinal fluid pressure. Familial iNPH is very rarely described in the literature. A Canadian family with more than one generation of iNPH has never been described. Methods: Patient 1: 50-year-old female presented with wide-based and magnetic gait, multiple falls with subsequent freezing. LP with large volume tap was performed. Patient had ventriculo peritoneal (VP) shunt surgery. Patient 2: 52 year male (brother): Presented with long-standing cognitive impairment and fatigue. Montreal Cognitive Assessment (MOCA) was performed. Whole exome sequencing(WES) of both siblings as well as an unaffected first cousin was done. The father and grandmother of both patients was diagnosed with iNPH. Results: Patient 1: Opening pressure on LP was 22 cm-H2O. She responded well to large volume tap. She had VP shunt resulting in improved gait. Patient 2: Opening pressure on LP was 16cm-H2O. CSF flow study was slow for age indicative of NPH. MoCA score was 25/30. WES of patients and unaffected first cousin is underway. Conclusions: We present an undescribed Canadian family with iNPH in more than one generation. WES is underway for better understanding of genetic predesposition and inheritance of familial iNPH
P.012 Post-operative hippocampal volume changes on magnetic resonance volumetry in patients with mesial temporal lobe epilepsy
Authors: Iida K , Katayama J , Kagawa K , Katagiri M , Seyama G , Hashizume A , Kurisu K , Otsubo H
Published: June 2018

Background: We evaluate long-term post-operative hippocampal volume (HV) on non-epileptic hippocampus using MR volumetry as well as the neuropsychological outcome in patients with surgery for unilateral mesial temporal lobe epilepsy (MTLE) and achieved seizure-freedom. Methods: We studied 1.5-Tesla MRI before and after epilepsy surgery in 24 patients with MTLE. Serial MRI studies were scheduled at 4 post-operative consecutive periods; 6m-1y; 1-2y; 2-3y; 3-5y. We compared neuropsychological outcomes for memory and estimated IQ at the same periods with serial MRI up to 3 years. Results: The pre-operative non-epileptic HV was significantly smaller than HV in age-matched controls (n=14) (p<0.05). The HV became progressively atrophic after the surgery (p<0.05), correlating with the age at surgery (p<0.05) and pre-operative larger non-epileptic HV (p<0.05), but not with seizure duration. In 14 patients with non-dominant MTLE, the smaller dominant HV at 2-3y period correlated with decline of verbal memory (p<0.05). Conclusions: Post-operative progression of non-epileptic hippocampal atrophy was found with significantly more pronounce in patients with older age at surgery and larger pre-operative non-epileptic hippocampus. After the epileptogenic hippocampus is resected, the remaining hippocampus alone might exhaust to maintain the memory, especially in elders.
P.018 Forced normalization after vagal nerve stimulation in a case of intractable Lennox-Gastaut syndrome
Authors: Denton A , Vitali A , Waterhouse K , Tellez-Zenteno J
Published: June 2018

Background: Forced normalization is the development of psychiatric symptoms in a patient experiencing remission of intractable seizures. The mechanism of this phenomenon is unknown. We present a complex case of Lennox Gastaut syndrome that experiences forced normalization after vagus nerve stimulation (VNS). Methods: This case details a 31-year-old male with seizures since early childhood. The patient has intractable epilepsy and failed AEDs, VNS, and a partial callosotomy. Results: The patient was in remission from 2-12 years old, when seizures returned at a frequency of 2-5 per day. He has multiple types of seizures including drop attacks, absences, and tonic-clonic seizures. Patient experienced status epilepticus multiple times. Twelve AEDs were failed before VNS was started in 2010, which helped curb the severity of seizures and the potential for clusters. Forced normalization developed over the course of treatment with VNS. The patient behavior was characterized by aggression, paranoia, and hallucinations. VNS was turned off late in 2010 and then re-started in January of 2011. Patient proceeded to cycle between several days of seizures without psychiatric symptoms and several days of psychosis without seizures. Conclusions: Vagus nerve stimulation gave way to forced normalization, characterized here as aggressive behaviour and psychosis. Forced normalization is seen commonly after epilepsy surgery, but rarely following VNS.
P.024 Educational needs in migraine care: results from a mixed-methods study among Canadian primary care providers and specialists
Authors: Peloquin S , Leroux E , Shapero G , Labbe S , Murray S , Dodick DW , Becker W
Published: June 2018

Background: Migraines are sub-optimally treated, affect millions of Canadians, and are underrepresented in medical training. A study was conducted to identify the needs of Canadian Healthcare Providers (HCPs) for migraine education, with the aim to inform the development of learning activities. Methods: This ethics-approved study was deployed in two consecutive phases using a mixed-methods approach. Phase 1 (qualitative) explored the causes of challenges to migraine care via a literature review, input from an expert working group, and semi-structured interviews with multiple stakeholders. Phase 2 (quantitative) validated these causes using an online survey. Results: The study included 103 participants (28 in phase 1; 75 in phase 2): general practitioners=37; neurologists=24; nurses=14; pharmacists=20; administrators, policy influencers and payers=8. Four areas of sub-optimal knowledge were identified: (1) Canadian guidelines, (2) diagnostic criteria, (3) preventive treatment, and (4) non-pharmacological therapies. Attitudinal issues related to the management of migraine patients were also identified. Detailed data including the frequencies of knowledge gaps among general practitioners and general neurologists will be presented along with qualitative findings. Conclusions: Educational activities for general practitioners and general neurologists who treat patients with migraines should be designed to address the four educational needs described in this study.
P.030 Clinical findings, immunotherapy and neuroimaging results in Pediatric Anti-NMDA Receptor Encephalitis
Authors: Ogilvie R , Morneau-Jacob F
Published: June 2018

Background: Anti-NMDAR Encephalitis is an autoimmune disease of children and adults which most often presents with sub-acute psychiatric disturbance or seizures, but includes a broad group of potential clinical manifestations. Routine neuroimaging, such as cerebral MRI, is often nonspecific or normal. Methods: This study reports a series of retrospectively reviewed pediatric patients with AntiNMDAR encephalitis with emphasis on the evolution of clinical features over time, cerebral MRI, 18-FDG Positron emission tomography (PET) findings, and post illness neurocognitive features. Results: Four cases of Antibody confirmed AntiNMDAR encephalitis were included, two male and two female, of a mean of 13 years of age. Patients had a mean of three symptom categories by presentation, though many of these were subtle, progressing to 6.5 by the end of the first month. MRI, CSF and EEG were abnormal for one, three and all patients, respectively. All patients had abnormal cerebral PET scans, and all displayed some temporal lobe hypermetabolism on either initial or repeat cerebral PET Scan. Conclusions: Anti-NMDAR encephalitis is a variable disorder with an evolving clinical presentation in children. Temporal hypermetabolism on cerebral PET may be a time dependent feature of the disorder.
P.049 Repeat surgery in recurrent glioblastoma: a systematic review and meta-analysis
Authors: Wang JZ , Nassiri F , Badhiwala JH , Zadeh G
Published: June 2018

Background: Recurrent glioblastoma portends a poor prognosis and the role of repeat surgery in improving survival remains uncertain. Our systematic review and meta-analysis aims to address whether re-resection provides a meaningful survival benefit and to what degree. Methods: Articles were collected from Pubmed, -CINAHL, EMBASE, Medline and Cochrane from January 1990 to 2018. Studies in the temozolomide era with both single surgery and re-resection cohorts were included. Primary outcomes were odds ratio for survival at 6, 12, and 24 months following re-resection and initial surgery. Results: Fourteen articles were included for analysis (3048 patients). Meta-analysis showed improved overall survival following re-resection at 6- (OR 1.73, 95% CI 1.23-2.45, p<0.05), 12- (OR 1.71, 95% CI 1.20-2.45, p<0.05), and 24-months (OR 2.24, 95% CI 1.01-4.95, p<0.05). Overall survival from diagnosis or first surgery was also improved in patients who underwent re-resection at -recurrence, similarly at 6- (OR 8.22, 95% CI 5.23-12.93, p<0.01), 12- (OR 4.16, 95% CI 3.25-5.36, p<0.01), and 24- (2.35, 95% CI 1.77-3.11, p<0.05) months. Subgroup analyses were done for patients stratified by age, performance status, and number of re-resections. Conclusions: Repeat surgery for recurrent glioblastoma is associated with a significant survival advantage independent of other salvage therapies that include chemotherapy, radiation, and other antineoplastic regimens.
P.060 Utility analysis of continuous video EEG (cvEEG) monitoring during the treatment of hypoxic ischemic encephalopathy (HIE) in the NICU
Authors: Braun MH , Bello-Espinosa L , Appendino J , Buchhalter J , Mohammad K , Esser M
Published: June 2018

Background: Therapeutic hypothermia (TH) improves the outcome in HIE but cvEEG is vital to detect any seizures that occur. Unfortunately, the costs associated with cvEEG can make it impractical. We studied outcomes in TH with the objective of optimizing the length of cvEEG required. Methods: Term infants with HIE were treated with 72 h of TH followed by 6 h of rewarming. cvEEG reports were quantified (background, sharp transients, seizures) and compared with pre and post-cooling variables to determine whether risk stratification was possible. Results: 25/78 infants had seizures during the TH, however, most seizures occurred early, with 7 infants seizing prior to cooling and 15 having their first seizure within 24h. Only 3 infants had their first seizure between 24-48h and none were recorded after. Novel seizures after 24h were brief and did not require treatment. EEG variables such as frequent sharp transients and first seizures within 24h were correlated with MRI abnormalities. Conclusions: For the majority of infants undergoing TH, 24h of cvEEG may be sufficient with few infants requiring longer than 48h. A combination of clinical variables (abnormal neurological exam) and EEG traits (frequency of discharges, seizures) can help to decide on the likelihood of seizures and length of EEG recording needed.
P.073 Cardiac dysfunction in mitochondrial disease: systematic review and metaanalysis
Authors: Quadir A , Pontifex CS , Robertson H , Labos C , Pfeffer G
Published: June 2018

Background: Cardiac dysfunction has significant impact on morbidity and mortality in patients with mitochondrial disorders. Cardiac screening tests are generally recommended because cardiac dysfunction can occur at any point in the disease course, and is amenable to treatment. However there is no clear evidence indicating the best screening strategy in patients with mitochondrial myopathy. Methods: Systematic review of the literature for cardiac investigations in adult patients with mitochondrial myopathy. We considered 1303 relevant abstracts, from which 58 full-length articles were reviewed. Seventeen articles including 701 total participants met inclusion criteria. Data extracted included age, diagnosis, and results from ECG, echocardiogram, cardiac MRI, nuclear medicine studies, and Holter monitor. Results: We identified echocardiogram and ECG as the principal screening modalities, that identify cardiac structural (26%) and conduction abnormalities (37%) in patients from various mitochondrial myopathy syndromes. Holter monitor was not a high yield investigation and limited studies were identified using cardiac MRI or nuclear medicine. Conclusions: We recommend screening with ECG and echocardiogram every 1-2 years in MERRF/MELAS, and every 3-5 years in milder syndromes when cardiac symptoms are not present. Only five of the included studies provided any follow-up data. We recommend studies of natural history, therapeutic response, and of cardiac MRI as areas for future study.
P.077 Utility of a next generation sequencing in the diagnosis of Congenital Myasthenic Syndromes
Authors: Zapata-Aldana E , Nguyen CE , Nicolle MW , Carere DA , Stuart A , Campbell C , Sadikovic B
Published: June 2018

Background: Congenital Myasthenic Syndromes (CMS) are heterogeneous disorders caused by genetically determined structural or functional differences in proteins involved with the neuromuscular junctions. Clinical and molecular genetics studies of CMS patients have revealed significant locus heterogeneity; there are 21 known genes related to CMS, but other genes may mimic the phenotype, justifying the use of a multi-gene panel for genetic testing Methods: Our group developed custom sequence capture probes designed to flank 27 different genes associated with CMS, including enrichment for all coding exons as well the flanking intronic regions. We enrolled 20 patients from the paediatric and adult neuromuscular clinic with a clinical phenotype of CMS. Using custom analytical, we -assessed the sequence variants and exon-level CNVs for each patient. Results: Thirteen male and seven female patients with median age of 12.25 years (range 1.5-39y) were assessed. We identified missense and CNVs in 17 patients, including established pathogenic mutations confirming the diagnosis in 5 patients Conclusions: The use of Next Generation Sequence with CNV for CMS can help determine the underlying causes of most CMS disorders and allow appropriate medical treatment, refined genetic counseling, and improved understanding of prognosis, justifying the implementation in the standard clinical screening of CMS.
P.083 Effective video technology for teaching the neurological exam
Authors: Lee S , Yuen Y , Shi G , Calvin C , Liu J , Soh V , Rothman Z , Henri-Bhargava A
Published: June 2018

Background: With advancements in technology, the use of video as a pedagogical method in medical education has gained in popularity, and may aid in teaching clinical skills. In the UBC MD program, videos have been used to assist in teaching the -neurological exam for several decades, but the currently available videos are outdated and not of contemporary quality. Methods: Drawing upon the cognitive theory of multimedia learning from Mayer and Moreno (2003) which describes methods to maximize learning by minimizing cognitive load, we developed a tool to systematically assess pedagogical videos. We inventoried twelve existing neurology videos and analyzed their use of methods such as weeding (removing extraneous information), signalling (visually highlighting important information), and chunking (grouping similar information together). Results: Generally, older videos had poor audiovisual quality that introduced extraneous load, while more current videos had higher production value, albeit inconsistent with the depth of their content. We therefore produced a new three-part neurological exam video series. We wrote storyboards, filmed with a focus on visually depicting the exam and findings, and edited to elucidate relevant physiological concepts. Conclusions: The end product has been adopted by the UBC MD program, and can be shared with other programs who may wish to adopt them.
P.085 Hot seat concept in neurosurgical exam simulation adopted by the Comprehensive Clinical Neurosurgery Review
Authors: Alshafai Ns , Alduais W
Published: June 2018

Background: Neurosurgical education is one of the most exciting topics in contemporary neurosurgery. Passing the final boards is a real challenge. Methods: We conducted a prospective study of 48 candidates who attended the hot-seat sessions during CCN review over three years. Detailed statistical analysis was conducted. Those who attended the Hot seats (Group 1) and those who didn’t (Group 2). The neurosurgery exam simulation was conducted using both MCQ and Oral simulated exams with clinical cases led by world expert faculty in a lecture format for the MCQ and 15-minute mock oral sessions which was video-taped scoring candidates in a standardized fashion for their performance. Results: Group 1 had a better MCQ performance (83 %) compared to group 2 (61 %). Candidates were better in data gathering, differential diagnosis and management. They were worst in simulating surgical techniques and follow-up plans. Geographical characterization showed a big range of intra and inter variability in performances. Interestingly, candidates with excellent MCQ performance had moderate hot seat performance while those with moderate MCQ performance did much better during the hot seat session. Conclusions: Our preliminary results showed that simulation of board exams is a method that will help neurosurgery residents not only pass their board exams, but also achieve the best marks.
P.087 “Reported Brain Injury” Time trends within two Canadian health surveys over two decades
Authors: Gordon KE , Kuhle S
Published: June 2018

Background: An “epidemic” of concussions has been widely reported. We explored the annual incidence of reported concussion or other brain injury, over 20 years within Canada in order to explore the magnitude of this reported epidemic. Methods: Two Canadian nationally representative health surveys have serially collected injury data associated with disability. The National Population Health Survey (NPHS) (1994-9) collected data on “concussion”, and the Canadian Community Health Survey (CCHS) (2000-current) has collected data on “concussion or other brain injury”. Data on respondents 12 years and older reporting concussion with or without other brain injury within the past year were examined in order to produce serial incidence data. Results: Nationally representative data were available biennially from 1994/95 through 2013/14 with the exception of 2007/08 and 2011/12. The incidence of reported concussions, or concussions and other brain injury has been stable until 2005/06 when the reported annual incidence started an upward slope to levels 250% higher (p<0.001) without any apparent stabilization by 2013/14, when approximately 1 in 200 Canadians 12 years and older report concussion or other brain injury as their most significant injury associated with disability in the previous 12 months. Conclusions: There is currently a pandemic of reported brain injury in Canada.
P.088 Antithrombotic agents and traumatic brain injury in the elderly population: hemorrhage patterns and outcomes
Authors: Scotti P , Troquet J , Seguin C , Lo B , Marcoux J
Published: June 2018

Background: In the elderly population, use of antithrombotic therapy (AT), antiplatelets (AP – aspirin, clopidogrel) and/or anticoagulants (AC – warfarin, DoAC – Dabigatran, Rivaroxaban, Apixaban), to prevent thrombo-embolic events must be carefully weighed against the risk of intracranial hemorrhage (ICH) with trauma. We hypothesize that for all patients 65yro+ with head trauma, those on AT will be more likely to sustain a traumatic brain injury, ICH, and poorer outcomes. Methods: Data was collected from all head trauma patients 65yo+ presenting to our tertiary trauma center (level 1) over a 24-month period; age, gender, injury mechanism, medications, International Normalized Ratio, reversal therapy, Glasgow Coma Scale (GCS), ICH, surgery, Extended Glasgow Outcome Scale score (GOSE) and mortality. Results: 1365 patients were identified; 724 on AT (413 AP, 151 AC, 59 DoAC, 48 2AP, 38 AP+AC, 15 AP+DoAC) and 474 not (non-AT). When adjusted for covariates, AT patients were more likely to have ICH (p=0.0004), more invasive surgical interventions (p=0.0188), functional dependency (GOSE≤4; p<0.0001) and mortality (p<0.0001). Risk of mortality is notably high with 2AP (OR 5.74; p=0.0003) and AC+AP (OR 4.12; p=0.0118). Conclusions: Elderly trauma patients on AT, especially combination therapy, have higher risks of ICH and poorer outcomes compared to those who are not.
P.091 Small unruptured intracranial aneurysms: the natural history in Saskatchewan
Authors: Mann J , Ahmed U , Kelly M , Peeling L , Meguro K
Published: June 2018

Background: The natural history of small unruptured intracranial aneurysms (UIAs) <7mm is 0 to 1.3% per year. Our centre provides cerebrovascular care for the entire province allowing for long-term follow-up. We studied the safety of observation for aneurysms <7mm. Methods: We performed a retrospective chart review of patients with intracranial aneurysm referred to our centre between July 2008 and April 2015. Aneurysm characteristics and current status (followed, treated, not followed), were collected along with patient factors. Follow-up duration for each aneurysm was used to calculate total follow-up in aneurysm-years. Statistical evaluation consisted of multivariate analysis and logistic regression analysis. Results: 428 patients harbouring 497 aneurysms <7mm were identified. 67 presented with rupture. Of the remaining 430 aneurysms, there was a 9.3% treatment rate. 2 cases of rupture occurred in those patients who were followed, creating a 0.5% rupture rate. 325 aneurysms were followed for 631.3 total cumulative aneurysm-years, an average of 1.9 aneurysm-years. Smoking status and hypertension associated with presence of aneurysm (p≈0.009,0.026, respectively). Conclusions: In our selected patient group there is a low yearly rate of aneurysm rupture, and observation of aneurysms <7mm is safe. Hypertension and smoking were associated with the development of aneurysm. 9.3% of patients were treated, likely leading to a reduced natural history risk.
P.092 Eagles and Talons: A case of cervical artery dissection from Eagle syndrome and fibromuscular dysplasia
Authors: Wasyliw S , Hunter G
Published: June 2018

Background: Eagle syndrome (also known as stylohyoid syndrome) and fibromuscular dysplasia (FMD) are rare conditions that have both been shown to be associated with cervical artery dissections (CAD). Direct mechanical injury from a neighboring bony fragement can produce arterial dissections and is the proposed mechanism in Eagle syndrome. The etiology of FMD remains unclear, however, similar shearing stresses have been proposed. We present a case in which both of these conditions were present. Methods: Case report Results: A previously healthy 52 year old male presented with an acute left MCA syndrome with computer tomography angiography followed by convensional angiography confirming a complete occlusion of the left ICA at the carotid bifurcation with evidence of a dissection of the proximal cervical carotid artery. Luminal irregularities proximal to the dissection and also of the right ICA were in keeping with fibromuscular dysplasia. A carotid stent was placed and a thrombectomy was performed for a proximal left M2 occlusion. On further review of the CT, the patient had markedly elongated styloid processes bilaterally, meeting criteria for Eagle syndrome. Conclusions: Previous literature has not described these two conditions coexisiting. We question whether chronic mechanical stress from an elongated styloid process could lead to arteries having an irregular or beading appearance resembling fibromuscular dysplasia.
P.094 Characterizing post-stroke autonomic functioning. sub-study protocol of the clinical arm of PARADISE study
Authors: Alsubaie RS , Paquet M , Paturel J , Fridman S , Kimpinski K , Sposato LA
Published: June 2018

Background: Strokes can cause a variety of cardiovascular complications. The underlying mechanisms are largely unknown but there is evidence that dysautonomia plays a role in stroke induced-heart injury (SIHI) and arrhythmias triggered by damage of specific brain regions involved in the autonomic regulation of cardiac functions. Understanding these mechanisms could aid in preventing these cardiovascular consequences. We hypothesize that compared to -patients with sinus rhythm (SR) or with cardiogenic atrial fibrillation known before the stroke (cKAF) or diagnosed after the stroke (cAFDAS), those with neurogenic AFDAS (nAFDAS) will show a specific pattern of autonomic functioning. Methods: We will prospectively evaluate 200 ischemic stroke patients at the London Health Sciences Center University Hospital. Participants will undergo continuous electrocardiographic monitoring during 14 days. Based on pre-specified criteria, patients with AFDAS will be classified into presumably neurogenic vs cardiogenic. We will assess autonomic function within 14 days after stroke onset by using the Autonomic Reflex Screening. We will compare markers of cardiac dysfunction with autonomic changes, as well as specific stroke topographies for SR, cKAF, cAFDAS, and nAFDAS. Results: We are currently performing an interim analysis. Conclusions: Characterizing the autonomic changes that occur after ischemic stroke and their relationship with heart injury will help to advance knowledge on the pathophysiology of SIHI.
P.099 Specialty centres for MVD surgery
Authors: Montazeripouragha A , Kaufmann AM
Published: June 2018

Background: The aim of this study is comparing the waiting time and patient’s satisfaction of microvascular decompression (MVD) surgery between local Manitoba (MB) and out of province (OOP) patients, treated at our Centre for Cranial Nerve Disorder (CCND). Methods: Data from 100 consecutive patients (average age: 56.8±10.6 years), undergoing MVD surgery for Trigeminal Neuralgia (TN) and Hemifacial Spasm (HFS) were reviewed. The outcome measures included the time intervals between disease onset, diagnosis and referral to CCND, postoperative discharge, satisfaction with surgical outcome and referral process. Results: The preoperative time leading to CCND referral were longer for OOP patients, (onset to diagnosis/diagnosis to referral: 2.6±3.8/4.2±4.7 (OOP) versus 1.2±2.1/2.5±4.1 (MB) years; p=0.04/0.04), and referrals were more likely self-directed in OOP patients (62% (OOP), 21% (MB); p=0.007). Postoperative satisfaction with MVD outcome were 8.6/10 for OOP and 8.3/10 for MB patients. There was no significant difference in postoperative length of stay (38±50 (OOP)/43±42 (MB) hours); however, OOP patients were more likely discharged on the first postoperative day (58% (OOP), 31% (MB); p=0.17). Conclusions: Delays in diagnosis and surgical referral of TN/HFS are common, and many patients seek specialist’s opinion in high volume surgical centers. For those OOP patients, travelling for treatment, MVD outcome were at least as good as for local patients.
P.101 Lateral medullary syndrome due to left vertebral artery occlusion in a boy post flexion neck injury
Authors: Alawadhi A , Saint-Martin C , Sebire G , Shevell M
Published: June 2018

Background: Wallenberg’s syndrome (WS), or lateral medullary syndrome is rare in pediatrics, but is not uncommon in adults. It is characterized by neurological deficits due to an ischemic lesion in the lateral medulla. Methods: Case report Results: We describe a 17-year-old boy who developed WS in the context of hyperflexion injury to the neck while diving in shallow water with vertebral dissection as a presumed etiology. He had ‘crossed’ neurological deficits above and below the neck. His MRA showed intra and extracranial left vertebral artery occlusion and his MRI showed T2W/FLAIR signal abnormality involving the left lateral medulla and inferomedial aspect of the cerebellum in keeping with infarcts secondary to the left vertebral artery thrombosis and occlusion of the left posterior inferior cerebellar artery. He was started on anti-coagulation after spinal surgery. On discharge, he had persistent dysphagia which prompt a gastrostomy tube placement prior to transfer to a rehabilitation center. Conclusions: Our case demonstrates that WS can occur post flexion injury in the pediatric population. The presence of crossed neurological findings above and below the neck in the context of neck injury is an important diagnostic clue that should prompt imaging study focusing on the brain stem and the posterior fossa vascular structures.
P.104 Peri-cavity atrophy after minimally invasive evacuation of intracerebral hemorrhage
Authors: Ahmed S , Scaggiante J , Mocco J , Kellner C
Published: June 2018

Background: Intracerebral hemorrhage (ICH) remains a significant cause of morbidity and mortality. While traditional surgical techniques have shown marginal clinical benefit of ICH evacuation, minimally invasive techniques have shown some promise. Endoscopic evacuation of the hemorrhage may reduce the peri-hematoma edema and subsequent atrophy around the hemorrhage cavity. This study aims to quantify the changes in cavity volume following hematoma evacuation. Methods: Patients from the INVEST registry of minimally invasive ICH evacuation were included retrospectively if follow-up computed tomography (CT) scans were available for analysis. Hematoma cavity volumes were calculated from the immediate post-procedural and three-month follow-up CT scans using the Analyze Pro software. Results: Twenty patients had follow-up CT scans at a mean time of 93 days from hematoma evacuation. The average cavity size at follow-up was 11938.12 mm3 (SD: 6996.49). The change in cavity size compared to the prior CT was 6396.74 mm3 (median 2542; range: -1030-27543; SD: 8472.45). This represented mean growth in cavity volume of 54%. Conclusions: This study provides preliminary data describing increase in cavity size after endoscopic minimally invasive evacuation of ICH. Comparison to atrophy in conservatively-managed patients is a further planned avenue of research.
P.107 Acute thrombectomy in patients of 80 years and older: a retrospective analysis of radiological and clinical outcomes with an intention to treat analysis
Authors: Cora EA , Demetriou V , Essbaiheen F , Alqahtani H , Drake B , Lesiuk H , White P , Iancu D
Published: June 2018

Background: The safety and clinical outcomes of thrombectomy in the 80 years or older age group are not yet clear. Our aim is to provide data from clinical practice to assess the safety and efficacy of endovascular thrombectomy in this age group. Methods: We retrospectively reviewed consecutive patients of age ≥80 referred for thrombectomy procedures at our institutions from 01/01/2015 to 01/09/2015. We collected demographic data, risk factors, clinical and radiological findings, treatment details, clinical and radiological outcomes. Results: Data for 75 patients was included. Baseline clinical characteristics are similar to previous trials. There were MCA occlusions in 49% (37/75) and tandem occlusions in 15% (11/75) patients. 67% (50/75) patients received IVtPA. Good reperfusion (mTICI 2b/3) was achieved in 60% (45/75) patients within 224 minutes. Good clinical outcome (mRS 0-2) at 90 days was achieved in 31% (23/75) patients. Results are similar to HERMES data on patients of age ≥80 and differences will be discussed. Conclusions: Our study adds valuable evidence to the limited data on safety and clinical outcomes in patients 80 years of age and older who undergo thrombectomy. Our findings support the data from clinical trials and confirm that mechanical thrombectomy can be performed safely and in a timely fashion outside of trials with similar results.
P.112 Hospital readmission following neurology discharge: A systematic review
Authors: Burke G , Jewett GA , Peters S
Published: June 2018

Background: Unplanned hospital readmission is inconvenient for patients, puts them at risk of harm, and is a resource strain. We reviewed available literature on risk factors for readmission following discharge specifically from neurology inpatient services with a focus on factors unique to non-stroke neurology admissions. Methods: We conducted a systematic search using PRISMA methodology of MEDLINE, EMBASE, and CENTRAL databases up to January 1, 2018. Two independent reviewers screened articles for inclusion. English-language articles were included that identified factors related to hospital readmission after discharge from a neurology service. Admissions with stroke as the primary focus were excluded. Results: Of 9508 unique abstracts, 25 met inclusion criteria and were included for review. Multiple factors impacting probability of readmission were identified including age, living alone, history of nonepileptic seizure, length of stay, services consulted during hospital stay, hospital volume, and severity of illness. Conclusions: There are identifiable risk factors that influence likelihood of readmission to hospital following discharge from neurology inpatient services, although the non-stroke literature is sparse. There is a need for future prospective work to investigate modifiable risk factors and opportunities to reduce readmission rates and improve patient safety.
P.118 Trigemino-cardiac reflex: a case report of intra-operative asystole in response to manipulation of the temporalis muscle
Authors: Shakil H , Wang A , Reddy K
Published: June 2018

Background: The trigemino-cardiac reflex (TCR) is a sudden onset of bradycardia, hypotension, apnea or gastric hypermotility during stimulation of the trigeminal nerve. Methods: We conducted a MEDLINE search for surgical cases of TCR and herein describe a case seen recently at our institution. Results: A 60 year-old female underwent a left orbitozygomatic craniotomy for resection of a skull-base tumor. Pre-operative anesthesia evaluation was unremarkable and negative for a history of cardiovascular disease. Intra-operatively, retraction with moderate force of the temporalis muscle consistently produced asystole. Cessation of retraction resulted in immediate return of sinus rhythm. Otherwise, intra-operative heart rate was 60-90 BPM. Post-operatively, vital signs and clinical course were unremarkable. The patient experienced a similar phenomenon during an operation 6 years earlier, when manipulation of tumor near cranial nerves IX/X resulted in bradycardia. TCR is the result of a polysynaptic brainstem network involving the afferent trigeminal sensory nucleus, the reticular formation, and the efferent vagal motor nucleus. Conclusions: This is a case of exaggerated vagal response following manipulation of the temporalis muscle. Our report emphasizes the importance for neurosurgeons and anesthesiologists alike to be wary of TCR in order to avoid deleterious consequences when operating on structures associated with the trigeminal nerve.
P.122 Foramen magnum decompression of Chiari malformation using minimally invasive tubular retractors
Authors: Zagzoog N , Reddy K
Published: June 2018

Background: A surgical technique for foramen magnum decompression of Chiari malformation I in 11 patients is described. Methods: We used minimally invasive tubular retractors (METRx Quadrant) attached to a flexible arm to keep the retractor in a fixed position, while allowing flexible angulation under fluoroscopic guidance. Despite the small surgical opening, this approach allowed access to a wide working area, minimized soft tissue exposure, and optimized extent of decompression. For some patients, only the outer layer of dura was opened, but in cases where clinically indicated, a duraplasty was performed. Results: Postoperative CT head demonstrated satisfactory bony removal, and MRI with CSF flow study showed restoration, or significant improvement to CSF flow around the foramen magnum. There was a low incidence of post-operative complications, and the average length of hospital stay was around 1 day (1.2). For 10 out of 11 patients; their symptoms completely resolved on last follow-up, and for those who had syringomyelia, they demonstrated a radiological evidence of syrinx reduction or resolution. Conclusions: Based on our experience with this technique in foramen magnum decompression of Chiari malformation I, minimally invasive tubular retractor is a useful tool, providing the surgeon with enhanced visualization of the operative field, while reducing potential damage to tissue, and optimizing surgical outcomes.
P.135 Autism-associated mutations in SHANK2 increase synaptic connectivity and dendrite complexity in human neurons
Authors: Zaslavsky K , Zhang W , Deneault E , Zhao M , Rodrigues DC , McReady F , Ross PJ , Romm A , Thompson T , Piekna A , Wang Z , Pasceri P , Scherer S , Salter MW , Ellis J
Published: June 2018

Background: Heterozygous loss-of-function mutations in the synaptic scaffolding gene SHANK2 are strongly associated with autism spectrum disorder (ASD). However, their impact on the function of human neurons is unknown. Derivation of induced pluripotent stem cells (iPSC) from affected individuals permits generation of live neurons to answer this question. Methods: We generated iPSCs by reprogramming dermal fibroblasts of neurotypic and ASD-affected donors. To isolate the effect of SHANK2, we used CRISPR/Cas9 to knock out SHANK2 in control iPSCs and correct a heterozygous nonsense mutation in ASD-affected donor iPSCs. We then derived cortical neurons from SOX1+ neural precursor cells differentiated from these iPSCs. Using a novel assay that overcomes line-to-line variability, we compared neuronal morphology, total synapse number, and electrophysiological properties between SHANK2 mutants and controls. Results: Relative to controls, SHANK2 mutant neurons have increased dendrite complexity, dendrite length, total synapse number (1.5-2-fold), and spontaneous excitatory postsynaptic current (sEPSC) frequency (3-7.6-fold). Conclusions: ASD-associated heterozygous loss-of-function mutations in SHANK2 increase synaptic connectivity among human neurons by increasing synapse number and sEPSC frequency. This is partially supported by increased dendrite length and complexity, providing evidence that SHANK2 functions as a suppressor of dendrite branching during neurodevelopment.
P.136 Quantifying potential sources of delay in surgical management of cervical spondylotic myelopathy
Authors: Chan V , Nataraj A
Published: June 2018

Background: Cervical spondylotic myelopathy is a degenerative condition with a variable clinical course. We aim to quantify the sources of potential delay in management and understand how the timing of these events may affect quality of life measures. Methods: The Canadian Spine Outcomes Research Network Registry was used to identify patients older than 18 years of age and have received cervical decompression surgery from January 1, 2013 to March 1, 2016. The primary outcome was the Short Form-12 Physical Component Score at 12-month follow-up. Four time groups were identified: 1) duration of symptoms, 2) time awaiting surgical consult, 3) time spent monitoring symptoms, and 4) time awaiting surgery. -Multivariate regression was used for analysis. Results: A total of 208 patients were identified. The mean age was 59.5 years. 61.53% of patients had symptoms for >12 months at initial consult. Mean time awaiting surgical consult, monitoring symptoms, and awaiting surgery was 77.2, 60.9, and 46.9 days, respectively. Time awaiting surgery (β=-0.032, p=0.04) was a significant factor for change in Physical Component Score. Conclusions: We found time awaiting surgery to be a significant factor on PSC score at 12-month follow-up. Increased time awaiting surgery may result in negative impacts on quality of life outcomes.
GP.05 The risk of malignancy after stereotactic radiosurgery
Authors: Wolf AM , Naylor K , Kondziolka D
Published: June 2018

Background: A major concern of patients undergoing Gamma Knife radiosurgery (GKS) for benign tumors and other conditions is the risk of a separate secondary malignancy or malignant -transformation. The incidence of radiosurgery-associated malignancy based on long-term follow-up remains unknown. Methods: We conducted a population-based cohort study to estimate the incidence rate of both malignant transformation and a separate radiation-associated malignancy in patients undergoing GKS from 1987 to 2016 at 5 centers. Results: 11 527 patients underwent radiosurgery for meningioma (n=3261), arteriovenous malformation (n=2868), trigeminal neuralgia (n=1982), vestibular schwannoma (n=1957), pituitary adenoma (n=1193), other (n=266). The follow-up time ranged from 0.3 to 23.8 years. Four cases of malignant transformation and 3 new malignant brain tumors were reported, two of which were not within the irradiated field. The incidence of malignant transformation was 6.6 per 100 000 patient-years and of new malignancy, either locally or distant, was 5 in 100 000 patient-years. These risks are not higher than the Central Brain Tumor Registry of the United States derived annual incidence rate of all primary malignant CNS tumors of 7.15 per 100 000. Conclusions: Physicians can safely counsel patients that the risk of malignancy after stereotactic radiosurgery remains extremely low, even at long-term follow-up of greater than 10 years.
P.144 Health care utilization by patients seen at a tertiary headache clinic
Authors: Holtby CE , Amoozegar F , Cooke LJ
Published: June 2018

Background: Multidisciplinary treatment programs benefit headache patients. No evidence exists as to whether they change resource use. A historical prospective cohort study was performed to compare the frequency of ambulatory care and emergency department visits for the purposes of headache by patients seen at the Calgary Headache Assessment and Management Program (CHAMP) in the three years before, and after, their first appointment. Methods: Administrative data from Alberta Health was used. All patients seen by a physician at CHAMP from 2003-2013 were included. Sample characteristics were described and the Wilcoxan signed rank sum test was used to compare the number of ambulatory care and emergency department visits in the three years before and after each patient’s first physician appointment at CHAMP. Follow-up visits at CHAMP were excluded from analyses. Results: The median number of ambulatory care visits over three years changed from 4 to 2 (p<0.001). The median number of emergency department visits was zero before and after assessment at CHAMP. The mean number of emergency department visits changed from 1.5 to 1.2 (p<0.0001). Conclusions: Enrollment in a multidisciplinary headache program reduces the number of ambulatory care visits and emergency department visits for purposes of headache.