bluuebunny/crossref_metadata_2025 huggingface dataset:
P.099 Spasticity treatment patterns in long-term care using Ontario real-world evidence
Authors: Khan O , Vo C , Kleiner G
Published: June 2022

Background: Focal spasticity affects up to 1 in 3 residents in long-term care (LTC), with potentially disabling consequences. Data are limited on access to care for patients requiring botulinum toxin (BoNT) treatment in LTC. Methods: This retrospective, observational, real-world study was conducted using the Ontario Drug Benefit claims database. Patients with ≥1 medical claim for BoNT for focal spasticity treatment were selected, and those residing in LTC were further identified. Data were analyzed for the utilization (2000–2019), treatment rate, and time-to-treatment with BoNT in LTC residents (2015–2019). Results: Over a 10-year period, the number of patients receiving BoNT for spasticity increased 7-fold and the proportion of patients residing in LTC versus community increased from 43% (2010) to 52% (2019). Of the LTC residents eligible for BoNT treatment, 33% received BoNT in 2015 compared with 63% in 2019. Injections/patient/year increased from 1.9 (2010) to 3.1 (2017). Following LTC admission, median time to first injection was 2.9 years. Conclusions: In this study, approximately 40% of eligible LTC residents in Ontario were not receiving BoNT treatment, and of those who were, median time to first injection was 2.9 years. Future policy considerations should prioritize uniform access to spasticity standards of care for LTC residents.
P.101 A-waves on electrodiagnostic studies in axonal and demyelinating cases of Guillain-Barré Syndrome (GBS)
Authors: Reiter-Campeau S , Gendron D
Published: June 2022

Background: A-waves are lesser-known late responses of debated clinical significance, seen in routine motor nerve conduction studies (NCS). They are proposed to be a sensitive marker of demyelination and an early finding in acute demyelinating polyradiculoneuropathy (AIDP). We hypothesized that the presence and distribution of A-waves are discriminative markers in differentiating AIDP from axonal variants of Guillain-Barré Syndrome (GBS). Methods: We identified patients diagnosed with demyelinating and axonal forms of GBS at the Montreal Neurological Institute between 2016 and 2021. Clinical and electrophysiological data including raw NCS responses were retrospectively reviewed for 28 AIDP and 9 axonal GBS cases. Results: 20 of 28 AIDP cases had at least one A-wave in non-tibial nerves compared to 2 of 9 axonal cases. Among patients with NCS available within 2 weeks of symptom onset, 13 of 14 AIDP cases had non-tibial A-waves, compared to 0 of 6 axonal cases. Eight of 14 AIDP cases had one or more nerves with multiple A-waves within 2 weeks, compared to 0 of 6 axonal cases. Conclusions: In patients with GBS, the presence of A-waves in non-tibial nerves and of nerves with multiple A-waves are early indicators of the demyelinating variant. Early identification of GBS subtype is valuable for prognostication.
P.105 Using mobile electroencephalography for rapid detection of mild cognitive impairment
Authors: Krigolson OE , Trska R , Bell C , Henri-Bhargava A
Published: June 2022

Background: Mild cognitive impairment (MCI) is a concern for our aging population as it can be a pre-cursor to dementia. However, the diagnosis of MCI can be quite problematic and can come long after initial onset. Here, we sought to use a new technology we have previously validated for research – mobile electroencephalography (mEEG) – to measure brain function to see if we could rapidly detect differences in brain activity between people with and without MCI. Methods: Participants (60: mean age 65) were recruited for a control (30) and an MCI group (30). All participants were screened for MCI using standard RBANS and the MOCA assessments. Participants completed a standard n-Back assessment of working memory while mEEG data was recorded. A key feature here is that we used mEEG technology thus application of the device and the n-Back test was completed in under 10 minutes for each participant. Results: Our key finding is that we observed increased frontal mEEG theta power (brain oscillations between 4 and 7 Hz) for MCI participants relative to controls (p < 0.001). Conclusions: Importantly, our work demonstrates a potential novel rapid brain-based assessment for MCI that would afford earlier detection of disease onset.
P.106 Impact of comorbid sleep disorders in patients with epilepsy on mortality risk
Authors: Lazaj M
Published: June 2022

Background: Pooled mortality has been observed to be almost threefold among people with epilepsy (PWE). Among PWE, epilepsy related deaths (including sudden death in epilepsy (SUDEP)), are commoner than other causes. Among these, around 16-36% are SUDEP, of which 80% events occur during sleep. SUDEP risk is most measured using the SUDEP Risk Inventory. To prevent SUDEP and reduce epilepsy related mortality, we need a better understanding, not only of the components of this screening inventory, but also additional clinical and neurophysiologic parameters that might be commoner among PWE and potentially associated with higher mortality risk. Methods: Patients diagnosed with active epilepsy over the last 3 years will form the study population, categorized into two groups: PWE with a comorbid sleep disorder, and PWE without diagnosis of a sleep disorder. Descriptive statistics will be used to report clinic and neurophysiologic characteristics of subjects enrolled. Results: We hypothesize that there is a significantly increased prevalence of sleep comorbidity among people with epilepsy compared to the general population. Poorer sleep quality could potentially have an association with higher mortality risk among epilepsy patients, Conclusions: We hope to identify and to add sleep factors such as primary sleep disorders and sleep disturbances to already established SUDEP-7 parameters.
P.120 Contrast induced encephalopathy following endovascular therapy for the treatment of cerebrovascular disease
Authors: MacLean MA , Muradov JH , Pickett GE , Friedman A , Weeks A , Volders D
Published: June 2022

Background: Contrast induced encephalopathy (CIE) is an underrecognized, adverse effect of contrast administration during endovascular procedures. A paucity of literature exists regarding CIE following treatment of cerebrovascular disease. As such, we sought to describe our institutional experience with this entity. Methods: We searched our neurovascular database for instances of CIE following endovascular therapy for cerebrovascular disease. We extracted patient data, including demographics, comorbidities, procedural data, symptoms, radiological findings, and treatment. Informed consent was obtained in all cases. Data was analyzed using descriptive statistics. Results: Two patients underwent coiling of cerebral aneurysms; four were treated for ischemic stroke (thromboembolism or large artery atherosclerosis). Mean age was 67.2 years. Risk factors for microvascular dysfunction were identified for most patients: hypertension (100%), obesity (83%), dyslipidemia (83%), prior stroke (83%), renal disease (80%), and connective tissue disorders (33%). Mean operative duration: 284.5 minutes. Mean contrast volume: 285.7 mL. Decreased level of consciousness and lateralizing neurological deficits were the most common CIE-related symptoms. Treatments included intravenous fluids, corticosteroids, and anti-hypertensives. Radiographic findings included effaced cortical sulci, parenchymal edema, and cortical/subarachnoid contrast enhancement. Conclusions: Here, we describe our institutional experience with CIE following endovascular therapy for cerebrovascular disease. We hypothesize that CIE may be facilitated by pre-existing microvascular pathology.
P.122 Unbiased whole brain circuit interrogation reveals neurons restoring walking after spinal cord injury
Authors: Cho N , Squair J , James N , Baud L , Leonhartsberger A , Sveistyte K , Galan K , Barraud Q , Goubran M , Batti L , Pages S , Gautier M , Hutson T , Kathe C , Bichat A , Rizzo O , Hodara M , Bloch J , Courtine G
Published: June 2022

Background: There is presently no cure for locomotor deficits after spinal cord injury (SCI). Very few therapies effectively target the brain due to poor understanding of the brain’s role post-SCI. Newly developed tissue clearing techniques have permitted unbiased three-dimensional circuit analysis, opening new opportunities for SCI-related brain interrogation. Methods: We established a novel brain interrogation pipeline by optimizing mouse brain clearing, imaging, and atlas registration. We leveraged a spontaneous recovery lateral hemisection model to analyze whole brain cell activity and connectivity with the lumbar cord using cFos immunolabelling and virus-mediated projection tracing. We identified a functionally and anatomically dynamic region correlating with recovery and interrogated its locomotor role with optogenetics. We assessed deep brain electrical stimulation (DBS) of this region in a more clinically relevant rat contusion SCI using an established bipedal robotic interface. Results: We unexpectedly uncovered the lateral hypothalamus (LH) to functionally and anatomically correlate with recovery. LHVglut2 optogenetic stimulation significantly augmented locomotor function. LH DBS in rats acutely robustly augmented bipedal locomotion post-SCI. Conclusions: This is the first demonstration of the LH’s role in locomotion post-SCI and is a novel DBS target that robustly augmented locomotor function, dependent on LH glutamatergic cells. LH DBS may be a promising intervention in humans.
P.124 Subnuclear contact localization within the subthalamic nucleus in deep brain stimulation for Parkinson Disease
Authors: Abbass M , Gilmore G , Chalil A , Santyr BG , Parrent AG , MacDougall KW , Lau JC
Published: June 2022

Background: Therapeutic response from subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson disease (PD) has been associated with proximity to an ideal target, commonly in the dorsal sensorimotor STN. Automated registration and atlas-based segmentation has allowed for contact localization within STN subnuclei. We sought to apply these methods to characterize the spatial distribution of our active contact placements. Methods: We conducted a retrospective analysis of 55 patients who underwent bilateral STN DBS for PD. Post-operative CT/MRI scans were non-linearly registered into a standard space, and DBS-electrodes were localized using Lead-DBS. 3-dimensional meshes from a segmented atlas (Ewert 2017) were utilized. Analysis was performed in MATLAB R2019b. Results: Mean active contacts were within sensorimotor STN bilaterally, located posteroinferiorly compared to reported ideal targets. Centroids fell within (left/right): sensorimotor (46%/40%), associative (22%/22%), limbic (0%/2%) and outside STN (32%/36%). Principal components analysis demonstrated most spatial variance is explained by the first component (left 65.8%, right 61.9%). Conclusions: We obtained contact locations in relation to STN subnuclei, allowing for an anatomically guided approach to our analysis. 66% of the active contacts were located within the STN, and most of the spatial variation occurred along a single dimension. Future directions include utilizing subnuclei localizations to investigate clinical outcomes.
P.126 Cyberknife radiosurgery for trigeminal neuralgia: a retrospective review of 168 cases
Authors: Guillemette A , Fournier-Gosselin M , David R , Cynthia M
Published: June 2022

Background: Gamma Knife radiosurgery for the treatment of refractory trigeminal neuralgia is recognized as an efficient intervention. The CyberKnife, a more recent frameless radiosurgery alternative, has not been studied as extensively for this condition. The aim of this study is to evaluate the clinical outcomes of a first CyberKnife radiosurgery treatment on patients with medically refractory trigeminal neuralgia. Methods: A retrospective study of 166 patients (168 cases) with refractory trigeminal neuralgia treated since 2009 with CyberKnife radiosurgery at the Centre Hospitalier de l’Université de Montreal (CHUM). Results: Adequate pain relief (Barrow Neurological Institute (BNI) pain scores I-IIIb) was achieved in 146 cases (86.9%). The median latency period before adequate pain relief was 35 days (range 0-202 days). The median duration of adequate pain relief was 15.8 months (range 0.6-85.0[DR1] [AG2] [AG3] [AG4] months). The actuarial rates of maintenance of adequate pain relief at 12, 36, and 60 months were 77.0%, 62.5%, and 50.2%, respectively. There was a new-onset or aggravation of facial numbness in 44 cases (26.2%). The maintenance of an adequate pain relief was more sustained in idiopathic cases in comparison to cases associated with multiple sclerosis (P< 0.001). Conclusions: In our experience CyberKnife radiosurgery for refractory trigeminal neuralgia is efficacious and safe.
P.140 Development and predictive validation of an intelligent surgical bimanual skills continuous assessment system
Authors: Yilmaz R , Winkler-Schwartz A , Mirchi N , Reich A , Ledwos N , Del Maestro R
Published: June 2022

Background: Surgeons’ bimanual dexterity may correlate with the surgical outcome. Continuous assessment of psychomotor performance enables action-oriented feedback and error avoidance guidance. We outline an artificial intelligence (AI) application to continuously assess surgical bimanual skills and its predictive validation on surgical trainee performance throughout a neurosurgery residency program. Methods: Participants (n=50, 14 experts/neurosurgeons, 14 senior residents, 10 junior residents, 12 novices/medical students) performed two simulated subpial tumour resections a total of 300 times. A deep neural network was developed using expert/neurosurgeon and novice/medical student data to score bimanual performance at 0.2-second intervals between a score of 1.00 and -1.00. An average score was calculated for each task. Results: The average performance score differentiated among four expertise levels, p<.001. Neurosurgeons scored significantly higher than senior residents (p=.045) and junior residents scored significantly higher than medical students (p=.04). The intelligent system also differentiated between senior and junior trainee levels (p=.004). The performance score linearly correlated with resident year of neurosurgical training (adjusted R2=27.7%). Conclusions: The AI-powered intelligent system outlined is the first expert surgeon-data-based technical skills continuous assessment system, with predictive validity throughout a neurosurgical residency program. Intelligent systems may aid in the competency-based approach in surgery by accurately assessing trainee skills.
P.144 Dural arteriovenous fistulas with associated intracranial tumors: review of literature
Authors: Ajisebutu A , Alarifi N
Published: June 2022

Background: Intracranial dural arteriovenous fistulas (DAVF) are relatively rare vascular malformations. While the pathophysiology of their formation is unknown, they are believed to be acquired lesions related to intracranial venous hypertension and dura sinus thrombosis. There have been rare reports of intracranial tumors associated with DAVF. Here we complete a systematic search of the literature. Methods: A systematic PRISMA search of the literature was conducted to identify papers in which an intracranial tumor was associated with sinus thrombosis and DAVF. 24 relevant studies were identified and analyzed, along with a case illustration. Results: A total of 38 cases of DAVF formation with concomitant intracranial tumor were identified. The median age was 60, the majority of tumors being meningiomas (71%), and involved primarily the transverse sigmoid sinus (52%) and superior sagittal sinus (16%). The most cases involved an occlusion (39%) or partial occlusion (24%) of the related sinus. The DAVF were classified as Borden Types I (35%), II (32%) or III (24%). Endovascular treatment was the most common intervention (56%), followed by a combined approach (28%) vs surgery alone (16%), all reporting resolution. Conclusions: This highlights that DAVFs can be rarely associated with intracranial tumors, and highlights the patterns of these lesions and their treatments.
P.148 Action-related fixation in microsuturing, a new gaze behavior metric to differentiate the level of expertise
Authors: Chainey J , Zheng B , Kim M , Elomaa A , Bednarik R , O’Kelly C
Published: June 2022

Background: Gaze behavior differences between expert and novice surgeons have been established in general surgery literature. Limited information is available about surgeon’s visual attention during microsurgery procedures where surgical microscope is used. Methods: 4 experts and 3 novices performed 37 independent sutures under the surgical microscope. Eye movements of surgeons and scene video of the surgical performance were recorded. Total suturing time and subtask times were compared between level of expertise. We defined three discrete surgical actions and examined eye gaze (fixation) directly related to each of these actions. Fixation duration (total, pre-action,and post-action duration) were compared between expert and novice, over 3 subtasks (piercing, exiting and cutting) and between pre- and post-action phases. Results: Expert surgeons completed the suture with shorter total time and displayed longer fixation time than novices. Experts also maintained their visual engagement constantly over the 3 level of subtask in comparison to novices who required a longer fixation time for the challenging subtask (piercing). Experts use longer pre- than post-action fixation, and this pattern is distributed over all three subtasks. This gaze engagement strategy was not shown in novices. Conclusions: The action-related fixation can be used to evaluate microsurgeons’ level of expertise and in surgical education for gaze training.
P.154 Characterizing and comparing brain injury associated with traditional self-retracting brain retractors with novel tubular retractors
Authors: Naeem A , Dryden G , Hammond R , Speechley M , Wade K , Boulton M
Published: June 2022

Background: Tubular retractors are FDA approved and in the Neurosurgical marketplace, but adaptation has been hampered by lack of evidence showing superiority over traditional retractors when performing subcortical surgery. This study examines brain injury associated with traditional brain retractors versus tubular retractors. Methods: Nine porcine models underwent a simulated neurosurgical operation. Retractors were inserted for four hours after which the porcine model was euthanized. The en-bloc extracted porcine brain was fixed in 10% formalin, paraffin embedded, sectioned at 4 um and stained with hematoxylin and eosin (H&E) using standard laboratory protocols. Computer algorithms were generated to calculate areas of cerebral edema and hemorrhage adjacent to retractor surfaces. Results: Using a two-tailed t-test with a significance level of 0.05, traditional brain retractors were associated with statistically significantly greater cerebral edema when compared to tubular retractors (17.36 um2 vs. 12.42 um2; p = 0.0038). There was no statistically significant difference in mean areas of hemorrhage between traditional brain retractors and tubular retractors noted (3.43 um2 vs 3.60 um2; p = 0.8297). Conclusions: Tubular retractors are associated with significantly less edema in surrounding brain than traditional retractors. On histopathological merits, this study supports the application of tubular retractors over traditional retractors.
P.165 Using artificial intelligence to quantify dynamic retraction of brain tissue and the manipulation of instruments in neurosurgery
Authors: Martin T , El Hage G , Bojanowski MW
Published: June 2022

Background: There is no objective way to measure the amount of manipulation and retraction of neural tissue by the surgeon. Our objective is to develop metrics quantifying dynamic retraction of cerebral tissue and the manipulation of instruments during a neurosurgical intervention. Methods: We trained a convolutional neural network to analyze microscopic footage of neurosurgical procedures and thereby generate metrics evaluating the surgeon’s dynamic retraction of brain tissue and the surgeon’s manipulation of the instruments themselves. U-Net image segmentation is used to output bounding polygons around cerebral parenchyma of interest, as well as the vascular structures and cranial nerves. Results: On the validation set, our network achieves a state of the art Intersection over Union (IoU) of 70.1% (Recall = 89%) and 74.3% (Recall = 91%) for surgical tools and biological structures respectively. Multivariate statistical analysis was used to evaluate dynamic retraction and tissue handling. Conclusions: We describe a semantic segmentation model for surgical instruments and intracranial structures to evaluate dynamic retraction of soft tissue and manipulation of instruments during a surgical procedure, while accounting for movement of the operative microscope. Using the intraoperative footage, this model can potentially provide the surgeon with objective feedback.
P.169 Tissue plasminogen activator in addition to twist drill drainage as a treatment for chronic subdural hematomas – a descriptive analysis
Authors: Dickinson A , leRoux A , Kolyvas G , El-Mughayyar D , Ghallab N , Bigney E , Richardson E , Vandewint A , Attabib N
Published: June 2022

Background: Current literature provides little consensus on universal guidelines for first-line treatment of chronic subdural hematomas (cSDH). However, administration of local tissue plasminogen activator (tPA) may enhance the traditional method of twist drill drainage (TDD). The study aims to explore the efficacy of TDD with and without tPA, at achieving clinically relevant drainage (200mL) and reducing recurrence of cSDH. Methods: A retrospective review of patients (N=34) with cSDH is presented. Patients who received TDD with tPA (n=17) were identified and matched, based primarily on age and hematoma volume, to a control group (n=17), TDD without tPA. Variables of interest include initial hematoma volume, volume drained, length of stay, and recurrence rates. Descriptive analysis was run. Results: Average age for patients was 74.6 with 76% male. Mean drainage volumes for the tPA cohort was 381.6mL and TDD without tPA cohort was 151.3mL. The addition of tPA resulted in drainage volumes nearly double (1.9x) the clinically relevant amount and had low recurrence rates (12.5%). TDD without tPA failed to result in clinically relevant drainage and had a recurrence rate of 52.9%. Average length of stay differed by two days (9.71 tPA; 7.71 control). Conclusions: TDD with tPA was effective at treating cSDH in our population.
P.173 Evaluating instability in Degenerative Lumbar Spondylolisthesis: objective variables versus surgeon impressions
Authors: MacLean MA , Bailey C , Fisher C , Rampersaud R , Greene R , Glennie A
Published: June 2022

Background: The qualitative Degenerative Spondylolisthesis Instability Classification (DSIC) system defines pre-operative instability associated with degenerative lumbar spondylolisthesis (DLS) and facilitates surgical technique selection. Objectives: (1) propose a quantitative DSIC system; (2) compare objective measures to surgeon impressions of DLS-related instability. Methods: We conducted a multi-center prospective study of 408 adult patients undergoing surgery for DLS. Variables included in the quantitative classification were assigned point-values based on evidence quality. Scores were converted to DSIC Types: 0-2 points (“Stable”; Type I), 3 points (“Potentially Unstable”; Type II), 4-5 points (“Unstable”; Type III). Surgeons documented impressions of instability using the qualitative DSIC system. Results: Five variables were included in the quantitative DSIC: presence of facet effusion, preservation of disc height (<6.5mm), translation (>4mm), kyphotic or neutral disc angle in flexion, and presence of low back pain (LBP) (>5/10 intensity). Surgeons categorized higher degrees of instability than the preliminary quantitative DSIC system, in 130 patients (42%) (P < 0.001). Compared to procedures suggested by the quantitative DSIC system, more extensive surgical procedures were performed in 150 patients (57%) (P < 0.001). Conclusions: A quantitative DSIC system allowed DLS-related stability to be scored and categorized. Patients potentially received more extensive surgery than warranted based on quantitative assessments of stability.
P.177 Assessing lesion severity in a mouse model of intracerebral hemorrhage
Authors: Pendleton N , Sylvian N , Hou H , Pushie J , Kelly M , Peeling L
Published: June 2022

Background: Intracerebral hemorrhage (ICH) is caused by the rupture of a blood vessel, resulting in bleeding into the brain. This type of stroke accounts for 12-15% of all strokes and is the most fatal type of stroke (40% mortality rate). ICH stroke presents a greater burden to survivors as 90% of ICH survivors have some degree of disability. Because of the poor patient outcomes, there is a clear need for identifying new treatments as well as establishing the efficacy of existing treatments. Methods: Using previously described techniques we aim to establish a mouse model of ICH at the University of Saskatchewan. We observed them at a 1- 24-, 48- and 72hr mark post-stroke and scored for neurological deficits. Results: We currently have conducted 23 model trials. We have data on mice at 1-, 24, and 72 hr post-stroke. We have observed and begun to analyze a lesion area that can be seen in H&E stained sections, and further assessed with FTIR, and synchrotron modalities. Conclusions: We have analyzed several of the specimens with FTIR imaging and synchrotron analysis with the Canadian Light Source. We have preliminary results of the progression of metabolites in the hematoma and peri-hematoma zone of the ICH.
GP.2 Deep learning prediction of response to disease modifying therapy in primary progressive multiple sclerosis
Authors: Falet JR , Durso-Finley J , Nichyporuk B , Schroeter J , Bovis F , Sormani M , Precup D , Arbel T , Arnold DL
Published: June 2022

Background: Only one disease modifying therapy (DMT), ocrelizumab, was found to slow disability progression in primary progressive multiple sclerosis (PPMS). Modeling the conditional average treatment effect (CATE) using deep learning could identify individuals more responsive to DMTs, allowing for predictive enrichment to increase the power of future clinical trials. Methods: Baseline clinical and MRI data were acquired as part of three placebo-controlled randomized clinical trials: ORATORIO (ocrelizumab), OLYMPUS (rituximab) and ARPEGGIO (laquinimod). Data from ORATORIO and OLYMPUS was separated into a training (70%) and testing (30%) set, while ARPEGGIO served as additional validation. An ensemble of multitask multilayer perceptrons was trained to predict the rate of disability progression on both treatment and placebo to estimate CATE. Results: The model could separate individuals based on their predicted treatment effect. The top 25% of individuals predicted to respond most have a larger effect size (HR 0.442, p=0.0497) than the entire group (HR 0.787, p=0.292). The model could also identify responders to laquinimod. A simulated study where the 50% most responsive individuals are randomized would require 6-times less participants to detect a significant effect. Conclusions: Individuals with PPMS who respond favourably to DMTs can be identified using deep learning based on their baseline clinical and imaging characteristics.
GP.4 The epilepsy surgery experience in children with infantile spasms at a tertiary care centre in Canada
Authors: Gettings J , Shafi S , Boyd J , Snead O , Rutka J , Drake J , McCoy B , Jain P , Whitney R , Go C
Published: June 2022

Background: Infantile spasms (IS) is an epileptic encephalopathy, characterized by spasms, hypsarrhythmia, and developmental regression. This is a retrospective case series of children with IS who underwent epilepsy surgery at The Hospital for Sick Children (HSC) in Toronto, Canada. Methods: The records of 223 patients seen in the IS clinic were reviewed. Results: Nineteen patients met inclusion criteria. The etiology of IS was encephalomalacia in six patients (32%), malformations of cortical development in 11 patients (58%), atypical hypoglycaemic injury in one patient (5%), and partial hemimegalencephaly in one patient (5%). Nine patients (47%) underwent hemispherectomy and 10 patients (53%) underwent lobectomy/lesionectomy. Three patients (16%) underwent a second epilepsy surgery. Fifteen patients (79%) were considered ILAE Seizure Outcome Class 1 (completely seizure free; no auras). The percentage of patients who were ILAE Class 1 at most recent follow-up decreased with increasing duration of epilepsy prior to surgery. Developmental outcome was improved in 14/19 (74%) and stable in 5/19 (26%) patients. Conclusions: Our study found excellent seizure freedom rates and improved developmental outcomes following epilepsy surgery in patients with a history of IS with a structural lesion detected on MRI brain.
A.1 Changes in ischemic stroke presentations and associated workflow during the first wave of the COVID-19 pandemic: A population study
Authors: Ganesh A , Stang JM , McAlister FA , Shlakhter O , Holodinsky JK , Mann B , Hill MD , Smith EE
Published: June 2022

Background: Pandemics may promote hospital avoidance among patients with emergencies, and added precautions may exacerbate treatment delays. Methods: We used linked administrative data and data from the Quality Improvement and Clinical Research Alberta Stroke Program – a registry capturing stroke-related data on the entire Albertan population (4.3 million) – to identify all patients hospitalized with stroke in the pre-pandemic (01/01/2016-27/02/2020) and COVID-19 pandemic (28/02/2020-30/08/2020) periods. We examined changes in stroke presentation rates and use of thrombolysis and endovascular therapy (EVT), adjusted for age, sex, comorbidities, and pre-admission care needs; and in workflow, stroke severity (National Institutes of Health Stroke Scale/NIHSS), and in-hospital outcomes. Results: We analyzed 19,531 patients with ischemic stroke pre-pandemic versus 2,255 during the pandemic. Hospitalizations/presentations dropped (weekly adjusted-incidence-rate-ratio[aIRR]:0.48,95%CI:0.46-0.50), as did population-level incidence of thrombolysis (aIRR:0.49,0.44-0.56) or EVT (aIRR:0.59,0.49-0.69). However, proportions of presenting patients receiving thrombolysis/EVT did not decline (thrombolysis:11.7% pre-pandemic vs 13.1% during-pandemic, aOR:1.02,0.75-1.38). For out-of-hospital strokes, onset-to-door times were prolonged(adjusted-coefficient:37.0-minutes, 95%CI:16.5-57.5), and EVT recipients experienced greater door-to-reperfusion delays (adjusted-coefficient:18.7-minutes,1.45-36.0). NIHSS scores and in-hospital mortality did not differ. Conclusions: The first COVID-19 wave was associated with a halving of presentations and acute therapy utilization for ischemic stroke at a population level, and greater pre-/in-hospital treatment delays. Our data can inform public health messaging and stroke care in future pandemic waves.
A.2 Identification of predictors of response to Erenumab in episodic and chronic migraine in a cohort of patients: a preliminary analysis
Authors: Salem-Abdou H , Puymirat J
Published: June 2022

Background: Erenumab is an antibody anti-calcitonin gene related peptide (CGRP) receptor approved for the treatment of episodic (EM) and chronic migraine (CM). In this study, we aimed to identify the predictors of response to the treatment. Methods: This is an ongoing retrospective cohort study of 120 patients (49 with cervicalgia) with EM or CM treated with Erenumab. The first endpoint was to identify the success rate of this treatment (at least 50% reduction in monthly migraine days during the third month of the treatment). The second endpoint was to identify the predictors of response to Erenumab treatment. Results: Seventy one percent of patients achieved a favorable response (P-value<0.001) to Erenumab. Patients with cervicalgia showed a lower treatment success rate (21.1% with vs 40.8% without cervicalgia) while patients without cervicalgia showed a higher treatment success rate (78. 9% without vs 59.2% with cervicalgia) with a P-value of 0.025 and an odd ratio of 0.388 (95% CI 0.174-0.869, P-value=0.021). A similar trend was observed in patients with occipital neuralgia and obesity (P-value<0.08). Conclusions: The preliminary analysis of this study demonstrates that cervicalgia (and to a lesser extend occipital neuralgia and obesity) is a negative predictor of response to Erenumab in patients with migraine.
A.4 Entropy on routine EEG: an interictal marker of seizure frequency?
Authors: Lemoine É , Tessier J , McDuff G , Robert M , Toffa D , Lesage F , Nguyen DK , Bou Assi E
Published: June 2022

Background: Sample entropy (SampEn) can quantify the unpredictability of a physiological signal. We sought to assess if SampEn on EEG could reflect recent seizure activity. Methods: Charts of all patients undergoing an outpatient EEG between January and March 2018 were reviewed to assess seizure occurrences in the follow-up period between the two clinical visits surrounding the EEG. 9s-EEG segments were extracted at pre-specified time points. SampEn was calculated for all segments and values aggregated at the 25thpercentile. We performed a multivariate zero-inflated analysis to test the association between SampEn and seizure rate around the EEG, after controlling for age, presence of IED, presence of abnormal slowing, and presence of a focal brain lesion. Results: 269 EEGs were screened and 133 met inclusion criteria (112 patients). 80 EEGs (60%) were from patients with epilepsy, of which 47 had at least one seizure within the year preceding the EEG. Remaining EEGs were from patients who were deemed not to have epilepsy at last follow-up. Each 1SD decrease in SampEn was associated with a 3.93-fold increase in the rate of daily seizures (95% CI: 1.19–12.99, p = 0.02). Conclusions: Sample entropy of EEG is a potential objective method to assess contemporary seizure occurrence.
Textual, Material, Visual: Exploring an Epigraphic Approach to the History of Imperial China
Authors: Wang Jinping
Published: June 2022

In this article, I advance a recent epigraphic approach to historical study by foregrounding steles as a medium that functions both to communicate information and project authority publicly. Scholars taking this approach have explored distinctive genres of steles to transform our understanding of north China under Mongol rule. Through a case study, I show how a set of steles installed in the fifteenth-century rural world of north China transmitted authority and power not just through the content of their inscriptions but also through other written and unwritten information they stored. I give particular attention to the ways in which the inscriptions were materialized and visualized. In doing so, I argue that emphasizing the public communication function of steles challenges us to think beyond primary sources strictly in terms of their textual value to reflect more broadly on modes of transmission and the power dynamics contained within them.
From ice core to ground-penetrating radar: representativeness of SMB at three ice rises along the Princess Ragnhild Coast, East Antarctica
Authors: Cavitte Marie G.P. , Goosse Hugues , Wauthy Sarah , Kausch Thore , Tison Jean-Louis , Van Liefferinge Brice , Pattyn Frank , Lenaerts Jan T.M. , Claeys Philippe
Published: June 2022

The future contributions of the Antarctic Ice Sheet to sea level rise will depend on the evolution of its surface mass balance (SMB), which could amplify/dampen mass losses increasingly observed at the ice sheet's edge. In situ constraints of SMB over annual-to-decadal timescales consist mostly of firn/ice cores that have a surface footprint $\sim$cm$^{2}$. SMB constraints also come from climate models, which have a higher temporal resolution but a larger surface footprint of several km$^{2}$. We use ice-penetrating radar data to obtain an intermediate spatial and temporal resolution SMB record over three ice rises along the Princess Ragnhild Coast. The co-located ice cores allow us to obtain absolute radar-derived SMB rates at a multi-annual-to-decadal temporal resolution. By comparing the ice core SMB measurements and the radar-derived SMB records, we determine that pointwise measurements of SMB are representative of a small surface area, $\sim 200-500$ m radius extending from the ice core drill site for the ice rises studied here, and that the pointwise measurements are systematically 7–15 cm w.e. a$^{-1}$ lower than the mean SMB value calculated for the whole ice rises. However, ice core records are representative of an entire ice rise's temporal variability at the temporal resolution examined.
Ruin probabilities with investments: smoothness, inegro-differential and ordinary differential equations, asymptotic behavior
Authors: Kabanov Yuri , Pukhlyakov Nikita
Published: June 2022

This study deals with the ruin problem when an insurance company having two business branches, life insurance and non-life insurance, invests its reserves in a risky asset with the price dynamics given by a geometric Brownian motion. We prove a result on the smoothness of the ruin probability as a function of the initial capital, and obtain for it an integro-differential equation understood in the classical sense. For the case of exponentially distributed jumps we show that the survival (as well as the ruin) probability is a solution of an ordinary differential equation of the fourth order. Asymptotic analysis of the latter leads to the conclusion that the ruin probability decays to zero in the same way as in the already studied cases of models with one-sided jumps.
Concilier les approches sociohistoriques et les approches ethnographiques dans l’étude du nationalisme : une analyse de cas de la résonnance de la bataille des Éperons d'or en Flandre
Authors: Poitras Dave , Dufour Frédérick Guillaume
Published: June 2022

Cet article a pour point de départ la querelle épistémologique survenue entre Anthony D. Smith et Jon E. Fox et Cynthia Miller-Idriss concernant les différentes approches du champ d’études du nationalisme. Alors que Fox et Miller-Idriss rejettent la pertinence d'une approche sociohistorique dans l’étude ethnographique du nationalisme, Smith considère l'ethnographie comme une pratique descriptiviste dénuée d'intérêt scientifique qui, de surcroit, fait abstraction des recherches sur la nation conduite au cours des dernières décennies. Afin de dénouer cette impasse, nous proposons une démarche méthodologique visant à concilier ces deux approches par l'entremise du concept de lieu de mémoire. À partir d'une étude de cas, la bataille des Éperons d'or et sa résonance dans les pratiques discursives, nous illustrons comment l'historicité du fait national peut s'avérer essentielle pour comprendre le fonctionnement de la nation au quotidien et nous éclairer sur la manière dont les Flamands se construisent en tant que sujets nationaux.
The Art of the Deal or ‘Abandoning’ Self-Determination? US Recognition of Morocco's Territorial Sovereignty over Western Sahara
Authors: Borgen Christopher J
Published: June 2022

This article considers the recent recognition by the United States of Morocco's territorial sovereignty over Western Sahara. After a review of certain aspects of the history of the dispute over Western Sahara, it focuses on the interaction of arguments based on the recognition and non-recognition of territorial sovereignty with those prioritising the right of self-determination of the Sahrawi people. It concludes that, in as much as the population of Western Sahara has a right to decide its own future, US recognition of Morocco's sovereignty over Western Sahara has undermined key principles of international law.
Mobile robots path planning and mobile multirobots control: A review
Authors: Hichri Bassem , Gallala Abir , Giovannini Francesco , Kedziora Slawomir
Published: June 2022

Mobile robots and multimobile robotic system usage for task achievement have been an emerging research area since the last decades. This article presents a review about mobile robot navigation problem and multimobile robotic systems control. The main focus is made on path planning strategies and algorithms in static and dynamic environments. A classification on mobile robots path planning has been defined in the literature and divided to classical and heuristic approaches. Each of them has its own advantages and drawbacks. On the other hand, the control of multimobile robots is presented and the control approaches for a fleet of robots are presented. Scientists found that using more than one robot as opposed to a single one presents many advantages when considering redundant task, dangerous tasks, or a task that scales up or down in time or that requires flexibility. They have defined three main approaches of multiple robots control: behavior-based approach, leader–follower approach, and virtual structure approach. This article addresses these approaches and provides examples from the literature.
Passive with control and raising in mainland Scandinavian
Authors: Engdahl Elisabet
Published: June 2022

This article gives an overview of the use of non-local passives in mainland Scandinavian, i.e. passives where the subject of the first verb is a thematic argument of a second verb. Three factors are important: whether V1 is a control verb or a raising passive, whether V2 is a passive participle or an infinitive and whether the passive is morphological or periphrastic. Danish and Norwegian allow passive control verbs such as forsøge ‘try’ with passive participles whereas this pattern is only found with semi-control verbs like begära ‘request’ in Swedish. In Swedish there is an alternative strategy for strict control verbs, viz. active control verb plus passive infinitive. All three languages allow both passive infinitival complements and passive participles with raising passives such as påstås ‘is claimed’. These passive constructions need to be distinguished from so called long passives and double passives where a passive feature on either V1 or V2 can spread to the adjacent verb.
Carbon Border Measures, Environmental Effectiveness and WTO Law Compatibility: Is There a Way Forward for the Steel and Aluminium Climate Club?
Authors: Leonelli Giulia Claudia
Published: June 2022

With its narrow focus on price-based policies and ‘explicit’ carbon prices, the EU carbon border adjustment mechanism (CBAM) aims to prevent carbon leakage by ensuring that imported products ‘bear’ the same exact economic costs ‘borne’ by EU products. The proposed US border carbon adjustment (BCA) and the recent proposal for a global steel and aluminium arrangement (GSAA), by contrast, reflect a broader focus on environmental equivalence and recourse to punitive or quasi-punitive remedies. All recently proposed carbon border measures suffer from specific limitations. Further, albeit to a different extent, they are all associated with problematic aspects in terms of WTO law compatibility. This research note enquires whether the GSAA could be fine-tuned at the regulatory design stage in such a way as to provide an environmentally effective and WTO law compatible way forward. The analysis illustrates that recourse to an installation-based approach, emission limit values and product standards would achieve these goals. Nonetheless, the implementation of this ambitious strategy would be fraught with political obstacles.
About Waiting: A Reading from Social Policies and Emotions in the Context of a Pandemic
Authors: Cena Rebeca , Dettano Andrea
Published: June 2022

The pandemic declared in 2020 has implied extreme transformations. In the Argentine case, measures were announced to provide relief to the sectors defined as the most affected, within which the so-called emergency family income (EFI) was established. The EFI’s management, implementation, access and collection method underwent a digitalisation process, enabling access through official and nonofficial channels. The nonofficial channels include Facebook Groups, where the recipients of social policies exchange information, doubts and advice. This article, based on virtual ethnography, aims to explore the emotions linked to the management and perception of EFI. In particular, we address a practice that has become relevant in the aforementioned context: waiting. It has been observed that the barriers between registration and access to the EFI transfer have implied different types of waiting on the part of the receiving population. We conclude that waiting has become an operative element in the implementation of social policies.
Immunity Ratione Materiae of the Marines as Vessel Protection Detachments: A Case Note on the M/V Enrica Lexie Case
Authors: ISHII Yurika
Published: June 2022

This case note critically analyses the logic of M/VEnrica Lexieof 2020 with a particular focus on the issue of the immunityratione materiae. This judgment is important in terms of the development of the principle of sovereign immunity. It first reviews the background of the case and the judgment. It then examines (1) the basis of the principle of sovereign immunity and (2) the territorial exception and its relevance to the law of the sea. It criticizes the logic of the judgment, particularly on its reference to the United Nations Convention on Jurisdictional Immunities of States and Their Property, regardless of the fact that the instrument only applies to civil proceedings. Finally, it comments on the Award's implication for anti-piracy international cooperation.
Data Fusion of Total Solar Irradiance Composite Time Series Using 41 Years of Satellite Measurements
Authors: Montillet J.‐P. , Finsterle W. , Kermarrec G. , Sikonja R. , Haberreiter M. , Schmutz W. , Dudok de Wit T.
Published: June 2022

Since the late 1970s, successive satellite missions have been monitoring the sun's activity and recording the total solar irradiance (TSI). Some of these measurements have lasted for more than a decade. In order to obtain a seamless record whose duration exceeds that of the individual instruments, the time series have to be merged. Climate models can be better validated using such long TSI time series which can also help to provide stronger constraints on past climate reconstructions (e.g., back to the Maunder minimum). We propose a 3‐step method based on data fusion, including a stochastic noise model to take into account short and long‐term correlations. Compared with previous products scaled at the nominal TSI value of ∼1361 W/m2, the difference is below 0.2 W/m2 in terms of solar minima. Next, we model the frequency spectrum of this 41‐year TSI composite time series with a Generalized Gauss‐Markov model to help describe an observed flattening at high frequencies. It allows us to fit a linear trend into these TSI time series by joint inversion with the stochastic noise model via a maximum‐likelihood estimator. Our results show that the amplitude of such trend is ∼−0.004 ± 0.004 W/(m2yr) for the period 1980–2021. These results are compared with the difference of irradiance values estimated from two consecutive solar minima. We conclude that the trend in these composite time series is mostly an artifact due to the colored noise.