bluuebunny/crossref_metadata_2025 huggingface dataset:
P.048 Monitoring and managing gastrointestinal events with sodium phenylbutyrate and ursodoxicoltaurine for the treatment of Amyotrophic Lateral Sclerosis
Authors: Bonnyman S , Jason T
Published: June 2023

Background: Sodium phenylbutyrate and ursodoxicoltaurine/taurursodiol (PB&TURSO) is indicated for the treatment of amyotrophic lateral sclerosis (ALS) in Canada and the U.S. In the CENTAUR trial, a phase 2 U.S. multicenter trial in ALS, PB&TURSO was generally well-tolerated. The most common adverse reactions were gastrointestinal (GI) and occurred most often during the first three weeks of therapy. Although the occurrence of GI events in people living with ALS (PLWALS) and treated with PB&TURSO are recognisable and generally manageable, many of the symptoms are often not managed proactively. We sought to develop an evidence-based tool to help guide clinicians on managing diarrhea and abdominal pain in PLWALS and treated with PB&TURSO. Methods: Three ALS specialized neurologists and one gastroenterologist combined their clinical experience, research, and each Medications respective product monograph, to develop a patient-centric GI tool. Results: A guide to monitoring and managing potential GI events with PB&TURSO was developed. The tool provides clinicians a proactive, step-by-step guide to help manage diarrhea and abdominal pain in PLWALS treated with PB&TURSO. Conclusions: The GI tool has the potential to improve monitoring, recognition, and treatment of GI events in PLWALS treated with PB&TURSO. Proactively managing GI events may aid medication adherence and improve patient quality of life.
P.057 A case of cerebral fat embolism in the absence of right-to-left shunt
Authors: Aminian KS
Published: June 2023

Background: A 64-year-old man underwent an elective right total hip arthroplasty. Post-operatively, his GCS was 6, despite reversal of anesthetic agents. His toes were upgoing bilaterally. He did not have other focal neurologic deficits. He was intubated for airway protection. His only vascular risk factor was hypertension. Methods: [Case Report]Results: A CT/CTA/CTP head was unremarkable. A 1.5T MRI showed a few tiny, bihemispheric, embolic infarcts. These were not significant enough to account for his decreased level of consciousness. His blood work did not show evidence of coagulopathy. A subsequent 3T MRI demonstrated widespread, tiny embolic infarcts in a starfield pattern, consistent with cerebral fat embolism. A transesophageal echocardiogram with bubble study failed to demonstrate a right-to-left shunt. By post-operative day 11, he returned to his neurological baseline. Conclusions: A high degree of suspicion is required to diagnose cerebral fat embolism. There are reports of cerebral fat embolism in the absence of right-to-left shunt. The proposed mechanism is physiologic stress leading to systemic release of free fatty acids and inflammatory mediators, which damage capillary beds and disrupt the blood-brain barrier. This diagnosis has important prognostic implications as fat vacuoles deform easily and deficits are typically more reversible than those occurring with other embolic events.
P.062 A study of stroke-related experiences and priorities of elderly living with dementia, their family caregivers and physicians
Authors: Betzner WR , Ganesh A
Published: June 2023

Background: Around 10% of ischemic stroke patients have pre-existing dementia and are excluded from stroke trials and routine care. Little is known about physician practices in the stroke care of people living with dementia (PLWD) leading to limited understanding of their experiences, priorities, and outcomes. This study aims to better understand PLWD through in-depth interviews. Methods: This study employs a qualitative descriptive methodology with two sets of 20 semi-structured interviews with PLWD and their primary caregivers (dyads), and with stroke physicians. Interviews with dyads investigate their experiences, priorities, and attitudes towards stroke care. Participants will be recruited through snowball sampling and interviews will be analyzed through qualitative data analysis software. Results: Initial analyses of the PLWD-caregiver dyad interviews have been completed, revealing themes of independence, uncertainty about the future, and fears of another stroke. Conclusions: As the population ages, stroke teams will likely encounter more PLWD. Engaging PLWD and their caregivers is crucial to better understand their experiences and priorities, which will inform future studies and improve their care. The findings from the dyad and physician interviews will be relevant to a broad audience, including patients, caregivers, physicians, researchers, and policymakers.
P.065 Comparison in outcomes by sex in acute ischemic stroke patients treated with alteplase versus tenecteplase: a subgroup analysis of AcT
Authors: Kim DJ , Singh N , Catanese L , Buck BH , Deschaintre Y , Coutts SB , Khosravani H , Appireddy R , Moreau F , Gubitz G , Tkach A , Dowlatshahi D , Medvedev G , Mandzia J , Pikula A , Shankar J , Williams H , Manosalva H , Siddiqui M , Zafar A , Imoukhuede O , Hunter G , Phillips S , Hill MD , Poppe AY , Ademola A , Shamy M , Bala F , Sajobi TT , Swartz RH , Almekhlafi M , Menon BK , Field TS
Published: June 2023

Background: Sex differences in treatment response to intravenous thrombolysis (IVT) are poorly characterized. We compared sex-disaggregated outcomes in patients receiving IVT for acute ischemic stroke in the Alteplase compared to Tenecteplase (AcT) trial, a Canadian multicentre, randomised trial. Methods: In this post-hoc analysis, the primary outcome was excellent functional outcome (modified Rankin Score [mRS] 0-1) at 90 days. Secondary and safety outcomes included return to baseline function, successful reperfusion (eTICI≥2b), death and symptomatic intracerebral hemorrhage. Results: Of 1577 patients, there were 755 women and 822 men (median age 77 [68-86]; 70 [59-79]). There were no differences in rates of mRS 0-1 (aRR 0.95 [0.86-1.06]), return to baseline function (aRR 0.94 [0.84-1.06]), reperfusion (aRR 0.98 [0.80-1.19]) and death (aRR 0.91 [0.79-1.18]). There was no effect modification by treatment type on the association between sex and outcomes. The probability of excellent functional outcome decreased with increasing onset-to-needle time. This relation did not vary by sex (pinteraction 0.42). Conclusions: The AcT trial demonstrated comparable functional, safety and angiographic outcomes by sex. This effect did not differ between alteplase and tenecteplase. The pragmatic enrolment and broad national participation in AcT provide reassurance that there do not appear to be sex differences in outcomes amongst Canadians receiving IVT.
P.067 The decision to revascularize in symptomatic non-stenotic carotid disease: results from the Hot Carotid Qualitative study
Authors: MacLean D , Beland B , Jewett G , Bartolini L , Campbell DJ , Varma M , Singh R , Al-Sultan A , Wong J , Menon B , Ganesh A
Published: June 2023

Background: Little evidence exists to guide the management of symptomatic non-stenotic carotid disease (SyNC). SyNC, which refers to carotid lesions with less than 50% artery stenosis, has been increasingly implicated as a cause of stroke and TIA. Methods: Semi-structured interviews with 22 stroke physicians from 16 centers were conducted as part of the Hot Carotid Qualitative Study. This study explored decision-making approaches, opinions and attitudes regarding the management of symptomatic carotid disease. Presented here are a subset of results related to the decision to revascularize patients with SyNC. Results: Thematic analysis revealed equipoise in the decision to revascularize patients with SyNC. Participants discussed a desire to use imaging features (e.g plaque rupture and plaque morphology) to inform the decision to revascularize, though significant uncertainty remains in appraising the risk conferred by certain features. Experts support further study to better understand the use of these features in risk appraisal for patients with SyNC. Conclusions: The decision to revascularize patients with SyNC is an area with significant equipoise. Experts identify the use of imaging features as an important tool in informing the decision to pursue revascularization in patients with SyNC though more study is required in this area to better inform practice.
P.072 Alberta Spinal Muscular Atrophy Newborn Screening (SMA-NBS) – 2022 results
Authors: Mah JK , Price TR , Kolski H , Ridsdale R , Parboosingh J , Niri F
Published: June 2023

Background: Spinal muscular atrophy (SMA) is a progressive neuromuscular disease caused by biallelic mutations of the survival motor neuron 1 (SMN1) gene. Early diagnosis via newborn screening and presymptomatic treatment are essential to optimize health outcomes for affected individuals. Methods: We developed a multiplex real-time polymerase chain reaction assay using dried blood spot samples for the detection of homozygous deletion of exon 7 of the SMN1 gene. Newborns who were screened positive were seen urgently for clinical evaluations. Copy numbers of SMN1 and SMN2 genes were determined by multiplex ligation-dependent probe amplication for confirmatory testing. Results: From February 28, 2022 to December 31, 2022, 42,450 newborns were screened in Alberta. Four infants had abnormal screen results and were subsequently confirmed to have SMA. No false positive newborns were detected. Three infants received adeno-associated virus serotype 9 (AAV9)-mediated SMN1 gene replacement therapy <31 days of age. One infant received SMN2-splicing modulator treatment due to maternally-transferred AAV9 neutralizing antibodies prior to gene therapy at 3 months of age. Conclusions: The estimated incidence of SMA in Alberta is 9.4 (95% CI: 2.5 – 24.1) per 100,000 live-births. During the first year of the SMA-NBS program, 4 asymptomatic infants received treatment and demonstrated excellent developmental progress to date.
P.073 Mapping a national Duchenne muscular dystrophy registry to the International Classification of Functioning, Disability, and Health
Authors: Bourcier D , Koenig N , Hodgkinson V , Worsfold N , Osman H , Mortenson P , Korngut L , Bohne L , Sheriko J
Published: June 2023

Background: Duchenne muscular dystrophy (DMD) is an X-linked disease that causes progressive muscle wasting. The Canadian Neuromuscular Disease Registry (CNDR) DMD subset collects data focused on body structure and function. Our objective is to develop a broader dataset including the priorities of those living with DMD in accordance with the International Classification of Functioning, Disability, and Health (ICF) – a framework for describing disease and health functions developed by the World Health Organization. Methods: Clinically relevant ICF categories for DMD were identified and reviewed by two independent committees including two patients and six parent representatives. The Delphi approach was used to narrow ICF categories to a core set representative of DMD, which will be mapped to the CNDR-DMD subset. Results: With full result expected by the conference, the mapping of the ICF to the CNDR-DMD subset will identify data collection priorities in the four domains of functioning and disability: body functions and structures, activities at the level of the individual, participation in all areas of life, and environmental factors. Conclusions: The ICF can be used to identify data collection priorities. Broadening the CNDR-DMD subset will foster future research to include outcome measures important to patients and families affected by DMD.
P.082 White matter abnormalities suggestive of multiple sclerosis in Wolfram syndrome: report of two unrelated cases
Authors: Simo J , Ashton C , Rouleau G , Nadjar Y , La Piana R
Published: June 2023

Background: Wolfram syndrome (WFS) is a genetic disorder clinically characterized by optic atrophy (OA), diabetes mellitus, sensorineural deafness, and diabetes insipidus. It is caused by mutations in WFS1 (mono- or biallelic) or CISD2 (biallelic) genes. Neuroradiological features include cerebellar and/or brainstem atrophy with visual pathway and white matter involvement. We report two subjects with WFS in which multifocal, progressive, and contrast-enhancing white matter abnormalities (WMA) led to the consideration of multiple sclerosis (MS). Methods: We retrospectively analyzed the clinical, genetic, and radiological data from two unrelated subjects with genetically confirmed WFS and multifocal WMA. Results: Subject I: a 43-year-old woman, heterozygous for a known WFS1 variant, had a history of congenital deafness and OA. The brain MRI documented progressive multifocal WMA including pericallosal lesions. Subject II: a 28-year-old woman, compound heterozygous for two WFS1 variants, was known for OA and diabetes mellitus. The brain MRI revealed multifocal periventricular, callosal, subcortical, and juxtacortical WMA, with some enhancing after gadolinium injection. Conclusions: Our report expands the WFS spectrum of white matter involvement to include progressive, seemingly inflammatory lesions. Although we cannot exclude a dual diagnosis, the roles of WFS1 and CISD2 in myelination suggest a selective white matter vulnerability in WFS.
P.095 Functional neuroimaging signatures associated with analgesic effects of neuromodulation for chronic pain and their value in predicting treatment outcome
Authors: Boone L , Noble T , El Helou A
Published: June 2023

Background: Responses to invasive neuromodulation therapy for chronic pain are highly variable after several months of sustained treatment, with some experiencing a complete loss of therapeutic effect. We sought to assess whether functional neuroimaging can provide a biomarker for treatment success and whether these biomarkers offer value in predicting treatment response. Methods: We searched Ovid MEDLINE and EMBASE from 1967 to 2022, including prospective studies correlating functional neuroimaging signatures with treatment response after surgical implantation. Results: After considering 355 studies for initial review, 22 studies were included. While there was significant heterogeneity in experimental design, preliminary findings suggest that differential regional cortical activation profiles and signatures can be employed to differentiate good from poor therapeutic responders. Three studies correlated pre-operative functional imaging with treatment effects post-implantation. For example, baseline activation patterns of specific brain regions on functional imaging modalities such as 11C-diprenorphrine PET and Tc-99m-SPECT significantly correlated with therapeutic response to motor cortex stimulation, and spinal cord stimulation (SCS), respectively. Conclusions: The included studies demonstrate the potential for functional imaging to predict the likelihood of successful neuromodulation treatment. The concept is relatively unexplored in the literature and could benefit from more studies with larger sample sizes to confirm clinical utility.
P.096 Effectiveness of palliative focal resective surgery in intracranial EEG confirmed multifocal intractable epilepsy in adult patients
Authors: Tamura G , Wiebe S , Josephson C , Salmon A , Singh S , Hader W
Published: June 2023

Background: Effectiveness of “palliative resections” of a dominant epileptogenic focus in adults with multifocal intractable epilepsy confirmed on intracranial EEG has rarely been reported. Methods: We retrospectively reviewed our database to identify patients who underwent focal resection after confirmation of multiple seizure foci on intracranial EEG. Results of presurgical investigations, intracranial EEG, procedures, complications and outcome were collected. Results: A total of 17 patients underwent palliative resection (8 left, 9 right). Preoperative MRI revealed malformations of cortical development in 6 patients, and MTS in 6 patients. Intracranial stereo EEG revealed 8 bilateral and 9 unilateral multifocal epileptogenic foci. Surgical procedures included anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy in 4 patients, ATL plus additional cortical resection in 7 patients, and extratemporal resection in 6 patients. One patient had dysphasia post ATL and a second patient had worsened cognitive dysfunction post extended frontal lobectomy. Favorable seizure outcome (Engel class I and II) was achieved in 10 patients (58.8%). Pathology revealed focal cortical dysplasia in 6 patients and hippocampal sclerosis in 5 patients. Conclusions: Palliative resection of a dominant epileptogenic focus confirmed by intracranial EEG is effective in carefully selected adult cases of intractable epilepsy, particularly in patients with lesional epilepsy.
P.098 Antibacterial envelopes prevent post-operative infections in neuromodulation surgery
Authors: Persad A , Ahmed S , Mercure-Cyr R , Waterhouse K , Vitali AM
Published: June 2023

Background: Neuromodulation unit placement can provide efficacious control of many neurological conditions. They are high risk for infection with a historic infection rate as high as 10%. Treatment of infection requires surgical removal and a long course of systemic antibiotics.  At our center, one surgeon uses antibacterial envelopes with all implanted neuromodulation devices. Methods: We conducted a retrospective cohort study of consecutive implantable pulse generator (IPG) and intrathecal pump unit implantation with an antibacterial envelope at our center. This cohort was then compared to a historical cohort of consecutive patients undergoing IPG or pump placement or revision prior to the use of the envelopes. Results: IPG: There were 18 (11.9%) class I infections in the pre-envelope cohort compared with 5 (2.1%) in the post-envelope cohort. The absolute risk reduction (ARR) with the use of antibacterial envelopes was 9.85% (95% confidence interval (CI) 4.3-15.4%, p<0.01).

Pump: There were 6 (14.6%) class I infections in the pre-envelope cohort compared with 1 (1.7%) in the post-envelope cohort. The ARR with the use of antibacterial envelopes was 12.9% (95% confidence interval 1.6-24.3, p<0.05). Conclusions: Based on our results, we recommend usage of antibacterial envelopes to reduce infection rates in neuromodulation surgery. Further study is needed.
P.111 5-ALA guided surgical resection of newly diagnosed high grade gliomas at Health Sciences North (HSN) in Sudbury, Ontario
Authors: Roach L , Chown A , McGregor S , Wolf A
Published: June 2023

Background: Since its approval by Health Canada in 2020, several neurosurgical centres across Canada have used 5-ALA, an oral drug that assists with surgical resection of malignant gliomas by causing tumour cells to fluoresce under the microscope. The study’s objective is to prospectively evaluate the extent of resection (EOR) and clinical outcomes in 5-ALA-guided surgery at HSN compared to historical controls. Methods: A retrospective analysis was performed of patients with malignant gliomas having undergone surgery at HSN from 2011 to December 2020, assessing the EOR (contrast-enhanced tumour on post-operative CT/MRI), progression-free survival (PFS), overall survival (OS). Results: 235 patients underwent surgery for malignant glioma including 51 newly-diagnosed patients felt to be surgically resectable and with post-operative imaging. 25/51 (49%) had no residual tumour. The median PFS and OS were 7.1 and 11.5 months respectively. To date, 3 patients have successfully undergone 5-ALA-guided surgery with complete resection of contrast-enhancing tumour and no new focal neurological deficit post-operatively. Conclusions: We continue to recruit and follow prospectively patients having undergone 5-ALA-guided resection of malignant gliomas at HSN. Patients living in Northern Ontario may derive significant benefits from the use of 5-ALA-guided surgery, particularly since other technologies, such as intraoperative MRI and ultrasound, are costly and not available.
P.112 Location pattern of recurrence of WHO Grade 1 Meningiomas
Authors: Ong K , Rizzuto M , Makarenko S
Published: June 2023

Background: Meningiomas can lead to significant morbidity and mortality and have recurrence potential despite their benign classification. The precise location of the recurrence has not been delineated. The objective of this study was to determine any spatial clustering of recurrence for surgically treated Grade 1 meningiomas. Methods: Patients diagnosed with Grade 1 meningiomas and treated with surgical resection with recurrence were reviewed. Patient demographics, presentation, extent of resection, time to recurrence, and location were established by medical records. Outcomes were the time to recurrence and location relative to the original surgical bed. Results: Among the 42 cases that met the study inclusion criteria, 12 were male and 30 were female. The mean age at treatment was 49.7 years, and the mean years until recurrence was 5.2 years. 33 (68.8%) tumours recurred locally, 12 (25.0%) recurred at the periphery (<1cm of the surgical bed), and 3 (6.3%) recurred distal to the resection site. Conclusions: A sizeable portion of cases may benefit from therapy directed beyond the resection margin. It may be more successful to prevent recurrence in these patients by performing a more aggressive resection of the dural attachment surrounding the tumour and/or focusing adjuvant therapy on the area surrounding the resection cavity.
P.114 When functional neuroimaging is ambiguous for language localization: a case for Wada testing
Authors: Zhou A , Hnenny L , Neudorf J , Kress S , Borowsky R , Gould L
Published: June 2023

Background: To localize cortical speech areas, methods such as fMRI are commonly used, but the Wada test can also determine whether a region is critical to the particular task. We report a case of a left-handed patient with a left frontal tumour in whom fMRI language paradigms produced both left and right Broca’s and Wernicke’s areas. Methods: All imaging used a 3 Tesla Siemens Skyra scanner. The patient performed five speech tasks: word reading, picture naming, semantic questions, pseudohomophone reading, and word generation. All preprocessing and statistical analyses for functional images were performed using Brain Voyager QX. Results: The fMRI results revealed right hemisphere dominance for language processing. A Wada test was performed in order to confirm whether the regions in the left hemisphere were critical to speech. The patient experienced speech arrest during the Wada test, thus confirming that despite bilateral speech activation, the left hemisphere speech regions are required for speech production. Conclusions: This case emphasizes the importance of preoperative fMRI in assessing the location of eloquent cortices adjacent to a tumour and the Wada test is still warranted for examining necessity of left hemisphere language regions when fMRI fails to show clear left-lateralization.
P.119 Quantification of the relationship between near infrared spectroscopy based and intracranial pressure based indices of cerebrovascular reactivity in moderate to severe TBI
Authors: Gomez A , Sainbhi AS , Froese L , Vakitbilir N , Stein K , Zeiler FA
Published: June 2023

Background: Cerebrovascular reactivity is an important contributor to secondary injury following traumatic brain injury (TBI). The poor spatial resolution and invasive nature of “Gold-standard” intracranial pressure (ICP) based indies of cerebrovascular reactivity limit their use. Near infrared spectroscopy (NIRS) based indices of cerebrovascular reactivity are minimally invasive and have improved spatial resolution. The precise relationship between NIRS and ICP based indices is quantified utilizing times series analysis and advanced statistical techniques. Methods: High-resolution physiologic data was collected in a cohort of adult moderate to severe TBI patients at a single quaternary care site. From this data both ICP and NIRS based indices of cerebrovascular reactivity were derived. The times series structure of these indices was determined and used to correct for autocorrelation in a linear mixed effects model of ICP based indices from NIRS based indices of cerebrovascular reactivity. Results: A total of 83 patients were included in this study. Times series analysis coupled with mixed effects modeling was utilized to examine the relationship between ICP and NIRS based indices of cerebrovascular reactivity. Conclusions: Times series analysis coupled with mixed effects modeling allows for a more complete understanding of the relationship between ICP and NIRS based indices of cerebrovascular reactivity in the setting TBI.
P.146 Anterior spinal cord herniation following an anterior cervical discectomy and fusion: case report
Authors: Elashaal AA , Elashaal Y
Published: June 2023

Background: Anterior cervical discectomy and fusion (ACDF) and corpectomy is one of the most common spinal operations performed worldwide to treat herniated discs causing anterior spinal cord compression , cervical spondylosis, fractures, and neoplasms, with the routine complications. There have been just a few known cases of anterior spinal cord herniation following multilevel anterior ACDF and corpectomy fusion cases. Methods: A 53-year-old male initially presented with a 3 year’s duration of increasing myelopathy with history of Anterior cervical surgery C3 -5. About 10 years prior he was not able to walk had difficulty to use his hand. (he have nice images on MRI scan of typical spinal herniation)Results: Patient was initially treated medically with utilizing analgesia and physiotherapy and gradually deteriorated over two year. Patient revision surgery and release of spinal cord with intra-operative durotomy and release of the spinal cord. He had only mild improvement in hand function, No change in legs function post operatively. Conclusions: The occurrence of spinal cord herniation through a prior ACDF or Corpectomy defect must be considered when patients present with recurrent myelopathy following anterior cervical surgery. Early investigation and early release surgery can improve the outcome for these group of patients
P.147 Exploring the bacterial hypothesis of low back pain: a prospective cohort study
Authors: MacLean MA , Julien L , Patriquin G , Leblanc J , Greene R , Alant J , Barry S , Glennie RA , Oxner W , Christie SD
Published: June 2023

Background: Occult bacterial infection is a proposed etiology of low back pain (LBP). However, a causative link between LBP and bacteria remains unconfirmed. Herein, we determined the incidence of occult discitis in patients receiving surgery for LDH. Methods: Study Design: prospective cohort study. Inclusion criteria: consecutive adult patients undergoing discectomy for symptomatic LDH. Exclusion criteria: prior epidural steroid use, prior spinal surgery, and antibiotic use within 2 weeks of surgery. Tissue samples: Four nuclear tissue and ligamentum flavum (control) samples were obtained per patient using stringent aseptic protocol. Samples underwent 16S-PCR and culturing. Results: Eighty-one patients were enrolled (mean age 43.3±13.3 years). All (100%) of tissue samples were negative by 16S PCR and no virulent species were detected. Nuclear and ligament cultures were both negative in 51 (62.9%) cases. Cultures were positive for nuclear tissue only, ligament only, or both in 14.8%, 12.3%, and 9.9% of cases, respectively. Fifteen of 20 (75%) disc positive samples grew a single colony of an indolent species. Conclusions: The findings of this prospective cohort study of consecutive patients receiving surgery for LDH do not support the theory of occult discitis. All samples were 16S-PCR negative, and most cultures were negative or grew a single colony suggestive of contamination.
GR.3 Socioeconomical disparities in acute ischemic stroke revascularization interventions in Ontario, Canada
Authors: Taghdiri F , Vyas MV , Kapral MK , Lapointe-Shaw L , Tse P , Porter J , Chen Y , Fang J , Yu AY
Published: June 2023

Background: Lower socioeconomic status is associated with worse outcomes after stroke. We evaluated the differences in acute revascularization treatments in patients with acute ischemic stroke (AIS) who were materially deprived compared to those who were not. Methods: In a population-based cohort study, we used linked administrative data to identify community-dwelling adults hospitalized for AIS between 2017-2022 in Ontario, Canada. The main exposure was neighborhood-level material deprivation quintiles. Multivariable logistic regression was used to obtain the adjusted odds ratio (aOR) of receiving revascularization treatments (thrombolysis or thrombectomy) for patients in each deprivation quintile compared to the least deprived quintile. Results: We identified 57,709 patients (median age 74 years; 45.9% female). Compared to patients in the least deprived quintile, those with higher deprivation were younger and more likely to have hypertension and diabetes, but less likely to have atrial fibrillation. Compared to patients in the least deprived quintile, fewer patients in the very deprived quintile (17.9% vs 19.6%, aOR 0.88, 95%CI [0.82,0.95]) and in the most deprived quintile (16.6% vs 19.6%, 0.77 [0.71,0.83]) received revascularization treatments. Conclusions: Our results suggest disparities in the use of acute ischemic stroke revascularization treatments by socioeconomic status despite access to universal health care.
GR.5 Incidence of orbital infarction syndrome following endovascular thrombectomy
Authors: MacMillan-Wang M , Shankar J , Alcock S , Trivedi A , Jain D
Published: June 2023

Background: Orbital infarction syndrome (OIS) is a rare entity defined as acute ischemia of intraorbital structures. Three case reports of OIS post-endovascular thrombectomy (EVT) have recently been published, two demonstrating absent choroid blush (CB) on digital subtraction angiogram (DSA). Our goals are to determine the true incidence of OIS post-EVT and to identify imaging findings (e.g. CB) that may alert neurologists to potential cases. Methods: A retrospective cohort study including all EVT patients from Health Sciences Center (HSC), Winnipeg in 2019-20 was performed. Patient charts were reviewed to determine the incidence of OIS. Pre- and post-EVT DSA images were reviewed, and the sensitivity and specificity of absent CB for OIS was calculated. Results: Out of 248 patients, 13 were excluded for incomplete charts, and 4 cases (1.7%) of OIS were discovered. During sensitivity/specificity analysis of absent CB for OIS, 51 patients were excluded for inadequate imaging. There were 4 true positives, 0 false-negatives, 113 true-negatives, and 67 false-positives; resulting in a sensitivity of 100% and worst-case scenario specificity of 63% (assuming all 51 indeterminate cases were false positives). Conclusions: OIS is rare post-EVT with an incidence of 1.7%. Absent CB is very sensitive for diagnosing OIS with lower specificity.
GR.7 Artificial intelligence-based decision support predicts requirement for neurosurgical intervention in acute traumatic brain injury
Authors: Malhotra AK , Smith C , Shakil H , Harrington EM , Ackery A , Nathens AB , Wilson JR , Colak E , Witiw CD
Published: June 2023

Background: We aimed to develop an efficient and reliable artificial intelligence solution to automate prediction of neurosurgical intervention using acute traumatic brain injury computed tomography (CT) scans. Methods: TBI patients were identified from 2005 - 2022 at a Level 1 Canadian trauma center. Model training, validation, and testing was performed using head CT scans with patient-level labels corresponding to whether the patient received neurosurgical intervention. The finalized model was then deployed in a simulated prospective fashion on all TBI patients presenting to our center over an 18-month epoch. Results: 2,806 TBI scans were utilized for development of the Automated Surgical Intervention Support Tool (ASIST-TBI). 612 additional consecutive scans were used for simulated prospective model deployment. Prediction of neurosurgical intervention exhibited an area under receiver operating curve (AUC) of 0.92, accuracy of 0.87, sensitivity of 0.87, and specificity of 0.88 on the test dataset. On simulated prospective data, the results were: AUC 0.89, sensitivity 0.85, specificity 0.84 and accuracy of 0.84. Conclusions: We demonstrate the development and validation of ASIST-TBI, a machine learning model that accurately predicts whether TBI patients will need neurosurgical intervention. This model has potential application to optimize decision support and province-wide efficiency of inter-facility TBI triage to tertiary care centers.
A.6 CSF1R-related adult-onset leukodystrophy with axonal spheroids and pigmented glia (ALSP) presenting as corticobasal syndrome (CBS): a case report and literature review
Authors: Leochico C , Espiritu A , Levitt S , Masellis M , Mitchell S
Published: June 2023

Background: Colony stimulating factor 1 receptor (CSF1R) mutations have various clinical, often overlapping, phenotypes. Methods: Case report and literature review. Results: We present a case of a previously independent 49-year-old woman with a 3-year history of early- and insidious-onset, rapidly progressive symptoms resembling CBS (parkinsonism, severe apraxia, global cognitive impairments, personality changes, depression, and functional decline). Brain MRI showed severe atrophy with frontoparietal predilection, asymmetric ex vacuo dilatation, atrophic corpus callosum, and patchy, asymmetric T2/FLAIR hyperintensities in the subcortical white matter. Spine MRI showed no cord signals. Brain MR spectroscopy revealed elevated choline with reduced N-acetyl-aspartate levels. The vasculitis screening, and leukodystrophy and CADASIL workups were all unremarkable. Finally, whole exome sequencing was done and a heterozygous variant of CSF1R (c.1735C>T, p.Arg579Trp) was found. Conclusions: Our patient’s novel CSF1R variant was found to be associated with ALSP. This report supports the utility of a comprehensive genetic testing in adult patients clinically presenting as CBS but with white matter abnormalities on T2-weighted MRI. Given that ALSP has several other clinical and radiologic mimickers, whole exome sequencing proves fundamental and can improve the diagnostic rates and understanding of ALSP. A well-informed diagnosis can lead to appropriate preventive genetic counseling to affected families.
D.3 Peripheral nerve injuries related to walking aid use: a systematic review
Authors: Manocha RH , Shank J , Ismaguilova A , Sigfusson M , Egbase A , Bartel K , Scholz N
Published: June 2023

Background: Walking aids such as crutches, canes and walkers are used by 2 million Canadians. Repetitive weight-bearing with walking aids may cause upper limb peripheral nerve injury. The objectives of this review were to: 1) identify types of nerve injuries reported with walking aids; 2) report electrodiagnostic findings; 3) identify typical treatment strategies; and 4) determine expected recovery time for such injuries. Methods: MEDLINE, EMBASE, CINAHL and Cochrane Library were searched for primary data in English published between 1950-2022. Abstracts were reviewed independently by 2 authors. Full-text reviews were independently conducted by 2 authors. Results: The search identified 3746 abstracts, 43 of which underwent full-text review. 31 studies were included. There were 144 cases of peripheral nerve injury. Crutches caused the most injuries (n=21 studies). The ulnar nerve was most commonly injured (n=27 cases). Improper walking aid fit was identified as a risk factor in 74% of cases. Stopping walking aid use was the most common treatment strategy (n=10 studies). Follow-up reports (n=20) indicated 65% of patients experienced recovery at 6 months. Conclusions: Improper walking aid fit and use were identified as major injury risk factors. A national program to teach patients and clinicians how to use walking aids may reduce injury risk.
E.3 Imaging of subdural hematoma
Authors: Devgan S , Shankar J
Published: June 2023

Background: Radiologic imaging has become integral in not only the detection and diagnosis of subdural hematoma, but also in guiding potential treatment options. Particularly, in the arena of chronic subdural hematoma, which has conventionally been managed via surgical drainage, although is shifting toward procedural intervention with embolization of the middle meningeal artery. This paper aims to review the imaging manifestations of subdural hematoma as a function of chronicity, standardized methods of measurement, and identifying the middle meningeal artery and its clinically significant variant anatomy as it pertains to embolization planning. Methods: A literature search using key terms and titles was conducted for articles containing imaging characteristics of subdural hematoma, approaches to measurement, and middle meningeal artery anatomy as the primary focus. Results: The expected evolution of subdural hematoma over time encompasses a broad array of imaging characteristics. Attempts at standardizing hematoma measurements include width, volume, and midline shift. Given the implication of the middle meningeal artery in potential therapeutic embolization, familiarity with its anatomy is vital not only for mapping access, but also for delineating possible dangerous collaterals. Conclusions: Equipped with a more comprehensive approach to characterizing subdural hematoma, the radiologist will be able to curate findings of greater utility to the clinician.
Brazen as Falstaff, Devious as Iago: Sir Ralph Lane's Approach to Holding Office in Ireland and Virginia
Authors: Rapple Rory
Published: June 2023

Much has been made of the ideological connection between the mental world of servitors in Elizabethan Ireland and the origins of early English colonial endeavor in North America. In this vein, the case of Sir Ralph Lane, the first governor of the Roanoke colony and, later, muster-master general of Ireland, would seem to present a historiographically promising test case, one that might not only link Ireland and the Roanoke Colony but also could show, following recent suggestions, how attitudinal, behavioral, and aspirational commonalities existed between early modern English military culture and the ethos of early English colonial endeavor. Lane's record on both sides of the Atlantic, however, rather than painting a picture of the applicability of martial virtue and military discipline at times of crisis, demonstrates instead the stark reality of the impulsive and appetitive culture of the garrison in the Elizabethan period and its corrosive effects. Lane's remarkable capacity for corruption, willful mismanagement, and wily self-defense in an Irish context in fact amplifies and complements troubling tendencies that scholars have recently detected in Lane's famous discourse of his government in what was commonly termed Virginia printed in Hakluyt's Principal Navigations. Lane can indeed serve as an emblem of common features shared by Elizabethan Englishmen drawn to office in Ireland and Elizabethan/Jacobean Englishmen drawn to settle in Virginia, but largely because of his mendacity, venality, and irresponsibility.
Whose Equality? Freedom of Religious Associations and Gaum v. Van Rensburg
Authors: de Freitas Shaun
Published: June 2023

In Gaum and Others v. Van Rensburg NO and Others, the South African High Court held the view that a decision taken by the Synod of the Dutch Reformed Church, which included a condition of a life of celibacy for gays and lesbians in order to be ordained as ministers in the church, along with a prohibition against the solemnizing of same-sex civil unions by ministers in the church, resulted in a violation of the right to equality and that unfair discrimination based on sexual orientation had taken place. Consequently, the finding in Gaum postulated a specific view on the permissible boundaries regarding conduct related to sexual orientation that should apply to a religious association. In this regard, Gaum is of concern when considering that courts in democracies around the world generally refrain from getting involved in matters related to the central doctrines of a religious association. Gaum’s findings are disquieting not only for the effective protection of the right to freedom of religion (in both an individual and associational context) but also for the furtherance of diversity. It is argued in this article that Gaum exceeded its jurisdiction in adjudicating on matters related to conduct regarding sexual orientation, an argument that critically focuses on the concept of equality against the background of the importance of the protection of the autonomy of religious associations.
Moderate deviations inequalities for Gaussian process regression
Authors: Li Jialin , Ryzhov Ilya O.
Published: June 2023

Gaussian process regression is widely used to model an unknown function on a continuous domain by interpolating a discrete set of observed design points. We develop a theoretical framework for proving new moderate deviations inequalities on different types of error probabilities that arise in GP regression. Two specific examples of broad interest are the probability of falsely ordering pairs of points (incorrectly estimating one point as being better than another) and the tail probability of the estimation error at an arbitrary point. Our inequalities connect these probabilities to the mesh norm, which measures how well the design points fill the space.
Beyond the Gonzalo Mystique: Challenges to Abimael Guzmán’s Leadership inside Peru’s Shining Path, 1982–1992
Authors: La Serna Miguel , Starn Orin
Published: June 2023

From the moment it launched its armed insurgency in 1980 until the death of its former leader in September 2021, Peru’s Shining Path mesmerized observers. The Maoist group had a well-established reputation as a personality cult whose members were fanatically devoted to Abimael Guzmán, the messianic leader they revered as “Presidente Gonzalo.” According to this narrative, referred to here as the “Gonzalo mystique,” Shining Path zealots were prepared to submit to Guzmán’s authority and will—no matter how violent or suicidal—because they viewed him as a messiah-prophet who would usher in a new era of communist utopia. Drawing on newly available sources, including the minutes of Shining Path’s 1988–1989 congress, this article complicates the Gonzalo mystique narrative, tracing the unrelenting efforts by middle- and high-ranking militants to challenge, undermine, disobey, and even unseat Guzmán throughout the insurgency. Far from seeing their leader as the undisputed cosmocrat of the popular imagination, these militants recognized Guzmán for who he was: a deeply flawed man with errant ideas, including a dubious interpretation of Maoism, problematic military strategy, and a revolutionary path that was anything but shining.
I Come before You a Changed Man: “Insight,” Compliance, and Refurbishing Penal Practice in California
Authors: Dalke Isaac
Published: June 2023

In 2008 the California Supreme Court forced the state’s parole board to change how it justifies the decision to keep a person in prison. This article combines computational and interpretive analysis of 9,842 hearing transcripts to show how, to achieve compliance with the court, parole board commissioners refurbished an old rehabilitative way of talking about incarceration found in a set of secondary hearing procedures and placed it at the center of decisions. The article considers the consequences of this shift for inequality in incarceration in California. More broadly, it makes the case for focusing on the relationship between administrators and those who can directly intervene in their practices in the name of compliance to understand bureaucratic penal change.
The Reception of Relativity in American Philosophy
Authors: Verhaegh Sander
Published: June 2023

Historians have shown that philosophical discussions about the implications of relativity significantly shaped the development of European philosophy of science in the 1920s. Yet little is known about American debates from this period. This article maps the first responses to Einstein’s theory in three U.S. philosophy journals and situates these papers within the local intellectual landscape. I argue that these discussions (1) stimulated the development of a distinctly American branch of philosophy of science and (2) paved the way for the logical empiricists who emigrated to the United States in the years before World War II.
Roman-era alluvial waste in the Vistre de la Fontaine (Nîmes, southeast France): from a sacred spring to a contaminated river
Authors: Flaux Clément , Save Sabrina , Scrinzi Maxime , Minvielle Larousse Nicolas , Vaschalde Christophe , Renaud Audrey , Tillier Margaux , Guihou Abel , Deschamps Pierre , Véron Alain
Published: June 2023

The excavation of a palaeochannel at the Vistre de la Fontaine 2-2 archaeological site, 3 km downstream from the ancient city of Nîmes (southeastern France), provided an accumulation sequence covering the last 2,500 years. Trace metal analyses of these alluvial sediments disclosed lead (Pb) contamination during the Early Roman Empire, with concentrations close to 1,000 ppm, a factor of 100 above the local geochemical background. This excess of Pb shows a uniform isotopic signature that may reflect unchanged ore sources, perhaps from the Massif Central or from Great Britain. The Pb peak accompanied visible waste that was transported in the sediments of the Vistre de la Fontaine at the time of the development of the Nîmes urban water supply and drainage network during the Early Roman Empire. This research shows the bimillennial persistence of palaeo-contamination in a peri-urban alluvial plain and the relevance of fluvial sedimentary archives in documenting ancient waste.
COUETTE FLOW OVER A HEAT ISLAND
Authors: FORBES LAWRENCE K. , WALTERS STEPHEN J.
Published: June 2023

A viscous fluid is confined between two smooth horizontal walls, in a vertical channel. The upper wall may move with constant speed, but the lower wall is stationary and a portion of it is heated. A plume of heated fluid develops, and may also be swept downstream by the motion of the upper wall. When the heating effect is small and the upper plate does not move, a closed-form solution for the temperature profile is presented. A numerical spectral method is then presented, and allows highly accurate nonlinear solutions to be obtained, for the temperature and the fluid motion. These are compared against the closed-form solution in the linearized case, and the effects of nonlinearity on temperature and velocity are revealed. The results also show that periodic plume shedding from the heated region can occur in the nonlinear case.
The Garden of Forking Paths; An Evaluation of Joseph’s ‘A Reevaluation of the 1990 “Minnesota Study of Twins Reared Apart” IQ Study’
Authors: Bouchard Thomas J.
Published: June 2023

Joseph has written what purports to be a refutation of studies of Twins Reared-Apart (TRAs) with a singular focus on the Minnesota Study of Twins Reared-Apart (MISTRA). I show, in detail, that (a) his criticisms of previous TRA studies depend on sources that were discredited prior to MISTRA, as they all failed the test of replicability, (b) the list of biases he uses to invalidate MISTRA do not support his arguments, (c) the accusations of questionable research practices are unsubstantiated, (d) his claim that MISTRA should be evaluated in the context of psychology’s replication crisis is refuted. The TRA studies are constructive replications. Like many other scholars, past and present, he has been misled by the variation introduced by small samples (sampling error) and the distortion created by walking in the garden of forking paths. His endeavor is a concatenation of elision and erroneous statistical/scientific reasoning.