bluuebunny/crossref_metadata_2025 huggingface dataset:
China in Twentieth- and Twenty-First-Century African Literature
Authors: Yoon Duncan M.
Published: June 2023

China in Twentieth- and Twenty-First Century African Literature unpacks the long-standing complexity of exchanges between Africans and Chinese as far back as the Cold War and beyond. This scope encompasses how China, which emerged as a main engine of the world economy by the end of the twentieth century, has transformed patterns of globalization across the continent. In this ground-breaking work on cultural representations, Duncan M. Yoon examines the controversial symbol of China in African literature. He reads acclaimed authors like Kofi Awoonor, Henri Lopes, and Bessie Head, as well as contemporary writers, including Ufrieda Ho, Kwei Quartey, and Yvonne Adhiambo Owuor. Each chapter focuses on a genre such as poetry, detective fiction, memoir, and the novel, drawing out themes like resource extraction, diaspora, gender, and race. Yoon demonstrates how African creative voices grapple with and make meaning out of the possibilities and limitations of globalization in an increasingly multipolar world.
Beyond Buzzwords: Mandatory Human Rights Due Diligence and a Rights-Based Approach to Business Models
Authors: Leite Marianna
Published: June 2023

This article argues that the trend to zoom into mandatory human rights due diligence (mHRDD) as the sole solution to corporate abuse is misleading. In fact, it might risk missing entirely the main point which, as set out in this article, should be creating economic systems that enable rights-based and rights-driven business models. A small, but growing number of scholarly articles address the economic, fiscal and regulatory institutions needed to create an enabling environment for the fulfilment of human rights. These policy areas constitute what some of us understand as a ‘rights-based economy’ or ‘rights-enabling economies’. State-level efforts would be much more effective in promoting substantive equality if driven by a rights-based approach rather than a market logic. This article contends that while ensuring comprehensive mHRDD is in place as a preventative and mitigation tool, states must also push for transformative macroeconomic policies based on human rights principles as a way to fundamentally change business models.
F.3 Comprehensive multiplatform analysis of CDKN2A alterations in meningiomas
Authors: Wang JZ , Patil V , Liu J , Dogan H , Tabatabai G , Behling F , Hoffman E , Bunda S , Yakubov R , Kaloti R , Brandner S , Gao A , Cohen-Gadol A , Barnholtz-Sloan J , Skardelly M , Tatagiba M , Raleigh D , Sahm F , Boutros PC , Aldape K , Nassiri F , Zadeh G
Published: June 2023

Background: In meningiomas, CDKN2A/B deletions are associated with poor outcomes but are rare in most cohorts (1-5%). Large molecular datasets are therefore required to explore these deletions and their relationship to other prognostic CDKN2A alterations. Methods: We utilized multidimensional molecular data of 560 meningiomas from 5 independent cohorts to comprehensively interrogate the spectrum of CDKN2A alterations through DNA methylation, copy number variation, transcriptomics, and proteomics using an integrated molecular approach. Results: Meningiomas with either CDKN2A/B deletions (partial or homozygous loss) or an intact CDKN2A gene locus but elevated mRNA expression (CDKN2Ahigh) both had poor clinical outcomes. Increased CDKN2A mRNA expression was a poor prognostic factor independent of CDKN2A deletion. CDKN2A expression and p16 protein increased with tumor grade and more aggressive molecular and methylation groups. CDKN2Ahigh meningiomas and meningiomas with CDKN2A deletions were enriched for similar cell cycling pathways dysregulated at different checkpoints. p16 immunohistochemistry was unreliable in differentiating between meningiomas with and without CDKN2A deletions, but increased positivity was associated with increased mRNA expression. CDKN2Ahigh meningiomas were associated with gene hypermethylation, Rb-deficiency, and lack of response to CDK inhibition. Conclusions: These findings support the role of CDKN2A mRNA expression as a biomarker of clinically aggressive meningiomas with potential therapeutic implications.
P.004 Comparison of the Montreal Cognitive Assessment (MoCA) and Rowland Universal Dementia Assessment Scale (RUDAS) for identification of mild cognitive impairment and dementia
Authors: Lam K , Wang M , Smith E , Ismail Z , Ganesh A
Published: June 2023

Background: There are many cognitive tests that detect mild cognitive impairment (MCI) and dementia such as the Montreal Cognitive Assessment (MoCA) and Rowland Universal Dementia Assessment Scale (RUDAS). The comparative performance of these screening tests for identifying MCI and dementia is unknown. Methods: The MoCA and RUDAS were administered during baseline visits for patients in the Calgary Neurosciences Program. Those that enrolled in the Prospective Registry of Persons with Memory Symptoms (PROMPT) had their scores related to their final clinical diagnosis. Cut-off scores of 26 for the MoCA and 22 for the RUDAS were used to indicate a positive result. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of both cognitive scores were compared. Results: The sensitivity, specificity, PPV, NPV, and accuracy of the MoCA (n = 125) was 89.3%, 72.7%, 93.9%, 59.3%, and 86.4%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of the RUDAS (n = 125) was 47.6%, 100%, 100%, 29.0%, 56.8%, respectively. Conclusions: In patients with cognitive complaints presenting to a specialist clinic, the MoCA was more sensitive and accurate than the RUDAS for a final clinician diagnosis of mild cognitive impairment or dementia when using the standard cut-offs.
P.007 Web-based monitoring for cognitive decline following deep brain stimulation
Authors: Howard CW , Fox MD
Published: June 2023

Background: There is a pressing need to monitor the cognitive outcomes of patients undergoing deep brain stimulation (DBS) for movement disorders, despite the prevalence of pre-operative cognitive evaluations. Previous research has demonstrated the potential for DBS to induce reversible cognitive decline, highlighting the need for post-operative cognitive monitoring. Methods: To address this issue, the present study sought to improve upon the existing Autonomous Cognitive Examination through the development of a 5-minute web-based exam. This examination leverages the capacity of machine-learning algorithms to evaluate complex multimodal inputs, including cognitive and movement disorders, and is made available through a web-based platform for physicians to administer to their patients. Results: The outcome of this study was the development of a cognitive evaluation platform, which enables physicians to administer and view results of a brief cognitive examination with sensitivity to multiple domains of cognition, including movement disorders. The web-application based screening examination is easily accessible and can be used on any device. Conclusions: This web-based cognitive examination offers a crucial solution for monitoring longitudinal cognition in high-risk patient populations undergoing DBS for movement disorders. Its ability to assess complex multimodal inputs has broad applications beyond movement disorders and serves as a valuable tool for detecting cognitive decline.
P.009 Comparison of Montreal Cognitive Assessment (MoCA) and Rowland Universal Dementia Assessment Scale (RUDAS) scores in diverse populations
Authors: Lam K , Wang M , Smith E , Ismail Z , Ganesh A
Published: June 2023

Background: The Montreal Cognitive Assessment (MoCA) and Rowland Universal Dementia Assessment Scale (RUDAS) are tests used to detect mild cognitive impairment (MCI) and dementia. However, it has been suggested that the MoCA may not be appropriate for diverse populations, and that the relatively newer RUDAS may be better suited as a universal cognitive test. Methods: The MoCA and RUDAS were administered at baseline visits for participants enrolled in the Prospective Registry of Persons with Memory Symptoms (PROMPT). Test scores were compared for patients with different levels of educational attainment, first language, and race using the Kruskal-Wallis test. Results: The difference in MoCA (0.029) and RUDAS (0.0041) scores between patients with different levels of educational attainment (n = 141) was significant. The difference in MoCA (0.62) and RUDAS (0.78) scores between patients with a different first language (n = 141) was not significant. The difference in MoCA (0.64) and RUDAS (0.96) scores between patients of different race (n = 141) was not significant. Conclusions: The difference between MoCA and RUDAS scores remained consistent regardless of level of educational attainment, first language and race. The results suggest that the RUDAS may not be more appropriate than the MoCA in detecting MCI and dementia across diverse populations.
P.10 Adding a neuroimaging safety net to the work up of status epilepticus at the Ottawa Hospital
Authors: Gotfrit R , Zwicker J , Stotts G , Fantaneanu T , Aviv RI , Dowlatshahi D
Published: June 2023

Background: CT angiogram of the head and neck (CTA) is not part of the routine work-up of status epilepticus (SE), which could miss acute ischemic stroke (AIS) as the cause. We hypothesized that healthcare savings from early treatment of otherwise undiagnosed AIS would be greater than the cost of adding a routine CTA for work-up of SE (all comers). Methods: The total number of patients presenting to ER with SE (defined as seizure/epilepsy+hospital admission), and the subgroup who were diagnosed with a new ischemic stroke, or received a CTA were retrospectively calculated at the Ottawa Hospital between 2010-2019. CTA costs, and savings of early treatment of AIS were obtained from the Department of Radiology and literature review, respectively. Results: 727 individuals presented with SE. 3% (n=22) had a new ischemic stroke-of these, 95% (n=21) did not receive a CTA (considered missed AIS). Assuming CTA could help detect every case of ischemic stroke missed this could result in 2.27 additional strokes caught early/year, and assuming if all thrombolysis candidates this would net cost $7,967/year (vs no acute treatment), or if all thrombolysis+thrombectomy candidates would net save $19,823/year (vs thrombolysis alone). Conclusions: Routine CTA in SE in the ER has potential to result in healthcare savings.
P.013 Patient preferences for selection of preventive migraine therapies in Canada: results from a discrete choice experiment
Authors: Bougie JK , Ladouceur M , Martin A , Beusterien K
Published: June 2023

Background: This study assessed the importance of mode of administration relative to other treatment attributes when selecting a preventive migraine therapy. Methods: Cross-sectional study among Canadian adults diagnosed with migraine with ≥5 monthly migraine days and tried ≥2 prescription migraine treatments (any kind/duration). Preferences for treatments varying in the following attributes were evaluated via a discrete choice experiment: speed of efficacy (effective in 24hr/1wk/3mo), duration of efficacy (wears off never/1wk/2 wks before next dose), mode of administration (infusion/auto-injection/cranial injections), administration setting (clinic/home), and administration frequency (1mo/3mo). Attribute-level preference weights were estimated using Hierarchical Bayes modeling. Results: Of 200 respondents, 142 experienced episodic migraine and 58 experienced chronic migraine. Preference weights confirmed that respondents’ most preferred treatments were those that provided fast and long-lasting efficacy (effective in 24hr = 0.59; wears off never = 1.07) and were offered via infusion (0.58) or auto-injection (0.47) over intracranial injection (-1.04). Respondents reported being moderately willing to receive infusions in either a home or clinic setting (1-6 Likert scale from “not at all” to extremely” willing). Conclusions: Second to speed and duration of efficacy, respondents were most concerned with mode of administration when selecting their preferred migraine preventive, suggesting that physicians should consider patient preferences in treatment decision-making.
P.018 Oculomotor learning as a biomarker in Huntington’s Disease (HD) patients
Authors: Déziel A , Pinotti A , Richard A
Published: June 2023

Background: Huntington’s disease (HD) is an inherited neurodegenerative disorder associated with cognitive, psychiatric, and motor dysfunction. As a potential behavioural biomarker, experimental tasks assessing motor learning may thus provide a reasonable assay of HD onset and progression. The saccadic adaptation paradigm is a non-invasive, accessible method of assessing rapid learning in the oculomotor system. Evidence demonstrates that the thalamus and basal ganglia are important loci for saccadic adaptation, also known to exhibit neurodegenerative pathology before the onset of clinically observable symptoms in HD. Methods: 26 early symptomatic HD patients (Total Functional Capacity Score ≥ 10/13) and sex/age-matched controls were tested on a standard saccadic adaptation task. Eye movements were measured using infrared oculography. Learning dynamics of how quickly the participants adapted their saccade metrics were analysed using state learning models. Results: Initial findings demonstrate that the learning dynamics of HD patients are slower and more variable with respect to saccade amplitude compared to controls. Conclusions: These results demonstrate that motor learning dynamics as captured by a saccadic adaptation task reveal early motor dysfunction in HD, thus providing a discriminating tool to detect early pathological changes in HD patients. Further work is needed regarding applications as a biomarker for disease progression.
P.020 Advanced care team for Parkinson’s: a novel approach for patients and carepartners in advanced parkinsonism
Authors: Cantu Flores K , Achen B , Alizadeh P , McRae E , Liam M , Toews K , Kline R , Bruno V
Published: June 2023

Background: People with parkinsonian syndromes (PPS) in advanced stages deal with a wide range of highly impactful motor and non-motor problems, including dementia, hallucinations, falls, and dysautonomia. Care planning becomes difficult and unpredictable. In addition, while healthcare providers focus on reducing symptom burden, PPS and carepartners deal with difficult emotions such as demoralization and grief. At those stages, multidisciplinary care becomes imperative. In October 2022 we launched Advanced Care Team for Parkinson’s (ACT-PD), a clinical research program whose goals include advanced care planning, symptoms management and emotional support. Methods: Our primary outcomes are changes in quality of life (QoL-AD), carepartner burden (ZBI-12) and patient satisfaction. The team involves neurology, palliative nursing, social-work, psychology, and spiritual care. Every three months, participants meet the team in person or virtually. In two hours, they address tailored concerns, complemented with phone calls as required. Accordingly, participants complete assessments. Results: In its first 4 months, ACT-PD included 40 PPS and 40 carepartners. Preliminary results show that the first visit with ACT-PD resulted in a 30% reduction in carepartner burden and 28% of improvement in patients’ QoL. Conclusions: Even in early phases, this novel patient and carepartner-centered approach improves QoL and reduces carepartner burden in PPS in advanced disease stages.
P.024 Pain in monogenic Parkinson’s Disease
Authors: Alizadeh P , Terroba Chambi C , Achen B , Cantu Flores K , Bruno V
Published: June 2023

Background: Pain is one of the most bothersome symptoms reported in Parkinson’s disease (PD), yet its underlying pathophysiological mechanisms are not well understood. Its prevalence and effects on quality of life in patients with monogenic forms of PD have not been systematically explored. Methods: Comprehensive literature review exploring the association between monogenic forms of PD (SNCA, PRKN, PINK1, DJ1, and LRRK2) and pain. We included pain in ATP13A2, VPS35, and GBA1 mutation carriers. After initial screening, sixty-five relevant articles were identified. Studies’ design, sample sizes, and pain outcome measures were highly heterogeneous. Results: Our review suggests that patients with some PD monogenic causes show a higher prevalence of specific pain subtypes. While painful foot dystonia is more frequently reported in SNCA and PRKN carriers, the last ones also describe frequent lower back pain mostly. Pain in general is most commonly reported in PINK1 mutation carriers followed by patients with LRRK2 mutations. Pain as an initial symptom and severe symptom is well described in GBA1-PD patients. There is limited and insufficient evidence to report on pain and ATP13A2, DJ1, and VPS35 mutations. Conclusions: Linking genetic profiles to pain outcomes may have a meaningful clinical impact, facilitating individualized treatment for pain in PD.
P.033 COVID-19: neurologic and cardiac complications among Chinese and South Asians in Ontario: waves 1-3
Authors: Chu JY , Moe GW , Vyas MV , Chen R , Chow C , Gupta M , Ko DT , Koh M , Liu PP
Published: June 2023

Background: This is a population-based retrospective study of neurologic and cardiac complications of COVID-19 among Chinese and South Asians in Ontario during waves 1-3. Methods: Chinese and South Asians with COVID-19 were identified using a validated surname algorithm and their outcomes of mortality, and cardiac and neurologic complications with those of the general population using multivariable logistic regression models. Results: Compared to the general population (n= 439,977), the Chinese population (n= 15,208) was older (mean age 44.2 vs 40.6 years, P < 0.001) and the South Asian population (n= 46,333) was younger (39.2 years, P < 0.001). The Chinese population had a higher 30-day mortality (odds ratio [OR] 1.44; 1.28-1.61) and more hospitalization or emergency department visits(OR 1.14; 1.09-1.28), with a trend toward a higher incidence of cardiac complications (OR 1.03; 0.87-1.12) and neurologiccomplications (OR 1.23; 0.96-1.58). South Asians had a lower 30-day mortality (OR 0.88; 0.78-0.98) but a higher incidence of hospitalization or emergency department visits (OR 1.17; 1.14-1.20) with a trend toward a lower incidence of cardiac complications(OR 0.76; 0.67-0.87) and neurologic complications (OR 0.89; 0.73-1.09). Conclusions: Ethnicity continues to be an important determinant of mortality, cardiac and neurologic outcomes, and healthcare use among Ontario patients with COVID-19.
P.040 Long-term efficacy and safety of ravulizumab in adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis
Authors: Vu T , Meisel A , Mantegazza R , Annane D , Katsuno M , Aguzzi R , Rampal N , Howard JF
Published: June 2023

Background: The 26-week double-blind, randomized, placebo-controlled period (RCP) of the CHAMPION MG study (NCT03920293) demonstrated ravulizumab’s efficacy and tolerability in anti-acetylcholine receptor antibody-positive (AChR Ab+) generalized myasthenia gravis (gMG). Methods: In the ongoing open-label extension (OLE), patients receive intravenous ravulizumab (blind loading dose in placebo-treated patients or bridging dose in ravulizumab-treated patients, then 3000–3600 mg according to body weight every 8 weeks) for ≤4 years. Data from RCP baseline up to Week 60 were analyzed. Results: Ravulizumab’s long-term efficacy (n=161) and safety (n=169) were assessed. Patients who switched from placebo in the RCP to ravulizumab in the OLE (n=83) showed rapid improvement (least squares mean, 95%CI) in Myasthenia Gravis-Activity of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) total scores, which were maintained through 34 weeks (MG-ADL: −1.7, −2.7 to −0.8; QMG: −3.1, −4.2 to −1.9). Improvements achieved by ravulizumab-treated patients (n=78) in the RCP were sustained through 60 weeks (MG-ADL: −4.0, −4.8 to −3.1; QMG: −4.1, −5.4 to −2.9). Ravulizumab was well tolerated; no meningococcal infections were reported. Four deaths unrelated to study treatment occurred. Conclusions: Ravulizumab demonstrated sustained improvements in MG symptoms and was well tolerated for up to 60 weeks in adults with AChR Ab+ gMG.
P.044 Efficacy, safety, and tolerability of efgartigimod in AChR-Ab– patients with Generalized Myasthenia Gravis: interim analysis of ADAPT/ADAPT+
Authors: Bril V , Vu T , Karam C , Peric S , De Bleecker JL , Murai H , Pasnoor M , Saccà F , Meisel A , T’joen C , Utsugisawa K , Mantegazza R , Howard JF
Published: June 2023

Background: Efgartigimod, a human IgG1 antibody Fc-fragment, reduces IgG levels through neonatal Fc receptor blockade. Patients with anti-acetylcholine receptor antibody–negative (AChR-Ab–) generalized myasthenia gravis (gMG) comprise 15%-20% of the gMG population and have limited approved treatment options. We evaluated long-term safety and efficacy of efgartigimod in AChR-Ab– patients from ADAPT/ADAPT+ (open-label extension). Methods: ADAPT evaluated safety and efficacy of efgartigimod versus placebo in AChR-Ab+ (n=129) and Ab– (n=38) patients with gMG. This integrated analysis includes 37 AChR-Ab– patients who received ≥1 dose of efgartigimod in ADAPT/ADAPT+ through October 2020 (median[range] follow-up: 453[85-721] days). Responder status was defined as ≥2-point (MG-ADL) and ≥3-point (QMG) improvement for ≥4 consecutive weeks (with first improvement 1 week after last infusion). Results: Among AChR-Ab– patients in ADAPT (cycle 1), 68.4% (13/19) efgartigimod-treated were MG-ADL responders (placebo, 63.2% [12/19]), and 52.6% (10/19) were QMG responders (placebo, 36.8% [7/19]). In the integrated ADAPT/ADAPT+ analysis (cycle 1), AChR-Ab– patients improved from baseline in MG-ADL/QMG scores, with consistent improvements across multiple subsequent cycles. No clinically meaningful differences in safety or efficacy outcomes between AChR-Ab+ and Ab– patients occurred. Conclusions: Long-term treatment (median >1 year) with efgartigimod was well tolerated and associated with clinically meaningful improvements in MG-ADL/QMG scores in AChR-Ab– patients.
P.074 Risk factors for perinatal arterial ischemic stroke (PAIS): A machine learning approach
Authors: Srivastava R , Cole L , Forkert ND , Dunbar M , Shevell M , Oskoui M , Basu A , Rivkin M , Shany E , de Vries LS , Dewey D , Letourneau N , Hill MD , Kirton A
Published: June 2023

Background: Perinatal arterial ischemic stroke (PAIS) is a leading cause of hemiparetic cerebral palsy. Multiple risk factors are associated with PAIS but studies are limited by small sample sizes and complex interactions. Unbiased machine learning applied to larger datasets may enable the development of robust predictive models. We aimed to use machine learning to identify risk factors predictive of PAIS and compare these to the existing literature. Methods: Common data elements of maternal, delivery, and neonatal factors were collected from three perinatal stroke registries and one control sample over a 7-year period. Inclusion criteria were MRI-confirmed PAIS, term birth, and idiopathic etiology. Random forest machine learning in combination with feature selection was used to develop a predictive model of PAIS. Results: Total of 2571 neonates were included (527 cases, 2044 controls). Risk factors uniquely identified through machine learning were infertility, miscarriage, primigravida, and meconium. When compared, factors identified through both literature-based selection and machine learning included maternal age, fetal tobacco exposure, intrapartum fever, and low 5-minute APGAR. Conclusions: Machine learning offers a novel, less biased method to identify PAIS predictors and complex pathophysiology. Our findings support known associations with concepts of placental disease and difficult fetal transition and may support early screening for PAIS.
P.075 Pediatric intracranial tuberculoma: case report and review of literature
Authors: Liu E , Kakodkar P , Pan H , Zhou A , Wan C , Auer RN , Sanche S , Vitali A , Radic J
Published: June 2023

Background: Tuberculosis is an airborne disease caused by Mycobacterium Tuberculosis. Intracranial tuberculoma is a rare complication of extrapulmonary tuberculosis due to hematogenous spread to subpial and subependymal regions. Intracranial tuberculoma can occur with or without meningitis. Methods: A 3-year-old male who recently emigrated from Sudan presented to the emergency department with right-sided seizures lasting 30 minutes which were aborted with levetiracetam and midazolam. CT head revealed a multilobulated left supratentorial mass, with solid and cystic components measuring 8.0 x 4.8 x 6.5 cm. The patient had successful surgical resection of the mass which was positive for Mycobacterium Tuberculosis. He was started on rifampin, isoniazid, pyrazinamide, ethambutol, and fluoroquinolone and discharged home in stable condition. Results: Literature review on pediatric intracranial tuberculoma was performed which included 48 studies (n=49). The mean age was 8.8 ± 5.4 years with slight female predilection (59%). Predominant solitary tuberculomas (63%) were preferentially managed with both surgical resection and antitubercular therapy (ATT) compared to multifocal tuberculomas that were preferentially managed with ATT. Conclusions: Intracranial tuberculoma is a rare but treatable cause of space-occupying lesions in children. Clinicians should maintain high-level of suspicion in patients from endemic regions and involve infectious disease service early in patient’s care.
P.085 The effect of remote ischemic conditioning on cognitive and radiological outcomes in cerebrovascular diseases: a systematic review
Authors: Rosentreter R , Betzner W , Guild K , Ganesh A
Published: June 2023

Background: The effect of remote ischemic conditioning on cognitive and radiological outcomes in patients with cerebrovascular disease is uncertain. We performed a systematic review to evaluate the effects of remote ischemic conditioning on cognitive and radiological outcomes in patients with cerebrovascular diseases. Methods: A systematic search using relevant keywords and database specific terms was conducted in MEDLINE, Embase, and Web of Science from inception to October 27 2022. Results: A total of 4269 articles were screened, of which 20 were included. Ten papers assessing cognitive outcomes were included, with 5/10 reporting improvements in cognitive scores relative to a control group. Sixteen papers reporting on radiologic outcomes were included, three reporting on changes in infarct volume, and four on lesion volume. Improvement in infarct and lesion volume was reported in 1/3 studies and 4/4 studies respectively, however there was considerable variation in the time between assessments (range 1-365 days). Nine papers assessing blood flow changes were found, of which 3/8 using transcranial doppler reported improved blood flow velocity post intervention. Conclusions: The articles identified suggest that remote ischemic conditioning may provide improvement for both cognitive and radiological outcomes in patients with cerebrovascular diseases, however future well-designed studies are needed to determine degree of benefit.
P.088 Computed tomography angiography for diagnosis of brain death; a technical review
Authors: Aziz Rizk A , Shankar JJ
Published: June 2023

Background: Brain death is defined as an irreversible cessation of all brain activity. Ancillary tests are an objective way to support an initial diagnosis of brain death. Computed tomography angiography (CTA) is an imaging modality utilized as an ancillary mean to assist clinicians with such diagnosis. Different criteria and scoring systems have been proposed, however clear criteria are yet to be recognized to demonstrate full brain circulatory arrest. We aim to discuss different scoring systems presented in the literature and make evidence-based recommendations. Methods: A literature search using titles and key terms was conducted for articles containing brain death ancillary testing diagnosis, and CTA as primary focus. Results: CTA has the benefits of being non-invasive, fast, readily and widely available and it is especially useful in unstable patients. It is essential, however, to confirm intravascular injection of contrast injection by checking opacification of External Carotid Artery branches on CTA to prevent false diagnoses. Conclusions: When faced with the challenging decision to declare brain death in a patient, radiologists often face great apprehension and concern for the large responsibility bestowed upon them. It is critical for radiologist to understand that the final diagnosis of brain death is based on clinical criteria.
P.097 Effect of stimulation site on brain network activity and phonemic verbal fluency: an fMRI study.
Authors: Santyr B , Cohn M , Germann J , Ajala A , Qiu J , Boutet A , Lozano A
Published: June 2023

Background: In Parkinson’s disease, deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidus internus (GPi) produces comparable motor benefits. Although both increases the risk of cognition and verbal fluency (VF) decline, the risk is greater following STN-DBS. The consequences of stimulating these different sites on brain network activity is unknown. We use functional magnetic resonance imaging (fMRI) during in vivo stimulation to investigate differences between STN-DBS and GPi-DBS and correlate with change in VF. Methods: Left-sided, stimulation-cycling block-design fMRI was acquired at 3-Tesla in 51 STN-DBS and 15 GPi-DBS following routine clinical programming. Blood oxygen level-dependent (BOLD) response to stimulation was compared between groups. Phonemic VF was assessed pre- and postoperatively. Results: Voxel-wise t-test between STN-DBS and GPi-DBS BOLD response maps revealed areas of significant difference (p<0.001) in the left frontal operculum and the left caudate head. Stimulation BOLD response appears to show slight inverse correlation with postoperative VF decline. The trend is reversed at the left frontal operculum in STN-DBS compared to GPi-DBS. Conclusions: Decline in VF in PD-DBS seems associated with the stimulation BOLD response at the left frontal operculum and the left caudate head. The effect differs depending on stimulation site, suggesting differing effects on brain network activity.
P.126 Prediction of cerebral vasospasm using radiographical and clinical features: a machine learning model
Authors: Hsu J , Churchill I , Holden M , Lesiuk H
Published: June 2023

Background: Cerebral vasospasm is a feature of delayed cerebral ischemia that can occur after subarachnoid hemorrhage from cerebral aneurysm rupture. CTa is the universal first line diagnostic modality (sensitivity 79.6%, specificity 93.1%). We aim to determine whether specific vasospasm-associated radiographical and clinical features predicts cerebral vasospasm with comparable accuracy. Methods: Our cohort included 403 patients between 2006-2019. We used clinical predictive features including: day since rupture, transcranial doppler Lindegaard ratio, MCA velocity, ICA velocity, physical examination, and radiographical predictive features including: volume of hematoma, artifact, aneurysm, as our training dataset with true positives being digital subtraction angiography confirmed vasospasm. We used a decision-tree classifier from Scikit-learn library for training and testing of the model. Results: Our model trained on clinical and radiographical predictive features achieved sensitivity 93%, specificity 67%, F1 score 0.88. When using only radiographical features, we reached sensitivity 90%, specificity 55%, F1 score 0.83. When using only clinical features, we reach sensitivity 70%, specificity 93%, F1 score 0.87. Conclusions: We show that our vasospasm predictive model achieves adequate sensitivity, specificity, and F1 scores when compared to CTa. With further increase in dataset and fine-tuning of hyper-parameters, it is possible that our model may be used to optimize the vasospasm management pipeline.
P.130 Efficacy of decompressive craniectomy after subarachnoid hemorrhage: a propensity-matched analysis of a South Australian Cerebrovascular Registry
Authors: O’Donohoe TJ , Ovenden C , Bouras G , Chidambaram S , Davidson AS , Kleinig T , Abou-Hamden A
Published: June 2023

Background: The efficacy of decompressive craniectomy (DC) for patients with intracranial hypertension secondary to aneurysmal subarachnoid haemorrhage (aSAH) remains unclear. Methods: We identified aSAH patients who underwent DC following microsurgical aneurysm repair from a prospectively maintained cerebrovascular registry and compared their outcomes with a propensity-matched cohort who did not. Results: A total of 45 aSAH patients underwent DC between 01/09/2011 and 20/07/2020 and were compared with 45 propensity-matched controls. There were no differences in patient age (p=0.48), gender (p=0.53) or the proportion requiring endovascular vasospasm treatment (p=1.00). However, patients in the DC subgroup had a higher mean WFNS grade (3.47±1.53) compared with matched controls (2.8±1.25, p=0.03). Patients treated with DC had a higher rate of inpatient mortality (20.00% vs 0.00%, p=0.0025), unfavourable outcome (mRS≥4) at 1st (42.22% vs 11.11%, p=0.0016) and final (31.11% vs 2.94%, p<0.001) follow-up, and NIS-Subarachnoid Hemorrhage Outcome Measure positivity (40.00% vs 13.33%, p=0.0079). They also had a higher median mRS at 1st [3(2–4) vs 1(1–2), p<0.001], and final [2(1–4 vs 1(1 (0–2), p<0.001] follow-up. Conclusions: Patients treated with DC fared worse at every endpoint, which was disproportionate to the difference in presenting WFNS grade. These data do not support the use of DC following microsurgical clipping of a ruptured aneurysm.
P.136 The effectiveness of primary endoscopic third ventriculostomy (ETV) on cognition and gait outcomes in adults with congenital obstructive hydrocephalus (COH)
Authors: Isaacs A , Veilleux C , Hamilton M , Koester S
Published: June 2023

Background: Endoscopic third ventriculostomy (ETV) has become a treatment of choice for adults with clinically significant chronic obstructive hydrocephalus (COH). We evaluated the impact of ETV on cognition and gait in adults with COH. Methods: We retrospectively analyzed prospectively collected data from patients who underwent ETV as primary treatment for COH. Cognitive testing using the Montreal Cognitive Assessment (MoCA) and Symbol Digit Modalities Test (SDMT) was obtained pre-ETV at three months and one year postoperatively. Gait velocity was assessed using a 10-m walk test at each time point. Results: A total of 51 patients were identified. The mean age was 55±1 years, and 45% of patients were women. Baseline MoCA was 22.6±3.1, which improved to 25.7±3.0 and 26±3.4 at three months and one year, respectively (p<0.001). Half of the patients had a normal MoCA score post-ETV (IQR 26-27 at one year, p<0.001). Gait velocity was significantly improved at three months and 1-year post-ETV (p=0.0036). The cognitive and gait improvement one year after ETV was clinically significant. Conclusions: Cognition and gait improved at three months; results were sustained at 12 months post-ETV in adult patients with COH. ETV is an efficacious surgical consideration in this population.
P.141 The value of using flash visual evoked potentials monitoring during minimally invasive endoscopic meningioma resection: a retrospective chart review
Authors: Almarwani M , Ochoa-Sanchez R , Alsayadi S , Oumarou G , Kilty S , AlKherayf F
Published: June 2023

Background: Endoscopic endonasal surgeries performed in areas involving the visual pathway are associated with postoperative visual dysfunction. We previously demonstrated that continued eye monitoring during surgery by flash visual evoked potential (FVEP) represents a good method to prevent/reduce visual deficit post-surgery. We wondered whether FVEP monitoring may be more beneficial in patients with meningioma, strongly associated with postoperative visual loss.

The aim was to explore the visual capacity in patients subjected to meningioma resection at The Ottawa Hospital. Methods: A retrospective chart review of patients who underwent minimally invasive endoscopic skull base surgery and FVEP monitoring for meningioma resection (July 2018 to present) was conducted. Only patients with available pre- (up to 3 months) and post-surgery (1-9 months) visual evaluation were analyzed. Results: 40 eyes were included (20 patients). The median age was 61 years (range:43-84) and 90% of patients were female. The LogMAR visual acuity was not significantly modified post-surgery (from +0.25 to +0.21; p=0.7). Color vision (# errors reading Ishihara/16-plates) was not modified post-surgery (from 2.6 to 3.2; p=0.6). Visual field (Humphrey, 32-2) was not significantly modified post-surgery (from 78.1% to 81.9%; p=0.7). Conclusions: The prevention of visual pathway injury during surgery by FVEP monitoring prevents visual deficits after endoscopic meningioma resection.
GR.1 Different functional consequences result in different phenotypes in CLCN4-related developmental and epileptic encephalopathy
Authors: Sahly AN , Guzman RE , Sierra-Marquez J , Bungert-Plümke S , Franzen A , Mougharbel L , Berrahmoune S , Dassi C , Srour M , Myers KA
Published: June 2023

Background: Variants in CLCN4 are implicated in neurodevelopmental disorder, X-linked intellectual disability, and epileptic encephalopathy. CLCN4 encodes ClC-4, which is hypothesized to play a role in ion homeostasis and intracellular trafficking. ClC-4 relies on its formation of heterodimers with ClC-3, which possesses signals for target organelles. Methods: Case-Series. Then, we performed heterologous expression, patch-clamp electrophysiology, confocal microscopy, and protein biochemistry experiments to characterize our patients’ ClC-4 variants. Results: All three male patients had developmental and epileptic encephalopathy. Patients #1 and #2 had normal-appearing brains on MRI and no dysmorphic features. Patient #3 had: microcephaly, microsomia, complete agenesis of the corpus-callosum; and, cerebellar and brainstem hypoplasia. Patient #1 had recurrent status epilepticus separated by months of seizure freedom, while Patient #2 and #3 had brief, daily seizures. The p.Gly342Arg variant impaired the heterodimerization capability of ClC-4. The p.Ile549Leu and p.Asp89Asn variants exhibited early transport-activation, with p.Asp89Asn favouring higher transport-activity of ClC-4. Conclusions: We extend the phenotypic spectrum of CLCN4 variants and demonstrate the pathological functional-consequences of three previously unclassified variants. The p.Gly342Arg variant lead to a loss-of-function phenotype; however, the p.Ile549Leu and p.Asp89Asn variants likely caused gain-of-function phenotypes. Targeted animal or induced pluripotent stem-cell models are needed to further understand epileptogenic mechanisms of CLCN4 variants.
GR.4 Neurophysiological and clinical effects of low-intensity transcranial ultrasound of the motor cortex in Parkinson’s disease
Authors: Cortez Grippe T , Oghli Y , Darmani G , Arora T , Sarica C , Nankoo J , Chen R
Published: June 2023

Background: Low-intensity transcranial ultrasound (TUS) is a non-invasive neuromodulation technique, which in theta burst mode (tbTUS) can increase cortical excitability. Parkinson’s disease (PD) has altered cortical excitability of motor cortex (M1). We evaluated the neurophysiological and clinical effects of M1 tbTUS in PD patients. Methods: Sixteen PD patients (4F, 59.5±9.7 years) in ON and OFF dopaminergic medication states, and 15 controls (5F, 61.9±8.7 years) were evaluated. tbTUS was applied for 80 seconds at M1 with 20W/cm2. Motor evoked potential (MEP) was recorded at baseline, at 5-minutes (T5), T30, and T60 after tbTUS. Motor (m)UPDRS was evaluated in PD at baseline and T60. Results: A linear mixed model on MEP amplitudes comparing PD-ON, PD-OFF and controls showed significant effect of time (F=4.83, p=0.003). Post-hoc analysis showed significant difference between baseline and T30 timepoints (p=0.0003). The MEP increase at T30 was higher in controls (66%), followed by PD-ON (41%) and PD-OFF (21%). PD-ON showed reduced mUPDRS at T60 when compared to PD-OFF, with significant effect of time (F=6.14, p=0.017) and group (F=5.39, p=0.025). Conclusions: tbTUS induced motor cortical plasticity is reduced in PD-OFF, that is partially restored by dopaminergic medications.Repeated sessions of tbTUS can be further investigated as a novel non-invasive treatment for PD.
B.3 Sex differences in thrombolysis and thrombectomy workflow: the INTERRSeCT study
Authors: Rebchuk AD , Hill MD , Goyal M , Demchuk A , Coutts SB , Asdaghi N , Dowlatshahi D , Holodinsky JK , Fainardi E , Shankar J , Najm M , Rubiera M , Khaw AV , Qiu W , Menon BK , Field TS
Published: June 2023

Background: Women are reported to have worse outcomes than men following ischemic stroke despite similar treatment effects for thrombolysis and endovascular treatment. Methods: We performed a post-hoc analysis of patients with acute ischemic stroke and intracranial occlusion enrolled in INTERRSeCT, an international prospective cohort study. We compared workflow times, reperfusion therapy choices, and 90-day modified Rankin scale (mRS) scores. Results: We included 575 patients, mean age 70.2 years (SD: 13.1) and 48.5% female. There were no significant sex differences in onset-to-CT (males: 115 minutes [IQR: 72-171], females: 114 minutes [IQR: 75-196] ) or CT-to-thrombolysis time (males: 24 minutes [IQR: 17-32], females: 23 minutes [IQR: 18-36]). However, female participants had a 12-minute faster CT-to-groin-puncture time, p=0.001. Reperfusion therapies did not significantly differ by sex. Reperfusion therapies included thrombolysis alone (males: 46%, females: 49%), EVT alone (males: 34%, females: 34%), thrombolysis plus EVT (males: 8%, females 9%) and conservative management (males: 12%, females: 8%). Median 90-day mRS was 2 (IQR: 1-4) in both males and females, p=0.1. Conclusions: In the INTERRSeCT cohort, rates of reperfusion therapy, workflow times and 90-day outcomes were similar between sexes, suggesting that women are not subject to any poorer performance in key quality indicators for reperfusion treatment for acute stroke.
E.5 Large scale network changes immediately after Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy (MRgLITT) for hypothalamic hamartoma
Authors: Richards O , Ebden M , Greuter L , Malik N , Rutka J , Drake J , Ibrahim G
Published: June 2023

Background: Hypothalamic hamartomas (HH) are a challenging cause of seizure in children, partly because the neural circuitry involved in ictogenesis is incompletely understood. We review our institutions’ use of magnetic resonance imaging-guided laser interstitial thermal therapy (MRgLITT) to treat hypothalamic hamartoma (HH) with resting-state fMRI performed immediately before and after ablation. Methods: Seed-based whole brain connectivity to thalamic regions of interest was performed immediately pre- and post- MRgLITT. Multivariable generalized linear models were used to correlate resting-state data with seizure outcomes. Results: Eight patients underwent MRgLITT treatments for HH, with a mean follow up of 29 months. Four patients (50%) were seizure free at 12 months and two (25%) had a significant improvement in seizure frequency. We identified reduced thalamocortical connectivity involving the anterior cingulate and posterior parietal regions, consistent with disconnection of the mammillothalamic tract and interruption of Papez circuit. Large-scale thalamocortical connectivity changes were driven by children who subsequently became seizure free. Conclusions: Disconnection of the mammillothalamic tract and interruption of thalamic circuitry in patients undergoing MRgLITT for HH appears to be associated with improved seizure outcomes. The ability to assess network changes immediately post- MRgLITT could enable operative adjustments to be made mid-procedure to optimize seizure outcome in real time.
Healthcare worker perceptions surrounding Staphylococcus aureus transmission and prevention practices in the neonatal intensive care unit
Authors: Partha Samik S. , Malone Sara M. , Bizzle Melissa , Ikpeama Geoffrey , Reich Patrick J. , Schuetz Carly R. , Fritz Stephanie A.
Published: June 2023

Objective:

To understand healthcare worker (HCW) perceptions surrounding Staphylococcus aureus transmission and prevention in the neonatal intensive care unit (NICU).

Design:

Qualitative case study with focus groups.

Setting:

A level IV, 150-bed NICU at a Midwestern academic medical center that conducts active surveillance and decolonization of S. aureus–positive patients.

Participants:

NICU HCWs, including bedside nurses, nurse managers, therapy services personnel, pediatric nurse practitioners, clinical fellows, and attending neonatologists.

Methods:

Semistructured focus group interviews, assembled by occupation, were conducted by 2 study team members. Interviews were video recorded and transcribed. Deductive coding and thematic analyses were performed using NVivo software.

Results:

In total, 38 HCWs participated in 10 focus groups (1–12 participants each), lasting 40–90 minutes. Four main themes emerged: (1) Methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) are inconsistently described as high risk. (2) Infection prevention interventions are burdensome. (3) Multiple sources of transmission are recognized. (4) opportunities exist to advance infection prevention. HCWs perceived MSSA to be less clinically relevant than MRSA. Participants expressed a desire to see published data supporting infection prevention interventions, including contact precautions, environmental cleaning, and patient decolonization. These practices were identified to be considerable burdens. HCWs perceived families to be the main source of S. aureus in the NICU, and they suggested opportunities for families to play a larger role in infection prevention.

Conclusions:

These data highlight opportunities for HCW and parental education, research, and reevaluating interventions aimed at improving infection prevention efforts to reduce the burden of S. aureus in NICU settings.
The role of new ICT-based systems in modern management special issue editors:
Authors: Jafari Navimipour Nima , Wan Shaohua , Pasumarti Srinivas Subbarao , Fazio Maria
Published: June 2023

In this special issue, we have collected eight articles that offer new points for research on information and communications technology (ICT)-based systems. We focused on the intuitive nature of the relationship between new ICT-based systems and contemporary management, forming an integrative unit of analysis instead of focusing solely on new ICT-based systems and leaving contemporary management as a moderating or mediating factor. This special issue promoted interdisciplinary research at the intersection of new ICT-based systems and contemporary management, including cybernetics systems and knowledge management, service managing and the Internet of things, cloud and marketing management, business process re-engineering and management, knowledge management, and strategic business management, among others.
Political Trust and Ecological Crisis Perceptions in Developing Economies: Evidence from Ecuador
Authors: Verner Marija
Published: June 2023

Could an individual’s perception of the possibility of a future ecological crisis be linked to their level of political trust? Studies of environmental attitudes have identified political trust as an important predictor of support for environmental taxation or risk perceptions surrounding specific local environmental hazards, but less is known about its role when environmental risks are perceived as diffuse and distant. Using original survey data from Ecuador, this article finds that political distrust predicts heightened ecological crisis perceptions and that higher educational attainment intensifies this relationship. A follow-up analysis of the AmericasBarometer’s Ecuador survey shows that political distrust also predicts higher concern about climate change. These findings suggest that when evaluations of political institutions reflect perceptions of environmental risks, individuals blame the government for environmental failures. The implications of this study are particularly relevant for political institutions in developing economies, where the public sector often spearheads development efforts.