We\u27re Swarming Again! Swarming, Collectivity, and Trope: The Case of Extinction Rebellion

This thesis explores the rhetoric of the eco-movement Extinction Rebellion, focusing on the use of swarming and nature tropes to mobilize collective action and revivify contemporary notions of collectivity. Drawing on rhetoric of social movement scholarship, cultural studies, and psychoanalysis, this essay theorizes swarming as a tropological economy that expands the conditions of propriety in the context of collectivity. Through an analysis of Extinction Rebellion’s discourse, this study demonstrates how the naturalization of swarming tropes works in various ways to rewild conventional political discourse, galvanize disruptive collective assembly, and challenge green neoliberalism. Advisor: Casey Ryan Kell

Risk of intracerebral haemorrhage from hypertension is greatest at an early age

Introduction The risk of intracerebral haemorrhage (ICH) associated with hypertension (HTN) is well documented. While the prevalence of HTN increases with age, the greatest odds ratio (OR) for HTN as a risk for ischemic stroke is at an early age. We sought to evaluate if the risk for ICH from HTN was higher in the youngest patients of each race. Patients and methods The Ethnic/Racial Variations of ICH (ERICH) study is a prospective multicenter case-control study of ICH among whites, blacks, and Hispanics. Participants were divided into age groups based on race-specific quartiles. Cases in each race/age group were compared to controls using logistic regression (i.e., cases and controls unmatched). The probability of ICH among cases and controls for each race were compared against independent variables of HTN, quartile of age and interaction of quartile and age also using logistic regression. Results Overall, 2033 non-lobar ICH cases and 2060 controls, and 913 lobar ICH cases with 927 controls were included. ORs were highest in the youngest age quartile for non-lobar haemorrhage for blacks and Hispanics and highest in the youngest quartile for lobar haemorrhage for all races. The formal test of interaction between age and HTN was significant in all races for all locations with the exception of lobar ICH in whites (p = 0.2935). Discussion Hypertension is a strong independent risk factor for ICH irrespective of location among persons of younger age, consistent with the hypothesis that first exposure to HTN is a particularly sensitive time for all locations of ICH. </jats:sec

Abstract WP213: Comparison of Clinical and Imaging Characteristic of Cryptogenic Stroke to Known Ischemic Subtypes

Introduction: Cryptogenic stroke is defined as not attributable to an identified source despite standard evaluation. The absence of small vessel or large artery disease in such evaluation suggests that cryptogenic stroke may be largely cardioembolic. We hypothesized that cryptogenic stroke would be similar to cardioembolic stroke in clinical and imaging characteristics. Methods: The Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) is a population-based study that tracks the regional incidence of stroke. A convenient subsample from the 2010 GCNKSS ischemic stroke cohort (N= 368) was selected for detailed neuroimaging analysis. The study physician subtyped cases based on clinical, radiographic and laboratory findings (carotid ultrasound, echocardiography, vascular imaging). Subtypes included cryptogenic, cardioembolic, large-vessel, small-vessel, undetermined, and other. Three radiologists performed imaging analysis including number of acute infarcts, location and white matter hyperintensity (WMH). Infarct volume was segmented using manual tracing. Results: Of 368 ischemic stroke cases with imaging data, subtypes were 26.4% cryptogenic, 16.3% large vessel, 15.5% small vessel, 24.7% cardioembolic, 5.4% undetermined, and 11.7% other. Compared to cardioembolic, cryptogenic stroke patients were younger, had less hypertension, higher alcohol use, smaller infarct volume and differed in location of stroke. Cryptogenic stroke had more clinical and radiological features in common with large and small-vessel stroke (Table). Undetermined and other had no significant differences to cryptogenic. Conclusion: Contrary to our hypothesis, cryptogenic stroke was different from cardioembolic stroke and appeared more similar to large vessel stroke in clinical and radiological characteristics. Further testing on a larger sample size to evaluate the impact of cardiac event monitoring on subtype distribution is needed. </jats:p

Abstract TP53: NIHSS and Variation of Infarct Volume by Hemisphere

Introduction: The National Institute of Health Stroke Scale (NIHSS) is the most widely used measure of neurological deficits in clinical trials. Using the placebo arm of the NINDS t-PA Stroke Trial, it has been demonstrated that the total volume of cerebral infarction in patients with similar NIHSS scores is greater for right compared to left hemisphere strokes. Our objective was to verify this finding in a non-clinical trial, independent data set of acute ischemic strokes. Methods: The Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) is a population-based study that tracks the incidence of stroke. A convenient subsample from the 2010 GCNKSS ischemic stroke cohort (N= 368) underwent detailed imaging analysis. Research nurses abstracted patient reords to include baseline retrospective NIHSS score. The 24 hour infarct volume was segmented using manual tracing. NIHSS was compared between left and right brain using Wilcoxon rank sum test. Spearman rank correlation determined the association between the NIHSS score and infarct volume by hemisphere. Patients were stratified by NIHSS (0 to 5, 6 to 20, and greater than 20). Results: Among 368 ischemic stroke subjects with imaging data, excluded were 77 brainstem or cerebellar infarcts, 37 undetermined volume, 1 missing NIHSS, and 3 undetermined laterality. For the remaining 250 patients, 132 were left and 118 were right hemisphere strokes, and 210 had an MRI and 40 had CT. Median time from onset to imaging was 24 hours. Baseline NIHSS was similar by hemisphere and correlated with stroke volume (r=0.38, p&lt;0.01). The infarct volumes of right hemisphere strokes were greater than left hemisphere (p-value=0.02) (Table). Conclusion: The NIHSS score correlates with volume by hemisphere, but has a larger infarct volume for right hemisphere than left hemisphere for similar NIHSS. This likely reflects the different weighting of the NIHSS with regard to language. This finding confirms prior results in an independent dataset. </jats:p

Abstract TP10: Inflammatory And Neurodegenerative Gene Expression Changes Occur Long-term After ICH

Objective: There is a high prevalence of progressive cognitive impairment in intracerebral hemorrhage (ICH) survivors. We sought to identify gene expression changes, in association with long-term neurodegeneration, among patients 12-24 months post-ICH. Methods: The Recovery and Outcomes from StrokE (ROSE) study prospectively recruits patients with spontaneous, supratentorial ICH, collecting baseline peripheral blood samples and MRI with diffusion tract imaging (DTI). The Recovery of StrokE-Longitudinal Assessment with Neuroimaging (ROSE-LAWN) study performs long term follow-up at 12-24 months on cases enrolled in ROSE. We report on the first five cases enrolled in the ROSE-LAWN study from December 2020 to March 2021. Controls were matched to an overall ICH population by age, sex, and race. RNA-sequencing, aligned to human genome assembly GRCh38, was tested for differential gene expression. Canonical pathway enrichment and network analyses were computed for differentially expressed genes using Ingenuity Pathway Analysis, STRING and MCODE. Results: RNA-seq analysis of 5 ICH cases [male, 80%; median age, 61 (45 - 73); black, 40%; ICH volume, 14.88cc ± 13.07] and 13 controls [male, 54%; median age, 74 (69 - 79); black, 15%] identified 554 differentially expressed genes (genomic control adjusted p &lt; 0.01), of which 24 met the false discovery rate correction for multiple comparisons (FDR &lt; 0.05). The most significant difference was observed in hypoxia up-regulated 1 ( HYOU1), a heat shock protein related gene (p = 2.64E-11). Pathway analysis identified enrichment of dopamine and serotonin receptor signaling (p = 8.74E-03, 2.23E-02), cell cycle regulation (p = 1.75E-02) and agranulocyte adhesion pathways (p = 2.18E-02). Comparison of baseline and follow-up MRI DTI demonstrated extensive cortical tract degeneration, beyond the initial injury. Conclusion: These results provide novel evidence of significant gene expression changes occurring years after the initial ICH. Despite resolution of the ICH, persistent inflammation may correlate with progressive neurodegeneration and subsequent cognitive impairment in ICH survivors. Future studies with greater sample sizes are supported by this work. </jats:p

Combining Imaging and Genetics to Predict Recurrence of Anticoagulation-Associated Intracerebral Hemorrhage

Background and Purpose: For survivors of oral anticoagulation therapy (OAT)–associated intracerebral hemorrhage (OAT-ICH) who are at high risk for thromboembolism, the benefits of OAT resumption must be weighed against increased risk of recurrent hemorrhagic stroke. The ε2/ε4 alleles of the apolipoprotein E ( APOE ) gene, MRI-defined cortical superficial siderosis, and cerebral microbleeds are the most potent risk factors for recurrent ICH. We sought to determine whether combining MRI markers and APOE genotype could have clinical impact by identifying ICH survivors in whom the risks of OAT resumption are highest. Methods: Joint analysis of data from 2 longitudinal cohort studies of OAT-ICH survivors: (1) MGH-ICH study (Massachusetts General Hospital ICH) and (2) longitudinal component of the ERICH study (Ethnic/Racial Variations of Intracerebral Hemorrhage). We evaluated whether MRI markers and APOE genotype predict ICH recurrence. We then developed and validated a combined APOE -MRI classification scheme to predict ICH recurrence, using Classification and Regression Tree analysis. Results: Cortical superficial siderosis, cerebral microbleed, and APOE ε2/ε4 variants were independently associated with ICH recurrence after OAT-ICH (all P &lt;0.05). Combining APOE genotype and MRI data resulted in improved prediction of ICH recurrence (Harrell C: 0.79 versus 0.55 for clinical data alone, P =0.033). In the MGH (training) data set, CSS, cerebral microbleed, and APOE ε2/ε4 stratified likelihood of ICH recurrence into high-, medium-, and low-risk categories. In the ERICH (validation) data set, yearly ICH recurrence rates for high-, medium-, and low-risk individuals were 6.6%, 2.5%, and 0.9%, respectively, with overall area under the curve of 0.91 for prediction of recurrent ICH. Conclusions: Combining MRI and APOE genotype stratifies likelihood of ICH recurrence into high, medium, and low risk. If confirmed in prospective studies, this combined APOE -MRI classification scheme may prove useful for selecting individuals for OAT resumption after ICH. </jats:sec

Combining Imaging and Genetics to Predict Recurrence of Anticoagulation-Associated Intracerebral Hemorrhage

Background and Purpose: For survivors of oral anticoagulation therapy (OAT)–associated intracerebral hemorrhage (OAT-ICH) who are at high risk for thromboembolism, the benefits of OAT resumption must be weighed against increased risk of recurrent hemorrhagic stroke. The ε2/ε4 alleles of the apolipoprotein E ( APOE ) gene, MRI-defined cortical superficial siderosis, and cerebral microbleeds are the most potent risk factors for recurrent ICH. We sought to determine whether combining MRI markers and APOE genotype could have clinical impact by identifying ICH survivors in whom the risks of OAT resumption are highest. Methods: Joint analysis of data from 2 longitudinal cohort studies of OAT-ICH survivors: (1) MGH-ICH study (Massachusetts General Hospital ICH) and (2) longitudinal component of the ERICH study (Ethnic/Racial Variations of Intracerebral Hemorrhage). We evaluated whether MRI markers and APOE genotype predict ICH recurrence. We then developed and validated a combined APOE -MRI classification scheme to predict ICH recurrence, using Classification and Regression Tree analysis. Results: Cortical superficial siderosis, cerebral microbleed, and APOE ε2/ε4 variants were independently associated with ICH recurrence after OAT-ICH (all P <0.05). Combining APOE genotype and MRI data resulted in improved prediction of ICH recurrence (Harrell C: 0.79 versus 0.55 for clinical data alone, P =0.033). In the MGH (training) data set, CSS, cerebral microbleed, and APOE ε2/ε4 stratified likelihood of ICH recurrence into high-, medium-, and low-risk categories. In the ERICH (validation) data set, yearly ICH recurrence rates for high-, medium-, and low-risk individuals were 6.6%, 2.5%, and 0.9%, respectively, with overall area under the curve of 0.91 for prediction of recurrent ICH. Conclusions: Combining MRI and APOE genotype stratifies likelihood of ICH recurrence into high, medium, and low risk. If confirmed in prospective studies, this combined APOE -MRI classification scheme may prove useful for selecting individuals for OAT resumption after ICH

Risk Factors Associated With Mortality and Neurologic Disability After Intracerebral Hemorrhage in a Racially and Ethnically Diverse Cohort

Intracerebral hemorrhage (ICH) is the most severe subtype of stroke. Its mortality rate is high, and most survivors experience significant disability. To assess primary patient risk factors associated with mortality and neurologic disability 3 months after ICH in a large, racially and ethnically balanced cohort. This cohort study included participants from the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study, which prospectively recruited 1000 non-Hispanic White, 1000 non-Hispanic Black, and 1000 Hispanic patients with spontaneous ICH to study the epidemiological characteristics and genomics associated with ICH. Participants included those with uniform data collection and phenotype definitions, centralized neuroimaging review, and telephone follow-up at 3 months. Analyses were completed in November 2021. Patient demographic and clinical characteristics as well as hospital event and imaging variables were examined, with characteristics meeting P < .20 considered candidates for a multivariate model. Elements included in the ICH score were specifically analyzed. Individual characteristics were screened for association with 3-month outcome of neurologic disability or mortality, as assessed by a modified Rankin Scale (mRS) score of 4 or greater vs 3 or less under a logistic regression model. A total of 25 characteristics were tested in the final model, which minimized the Akaike information criterion. Analyses were repeated removing individuals who had withdrawal of care. A total of 2568 patients (mean [SD] age, 62.4 [14.7] years; 1069 [41.6%] women and 1499 [58.4%] men) had a 3-month outcome determination available, including death. The final logistic model had a significantly higher area under the receiver operating characteristics curve (C = 0.88) compared with ICH score alone (C = 0.76; P < .001). Among characteristics associated with neurologic disability and mortality were larger log ICH volume (OR, 2.74; 95% CI, 2.36-3.19; P < .001), older age (OR per 1-year increase, 1.04; 95% CI, 1.02-1.05; P < .001), pre-ICH mRS score (OR, 1.62; 95% CI, 1.41-1.87; P < .001), lobar location (OR, 0.22; 95% CI, 0.16-0.30; P < .001), and presence of infection (OR, 1.85; 95% CI, 1.42-2.41; P < .001). The findings of this cohort study validate ICH score elements and suggest additional baseline and interim patient characteristics were associated with variation in 3-month outcome