Publications by authors named "Johanna M Ospel"
This two part series on statistical principles in neurointervention offers a comprehensive foundation for neurointerventionalists to engage with both fundamental and advanced statistical principles. This series aims to equip neurointerventionalists with essential statistical knowledge for critically reviewing literature and conducting methodologically sound research. Part one of this series covered fundamental concepts such as frequentism, study types, data types, summarization, visualization, hypothesis testing, and univariable analysis.
View Article and Find Full Text PDFNeurointervention has seen significant advancements in recent decades with the adoption of myriad new technologies and techniques. Initially reliant on case reports and small case series, we now benefit from multicenter studies and randomized trials that can provide robust practice-changing evidencea and often employ sophisticated statistical methods. This two-part series on statistical principles in neurointervention aims to equip neurointerventionalists with essential statistical knowledge for critically reviewing literature and conducting methodologically sound research.
View Article and Find Full Text PDFBackground: In the ESCAPE-NA1 trial (Efficacy and Safety of Nerinetide for the Treatment of Acute Ischemic Stroke), treatment with nerinetide was associated with a smaller infarct volume among patients who did not receive intravenous alteplase. We assessed the effect of nerinetide on the surrogate imaging outcome of final infarct volume in patients who did not receive intravenous alteplase and explored predictors of outcome and modifiers of nerinetide's effect on infarct volume.
Methods: ESCAPE-NA1 was a multicenter, randomized trial in which patients with acute stroke with a baseline Alberta Stroke Program Early CT Score >4, undergoing endovascular thrombectomy, were randomized to receive intravenous nerinetide or placebo.
Article Synopsis
- Carotid plaques may play a significant role in causing ischemic strokes, and this study evaluated their characteristics in relation to strokes that occur on either side of the affected carotid artery.
- Researchers analyzed data from the ESCAPE-NA1 trial, focusing on patients with embolic stroke of undetermined source (ESUS) who underwent thrombectomy, and looked for "vulnerable carotid plaques" using various imaging criteria.
- The findings revealed that vulnerable plaques, characterized by surface irregularity and significant stenosis, were significantly more common in the carotid arteries on the same side as the stroke, highlighting the importance of monitoring these plaques for better stroke risk assessment.
Background: The effect of embolization of the middle meningeal artery in patients with subacute or chronic subdural hematoma is uncertain.
Methods: We performed a multicenter, open-label, randomized trial in China, involving patients with symptomatic nonacute subdural hematoma with mass effect. Patients were assigned to undergo burr-hole drainage or receive nonsurgical treatment at the surgeon's discretion, and patients in each group were then randomly assigned, in a 1:1 ratio, to undergo middle meningeal artery embolization with liquid embolic material or to receive usual care.
Cerebral ischemic injury occurs when blood flow drops below a critical level, resulting in an energy failure. The progressive transformation of hypoperfused viable tissue, the ischemic penumbra, into infarction is a mechanism shared by patients with ischemic stroke if timely reperfusion is not achieved. Yet, the pace at which this transformation occurs, known as the infarct growth rate (IGR), exhibits remarkable heterogeneity among patients, brain regions, and over time, reflecting differences in compensatory collateral flow and ischemic tolerance.
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- Most stroke researchers currently use frequentist statistics, but there is a growing trend towards using Bayesian statistics in stroke research.
- Bayesian statistics focus on updating the probability of parameters based on observed data and prior beliefs, allowing for more flexible interpretations of treatment effectiveness.
- This review discusses the fundamental concepts of Bayesian statistics in stroke trials, compares them to frequentist methods with examples, and explains how to conduct and interpret Bayesian analyses.
Article Synopsis
- * Patients are categorized into anemic and nonanemic groups, as well as hyperglycemic and normoglycemic groups, to see how these factors affect the underestimation of ischemic core volume (ICuV).
- * Results showed that hyperglycemic patients had a higher rate of "perfusion scotoma" (65%) and a larger ICuV compared to normoglycemic patients, suggesting metabolic factors can significantly influence stroke outcomes.
Article Synopsis
- The study assessed how the quality of reperfusion affects clinical and radiological outcomes in patients from the ESCAPE NA1 trial.
- Researchers analyzed different reperfusion patterns using the expanded Treatment in Cerebral Infarction (eTICI) Scale to compare patient outcomes, including rates of good or excellent clinical recovery, symptomatic hemorrhage, and death.
- Results showed that higher reperfusion grades were linked to better clinical outcomes and lower mortality rates, regardless of how many attempts were needed to achieve them, or the speed of reperfusion.
Article Synopsis
- * A systematic review of 122 surveys from 2000 to 2023 found a significant annual increase in publications, focusing mainly on stroke and aneurysm treatment, with a median response rate of 58.5%.
- * Only about half of the surveys published their questionnaires and fewer reported vital metrics like response rates and data collection methods, indicating potential gaps in survey transparency and quality.
Article Synopsis
- * The review highlights various reasons for EVT underutilization, including challenges faced by healthcare providers, patients, and stakeholders in developing these services.
- * It emphasizes the need for implementation research, strategic partnerships, and advocacy efforts to address these challenges and improve access to EVT.
Rationale: Clinical outcomes in acute ischemic stroke due to medium vessel occlusion (MeVO) are often poor when treated with best medical management. Data from non-randomized studies suggest that endovascular treatment (EVT) may improve outcomes in MeVO stroke, but randomized data on potential benefits and risks are hitherto lacking. Thus, there is insufficient evidence to guide EVT decision-making in MeVO stroke.
View Article and Find Full Text PDFBackground: Cerebral venous thrombosis (CVT) is a rare but severely disabling form of stroke. Acute treatment mainly consists of medical management, since there is no robust evidence suggesting the benefit of endovascular treatment for CVT. Given the relative lack of data to guide acute treatment decision-making, CVT treatment decisions are mostly made on a case-by-case basis.
View Article and Find Full Text PDFBackground And Purpose: Infarcts in acute ischemic stroke (AIS) patients may continue to grow even after reperfusion, due to mechanisms such as microvascular obstruction and reperfusion injury. We investigated whether and how much infarcts grow in AIS patients after near-complete (expanded Thrombolysis in Cerebral Infarction [eTICI] 2c/3) reperfusion following endovascular treatment (EVT), and to assess the association of post-reperfusion infarct growth with clinical outcomes.
Methods: Data are from a single-center retrospective observational cohort study that included AIS patients undergoing EVT with near-complete reperfusion who received diffusion-weighted magnetic resonance imaging (MRI) within 2 hours post-EVT and 24 hours after EVT.
Article Synopsis
- The study explores the connection between infarct volume in acute ischemic stroke patients and their chances of achieving good clinical outcomes based on the modified Rankin Scale (mRS).
- Using data from the ESCAPE-NA1 trial, researchers analyzed how changes in infarct volume influence the probabilities of recovery in 1,099 patients over 24 hours post-treatment.
- Findings indicate a nearly linear relationship between infarct volume and good outcomes up to 250 mL, suggesting that significant reductions in infarct size are necessary to improve chances of recovery, especially as patients with volumes over 250 mL have very low probabilities of good outcomes.
Article Synopsis
- * The study analyzed data from the ESCAPE-NA1 trial, involving 408 patients, and found that 35% experienced hemorrhagic transformation, mostly classified as hemorrhagic infarction or parenchymal hematoma.
- * Larger volumes of low relative cerebral blood flow (CBF) were associated with an increased risk of parenchymal hematoma, suggesting that CBF metrics could help assess the risk of complications following treatment.
Background: Endovascular treatment (EVT) has become standard of care for patients with anterior circulation large vessel occlusion (LVO) stroke, with indications having recently expanded to late time-window and large ischemic core patients. There is conflicting evidence on whether EVT reduces mortality or only disability. We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of EVT on mortality and severe disability.
View Article and Find Full Text PDFBackground: To assess the association of qualitative and quantitative infarct characteristics and 3 cognitive outcome tests, namely the Montreal Cognitive Assessment (MOCA) for mild cognitive impairment, the Boston Naming Test for visual confrontation naming, and the Sunnybrook Neglect Assessment Procedure for neglect, in large vessel occlusion stroke.
Methods: Secondary observational cohort study using data from the randomized-controlled ESCAPE-NA1 trial (Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke), in which patients with large vessel occlusion undergoing endovascular treatment were randomized to receive either intravenous Nerinetide or placebo. MOCA, Sunnybrook Neglect Assessment Procedure, and 15-item Boston Naming Test were obtained at 90 days.