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Introduction: Despite complete recanalization by mechanical thrombectomy, abnormal perfusion can be detected on MRI obtained post-endovascular therapy (EVT). The presence of residual perfusion abnormalities post-EVT may be associated with blood-brain barrier breakdown in response to mechanical disruption of the endothelium from multiple-pass thrombectomy. We hypothesize that multiple-pass versus single-pass thrombectomy is associated with a higher rate of residual hypoperfusion and increased lesion growth at 24 h., Materials and Methods: For this analysis, we included patients presenting to one of two stroke centers between January 2015 and February 2018 with an acute ischemic stroke within 12 h from symptom onset if they had a large vessel occlusion of the anterior circulation documented on magnetic resonance angiography or CTA, baseline MRI pre-EVT with imaging evidence of hypoperfusion, underwent EVT, and had a post-EVT MRI with qualitatively interpretable perfusion-weighted imaging data at 24 h. MRI Tmax maps using a time delay threshold of >6 s were used to quantitate hypoperfusion volumes. Residual hypoperfusion at 24 h was solely defined as Tmax volume >10 mL with >6 s delay. Complete recanalization was defined as modified treatment in cerebral infarction visualized on angiography at EVT completion. Hyperintense acute reperfusion injury marker was assessed on post-EVT pre-contrast fluid-attenuated inversion recovery at 24 h. Major early neurological improvement was defined as a reduction of the admission National Institutes of Health Stroke Scale by ≥8 points or a score of 0-1 at 24 h. Good functional outcome was defined as 0-2 on the modified Rankin Scale on day 30 or 90., Results: Fifty-five patients were included with median age 67 years, 58% female, 45% Black/African American, 36% White/Caucasian, median admission National Institutes of Health Stroke Scale 19, large vessel occlusion locations: 71% M1, 14.5% iICA, 14.5% M2, 69% treated with intravenous recombinant tissue plasminogen activator. Of these, 58% had multiple-pass thrombectomy, 39% had residual perfusion abnormalities at 24 h, and 64% had severe hyperintense acute reperfusion injury marker at 24 h. After adjusting for complete recanalization, only multiple-pass thrombectomy (odds ratio, 4.3 95% CI, 1.07-17.2; p = 0.04) was an independent predictor of residual hypoperfusion at 24 h. Patients with residual hypoperfusion had larger lesion growth on diffusion-weighted imaging (59 mL vs. 8 mL, p < 0.001), lower rate of major early neurological improvement (24% vs. 70%, p = 0.002) at 24 h, and worse long-term outcome based on the modified Rankin Scale at 30 or 90 days, 5 versus 2 (p < 0.001)., Conclusions: Our findings suggest that incomplete reperfusion on post-EVT MRI is present even in some patients with successful recanalization at the time of EVT and is associated with multiple-pass thrombectomy, lesion growth, and worse outcome. Future studies are needed to investigate whether patients with residual hypoperfusion may benefit from immediate adjunctive therapy to limit lesion growth and improve clinical outcome., (© 2021 S. Karger AG, Basel.)

Introduction: The absence of an ischemic lesion on MRI fluid-attenuated inversion recovery (FLAIR) is helpful in predicting stroke onset within 4.5 h. However, some ischemic strokes become visible on FLAIR within 4.5 h. We hypothesized that the early lesion visibility on FLAIR may predict stroke outcome 90 days after intravenous (IV) thrombolysis, independent of time., Materials and Methods: We analyzed data from acute ischemic stroke patients presenting over the last 10 years who were screened with MRI and treated with IV thrombolysis within 4.5 h from onset. Three independent readers assessed whether ischemic lesions seen on diffusion-weighted imaging were also FLAIR positive based on visual inspection. Multivariable regression analyses were used to obtain an adjusted odds ratio of favorable clinical and radiological outcomes based on FLAIR positivity., Results: Of 297 ischemic stroke patients, 25% had lesion visibility on initial FLAIR. The interrater agreement for the FLAIR positivity assessment was 84% (κ = 0.604, 95% CI: 0.557-0.652). Patients with FLAIR-positive lesions had more right hemispheric strokes (57 vs. 41%, p = 0.045), were imaged later (129 vs. 104 min, p = 0.036), and had less frequent favorable 90-day functional outcome (49 vs. 63%, p = 0.028), less frequent early neurologic improvement (30 vs. 58%, p = 0.001), and more frequent contrast extravasation to the cerebrospinal fluid space (44 vs. 26%, p = 0.008)., Conclusions: Early development of stroke lesion on FLAIR within 4.5 h of onset is associated with reduced likelihood of favorable 90-day outcome after IV thrombolysis., (Published by S. Karger AG, Basel.)

Objects: To identify predictors of acute ischemic stroke (AIS) among patients presenting to the Emergency Department (ED) with dizziness, imbalance, or vertigo (DIV) based on demographic and clinical characteristics.Methods: We identified patients admitted to the hospital after presenting to the ED with DIV from the Statewide Planning and Research Cooperative System database of New York from 2010 to 2014. Demographic and clinical characteristics were systematically collected. Multivariable logistic regression was used to determine predictors of a discharge diagnosis of AIS.Results: Among 77,993 patients with DIV, 3857 (4.9%) had a discharge diagnosis of AIS. Admission presentation of imbalance, African-American race, history of hypertension, diabetes mellitus, hypercholesterolemia, tobacco use, atrial fibrillation, and prior AIS due to extracranial artery atherosclerosis were each positively associated with an AIS diagnosis independently. Factors negatively associated with an AIS discharge diagnosis included: admission presentation of vertigo, female sex, age > 81, history of anemia, coronary artery disease, asthma, depressive disorders, and anxiety disorders.Conclusions: Multiple potential positive and negative predictive AIS risk factors were identified. Combining with currently available centrally-caused dizziness prediction tools, these newly identified factors could provide more accurate AIS risk stratifying method for DIV patients. [ABSTRACT FROM AUTHOR]