Brinjikji, Waleed

Background and Purpose: Endovascular thrombectomy (EVT) is an effective treatment for acute ischemic stroke (AIS) due to large vessel occlusion of the anterior circulation (AC-LVO). Randomized trials of posterior circulation large vessel occlusion (PC-LVO) patients have failed to show a benefit of EVT over medical therapy (MEDT). We performed a systematic review and meta-analysis to understand better whether EVT is beneficial for PC-LVO. Methods: Using the Nested Knowledge AutoLit living review platform, we identified randomized control trials and prospective studies that reported functional outcomes in patients with PC-LVO treated with EVT versus MEDT. The primary outcome variable was 90-day modified Rankin Scale (mRS) 0-3, and secondary outcome variables included 90-day mRS 0-2, 90-day mortality, and rate of symptomatic intracranial hemorrhage (sICH). A separate random effects model was fit for each outcome measure to calculate pooled odds ratios. Results: Three studies with 1,248 patients, 860 in the EVT arm and 388 in the MEDT arm, were included in the meta-analysis. The favorable outcome rate (mRS 0-3) in EVT patients was 39.9% (95% CI: 30.6-50.1%) versus 24.5% in MEDT patients (95% CI: 9.6-49.8%). EVT patients had higher mRS 0-2 rates (31.8% [95% CI: 25.7-38.5%] versus 19.7% [95% CI: 7.4-42.7%]) and lower mortality (42.1% [95% CI: 35.9-48.6%] versus 52.8% [95% CI: 33.3-71.5%]) compared to MEDT patients, but neither result was statistically significant. EVT patients were more likely to develop sICH (OR=10.36; 95% CI: 3.92-27.40). Conclusions: EVT treatment of PC-LVO trended toward superior functional outcomes and reduced mortality compared to MEDT despite a trend toward increased sICH in EVT patients. Existing randomized and prospective studies are insufficiently powered to demonstrate a benefit of EVT over MEDT in PC-LVO patients.

Introduction: Ample evidence exists in support of the anti-inflammatory properties of statins which in turn could affect arterial thrombosis. Compositional analysis of thrombi retrieved by MT may provide us with knowledge useful for evaluating the effect of current Statin therapy on thrombus composition. Methods: Consecutive AIS-LVO patients were included. Histopathological evaluation of thrombi retrieved during MT was performed using Martius Scarlet Blue staining (MSB) and immunohistochemistry for von Willebrand Factor (vWF) and anti-citrulinated H3 (CitH3; NETs marker) and the composition of thrombi was determined using image analysis software. Thrombus was considered rich in a given composition if that composition was higher than its overall mean. We reviewed patient’s medication records and cataloged any statin therapy prior to MT. Results: 117 patients were included in this study. The mean density of red blood cells (RBCs), white blood cells (WBCs), platelets (PLT), fibrin (FIB), vWF and NETs (CitH3) in thrombi was 43.4%, 3.7%, 23.6%, 29.3%, 14.3% and 21.1% respectively. Twenty-seven patients were taking Statins at the time of MT. Statins were not associated with pre-thrombectomy IV-tPA, and stroke etiology (p values: >0.05). There was no association between Statins and thrombi composition and type (p values: >0.05 for all thrombus components and type). Additionally, Statins were not associated with MT outcomes including number of device passes and final mTICI score. Conclusion: Pre-stroke Statin therapy was not associated with differences in thrombus composition.

Introduction: Digital subtraction angiography (DSA) is currently the gold standard for evaluation of moyamoya disease (MMD) and is the basis for several grading systems. Non-invasive modalities such as MRA are also used in assessment of MMD. Accurate implementation of these staging systems for use with MRA would imply a less-invasive method of MMD monitoring. Methods: This was a single-center retrospective study that compared MRA to reference DSA studies in determining MMD severity using Berlin and modified Suzuki (mSG) grading systems A single reviewer assigned modified Suzuki and Berlin grades to all included hemispheres on both MRA and DSA. The mean difference between MRA and DSA grades for each DSA reference grade was determined utilizing both grading systems. The distribution of scores was also compared between MRA and DSA using both grading systems. Results: A total of 166 cerebral hemispheres in 90 patients were included: The mean age at MMD diagnosis was 34.8 years (standard deviation [SD] = 14.2), and fifty-three patients (63.9%) were male. Mean MRA grades were significantly lower than DSA reference grades 3 and 4 utilizing the mSG system (p = <0.0001 in both cases); A similar pattern was observed for Berlin grades 2 and 3 (p = <0.0001, Table 1 ). The distribution of modified Suzuki grades on MRA was skewed toward relatively lower grades as compared to DSA (p = <0.0001): This pattern was also true for Berlin grades as well (p = <0.0001, Table 2 ). Conclusions: DSA is essential in the evaluation of MMD, as MRA is shown to underestimate disease stage, with a greater degree of underestimation in more severe disease. We suggest DSA be performed in order to aid in appropriate treatment planning.

Introduction: Selection criteria for endovascular thrombectomy (EVT) for emergent large-vessel occlusion (ELVO) stroke increasingly rely on CT perfusion (CTP) findings at presentation. While perfusion imaging is used to estimate the likelihood of deriving long-term functional benefit from EVT, there is comparatively little data on how perfusion deficits relate to domains of neurological function. Here, we investigated region-specific hypoperfusion as a driver of neurological dysfunction through correspondence between NIHSS items and CTP. Methods: We included 169 patients with ELVO presenting to Mayo Clinic Rochester or Jacksonville, who had baseline CTP and itemised NIHSS data. Perfusion was quantified as mean transit time using e-CTP (Brainomix Ltd., Oxford, UK) and thresholded to ≥5 s for lesion masking. Voxel-wise lesion-symptom mapping (VLSM) was performed using sparse canonical correlations analysis (Lesymap package, R). Results: Total NIHSS was most strongly predicted by left MCA territory hypoperfusion, corresponding to language-eloquent cortical areas and dominant hemisphere motor tracts (figure 1). Contralateral limb motor deficits (NIHSS 5 and 6) were mainly associated with subcortical and white matter hypoperfusion; there was an additional strong signal for left frontal cortex in language function (NIHSS 9). The remaining NIHSS items were less well localised. Conclusions: Expanding on previous pilot data, our results provide further evidence for the feasibility of hypoperfusion-to-symptom mapping in ELVO. This could allow for more nuanced clinical-imaging mismatch determination, and selection of patients based on specific neurological deficits that may be reversible.

Stroke disproportionately affects racial minorities, and the level to which stroke treatment practices differ across races is understudied. Here, we performed a systematic review of disparities in stroke treatment between racial minorities and White patients. A systematic literature search was performed on PubMed to identify studies published from January 1, 2010, to April 5, 2021 that investigated disparities in access to stroke treatment between racial minorities and White patients. A total of 30 studies were included in the systematic review. White patients were estimated to use emergency medical services at a greater rate (59.8%) than African American (55.6%), Asian (54.7%), and Hispanic patients (53.2%). A greater proportion of White patients (37.4%) were estimated to arrive within 3 hours from onset of stroke symptoms than African American (26.0%) and Hispanic (28.9%) patients. A greater proportion of White patients (2.8%) were estimated to receive tPA (tissue-type plasminogen activator) as compared with African American (2.3%), Hispanic (2.6%), and Asian (2.3%) patients. Rates of utilization of mechanical thrombectomy were also lower in minorities than in the White population. As shown in this review, racial disparities exist at key points along the continuum of stroke care from onset of stroke symptoms to treatment. Beyond patient level factors, these disparities may be attributed to other provider and system level factors within the health care ecosystem.

Introduction : Fetal posterior cerebral artery (FPCA) occlusion is a rare but potentially disabling cause of stroke. While endovascular treatment is established for acute large vessel occlusion (LVO) stroke, FPCA occlusions were excluded from acute ischemic stroke trials. We aim to report the feasibility, safety and outcome of mechanical thrombectomy (MT) in acute FPCA occlusions. Methods : We performed a multi‐center retrospective review of consecutive patients who underwent MT of acute FPCA occlusion. Primary FPCA occlusion was defined as an occlusion that was identified on the pre‐procedure CT angiogram or baseline angiogram whereas a secondary FPCA occlusion was defined as an occlusion that occurred secondary to embolization to a new territory after recanalization of a different LVO. Demographics, clinical presentation, imaging findings, endovascular treatment and outcome were reviewed. Results : There were twenty‐five patients with acute FPCA occlusion who underwent MT, distributed across 14 centers. Median NIHSS on presentation was 16. There were 76% (19/25) of patients who presented with primary FPCA occlusion and 24% (6/25) of patients who had a secondary FPCA occlusion. The configuration of the FPCA was full in 64% patients and partial or “fetal‐type” in 36% of patients. FPCA occlusion was missed on initial CTA in 21% of patients with primary FPCA occlusion (4/19). The site of occlusion was posterior communicating artery in 52%, P2 segment in 40% and P3 in 8% of patients. TICI 2b/3 reperfusion was achieved in 96% of FPCA patients. There were no intra‐procedural complications. At 90 days, 48% (12/25) were functionally independent as defined by mRS≤2. Conclusions : Endovascular treatment of acute FPCA occlusion is safe and technically feasible. A high index of suspicion is important to detect occlusion of the fetal posterior cerebral artery in patients presenting with anterior circulation stroke syndrome and patent anterior circulation.

Background and purpose Cerebral venous sinus thrombosis (CVST) is a rare condition but an important complication of spontaneous intracranial hypotension (SIH). We reviewed our experience of patients with SIH and assessed for the presence of CVST. Methods We reviewed the medical records and imaging studies from our tertiary referral institution, assessing patients with clinically suspected SIH as well as imaging findings of intracranial hypotension. All relevant brain MRIs were reviewed for the presence of brain sag, pachymeningeal enhancement, and CVST. Results Among 563 patients with a clinical diagnosis of SIH, 431 (76%) demonstrated brain sag. In the overall patient cohort, a total of 5 patients had CVST (0.9%) and all 5 of these patients demonstrated findings of brain sag. Of the patients with CVST, 3 had significant complications, including dural arteriovenous fistulas (2 patients) and lobar hemorrhage with seizure (1 patient). Conclusion SIH is a risk factor for the development of CVST. In our review of 563 patients with clinical and/or imaging findings of SIH, 0.9% of patients were diagnosed with CVST and 3 of these patients (60%) had additional severe complications.

Background & Purpose It has been hypothesized that circulating neutrophils have a direct correlation with the composition of emboli in acute ischemic stroke (AIS). The aim of this study is to evaluate the association between neutrophil-lymphocyte ratio (NLR) in peripheral blood and the expression of neutrophil extracellular traps (NETs) within stroke emboli. Methods Consecutive patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) that underwent mechanical thrombectomy (MT) were included. Patients were divided into two groups based on NLR median value. Retrieved thrombi were histologically analyzed using Martius Scarlett Blue (MSB) for main thrombus components including red blood cells (RBCs), white blood cells (WBCs), fibrin and platelet. Immunohistochemistry staining for von Willebrand Factor (vWF) and anti-citrullinated H3 (H3Cit; NETs marker) was also performed. Results Samples from a total of 84 patients were included. The average percentage of RBCs, WBCs, fibrin, platelet, H3Cit, and vWF components in thrombi were 45.1%, 3.5%, 21.8%, 29.6%, 19.7% and 14.8% respectively. When stratifying by NLR group [low (≤3.94) versus high (>3.95)], high NLR group had significantly more WBCs (4.5%), fibrin (24.2%), H3Cit (22.7%) and vWF (17.1%) thrombus fractions compared to low NLR group. Additionally, RBC content (38.8%) was lower in the high NLR group. Conclusions NLR is correlated with the amounts of WBCs, fibrin, NETs and vWF within the thrombi retrieved from AIS patients due to LVO.

Introduction: A common risk factor of chronic, nontraumatic subdural hematoma (SDH) is anticoagulation therapy. Anticoagulation is generally held in patients who develop SDH, but this can lead to thromboembolic events. While prior studies have reported the clinical outcomes of patients with anticoagulation-related SDH, there remains little evidence regarding ongoing anticoagulation treatment. Case Report: We report the management of 2 patients who developed anticoagulation-related SDH and underwent middle meningeal artery (MMA) embolization and successful reinitiation of anticoagulation therapy. In both patients, we conservatively managed anticoagulation with heparin and/or enoxaparin as a bridge to warfarin after MMA embolization. Follow-up computed tomography head revealed interval decrease of SDH and stable neurological status. Conclusions: These cases provide anecdotal evidence of a challenging clinical scenario where there is a necessary indication for therapeutic anticoagulation (ie, venous sinus thrombosis or atrial appendage thrombus) and comorbid SDH. Endovascular MMA embolization may be an effective adjunct therapy for clinical scenarios in patients with SDH and an urgent indication for anticoagulation. Longer follow-up, prospective series, and future randomized clinical trials are needed to objectively assess outcomes in this clinically challenging patient population.