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Background: Diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) has been used to estimate infarct core volume in acute stroke. However, the same and indiscriminate score deduction for punctate or confluent DWI high-intensity lesion might lead to variation in performance. Aims: To develop and evaluate a differential detailed DWI-ASPECTS method in comparison with the conventional DWI-ASPECTS in core infarct volume measurement and clinical outcome prediction. Methods: We retrospectively recruited patients with acute ischemic stroke (AIS) treated with endovascular treatment between April 2013 and October 2019. In differential detailed DWI-ASPECTS, restricted diffusion lesion that was punctate or less than half of a cortical region (M1–M6) would not lead to subtraction of point. A favorable outcome was modified Rankin Scale score ⩽2 at 90 days after stroke onset. Results: Among 298 AIS patients, mean age was 75 years (interquartile range (IQR) 67–82), and 194 patients (65%) were males. Mean infarct core volume was 11 mL (IQR 3–37). Overall, the score by detailed DWI-ASPECTS was significantly higher than conventional DWI-ASPECTS (8 (7–9) vs. 7 (5–9); P < 0.01). The detailed DWI-ASPECTS resulted in a higher correlation coefficient (r) for core infarct volume estimation than the conventional DWI-ASPECTS (r = 0.832 vs. 0.773; P < 0.01). Upon re-classification of those scored ⩽6 in conventional DWI-ASPECTS (n = 134) by detailed DWI-ASPECTS, the rate of favorable outcome in patients with detailed DWI-ASPECTS >6 was significantly higher than those with ⩽6 (29 (48%) vs. 14 (19%); P < 0.01). Conclusions: Detailed DWI-ASPECTS appeared to provide a more accurate infarct core volume measurement and clinical outcome correlation than conventional DWI-ASPECTS among AIS patients treated with endovascular therapy. [ABSTRACT FROM AUTHOR]

The best management for acute basilar artery occlusion (BAO) has increasingly been clarified by recent randomized controlled trials (RCTs). We conducted a systematic review and meta-analysis of RCTs comparing endovascular therapy (EVT) vs best medical management (BMM). We searched PubMed, Embase, the CENTRAL, and ClinicalTrials.gov from January 1, 2000, to November 20, 2022. We included RCTs comparing EVT vs BMM in BAO or bilateral vertebral artery occlusion (VAO). Primary outcome was ambulation (modified Rankin Scale score [mRS] 0–3) at 90 days. Secondary outcomes were independence (mRS 0–2) at 90 days, death by 90 days, and symptomatic intracranial hemorrhage (sICH). Risk ratio (RR) with 95% CI was used as a measure of the association of EVT vs BMM with outcomes. Final analyses included 4 RCTs with 988 patients with BAO or VAO. Pooled results showed that EVT vs BMM was associated with an increased rate of 90-day ambulation (RR 1.54, 95% CI 1.16–2.05), independence (RR 1.83, 1.08–3.08) and a reduced risk of mortality (RR 0.76, 0.65–0.89), but an increased risk of sICH (RR 7.48, 2.27–24.62) and the benefits might be confined to patients with BAO but not patients with VAO. EVT effect was modified by occlusion location with the basilar artery, with greatest benefit for proximal, intermediate benefit for middle, and least benefit for distal occlusions. EVT compared with BMM might be associated with an increased rate of ambulation, independence and survival but with an increased risk of sICH in patients with acute BAO. [ABSTRACT FROM AUTHOR]

Basilar artery occlusion is a relatively uncommon but neurologically devastating condition. If revascularization is not achieved, the potential for death and disability is substantial. During the last several years, there have been positive endovascular stroke trials for thetreatment of large vessel occlusion; however, all of them excluded patients with basilarartery occlusion. The currenttreatment of basilarartery occlusion is still founded on small observational studies or meta-analyses. As case selection for revascularization andtreatment protocols often varywidelyacross institutions, sample sizes remain limited. In this article, we aim to review some of the larger observational studies in stroke due to basilar artery occlusion, considering potential treatment strategies and resultant outcomes. [ABSTRACT FROM AUTHOR]

Collateral circulation plays a pivotal role in acute ischemic stroke due to large vessel occlusion (LVO) and may be affected by multiple variables during sedation for endovascular therapy (EVT). We conducted detailed analyses of the GOLIATH trial to identify predictors of collateral circulation grade and infarct growth. We also modified the ASITN collateral grading scale and sought to determine its impact on clinical outcome and infarct growth. Multivariable analysis was used to identify predictors of collaterals and infarct growth. Ordinal analysis demonstrated nominal, but non-significant association between modified ASITN scale and infarct growth. Among all analyzed baseline clinical and procedural variables, the most significant predictors of infarct growth at 24 h were phenylephrine dose (estimate 6.78; p = 0.014) and baseline infarct volume (estimate 0.93; p = 0.03). The most significant predictors of worse collateral grade were mean arterial pressure (MAP) <70 mmHg (OR 0.35; p = 0.048) and baseline infarct volume (OR 0.96; p = 0.003). Hypotension during sedation for EVT for LVO negatively impacts collateral circulation, while higher pressor dose is a strong predictor of infarct growth. Avoidance of anesthesia-induced hypotension and consequent need for pressor therapy may prevent collateral failure and minimize infarct growth. [ABSTRACT FROM AUTHOR]

Comorbidities are a hallmark of stroke that both increase the incidence of stroke and worsen outcome. Hypertension is prevalent in the stroke population and the most important modifiable risk factor for stroke. Hypertensive disorders promote stroke through increased shear stress, endothelial dysfunction, and large artery stiffness that transmits pulsatile flow to the cerebral microcirculation. Hypertension also promotes cerebral small vessel disease through several mechanisms, including hypoperfusion, diminished autoregulatory capacity and localized increase in blood–brain barrier permeability. Preeclampsia, a hypertensive disorder of pregnancy, also increases the risk of stroke 4–5-fold compared to normal pregnancy that predisposes women to early-onset cognitive impairment. In this review, we highlight how comorbidities and concomitant disorders are not only risk factors for ischemic stroke, but alter the response to acute ischemia. We focus on hypertension as a comorbidity and its effects on the cerebral circulation that alters the pathophysiology of ischemic stroke and should be considered in guiding future therapeutic strategies. [ABSTRACT FROM AUTHOR]

Precision cerebrovascular health or individualized long-term preservation of the brain and associated blood vessels, is predicated on understanding, diagnosing, and tailoring therapies for people at risk of ischemic injury associated with stroke and vascular dementia. The associated imaging patterns are sculpted by the protective effect of the collaterome, the innate compensatory ability of the brain and vasculature to offset hypoperfusion when antegrade or normal arterial inflow pathways are compromised. Theranostics or rational and synchronous use of diagnostic studies in tandem with specific therapies to optimally guide patient outcomes in ischemic brain disorders may capitalize on the pivotal role of the collaterome. Understanding the functional impact of the collaterome across populations of individuals would advance translational science on the brain, while questions with immediate clinical implications may be prioritized. Big data and systematic analyses are necessary to develop normative standards, multimodal imaging atlases, and delineation of specific patterns to guide clinical management. Large-scale, systematic imaging analyses of the collaterome provide a platform for translational work on cerebral collateral circulation and hemodynamics and a theranostic framework with direct clinical implications. This article frames incipient research objectives to guide precision stroke medicine in coming years, building upon the collaterome concept in brain health. [ABSTRACT FROM AUTHOR]

Neuroimaging provides detailed information regarding the hemodynamic, metabolic and cellular parameters of cerebral ischemia (CI). Although providing just a snapshot in time, it assists in delineating the boundaries and extent of this continually evolving process, from the irreversibly damaged infarct core to the penumbral tissue, where salvage via reperfusion has been the focus of acute stroke therapies. Beyond the extent of the ischemic lesion, neuroimaging elucidates the topography and underlying mechanism of CI. Finally, based on the pathophysiological information, neuroimaging assists in the selection of optimal therapeutic strategies, from hyperacute to chronic phases of CI. Here we review different neuroimaging techniques by which the pathophysiology of cerebral ischemia can be delineated. This article is part of the Special Issue entitled ‘Cerebral Ischemia’. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions Ischemic stroke is a significant cause of disability and death worldwide. Randomized clinical trials (RCTs) are important in changing guidelines and treatment strategies. This study aimed to analyze the progress of RCTs in ischemic stroke and to guide future research directions.Ischemic stroke‐related RCT articles were identified in six high‐impact medical journals using the Web of Science Core Collection database. Google Scholar was used to check whether relevant articles were included in the guidelines. The characteristics of these articles were analyzed and future research hotspots were predicted.389 relevant articles were included in the analysis. The number of articles increased rapidly from 1972 to 2022, from 5 (1.3%; 1972–1982) to 208 (53.5%; 2013–2022) articles. 338 (86.9%) articles were included in relevant guidelines. According to corresponding author location, Europe was the source of the highest number of publications (183; 47.0%), followed by the Americas (152; 39.1%) and the Western Pacific (54; 13.9%). The number of publications steadily increased over time in the USA, England, Canada, Australia, Germany, and France, and surged in China and Spain, especially in the last 5 years. In recent years, endovascular therapy has accounted for the majority of ischemic stroke‐related RCT articles.Numerous RCTs related to ischemic stroke have been conducted in recent decades, and both the number of articles and their contribution to guideline updates are increasing. Also, a shift in research topics was observed. However, great regional imbalances in this research exist, calling for more research to be conducted in specific regions to promote the generalizability of trial conclusions. [ABSTRACT FROM AUTHOR]

Background The purpose of this study was to determine the performance of computed tomography angiography (CTA) by using a scoring system to predict anterograde and collateral blood flow status in patients with symptomatic middle cerebral artery (MCA) stenosis with use of conventional angiography as standard reference. Methods We retrospectively identified all consecutive patients with unilateral symptomatic MCA stenosis in our center who underwent conventional angiography and CTA within 1 month. The anterograde and collateral blood flow (AnCo) scoring system consisted of anterograde score (AnS) and collateral score (CoS). Evaluation of the CTA images was done independently by two readers, based on the AnCo scoring system. The conventional angiography was assessed by using the Thrombolysis in Cerebral Infarction (TICI) and American Society of Interventional and Therapeutic Neuroradiology (ASITN/SIR) scoring system to determine the status of anterograde and collateral blood flow. Diagnostic performance of AnCo was evaluated by using the area under the receiver operating characteristic (ROC) curve. Results A total of 61 patients were included in the analysis with mean age of 53.4 ± 11.0 years. AnS demonstrated a strong correlation with TICI with statistical significance (r = 0.786; p < 0.001). CoS had a modest yet statistically significant correlation with ASITN/SIR (r = 0.574; p < 0.001). The ROC curve analysis for AnS demonstrated an area under the curve (AUC) of 0.894 (p < 0.001) and the ROC curve analysis for CoS showed an AUC of 0.824 (p < 0.001). Conclusions CTA was a potential method to evaluate anterograde and collateral blood flow status in patients with symptomatic unilateral MCA stenosis. [ABSTRACT FROM AUTHOR]

Collaterals 2016 (third International Symposium on Collaterals to the Brain) was a multidisciplinary scientific conference focused on collateral circulation in acute ischemic stroke. Decisive challenges include generalizability of optimal triage and selection paradigms based on collateral status for definitive treatment of acute ischemic stroke, rapid dissemination of expert methods, and the urgent need to leverage networking opportunities for stroke science related to the hemodynamics of collaterals. The collaterome, or individual capacity to offset ischemia in the brain, and determination of a favorable collateral profile have become pivotal factors in consideration of the precision medicine of stroke decisionmaking. The conference convened over 50 invited faculty from around the world to connect on-site participants at a state-of-the-art facility with remote audiences in more than 22 countries and regions. The 2½-day program was structured into 40-min sessions devoted to key issues in translating the collaterome in acute stroke therapy across the globe. This unique forum of expertise emphasized the timely impact of collaterals on a monumental scale, encouraging maximal participation, rapid diffusion and added value of a diverse networking resource. The meeting format established a model geographical framework and innovative videoconferencing platform for future scientific conferences. [ABSTRACT FROM AUTHOR]

The prevalence of obesity, diabetes, and metabolic syndrome has increased globally. These epidemiologic changes are likely responsible for a rise in stroke incidence among young adults, despite declining stroke incidence rates in the elderly. In this review, the authors summarize the current understanding of the epidemiology and pathophysiology of stroke associated with obesity, diabetes, and metabolic syndrome. [ABSTRACT FROM AUTHOR]

Objective: To determine the association in amount of daily coffee consumption with incidence of stroke in a broad cohort, considering other vascular risk factors. Methods: We utilized the Third National Health and Nutrition Examination Survey (1988–1994; NHANES III) data on participants aged ≥17 years old to examine coffee consumption and stroke. Multivariate logistic regression models related the amount of coffee use reported in a food frequency questionnaire with stroke, controlling for other vascular risk factors. Results: Of 33 994 NHANES III subjects, coffee consumption and stroke data in adults ≥17 years old were available in 19 994. Daily coffee consumption ranged from 0 to 20 (median 1) cups and 644 (3.2%) participants had a stroke diagnosed by a physician. Coffee intake varied with age, gender, and ethnicity (P < 0.001). Interestingly, heart failure, diabetes, and hypertension were less frequent, and high cholesterol more frequent in those consuming ≥3 cups per day (P < 0.001). Smoking was more frequent in all coffee drinkers (P < 0.0001). Multivariate analyses revealed an independent effect of heavier coffee consumption (≥3 cups/day) on reduced stroke (OR 0.44, 95% CI 0.22–0.87,P < 0.02) in healthy subjects that was attenuated by vascular risk factors (OR 0.78, 95% CI 0.58–1.07,P ≈ 0.12). Conclusion: Heavier daily coffee consumption is associated with decreased stroke prevalence, despite smoking tendency in heavy coffee drinkers. [ABSTRACT FROM AUTHOR]

Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and Tmax, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. [ABSTRACT FROM AUTHOR]

Imaging of stroke and neurovascular disorders has profoundly enhanced clinical practice and related research during the last 40 years since the introduction of computed tomography (CT) and magnetic resonance imaging (MRI) enabled mapping of the brain. We highlight recent advances in neurovascular imaging. We describe how the convergence of readily available data and new clinical trial paradigms will recast our methods for studying the neurovascular patient. The application of a precision medicine approach to the collaterome, a comprehensive synthesis of neurovascular pathophysiology, will entail novel methods for clinical trial randomization, collection of routine and clinical trial imaging results, data archiving, and analysis. [ABSTRACT FROM AUTHOR]

The article offers information on the management of acute stroke that is caused due to ischemia or hemorrhage in the brain. It mentions the application of big data for precision medicine of stroke in neurocritical care. It also discusses a study published in the issue regarding the outcome of stroke patients based on longitudinal data.

The author comments on a study by K. Malhotra and colleagues, published within the issue, on the therapeutic strategies for acute ischemic stroke patients taking apixaban. He discusses the advances in stroke prevention for atrial fibrillation according to study authors, the clinical dilemma posed by the authors of an acute ischemic stroke developing while the patient is taking apixaban, and the importance of data in the future of precision medicine in stroke and the realization of theranostics.

ABSTRACT Ischemic stroke remains a leading cause of death and disability worldwide. Various endovascular trials have addressed clinical outcomes without elucidating the impact of imaging studies in patient selection. The success of recent endovascular trials was bolstered by the use of advanced imaging techniques for optimal selection of reperfusion candidates. This seminal juncture in the history of stroke trials warrants further consideration on the use of imaging to guide future refinements in the treatment of acute stroke. In this article, we systematically review the imaging methodology and key facets used in all published endovascular stroke trials to date, discuss the success of recent trials using latest advanced imaging techniques and focus on the importance of imaging studies for future patient selection. [ABSTRACT FROM AUTHOR]

Background Collaterals may affect revascularization, ischemic severity, and clinical outcomes in acute stroke owing to internal carotid artery (ICA) occlusion. Objective To examine the hypothesis that morphology of occlusive thrombus and collateral flow patterns may influence the outcome of ICA occlusions after mechanical thrombectomy. Methods Pooled analyses of ICA occlusions in the MERCI and Multi-MERCI trials employed central angiography review readings to categorize lesions as I, L, or T clots and functional lesions based on collateral flow patterns. Demographic variables, procedural details, and clinical outcomes were compared across ICA lesion types. Results A total of 72 subjects (mean age 67 years (SD 16), 51% female, median National Institutes of Health Stroke Scale 20 (range 8-35)) were included, with 90-day modified Rankin score ≤2 in 28% and 51% mortality. Clots were categorized as an I lesion in 9/72 (12.5%), L lesion in 12/72 (16.7%), and T lesion in 51/72 (70.8%). Based on collateral flow patterns, cases were categorized as having a functional I lesion in 7/72 (9.7%), functional L in 38/72 (52.8%), and functional T in only 27/72 (37.5%). Multivariate analyses showed that a functional T lesion, with insufficient collateral flow to ipsilateral anterior cerebral arteries via the contralateral ICA, was a strong predictor of both revascularization success and subsequent clinical outcomes. Conclusions Collateral flow patterns distinguish the nature and impact of ICA occlusions on expected revascularization and subsequent clinical outcomes in acute ischemic stroke. The nomenclature of terminal ICA occlusions introduced here (carotid I's, L's, and T's) may enhance future endovascular trials targeting such proximal occlusions. Trial registration number NCT00318071 (http:// clinicaltrials.gov). MERCI was not registered because enrollment began before July 1, 2005. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the relationship between hyperperfusion and hemorrhagic transformation (HT) in acute ischemic stroke (AIS). Pseudo-continuous arterial spin labeling (ASL) with background suppressed 3D GRASE was performed during routine clinical magnetic resonance imaging (MRI) on AIS patients at various time points. Arterial spin labeling cerebral blood flow (CBF) maps were visually inspected for the presence of hyperperfusion. Hemorrhagic transformation was followed during hospitalization and was graded on gradient recalled echo (GRE) scans into hemorrhagic infarction (HI) and parenchymal hematoma (PH). A total of 361 ASL scans were collected from 221 consecutive patients with middle cerebral artery stroke from May 2010 to September 2013. Hyperperfusion was more frequently detected posttreatment (odds ratio (OR)=4.8, 95% confidence interval (CI) 2.5 to 8.9, P<0.001) and with high National Institutes of Health Stroke Scale (NIHSS) scores at admission (P<0.001). There was a significant association between having hyperperfusion at any time point and HT (OR=3.5, 95% CI 2.0 to 6.3, P<0.001). There was a positive relationship between the grade of HT and time-hyperperfusion with the Spearman's rank correlation of 0.44 (P=0.003). Arterial spin labeling hyperperfusion may provide an imaging marker of HT, which may guide the management of AIS patients post tissue-type plasminogen activator (tPA) and/or endovascular treatments. Late hyperperfusion should be given more attention to prevent high-grade HT. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND AND PURPOSE Fractional flow may identify hemodynamic effects and ischemic risk beyond percent stenosis of an artery. We hypothesized that diminished TOF-MRA signal intensity distal to an intracranial stenosis predicts stroke risk. METHODS TOF-MRA was acquired prospectively in the SONIA-WASID trials. The distal/proximal signal intensity ratio (SIR) was calculated from 3 mm regions of interest, blinded to outcome. Univariate and multivariate analyses included clinical variables, SIR, and invasive angiography measures to identify predictors for risk of stroke in the territory. RESULTS 189 patients with 50-99% symptomatic intracranial stenosis in SONIA-WASID had TOF-MRA available. In univariate analysis, the hazard ratio (HR) for stroke in the territory of the symptomatic artery with SIR < .9 was 5.2 (1.8, 15.3; P < .001) as compared to SIR ≥ .9. Multivariate analysis correcting for baseline systolic blood pressure, LDL, centrally measured percent stenosis, recency of symptoms, TICI and downstream collaterals, the HR for SIR < .9 was 10.9 (2.0, 58.9; P < .001). In those with <70% stenosis, a SIR < .9 maintained a significant association with recurrent stroke in the territory ( P = .006), with a 2-year event rate of 17.3%. CONCLUSIONS Fractional flow assessed by TOF-MRA SIR may be a useful noninvasive tool to identify high-risk intracranial lesions. CLINICAL TRIAL REGISTRATION-URL This trial was not registered because enrollment began prior to July 1, 2005. [ABSTRACT FROM AUTHOR]

ABSTRACT Cerebral microbleeds (CMB) on gradient-recalled echo (GRE) magnetic resonance imaging (MRI) are rarely seen in children, yet have been described following vascular procedures in adults. Extracorporeal membrane oxygenation (ECMO) has been associated with vascular injury and neurological events in children, but there have been no reports to date of GRE MRI findings in children treated with ECMO. We reviewed MRI scans for all vascular neurology consultations in children treated with ECMO at an academic medical center over a 5-year period. In 6 of 12 cases, GRE was acquired as others were unstable or had contraindications to MRI. All 6 of 6 (100%) GRE cases (mean age 2.1 years, 7 female, 5 male) demonstrated CMB. CMB were multiple (>3 lesions), situated in cortical or lobar regions, with a striking predominance (5/6 cases) for the right carotid distribution. Other than CMB, no cases demonstrated intracranial hemorrhage. CMB may be noted on GRE MRI after ECMO and may reflect vascular damage from gaseous emboli. [ABSTRACT FROM AUTHOR]

Multimodal CT/MRI has dramatically changed the approach to ischemic stroke management, as noninvasive CT/MRI images detail brain tissue or parenchyma, angiography or vessel status, and collateral perfusion or blood flow in regions of the brain vulnerable to ischemic injury. Such snapshots of the dynamic process of cerebral ischemia may be used to gauge reversibility and therapeutic opportunities. Treatment of acute stroke may be rapidly tailored to clinical scenarios based on imaging correlation of ischemia, vessel status, and perfusion. Serial or repeated imaging from the initial presentation to later stages of the hospital course may illustrate infarct growth, persisting occlusion, reocclusion, recanalization, reperfusion, and hemorrhagic transformation. From acute stroke to rehabilitation phases and subsequent prevention, multimodal CT/MRI has emerged as a key tool to track the process of stroke and the impact of our therapeutic interventions. [ABSTRACT FROM AUTHOR]

Collateral circulation in intracranial atherosclerosis has never been systematically characterized. We investigated collaterals in a multicenter trial of symptomatic intracranial atherosclerotic disease. Baseline angiography was reviewed for information on collaterals in stenoses of the internal carotid, middle cerebral, vertebral, and basilar arteries. A battery of angiographic scales was utilized to evaluate lesion site, arterial patency, antegrade flow, downstream territorial perfusion, and collateral circulation, blinded to all other data. Collateral circulation was adequately available for analysis in 287/569 (50%) subjects with proximal arterial stenoses ranging from 50% to 99%. Extent of collaterals was absent or none in 69%, slow or minimal in 10%, more rapid, yet incomplete perfusion of territory in 7%, complete but delayed perfusion in 11%, and rapid, complete collateral perfusion in 4%. Extent of collateral flow correlated with percentage of stenosis (P<0.0001), with more severe stenoses exhibiting greater compensation via collaterals. Overall, collateral grade increased with diminished antegrade flow across the lesion (thrombolysis in myocardial ischemia) and resultant downstream perfusion (thrombolysis in cerebral infarction) (both P<0.001). Our findings provide the initial detailed description of collaterals across a variety of stenoses, suggesting that collateral perfusion is a pivotal component in pathophysiology of intracranial atherosclerosis and implicating the need for further evaluation in ongoing studies. [ABSTRACT FROM AUTHOR]

Objective: We recently demonstrated that the preprocedural magnetic resonance imaging (MRI) pattern of deep middle cerebral artery (MCA) territory injury predicts poor prognosis. We postulate that the structures of the deep MCA field are particularly vulnerable to hemorrhagic transformation (HT) following reperfusion. Methods: We reviewed all cases of acute occlusions involving the M1 segment of the MCA with diffusion restriction of at least 50% of the deep MCA field on MRI (M1a pattern) that underwent endovascular therapy. We compared those with and without recanalization in regards to HT and disability on discharge. Results: Thirty-five patients met inclusion criteria. The recanalized M1a group (n = 27) had higher rates of HT (67% vs. 25%, P = 0.05) and a trend toward more parenchymal HT (37% vs. 0%, P = 0.07) and symptomatic HT (22% vs. 0%, P = 0.12) than those M1a patients who failed to recanalize (n = 8). Clinical improvement in the National Institutes of Health Stroke Scale by discharge was better in the survivors of the recanalized group. Conclusions: Among patients with the preintervention M1a MRI pattern of advanced basal ganglionic injury, successful recanalization predicts a higher risk of HT but better outcome. [Copyright &y& Elsevier]

Bleeding into the brain or adjacent structures is one of the most devastating neurological conditions, incurring tremendous emotional, financial, and societal costs. Imaging is essential to differentiate variants of hemorrhage, as the clinical features may be insufficient. A comprehensive approach to hemorrhage therefore relies on imaging to disclose pathophysiology, elucidate mechanisms, and thereby open further avenues to effective treatment. Hemorrhage patterns from superficial to deep locations in the brain are surveyed in this work, noting myriad potential causes and the influential pathophysiology of arterial ischemia, venous hypertension, and microvascular dysfunction. Recent progress of imaging studies and novel techniques to evaluate hemorrhage are explored. For decades, only computed tomography was available to define a hematoma without corroborating evidence of other pathology whereas multimodal computed tomography and magnetic resonance imaging, including noninvasive imaging of brain tissue, vessels, and perfusion, have now radically altered clinical practice. Imaging of the blood-brain barrier, cerebral microbleeds, coexistent ischemia, associated vascular lesions, and markers of hemorrhage expansion is possible with routine protocols akin to diagnostic strategies for ischemic stroke. Imaging applications for hemorrhagic transformation, venous thrombosis, and microvascular disorders are considered with a perspective that balances concern for hemorrhage with prevention of ischemia as these processes are often intertwined and clinical conundrums arise. Imminent imaging advances are anticipated with increased use of detailed imaging for hemorrhage and overlap with cerebral ischemia. Numerous questions abound regarding optimal management of hemorrhage and definitive treatments are lacking, yet imaging of pivotal pathophysiology offers tremendous opportunity for future progress in combating this debilitating condition. Ann Neurol 2010;68:581-592 [ABSTRACT FROM AUTHOR]

Abstract: Background and purpose: To evaluate the strength of the in vivo evidence of relationships between flavonoids and risk of stroke. Methods: We reviewed the literature more broadly for flavonoids and stroke and conducted an evidence-based review of original publication experiments on tea or tea components on induced coronary occlusion in animal models and on the observational epidemiology on stroke and either tea or flavonoids in man. Each of the studies was evaluated by two independent reviewers. The evidence in total was compared with the Bradford Hill and Stroke Therapy Academic Industry Roundtable (STAIR) [1] Abbreviations Used: STAIR, Stroke Therapy Academic Industry Roundtable; EGCG, epigallocatechin gallate; MCAO, middle cerebral artery occlusion; SHRSP rats, Sprague–Dawley or Wistar rats, Mongolian gerbil, ddY mice, or spontaneously hypertensive stroke-prone rats 1 quality-assessment criteria . Results: The search of epidemiologic publications revealed 7 cohort studies on flavonoid intake and stroke and 7 cohort studies and 3 case control studies on tea and stroke. In studies of tea there was a consistent protective effect. However, the epidemiologic research on flavonoids and stroke was much less consistent. Eleven animal experiments were identified that examined tea or tea components and stroke relevant sequelae, eight of which reported on infarct volume. All studies demonstrated reduced infarct volumes in animals exposed either to tea extracts, theanine or tea catechins prior to or shortly after reperfusion. Conclusions: Hill’s criteria of causality are largely met in the case of tea and stroke. A high level of consistency across preclinical studies, of the effect of tea components as single agents effective in reducing stroke volume after middle cerebral artery occlusion, is noted in all rodent models (rat, mouse, and gerbil). Reductions in infarct volume are seen with both tea extracts consumed orally and tea components introduced intra-peritoneally. Observational epidemiology supports this finding in man for tea – the studies are consistent across countries and type of tea and the relative risks are moderately strong. That is not the case for the body of evidence on flavonoid intakes and stroke. [Copyright &y& Elsevier]

BACKGROUND AND PURPOSE Collaterals may compensate for reduced blood flow in acute ischemic stroke, yet endurance and quality of collateral perfusion may vary. Collateral sustenance of penumbra may falter after initial recruitment, resulting in progressive ischemia and clinical deficits. Delayed collateral failure may extend the time window for revascularization, even after failed intravenous thrombolysis. CASE DESCRIPTION A 76-year-old woman returned to normal from National Institutes of Health Stroke Scale (NIHSS) score of 18 following intravenous thrombolysis, despite persistent occlusion of the left middle cerebral artery. Subsequent deterioration was successfully reversed with mechanical thrombectomy almost 14 hours after symptom onset. CONCLUSIONS Early clinical improvement or deterioration may reflect collateral perfusion, not necessarily recanalization or reocclusion. The definition of collateral failure must incorporate the expected role and endurance of collaterals. Further investigation of collateral pathophysiology may reveal predictive clinical or imaging features and disclose collateral therapeutic approaches to augment revascularization. J Neuroimaging 2010;20:78-82. [ABSTRACT FROM AUTHOR]

Envisioning the future of stroke appears daunting considering the milestones already achieved in stroke imaging. A historical perspective on the developments in stroke care provides a striking narrative of how imaging has transformed diagnosis, therapy, and prognosis of cerebrovascular disorders. Multimodal imaging techniques such as CT and MRI, incorporating parenchymal depictions, illustration of the vasculature, and perfusion data, can provide a wealth of information regarding ischemic pathophysiology. Key elements of ischemic pathophysiology depicted with imaging include vascular occlusion, compensatory collateral flow, resultant hemodynamic conditions that reflect these sources of blood flow, and the neurovascular injury that ensues. The mantra of 'time is brain' has been perpetuated, but this does not provide an entirely accurate reflection of ischemic pathophysiology and imaging insight shows far more than time alone. Maximizing the potential of perfusion imaging will continue to expand the nascent concept that cerebral ischemia may be completely reversible in certain scenarios. Novel modalities provide a fertile ground for discovery of therapeutic targets and the potential to assess effects of promising strategies. Beyond clinical trials, imaging has become a requisite component of the neurological examination enabling tailored stroke therapy with the use of detailed neuroimaging modalities. In this first article on ischemia, the focus is on the most recent imaging advances and exploring aspects of cerebral ischemia where imaging may yield additional therapeutic strategies. A subsequent article will review recent and anticipated imaging advances in hemorrhage. These thematic overviews underscore that imaging will undoubtedly continue to dramatically shape the future of stroke. Ann Neurol 2009;66:574-590 [ABSTRACT FROM AUTHOR]

BACKGROUND Reperfusion of penumbral tissue is a promising strategy for treatment of acute cerebral ischemia more than 3 hours from symptom onset. However, there has been only sparse direct evidence that reperfusion after 3 hours prevents infarct growth. METHODS We analyzed clinical and serial magnetic resonance imaging (MRI) data on patients who received endovascular recanalization therapy 3-12 hours after last known well time. Multimodal MRIs were acquired pretreatment, early (1-20 hours), and late (2-7 days) after treatment. Degree of recanalization was assessed on end of procedure catheter angiogram, degree of reperfusion on early posttreatment perfusion MRI, and infarct growth by analysis of diffusion lesion volumes on pretreatment and late MRIs. RESULTS Twenty-seven (12 men, 15 women) underwent endovascular recanalization procedures at 6.0 ± 2.1 hours (range, 3.0-11.5 hours) after last known well time. Immediate posttreatment perfusion lesion (Tmax ≥4 seconds) volume correlated strongly with infarct growth ( r= .951, P < .001), exceeding the correlations of vessel recanalization score ( r=−.198, P= .446) and pretreatment diffusion-perfusion mismatch volume ( r= .518, P= .033). Without reperfusion, enlargement of DWI lesion volume was observed in all patients, and extent of enlargement depended on volume of immediate posttreatment perfusion defects. CONCLUSION Our data indicate that posttreatment reperfusion is the major determinant of threatened tissue outcome, and suggest reperfusion even after 3 hours of symptom onset can alter tissue fate over a wide range of mismatch volumes. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE Hypoxia is commonly known to target neuronal cell bodies. Although myelin is a non-infrequent target, posthypoxic demyelination is a rarely described entity. We describe the case of a man who developed neurogenic bladder following a motor vehicle accident. CASE REPORT Following a severe motor-vehicle accident involving massive blood loss, a 46-year-old man developed urinary urgency requiring catheterization, with hyperactive reflexes and bilateral Babinski signs on exam. RESULTS Magnetic resonance imaging of the brain and cervical cord revealed diffuse, isolated white matter signal abnormality in a symmetric, confluent distribution, extending inferiorly into the spinal cord, with changes consistent with bilateral Wallerian degeneration. Serologic and CSF evaluations were normal. CONCLUSIONS Unlike previous reports of hypoxic-ischemic demyelination, our patient lacked any cortical abnormalities, presumably due to isolated white matter changes. This report alerts physicians to the possibility of hypoxic-ischemic demyelination due to global hypoxia-ischemia as an etiologic factor for neurogenic bladder. [ABSTRACT FROM AUTHOR]

Objective Methods Results Interpretation We aimed to assess the impact of time to endovascular thrombectomy (EVT) on clinical outcomes in the DAWN trial, while also exploring the potential effect modification of mode of stroke onset on this relationship.The association between every 1‐h treatment delay with 90‐day functional independence (modified Rankin Scale [mRS] score 0–2), symptomatic intracranial hemorrhage, and 90‐day mortality was explored in the overall population and in three modes of onset subgroups (wake‐up vs. witnessed vs. unwitnessed).Out of the 205 patients, 98 (47.8%) and 107 (52.2%) presented in the 6 to 12 hours and 12 to 24 hours time window, respectively. Considering all three modes of onset together, there was no statistically significant association between time last seen well to randomization with either functional independence or mortality at 90 days in either the endovascular thrombectomy (mRS 0–2 1‐hour delay OR 1.07; 95% CI 0.93–1.24; mRS 6 OR 0.84; 95% CI 0.65–1.03) or medical management (mRS 0–2 1‐hour delay OR 0.98; 95% CI 0.80–1.14; mRS 6 1‐hour delay OR 0.94; 95% CI 0.79–1.09) groups. Moreover, there was no significant interaction between treatment effect and time (p = 0.439 and p = 0.421 for mRS 0–2 and 6, respectively). However, within the thrombectomy group, the models that tested the association between time last seen well to successful reperfusion (modified Treatment in Cerebral Infarction ≥2b) and 90‐day functional independence showed a significant interaction with mode of presentation (p = 0.013). This appeared to be driven by a nominally positive slope for both witnessed and unwitnessed strokes versus a significantly (p = 0.018) negative slope in wake‐up patients. There was no association between treatment times and symptomatic intracranial hemorrhage.Mode of onset modifies the effect of time to reperfusion on thrombectomy outcomes, and should be considered when exploring different treatment paradigms in the extended window. ANN NEUROL 2024 [ABSTRACT FROM AUTHOR]

Background and purpose: The value of intravenous thrombolysis (IVT) in eligible tandem lesion patients undergoing endovascular treatment (EVT) is unknown. We investigated treatment effect heterogeneity of EVT + IVT versus EVT‐only in tandem lesion patients. Additional analyses were performed for patients undergoing emergent internal carotid artery (ICA) stenting. Methods: SWIFT DIRECT randomized IVT‐eligible patients to either EVT + IVT or EVT‐only. Primary outcome was 90‐day functional independence (modified Rankin Scale score 0–2) after the index event. Secondary endpoints were reperfusion success, 24 h intracranial hemorrhage rate, and 90‐day all‐cause mortality. Interaction models were fitted for all predefined outcomes. Results: Among 408 included patients, 63 (15.4%) had a tandem lesion and 33 (52.4%) received IVT. In patients with tandem lesions, 20 had undergone emergent ICA stenting (EVT + IVT: 9/33, 27.3%; EVT: 11/30, 36.7%). Tandem lesion did not show treatment effect modification of IVT on rates of functional independence (tandem lesion EVT + IVT vs. EVT: 63.6% vs. 46.7%, non‐tandem lesion EVT + IVT vs. EVT: 65.6% vs. 58.2%; p for interaction = 0.77). IVT also did not increase the risk of intracranial hemorrhage among tandem lesion patients (tandem lesion EVT + IVT vs. EVT: 34.4% vs. 46.7%, non‐tandem lesion EVT + IVT vs. EVT: 33.5% vs. 26.3%; p for interaction = 0.15). No heterogeneity was noted for other endpoints (p for interaction > 0.05). Conclusions: No treatment effect heterogeneity of EVT + IVT versus EVT‐only was observed among tandem lesion patients. Administering IVT in patients with anticipated emergent ICA stenting seems safe, and the latter should not be a factor to consider when deciding to administer IVT before EVT. [ABSTRACT FROM AUTHOR]

The effect of arterial tortuosity on intracranial atherosclerosis (ICAS) is not well understood. This study aimed to evaluate the effect of global intracranial arterial tortuosity on intracranial atherosclerotic burden in patients with ischemic stroke. We included patients with acute ischemic stroke who underwent magnetic resonance angiography (MRA) and classified them into three groups according to the ICAS burden. Global tortuosity index (GTI) was defined as the standardized mean curvature of the entire intracranial arteries, measured by in-house vessel analysis software. Of the 516 patients included, 274 patients had no ICAS, 140 patients had a low ICAS burden, and 102 patients had a high ICAS burden. GTI increased with higher ICAS burden. After adjustment for age, sex, vascular risk factors, and standardized mean arterial area, GTI was independently associated with ICAS burden (adjusted odds ratio [adjusted OR] 1.33; 95% confidence interval [CI] 1.09–1.62). The degree of association increased when the arterial tortuosity was analyzed limited to the basal arteries (adjusted OR 1.48; 95% CI 1.22–1.81). We demonstrated that GTI is associated with ICAS burden in patients with ischemic stroke, suggesting a role for global arterial tortuosity in ICAS. [ABSTRACT FROM AUTHOR]

Background: The clinical efficacy of mechanical thrombectomy has been unequivocally demonstrated in multiple randomized clinical trials. However, these studies were performed in carefully selected centers and utilized strict inclusion criteria. Aim: We aimed to assess the clinical effectiveness of mechanical thrombectomy in a prospective registry. Methods: A total of 2008 patients from 76 sites across 12 countries were enrolled in a prospective open-label mechanical thrombectomy registry. Patients were categorized into the corresponding cohorts of the SWIFT-Prime, DAWN, and DEFUSE 3 trials according to the basic demographic and clinical criteria without considering specific parenchymal imaging findings. Baseline and outcome variables were compared across the corresponding groups. Results: As compared to the treated patients in the actual trials, registry-derived patients tended to be younger and had lower baseline ASPECTS. In addition, time to treatment was earlier and the use of intravenous tissue plasminogen activator (IV-tPA) and general anesthesia were higher in DAWN- and DEFUSE-3 registry derived patients versus their corresponding trials. Reperfusion rates were higher in the registry patients. The rates of 90-day good outcome (mRS0-2) in registry-derived patients were comparable to those of the patients treated in the corresponding randomized clinical trials (SWIFT-Prime, 64.5% vs. 60.2%; DAWN, 50.4% vs. 48.6%; Beyond-DAWN: 52.4% vs. 48.6%; DEFUSE 3, 52% vs. 44.6%, respectively; all P > 0.05). Registry-derived patients had significant less disability than the corresponding randomized clinical trial controls (ordinal modified Rankin Scale (mRS) shift odds ratio (OR), P < 0.05 for all). Conclusion: Our study provides favorable generalizability data for the safety and efficacy of thrombectomy in the "real-world" setting and supports that patients may be safely treated outside the constraints of randomized clinical trials. [ABSTRACT FROM AUTHOR]

The author reflects on trials and research on acute ischemic stroke. As work in neuroprotection has achieved nothing significant, and the number of publications analyzing the failure of neuroprotection surpassed the reports on successful clinical trial, the author calls for researchers to consider blood flow or hemodynamic variables in stroke. He believes that understanding blood flow in acute arterial occlusion underlies the success of any therapeutic approach to acute ischemic stroke.

Purpose: Optimal imaging modalities to select patients for endovascular thrombectomy (EVT) in the late window of acute ischemic stroke due to large vessel occlusions (AIS-LVO) are not known. We conducted a systematic review comparing outcomes of patients selected by non-contrast computed tomography (NCCT)/CT angiography (CTA) vs. those selected by CT perfusion (CTP) or magnetic resonance imaging (MRI) for EVT in these patients.We searched PUBMED, EMBASE, and the Cochrane Library from January 1, 2000, to July 15, 2023, to identify studies comparing outcomes of patients selected for EVT by NCCT/CTA vs. CTP or MRI in the late time window for AIS-LVO. Primary outcome was independence (mRS 0–2) at 90 days or discharge. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. We pooled data across studies based on an inverse variance method.Six cohort studies with 4208 patients were included. Pooled results showed no significant difference in the rate of independence at 90 days or discharge (RR 0.96, 95% CI 0.88–1.03) and sICH (RR 1.26, 0.85–1.86) between patients selected by NCCT/CTA vs. CTP or MRI for EVT in the late window of AIS-LVO. However, patients selected by NCCT/CTA vs. CTP or MRI for EVT were associated with a higher risk of mortality (RR 1.21, 1.06–1.39).For AIS-LVO in the late window, patients selected by NCCT/CTA compared with those selected by CTP or MRI for EVT might have a comparable rate of functional independence and sICH. Baseline NCCT/CTA may triage AIS-LVO in the late window.Methods: Optimal imaging modalities to select patients for endovascular thrombectomy (EVT) in the late window of acute ischemic stroke due to large vessel occlusions (AIS-LVO) are not known. We conducted a systematic review comparing outcomes of patients selected by non-contrast computed tomography (NCCT)/CT angiography (CTA) vs. those selected by CT perfusion (CTP) or magnetic resonance imaging (MRI) for EVT in these patients.We searched PUBMED, EMBASE, and the Cochrane Library from January 1, 2000, to July 15, 2023, to identify studies comparing outcomes of patients selected for EVT by NCCT/CTA vs. CTP or MRI in the late time window for AIS-LVO. Primary outcome was independence (mRS 0–2) at 90 days or discharge. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. We pooled data across studies based on an inverse variance method.Six cohort studies with 4208 patients were included. Pooled results showed no significant difference in the rate of independence at 90 days or discharge (RR 0.96, 95% CI 0.88–1.03) and sICH (RR 1.26, 0.85–1.86) between patients selected by NCCT/CTA vs. CTP or MRI for EVT in the late window of AIS-LVO. However, patients selected by NCCT/CTA vs. CTP or MRI for EVT were associated with a higher risk of mortality (RR 1.21, 1.06–1.39).For AIS-LVO in the late window, patients selected by NCCT/CTA compared with those selected by CTP or MRI for EVT might have a comparable rate of functional independence and sICH. Baseline NCCT/CTA may triage AIS-LVO in the late window.Results: Optimal imaging modalities to select patients for endovascular thrombectomy (EVT) in the late window of acute ischemic stroke due to large vessel occlusions (AIS-LVO) are not known. We conducted a systematic review comparing outcomes of patients selected by non-contrast computed tomography (NCCT)/CT angiography (CTA) vs. those selected by CT perfusion (CTP) or magnetic resonance imaging (MRI) for EVT in these patients.We searched PUBMED, EMBASE, and the Cochrane Library from January 1, 2000, to July 15, 2023, to identify studies comparing outcomes of patients selected for EVT by NCCT/CTA vs. CTP or MRI in the late time window for AIS-LVO. Primary outcome was independence (mRS 0–2) at 90 days or discharge. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. We pooled data across studies based on an inverse variance method.Six cohort studies with 4208 patients were included. Pooled results showed no significant difference in the rate of independence at 90 days or discharge (RR 0.96, 95% CI 0.88–1.03) and sICH (RR 1.26, 0.85–1.86) between patients selected by NCCT/CTA vs. CTP or MRI for EVT in the late window of AIS-LVO. However, patients selected by NCCT/CTA vs. CTP or MRI for EVT were associated with a higher risk of mortality (RR 1.21, 1.06–1.39).For AIS-LVO in the late window, patients selected by NCCT/CTA compared with those selected by CTP or MRI for EVT might have a comparable rate of functional independence and sICH. Baseline NCCT/CTA may triage AIS-LVO in the late window.Conclusion: Optimal imaging modalities to select patients for endovascular thrombectomy (EVT) in the late window of acute ischemic stroke due to large vessel occlusions (AIS-LVO) are not known. We conducted a systematic review comparing outcomes of patients selected by non-contrast computed tomography (NCCT)/CT angiography (CTA) vs. those selected by CT perfusion (CTP) or magnetic resonance imaging (MRI) for EVT in these patients.We searched PUBMED, EMBASE, and the Cochrane Library from January 1, 2000, to July 15, 2023, to identify studies comparing outcomes of patients selected for EVT by NCCT/CTA vs. CTP or MRI in the late time window for AIS-LVO. Primary outcome was independence (mRS 0–2) at 90 days or discharge. Secondary outcomes were symptomatic intracranial hemorrhage (sICH) and mortality. We pooled data across studies based on an inverse variance method.Six cohort studies with 4208 patients were included. Pooled results showed no significant difference in the rate of independence at 90 days or discharge (RR 0.96, 95% CI 0.88–1.03) and sICH (RR 1.26, 0.85–1.86) between patients selected by NCCT/CTA vs. CTP or MRI for EVT in the late window of AIS-LVO. However, patients selected by NCCT/CTA vs. CTP or MRI for EVT were associated with a higher risk of mortality (RR 1.21, 1.06–1.39).For AIS-LVO in the late window, patients selected by NCCT/CTA compared with those selected by CTP or MRI for EVT might have a comparable rate of functional independence and sICH. Baseline NCCT/CTA may triage AIS-LVO in the late window. [ABSTRACT FROM AUTHOR]

BACKGROUND Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P=0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.) [ABSTRACT FROM AUTHOR]

Background and Purpose: It is unknown whether intracranial atherosclerotic disease (ICAD), in addition to causing stenosis, also associates with abnormal arterial enlargement, a condition known as intracranial dolichoectasia (IDE). Across symptomatic ICAD patients, we aim to determine IDE prevalence and IDE impact on cerebral hemodynamics and recurrent cerebral ischemia. Methods: We analyzed 98 participants (mean age 63.8 ± 11.9 years, 56.1% men) of the prospective observational study MYRIAD. Participants were enrolled within 21 days of an ischemic stroke or transient ischemic attack caused by moderate‐to‐severe ICAD. Semi‐automatic vessel segmentation was used to determine diameters, length, and tortuosity‐index of proximal intracranial arteries. Either ectasia (increased diameter) or dolichosis (increased length or TI) defined IDE. We assessed IDE association with new infarcts during 12‐month follow‐up, and IDE correlation with cerebral hemodynamics determined by quantitative MR‐angiography (QMRA), MR‐perfusion weighted‐imaging, and transcranial Doppler breath‐holding index. Results: IDE was present in 35.7% of patients and 10.2% of symptomatic arteries. Basilar stenosis was associated with higher IDE prevalence (27.8% vs. 8.8%, p = 0.04), whereas other symptomatic arteries showed no association with IDE. Symptomatic arteries with IDE had lower hypoperfusion prevalence on MR‐PWI (11.1% vs. 28.4%, p = 0.03). Increased diameter (r = 0.33, p<0.01) and tortuosity‐index (r = 0.29, p = 0.01) showed positive correlation with QMRA flow rate. IDE was not associated with new infarcts during follow‐up. Conclusions: IDE was common among symptomatic ICAD patients. IDE was not associated with stroke recurrence. Instead, increased diameter and tortuosity correlated with improved blood flow across the stenotic artery, suggesting that IDE may originate as an adaptive mechanism in ICAD. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association between plaque enhancement and stroke recurrence in subjects with intracranial atherosclerosis. Methods: Ischemic stroke patients with symptomatic intracranial atherosclerosis were prospectively included and followed in a comprehensive stroke center. Pre- and post-contrast vessel wall images were used to evaluate plaque enhancement. Other established suggestive imaging markers were also acquired simultaneously. Univariate- and multivariate-adjusted Cox proportional hazard regression models were used to determine the association between plaque enhancement and stroke recurrence. Finally, receiver operating characteristic (ROC) curves were used to demonstrate the predictive value of different imaging markers. Results: Of the 60 subjects included, 12 (20.0%) patients presented with ipsilateral stroke recurrence during the median 12-month follow-up. Cox proportional hazard regression models indicated that plaque enhancement was an independent risk factor associated with stroke recurrence after adjusted covariates, with a hazard ratio (HR) of 14.24 and 95% confidence interval (95% CI) (1.21, 168.11), p = 0.04. In addition, border zone infarction was also statistically significant in predicting stroke recurrence in multi-variable regression (HR = 3.80; 95% CI = 1.04, 13.80; p = 0.04). Collateral status was in marginal significance (HR = 0.25; 95% CI = 0.06, 1.08; p = 0.06). ROC analysis indicated that the area under the curve and 95% CI to identify stroke recurrence are 0.67 (0.51, 0.82) for plaque enhancement and 0.71 (0.54, 0.88) for infarction pattern and collateral status and may increase to 0.82 (0.70, 0.93) by combining the three markers above. Conclusion: Plaque enhancement is independently associated with stroke recurrence in subjects with intracranial atherosclerosis and has added value to hemodynamic indicators in predicting stroke recurrence. [ABSTRACT FROM AUTHOR]

ABSTRACT The recent culmination of imaging-endowed endovascular stroke trials has decisively proven the utility of clinically relevant neuroimaging in improving the outcome of patients with potentially debilitating neurological disorders. These large multicenter trials conducted across several continents notably utilized a variety of multimodal CT/MRI modalities to rapidly identify a favorable collateral profile that presages clinically beneficial revascularization. The modern clinical neuroimager may accelerate complex decision-making through the rational use of a variety of imaging modalities and an active feedback loop of imaging at the bedside. The modern clinical neuroimager is often the initial care provider for a wide range or type of stroke patients from hemorrhage to ischemia, armed with the incredibly important aspects of clinical history and examination findings and best poised to utilize imaging to guide therapy from acute stroke to recovery and prevention. The next generation in stroke should not exclusively focus on whether to order a CT or MRI counting minutes at the bedside, but actively and efficiently integrate the vast wealth of information available when imaging is used in the proper clinical context. The novel endovascular era in stroke provides an ideal venue for the synergistic goals of translating research advances, improving patient outcomes and ongoing education as a modern neuroimager. [ABSTRACT FROM AUTHOR]

Background: Magnesium (Mg) is a neuroprotectant in preclinical models. Lower serum Mg levels have been associated with symptomatic hemorrhagic transformation (HT) in patients with ischemic stroke. Early treatment of acute ischemic stroke with Mg may reduce rates of symptomatic HT. Methods: In this post hoc study of the Field Administration of Stroke Therapy Magnesium (FAST-MAG) trial, 1,245 participants with a diagnosis of cerebral ischemia received 20 g of Mg or placebo initiated in the prehospital setting. Posttreatment serum Mg level was measured for 809 participants. Cases of clinical deterioration, defined as worsening by ≥4 points on the National Institute of Health Stroke Scale (NIHSS), were imaged and evaluated for etiology. Symptomatic HT was defined as deterioration with imaging showing new hemorrhage. Results: Clinical deterioration occurred in 187 and symptomatic HT in 46 of 1,245 cases of cerebral ischemia. Rates of deterioration and symptomatic HT were not significantly lower in those who received Mg (15.7% vs. 14.4%, p = 0.591; 2.8% vs. 4.6%, p = 0.281). In cases where serum Mg level was obtained posttreatment, lower serum Mg level (<1.7 mg/dL) was associated with significantly higher rates of deterioration and symptomatic HT (27.5% vs. 15.5%, p = 0.0261; 11.6% vs. 3.65%, p = 0.00819). Conclusions: Treatment with Mg did not significantly reduce rates of clinical deterioration or symptomatic HT. Future analysis should address whether treatment with Mg could have influenced the subgroup with low serum Mg at baseline. [ABSTRACT FROM AUTHOR]

Background and purpose: The development of high‐resolution magnetic resonance imaging (HR‐MRI) has enabled submillimeter‐level evaluation of intracranial artery plaque and luminal thrombus. We sought to investigate the value of HR‐MRI in assessing the pathogenesis of acute intracranial artery thrombus. Methods: We examined the presence of intracranial thrombus on three‐dimensional T1‐weighted HR‐MRI in acute ischemic stroke patients with intracranial artery occlusion on magnetic resonance angiography. We defined two thrombus‐related HR‐MRI features (peri‐thrombus plaque and distal residual flow beyond the thrombus) and analyzed their association with potential embolic sources. Results: Luminal thrombus and a shrunken artery without luminal thrombus were detected in 162 (96.4%) and six (3.6%) of 168 patients with intracranial artery occlusion, respectively. Among 111 patients with culprit major artery thrombus, peri‐thrombus plaques were observed in 46.8% and distal residual flow beyond the thrombus in 64.0%. Patients with peri‐thrombus plaque had a higher prevalence of diabetes (44.2% vs. 25.4%; p = 0.037), a lower prevalence of potential sources of cardioembolism (0% vs. 16.9%; p = 0.002), and a nonsignificantly lower prevalence of potential embolic sources from extracranial arteries (9.6% vs. 20.3%; p = 0.186) than those without. Patients with distal residual flow beyond the thrombus had a lower prevalence of potential sources of cardioembolism (1.4% vs. 22.5%; p < 0.001) and smaller infarct volumes (5.0 [1.4–12.7] mL vs. 16.6 [2.4–94.6] mL; p = 0.012) than those without. Conclusions: Our study showed that HR‐MRI helps clarify the pathogenesis of acute intracranial artery thrombus. The presence of peri‐thrombus plaque and distal residual flow beyond the thrombus favor the stroke mechanism of atherosclerosis rather than cardioembolism. [ABSTRACT FROM AUTHOR]

Background: Stroke caused by acute basilar artery occlusion (BAO) is devastating with high dependency and mortality. Recent trials have demonstrated the efficacy of endovascular treatment (EVT) for acute BAO, while pretreatment collaterals may be a valuable prognostic indicator for post-EVT outcomes. Aims: To systematically review and synthesize evidence on the associations between pretreatment collateral status and outcomes after EVT in acute BAO. Methods: We retrieved relevant full-text articles published in English since 1 January 2010, reporting associations between pretreatment collateral status and outcomes after EVT for BAO, by searching MEDLINE and Embase. The primary outcome was favorable or good 90-day functional outcome (modified Rankin Scale [mRS] 0–2 or 0–3); secondary outcomes included successful recanalization, symptomatic intracranial hemorrhage, final infarct volume, and 90-day mortality. Risk ratios (RRs) with 95% confidence intervals (CIs) for good versus poor collaterals on the outcomes were synthesized using random-effects models. Subgroup and sensitivity analyses were conducted for the primary outcome. Results: Overall, 29 primary studies (2995 participants) were included in qualitative review, among which 16 studies (1447 participants) were meta-analyzed. With different imaging modalities and methods to grade the collateral status, good collaterals were found in 33–85% of patients in the individual primary studies (I2 = 95.2%, p < 0.001), with a pooled proportion of 51% (95% CI: 40–62%) across all studies. Good pretreatment collaterals were associated with a doubled rate of favorable/good 90-day functional outcome (RR = 2.03, 95% CI: 1.63–2.51, p < 0.001), a higher rate of successful recanalization (RR = 1.23, 95% CI: 1.04–1.45, p = 0.015), and reduced 90-day mortality (RR = 0.59, 95% CI: 0.43–0.81, p = 0.001) after EVT for BAO. None of the primary studies reported the associations of good collaterals with the other secondary outcomes. Subgroup analyses revealed possibly more prominent protective effect of good pretreatment collaterals over the primary outcome, in studies with longer time windows in patient eligibility criteria for EVT (p = 0.028 for between-subgroup heterogeneity). Conclusions: In patients with BAO receiving EVT, good pretreatment collateral status was associated with a higher chance of favorable 90-day functional outcome, despite the various methods in grading the collateral circulation. Efforts are needed for more standardized collateral assessment in BAO, for more reliable and generalizable investigations of its clinical implications. [ABSTRACT FROM AUTHOR]

Several landmark clinical trials of endovascular therapy for acute ischemic stroke have recently jolted the concerted multidisciplinary efforts to develop effective revascularization strategies. Further consideration of these four endovascular stroke trials published in the last year suggests a more fundamental question: are these trials of specific treatments or have the results simply reflected the importance of underlying pathophysiology? Data from IMS III, MR RESCUE, SWIFT and TREVO2 consistently demonstrate the dramatic impact of collateral perfusion in acute ischemic stroke. Such collateral, or parallel, trials of the underlying pathophysiology in stroke reveal that diagnosis or selection of optimal candidates may be paramount to the specific drug or device therapy. Future trials of endovascular therapies may harness the influential role of collaterals as critical selection criteria for intervention, with triage based on imaging rather than time alone. Treating the optimal patient may be more important than chasing an elusive magical therapy. [ABSTRACT FROM AUTHOR]

The purpose was to assess the difference of collaterals in symptomatic versus asymptomatic patients with unilateral middle cerebral artery (MCA) stenosis by comparing cerebral blood flow (CBF) at two post labeling delays (PLD) using three-dimensional pseudo-continuous arterial spin labeling (3D pCASL). Eighty-one patients (49 symptomatic and 32 asymptomatic) with unilateral MCA stenosis ≥50% who underwent pCASL with two PLDs were included. Mean CBF and CBF subtraction images between two PLDs of MCA territories were compared in symptomatic and asymptomatic groups, respectively. Compared with the asymptomatic group, patients with symptomatic MCA stenosis had significantly lower CBF in the MCA territory of stenotic side at each PLD. The CBF of stenotic territory showed greater increase than that of normal side from PLD 1.5 to 2.5 s. The CBF of asymptomatic MCA territory increased similarly with that of symptomatic MCA territory from PLD of 1.5 to 2.5 s in stenotic side, while symptomatic patients experienced significantly slower antegrade flow. On CBF subtraction images, asymptomatic patients showed larger volume of differences between PLD of 1.5 and 2.5 s compared with those of symptomatic patients (p = 0.037). The results suggest that more robust collateral perfusion on two-delay 3D pCASL is present in asymptomatic patients compared with symptomatic patients. [ABSTRACT FROM AUTHOR]