Incidence and Outcomes of Posterior Circulation Involvement in Moyamoya Disease

Stroke, Ahead of Print. BACKGROUND:Moyamoya disease (MMD) is a progressive, occlusive disease of the internal carotid arteries and their proximal branches, with the subsequent development of an abnormal vascular network that is rupture-prone. Steno-occlusive changes in the posterior cerebral arteries (PCAs) may contribute to worsened outcomes in patients with MMD; however, there is little information on the incidence and natural history of posterior circulation MMD (PCMMD). We describe clinical PCMMD characteristics in a large cohort of patients with MMD.METHODS:We retrospectively reviewed patients with MMD treated between 1991 and 2019 at a large academic medical center. Demographics, perioperative outcomes, and radiological phenotypes were recorded for 770 patients. PCA disease was graded as either 0 (no disease), 1 (mild), 2 (moderate), or 3 (severe or occluded) based on cerebral angiography. Patients with angiographically confirmed MMD diagnosis with at least 6 months follow-up and completion of revascularization surgery were included; patients with intracranial atherosclerosis, intracranial dissection, vasculitis, and undefined inflammatory processes were excluded. The presence of stenosis/occlusion was graded radiographically to assess for disease progression and the prevalence of risk factors related to reduced progression-free survival.RESULTS:In all, 686 patients met the inclusion criteria, with PCA disease identified in 282 (41.1%) patients. Of those 282 patients with PCMMD, disease severity ranged from 99 (35.1%) with mild, 72 (25.5%) with moderate, and 111 (39.4%) with severe. The total number of postoperative complications was significantly associated with PCMMD severity (P=0.0067). Additionally, PCMMD severity correlated with worse postoperative modified Rankin Scale scores (P

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Aprile 2024

Inflammatory Type Focal Cerebral Arteriopathy of the Posterior Circulation in Children: A Comparative Cohort Study

Stroke, Ahead of Print. BACKGROUND:Inflammatory type focal cerebral arteriopathy (FCA-i) in the anterior circulation (AC) is well characterized, and the focal cerebral arteriopathy severity score (FCASS) reflects the severity of the disease. We identified cases of FCA-i in the posterior circulation (PC) and adapted the FCASS to describe these cases.METHODS:In this comparative cohort study, patients from the Swiss NeuroPaediatric Stroke Registry with ischemic stroke due to FCA-i between January 2000 and December 2018 were analyzed. A comparison between PC and AC cases regarding pediatric National Institutes of Health Stroke Scale score and pediatric stroke outcome measure and FCASS was performed. We estimated infarct size by the modified pediatric Alberta Stroke Program Early Computed Tomography Score in children with AC stroke and the adapted Bernese posterior diffusion–weighted imaging score in the PC.RESULTS:Thirty-five children with a median age of 6.3 (interquartile range, 2.7–8.2 [95% CI, 0.9–15.6]; 20 male; 57.1%) years with FCA-i were identified. The total incidence rate was 0.15/100 000/year (95% CI, 0.11–0.21). Six had PC-FCA-i. Time to final FCASS was longer in the PC compared with AC; the evolution of FCASS did not differ. Initial pediatric National Institutes of Health Stroke Scale score was higher in children with FCA-i in the PC with a median of 10.0 (interquartile range, 5.75–21.0) compared with 4.5 (interquartile range, 2.0–8.0) in those with AC-FCA-i. Different from the anterior cases, PC infarct volume did not correlate with higher discharge, maximum, or final FCASS scores (Pearson correlation coefficient [r], 0.25, 0.35, and 0.54).CONCLUSIONS:FCA-i also affects the PC. These cases should be included in future investigations into FCA-i. Although it did not correlate with clinical outcomes in our cohort, the modified FCASS may well serve as a marker for the evolution of the arteriopathy in posterior FCA-i.

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Marzo 2024

Abstract TP130: Prevalence of Fast Progressors of Infarct Growth in Anterior Circulation Large Vessel Occlusions <6 Hours From Onset

Stroke, Volume 55, Issue Suppl_1, Page ATP130-ATP130, February 1, 2024. Background/Purpose:Fast progressors (FP) of infarct growth in anterior circulation large vessel occlusions (LVO) may be prevalent in the =70mL of overall hypoperfusion present; and as “FP100” with IGR >16.7mL/h (which would result in an ICV >100mL by 6h)andhad >=100mL of overall hypoperfusion present.Results:108 patients were included with median (IQR) age of 75.5 (67-85), NIHSS of 20 (12-24), onset time of 2h (1.5-4), median ICV of 11mL (0-40), hypoperfusion volume of 122mL (70-164), and mismatch volume of 86.5mL (58-130). The sites of LVO were ICA 12 (11.1%), M1 73 (67.6%), and both 23 (21.3%). Median IGR for the cohort was 3.8mL/h (0-16.4). 31 FP70 were found (28.7%, 95% CI: 19.5-40.7%) with median IGR of 31.3mL/h (16.8-42). 14 of these (45.2%, 95% CI: 24.7-75.8%) already had ICV >70mL upon arrival, with median of 100mL (86-156) and 8 of 14 also showed mismatch ratio 100mL upon arrival, with median of 138mL (101-172) and 5 of 8 also showed mismatch ratio

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Febbraio 2024

Abstract WP190: Comparison of Collateral Score to ASPECTS to Exclude “Very Large” Infarct Core Volumes in Anterior Circulation Large Vessel Occlusion Strokes at 0-24 Hours

Stroke, Volume 55, Issue Suppl_1, Page AWP190-AWP190, February 1, 2024. Purpose:ASPECTS100mL) for reperfusion using endovascular thrombectomy (EVT). While specific, ASPECTS100mL while maintaining similar specificity to ASPECTS.Methods:Retrospective analysis included consecutive stroke patients arriving within 24 hours of onset, with intracranial ICA and/or M1 occlusion on CTA, and had concurrent CT perfusion. RAPID AI software estimated ICV using the rCBF0 but =50 but 100mL. Sensitivity and specificity of that CS threshold vs ASPECTS100mL (9.8%) with median of 136mL (105-172). Using ASPECTS

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Febbraio 2024

Abstract TP119: Predicting Posterior Circulation Stroke During Emergency Triage: Dizzy-7 Project

Stroke, Volume 55, Issue Suppl_1, Page ATP119-ATP119, February 1, 2024. Introduction:“Stroke code” activation is a uniform process to summon healthcare stakeholders to orchestrate the rapid sequential steps for urgent management in patients with possible stroke. Acute dizziness, a common emergency department (ED) presentation, frequently leads to stroke code activation; however, cancellation rates remain high and process improvement strategies are warranted.Methods:We analyzed stroke identification accuracy, cancellation rates, and clinical characteristics in patients presenting with an acute vestibular syndrome to inform process improvement strategies for stroke code activation. We developed an ED triage diagnostic algorithm termed, “Dizzy-7”, based on evidence incorporating key history and physical examination elements derived in patients with acute posterior circulation ischemia. Subsequent analyses were performed on algorithmic utilization and its ability to predict stroke.Results:1599 patients presented with acute dizziness over a 4-month period (2022-2023). Stroke code activation occurred in nearly one in four (366/1599) these presentations. 20% (319/1599) were ultimately diagnosed with stroke and of these, 49% (319/366) were identified following stroke code activation. The Dizzy-7 algorithm was used infrequently (4%) among all acute dizziness presentations. Of the 65 cases that incorporated the algorithm, 16 resultant stroke code activations occurred with 1 confirmed diagnosis (6%). We analyzed stroke alert cancellation and found an increased frequency in cancellation for those without use of the protocol at 22% (77/350) compared to those who did use it at 6% (1/16).Discussion:Accurate and reliable identification of acute ischemic stroke among patients presenting with acute dizziness remains complex. Implementation of a triage diagnostic algorithm based on contemporary evidence was infrequently implemented. Process improvement efforts targeted at greater algorithmic use, interprofessional collaboration, and education may improve stroke code utilization efficiency. Although based on limited sample size, a trend towards reduced stroke code cancellation rates were seen throughout the pilot Dizzy-7 algorithm use.

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Febbraio 2024

Abstract TP246: Circadian Variability of the Clot Burden Score in Acute Anterior Circulation Ischemic Stroke

Stroke, Volume 55, Issue Suppl_1, Page ATP246-ATP246, February 1, 2024. Background/Purpose:Fibrinolytic activity in blood plasma displays a circadian rhythm with a drop in the morning hours that may predispose to acute thrombotic events. The Clot Burden Score (CBS) is a semiquantitative measure on CT angiography (CTA) of thrombus extent in proximal anterior circulation strokes that has been correlated with functional outcome. Higher clot burden has also been shown to have lower recanalization rates with intravenous thrombolytics. We aimed to investigate whether CBS is a parameter that displays circadian variability.Methods:We performed a retrospective analysis on consecutive stroke patients presenting 0.107.Conclusion:CBS as a measure of thrombus extent in proximal anterior circulation strokes on CTA appears to show circadian variability, with lower scores (higher clot burden) during MORNING onset (6:00-11:59) than the EVENING (18:00-23:59). This may have implications for future studies of chronotherapeutic protocols.

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Febbraio 2024

Abstract WP248: Developing and Validating Post-Treatment HERMES Score to Predict Outcome From Anterior Circulation Large Vessel Occlusion Stroke: A Meta-Analysis of Individual Data From 7 Randomized Clinical Trials

Stroke, Volume 55, Issue Suppl_1, Page AWP248-AWP248, February 1, 2024. Introduction:Clinicians need simple and highly predictive prognostic scores to assist practical decision-making and family discussion. We aimed to develop and validate a simple prediction score applied at 24 hours to assist prognostication in patients with anterior circulation ischemic stroke due to large vessel occlusion.Methods:Using the HERMES collaboration dataset (n = 1764), patients in the endovascular therapy (EVT) arm were divided randomly into a derivation cohort (n = 430) and a validation cohort (n = 441). From a set of candidate predictors, forward selection using c-statistics was employed to select a model which was both parsimonious and highly predictive for modified Rankin Scale (mRS) ≤2 at 90 days. The score was validated in both the EVT validation cohort and in the control arm (n = 893) for mRS ≤2 and ≤3.Results:In the derivation cohort, two significant predictors of mRS ≤2 (National Institutes of Health Stroke Scale [NIHSS] score at 24 h and age [β-coefficient 0.34 and 0.06]) were selected. Incorporating other variables did not much improve model performance. Among models with different weights, we derived the HERMES score: age (years)/10 + NIHSS score at 24 h, based on model performance and simplicity. The HERMES score was highly predictive for mRS ≤2 in the derivation cohort, validation cohort-EVT, and control arm (c-statistics 0.907, 0.914, and 0.909, respectively). Evaluation of the score against mRS ≤3 as an alternative outcome yielded similar results (c-statistics 0.911, 0.903, and 0.885). Among 435 subjects (24.7%) with HERMES score ≥25, the observed probability was 3.1-3.4% for mRS ≤2 and 9.4-16.7% for mRS ≤3 in the derivation cohort, validation cohort-EVT, and control arm (Figure).Conclusions:The HERMES score is a simple validated score to predict outcomes in patients with anterior circulation large vessel occlusion ischemic stroke regardless of intervention. HERMES score should be helpful in prognostic discussion with families on day two.

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Febbraio 2024

Abstract TP53: Above Par on the Back Nine: Improving Triage of Posterior Circulation Stroke

Stroke, Volume 55, Issue Suppl_1, Page ATP53-ATP53, February 1, 2024. Background and Purpose:Notoriously difficult to recognize, posterior circulation strokes (PCS) can be some of the most devastating. It is incumbent on the triage nurse to recognize these signs and symptoms. This project was developed to educate frontline ED staff on early identification of posterior strokes, decrease time to recognition, and improve outcomes.Methods:The community Primary Stroke Center (PSC) identified the need to improve recognition of PCS after a series of treatment-eligible patients were missed. A team was created including the directors of the PSC and associated Comprehensive Stroke Center (CSC), emergency room physicians, and nurses. A triage algorithm was created to capture as many strokes as possible without a glut of false positives. This included focal and non-focal signs of stroke. ANY sign of stroke should initiate the code stroke (CS) process provided that the presentation was within 24 hours of last known well, the presentation was sudden, and the symptoms were disabling to the patient. Once approved, the algorithm and education were provided to all patient-facing ED staff. Updates were added to huddle notes and a copy of the algorithm was made available at all triage areas. Data was collected retroactively for a total of 16 months, 8 months prior to the intervention and 8 months after.Results:- For all PCS the median time from arrival to initiation of CS improved from 9 minutes to 1 minute- For all PCS the median time from arrival to confirmation of stroke improved from 597 minutes to 249 minutes- Prior to intervention, only 60% of CS-eligible patients had a CS initiated, compared to 92% after- Ninety-day Rankin was from 0-2 in 86% of PCS patients prior to intervention compared to 100% afterConclusions:A clear triage process can maximize identification of PCS, increase capture of treatment-eligible patients, and decrease disability. A PSC with tele-stroke coverage and ongoing education improved identification of posterior circulation strokes and outcomes. Key takeaways for success include clear and concise code stroke algorithm, support from providers, and ongoing educational interventions. While this data is preliminary, we will continue to track and trend. Next steps should include education directed to EMS personnel in the field.

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Febbraio 2024

Abstract 153: First Pass Effect in Mechanical Thrombectomy for Anterior Circulation Acute Ischemic Stroke is Modified by Procedure Time: Proposal of a New Measure for Thrombectomy Procedures

Stroke, Volume 55, Issue Suppl_1, Page A153-A153, February 1, 2024. Objective:To determine whether first pass effect (FPE) after mechanical thrombectomy (MT) for anterior circulation large vessel occlusion acute ischemic stroke (LVO-AIS) is modified by procedural time (PT).Methods:The Stroke Thrombectomy and Aneurysm Registry (STAR), a multi-center international dataset, was retrospectively analyzed for anterior circulation LVO-AIS treated by MT who achieved excellent reperfusion (TICI 2c/3). The primary outcome was good functional outcome as defined by a 90-day modified Rankin Scale (mRS) 0-2. The primary study exposure was first pass success (FPS, 1 pass vs ≥2 passes) and the secondary exposure was PT. Logistic regression models were fit-adjusted and marginal effects used to assess the interaction of PT (≤30 vs >30 minutes) and FPS, adjusting for potential confounders including time from last known well to start of MT.Results:A total of 1,310 patients had excellent reperfusion. These patients were divided into two cohorts based on PT: ≤30 minutes (777 patients, 59.3%) and > 30 minutes (533 patients, 40.7%). Good functional outcome was observed in 658 patients (50.2%). The interaction term between FPS and PT was significant (p=0.018). Individuals with FPS in ≤30 minutes had 11.5% higher adjusted predicted probability of good outcome compared with those who required ≥2 passes (58.2% vs. 46.7%, p=0.001). However, there was no significant difference in the adjusted predicted probability of good outcome based on FPS in individuals with PT >30 minutes (p=0.763). This relationship appeared identical in models with PT treated as a continuous variable.Conclusion:In a large, real-world, multi-national dataset, we find that FPE is importantly modified by PT. The added clinical benefit of FPE is lost in longer procedures ( >30 minutes). These data argue for a new metric for MT procedures, namely, FPE30, that better represents the ideal of fast, complete reperfusion with a single pass of a thrombectomy device.

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Febbraio 2024

Abstract TP252: Forward Head Posturing as a Significant Risk Factor for Posterior Circulation Infarcts

Stroke, Volume 55, Issue Suppl_1, Page ATP252-ATP252, February 1, 2024. Objective:Forward head posturing (FHP) has been associated with chronic anatomic vertebral artery disturbances possibly leading to posterior circulation ischemia. The data supporting FHP as a true risk factor of posterior circulation stroke has not been well established. We aim to study if patients with severe cervical myalgias and FHP have an increased risk of posterior circulation stroke.Methods:We identified all adult patients with posterior circulation stroke and diagnosis of cervical myalgia at Loyola University Medical Center from January 2018 to January 2023. Information on demographics and comorbidities were also collected. We then identified matched pair case-controls (based on age and gender) with non-stroke cervical myalgia patients in the same 5-year period. We compared the relevant comorbidities, C2 tilt angle, and C2-C7 tilt angle of patients to their matched controls to for statistical difference.Results:76 patients (38 cases and 38 controls) with an average age of 64 years, including 38 (50%) females met our inclusion criteria. The average C2 tilt of cases was 22.9 degrees compared to 17.7 degrees in controls, and the average C2-C7 tilt of cases was 18.9 degrees in cases compared 10.5 degrees in controls. There were no significant differences between relevant comorbidities (including hypertension, hyperlipidemia, diabetes, atrial fibrillation, hyper-coagulopathy, or body mass index) of cases and controls. There was a significant difference of 5.2 degrees higher C2 tilt and 8.1 degrees higher C2-C7 tilt in cases compared to controls respectively (p-value = 0.03).Conclusion:In this single-center retrospective analysis, we found that after controlling for age, gender, and comorbidities, patients with posterior circulation stroke were more likely to have significantly higher C2 and C2-C7 cervical tilt (worse FHP based on radiographic standards) compared to their matched control counterparts.

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Febbraio 2024

Abstract TP132: Optimal CT Perfusion Post-Processing Method in Posterior Circulation Stroke

Stroke, Volume 55, Issue Suppl_1, Page ATP132-ATP132, February 1, 2024. Objective:CT-perfusion (CTP) has revolutionised stroke care by improving diagnostic accuracy and expanding eligibility to acute therapies. Software packages utilise various mathematical techniques to transform raw perfusion data into measures of infarct core and ischaemic penumbra. These techniques have been derived from studies of anterior-circulation stroke and not yet validated in posterior circulation stroke (PCS). We examined the optimal CTP thresholds for acute PCS.Methods:Data were analysed from 331-patients diagnosed with a PCS enrolled in the International-stroke-perfusion-registry (INSPIRE). Twenty-seven-patients with baseline multimodal-CT with occlusion of a large posterior-circulation (PC) artery and follow up diffusion-weighted-MRI at 24-48 hours were included. CTP parametric maps were generated using five different post-processing methods. Receiver-operating-curve analysis was used to determine the optimal perfusion parameter and thresholds.Results:Partial deconvolution was the optimal post-processing method for characterisation of ischaemic penumbra and infarct core. Mean transit time (MTT) at a threshold of >165% and >195% most accurately defined ischaemic core (AUC=0.73) and penumbra (AUC=0.78) respectively. Post-processing technique influenced accuracy of core (AUC range=0.54-0.73) and penumbra (AUC range=0.72-0.79) estimates. MTT was consistently the most accurate parameter at distinguishing core and penumbra across all post-processing methods.Conclusion:CTP has significant diagnostic utility in PCS. Accuracy of CTP varies considerably by post-processing method. The underlying post-processing technique employed by individual software packages should be considered when interpreting the accuracy of ischemic core and penumbra estimates.

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Febbraio 2024

Abstract TP175: Older Age is Associated With Smaller Ischemic Core Volume and Slower Infarct Progression Despite High Clinical Severity in Anterior Circulation Large Vessel Occlusion Stroke

Stroke, Volume 55, Issue Suppl_1, Page ATP175-ATP175, February 1, 2024. Background:Older patients with acute stroke due to anterior circulation large vessel occlusion (ACLVO) experience worse clinical outcomes. Fast progressors typically present early with high stroke severity and larger ischemic core volumes. However, the relationship between aging and early infarct growth rate is unknown. We examined the association between older age, baseline ischemic core volumes and fast or slow infarct growth during ACLVO.Methods:Retrospective study of patients with acute ICA or MCA occlusion across two academic centers in 2014-2019. Patients were included if they had baseline CTP or MRI within 24 hours after estimated stroke onset. Infarct growth rate (IGR) was calculated as ischemic core volume (ml) / stroke onset to imaging time (h). Fast or Slow progressor status was defined by IGR ≥ or < 10 ml/h. Univariate comparisons were made across age tertiles. Multivariable linear and logistic regression analysis examined the association of age tertile with ischemic core volume and slow progressor status adjusting for sex, vascular co-morbidities and NIHSS.Results:We included 312 patients (57% female; age tertiles [T1-T3]: 33—66, 67—81, and 82—102). Older age was associated with decreasing ischemic core volume (median [range] ml: T1, 29 [0-253]; T2, 12 [0-406]; T3, 6 [0-244]; p

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Febbraio 2024

Abstract TMP96: Clear Thrombectomy Score: An Index to Estimate Probability of Good Functional Outcome Following Endovascular Treatment in the Late Window for Anterior Circulation Occlusion

Stroke, Volume 55, Issue Suppl_1, Page ATMP96-ATMP96, February 1, 2024. Background:Endovascular thrombectomy (EVT) has established efficacy across a wide range of patient age, radiological findings, and clinical features. However, EVT may be less effective in extreme scenarios (e.g., large established infarction in later treatment windows), where there are currently limited data.Methods:A heterogeneous, multinational observational cohort (CLEAR registry) of consecutive adult patients ≥18 years old who underwent EVT for acute occlusion (2014-2022) of the internal carotid or proximal middle cerebral (M1 or M2) arteries was queried (n=64 sites). A high-fidelity model for predicting good functional outcome at 90 days (return to pre-stroke modified Rankin Scale [mRS] or mRS 0-2 after EVT) was developed using a binary, multivariable logit model with adaptive double lasso adjustment, which was validated using 5-fold cross validation and 1000 bootstrap sampling for confidence intervals.Results:At the time of the analysis, we evaluated 2953 patients from the registry treated with EVT, of which 1855 (63%) had complete covariate data for inclusion. The median National Institutes of Health Stroke Scale (NIHSS) score was 15 (IQR 9-20), with 14.0% having a pre-stroke mRS >2, 8.3% having a NIHSS

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Febbraio 2024