Alberta Stroke Program Early CT Scoring of CT perfusion in early stroke visualization and assessment

A Retrospective Analysis of the Effects of Concomitant Use of Intra-Aortic Balloon Pump (IABP) and Veno-Arterial Extracorporeal Membrane Oxygenation (va-ECMO) Therapy on Procedural Brain Infarction

Background/Objectives: Brain ischemia is a frequent complication in patients undergoing veno-arterial extracorporeal membrane oxygenation (va-ECMO) therapy due to hypoperfusion, low oxygenation, and thromboembolism. While concomitant intra-aortic balloon pump (IABP) therapy may improve the perfusion of the supra-aortic branches, it may also favor thromboembolism. This retrospective study aimed to evaluate the effects of combined va-ECMO and IABP therapy on procedural brain infarction compared to va-ECMO therapy alone, with a specific focus on analyzing the types of infarctions. Methods: Cranial computed tomography (CCT) scans of consecutive patients receiving va-ECMO therapy were analyzed retrospectively. Subgroups were formed for patients with combined therapy (ECMO and IABP) and va-ECMO therapy only. The types of infarctions and the potential impacts of va-ECMO vs. combined therapy with IABP on stroke were investigated. Results: Overall, 146 patients (36 female, 110 male, mean age 61 ± 13.3 years) were included, with 69 undergoing combined therapy and 77 patients receiving va-ECMO therapy alone. In total, 14 stroke events occurred in 11 patients in the ECMO-only group and there were 12 events in 12 patients in the ECMO + IABP-group, showing no significant difference (p = 0.61). The majority of infarctions were of thromboembolic (n = 23; 88%) origin, with 14 stroke-events in 12 patients in the ECMO + IABP-group and 9 stroke events in the ECMO-only group. The survival rate within 30 days of treatment was 29% in the ECMO-only group and 32% in the ECMO + IABP group. Conclusions: The results of this retrospective study show that concomitant IABP therapy appears to be neither protective nor more hazardous in relation to ECMO-related stroke. Thus, the indication for additional IABP therapy should be assessed independently from the procedural risk of brain ischemia. Thromboembolic infarctions seem to represent the most common type of infarction in ECMO, especially within the first 48 h of treatment.

Stenting for Symptomatic Severe Intracranial Arterial Stenosis with Downstream Perfusion Deficit in Anterior Circulation: A Retrospective Propensity-Matched Study

PURPOSE

The purpose of this study is to investigate whether patients with symptomatic severe intracranial atherosclerotic stenosis (ICAS) and downstream perfusion deficit could benefit from adding percutaneous transluminal angioplasty and stenting (PTAS) to medical therapy.

MATERIALS AND METHODS

We retrospectively reviewed patients with symptomatic severe ICAS and an Alberta Stroke Program Early CT score of < 6 on mean transit time map who received either medical plus PTAS therapy (PTAS group) or medical therapy alone (medical group) between January 2016 and December 2019 at a single center. After 1:1 propensity score matching, we analyzed the primary outcome-cumulative event rate (defined as ischemic stroke in the qualifying artery)-along with four secondary outcomes (any intracranial hemorrhage within 30 days; disabling stroke or death; any stroke, transient ischemic attack, or cardiovascular events; and death by the end of follow-up).

RESULTS

A total of 145 patients (79 in the PTAS group, 66 in the medical group) were included. After PSM, during a median follow-up of 43 months, the cumulative event rate was significantly lower in the PTAS group (11.6% [5/43]) than in the medical group (34.9%[15/43]; hazard ratio:0.35; 95%CI:0.15-0.85; P = 0.034). No significant difference was found for the primary outcome of ischemic stroke within 30 days or 1, 2, and 3 years, or for other secondary outcomes.

CONCLUSIONS

PTAS combined with medical therapy was associated with a lower probability of ischemic stroke over three years of follow-up than medical therapy alone. These findings should be interpreted with caution due to the study's retrospective design and single-center setting.

Deep learning-based automatic ASPECTS calculation can improve diagnosis efficiency in patients with acute ischemic stroke: a multicenter study

OBJECTIVES

The Alberta Stroke Program Early CT Score (ASPECTS), a systematic method for assessing ischemic changes in acute ischemic stroke using non-contrast computed tomography (NCCT), is often interpreted relying on expert experience and can vary between readers. This study aimed to develop a clinically applicable automatic ASPECTS system employing deep learning (DL).

METHODS

This study enrolled 1987 NCCT scans that were retrospectively collected from four centers between January 2017 and October 2021. A DL-based system for automated ASPECTS assessment was trained on a development cohort (N = 1767) and validated on an independent test cohort (N = 220). The consensus of experienced physicians was regarded as a reference standard. The validity and reliability of the proposed system were assessed against physicians' readings. A real-world prospective application study with 13,399 patients was used for system validation in clinical contexts.

RESULTS

The DL-based system achieved an area under the receiver operating characteristic curve (AUC) of 84.97% and an intraclass correlation coefficient (ICC) of 0.84 for overall-level analysis on the test cohort. The system's diagnostic sensitivity was 94.61% for patients with dichotomized ASPECTS at a threshold of ≥ 6, with substantial agreement (ICC = 0.65) with expert ratings. Combining the system with physicians improved AUC from 67.43 to 89.76%, reducing diagnosis time from 130.6 ± 66.3 s to 33.3 ± 8.3 s (p < 0.001). During the application in clinical contexts, 94.0% (12,591) of scans successfully processed by the system were utilized by clinicians, and 96% of physicians acknowledged significant improvement in work efficiency.

CONCLUSION

The proposed DL-based system could accurately and rapidly determine ASPECTS, which might facilitate clinical workflow for early intervention.

CLINICAL RELEVANCE STATEMENT

The deep learning-based automated ASPECTS evaluation system can accurately and rapidly determine ASPECTS for early intervention in clinical workflows, reducing processing time for physicians by 74.8%, but still requires validation by physicians when in clinical applications.

KEY POINTS

The deep learning-based system for ASPECTS quantification has been shown to be non-inferior to expert-rated ASPECTS. This system improved the consistency of ASPECTS evaluation and reduced processing time to 33.3 seconds per scan. 94.0% of scans successfully processed by the system were utilized by clinicians during the prospective clinical application.

Association of early seizures after ischemic stroke with diffusion-weighted imaging-alberta stroke program early CT score (DWI-ASPECTS) and neutrophil-to-lymphocyte ratio

BACKGROUND

Post-stroke seizure (PSS) is a common considerable complication of acute ischemic stroke (AIS). Early risk assessment can clinical practitioners to plan effective prevention and management. We aimed to determine whether assessing Diffusion-Weighted Imaging-Alberta Stroke Program Early CT Score (DWI-ASPECTS), and neutrophil indices allows for identifying patients at risk of PSS.

METHODS

This prospective study included AIS patients with cortical involvement admitted to a single academic center between January 2020 to October 2023. For all included subjects, DWI-Brain MRI, blood neutrophils, and platelet counts were obtained and the DWI-ASPECTS score was calculated. Then, the patients were followed up for 6 months in terms of PSS occurrence. Based on the occurrence of PSS, patients were divided into two groups of PSS and non-PSS. For analysis, imaging and laboratory data were compared between two groups. Logistic regression was applied to determine the relationship between DWI-ASPECTS and neutrophil indices, with early PSS. Finally, the sensitivity and specificity of these variables for PSS were estimated.

RESULTS

A total of 309 were included in the final statistical analysis. DWI-ASPECT and neutrophil-to-lymphocyte ratio (NLR) were significantly associated with early PSS with OR of 0.74 and OR of 1.13, respectively (P < 0.05). Further analysis showed that, a combination of DWI-ASPECTS, NLR had an area under the curve (AUC) of 0.72 for predicting the occurrence of early PSS.

CONCLUSION

DWI-ASPECTS and NLR are associated with the occurrence of early PSS after cortical ischemic stroke. A combination of these predictors had higher sensitivity and specificity for PSS rather than each factor alone. These findings may be helpful for determining the risk of PSS if validated in future studies.

CT Imaging Computed Tomography/Computed Tomography Angiography/Perfusion in Acute Ischemic Stroke and Vasospasm

Computed tomography (CT), CT angiography (CTA), and CT perfusion (CTP) play crucial roles in the comprehensive evaluation and management of acute ischemic stroke, aneurysmal subarachnoid hemorrhage (SAH), and vasospasm. CTP provides functional data about cerebral blood flow, allowing radiologists, neurointerventionalists, and stroke neurologists to more accurately delineate the volume of core infarct and ischemic penumbra allowing for patient-specific treatment decisions to be made. CTA and CTP are used in tandem to evaluate for vasospasm associated with aneurysmal SAH and can help provide an insight into the physiologic impact of angiographic vasospasm, better triaging patients for medical and interventional treatment.

Region-specific interobserver agreement of the Alberta Stroke Program Early Computed Tomography Score: A meta-analysis

BACKGROUND AND PURPOSE

The Alberta Stroke Program Early CT Score (ASPECTS) is a widely used scoring system for evaluating ischemic stroke to determine therapeutic strategy. However, there is variation in the interobserver agreement of ASPECTS. This systematic review and meta-analysis aimed to investigate the interobserver agreement of total and regional ASPECTS.

METHODS

A comprehensive search was conducted in the Web of Sciences, PubMed, and Scopus databases to identify relevant studies. Inclusion criteria were studies of noncontrast CT performed within 24 hours of ischemic stroke in the middle cerebral artery territory.

RESULTS

A total of 20 studies, with 3482 patients, reporting interobserver agreement of total and regional ASPECTS were included in the meta-analysis. The interobserver agreement for total ASPECTS in studies using Kappa coefficient (κ) analysis was substantial (κ = .67, 95% confidence interval [CI]: .57-.78). In studies using intraclass correlation coefficient (ICC) analysis, agreement was excellent (ICC = .84, 95% CI: .77-.90). Interobserver agreement was higher in studies in which the observer was unblinded to clinical scenario in both groups (κ = .74, 95% CI: .59-.89, and ICC = .82, 95% CI: .79-.85). Per-region analysis showed that the caudate nucleus had the highest agreement (κ = .68, 95% CI: .60-.76, and ICC = .84, 95% CI: .74-.93), while M2 and internal capsule in Kappa studies (κ = .45, 95% CI: .34-.55 and κ = .47, 95% CI: .28-.66), and M4 and internal capsule in ICC studies (ICC = .54, 95% CI: .43-.64 and ICC = .55, 95% CI: .18-.91) had the lowest agreement.

CONCLUSION

This meta-analysis demonstrates substantial to excellent interobserver agreement for total ASPECTS, which supports using this method for stroke treatment. However, findings emphasize the need to consider interobserver agreement in specific regions of ASPECTS for treatment decisions.

A novel fully automated method for measuring ASPECTS to improve stroke diagnosis: Comparison to traditional ASPECTS

BACKGROUND AND PURPOSE

To compare the accuracy of subjective Alberta Stroke Program Early CT Score (sASPECTS) evaluation and that of an automated prototype software (aASPECTS) on nonenhanced CT (NECT) in patients with early anterior territory stroke and controls using side-to-side quantification of hypoattenuated brain areas.

METHODS

We retrospectively analyzed the NECT scans of 42 consecutive patients with ischemic stroke before reperfusion and 42 controls using first sASPECTS and subsequently aASPECTS. We assessed the differences in Alberta Stroke Program Early CT Score (ASPECTS) and calculated the sensitivity and specificity of NECT with CT perfusion, whereas cerebral blood volume (CBV) served as the reference standard for brain infarction.

RESULTS

The clot was located in the middle cerebral artery (MCA) in 47.6% of cases and the internal carotid artery (ICA) in 28.6% of cases. Ten cases presented combined ICA and MCA occlusions. The stroke was right sided in 52.4% of cases and left sided in 47.6%. Reader-based NECT analysis yielded a median sASPECTS of 10. The median CBV-based ASPECTS was 7. Compared to the area of decreased CBV, sASPECTS yielded a sensitivity of 12.5% and specificity of 86.8%. The software prototype (aASPECTS) yielded an overall sensitivity of 65.5% and a specificity of 92.2%. The interreader agreement for ASPECTS evaluation of admission NECT and follow-up CT was almost perfect (κ = .93). The interreader agreement of the CBV color map evaluation was substantial (κ = .77).

CONCLUSIONS

aASPECTS of NECT can outperform sASPECTS for stroke detection.

Artificial Intelligence in Stroke Imaging: A Comprehensive Review

The aging population challenges the health-care system with chronic diseases. Cerebrovascular diseases are important components of these chronic conditions. Stroke is the acute cessation of blood in the brain, which can lead to rapid tissue loss. Therefore, fast, accurate, and reliable automatic methods are required to facilitate stroke management. The performance of artificial intelligence (AI) methods is increasing in all domains. Vision tasks, including natural images and medical images, are particularly benefiting from the skills of AI models. The AI methods that can be applied to stroke imaging have a broad range, including classical machine learning tools such as support vector machines, random forests, logistic regression, and linear discriminant analysis, as well as deep learning models, such as convolutional neural networks, recurrent neural networks, autoencoders, and U-Net. Both tools can be applied to various aspects of stroke management, including time-to-event onset determination, stroke confirmation, large vessel occlusion detection, difusion restriction, perfusion deficit, core and penumbra identification, afected region segmentation, and functional outcome prediction. While building these AI models, maximum care should be exercised in order to reduce bias and build generalizable models. One of the most important prerequisites for building unbiased models is collecting large, diverse, and quality data that reflects the underlying population well and splitting the training and testing parts in a way that both represent a similar distribution. Explainability and trustworthiness are other important properties of machine learning models that could be widely adopted in clinical practices.

Automated advanced imaging in acute ischemic stroke. Certainties and uncertainties

The purpose of this is study was to review pearls and pitfalls of advanced imaging, such as computed tomography perfusion and diffusion-weighed imaging and perfusion-weighted imaging in the selection of acute ischemic stroke (AIS) patients suitable for endovascular treatment (EVT) in the late time window (6-24 h from symptom onset). Advanced imaging can quantify infarct core and ischemic penumbra using specific threshold values and provides optimal selection parameters, collectively called target mismatch. More precisely, target mismatch criteria consist of core volume and/or penumbra volume and mismatch ratio (the ratio between total hypoperfusion and core volumes) with precise cut-off values. The parameters of target mismatch are automatically calculated with dedicated software packages that allow a quick and standardized interpretation of advanced imaging. However, this approach has several limitations leading to a misclassification of core and penumbra volumes. In fact, automatic software platforms are affected by technical artifacts and are not interchangeable due to a remarkable vendor-dependent variability, resulting in different estimate of target mismatch parameters. In addition, advanced imaging is not completely accurate in detecting infarct core, that can be under- or overestimated. Finally, the selection of candidates for EVT remains currently suboptimal due to the high rates of futile reperfusion and overselection caused by the use of very stringent inclusion criteria. For these reasons, some investigators recently proposed to replace advanced with conventional imaging in the selection for EVT, after the demonstration that non-contrast CT ASPECTS and computed tomography angiography collateral evaluation are not inferior to advanced images in predicting outcome in AIS patients treated with EVT. However, other authors confirmed that CTP and PWI/DWI postprocessed images are superior to conventional imaging in establishing the eligibility of patients for EVT. Therefore, the routine application of automatic assessment of advanced imaging remains a matter of debate. Recent findings suggest that the combination of conventional and advanced imaging might improving our selection criteria.

Impact of anesthesia modalities on functional outcome of mechanical thrombectomy in patients with acute ischemic stroke: a subgroup analysis of DIRECT-MT trial

BACKGROUND

This subgroup analysis of Direct Intraarterial Thrombectomy in Order to Revascularize Acute Ischemic Stroke Patients with Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals Multicenter Randomized Clinical Trial (DIRECT-MT) aimed to investigate the influence of anesthesia modalities on the outcomes of endovascular treatment.

METHODS

Patients were divided into two groups by receiving general anesthesia (GA) or non-general anesthesia (non-GA). The primary outcome was assessed by the between-group difference in the distribution of the modified Rankin Scale (mRS) at 90 days, estimated using the adjusted common odds ratio (acOR) by multivariable ordinal regression. Differences in workflow efficiency, procedural complication, and safety outcomes were analyzed.

RESULTS

Totally 636 patients were enrolled (207 for GA and 429 for non-GA groups). There was no significant shift in the mRS distribution at 90 days between the two groups (acOR, 1.093). The median time from randomization to reperfusion was significantly longer in GA group (116 vs. 93 min, P < 0.0001). Patients in non-GA group were associated with a significantly lower NIHSS score at early stages (24 h, 11 vs 15; 5-7 days or discharge, 6.5 vs 10). The rate of severe manipulation-related complication did not differ significantly between GA and non-GA groups (0.97% vs 3.26%; P = 0.08). There are no differences in the rate of mortality and intracranial hemorrhage.

CONCLUSIONS

In the subgroup analysis of DIRECT-MT, we found no significant difference in the functional outcome at 90 days between general anesthesia and non-general anesthesia, despite the workflow time being significantly delayed for patients with general anesthesia. Clinical trail registration clinicaltrials.gov Identifier: NCT03469206.

Can flat-detector CT after successful endovascular treatment predict long-term outcome in patients with large vessel occlusion? An Alberta Stroke Programme Early CT Score-based study

PURPOSE

Recent studies postulate a high prognostic value of the Alberta Stroke Programme Early CT Score (ASPECTS) applied on non-contrast whole-brain flat-detector CT (FDCT) after successful endovascular treatment (EVT). The aim of this study was the evaluation of long-term patient outcome after endovascular treatment using postinterventional FDCT.

METHODS

Using a local database (Stroke Research Consortium in Northern Bavaria, STAMINA), 517 patients with successful endovascular treatment (modified Thrombolysis in Cerebral Infarction (mTICI) ≥ 2B) due to acute ischaemic stroke (AIS) and large vessel occlusion (LVO) of the anterior circulation were recruited retrospectively. In all cases, non-contrast FDCT after EVT was analysed with special focus at ASPECTS. These results were correlated with the functional outcome in long-term (modified Rankin Scale (mRS) shift from pre-stroke to 90 days after discharge).

RESULTS

A significant difference in FDCT-ASPECTS compared to the subgroup of favourable vs. unfavourable outcome (Δ mRS) (median ASPECTS 10 (10-9) vs. median ASPECTS 9 (10-7); p = 0,001) could be demonstrated. Multivariable regression analysis revealed FDCT-ASPECTS (OR 0.234, 95% CI - 0.102-0.008, p = 0.022) along with the NHISS at admission (OR 0.169, 95% CI 0.003-0.018, p = 0.008) as independent factors for a favourable outcome. Cut-off point for a favourable outcome (Δ mRS) was identified at an ASPECTS ≥ 8 (sensitivity 90.6%, specificity 35%).

CONCLUSION

For patients with LVO and successful EVT, FDCT-ASPECTS was found to be highly reliable in predicting long-term outcome.

Elevated Blood Alcohol Concentration Is Associated with Improved Clinical Outcomes of Intravenous Thrombolysis Treatment in Acute Ischemic Stroke Patients—A Retrospective Study

Background: Intravenous thrombolysis (IVT) improves acute ischemic stroke (AIS) outcomes, but with limited success. In addition, ethanol potentiates the effect of r-tPA in ischemia models. Methods: The effect of acute alcohol consumption on IVT outcomes was investigated in a retrospective cohort study. AIS patients with detectable blood alcohol concentration (BAC) during IVT were included (alcohol group; n = 60). For each case, 3 control subjects who underwent IVT but denied alcohol consumption were matched in terms of age, sex, affected brain area, and stroke severity. Outcomes were determined using the NIHSS at 7 days and the modified Rankin scale (mRS) at 90 days. Results: Patients were younger and had a less severe stroke than in a standard stroke study. Favorable long-term outcomes (mRS 0–2) occurred significantly more frequently in the alcohol group compared to controls (90% vs. 63%, p < 0.001). However, the rates of hemorrhagic transformation were similar. Multiple logistic regression models identified elevated BAC as a significant protective factor against unfavorable short-term (OR: 0.091, 95% CI: 0.036–0.227, p < 0.001) and long-term outcomes (OR: 0.187, 95% CI: 0.066–0.535, p = 0.002). In patients with BAC > 0.2%, significantly lower NIHSS was observed at 3 and 7 days after IVT vs. in those with 0.01–0.2% ethanol levels. Conclusion: Elevated BAC is associated with improved outcomes in IVT-treated AIS without affecting safety.

Childhood Cerebral Vasculitis : A Multidisciplinary Approach

Cerebral vasculitis is increasingly recognized as a common cause of pediatric arterial stroke. It can present with focal neurological deficits, psychiatric manifestations, seizures, and encephalopathy. The etiopathogenesis of childhood cerebral vasculitis (CCV) is multifactorial, making an inclusive classification challenging. In this review, we describe the common and uncommon CCV with a comprehensive discussion of etiopathogenesis, the role of various imaging modalities, and advanced techniques in diagnosing CCV. We also highlight the implications of relevant clinical, laboratory, and genetic findings to reach the final diagnosis. Based on the clinicoradiological findings, a stepwise diagnostic approach is proposed to facilitate CCV diagnosis and rule out potential mimics. Identification of key clinical manifestations, pertinent blood and cerebrospinal fluid results, and evaluation of central nervous system vessels for common and disease-specific findings will be emphasized. We discuss the role of magnetic resonance imaging, MR angiography, and vessel wall imaging as the imaging investigation of choice, and reservation of catheter angiography as a problem-solving tool. We emphasize the utility of brain and leptomeningeal biopsy for diagnosis and exclusion of imitators and masqueraders.

Value of pre-intervention computed tomography perfusion imaging in the assessment of tissue outcome and long-term clinical prognosis in patients with anterior circulation acute ischemic stroke receiving reperfusion therapy: a systematic review

BACKGROUND

Computed tomography perfusion (CTP) imaging has emerged as an important adjunct to the current armamentarium of acute ischemic stroke (AIS) workflow. However, its adoption in routine clinical practice is far from optimal.

PURPOSE

To investigate the putative association of CTP imaging biomarkers in the assessment of prognosis in acute ischemic stroke.

MATERIAL AND METHODS

We performed a systematic review of the literature using MEDLINE, EMBASE, and Cochrane Central Register of Clinical Trials focusing on CTP biomarkers, tissue-based and clinical-based patient outcomes. We included randomized controlled trials, prospective cohort studies, and case-controlled studies published from January 2005 to 28 August 2020. Two independent reviewers conducted the study appraisal, data extraction, and quality assessment of the studies.

RESULTS

A total of 60 full-text studies were included in the final systematic review analysis. Increasing infarct core volume is associated with reduced odds of achieving functional independence (modified Rankin score 0-2) at 90 days and is correlated with the final infarct volume when reperfusion is achieved.

CONCLUSION

CTP has value in assessing tissue perfusion status in the hyperacute stroke setting and the long-term clinical prognosis of patients with AIS receiving reperfusion therapy. However, the prognostic use of CTP requires optimization and further validation.

High Neutrophil-Lymphocyte Ratio and Low Lymphocyte-Monocyte Ratio Combination after Thrombolysis Is a Potential Predictor of Poor Functional Outcome of Acute Ischemic Stroke

(1) Background: Ischemic stroke is one of the leading causes of death and disability. An inflammatory response is observed in multiple stages of cerebral ischemia, particularly in the acute phase. Recent publications revealed that the neutrophil−lymphocyte ratio (NLR) and lymphocyte−monocyte ratio (LMR) may be used to predict long-term prognosis in acute ischemic stroke (AIS) after thrombolysis. To test whether there is a relationship between the combination of these parameters and long-term prognosis, we analyzed the NLR−LMR combination in AIS patients treated with intravenous recombinant tissue plasminogen activator (rtPA); (2) Methods: The study included 285 adults with a diagnosis of AIS and rtPA treatment within a 4.5 h time window. Blood samples were obtained at admission and 24 h after thrombolysis to calculate pre- and post-thrombolysis NLR and LMR. Clinical data, including NIHSS was registered on admission and day 1. The long-term outcome was defined 90 days post-event by the modified Rankin Scale (mRS). Therapy-associated intracranial hemorrhage (ICH) was classified according to ECASS II. Receiver operating characteristic curve (ROC) analysis was performed to determine optimal cutoffs of NLR and LMR as predictors of therapy outcomes; (3) Results: Patients were stratified by cutoffs of 5.73 for NLR and 2.08 for LMR. The multivariate logistic regression model, including all possible confounders, displayed no significant association between NLR or LMR with 3-months functional prognosis. The combination of high NLR−low LMR vs. low NRL−high LMR as obtained 24 h after thrombolysis was found to be an independent predictor of poor 3-months functional outcome (mRS ≥ 2; OR 3.407, 95% CI 1.449 to 8.011, p = 0.005). The proportion of patients between low NLR−high LMR and high NLR−low LMR groups from admission to day 1 showed no significant change in the good outcome group. On the other hand, in the poor outcome group (mRS ≥ 2), low NLR−high LMR and high NLR−low LMR groups displayed a significant shift in patient proportions from 67% and 21% at admission (p = 0.001) to 36% and 49% at 24 h after thrombolysis (p < 0.001), respectively; (4) Conclusions: Our study demonstrated for the first time that a high NLR−low LMR combination as observed at 24 h after thrombolysis can serve as an independent predictor of 3-months poor outcome in AIS patients. This simple and readily available data may help clinicians to improve the prognostic estimation of patients and may provide guidance in selecting patients for personalized and intensified care post-thrombolysis.

Low α2-Plasmin Inhibitor Antigen Levels on Admission Are Associated With More Severe Stroke and Unfavorable Outcomes in Acute Ischemic Stroke Patients Treated With Intravenous Thrombolysis

Background

Intravenous administration of recombinant tissue plasminogen activator (rt-PA) fails to succeed in a subset of acute ischemic stroke (AIS) patients, while in approximately 6–8% of cases intracerebral hemorrhage (ICH) occurs as side effect.

Objective

Here, we aimed to investigate α2-plasmin inhibitor (α2-PI) levels during thrombolysis and to find out whether they predict therapy outcomes in AIS patients.

Patients/Methods

In this prospective, observational study, blood samples of 421 AIS patients, all undergoing i.v. thrombolysis by rt-PA within 4.5 h of their symptom onset, were taken before and 24 h after thrombolysis. In a subset of patients (n = 131), blood was also obtained immediately post-lysis. α2-PI activity and antigen levels were measured by chromogenic assay and an in-house ELISA detecting all forms of α2-PI. α2-PI Arg6Trp polymorphism was identified in all patients. Stroke severity was determined by NIHSS on admission and day 7. Therapy-associated ICH was classified according to ECASSII. Long-term outcomes were defined at 3 months post-event by the modified Rankin Scale (mRS).

Results

Median α2-PI activity and antigen levels showed a significant drop immediately post-lysis and increased to subnormal levels at 24 h post-event. Admission α2-PI levels showed a significant negative stepwise association with stroke severity. Patients with favorable long-term outcomes (mRS 0–1) had significantly higher admission α2-PI antigen levels (median:61.6 [IQR:55.9–70.5] mg/L) as compared to patients with poor outcomes (mRS 2–5: median:59.7 [IQR:54.5–69.1] and mRS 6: median:56.0 [IQR:48.5–61.0] mg/L, p < 0.001). In a Kaplan–Meier survival analysis, patients with an α2-PI antigen in the highest quartile on admission showed significantly better long-term survival as compared to those with α2-PI antigen in the lowest quartile (HR: 4.54; 95%CI:1.92–10.8, p < 0.001); however, in a multivariate analysis, a low admission α2-PI antigen did not prove to be an independent risk factor of poor long-term outcomes. In patients with therapy-related ICH (n = 34), admission α2-PI antigen levels were significantly, but only marginally, lower as compared to those without hemorrhage.

Conclusions

Low α2-PI antigen levels on admission were associated with more severe strokes and poor long-term outcomes in this cohort. Our results suggest that in case of more severe strokes, α2-PI may be involved in the limited efficacy of rt-PA thrombolysis.

Multi-Mode Imaging Scale for Endovascular Therapy in Patients with Acute Ischemic Stroke (META)

Background: With the guidance of multi-mode imaging, the time window for endovascular thrombectomy (EVT) has been expanded to 24 h. However, poor clinical outcomes are still not uncommon. We aimed to develop a multi-mode imaging scale for endovascular therapy in patients with acute ischemic stroke (META) to predict the neurological outcome in patients receiving endovascular thrombectomy (EVT). Methods: We included consecutive acute ischemic stroke patients with occlusion of middle cerebral artery and/or internal carotid artery who underwent EVT. Poor outcome was defined as modified Rankin Scale (mRS) score of 3−6 at 3 months. A five-point META score was constructed based on clot burden score, multi-segment clot, the Alberta Stroke Program early computed tomography score of cerebral blood volume (CBV-ASPECTS), and collateral status. We evaluated the META score performance using area under the curve (AUC) calculations. Results: A total of 259 patients were included. A higher META score was independently correlated with poor outcomes at 3 months (odds ratio, 1.690, 95% CI, 1.340 to 2.132, p < 0.001) after adjusting for age, hypertension, baseline National Institutes of Health Stroke Scale (NIHSS) score, and baseline blood glucose. Patients with a META score ≥ 2 were less likely to benefit from EVT (mRS 3−6: 60.8% vs. 29.2%, p < 0.001). The META score predicted poor outcomes with an AUC of 0.714, higher than the Pittsburgh Response to Endovascular therapy (PRE) score, the totaled health risks in vascular events (THRIVE) score (AUC: 0.566, 0.706), and the single imaging marker in the scale. Conclusions: The novel META score could refine the predictive accuracy of prognosis after EVT, which might provide a promising avenue for future automatic imaging analysis to help decision making.

Factors Associated with Unfavorable Functional Outcomes After Intravenous Thrombolysis in Patients with Acute Ischemic Stroke

Purpose

Intravenous thrombolysis (IVT) has become a standard treatment for eligible ischemic stroke patients. However, functional outcomes after receiving IVT varied widely. Hence the primary goal of this study is to identify characteristics related to poor outcomes.

Patients and Methods

The study enrolled acute ischemic stroke patients aged 18 or older who received IVT within 4.5 hours after onset between January 2018 and December 2020. The data were retrospectively collected from medical records. The patients were classified as having an excellent (0–2) or poor (3–6) outcomes based on the 90-day modified Rankin Scale (mRS). Univariable and multivariable logistic regression analyses were used to evaluate the results. The predictive model was determined and developed the score using regression coefficients. The prediction power was validated using the area under the receiver operating characteristic curve analysis.

Results

The study included 138 eligible participants. Forty-eight patients had unfavorable functional outcomes. With multivariable logistic regression analysis, factors significantly associated with poor outcomes were age (adjusted odds ratio (AOR), 1.03; 95% confidence interval (CI), 0.99–1.07; P = 0.05), diabetes (3.96; 1.61–9.37; P = 0.003), admission National Institute of Health Stroke Scale (NIHSS) (1.08; 1.01–1.15; P = 0.02) and initial Alberta Stroke Program Early Computed Tomography Score (ASPECTS) (0.56; 0.37–0.86; P = 0.009). The predictive model developed from the findings demonstrated good discrimination power (AuROC 0.803, 95% CI 0.728–0.877).

Conclusion

The current study found that older age, diabetes, atrial fibrillation, higher admission NIHSS, and lower ASPECTS on the initial NCCT brain were related to unfavorable functional outcomes following IVT and served as good predictors of patient functional outcomes.

Effects of Repetitive Peripheral Sensory Stimulation in the Subacute and Chronic Phases After Stroke: Study Protocol for a Pilot Randomized Trial

Background

Repetitive peripheral nerve sensory stimulation (RPSS) is a potential add-on intervention to motor training for rehabilitation of upper limb paresis after stroke. Benefits of RPSS were reported in subjects in the chronic phase after stroke, but there is limited information about the effects of this intervention within the 1st weeks or months. The primary goal of this study is to compare, in a head-to-head proof-of-principle study, the impact of a single session of suprasensory vs. subsensory RPSS on the upper limb motor performance and learning in subjects at different phases after stroke subacute and chronic phases and mild upper limb motor impairments after stroke. In addition, we examine the effects of RPSS on brain perfusion, functional imaging activation, and γ-aminobutyric acid (GABA) levels. Subjects with mild upper limb motor impairments will be tested with MRI and clinical assessment either at an early (7 days to 3 months post-stroke) or at a chronic (>6 months) stage after stroke.

Methods

In this multicenter, randomized, parallel-group, proof-of-principle clinical trial with blinded assessment of outcomes, we compare the effects of one session of suprasensory or subsensory RPSS in patients with ischemic or hemorrhagic stroke and upper limb paresis. Clinical assessment and MRI will be performed only once in each subject (either at an early or at a chronic stage). The primary outcome is the change in performance in the Jebsen–Taylor test. Secondary outcomes: hand strength, cerebral blood flow assessed with arterial spin labeling, changes in the blood oxygenation level-dependent (BOLD) effect in ipsilesional and contralesional primary motor cortex (M1) on the left and the right hemispheres assessed with functional MRI (fMRI) during a finger-tapping task performed with the paretic hand, and changes in GABA levels in ipsilesional and contralesional M1 evaluated with spectroscopy. The changes in outcomes will be compared in four groups: suprasensory, early; subsensory, early; suprasensory, chronic; and subsensory, chronic.

Discussion

The results of this study are relevant to inform future clinical trials to tailor RPSS to patients more likely to benefit from this intervention.

Trial Registration

NCT03956407.

Head CT in centenarians: emergency and non-emergency findings

INTRODUCTION

Our retrospective study evaluates head CTs performed in our Hospital in the last 11 years (2009-2019) in centenarian patients.

OBJECTIVES

To estimate the correlation between reasons for examination and CT findings in emergency and to evaluate if there was the expected involution of the brain by analyzing some non-emergency neuroradiological parameters (NENP).

MATERIAL AND METHODS

62 Head CTs performed on patients aged 100 and over were reviewed. They were evaluated emergency CT findings and NENP (leukoencephalopathy, enlargement of the ventricular volume, presence of vascular calcifications). For comparison, NENP were also assessed in two relatively younger populations of 62 patients aged between 65-70 (called "65-70") and 85-90 ("85-90").

RESULTS

In cases of suspected traumatic brain lesions, 11.9% (n = 5/42) of centenarians showed a cerebral bleeding; as concerns suspected stroke we found a higher concordance between clinical suspicion and CT features, 46.6% (n = 7/15). As regards NENP, no significant differences were found with respect to the "85-90" population in terms of severity of leukoencephalopathy, enlargement of the ventricular volume and presence of vascular calcifications.

CONCLUSIONS

In emergency, CT plays a pivotal role in defining an immediate diagnosis and from a medico-legal point of view, resulting together with clinical observation the main strategy in the management of centenarians. By the analysis of NENP we may support that centenarians' brains on CT are similar to those of "85-90".

Value of pre-intervention CT perfusion imaging in acute ischemic stroke prognosis

Noninvasive imaging plays an important role in acute stroke towards diagnosis and ongoing management of patients. Systemic thrombolysis and endovascular thrombectomy (EVT) are proven treatments currently used in standards of care in acute stroke settings. The role of computed tomography angiography (CTA) in selecting patients with large vessel occlusion for EVT is well established. However, the value of CT perfusion (CTP) imaging in predicting outcomes after stroke remains ambiguous. This article critically evaluates the value of multimodal CT imaging in early diagnosis and prognosis of acute ischemic stroke with a focus on the role of CTP in delineating tissue characteristics, patient selection, and outcomes after reperfusion therapy. Insights on various technical and clinical considerations relevant to CTP applications in acute ischemic stroke, recommendations for existing workflow, and future areas of research are discussed.

Predictors of motor outcome after childhood arterial ischemic stroke

AIM

To identify clinical and radiological predictors of long-term motor outcome after childhood-onset arterial ischemic stroke (AIS) in the middle cerebral artery (MCA) territory.

METHOD

Medical records of 69 children (36 females, 33 males; median age at index AIS 3y 3mo, range: 1mo-16y) who presented to Great Ormond Street Hospital with first AIS in the MCA territory were reviewed retrospectively. Cases were categorized using the Childhood AIS Standardized Classification and Diagnostic Evaluation (CASCADE). Magnetic resonance imaging (MRI) and angiography were evaluated. An Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was calculated on MRI. The Recurrence and Recovery Questionnaire assessed motor outcome and was dichotomized into good/poor.

RESULTS

Eventual motor outcome was good in 49 children and poor in 20. There were no acute radiological predictors of eventual motor outcome. At follow-up, CASCADE 3A (i.e. moyamoya) and Wallerian degeneration were significantly associated with poor motor outcome. In the multivariate analysis, younger age and CASCADE 3A predicted poor motor outcome.

INTERPRETATION

In the context of recommendations regarding unproven and potentially high-risk hyperacute therapies for childhood AIS, prediction of outcome could usefully contribute to risk/benefit analysis. Unfortunately, paradigms used in adults, such as ASPECTS, are not useful in children in the acute/early subacute phase of AIS. What this paper adds Adult paradigms, such as the Alberta Stroke Program Early Computed Tomography Score system, are not useful for predicting outcome in children. Younger children tend to have a poorer long-term prognosis than older children. Moyamoya is associated with poor prognosis.

Decreased clot burden is associated with factor XIII Val34Leu polymorphism and better functional outcomes in acute ischemic stroke patients treated with intravenous thrombolysis

BACKGROUND

Intravenous thrombolysis using recombinant tissue plasminogen activator remains the mainstay treatment of acute ischemic stroke (AIS), although endovascular treatment is becoming standard of care in case of large vessel occlusions (LVO). To quantify the thrombus burden in LVO, a semiquantitative CT angiography (CTA) grading system, the clot burden score (CBS) can be used. Here we aimed to study the association between CBS and various hemostasis parameters, and to evaluate which parameters are major determinants of thrombolysis outcome.

METHODS

In this single-centered prospective observational case-control study, 200 anterior circulation AIS patients receiving intravenous thrombolysis treatment without thrombectomy were enrolled: 100 AIS patients with LVO (CBS 0-9) and 100 age- and sex-matched AIS patients without LVO (CBS 10). Fibrinogen, α2-plasmin inhibitor, plasminogen, factor XIII and D-dimer were assessed from blood samples taken before and 24 h after thrombolysis, and FXIII-A Val34Leu was genotyped. CBS was calculated using admission CTA. Short-term outcomes were defined based on the change in NIHSS by day 7, long-term outcomes were assessed according to the modified Rankin scale at 3 months post-event.

RESULTS

Poor outcomes were significantly more frequent in the CBS 0-9 group. Plasminogen activity on admission was significantly higher in the CBS 0-9 group. In a univariate analysis, significant protective effect of the Leu34 allele against developing larger clots (CBS 0-9) could be demonstrated (OR:0.519; 95%CI:0.298-0.922, p = 0.0227). Multivariate regression analysis revealed that CBS is an independent predictor of short- and long-term functional outcomes, while such effect of the studied hemostasis parameters could not be demonstrated.

CONCLUSIONS

CBS was found to be a significant independent predictor of thrombolysis outcomes. FXIII-A Leu34 carrier status was associated with smaller thrombus burden, which is consistent with the in vitro described whole blood clot mass reducing effects of the allele, but the polymorphism had no effect on thrombolysis outcomes.

A modified in vitro clot lysis assay predicts outcomes and safety in acute ischemic stroke patients undergoing intravenous thrombolysis

The outcome of intravenous thrombolysis using recombinant tissue plasminogen activator (rt-PA) is only favorable in ≈ 40% of acute ischemic stroke (AIS) patients. Moreover, in ≈ 6-8% of cases, intracerebral hemorrhage (ICH) develops. We tested whether a modification of clot lysis assay (CLA), might predict therapy outcomes and safety. In this prospective observational study, blood samples of 231 AIS patients, all receiving intravenous rt-PA, were taken before thrombolysis. Cell-free DNA (cfDNA), CLA and CLA supplemented with cfDNA and histones (mCLA) were determined from the blood samples. Stroke severity was determined by NIHSS on admission. ICH was classified according to ECASSII. Short- and long-term outcomes were defined at 7 and 90 days post-event according to ΔNIHSS and by the modified Rankin Scale, respectively. Stroke severity demonstrated a step-wise positive association with cfDNA levels, while a negative association was found with the time to reach 50% lysis (50%CLT) parameter of CLA and mCLA. ROC analysis showed improved diagnostic performance of the mCLA. Logistic regression analysis proved that 50%CLT is a predictor of short-term therapy failure, while the AUC parameter predicts ICH occurrence. A modified CLA, supplemented with cfDNA and histones, might be a promising tool to predict short-term AIS outcomes and post-lysis ICH.

New Focus on Endovascular Therapy for Ischemic Stroke

BACKGROUND

Over the past 2 decades, a growing number of large-scale clinical trials have helped expand the toolkit for emergency management of acute ischemic stroke. This article is intended to be an up-to-date resource to aid nonstroke specialist neurology providers and ophthalmologists in identifying situations and patient populations in which urgent stroke evaluation should be completed with options for emergent reperfusion therapy considered.

EVIDENCE ACQUISITION

The literature forming the foundation of the guidelines for early management of patients with acute ischemic stroke was reviewed, annotated, and summarized.

RESULTS

Data from both initial and follow-up trials investigating the benefits and indications for use of intravenous thrombolysis and endovascular intervention for stroke are reviewed systematically, with an emphasis on new updates to qualifying patient populations and time periods for treatment.

CONCLUSIONS

Recent studies underscore the conclusion that timely reperfusion in acute ischemic stroke is the most effective available treatment and that there are a growing number of new scenarios and patients for which interventions maybe applied.

Assistance from Automated ASPECTS Software Improves Reader Performance

PURPOSE

To compare physicians' ability to read Alberta Stroke Program Early CT Score (ASPECTS) in patients with a large vessel occlusion within 6 hours of symptom onset when assisted by a machine learning-based automatic software tool, compared with their unassisted score.

MATERIALS AND METHODS

50 baseline CT scans selected from two prior studies (CRISP and GAMES-RP) were read by 3 experienced neuroradiologists who were provided access to a follow-up MRI. The average ASPECT score of these reads was used as the reference standard. Two additional neuroradiologists and 6 non-neuroradiologist readers then read the scans both with and without assistance from the software reader-augmentation program and reader improvement was determined. The primary hypothesis was that the agreement between typical readers and the consensus of 3 expert neuroradiologists would be improved with software augmented vs. unassisted reads. Agreement was based on the percentage of the individual ASPECT regions (50 cases, 10 regions each; N=500) where agreement was achieved.

RESULTS

Typical non-neuroradiologist readers agreed with the expert consensus read in 72% of the 500 ASPECTS regions, evaluated without software assistance. The automated software alone agreed in 77%. When the typical readers read the scan in conjunction with the software, agreement improved to 78% (P<0.0001, test of proportions). The software program alone achieved correlations for total ASPECT scores that were similar to the expert readers who had access to the follow-up MRI scan to help enhance the quality of their reads.

CONCLUSION

Typical readers had statistically significant improvement in their scoring of scans when the scan was read in conjunction with the automated software, achieving agreement rates that were comparable to neuroradiologists.

CT perfusion based ASPECTS improves the diagnostic performance of early ischemic changes in large vessel occlusion

Background

ASPECTS scoring method varies, but which one is most suitable for predicting the prognosis still unclear. We aimed to evaluate the diagnostic performance of Automated (Auto)-, noncontrast CT (NCCT)- and CT perfusion (CTP) -ASPECTS for early ischemic changes (EICs) in acute ischemic stroke patients with large vessel occlusion (LVO) and to explore which scoring method is most suitable for predicting the clinical outcome.

Methods

Eighty-one patients with anterior circulation LVO were retrospectively enrolled and grouped as having a good (0–2) or poor (3–6) clinical outcome using a 90-day modified Rankin Scale score. Clinical characteristics and perfusion parameters were compared between the patients with good and poor outcomes. Differences in scores obtained with the three scoring methods were assessed. Diagnosis performance and receiver operating characteristic (ROC) curves were used to evaluate the value of the three ordinal or dichotomized ASPECTS methods for predicting the clinical outcome.

Results

Sixty-three patients were finally included, with 36 (57.1%) patients having good clinical outcome. Significant differences were observed in the ordinal or dichotomized Auto-, NCCT- and CTP-ASPECTS between the patients with good and poor clinical outcomes (all p < 0.01). The areas under the curves (AUCs) of the ordinal and dichotomized CTP-ASPECTS were higher than that of the other two methods (all p < 0.01), but the AUCs of the Auto-ASPECTS was similar to that of the NCCT-ASPECTS (p > 0.05).

Conclusions

The CTP-ASPECTS is superior to the Auto- and NCCT-ASPECTS in detecting EICs in LVO. CTP-ASPECTS with a cutoff value of 6 is a good predictor of the clinical outcome at 90-day follow-up.

Impact of Delirium and Its Motor Subtypes on Stroke Outcomes

BACKGROUND AND PURPOSE

Delirium is an acute and fluctuating impairment of attention, cognition, and behavior. Although common in stroke, studies that associate the clinical subtypes of delirium with functional outcome and death are lacking. We aimed to evaluate the influence of delirium occurrence and its different motor subtypes over stroke patients' prognosis.

METHODS

Prospective cohort of stroke patients with symptom onset within 72 hours before research admission. Delirium was diagnosed by Confusion Assessment Method for the Intensive Care Unit, and its motor subtypes were defined according to the Richmond Agitation-Sedation Scale. The main outcome was functional dependence or death (modified Rankin Scale>2) at 90 days comparing: delirium versus no delirium patients; and between motor subtypes. Secondary outcomes included modified Rankin Scale score >2 at 30 days and 90-day-mortality.

RESULTS

Two hundred twenty-seven patients were enrolled. Delirium occurred in 71 patients (31.3%), with the hypoactive subtype as the most frequent, in 41 subjects (57.8%). Delirium was associated with increased risk of death and functional dependence at 30 and 90 days and higher 90-day mortality. Multivariate analysis showed delirium (odds ratio, 3.28 [95% CI, 1.17-9.22]) as independent predictor of modified Rankin Scale >2 at 90 days.

CONCLUSIONS

Delirium is frequent in stroke patients in the acute phase. Its occurrence-specifically in mixed and hypoactive subtypes-seems to predict worse outcomes in this population. To our knowledge, this is the first study to prospectively investigate differences between delirium motor subtypes over functional outcome three months poststroke. Larger studies are needed to elucidate the relationship between motor subtypes of delirium and functional outcomes in the context of acute stroke.

Decompressive craniectomy in malignant MCA infarction in times of mechanical thrombectomy

BACKGROUND

Mechanical thrombectomies (MT) in stroke have changed the standard treatment regimen with a continuous increase of MTs during the last years. A subsequent reduction in the rates of decompressive craniectomies (DC) as well as a change in clinical characteristics of patients undergoing an additional DC after MT may be assumed. Therefore, objective of this study was to investigate the influence of nowadays regularly performed MT on patients undergoing DC.

METHODS

Patients with DC due to cerebral infarctions between January 2009 and January 2018 were included. Patients' clinical presentation and surgical parameters were collected retrospectively. Initial GCS and NIHSS, extent of the stroke, time interval from symptom onset to DC, and neurological outcome were compared between patients with and without thrombectomy.

RESULTS

A total of 5469 ischemic strokes were treated in the investigated period, leading to DC in 119 cases (2.2%). A decrease in the rate of performed DCs was recorded: in 2009, 2.8% of ischemic stroke patients underwent surgery compared to 1.9% in 2017. In the meantime, the number of MTs in our center has increased from 84 in 2014 to 160 in 2017. MT was performed in 32 patients prior to DC. No significant differences could be seen between the groups regarding age, initial NIHSS (median 18 in both groups, p = 0.81), extent of the infarctions prior to DC (median ASPECTS 0 in both groups, p = 0.87), time interval from symptom onset to DC, and neurological outcome.

CONCLUSIONS

The introduction of routinely performed MT as part of the standard treatment regimen for ischemic stroke has led to a decrease in DCs. However, DC patients with and without MT showed no differences regarding their initial clinical criteria and outcome. These results suggest that earlier DC studies in patients with MCA infarction also apply for the collective of thrombectomized patients.

Qualitative versus automatic evaluation of CT perfusion parameters in acute posterior circulation ischaemic stroke

Purpose

To compare the diagnostic accuracy (ACC) in the detection of acute posterior circulation strokes between qualitative evaluation of software-generated colour maps and automatic assessment of CT perfusion (CTP) parameters.

Methods

Were retrospectively collected 50 patients suspected of acute posterior circulation stroke who underwent to CTP (GE “Lightspeed”, 64 slices) within 24 h after symptom onset between January 2016 and December 2018. The Posterior circulation-Acute Stroke Prognosis Early CT Score (pc-ASPECTS) was used for quantifying the extent of ischaemic areas on non-contrast (NC)CT and colour-coded maps generated by CTP4 (GE) and RAPID (iSchemia View) software. Final pc-ASPECTS was calculated on follow-up NCCT and/or MRI (Philips Intera 3.0 T or Philips Achieva Ingenia 1.5 T). RAPID software also elaborated automatic quantitative mismatch maps.

Results

By qualitative evaluation of colour-coded maps, MTT-CTP4D and Tmax-RAPID showed the highest sensitivity (SE) (88.6% and 90.9%, respectively) and ACC (84% and 88%, respectively) compared with the other perfusion parameters (CBV, CBF). Baseline NCCT and CBF provided by RAPID quantitative perfusion mismatch maps had the lowest SE (29.6% and 6.8%, respectively) and ACC (38% and 18%, respectively). CBF and Tmax assessment provided by quantitative RAPID perfusion mismatch maps showed significant lower SE and ACC than qualitative evaluation. No significant differences were found between the pc-ASPECTSs assessed on colour-coded MTT and Tmax maps neither between the scores assessed on colour-coded CBV-CTP4D and CBF-RAPID maps.

Conclusion

Qualitative analysis of colour-coded maps resulted more sensitive and accurate in the detection of ischaemic changes than automatic quantitative analysis.

Detection of ischemic changes on baseline multimodal computed tomography: expert reading vs. Brainomix and RAPID software

PURPOSE

The aim of the study was to compare the assessment of ischemic changes by expert reading and available automated software for non-contrast CT (NCCT) and CT perfusion on baseline multimodal imaging and demonstrate the accuracy for the final infarct prediction.

METHODS

Early ischemic changes were measured by ASPECTS on the baseline neuroimaging of consecutive patients with anterior circulation ischemic stroke. The presence of early ischemic changes was assessed a) on NCCT by two experienced raters, b) on NCCT by e-ASPECTS, and c) visually on derived CT perfusion maps (CBF<30%, Tmax>10s). Accuracy was calculated by comparing presence of final ischemic changes on 24-hour follow-up for each ASPECTS region and expressed as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The subanalysis for patients with successful recanalization was conducted.

RESULTS

Of 263 patients, 81 fulfilled inclusion criteria. Median baseline ASPECTS was 9 for all tested modalities. Accuracy was 0.76 for e-ASPECTS, 0.79 for consensus, 0.82 for CBF<30%, 0.80 for Tmax>10s. e-ASPECTS, consensus, CBF<30%, and Tmax>10s had sensitivity 0.41, 0.46, 0.49, 0.57, respectively; specificity 0.91, 0.93, 0.95, 0.91, respectively; PPV 0.66, 0.75, 0.82, 0.73, respectively; NPV 0.78, 0.80, 0.82, 0.83, respectively. Results did not differ in patients with and without successful recanalization.

CONCLUSION

This study demonstrated high accuracy for the assessment of ischemic changes by different CT modalities with the best accuracy for CBF<30% and Tmax>10s. The use of automated software has a potential to improve the detection of ischemic changes.

Acute Ischemic Stroke: Acute Management and Selection for Endovascular Therapy

Stroke is a medical emergency and expeditious treatment is critical to reducing permanent disability or death. Acute management of patients suffering from acute ischemic stroke (AIS) requires early recognition of symptoms, rapid assessment and stabilization (hyperacute workup), and appropriate selection of patients for reperfusion with intravenous alteplase and/or mechanical thrombectomy. Established stroke protocols which involve both prehospital emergency medical services and in-hospital multidisciplinary stroke teams have been shown to be crucial to reducing the long term, devastating effects of stroke.

Deciding Thrombolysis in AIS Based on Automated versus on WhatsApp Interpreted ASPECTS, a Reliability and Cost-Effectiveness Analysis in Developing System of Care

Background: Automated ASPECTS has the potential of reducing interobserver variability in the determination of early ischemic changes. We aimed to assess the performance of an automated ASPECTS vs. ASPECTS interpreted for sent CT images on WhatsApp and to correlate these results with the outcome. Materials and Methods: Patients with anterior circulation stroke who had baseline NCCT and underwent successful IV-thrombolysis were included. NCCT-ASPECTS was assessed by two neuroradiologists, and discrepancies were resolved by agreement. Two groups of patients were included; group 1, where treatment was decided after an automated ASPECTS interpretation that was provided by RAPID software, and group 2, where patients received IV-tPA after an assessment of CT images sent on WhatsApp. Results: A total of 122 patients were included: 36 in group 1 and 86 in group 2. In group 2, the interobserver agreement for NCCT ASPECTS was moderate (κ = 0.36), as was the dichotomized data (κ = 0.44). IOA, however, improved (to κ = 0.57 and κ = 0.64) when the same CT images were interpreted on a workstation. In group 1, Automated ASPECTS showed excellent agreement (κ = 0.80) with agreement reads for workstation images. There were significantly (P < 0.001) increased odds of functional independence and fewer hemorrhagic complications with thrombolyzed patients in group 1. Conclusions: Automated ASPECTS provided by the RAPID@IschemaView ASPECTS performs at a level equal to the agreement read of expert neuroradiologists, and this performance was severely degraded when WhatsApp captured CT images used for ASPECTS assessment. In our study, we found that automated ASPECTS might predict outcomes after IV thrombolysis.

Methylprednisolone pulse therapy as an adjuvant treatment of Streptococcus pneumoniae meningitis complicated by cerebral infarction-a case report and review of the literature

PURPOSE

The role of methylprednisolone pulse therapy as adjuvant treatment of Streptococcus pneumoniae meningitis complicated by cerebral infarction has rarely been reported.

METHODS

We reported a case report and also performed a systematic literature review.

RESULTS

A 1-year 2-month-old boy who presented with high fever, status epilepticus, and septic shock was diagnosed with cerebral infarction caused by Streptococcus pneumoniae meningitis on magnetic resonance imaging (MRI). He was treated with methylprednisolone pulse therapy and his clinical condition gradually improved thereafter. At the follow-up visit 1 year after discharge, he was able to sit without support, but he had moderate delays in speech and developmental milestones and epilepsy sequelae.

CONCLUSION

In severe cases, the use of high-dose methylprednisolone should be considered to modulate the inflammatory response in patients with severe cerebral infarction caused by Streptococcus pneumoniae meningitis.

Observer Agreement on Computed Tomography Perfusion Imaging in Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Computed tomography (CT) perfusion (CTP) provides potentially valuable information to guide treatment decisions in acute stroke. Assessment of interobserver reliability of CTP has, however, been limited to small, mostly single center studies. We performed a large, internet-based study to assess observer reliability of CTP interpretation in acute stroke.

CerebroVis: Designing an Abstract yet Spatially Contextualized Cerebral Artery Network Visualization

Blood circulation in the human brain is supplied through a network of cerebral arteries. If a clinician suspects a patient has a stroke or other cerebrovascular condition, they order imaging tests. Neuroradiologists visually search the resulting scans for abnormalities. Their visual search tasks correspond to the abstract network analysis tasks of browsing and path following. To assist neuroradiologists in identifying cerebral artery abnormalities, we designed CerebroVis, a novel abstract-yet spatially contextualized-cerebral artery network visualization. In this design study, we contribute a novel framing and definition of the cerebral artery system in terms of network theory and characterize neuroradiologist domain goals as abstract visualization and network analysis tasks. Through an iterative, user-centered design process we developed an abstract network layout technique which incorporates cerebral artery spatial context. The abstract visualization enables increased domain task performance over 3D geometry representations, while including spatial context helps preserve the user's mental map of the underlying geometry. We provide open source implementations of our network layout technique and prototype cerebral artery visualization tool. We demonstrate the robustness of our technique by successfully laying out 61 open source brain scans. We evaluate the effectiveness of our layout through a mixed methods study with three neuroradiologists. In a formative controlled experiment our study participants used CerebroVis and a conventional 3D visualization to examine real cerebral artery imaging data to identify a simulated intracranial artery stenosis. Participants were more accurate at identifying stenoses using CerebroVis (absolute risk difference 13%). A free copy of this paper, the evaluation stimuli and data, and source code are available at osf.io/e5sxt.

Automated ASPECTS in Acute Ischemic Stroke: A Comparative Analysis with CT Perfusion

BACKGROUND AND PURPOSE

Automated ASPECTS has the potential of reducing interobserver variability in the determination of early ischemic changes. We aimed to assess the performance of an automated ASPECTS software against the assessment of a neuroradiologist in a comparative analysis with concurrent CTP-based CBV ASPECTS.

MATERIALS AND METHODS

Patients with anterior circulation stroke who had baseline NCCT and CTP and underwent successful mechanical thrombectomy were included. NCCT-ASPECTS was assessed by 2 neuroradiologists, and discrepancies were resolved by consensus. CTP-CBV ASPECTS was assessed by a different neuroradiologist. Automated ASPECTS was provided by Brainomix software. ASPECTS was dichotomized (ASPECTS ≥6 or <6) and was also based on the time from onset (>6 or ≤6 hours).

RESULTS

A total of 58 patients were included. The interobserver agreement for NCCT ASPECTS was moderate (κ = 0.48) and marginally improved (κ = 0.64) for dichotomized data. Automated ASPECTS showed excellent agreement with consensus reads (κ = 0.84) and CTP-CBV ASPECTS (κ = 0.84). Intraclass correlation coefficients for ASPECTS across all 3 groups were 0.84 (95% CI, 0.76-0.90, raw scores) and 0.94 (95% CI, 0.91-0.96, dichotomized scores). Automated scores were comparable with consensus reads and CTP-CBV ASPECTS in patients when grouped on the basis of time from symptom onset (>6 or ≤6 hours). There was significant (P < .001) negative correlation with final infarction volume and the 3 ASPECTS groups (r = -0.52, consensus reads; -0.58, CTP-CBV; and -0.66, automated).

CONCLUSIONS

ASPECTS derived from an automated software performs equally as well as consensus reads of expert neuroradiologists and concurrent CTP-CBV ASPECTS and can be used to standardize ASPECTS reporting and minimize interpretation variability.

PAI-1 5G/5G genotype is an independent risk of intracranial hemorrhage in post-lysis stroke patients

Objective

Thrombolysis by recombinant tissue plasminogen activator (rt‐PA) is the main pharmacological therapy in acute ischemic stroke (IS); however, it is only effective in a subset of patients. Here we aimed to investigate the role of plasminogen activator inhibitor‐1 (PAI‐1), an effective inhibitor of t‐PA, and its major polymorphism (PAI‐1 4G/5G) in therapy outcome.

Methods

Study population included 131 consecutive IS patients who all underwent thrombolysis. Blood samples were taken on admission, 1 and 24 h after rt‐PA infusion. PAI‐1 activity and antigen levels were measured from all blood samples and the PAI‐1 4G/5G polymorphism was determined. Clinical data including NIHSS were registered on admission and day 1. ASPECTS was assessed using CT images taken before and 24 h after thrombolysis. Intracranial hemorrhage (ICH) was classified according to ECASS II. Long‐term outcome was defined 90 days post‐event by the modified Rankin Scale (mRS).

Results

PAI‐1 activity levels dropped transiently after thrombolysis, while PAI‐1 antigen levels remained unchanged. PAI‐1 4G/5G polymorphism had no effect on PAI‐1 levels and did not influence stroke severity. PAI‐1 activity/antigen levels as measured on admission were significantly elevated in patients with worse 24 h ASPECTS (<7). Logistic regression analysis including age, sex, NIHSS on admission, BMI, history of arterial hypertension, and hyperlipidemia conferred a significant, independent risk for developing ICH in the presence of 5G/5G genotype (OR:4.75, 95%CI:1.18–19.06). PAI‐1 levels and PAI‐1 4G/5G polymorphism had no influence on long‐term outcomes.

Interpretation

PAI‐1 5G/5G genotype is associated with a significant risk for developing ICH in post‐lysis stroke patients.

Assessment of Cerebral Vasodilatory Capacity as Part of Catheter-Based Cerebral Angiography

BACKGROUND AND PURPOSE

Cerebral vasodilatory capacity assessment for risk stratification in patients with extracranial arterial stenosis or occlusion may be useful. We describe a new method that assesses cerebral vasodilatory capacity as part of catheter-based cerebral angiography.

METHODS

We prospectively assessed regional cerebral blood volume (rCBV) in the arterial distribution of interest using a controlled contrast injection in the common carotid or the subclavian arteries. rCBV maps were created using a predefined algorithm based on contrast distribution in the venous phase (voxel size: .466 mm³ ). rCBV maps were acquired again after selective administration of intra-arterial nicardipine (2.0 mg) distal to the stenosis. Two independent observers graded the change in rCBV in 10 predefined anatomical regions within the tributaries of the artery of interest (0 = reduction, 1 = no change, 2 = increase) and total rCBV change scores were summated.

RESULTS

Twenty-five patients with internal carotid artery stenosis (n = 18; 0-90% in severity) or extracranial vertebral artery stenosis (n = 7; 0-100% in severity) were assessed. There was an increase in rCBV in a tributary of the artery of interest in 18 of 25 after intra-arterial nicardipine (mean score: 11.98; range 0-19.5). There was no change or decrease in rCBV in 7 of 25 patients. The mean rCBV change score was similar in patients with an assessment of internal carotid artery or vertebral artery distributions (12.2 ± 5.3; 11.4 ± 2.5; P = .68).

CONCLUSION

Selective vasodilatory response to intra-arterial nicardipine in the affected arterial distribution during catheter-based cerebral angiography may provide new data for risk stratification.

Prognostic value of subclinical thyroid dysfunction in ischemic stroke patients treated with intravenous thrombolysis

Data regarding the association between subclinical thyroid dysfunction and clinical outcomes in ischemic stroke patients with intravenous thrombolysis (IVT) are limited. We aimed to investigate the predictive value of subclinical thyroid dysfunction in END, functional outcome and mortality at 3 months among IVT patients. We prospectively recruited 563 IVT patients from 5 stroke centers in China. Thyroid function status was classified as subclinical hypothyroidism, subclinical hyperthyroidism (SHyper) and euthyroidism. The primary outcome was END, defined as ≥ 4 point in the NIHSS score within 24 h after IVT. Secondary outcomes included 3-month functional outcome and mortality. Of the 563 participants, END occurred in 14.7%, poor outcome in 50.8%, and mortality in 9.4%. SHyper was an independent predictor of END [odd ratio (OR), 4.35; 95% confidence interval [CI], 1.86–9.68, P = 0.003], 3-month poor outcome (OR, 3.24; 95% CI, 1.43–7.33, P = 0.005) and mortality [hazard ratio, 2.78; 95% CI, 1.55–5.36, P = 0.003]. Subgroup analysis showed that there was no significant relationship between SHyper and clinical outcomes in IVT patients with endovascular therapy. In summary, SHyper is associated with increased risk of END, and poor outcome and mortality at 3 months in IVT patients without endovascular therapy.

Contrast Staining may be Associated with Intracerebral Hemorrhage but Not Functional Outcome in Acute Ischemic Stroke Patients Treated with Endovascular Thrombectomy

To evaluate the incidence of post-interventional contrast staining (PICS) in acute ischemic stroke (AIS) Chinese patients who were treated with endovascular thrombectomy (ET) and investigate potential association of PICS with functional outcome and intracerebral hemorrhage (ICH). This observational study was based on a single-center prospective registry study. AIS patients who underwent ET from January 2013 to February 2017 were recruited into this study. All patients had dual-energy CT (DECT) scan of the head at 12 to 24 hours post-ET. The primary outcome was the incidence of PICS. Secondary outcomes were total ICH, symptomatic ICH (sICH), 3-month functional outcome, and long-term functional outcome. One hundred and eighty patients were enrolled in this study. PICS was detected in 50 patients (28%) based on the post-interventional CT scan. We first used basic statistical analyses, showing that the incidence of both total ICH (60% vs. 25%, p<0.001) and sICH (18% vs. 8%, p=0.044) were higher in patients with PICS than those without, and fewer patients achieved no disability (mRS≤1) in the PICS group compared to the control group at both 3-month and long-term follow-up (p<0.01 each). However, multivariate regression analysis further revealed that PICS only increased total (adjusted odds ratio, 7.38; 95% confidence interval 1.66 to 32.9; p=0.009) but not sICH risk. Furthermore, the logistic regression analyses did not show statistical difference in good clinical outcomes or mortality between the two groups. PICS is a common phenomenon in Chinese AIS patients. It is associated with total ICH after ET, but it seems to have no effect on functional outcome and sICH. Further large-scale studies are warranted to validate these results.

Evaluating the Prognosis of Ischemic Stroke Using Low-Dose Multimodal Computed Tomography Parameters in Hyperacute Phase

PURPOSE

The aim of this study was to evaluate the potential value of low-dose multimodal computed tomography (CT) in predicting prognosis of acute ischemic stroke (AIS) within 6 hours.

METHODS

The admission "one-stop-shop" multimodal CT examination, including noncontrast CT (NCCT), low-dose CT perfusion, and CT angiography (CTA), was performed in patients with symptoms of stroke within 6 hours. Noncontrast CT, CTA source image (CTA-SI), cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and mean transit time (MTT) maps were studied using Alberta Stroke Program Early CT Score (ASPECTS). The regional leptomeningeal collateral (rLMC) score (0-20) was dichotomized into 2 groups: good (11-20) and poor (0-10) rLMC. Poor functional outcomes were defined by a modified Rankin scale score of 3 to 6.

RESULTS

One hundred forty-four patients were ultimately selected; 43.8% of them showed poor functional outcomes. They had lower ASPECTSs on NCCT, CTA-SI, CBV, CBF, TTP, and MTT, and poor rLMC was more frequently associated with poor functional outcomes (all P < 0.001). In the multivariate analysis for AIS patients with conservative treatment, CTA-SI-ASPECTS 6 or less (odds ratio [OR], 5.9; 95% confidence interval [95% CI], 1.9-18.4; P = 0.002) and poor collaterals (OR, 5.0; 95% CI, 1.3-15.4; P = 0.017), CBV-ASPECTS 6 or less (OR, 8.0; 95% CI, 2.7-24.0; P < 0.001), CBF-ASPECTS 4 or less (OR, 8.0; 95% CI, 2.0-31.5; P = 0.003), MTT-ASPECTS≤3 (OR, 5.8; 95% CI, 1.8-18.1; P = 0.003), TTP-ASPECTS 4 or less (OR, 5.0; 95% CI, 1.6-15.1; P = 0.005), and NCCT-ASPECTS 8 or less (OR, 5.9; 95% CI, 1.7-20.4; P = 0.005) were significantly associated with poor functional outcome. In the multivariate analysis for AIS patients with thrombolysis, CTA-SI-ASPECTS 6 or less (OR, 27.5; 95% CI, 2.9-262.3; P = 0.004), poor collaterals (OR, 28.0; 95% CI, 2.8-283.0; P < 0.028), and CBV-ASPECTS 6 or less (OR, 18.0; 95% CI, 3.0-107.7; P = 0.002) were associated with poor functional outcomes. Furthermore, the area under the curve (AUC) of the combination of CTA-SI-ASPECTS 6 or less, poor collaterals, and CBV-ASPECTS 6 or less (AUC, 0.87) was greater than that for any single parameter alone: CTA-SI-ASPECTS 6 or less (AUC, 0.80; P < 0.001), poor collaterals (AUC, 0.76; P < 0.001), and CBV-ASPECTS 6 or less (AUC, 0.81; P = 0.002).

CONCLUSIONS

The combination of CTA-SI-ASPECTS, collaterals, and CBV-ASPECTS may improve predictive power compared with a single parameter alone.

Unenhanced Dual-Energy Computed Tomography: Visualization of Brain Edema

PURPOSE

The aim of this study was to determine whether dual-energy computed tomography (DECT) imaging is superior to conventional noncontrast computed tomography (CT) imaging for the detection of acute ischemic stroke.

MATERIALS AND METHODS

This was a retrospective, single-center study of 40 patients who presented to the emergency department (ED) of a major, acute care, teaching center with signs and symptoms of acute stroke. Only those patients who presented to the ED within 4 hours of symptom onset were included in this study. All 40 patients received a noncontrast DECT of the head at the time of presentation. Each patient also received standard noncontrast CT of the head 24 hours after their initial presentation to the ED. "Brain edema" images were then reconstructed using 3-material decomposition with parameters adjusted to suppress gray/white matter contrast while preserving edema and increasing its conspicuity. The initial unenhanced, mixed images, brain edema, and 24-hour follow-up true noncontrast (TNC) images were reviewed and assigned Alberta Stroke Program Early CT scores. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

Of the 40 patients, 28 (70%) were diagnosed with an acute infarction. Brain edema reconstructions were better able to predict end infarction volume, with Alberta Stroke Program Early CT scores similar to the 24-hour follow-up TNC CT (7.75 vs 7.7; P > 0.05), whereas the mixed images routinely underestimated the extent of infarction (8.975 vs 7.7; P < 0.001). Initial TNC images had a sensitivity, specificity, PPV, and NPV of 80% (95% confidence interval [CI], 51.9%-95.7%), 72.7% (95% CI, 39%-94%), 80% (95% CI, 51.9%-95.7%), and 72.73% (95% CI, 51.91%-95.67%), respectively. The DECT brain edema images provided a sensitivity, specificity, PPV, and NPV of 93.33% (95% CI, 68.05%-99.83%), 100% (95% CI, 71.51%-100%), 100% (95% CI, 76.84%-100%), and 91.67% (95% CI, 61.52%-99.79%), respectively. There was very good interrater reliability across all 3 imaging techniques.

CONCLUSION

Brain edema reconstructions are able to more accurately detect edema and end-infarct volume as compared with initial TNC images. This provides a better assessment of the degree and extent of infarction and may serve to better guide therapy in the future.

Multi-phase 3D arterial spin labeling brain MRI in assessing cerebral blood perfusion and arterial transit times in children at 3T

BACKGROUND

3D pseudocontinuous arterial spin labeling (pCASL) with a single post-labeling delay time is commonly used to measure cerebral blood flow (CBF). Multi-phase pCASL has been developed to simultaneously estimate CBF and arterial transit time (ATT).

PURPOSE

To evaluate the clinical feasibility of multi-phase 3D pCASL in pediatric patients, and to compare the estimation of ATT and CBF via linear weighted-delay and traditional non-linear iterative curve-fitting routines.

MATERIAL & METHODS

Forty patients (average age: 8.6 y, 5 d-22.4 y) referred for routine brain MRI underwent additional 5-7 min of pCASL scans at 3T using 5 PLDs between 300 and 2300 ms. Data were post-processed by two algorithms for estimating CBF and ATT. Average CBF and ATT values were computed for vascular territories including the anterior, middle and posterior cerebral arteries as well as regions based on the Alberta Stroke Program Early CT Score template. Pearson correlation coefficients and linear regression were used for statistical analysis. The clinical value of multi-phase CASL was evaluated by a neuroradiologist based on asymmetric CBF and ATT maps in patients.

RESULTS

All pCASL scans were successfully completed, generating diagnostic results. CBF computed from weighted-delay and curve-fitting methods agreed strongly, with Pearson correlation coefficients ranging from 0.97-0.99 across the measured regions (p < 0.05). Correlation coefficients for ATT ranged from 0.87-0.96 (p < 0.05). CBF and ATT maps were found to add valuable information to clinical diagnosis in 17 of 40 pediatric patients.

CONCLUSION

Our preliminary results demonstrate the feasibility and potential clinical utility of multi-phase pCASL for simultaneous CBF and ATT quantification in pediatric patients.

Diagnosis and Treatment of Primary Central Nervous System Angiitis

PURPOSE OF REVIEW

Primary central nervous system angiitis (PCNSA) is a rare disease. Varying clinical pictures coupled with lack of sensitive and specific diagnostic tests lead to challenges in management of these patients. This unfortunately may lead to both under- or over-diagnosis and unnecessary treatment. It is important to recognize the different conditions that may mimic the clinical and radiologic presentation. We present a contemporary literature review that should update physicians who encounter this patient population.

RECENT FINDINGS

Recent additions to the literature in form of case reports and single-center series show that digital subtraction angiography was the most widely used test to diagnose PCNSA. It is also important to note that brain biopsy is still considered "gold standard" and should be pursued as it not only has information that establishes the diagnosis but also may help in ruling out the diagnosis from mimics. In around 39% of suspected cases, an alternate diagnosis was eventually confirmed highlighting the importance of a comprehensive work-up. For treatment, almost all the literature supports the use of glucocorticoids as the initial treatment and if the patient has a relapse or develops steroid toxicity then the second most commonly used agent was cyclophosphamide. There are increasing reports of benefits with other agents such as methotrexate, azathioprine, mycophenolate, infliximab, and etanercept. The diagnosis and management of PCNSA continues to be a challenge. Formation of prospective patient registries with continued immunologic research for novel targets and immunomodulatory modalities may hold promise for future care of these patients.

Computed Tomographic Perfusion Predicts Poor Outcomes in a Randomized Trial of Endovascular Therapy

Background and Purpose—

In the ESCAPE trial (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion with Emphasis on Minimizing CT to Recanalization Times), patients with large vessel occlusions and small infarct cores identified with computed tomography (CT)/CT angiography were randomized to endovascular therapy or standard of care. CT perfusion (CTP) was obtained in some cases but was not used to select patients. We tested the hypothesis that patients with penumbral CTP patterns have higher rates of good clinical outcome.

Methods—

All CTP data acquired in ESCAPE patients were analyzed centrally using a semiautomated perfusion threshold-based approach. A penumbral pattern was defined as an infarct core <70 mL, penumbral volume >15 mL, and a total hypoperfused volume:core volume ratio of >1.8. The primary outcome was good functional outcome at 90 days (modified Rankin Scale score, 0–2).

Results—

CTP was acquired in 138 of 316 ESCAPE patients. Penumbral patterns were present in 116 of 128 (90.6%) of patients with interpretable CTP data. The rate of good functional outcome in penumbral pattern patients (53 of 114; 46%) was higher than that in nonpenumbral patients (2 of 12; 17%; P =0.041). In penumbral patients, endovascular therapy increased the likelihood of a good clinical outcome (34 of 58; 57%) compared with those in the control group (19 of 58; 33%; odds ratio, 2.68; 95% confidence interval, 1.25–5.76; P =0.011). Only 3 of 12 nonpenumbral patients were randomized to the endovascular group, preventing an analysis of treatment effect.

Conclusions—

The majority of patients with CTP imaging in the ESCAPE trial had penumbral patterns, which were associated with better outcomes overall. Patients with penumbra treated with endovascular therapy had the greatest odds of good functional outcome. Nonpenumbral patients were much less likely to achieve good outcomes.