Reducing False-Positives in CT Perfusion Infarct Core Segmentation Using Contralateral Local Normalization

BACKGROUND AND PURPOSE

The established global threshold of rCBF <30% for infarct core segmentation can lead to false-positives, as it does not account for the differences in blood flow between GM and WM and patient-individual factors, such as microangiopathy. To mitigate this problem, we suggest normalizing each voxel not only with a global reference value (ie, the median value of normally perfused tissue) but also with its local contralateral counterpart.

MATERIALS AND METHODS

We retrospectively enrolled 2830 CTP scans with suspected ischemic stroke, of which 335 showed obvious signs of microangiopathy. In addition to the conventional, global normalization, a local normalization was performed by dividing the rCBF maps with their mirrored and smoothed counterpart, which sets each voxel value in relation to the contralateral counterpart, intrinsically accounting for GM and WM differences and symmetric patient individual microangiopathy. Maps were visually assessed and core volumes were calculated for both methods.

RESULTS

Cases with obvious microangiopathy showed a strong reduction in false-positives by using local normalization (mean 14.7 mL versus mean 3.7 mL in cases with and without microangiopathy). On average, core volumes were slightly smaller, indicating an improved segmentation that was more robust against naturally low blood flow values in the deep WM.

CONCLUSIONS

The proposed method of local normalization can reduce overestimation of the infarct core, especially in the deep WM and in cases with obvious microangiopathy. False-positives in CTP infarct core segmentation might lead to less-than-optimal therapy decisions when not correctly interpreted. The proposed method might help mitigate this problem.

Validation of a German-language modified Rankin Scale structured telephone interview at 3 months in a real-life stroke cohort

BACKGROUND

The modified Rankin scale (mRS) at 3 months is established as the primary outcome measure in clinical stroke trials. Traditionally, the mRS is assessed through an unstructured face-to-face interview. This approach can be labor-intensive and lead to suboptimal inter-rater reliability. Recently, the Covid-19 pandemic made face-to-face contact even more challenging. To address these issues, we developed and validated a structured German-language questionnaire for mRS testing by telephone.

METHODS

In this prospective cohort study, we compared the mRS testing results of the standard face-to-face interview with those obtained in a structured interview by telephone using Cohen's Kappa.

RESULTS

At our tertiary care stroke center, we included 108 patients who underwent both assessments. In 80.6% of cases (87/108) face-to-face and telephone interview reached identical scores. Linear weighted Kappa was 0.82 (p < 0.001). Unweighted Kappa for dichotomized mRS between fair (0-2) and poor (3-6) functional outcome was κ = 0.97 (p < 0.001).

CONCLUSIONS

Our study validates the use of the German-language structured telephone interview as a reliable instrument for the use in clinical trials. We encourage others to utilize the questionnaire. It is available as an Appendix (Additional file 1) to this publication.

Frequency and Characteristics of Non-Neurological and Neurological Stroke Mimics in the Emergency Department

BACKGROUND

Stroke mimics are common in the emergency department (ED) and early detection is important to initiate appropriate treatment and withhold unnecessary procedures. We aimed to compare the frequency, clinical characteristics and predictors of non-neurological and neurological stroke mimics transferred to our ED for suspected stroke.

METHODS

This was a cross-sectional study of consecutive patients with suspected stroke transported to the ED of the University Hospital Essen between January 2017 and December 2021 by the city's Emergency Medical Service. We investigated patient characteristics, preclinical data, symptoms and final diagnoses in patients with non-neurological and neurological stroke mimics. Multinominal logistic regression analysis was performed to assess predictors of both etiologic groups.

RESULTS

Of 2167 patients with suspected stroke, 762 (35.2%) were diagnosed with a stroke mimic. Etiology was non-neurological in 369 (48.4%) and neurological in 393 (51.6%) cases. The most common diagnoses were seizures (23.2%) and infections (14.7%). Patients with non-neurological mimics were older (78.0 vs. 72.0 y, p < 0.001) and more likely to have chronic kidney disease (17.3% vs. 9.2%, p < 0.001) or heart failure (12.5% vs. 7.1%, p = 0.014). Prevalence of malignancy (8.7% vs. 13.7%, p = 0.031) and focal symptoms (38.8 vs. 57.3%, p < 0.001) was lower in this group. More than two-fifths required hospitalization (39.3 vs. 47.1%, p = 0.034). Adjusted multinominal logistic regression revealed chronic kidney and liver disease as independent positive predictors of stroke mimics regardless of etiology, while atrial fibrillation and hypertension were negative predictors in both groups. Prehospital vital signs were independently associated with non-neurological stroke mimics only, while age was exclusively associated with neurological mimics.

CONCLUSIONS

Up to half of stroke mimics in the neurological ED are of non-neurological origin. Preclinical identification is challenging and a high proportion requires hospitalization. Awareness of underlying etiologies and differences in clinical characteristics is important to provide optimal care.

Treatment of acute ischemic stroke in patients with active malignancy: insight from a comprehensive stroke center

Background

Despite the high incidence of acute ischemic stroke (AIS) in cancer patients, there is still no consensus about the safety of recanalization therapies in this cohort.

Objectives

In this observational study, our aim was to investigate the bleeding risk after acute recanalization therapy in AIS patients with active malignancy.

Methods and Study Design

We retrospectively analyzed observational data of 1016 AIS patients who received intravenous thrombolysis with rtPA (IVT) and/or endovascular therapy (EVT) between January 2017 and December 2020 with a focus on patients with active malignancy. The primary safety endpoint was the occurrence of stroke treatment-related major bleeding events, that is, symptomatic intracranial hemorrhage (SICH) and/or relevant systemic bleeding. The primary efficacy endpoint was neurological improvement during hospital stay (NI).

Results

None of the 79 AIS patients with active malignancy suffered from stroke treatment-related systemic bleeding. The increased rate (7.6% versus 4.7%) of SICH after therapy compared to the control group was explained by confounding factors. A total of nine patients with cerebral tumor manifestation received acute stroke therapy, two of them suffered from stroke treatment-related intracranial hemorrhage remote from the tumor, both asymptomatic. The group of patients with active malignancy and the control group showed comparable rates of NI.

Conclusion

Recanalization therapy in AIS patients with active malignancy was not associated with a higher risk for stroke treatment-related systemic or intracranial bleeding. IVT and/or EVT can be regarded as a safe therapy option for AIS patients with active malignancy.

Thromboinflammatory challenges in stroke pathophysiology

Despite years of encouraging translational research, ischemic stroke still remains as one of the highest unmet medical needs nowadays, causing a tremendous burden to health care systems worldwide. Following an ischemic insult, a complex signaling pathway emerges leading to highly interconnected thrombotic as well as neuroinflammatory signatures, the so-called thromboinflammatory cascade. Here, we thoroughly review the cell-specific and time-dependent role of different immune cell types, i.e., neutrophils, macrophages, T and B cells, as key thromboinflammatory mediators modulating the neuroinflammatory response upon stroke. Similarly, the relevance of platelets and their tight crosstalk with a variety of immune cells highlights the relevance of this cell-cell interaction during microvascular dysfunction, neovascularization, and cellular adhesion. Ultimately, we provide an up-to-date overview of therapeutic approaches mechanistically targeting thromboinflammation currently under clinical translation, especially focusing on phase I to III clinical trials.

Circadian rhythm and aneurysmal subarachnoid hemorrhage: Is there an alarm clock for the rupture timing?

PURPOSE AND BACKGROUND

Data on the temporal distribution of the bleeding time of intracranial aneurysms is limited to few small studies. With this study, we aimed to analyze time patterns of the occurrence of aneurysmal subarachnoid hemorrhage (SAH), particularly focusing on the impact of patients' socio-demographic and clinical characteristics on the ictus timing.

METHODS

This study is based on the institutional SAH cohort with 782 consecutive cases treated between January 2003 and June 2016. Data was collected on the ictus time, patients' socio-demographic and clinical characteristics, as well as the initial severity and outcome. Univariate and multivariate analyses were performed on the bleeding timeline.

RESULTS

There were two peaks in the circadian rhythm of SAH, one in the morning (7 to 9 a.m.) and the other in the evening (7 to 9 p.m.). The strongest alterations in the bleeding time patterns were observed for weekdays, patients' age, sex, and ethnicity. Individuals with chronic alcohol and painkiller consumption showed a higher bleeding peak between 1 and 3 p.m. Finally, the bleeding time showed no impact on the severity, clinically relevant complications and the outcome of SAH patients.

CONCLUSIONS

This study is one of the very few detailed analyses of the impact of specific socio-demographic, ethnic, behavioral and clinical characteristics on the rupture timing of aneurysms. Our results point to the possible relevance of the circadian rhythm for the rupture event, and therefore might be useful in the elaboration of preventive measures against aneurysm rupture.

Management of carotid cavernous fistulas: A single center experience

Purpose

Multimodal endovascular therapy (EVT) of carotid cavernous fistula (CCF) with different approaches and a variety of available embolization material enable high occlusion rates with good clinical and functional outcome but until now there is still little evidence available. This retrospective single-center study aims to evaluate EVT of CCF with different neuroendovascular techniques regarding occlusion rates, complications and outcomes.

Materials and methods

From 2001 to 2021 59 patients with CCF were treated at our tertiary university hospital. Patient records and all imaging data including angiograms were reviewed for demographic and epidemiological data, symptoms, fistula type, number of EVTs, complications of EVT, type of embolic materials, occlusion rates and recurrences.

Results

Etiology of the CCF were spontaneous (41/59, 69.5%) post-traumatic (13/59, 22%) and ruptured cavernous aneurysms (5/59, 8.5%). Endovascular therapy was completed in one session in 74.6% (44/59). Transvenous access was most frequent (55.9% 33/59) followed by transarterial catheterization in 33.9% (20/59) and a combination of both (6/59, 10.2%). Exclusively coils were used in 45.8% (27/59), a combination of ethylene vinyl alcohol (EVOH) copolymer (Onyx) and coils in 42.4% (25/59). Complete obliteration was achieved in 96.6% of patients (57/59) with an intraprocedural-related complication rate of 5.1% (3/59) and no mortality.

Conclusion

Endovascular therapy of CCF has been shown to be safe and effective with high cure rates and low rates of intraprocedural complications and morbidity even in complex scenarios.

Small intracranial aneurysms of the anterior circulation: A negligible risk?

BACKGROUND AND PURPOSE

According to the International Study of Unruptured Intracranial Aneurysms, small (<7 mm) unruptured intracranial aneurysms (IAs) of the anterior circulation (aC) carry a neglectable 5-year rupture risk. In contrast, some studies report frequencies of >20% of all ruptured IAs being small IAs of the aC. This contradiction was addressed in this study by analyzing the rates and risk factors for rupture of small IAs within the aC.

METHODS

Of the institutional observational cohort, 1676 small IAs of the aC were included. Different demographic, clinical, laboratory, and radiographic characteristics were collected. A rupture risk score was established using all independent prognostic factors. The score performance was checked using receiver operating characteristic curve analysis.

RESULTS

Of all registered small IAs of the aC, 20.1% were ruptured. The developed small IAs of the aC (SIAAC) score (range = -4 to +13 points) contained five major risk factors: IA location and size, arterial hypertension, alcohol abuse, and chronic renal failure. In addition, three putative protective factors were also included in the score: hypothyroidism, dyslipidemia, and peripheral arterial disease. Increasing rates of ruptured IA with increasing SIAAC scores were observed, from 0% (≤-1 points) through >50% (≥8 points) and up to 100% in patients scoring ≥12 points. The SIAAC score achieved excellent discrimination (area under the curve_SIAAC  = 0.803) and performed better than the PHASES (Population,Hypertension, Age, Size of the aneurysm, Earlier SAH from another aneurysm, Site of aneurysm) score.

CONCLUSIONS

Small IAs of the aC carry a considerable rupture risk. After external validation, the proposed rupture risk score might provide a basis for better decision-making regarding the treatment of small unruptured IAs of the aC.

Multidisciplinary tumor board analysis: validation study of a central tool in tumor centers

The established standard to ensure state-of-the-art cancer treatment is through multidisciplinary tumor boards (TBs), although resource- and time-intensive. In this validation study, the multiple myeloma (MM)-TB was reexamined, aiming to validate our previous (2012-2014) results, now using the TB data from March 2020 to February 2021. We assessed MM-TB protocols, physicians' documentation, patient, disease, remission status, progression-free survival (PFS), and overall survival (OS) as left-truncated survival times. Moreover, TB-adherence, level of evidence according to grade criteria, time requirements, study inclusion rates, and referral satisfaction were determined. Within a 1-year period, 312 discussed patients were documented in 439 TB protocols. Patient and disease characteristics were typical for comprehensive cancer centers. The percentages of patients discussed at initial diagnosis (ID), with disease recurrence or in need of interdisciplinary advice, were 39%, 28%, and 33%, respectively. Reasons for the MM-TB presentation were therapeutic challenges in 80% or staging/ID-defining questions in 20%. The numbers of presentations were mostly one in 73%, two in 20%, and three or more in 7%. The TB adherence rate was 93%. Reasons for non-adherence were related to patients' decisions or challenging inclusion criteria for clinical trials. Additionally, we demonstrate that with the initiation of TBs, that the number of interdisciplinarily discussed patients increased, that TB-questions involve advice on the best treatment, and that levels of compliance and evidence can be as high as ≥ 90%. Advantages of TBs are that they may also improve patients', referrers', and physicians' satisfaction, inclusion into clinical trials, and advance interdisciplinary projects, thereby encouraging cancer specialists to engage in them.

Predictors of Symptomatic Intracranial Hemorrhage after Endovascular Thrombectomy in Acute Ischemic Stroke Patients with Anterior Large Vessel Occlusion-Procedure Time and Reperfusion Quality Determine

PURPOSE

We aimed to evaluate predictors of symptomatic intracranial hemorrhage (sICH) in acute ischemic stroke (AIS) patients following thrombectomy due to anterior large vessel occlusion (LVO).

METHODS

Data on stroke patients from January 2018 to December 2020 in a tertiary care centre were retrospectively analysed. sICH was defined as intracranial hemorrhage associated with a deterioration of at least four points in the National Institutes of Health Stroke Scale (NIHSS) score or hemorrhage leading to death. A smoothed ridge regression model was run to analyse the impact of 15 variables on their association with sICH.

RESULTS

Of the 174 patients (median age 77, 41.4% male), sICH was present in 18 patients. Short procedure time from groin puncture to reperfusion (per 10 min OR 1.24; 95% CI 1.071-1.435; p = 0.004) and complete reperfusion (TICI 3) (OR 0.035; 95% CI 0.003-0.378; p = 0.005) were significantly associated with a lower risk of sICH. On the contrary, successful reperfusion (TICI 3 and TICI 2b) was not associated with a lower risk of sICH (OR 0.508; 95% CI 0.131-1.975, p = 0.325). Neither the total time from symptom onset to reperfusion nor the intravenous thrombolysis was a predictor of sICH (per 10 min OR 1.0; 95% CI 0.998-1.001, p = 0.745) (OR 1.305; 95% CI 0.338-5.041, p = 0.697).

CONCLUSION

Our findings addressed the paramount importance of short procedure time and complete reperfusion to minimize sICH risk. The total ischemic time from onset to reperfusion was not a predictor of sICH.

CT and DSA for evaluation of spontaneous intracerebral lobar bleedings

Purpose

This study retrospectively examined the extent to which computed tomography angiography (CTA) and digital subtraction angiography (DSA) can help identify the cause of lobar intracerebral bleeding.

Materials and methods

In the period from 2002 to 2020, data from patients who were >18 years at a university and an academic teaching hospital with lobar intracerebral bleeding were evaluated retrospectively. The CTA DSA data were reviewed separately by two neuroradiologists, and differences in opinion were resolved by consensus after discussion. A positive finding was defined as an underlying vascular etiology of lobar bleeding.

Results

The data of 412 patients were retrospectively investigated. DSA detected a macrovascular cause of bleeding in 125/412 patients (33%). In total, sixty patients had AVMs (15%), 30 patients with aneurysms (7%), 12 patients with vasculitis (3%), and 23 patients with dural fistulas (6%). The sensitivity, specificity, positive and negative predictive values, and accuracy of CTA compared with DSA were 93, 97, 100, and 97%. There were false-negative CTA readings for two AVMs and one dural fistula.

Conclusion

The DSA is still the gold standard diagnostic modality for detecting macrovascular causes of ICH; however, most patients with lobar ICH can be investigated first with CTA, and the cause of bleeding can be found. Our results showed higher sensitivity and specificity than those of other CTA studies.

Medication intake and hemorrhage risk in patients with familial cerebral cavernous malformations

OBJECTIVE

The objective of this study was to analyze the impact of medication intake on hemorrhage risk in patients with familial cerebral cavernous malformation (FCCM).

METHODS

The authors' institutional database was screened for patients with FCCM who had been admitted to their department between 2003 and 2020. Patients with a complete magnetic resonance imaging (MRI) data set, evidence of multiple CCMs, clinical baseline characteristics, and follow-up (FU) examination were included in the study. The authors assessed the influence of medication intake on first or recurrent intracerebral hemorrhage (ICH) using univariate and multivariate logistic regression adjusted for age and sex. The longitudinal cumulative 5-year risk of hemorrhage was calculated by applying Kaplan-Meier and Cox regression analyses adjusted for age and sex.

RESULTS

Two hundred five patients with FCCMs were included in the study. Multivariate Cox regression analysis revealed ICH as a predictor for recurrent hemorrhage during the 5-year FU. The authors also noted a tendency toward a decreased association with ICH during FU in patients on statin medication (HR 0.22, 95% CI 0.03-1.68, p = 0.143), although the relationship was not statistically significant. No bleeding events were observed in patients on antithrombotic therapy. Kaplan-Meier analysis and log-rank test showed a tendency toward a low risk of ICH during FU in patients on antithrombotic therapy (p = 0.085), as well as those on statin therapy (p = 0.193). The cumulative 5-year risk of bleeding was 22.82% (95% CI 17.33%-29.38%) for the entire cohort, 31.41% (95% CI 23.26%-40.83%) for patients with a history of ICH, 26.54% (95% CI 11.13%-49.7%) for individuals on beta-blocker medication, 6.25% (95% CI 0.33%-32.29%) for patients on statin medication, and 0% (95% CI 0%-30.13%) for patients on antithrombotic medication.

CONCLUSIONS

ICH at diagnosis was identified as a risk factor for recurrent hemorrhage. Although the relationships were not statistically significant, statin and antithrombotic medication tended to be associated with decreased bleeding events.

Extrahepatic portosystemic shunts as an unusual but treatable cause of hyperammonemic encephalopathy in a noncirrhotic patient - a case report

We report a case of hyperammonemic encephalopathy due to extrahepatic portosystemic shunts in a noncirrhotic patient. A 79-year-old woman suffered from episodic confusion, disorientation, dysphasia and fluctuating level of consciousness. Electroencephalography (EEG) showed encephalopathic changes and serum levels of ammonia were elevated. Further investigation revealed mesenterorenal and mesenterocaval shunts, which had possibly evolved after pancreatic surgery 5 years ago. After shunt obliteration, the symptoms completely resolved, ammonia levels dropped to the normal range and EEG findings normalized. Clinicians should be aware of this rare but treatable cause of encephalopathy in noncirrhotic patients.

MOG antibody–associated encephalomyelitis mimicking bacterial meningomyelitis following ChAdOx1 nCoV-19 vaccination: a case report

We report a case of anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated encephalomyelitis following vector-based vaccination against SARS-CoV-2 that mimicked bacterial meningomyelitis upon initial presentation. A 43-year-old woman who had received a first dose of ChAdOx1 nCoV-19 (Vaxzevria; Astra Zeneca, UK Limited) 9 days earlier presented with subacute sensorimotor paraparesis, urinary retention, headache, meningism, and fever. Clinical findings and cerebrospinal fluid (CSF) features were highly suggestive of bacterial infection; however, despite receiving broad anti-infective treatment alongside with high-dose glucocorticoids, symptoms deteriorated. Imaging findings and the detection of immunoglobulin G against MOG substantiated diagnosis of an anti-MOG associated disorder. Treatment with high-dose intravenous (IV) methylprednisolone and plasma exchange resulted in substantial clinical improvement, which sustained under monthly regimen of IV Tocilizumab at 3-month follow-up. Awareness of this post-vaccinal presentation of a rare autoimmune disorder is important to not miss potential treatment options.

Predictors of Early Neurological Improvement in Patients with Anterior Large Vessel Occlusion and Successful Reperfusion Following Endovascular Thrombectomy-Does CT Perfusion Imaging Matter?

PURPOSE

We aimed to investigate treatment effect of endovascular thrombectomy (EVT) on the change of National Institutes of Health Stroke Scale (NIHSS) scores in acute ischemic stroke (AIS) patients with anterior large vessel occlusion (LVO). Predictors of early neurological improvement (ENI) were assessed in those with successful reperfusion.

METHODS

Data on stroke patients from January 2018 to December 2020 were retrospectively analyzed. Anterior LVO was defined as occlusion of internal carotid artery and/or M1/M2 branch of middle cerebral artery. A reduction of at least 8 NIHSS points at 24 h after EVT or NIHSS score ≤ 1 at discharge was defined as ENI. In patients with successful reperfusion (TICI score of 2b/3) and available CT perfusion (CTP) imaging, 20 variables were tested in a smoothed ridge regression for their association with ENI.

RESULTS

One hundred seventy two out of 211 patients had successful perfusion with 54 patients achieving ENI. Impact of successful EVT on reducing NIHSS score grew continuously on a daily basis up to the date of discharge. 105 out of 172 patients were included in final regression model. Short time from onset to admission and from groin-puncture to reperfusion, young age, low prestroke disability, high baseline CTP ASPECTS and high follow-up non-contrast CT (NCCT) ASPECTS were significantly associated with ENI. Neither baseline NCCT ASPECTS nor the volume of penumbra or ischemic core measured on CTP were associated with ENI.

CONCLUSION

CTP ASPECTS might better predict ENI than non-contrast CT at baseline in patients with successful reperfusion following EVT.

Validation of a shortened FAST-ED algorithm for smartphone app guided stroke triage

Background and Purpose:

Large vessel occlusion (LVO) recognition scales were developed to identify patients with LVO-related acute ischemic stroke (AIS) on the scene of emergency. Thus, they may enable direct transport to a comprehensive stroke centre (CSC). In this study, we aim to validate a smartphone app-based stroke triage with a shortened form of the Field Assessment Stroke Triage for Emergency Destination (FAST-ED).

Methods:

This retrospective validation study included 2815 patients with confirmed acute stroke and suspected acute stroke but final diagnosis other than stroke (stroke mimics) who were admitted by emergency medical service (EMS) to the CSC of the Neurological University Hospital Essen, Germany. We analysed the predictive accuracy of a shortened digital app-based FAST-ED ( ‘FAST-ED App’) for LVO-related AIS and yield comparison to various other LVO recognition scales.

Results:

The shortened FAST-ED App had comparable test quality (Area under ROC = 0.887) to predict LVO-related AIS to the original FAST-ED (0.889) and RACE (0.883) and was superior to Cincinnati Prehospital Stroke Severity (CPSS), 3-Item Stroke Scale (3-ISS) and National Institute of Health Stroke Scale (NIHSS). A FAST-ED App ⩾ 4 revealed very good accuracy to detect LVO related AIS (sensitivity of 77% and a specificity 87%) with an area under the curve c-statistics of 0.89 (95% CI: 0.87–0.90). In a hypothetical triage model, the number needed to screen in order to avoid one secondary transportation in an urban setting would be five.

Conclusion:

This validation study of a shortened FAST-ED assessment for a smartphone-app guided stroke triage yields good quality to identify patients with LVO.

FAST-ED scale smartphone app-based prediction of large vessel occlusion in suspected stroke by emergency medical service

Background and Purpose:

Considering the highly time-dependent therapeutic effect of endovascular treatment in patients with large vessel occlusion–associated acute ischemic stroke, prehospital identification of large vessel occlusion and subsequent triage for direct transport to a comprehensive stroke center offers an intriguing option for optimizing patient pathways.

Methods:

This prospective in-field validation study included 200 patients with suspected acute ischemic stroke who were admitted by emergency medical service to a comprehensive stroke center. Ambulances were equipped with smartphones running an app-based Field Assessment Stroke Triage for Emergency Destination scale for transmission prior to admission. The primary measure was the predictive accuracy of the transmitted Field Assessment Stroke Triage for Emergency Destination for large vessel occlusion and the secondary measure the predictive accuracy for endovascular treatment.

Results:

A Field Assessment Stroke Triage for Emergency Destination ⩾4 revealed very good accuracy to detect large vessel occlusion–related acute ischemic stroke with a sensitivity of 82.4% (95% confidence interval = 65.5–93.2), specificity of 78.3% (95% confidence interval = 71.3–84.3), and an area under the curve c-statistics of 0.89 (95% confidence interval = 0.85–0.94). Field Assessment Stroke Triage for Emergency Destination ⩾4 correctly identified 84% of patients who received endovascular treatment [73.5% specificity (95% confidence interval = 66.4–79.8)] with an area under the curve c-statistics of 0.82 (95% confidence interval = 0.74–0.89). In a hypothetical triage model of an urban setting, one secondary transportation would be avoided with every fifth patient screened.

Conclusion:

A smartphone app-based stroke triage completed by emergency medical service personnel showed adequate quality for the Field Assessment Stroke Triage for Emergency Destination to identify large vessel occlusion–associated acute ischemic stroke. We demonstrate feasibility of the use of a medical messaging service in prehospital stroke care. Based on these first results, a randomized trial evaluating the clinical benefit of such a triage system in an urban setting is currently in preparation.

Clinical Trial Registration: https://clinicaltrials.gov Unique identifier: NCT04404504.

Stroke due to Left Atrial Appendage Thrombus after Pulmonary Vein Isolation despite Novel Oral Anticoagulant: A Case Report

In patients with atrial fibrillation, catheter ablation is suggested to reduce the mortality rate and is thus frequently performed. However, peri- and postprocedural thromboembolic complications as well as high recurrence rates of atrial fibrillation limit its advantages and require concomitant anticoagulation. With the advent of novel oral anticoagulants (NOACs), fixed dosing without routine laboratory monitoring became feasible. Nevertheless, several factors are associated with either an overdose or an insufficient drug activity of NOACs. We report on a patient with atrial fibrillation undergoing catheter ablation and cardioversion suffering from ischemic stroke despite being under oral anticoagulation. It turned out that the drug activity of the NOACs used was repeatedly insufficient in spite of regular intake and adequate dosing. In sum, drug activity controls should be taken into consideration in patients with thrombotic events despite oral anticoagulation with NOACs.

A-14 Propensity Scores in Neuropsychological Research: Four Aspects of Digital Clock Drawing Distinguish Individuals with Non-Dementia Idiopathic Parkinson’s Disease from Matched Controls

Objective

In situations in which randomized experiments are impossible or unethical, propensity score matching offers a method to reduce bias on causal effect estimates (Thoemmes & Kim, 2011). In this study, we examined differences on the digital clock drawing test (dCDT; Souillard-Mandar et al., 2016) between individuals with idiopathic non-dementia Parkinson’s disease (PD) and matched controls.

Method

This study involved a retrospective analysis of two federally funded investigations (NSF-13-543; R01-NS082386). The sample included 261 participants (110 PD, 151 non-PD). Participants were matched according to demographic covariates, as well as measures of mood, comorbidity, and premorbid functioning. The PD group and matched controls were compared using logistic regression in a Bayesian framework, with projection predictive variable selection implemented to obtain a parsimonious model (Piironen, Paasiniemi, & Vehtari, 2018). All effects were standardized.

Results

Of 261 participants, 212 were matched using nearest neighbor matching (Figure 1). The final, parsimonious model included four variables from the dCDT: total strokes (command condition), total time (command condition), and area (command and copy conditions). While all effects were retained, positive to strong evidence was found for dCDT total time (βMedian = 0.91, βSD = 0.25, 95% CI [0.44, 1.42], Bayes factor [BF] = 97.80) and dCDT area (copy condition; βMedian = −0.52, βSD = 0.19, 95% CI [−0.90, −0.17], BF = 4.78).

Conclusions

Propensity scores can be employed in causal comparative studies to match control participants and reduce bias from nuisance covariates. Four aspects of dCDT performance were optimal in distinguishing individuals with PD from matched controls.

Sphenopalatine Ganglion Stimulation to Augment Cerebral Blood Flow

Background and Purpose—

Many patients with acute ischemic stroke are not eligible for thrombolysis or mechanical reperfusion therapies due to contraindications, inaccessible vascular occlusions, late presentation, or large infarct core. Sphenopalatine ganglion (SPG) stimulation to enhance collateral flow and stabilize the blood-brain barrier offers an alternative, potentially more widely deliverable, therapy.

Methods—

In a randomized, sham-controlled, double-masked trial at 41 centers in 7 countries, patients with anterior circulation ischemic stroke not treated with reperfusion therapies within 24 hours of onset were randomly allocated to active SPG stimulation or sham control. The primary efficacy outcome was improvement beyond expectations on the modified Rankin Scale of global disability at 90 days (sliding dichotomy), assessed in the modified intention-to-treat population. The initial planned sample size was 660 patients, but the trial was stopped early when technical improvements in device placement occurred, so that analysis of accumulated experience could be conducted to inform a successor trial.

Results—

Among 303 enrolled patients, 253 received at least one active SPG or sham stimulation, constituting the modified intention-to-treat population (153 SPG stimulation and 100 sham control). Age was median 73 years (interquartile range, 64–79), 52.6% were female, deficit severity on the National Institutes of Health Stroke Scale was median 11 (interquartile range, 9–15), and time from last known well median 18.6 hours (interquartile range, 14.5–22.5). For the primary outcome, improved 3-month disability beyond expectations, rates in the SPG versus sham treatment groups were 49.7% versus 40.0%; odds ratio, 1.48 (95% CI, 0.89–2.47); P =0.13. A significant treatment interaction with stroke location (cortical versus noncortical) was noted, P =0.04. In the 87 patients with confirmed cortical involvement, rates of improvement beyond expectations were 50.0% versus 27.0%; odds ratio, 2.70 (95% CI, 1.08–6.73); P =0.03. Similar response patterns were observed for all prespecified secondary efficacy outcomes. No differences in mortality or serious adverse event safety end points were observed.

Conclusions—

SPG stimulation within 24 hours of onset is safe in acute ischemic stroke. SPG stimulation was not shown to statistically significantly improve 3-month disability above expectations, though favorable outcomes were nominally higher with SPG stimulation. Beneficial effects may distinctively be conferred in patients with confirmed cortical involvement. The results of this study need to be confirmed in a larger pivotal study.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03767192.

Relative health-related quality of life after treatment of unruptured intracranial aneurysms: long-term outcomes and influencing factors

Health-related quality of life (HRQOL) is an important clinical outcome parameter. Its analysis is particularly meaningful to patients with minor functional impairment. The main goal of this study was to assess long-term data of HRQOL and their variables for patients undergoing treatment for unruptured intracranial aneurysms (UIAs). Therefore, a cross-sectional study of HRQOL (SF-36 questionnaire) was conducted in patients treated for UIA using a telephone survey assessing numerous medical and sociodemographic variables. A total of 96 patients with a follow up longer than 36 months post-treatment were included. HRQOL results were compared with the German reference population. Uni- and multivariate analyses were performed to detect variables with an impact on outcome. After a mean follow up of 57.75 ± 13.56 months, patients with treated UIAs showed a significant decrease in the mental health domains ‘role emotional’ and ‘social functioning’ and the ‘mental health component score’ (MHCS) compared with the age- and sex-matched reference population. Overall, 47% of the patients showed a clinically and psychosocially relevant decrease compared with the mean MHCS of the reference population. Multivariate analysis suggests that mainly the treatment modality (coiling versus clipping) and additional remaining untreated UIAs negatively impacted mental HRQOL. In conclusion, the partly significant losses in HRQOL identify the necessity for less-wearing treatment strategies and a better prediction of risk of UIA rupture. Our results indicate that certain factors in the guidance and management of patients undergoing endovascular treatment may negatively affect their mental HRQOL. The relevance of additional UIAs remaining untreated on HRQOL is a new finding that should be considered in the counseling of patients with multiple UIAs.

Learning while multitasking: short and long-term benefits of brain stimulation

We employed a simulated production task that mimics the real-world skill acquisition required of operators working in control rooms of power plants to assess short and long-term effects of transcranial random noise stimulation (tRNS). tRNS has shown potential for enhancing learning and performance of cognitive skills. Forty subjects (24 female) learned how to execute the simulated production task during the training phase and were required to perform a secondary task during the skill acquisition phase while they received active (12 min) or sham tRNS on DLPFC. After 2 weeks they had to recall the task again without any stimulation. The results demonstrate that tRNS promoted better multitasking as reflected by better performance in a secondary task during and immediately after tRNS. However, 2 weeks later, beneficial effect of tRNS on retention was moderated by general mental ability. Particularly, tRNS benefited those with lower general mental ability. Practitioner summary: By using a simulated production task, we assessed the effects of tRNS on learning and skill retention. The study indicates that neurostimulation can enhance the learning of multiple complex tasks. Moreover, it shows that retention of those tasks can be supported by neurostimulation, especially for those with lower general mental ability.

Revealing the subfemtosecond dynamics of orbital angular momentum in nanoplasmonic vortices

The ability of light to carry and deliver orbital angular momentum (OAM) in the form of optical vortices has attracted much interest. The physical properties of light with a helical wavefront can be confined onto two-dimensional surfaces with subwavelength dimensions in the form of plasmonic vortices, opening avenues for thus far unknown light-matter interactions. Because of their extreme rotational velocity, the ultrafast dynamics of such vortices remained unexplored. Here we show the detailed spatiotemporal evolution of nanovortices using time-resolved two-photon photoemission electron microscopy. We observe both long- and short-range plasmonic vortices confined to deep subwavelength dimensions on the scale of 100 nanometers with nanometer spatial resolution and subfemtosecond time-step resolution. Finally, by measuring the angular velocity of the vortex, we directly extract the OAM magnitude of light.

Wilm’s tumor: Presentation and outcome at Kilimanjaro Christian Medical Center

Objective: The purpose of the present study was to identify the gaps in the management of Wilms’ tumor which resulted in an inferior outcome and to see if there is any improvement since the last study and to come up with recommendations to improve the outcome of Wilms’ tumor. Patients and Methods: This was a retrospective hospital based study at Urology Institute of Kilimanjaro Christian Medical Centre. Patients operated for Wilms’ tumor between January 2006 and December 2013 were identified and the medical records of the 46 patients eligible for the study retrieved. The relevant information was entered into the prepared data collection format. The data was cleaned, summarized and analysed using SPSS version 17. Results: Patients with Wilms’ tumor presented late to KCMC. There was no undue delay in reaching at diagnosis. From the 46 total number of patients in this study 20 (43.5%) of patients received neoadjuvant chemotherapy while 26 (56.5%) had an upfront nephrectomy. The one year recurrence free survival was 32.6% with a high rate of lost to follow up (41.3%), perioperative mortality of (10.8%), and recurrence rate of (26.8%). Conclusion: There was no improvement in the outcome of WT at KCMC compared to the last report 8 years back. Patients still present late to health institutions, there is high rate of lost to follow up and the prognosis of Wilm’s tumor in this part of Africa is still dismal.

Associations of chronic heart failure with outcome in acute ischaemic stroke patients who received systemic thrombolysis: analysis from VISTA

BACKGROUND AND PURPOSE

There are concerns that systemic thrombolysis might not achieve clinically important outcome amongst chronic heart failure (CHF) patients with acute ischaemic stroke. Our aim was to investigate the relevance of CHF on the outcome of acute stroke patients who received thrombolysis.

METHODS

A non-randomized cohort analysis was conducted using data obtained from the Virtual International Stroke Trials Archive. The association of outcome amongst CHF patients with thrombolysis treatment was described using the modified Rankin scale (mRS) distribution at day 90, stratified by the presence of atrial fibrillation. Dichotomized outcomes were considered as a secondary end-point.

RESULTS

5677 patients were identified, of whom 2366 (41.7%) received thombolysis. Five hundred and three (8.9%) patients had CHF, of whom 209 (41.6%) received thrombolysis. The presence of CHF was associated with a negative impact on overall stroke outcome [odds ratio (OR) 0.73 (95% confidence interval (CI) 0.62-0.87), P < 0.001]. However, thrombolysis treatment was associated with favourable functional outcome using ordinal mRS, irrespective of CHF status, after adjustment for age and baseline National Institutes of Health Stroke Scale [OR 1.44 (95% CI 1.04-2.01, P = 0.029) for CHF patients versus OR 1.50 (95% CI 1.36-1.66, P < 0.001) for non-CHF patients]. CHF patients had higher mortality at day 90 than non-CHF patients. There was no significant difference for recurrent stroke or symptomatic intracerebral haemorrhage within 7 days of the initial stroke between CHF and thrombolysis groups.

CONCLUSIONS

Chronic heart failure was associated with a worse outcome with or without thrombolysis. However, acute stroke patients who received thrombolysis had more favourable outcome regardless of CHF status, compared with their untreated peers. Our findings should reassure clinicians considering systemic thrombolysis treatment in hyperacute ischaemic stroke patients with CHF.

[New aspects of stroke medicine]

Systemic thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) remains the only effective and approved medical treatment of acute ischemic stroke. Several studies have demonstrated the importance of rapid recanalization. The efficacy of thrombectomy has so far not been sufficiently shown in randomized clinical trials; therefore, inclusion of suitable patients in one of the currently ongoing randomized trials is of great importance. The early treatment with magnesium after acute ischemic stroke during the pre-hospital phase did not prove to be neuroprotective. Intermittent pneumatic compression of the lower extremities in immobilized stroke patients effectively prevents deep venous thrombosis and pulmonary embolism. In patients with lacunar stroke the combination of aspirin and clopidogrel is not superior to aspirin alone and causes more bleeding complications. The novel oral anticoagulants are superior to warfarin in secondary prevention and carry a lower risk of intracranial and systemic bleeding complications. New studies will investigate whether dabigatran or rivaroxaban are superior to aspirin in secondary prevention after cryptogenic stroke.

The effect of time to treatment on outcome in very elderly thrombolysed stroke patients

BACKGROUND

Intravenous thrombolysis is beneficial in, even very elderly, acute ischemic stroke patients. However, while the relation between treatment benefit and treatment delay (onset time to treatment) in patients younger than 80 years is well known, it is uncertain in the very elderly.

AIMS

This analysis aims at examining this relationship in the elderly, and to provide a comparison with the derived relationship in younger patients as a check of validity.

METHODS

We assessed the interaction between age, onset time to treatment, and thrombolysis exposure by analyzing the modified Rankin scale score distribution or mortality rate at 90 days, among patients registered in a trials archive. We established whether the effect of alteplase changes with onset time to treatment, by treating onset time to treatment as a continuum in a multivariate logistic regression model.

RESULTS

Data were available for 3063 patients, of whom 2341 were thrombolysed. Five hundred ninety-seven patients were aged >80, of whom 352 were thrombolysed. Among patients aged >80, no significant interaction of outcome with onset time to treatment was observed (P = 0·4650), but the estimated slope of the decay in benefit with onset time to treatment was comparable with that established for younger patients. Analyzing the entire dataset, there was an interaction between onset time to treatment and alteplase treatment (P = 0·0159), but neither between age and onset time to treatment (P = 0·7098) nor between age and alteplase treatment (P = 0·0755).

CONCLUSIONS

In this nonrandomized comparison, the relationship of benefit and safety with thrombolysis across onset time to treatment in very elderly stroke patients was comparable with that in their younger counterparts. Across the investigated time span of 3·5 h, we can safely treat with the same time window as we use for younger patients.

Interdependence of stroke outcome scales: reliable estimates from the Virtual International Stroke Trials Archive (VISTA)

BACKGROUND AND PURPOSE

Clinical deficits from stroke are diverse, prompting measurement in trials by a range of outcome scales. Statistical and clinical advantage can be gained by combining scales into a global outcome provided combinations are chosen with limited correlations. We aimed to clarify the interdependence of outcome scales by systematic review of published data and by novel analysis of data from completed acute trials.

SUMMARY OF REVIEW

We systematically searched ScienceDirect and PubMed to summarize published data on correlations between stroke outcome scales. We generated new data on correlations among salient scales at 90 days poststroke in patients from the Virtual International Stroke Trials Archive (VISTA). We calculated Pearson and Spearman-Rank correlation coefficients for continuous and ordinal measures, respectively. We also assessed partial correlations, adjusted for baseline National Institute of Health Stroke Scale (NIHSS), and age. Published estimates of interdependence were limited to small single-trial cohorts and gave divergent results. From the more extensive VISTA dataset, we found that the modified Rankin Scale at 90 days poststroke explained 80.8% of the National Institute of Health Stroke Scale at 90 days poststroke and 86.5% of the European Stroke Scale. National Institute of Health Stroke Scale explained 75.9% of the Barthel Index and 81.2% of the Scandinavian Stroke Scale. After adjustment, modified Rankin Scale explained 56.6% of National Institute of Health Stroke Scale, 75.2% of Barthel Index. National Institute of Health Stroke Scale explained 60.2% of Barthel Index.

CONCLUSION

Correlations and partial correlations among stroke outcome scales in trial datasets are higher than previously reported. The new estimates are more reliable for trial planning due to the sample size and diversity.

Impact of benzodiazepines on functional outcome and occurrence of pneumonia in stroke: evidence from VISTA

BACKGROUND

Benzodiazepines have been proposed both as a neuroprotectant and risk factor for pneumonia in acute stroke.

AIMS

We assessed the impact of benzodiazepine exposure on the modified Rankin scale score distribution at 90 days as well as pneumonia rates among patients registered in a trials archive.

METHOD

We used an age, baseline National Institutes of Health Stroke Score, and thrombolysis-rate adjusted Cochran-Mantel-Haenszel test to test significance (P) followed by proportional odds logistic regression analysis to estimate the odds ratios for improved modified Rankin scale score, and binary logistic regression to estimate the odds ratio for developing pneumonia.

RESULTS

Data were available for 5938 patients, of whom 1800 received benzodiazepines. No association of benzodiazepine use and overall stroke outcome could be found (odds ratio 0·90, 95% confidence interval 0·82-1·00, P=0·121). Pneumonia occurred in 12·8% of patients treated with benzodiazepines and in 13·6% of the controls (odds ratio 0·99, 95% confidence interval 0·83-1·18, P=0·904).

CONCLUSION

In this nonrandomized comparison, treatment with benzodiazepines as a concomitant medication had no independent impact on stroke outcome.

Intracluster correlation coefficients and reliability of randomized multicenter stroke trials within VISTA

BACKGROUND

Reliable estimates of intracluster correlation coefficients (ICCs) for specific outcome measures are crucial for sample size calculations of future cluster randomized trials. ICCs indicate the proportion of data variability that is explained by defined levels of clustering.

AIMS

In this manuscript, we present potentially valuable and reliable estimates of ICCs for specific baseline and follow-up data.

METHOD

ICCs were estimated from linear and generalized linear mixed models using maximum likelihood estimation for common measures used in stroke research, including modified Rankin Scale (mRS), National Institutes of Health Stroke Scale (NIHSS), and Barthel Index (BI).

RESULTS

Data were available for 11 841 patients with ischemic stroke from 11 randomized trials. After adjusting for age, thrombolysis, and baseline NIHSS, the median ICC for follow-up data, using center as the level of clustering, ranged from 0·007 to 0·041. The ICCs using trial, continent or year of enrollment as level of clustering were distinctly lower. Less than 1% of the variability of mRS, NIHSS, and BI was explained by any of these three cluster levels.

CONCLUSION

This compendium of relevant ICC estimates should assist trial planning. For example, the sample size for a cluster trial with 150 patients per center using ordinal analysis of mRS should be inflated by 2·0 due to the ICC of 0·007; whereas the ICC of 0·031 using mRS dichotomized above mRS 0-1, requires inflation by 5·6. The low contribution of trials, year or continent of enrollment to overall variation in outcome offers reassurance that analyses using pooled data from multiple trials in VISTA are unlikely to suffer from bias from these sources.

Use of paracetamol in ischaemic stroke patients: evidence from VISTA

OBJECTIVES

Paracetamol is frequently prescribed for pain and fever control in acute stroke patients, but its effect on stroke outcome is unclear. The aim was to investigate the safety and benefit of paracetamol administration in the acute phase of ischaemic stroke.

METHODS

We analysed the impact of paracetamol exposure on functional outcome at 90 days among ischaemic stroke patients registered in a clinical trials archive. We used an adjusted Cochran-Mantel-Haenszel test to test for significance (P) followed by proportional odds logistic regression analysis to estimate the odds ratios (OR) for more favourable modified Rankin Scale score.

RESULTS

Data were available for 6015 patients, of whom 2435 had received paracetamol. No association of paracetamol-use with overall stroke outcome could be detected among those patients who experienced pain and/or fever (OR 1.03, 95% CI 0.86-1.20, P = 0.931). In patients without recorded pain and/or fever events and a baseline temperature below 37°C, in whom paracetamol was started within 3 days of stroke, paracetamol was associated with worse outcome (OR 0.58, 95% CI 0.47-0.72, P = <0.001).

CONCLUSION

This retrospective analysis is discouraging for prophylactic use of paracetamol in acute stroke patients, but underlines the need for a sufficiently powered randomized controlled trial.