Validation of a simple clinical tool for screening of acute lacunar stroke-A substudy of the WAKE-UP trial

INTRODUCTION

Lacunar stroke represents around a quarter of all ischemic strokes; however, their identification with computed tomography in the hyperacute setting is challenging. We aimed to validate a clinical score to identify lacunar stroke in the acute setting, independently, with data from the WAKE-UP trial using magnetic resonance imaging.

METHODS

We analyzed data from the WAKE-UP trial and extracted Oxfordshire Community Stroke Project (OCSP) classification. Lacunar score was defined by National Institutes of Health Stroke Scale (NIHSS) < 7 and OCSP lacunar syndrome. Assessment of lacunar infarct by two independent investigators was blinded to clinical data. We calculated sensitivity, specificity, negative and positive predictive value (NPV and PPV, respectively) of lacunar score.

RESULTS

We included 503 patients in the analysis, mean (±SD) age 65.2 (±11.6) years, 325 (65%) males, median (IQR) NIHSS = 6 (4-9); 108 (22%) lacunar infarcts were identified on magnetic resonance (MR), patients fulfilling lacunar score criteria were 120 (24%), of which 47 (44%) had a lacunar infarct. Lacunar score was negative in 322 (82%) of patients without lacunar infarct. Patients with lacunar score had lower NIHSS (4 vs 7, p < 0.001), higher systolic (157 vs 151 mmHg, p = 0.001) and diastolic (86 vs 83 mmHg, p = 0.013) blood pressure and smaller infarct volume (2.4 vs 9.5 mL, p < 0.001). Performance of lacunar score was as follows: sensitivity 0.44; specificity 0.82; PPV 0.39; NPV 0.84; and accuracy 0.73. Assuming a prevalence of lacunar stroke of 13%, PPV lowered to 0.30 but NPV was 0.90. Lacunar score performed better for supratentorial lacunar infarcts.

CONCLUSION

Lacunar score had a very good specificity and NPV for screening of lacunar stroke. Implementation of this simple tool into clinical practice may help hyperacute management and guide patient selection in clinical trials.

DATA ACCESS STATEMENT

Data supporting the results of this paper are available upon reasonable request to the corresponding author.

Intravenous Thrombolysis in Patients With White Matter Hyperintensities in the WAKE-UP Trial

BACKGROUND

White matter hyperintensities of presumed vascular origin (WMH) are the most prominent imaging feature of cerebral small vessel disease (cSVD). Previous studies suggest a link between cSVD burden and intracerebral hemorrhage and worse functional outcome after thrombolysis in acute ischemic stroke. We aimed to determine the impact of WMH burden on efficacy and safety of thrombolysis in the MRI-based randomized controlled WAKE-UP trial of intravenous alteplase in unknown onset stroke.

METHODS

The design of this post hoc study was an observational cohort design of a secondary analysis of a randomized trial. WMH volume was quantified on baseline fluid-attenuated inversion recovery images of patients randomized to either alteplase or placebo in the WAKE-UP trial. Excellent outcome was defined as score of 0-1 on the modified Rankin Scale after 90 days. Hemorrhagic transformation was assessed on follow-up imaging 24-36 hours after randomization. Treatment effect and safety were analyzed by fitting multivariable logistic regression models.

RESULTS

Quality of scans was sufficient in 441 of 503 randomized patients to delineate WMH. Median age was 68 years, 151 patients were female, and 222 patients were assigned to receive alteplase. Median WMH volume was 11.4 mL. Independent from treatment, WMH burden was statistically significantly associated with worse functional outcome (odds ratio, 0.72 [95% CI, 0.57-0.92]), but not with higher chances of any hemorrhagic transformation (odds ratio, 0.78 [95% CI, 0.60-1.01]). There was no interaction of WMH burden and treatment group for the likelihood of excellent outcome (P=0.443) or any hemorrhagic transformation (P=0.151). In a subgroup of 166 patients with severe WMH, intravenous thrombolysis was associated with higher odds of excellent outcome (odds ratio, 2.40 [95% CI, 1.19-4.84]) with no significant increase in the rate of hemorrhagic transformation (odds ratio, 1.96 [95% CI, 0.80-4.81]).

CONCLUSIONS

Although WMH burden is associated with worse functional outcome, there is no association with treatment effect or safety of intravenous thrombolysis in patients with ischemic stroke of unknown onset.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01525290.

Reversibility of Diffusion-Weighted Imaging Lesions in Patients With Ischemic Stroke in the WAKE-UP Trial

BACKGROUND

Reversibility of the diffusion-weighted imaging (DWI) lesion means that not all of the DWI lesion represents permanently injured tissue. We investigated DWI reversibility and the association with thrombolysis, reperfusion and functional outcome in patients from the WAKE-UP trial (Efficacy and Safety of Magnetic Resonance Imaging-Based Thrombolysis in Wake-Up Stroke).

METHODS

In this retrospective analysis of WAKE-UP, a randomized controlled trial (RCT) between September 2012 and June 2017 in Belgium, Denmark, France, Germany, Spain and United Kingdom, a convolutional neural network segmented the DWI lesions (b=1000 s/mm²) at baseline and follow-up (24 hours). We calculated absolute and relative DWI reversibility in 2 ways: first, a volumetric (baseline volume-24-hour volume >0) and second, a voxel-based (part of baseline lesion not overlapping with 24-hour lesion) approach. We additionally defined relative voxel-based DWI-reversibility >50% to account for coregistration inaccuracies. We calculated the odds ratio for reversibility according to treatment arm. We analyzed the association of reversibility with excellent functional outcome (modified Rankin Scale score of 0-1), in a multivariable model.

RESULTS

In 363 patients, the median DWI volume was 3 (1-10) mL at baseline and 6 (2-20) mL at follow-up. Volumetric DWI reversibility was present in 19% (69/363) with a median absolute reversible volume of 1 mL (0-2) or 28% (14-50) relatively. Voxel-based DWI reversibility was present in 358/363 (99%) with a median absolute volume of 1 mL (0-2), or 22% (9-38) relatively. In 18% of the patients (67/363), relative voxel-based DWI reversibility >50% was present. Volumetric DWI reversibility and relative voxel-based DWI reversibility >50% was more frequent in patients treated with alteplase versus placebo (OR, 1.86 [95% CI, 1.09-3.17] and OR, 2.03 [95% CI, 1.18-3.50], respectively). Relative voxel-based DWI reversibility >50% was associated with excellent functional outcome (OR, 2.30 [95% CI, 1.17-4.51]).

CONCLUSIONS

Small absolute volumes of DWI reversibility were present in a large proportion of randomized patients in the WAKE-UP trial. Reversibility was more often present after thrombolysis.

Plasma acylcarnitines and gut-derived aromatic amino acids as sex-specific hub metabolites of the human aging metabolome

Aging biology entails a cell/tissue deregulated metabolism that affects all levels of biological organization. Therefore, the application of "omic" techniques that are closer to phenotype, such as metabolomics, to the study of the aging process should be a turning point in the definition of cellular processes involved. The main objective of the present study was to describe the changes in plasma metabolome associated with biological aging and the role of sex in the metabolic regulation during aging. A high-throughput untargeted metabolomic analysis was applied in plasma samples to detect hub metabolites and biomarkers of aging incorporating a sex/gender perspective. A cohort of 1030 healthy human adults (45.9% females, and 54.1% males) from 50 to 98 years of age was used. Results were validated using two independent cohorts (1: n = 146, 53% females, 30-100 years old; 2: n = 68, 70% females, 19-107 years old). Metabolites related to lipid and aromatic amino acid (AAA) metabolisms arose as the main metabolic pathways affected by age, with a high influence of sex. Globally, we describe changes in bioenergetic pathways that point to a decrease in mitochondrial β-oxidation and an accumulation of unsaturated fatty acids and acylcarnitines that could be responsible for the increment of oxidative damage and inflammation characteristic of this physiological process. Furthermore, we describe for the first time the importance of gut-derived AAA catabolites in the aging process describing novel biomarkers that could contribute to better understand this physiological process but also age-related diseases.

Predictors of Early Neurological Improvement and Its Relationship to Thrombolysis Treatment and Long-Term Outcome in the WAKE-UP Study

INTRODUCTION

The aims of this study were to evaluate the relationship of clinical and imaging baseline factors and treatment on the occurrence of early neurological improvement (ENI) in the WAKE-UP trial of MRI-guided intravenous thrombolysis in unknown onset stroke and to examine the association of ENI with long-term favorable outcome in patients treated with intravenous thrombolysis.

METHODS

We analyzed data from all patients with at least moderate stroke severity, reflected by an initial National Institutes of Health Stroke Scale (NIHSS) score ≥4 randomized in the WAKE-UP trial. ENI was defined as a decrease in NIHSS of ≥8 or a decline to zero or 1 at 24 h after initial presentation to the hospital. Favorable outcome was defined as a modified Rankin Scale score of 0-1 at 90 days. We performed group comparison and multivariable analysis of baseline factors associated with ENI and performed mediation analysis to evaluate the effect of ENI on the relationship between intravenous thrombolysis and favorable outcome.

RESULTS

ENI occurred in 93 out of 384 patients (24.2%) and was more likely to occur in patients who received treatment with alteplase (62.4% vs. 46.0%, p = 0.009), had smaller acute diffusion-weighted imaging lesion volume (5.51 mL vs. 10.9 mL, p ≤ 0.001), and less often large-vessel occlusion on initial MRI (7/93 [12.1%] versus 40/291 [29.9%], p = 0.014). In multivariable analysis, treatment with alteplase (OR 1.97, 95% confidence interval [CI] 0.954-1.100), lower baseline stroke volume (OR 0.965, 95% CI: 0.932-0.994), and shorter time from symptom recognition to treatment (OR 0.994, 95% CI: 0.989-0.999) were independently associated with ENI. Patients with ENI had higher rates of favorable outcome at 90-day follow-up (80.6% vs. 31.3%, p ≤ 0.001). The occurrence of ENI significantly mediated the association of treatment with a good outcome, with ENI at 24 h explaining 39.4% (12.9-96%) of the treatment effect.

CONCLUSION

Intravenous alteplase increases the odds of ENI in patients with at least moderate stroke severity, especially when given early. In patients with large-vessel occlusion, ENI is rarely observed without thrombectomy. ENI represents a good surrogate early marker of treatment effect as more than a third of good outcome at 90 days is explained by ENI at 24 h.

Sex differences in imaging and clinical characteristics of patients from the WAKE-UP trial

BACKGROUND AND PURPOSE

Sex-based differences in acute ischemic stroke are a well-known phenomenon. We aimed to explore these differences between women and men in the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial.

METHODS

We compared baseline demographic and imaging characteristics (visual fluid-attenuated inversion recovery [FLAIR] positivity, relative FLAIR signal intensity, collateral status) between women and men in all screened patients. In randomized patients (i.e., those with diffusion-weighted imaging (DWI)-FLAIR mismatch), we evaluated a modifying role of sex on the treatment effect of alteplase in multivariable logistic regression, with treatment adjusted for National Institute of Health Stroke Scale (NIHSS) score and age. Dependent variables were modified Rankin Scale (mRS) score of 0-1 at 90 days and distribution of mRS scores at 90 days.

RESULTS

Of 1362 screened patients, 529 (38.8%) were women. Women were older than men, had higher baseline NIHSS scores and smoked less frequently. FLAIR positivity of the DWI lesion was equally present in women (174/529, 33.1%) and men (273/833, 33.3%; p = 1.00) and other imaging variables also did not differ between the sexes. In a total of 503 randomized patients, of whom 178 were women (35.4%), sex did not modify the treatment effect of alteplase on mRS score 0-1 or on the total distribution of mRS scores.

CONCLUSION

As in many other stroke trials, more men than women were included in the WAKE-UP trial, but the presence of a visual DWI-FLAIR mismatch and the relative FLAIR signal intensity did not differ between the sexes. The treatment effect of alteplase was not modified by sex.

Patient-Reported Quality of Life After Intravenous Alteplase for Stroke in the WAKE-UP Trial

BACKGROUND AND OBJECTIVES

Intravenous alteplase improves functional outcome after acute ischemic stroke. However, little is known about the effects on self-reported health-related quality of life (HRQoL).

METHODS

WAKE-UP was a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in stroke with unknown onset time. HRQoL was assessed using the EuroQol five-dimensional questionnaire (EQ-5D) at 90 days, comprising the EQ-5D index and the EQ visual analogue scale (VAS). Functional outcome was assessed by the modified Rankin Scale (mRS). We calculated the effect of treatment on EQ-5D index and EQ VAS using multiple linear regression models. Mediation analysis was performed on stroke survivors to explore the extent to which the effect of alteplase on HRQoL was mediated by functional outcome.

RESULTS

Among 490 stroke survivors, the EQ-5D index was available for 452 (92.2%), of whom 226 (50%) were assigned to treatment with alteplase and 226 (50%) to placebo. At 90 days, mean EQ-5D index was higher, reflecting a better health state, in patients randomized to treatment with alteplase than with placebo (0.75 vs 0.67) with an adjusted mean difference of 0.07 (95% CI 0.02-0.12, p = 0.005). In addition, mean EQ VAS was higher with alteplase than with placebo (72.6 vs 64.9), with an adjusted mean difference of 7.6 (95% CI 3.9-11.8, p < 0.001). Eighty-five percent of the total treatment effect of alteplase on the EQ-5D index was mediated using the mRS score while there was no significant direct effect. By contrast, the treatment effect on the EQ VAS was mainly through the direct pathway (60%), whereas 40% was mediated by the mRS.

DISCUSSION

Assessment of patient-reported outcome measures reveals a potential benefit of intravenous alteplase for HRQoL beyond improvement of functional outcome.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov number, NCT01525290; EudraCT number, 2011-005906-32.

The effect of external stimulation on functional networks in the aging healthy human brain

Understanding the brain changes occurring during aging can provide new insights for developing treatments that alleviate or reverse cognitive decline. Neurostimulation techniques have emerged as potential treatments for brain disorders and to improve cognitive functions. Nevertheless, given the ethical restrictions of neurostimulation approaches, in silico perturbation protocols based on causal whole-brain models are fundamental to gaining a mechanistic understanding of brain dynamics. Furthermore, this strategy could serve to identify neurophysiological biomarkers differentiating between age groups through an exhaustive exploration of the global effect of all possible local perturbations. Here, we used a resting-state fMRI dataset divided into middle-aged (N =310, <65 years) and older adults (N =310, $\geq $65) to characterize brain states in each group as a probabilistic metastable substate (PMS) space. We showed that the older group exhibited a reduced capability to access a metastable substate that overlaps with the rich club. Then, we fitted the PMS to a whole-brain model and applied in silico stimulations in each node to force transitions from the brain states of the older- to the middle-aged group. We found that the precuneus was the best stimulation target. Overall, these findings could have important implications for designing neurostimulation interventions for reversing the effects of aging on whole-brain dynamics.

Asynchronous online learning as a key tool to adapt to new educational needs in radiology during the COVID-19 pandemic

The risk of contagion and the lockdown caused by the COVID-19 pandemic forced a change in teaching methodologies in radiology. New knowledge about the disease that was being acquired on a daily basis needed to be rapidly spread worldwide, but the restrictions imposed made it difficult to share this information. This paper describes the methodology applied to design and launch a practice-based course on chest X-ray suggestive of COVID-19 right after the pandemic started, and aims to determine whether asynchronous online learning tools for radiology education are useful and acceptable to general practitioners and other medical personnel during a pandemic. The study was carried out from April to October 2020 and involved 2632 participants. Pre- and post-testing was used to assess the participants' gain of knowledge in the course content (paired t-tests and chi-squared tests of independence). A five-point Likert scale questionnaire inspired by the technological acceptance model (TAM) was provided to evaluate the e-learning methodology (ANOVA tests). The results from the pre- and post-tests showed that there were significant differences in the scores before and after completing the course (sample size = 2632, response rate = 56%, p<0.001). As for the questionnaire, all questions surpassed 4.5 out of 5, including those referring to perceived ease of use and perceived usefulness, and no significant differences were found between experienced and inexperienced participants (sample size = 2535, response rate = 53%, p=0.85). The analysis suggests that the applied methodology is flexible enough to adapt to complex situations, and is useful to improve knowledge on the subject of the course. Furthermore, a wide acceptance of the teaching methodology is confirmed for all technological profiles, pushing for and endorsing a more widespread use of online platforms in the domain of radiology continuing education.

Early effect of thrombolysis on structural brain network organisation after anterior‐circulation stroke in the randomized WAKE‐UP trial

The symptoms of acute ischemic stroke can be attributed to disruption of the brain network architecture. Systemic thrombolysis is an effective treatment that preserves structural connectivity in the first days after the event. Its effect on the evolution of global network organisation is, however, not well understood. We present a secondary analysis of 269 patients from the randomized WAKE‐UP trial, comparing 127 imaging‐selected patients treated with alteplase with 142 controls who received placebo. We used indirect network mapping to quantify the impact of ischemic lesions on structural brain network organisation in terms of both global parameters of segregation and integration, and local disruption of individual connections. Network damage was estimated before randomization and again 22 to 36 h after administration of either alteplase or placebo. Evolution of structural network organisation was characterised by a loss in integration and gain in segregation, and this trajectory was attenuated by the administration of alteplase. Preserved brain network organization was associated with excellent functional outcome. Furthermore, the protective effect of alteplase was spatio‐topologically nonuniform, concentrating on a subnetwork of high centrality supported in the salvageable white matter surrounding the ischemic cores. This interplay between the location of the lesion, the pathophysiology of the ischemic penumbra, and the spatial embedding of the brain network explains the observed potential of thrombolysis to attenuate topological network damage early after stroke. Our findings might, in the future, lead to new brain network‐informed imaging biomarkers and improved prognostication in ischemic stroke.

Presence of Blastocystis in gut microbiota is associated with cognitive traits and decreased executive function

Growing evidence implicates the gut microbiome in cognition. Blastocystis is a common gut single-cell eukaryote parasite frequently detected in humans but its potential involvement in human pathophysiology has been poorly characterized. Here we describe how the presence of Blastocystis in the gut microbiome was associated with deficits in executive function and altered gut bacterial composition in a discovery (n = 114) and replication cohorts (n = 942). We also found that Blastocystis was linked to bacterial functions related to aromatic amino acids metabolism and folate-mediated pyrimidine and one-carbon metabolism. Blastocystis-associated shifts in bacterial functionality translated into the circulating metabolome. Finally, we evaluated the effects of microbiota transplantation. Donor's Blastocystis subtypes led to altered recipient's mice cognitive function and prefrontal cortex gene expression. In summary, Blastocystis warrant further consideration as a novel actor in the gut microbiome-brain axis.

Association of White Blood Cell Count With Clinical Outcome Independent of Treatment With Alteplase in Acute Ischemic Stroke

Introduction

Higher white blood cell (WBC) count is associated with poor functional outcome in acute ischemic stroke (AIS). However, little is known about whether the association is modified by treatment with intravenous alteplase.

Methods

WAKE-UP was a randomized controlled trial of the efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in unknown onset stroke. WBC count was measured on admission and again at 22–36 h after randomization to treatment (follow-up). Favorable outcome was defined by a score of 0 or 1 on the modified Rankin scale (mRS) 90 days after stroke. Further outcome were stroke volume and any hemorrhagic transformation (HT) that were assessed on follow-up CT or MRI. Multiple logistic regression analysis was used to assess the association between outcome and WBC count and treatment group.

Results

Of 503 randomized patients, WBC count and baseline parameters were available in 437 patients (μ = 64.7 years, 35.2% women) on admission and 355 patients (μ = 65.1 years, 34.1% women) on follow-up. Median WBC count on admission was 7.6 × 10⁹/L (interquartile range, IQR, 6.1–9.4 × 10⁹/L) and 8.2 × 10⁹/L (IQR, 6.7–9.7 × 10⁹/L) on follow-up. Higher WBC count both on admission and follow-up was associated with lower odds of favorable outcome, adjusted for age, National Institutes of Health (NIH) Stroke Scale Score, temperature, and treatment (alteplase vs. placebo, adjusted odds ratio, aOR 0.85, 95% confidence interval [CI] 0.78–0.94 and aOR 0.88, 95% CI 0.79–0.97). No interaction between WBC count and treatment group was observed (p = 0.11). Furthermore, WBC count on admission and follow-up was significantly associated with HT (aOR 1.14, 95% CI 1.05–1.24 and aOR 1.13, 95% CI 1.00–1.26). Finally, WBC count on follow-up was associated with larger stroke volume (aOR 2.57, 95% CI 1.08–6.07).

Conclusion

Higher WBC count is associated with unfavorable outcome, an increased risk of HT, and larger stroke volume, independent of treatment with alteplase. Whether immunomodulatory manipulation of WBC count improves stroke outcome needs to be tested.

Trial Registration

ClinicalTrials.gov Identifier: NCT01525290.

Microbiota alterations in proline metabolism impact depression

The microbiota-gut-brain axis has emerged as a novel target in depression, a disorder with low treatment efficacy. However, the field is dominated by underpowered studies focusing on major depression not addressing microbiome functionality, compositional nature, or confounding factors. We applied a multi-omics approach combining pre-clinical models with three human cohorts including patients with mild depression. Microbial functions and metabolites converging onto glutamate/GABA metabolism, particularly proline, were linked to depression. High proline consumption was the dietary factor with the strongest impact on depression. Whole-brain dynamics revealed rich club network disruptions associated with depression and circulating proline. Proline supplementation in mice exacerbated depression along with microbial translocation. Human microbiota transplantation induced an emotionally impaired phenotype in mice and alterations in GABA-, proline-, and extracellular matrix-related prefrontal cortex genes. RNAi-mediated knockdown of proline and GABA transporters in Drosophila and mono-association with L. plantarum, a high GABA producer, conferred protection against depression-like states. Targeting the microbiome and dietary proline may open new windows for efficient depression treatment.

Caudovirales bacteriophages are associated with improved executive function and memory in flies, mice, and humans

Growing evidence implicates the gut microbiome in cognition. Viruses, the most abundant life entities on the planet, are a commonly overlooked component of the gut virome, dominated by the Caudovirales and Microviridae bacteriophages. Here, we show in a discovery (n = 114) and a validation cohort (n = 942) that subjects with increased Caudovirales and Siphoviridae levels in the gut microbiome had better performance in executive processes and verbal memory. Conversely, increased Microviridae levels were linked to a greater impairment in executive abilities. Microbiota transplantation from human donors with increased specific Caudovirales (>90% from the Siphoviridae family) levels led to increased scores in the novel object recognition test in mice and up-regulated memory-promoting immediate early genes in the prefrontal cortex. Supplementation of the Drosophila diet with the 936 group of lactococcal Siphoviridae bacteriophages resulted in increased memory scores and upregulation of memory-involved brain genes. Thus, bacteriophages warrant consideration as novel actors in the microbiome-brain axis.

Diffusion-Weighted Imaging and Fluid-Attenuated Inversion Recovery Quantification to Predict Diffusion-Weighted Imaging-Fluid-Attenuated Inversion Recovery Mismatch Status in Ischemic Stroke With Unknown Onset

BACKGROUND

Visual rating of diffusion-weighted imaging (DWI)-fluid-attenuated inversion recovery (FLAIR) mismatch can be challenging. We evaluated quantification of DWI and FLAIR to predict DWI-FLAIR mismatch status in ischemic stroke.

METHODS

In screened patients from the WAKE-UP trial (Efficacy and Safety of Magnetic Resonance Imaging-Based Thrombolysis in Wake-Up Stroke), we retrospectively studied relative DWI (rDWI SI) and FLAIR signal intensity (rFLAIR SI). We defined the optimal mean rFLAIR SI and interquartile range of the rDWI SI in the DWI lesion to predict DWI-FLAIR mismatch status. We investigated agreement between each quantitative parameter and the DWI-FLAIR mismatch and the association between both quantitative parameters. We evaluated the predictive value of the quantitative parameters for excellent functional outcome by logistic regression, adjusted for DWI lesion volume, treatment, age, and National Institutes of Health Stroke Scale score.

RESULTS

In the rFLAIR and rDWI SI analysis, 213/369 and 241/421 subjects respectively had a DWI-FLAIR mismatch. A mean rFLAIR SI cutoff of 1.09 and interquartile range rDWI SI cutoff of 0.47 were optimal to predict the DWI-FLAIR mismatch with a sensitivity and specificity of 77% (95% CI, 71%-83%) and 67% (95% CI, 59%-74%), and 76% (95% CI, 70%-81%) and 72% (95% CI, 65%-79%), respectively. For both quantitative parameters, agreement with the DWI-FLAIR mismatch was fair (73%, κ=0.44 [95% CI, 0.35-0.54] for rFLAIR and 74%, κ=0.48 [95% CI, 0.39-0.56] for rDWI). Both quantitative parameters correlated moderately (Pearson R=0.54 [95% CI, 0.46-0.61], P<0.001, n=367). The interquartile range rDWI SI (n=188), but not the mean rFLAIR SI (n=172), was an independent predictor of excellent functional outcome (odds ratio, 0.67 per 0.1 unit increase of interquartile range rDWI SI, 95% CI, 0.51-0.89, P=0.01).

CONCLUSIONS

Agreement between the quantitative and qualitative approach may be insufficient to advocate DWI or FLAIR quantification as alternative for visual rating.

Obesity-associated deficits in inhibitory control are phenocopied to mice through gut microbiota changes in one-carbon and aromatic amino acids metabolic pathways

BACKGROUND

Inhibitory control (IC) is critical to keep long-term goals in everyday life. Bidirectional relationships between IC deficits and obesity are behind unhealthy eating and physical exercise habits.

METHODS

We studied gut microbiome composition and functionality, and plasma and faecal metabolomics in association with cognitive tests evaluating inhibitory control (Stroop test) and brain structure in a discovery (n=156), both cross-sectionally and longitudinally, and in an independent replication cohort (n=970). Faecal microbiota transplantation (FMT) in mice evaluated the impact on reversal learning and medial prefrontal cortex (mPFC) transcriptomics.

RESULTS

An interplay among IC, brain structure (in humans) and mPFC transcriptomics (in mice), plasma/faecal metabolomics and the gut metagenome was found. Obesity-dependent alterations in one-carbon metabolism, tryptophan and histidine pathways were associated with IC in the two independent cohorts. Bacterial functions linked to one-carbon metabolism (thyX,dut, exodeoxyribonuclease V), and the anterior cingulate cortex volume were associated with IC, cross-sectionally and longitudinally. FMT from individuals with obesity led to alterations in mice reversal learning. In an independent FMT experiment, human donor's bacterial functions related to IC deficits were associated with mPFC expression of one-carbon metabolism-related genes of recipient's mice.

CONCLUSION

These results highlight the importance of targeting obesity-related impulsive behaviour through the induction of gut microbiota shifts.

Estimating nocturnal stroke onset times by magnetic resonance imaging in the WAKE-UP trial

BACKGROUND

Fluid-attenuated inversion recovery (FLAIR) sequences have gained a role to guide treatment of patients with unknown time of stroke symptom onset. Evolution of signal intensities in FLAIR is associated with time since stroke onset with continuous linear increases.

AIMS

Estimating symptom onset during night-sleep in patients from the WAKE-UP trial based on relative signal intensities FLAIR (FLAIR-rSI) from acute stroke lesions an independent dataset (PRE-FLAIR study).

METHODS

FLAIR-rSI was quantified in stroke lesions in PRE-FLAIR and WAKE-UP. The PRE-FLAIR study was a multicenter observational trial establishing FLAIR as a surrogate parameter for time since stroke onset. WAKE-UP was a randomized controlled trial that revealed a benefit for alteplase in patients selected based on a DWI-FLAIR mismatch. Stroke onset times were recorded in PRE-FLAIR and used to fit a linear regression model with FLAIR-rSI, adjusted for patient age and lesion volume. The model was applied to FLAIR-rSI of stroke lesions to estimate onset times in those patients enrolled in WAKE-UP who had symptom onset during night-sleep.

RESULTS

FLAIR-rSI was quantified in 399 patients from PRE-FLAIR. Linear regression indicated a significant association of age (p = 0.001), lesion volume (p = 0.005) and FLAIR-rSI (p < 0.001) with time since symptom onset (adjusted R²= 0.179). In 813 patients from WAKE-UP, distribution of times of last seen well, symptom recognition and MRI examination were recorded. Median times of last seen well were 1 h before midnight (IQR 2.4 h) and symptom recognition 7 h after midnight (IRQ 2.2 h). Based on the FLAIR-rSI profiles, we estimated median stroke onset 6.1 h after midnight (IQR 2.7 h).

CONCLUSION

Nocturnal strokes during night-sleep may predominantly occur during the early morning hours. Our results are in line with evidence of characteristic diurnal patterns of cardiovascular events.

Cerebral Microbleeds and Treatment Effect of Intravenous Thrombolysis in Acute Stroke: An Analysis of the WAKE-UP Randomized Clinical Trial

Background and Objectives

Cerebral microbleeds (CMBs) are common in patients with acute ischemic stroke and are associated with increased risk of intracerebral hemorrhage (ICH) after intravenous thrombolysis. Whether CMBs modify the treatment effect of thrombolysis is unknown.

Methods

We performed a prespecified analysis of the prospective randomized controlled multicenter Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial including patients with acute ischemic stroke with unknown time of symptom onset and diffusion-weighted imaging–fluid-attenuated inversion recovery mismatch on MRI receiving alteplase or placebo. Patients were screened and enrolled between September 2012 and June 2017 (with final follow-up in September 2017). Patients were randomized to treatment with IV thrombolysis with alteplase at 0.9 mg/kg body weight or placebo. CMB status (presence, number, and distribution) was assessed after study completion by 3 raters blinded to clinical information following a standardized protocol. Outcome measures were excellent functional outcome at 90 days, defined by modified Rankin Scale (mRS) score ≤1, and symptomatic ICH according to National Institutes of Neurological Disease and Stroke trial criteria 22 to 36 hours after treatment.

Results

Of 503 patients enrolled in the WAKE-UP trial, 459 (91.3%; 288 [63%] men) were available for analysis. Ninety-eight (21.4%) had at least 1 CMB on baseline imaging; 45 (9.8%) had exactly 1 CMB; 37 (8.1%) had 2 to 4 CMBs; and 16 (3.5%) had ≥5 CMBs. Presence of CMBs was associated with a nonsignificant increased risk of symptomatic ICH (11.2% vs 4.2%; adjusted odds ratio [OR] 2.32, 95% confidence interval [CI] 0.99–5.43, p = 0.052) but had no effect on functional outcome at 90 days (mRS score ≤1: 45.8% vs 50.7%; adjusted OR 0.99, 95% CI 0.59–1.64, p = 0.955). Patients receiving alteplase had better functional outcome (mRS score ≤1: 54.6% vs 44.6%, adjusted OR 1.61, 95% CI 1.07–2.43, p = 0.022) without evidence of heterogeneity in relation to CMB presence (p of the interactive term = 0.546). Results were similar for subpopulations with strictly lobar (presumed cerebral amyloid angiopathy related) or not strictly lobar CMB distribution.

Discussion

In the randomized-controlled WAKE-UP trial, we saw no evidence of reduced treatment effect of alteplase in patients with acute ischemic stroke with ≥1 CMBs. Additional studies are needed to determine the treatment effect of alteplase and its benefit-harm ratio in patients with a larger number of CMBs.

Trial Registration Information

ClinicalTrials.gov identifier NCT01525290; ClinicalTrialsRegister.EU identifier 2011-005906-32.

Classification of Evidence

This study provides Class II evidence that for patients with acute ischemic stroke with unknown time of onset and diffusion-weighted imaging–fluid-attenuated inversion recovery mismatch who received IV alteplase, CMBs are not significantly associated with functional outcome at 90 days.

Cost-Effectiveness of Magnetic Resonance Imaging-Guided Thrombolysis for Patients With Stroke With Unknown Time of Onset

OBJECTIVES

Patients waking up with stroke symptoms are often excluded from intravenous thrombolysis with alteplase (IV-tpa). The WAKE-UP trial, a European multicenter randomized controlled trial, proved the clinical effectiveness of magnetic resonance imaging-guided IV-tpa for these patients. This analysis aimed to assess the cost-effectiveness of the intervention compared to placebo.

METHODS

A Markov model was designed to analyze the cost-effectiveness over a 25-year time horizon. The model consisted of an inpatient acute care phase and a rest-of-life phase. Health states were defined by the modified Rankin Scale (mRS). Initial transition probabilities to mRS scores were based on WAKE-UP data and health state utilities on literature search. Costs were based on data from the University Medical Center Hamburg-Eppendorf, literature, and expert opinion. Incremental costs and effects over the patients' lifetime were estimated. The analysis was conducted from a formal German healthcare perspective. Univariate and probabilistic sensitivity analyses were performed.

RESULTS

Treatment with IV-tpa resulted in cost savings of €51 009 and 1.30 incremental gains in quality-adjusted life-years at a 5% discount rate. Univariate sensitivity analysis revealed incremental cost-effectiveness ratio being sensitive to the relative risk of favorable outcome on mRS for placebo patients after stroke, the costs of long-term care for patients with mRS 4, and patient age at initial stroke event. In all cases, IV-tpa remained cost-effective. Probabilistic sensitivity analysis proved IV-tpa cost-effective in >95% of the simulations results.

CONCLUSIONS

Magnetic resonance imaging-guided IV-tpa compared to placebo is cost-effective in patients with ischemic stroke with unknown time of onset.

Game-theoretical mapping of fundamental brain functions based on lesion deficits in acute stroke

Lesion analysis is a fundamental and classical approach for inferring the causal contributions of brain regions to brain function. However, many studies have been limited by the shortcomings of methodology or clinical data. Aiming to overcome these limitations, we here use an objective multivariate approach based on game theory, Multi-perturbation Shapley value Analysis, in conjunction with data from a large cohort of 394 acute stroke patients, to derive causal contributions of brain regions to four principal functional components of the widely used National Institutes of Health Stroke Score measure. The analysis was based on a high-resolution parcellation of the brain into 294 grey and white matter regions. Through initial lesion symptom mapping for identifying all potential candidate regions and repeated iterations of the game-theoretical approach to remove non-significant contributions, the analysis derived the smallest sets of regions contributing to each of the four principal functional components as well as functional interactions among the regions. Specifically, the factor 'language and consciousness' was related to contributions of cortical regions in the left hemisphere, including the prefrontal gyrus, the middle frontal gyrus, the ventromedial putamen and the inferior frontal gyrus. Right and left motor functions were associated with contributions of the left and right dorsolateral putamen and the posterior limb of the internal capsule, correspondingly. Moreover, the superior corona radiata and the paracentral lobe of the right hemisphere as well as the right caudal area 23 of the cingulate gyrus were mainly related to left motor function, while the prefrontal gyrus, the external capsule and the sagittal stratum fasciculi of the left hemisphere contributed to right motor function. Our approach demonstrates a practically feasible strategy for applying an objective lesion inference method to a high-resolution map of the human brain and distilling a small, characteristic set of grey and white matter structures contributing to fundamental brain functions. In addition, we present novel findings of synergistic interactions between brain regions that provide insight into the functional organization of brain networks.

Serious Adverse Events and Their Impact on Functional Outcome in Acute Ischemic Stroke in the WAKE-UP Trial

BACKGROUND AND PURPOSE

During the first days and weeks after an acute ischemic stroke, patients are prone to complications that can influence further treatment, recovery, and functional outcome. In clinical trials, severe complications are recorded as serious adverse events (SAE). We analyzed the effect of SAE on functional outcome and predictors of SAE in the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke).

METHODS

We performed a post hoc analysis of WAKE-UP, a multicenter, randomized, placebo-controlled clinical trial of magnetic resonance imaging-guided intravenous thrombolysis with alteplase in patients with acute ischemic stroke and unknown time of onset. Functional outcome was assessed by the modified Rankin Scale 90 days after the stroke. SAE were reported to a central safety desk and recorded and categorized by organ system using Medical Dictionary for Regulatory Activities terminology. We used logistic regression analysis to determine the effect of SAE on functional outcome and linear multiple regression analysis to identify baseline predictors of SAE.

RESULTS

Among 503 patients randomized, 199 SAE were reported for n=110 (22%) patients. Of those patients who did suffer a SAE, 20 (10%) had a fatal outcome. Patients suffering from at least one SAE had a lower odds of reaching a favorable outcome (modified Rankin Scale score of 0-1) at 90 days (adjusted odds ratio, 0.36 [95% CI, 0.21-0.61], P<0.001). Higher age (P=0.04) and male sex (P=0.01) were predictors for the occurrence of SAE.

CONCLUSIONS

SAEs were observed in about one in 5 patients, were more frequent in elderly and male patients and were associated with worse functional outcome. These results may help to assess the risk of SAE in future stroke trials and create awareness for severe complications after stroke in clinical practice.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01525290 and https://eudract.ema.europa.eu; Unique identifier: 2011-005906-32.

24-hour blood pressure variability and treatment effect of intravenous alteplase in acute ischaemic stroke

Introduction

To assess the association between 24 h blood pressure variability (BPV) on functional outcome and treatment effect of intravenous alteplase in acute ischaemic stroke.

Patients and methods

In all patients with acute ischaemic stroke of unknown onset randomised in the WAKE-UP (Efficacy and Safety of magnetic resonance imaging [MRI]-based Thrombolysis in Wake-Up Stroke) trial, blood pressure (BP) was measured before randomisation and after initiation of treatment at regular intervals up to 24 hours. Individual BPV was measured by coefficient of variation (CV) of all BP values. Primary outcome measure was favourable outcome defined by a modified Rankin Scale (mRS) score 0 or 1 at 90 days after stroke.

Results

BP measurements were available for 498 of 503 patients randomised (177 women [35.5%], mean age [SD] of 65.2 [11.5] years). Systolic BPV was not associated with the treatment effect of thrombolysis (test for interaction, p = 0.46). The adjusted odds ratio (aOR) for favourable outcome with alteplase, adjusted for age, stroke severity and baseline BP on admission, did not show an association across the quintiles of increasing systolic BPV with an aOR 1.89 (95% confidence interval [CI], 0.76-4.70) in the lowest quintile to aOR 1.05 (95% CI, 0.43-2.56) in the highest quintile. Higher mean systolic BP was associated with a smaller treatment effect of thrombolysis with a significant interaction (p = 0.033). The aOR for favourable outcome with alteplase decreased with quintiles of increasing mean systolic BP from aOR 3.16 (95% CI, 1.26-7.93) in the lowest quintile to aOR 0.84 (95% CI, 0.34-2.10) in in the highest quintile.

Conclusions

There was a significant interaction between mean systolic BP and treatment effect of thrombolysis with higher mean systolic BP being associated with poorer outcome. BPV was not associated with outcome after thrombolysis.ClinicalTrials.gov identifier NCT01525290.

Hyperintense acute reperfusion marker associated with hemorrhagic transformation in the WAKE-UP trial

Introduction

Hyperintense acute reperfusion marker (HARM) is an indicator of early disruption of the blood-brain-barrier. Our aim was to investigate the incidence of HARM in patients with a diffusion weighted imaging (DWI) - fluid attenuated inversion recovery (FLAIR) mismatch and determine the association between this marker and hemorrhagic complications as well as clinical outcome.

Patients and Methods

We included patients from the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial who underwent baseline perfusion weighted imaging (PWI). HARM was defined as a hyperintense signal in the cerebrospinal fluid space on FLAIR imaging at 24 h after baseline imaging. We compared baseline characteristics in patients with and without HARM and investigated the association between HARM and any hemorrhagic transformation (HT) and parenchymal hematoma (PH) in a multivariate logistic regression. We also explored HARM as an independent predictor of poor outcome, defined as a modified Rankin Scale of 3-6 at 90 days.

Results

HARM was present in 14 of 223 (6%) patients with a DWI-FLAIR mismatch and baseline characteristics were similar in patients with vs without HARM. HARM showed an independent relationship with any HT (OR 6.67; 95%CI 1.72-26.58) and any PH (OR 6.92; 95%CI 1.34-29.49). The rate of HARM was similar in patients with good and poor outcome (5%, p = 0.90).

Conclusion

In the WAKE-UP trial, the incidence of HARM was only 6% at 24 h. An association was present between HARM and hemorrhagic complications, but no relationship with functional outcome was observed.

Influence of stroke infarct location on quality of life assessed in a multivariate lesion-symptom mapping study

Stroke has a deleterious impact on quality of life. However, it is less well known if stroke lesions in different brain regions are associated with reduced quality of life (QoL). We therefore investigated this association by multivariate lesion-symptom mapping. We analyzed magnetic resonance imaging and clinical data from the WAKE-UP trial. European Quality of Life 5 Dimensions (EQ-5D) 3 level questionnaires were completed 90 days after stroke. Lesion symptom mapping was performed using a multivariate machine learning algorithm (support vector regression) based on stroke lesions 22-36 h after stroke. Brain regions with significant associations were explored in reference to white matter tracts. Of 503 randomized patients, 329 were included in the analysis (mean age 65.4 years, SD 11.5; median NIHSS = 6, IQR 4-9; median EQ-5D score 90 days after stroke 1, IQR 0-4, median lesion volume 3.3 ml, IQR 1.1-16.9 ml). After controlling for lesion volume, significant associations between lesions and EQ-5D score were detected for the right putamen, and internal capsules of both hemispheres. Multivariate lesion inference analysis revealed an association between injuries of the cortico-spinal tracts with worse self-reported quality of life 90 days after stroke in comparably small stroke lesions, extending previous reports of the association of striato-capsular lesions with worse functional outcome. Our findings are of value to identify patients at risk of impaired QoL after stroke.

Reversible Edema in the Penumbra Correlates With Severity of Hypoperfusion

[Figure: see text].

Preserved structural connectivity mediates the clinical effect of thrombolysis in patients with anterior-circulation stroke

Thrombolysis with recombinant tissue plasminogen activator in acute ischemic stroke aims to restore compromised blood flow and prevent further neuronal damage. Despite the proven clinical efficacy of this treatment, little is known about the short-term effects of systemic thrombolysis on structural brain connectivity. In this secondary analysis of the WAKE-UP trial, we used MRI-derived measures of infarct size and estimated structural network disruption to establish that thrombolysis is associated not only with less infarct growth, but also with reduced loss of large-scale connectivity between grey-matter areas after stroke. In a causal mediation analysis, infarct growth mediated a non-significant 8.3% (CI95% [-8.0, 32.6]%) of the clinical effect of thrombolysis on functional outcome. The proportion mediated jointly through infarct growth and change of structural connectivity, especially in the border zone around the infarct core, however, was as high as 33.4% (CI95% [8.8, 77.4]%). Preservation of structural connectivity is thus an important determinant of treatment success and favourable functional outcome in addition to lesion volume. It might, in the future, serve as an imaging endpoint in clinical trials or as a target for therapeutic interventions.

Whole-Brain Dynamics in Aging: Disruptions in Functional Connectivity and the Role of the Rich Club

Normal aging causes disruptions in the brain that can lead to cognitive decline. Resting-state functional magnetic resonance imaging studies have found significant age-related alterations in functional connectivity across various networks. Nevertheless, most of the studies have focused mainly on static functional connectivity. Studying the dynamics of resting-state brain activity across the whole-brain functional network can provide a better characterization of age-related changes. Here, we employed two data-driven whole-brain approaches based on the phase synchronization of blood-oxygen-level-dependent signals to analyze resting-state fMRI data from 620 subjects divided into two groups (middle-age group (n = 310); age range, 50-64 years versus older group (n = 310); age range, 65-91 years). Applying the intrinsic-ignition framework to assess the effect of spontaneous local activation events on local-global integration, we found that the older group showed higher intrinsic ignition across the whole-brain functional network, but lower metastability. Using Leading Eigenvector Dynamics Analysis, we found that the older group showed reduced ability to access a metastable substate that closely overlaps with the so-called rich club. These findings suggest that functional whole-brain dynamics are altered in aging, probably due to a deficiency in a metastable substate that is key for efficient global communication in the brain.

Effect of intravenous alteplase on post-stroke depression in the WAKE UP trial

BACKGROUND AND PURPOSE

The aim was to study the effect of intravenous alteplase on the development of post-stroke depression (PSD) in acute stroke patients, and to identify predictors of PSD.

METHODS

This post hoc analysis included patients with unknown onset stroke randomized to treatment with alteplase or placebo in the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290), in whom a composite end-point of PSD was defined as a Beck Depression Inventory ≥10, medication with an antidepressant, or depression recorded as an adverse event. Multiple logistic regression was used to identify predictors of PSD at 90 days. Structural equation modelling was applied to assess the indirect effect of thrombolysis on PSD mediated by the modified Rankin Scale.

RESULTS

Information on the composite end-point was available for 438 of 503 randomized patients. PSD was present in 96 of 224 (42.9%) patients in the alteplase group and 115 of 214 (53.7%) in the placebo group (odds ratio 0.63; 95% confidence interval 0.43-0.94; p = 0.022; adjusted for age and National Institutes of Health Stroke Scale at baseline). Prognostic factors associated with PSD included baseline medication with antidepressants, higher lesion volume, history of depression and assignment to placebo. While 65% of the effect of thrombolysis on PSD were caused directly, 35% were mediated by an improvement of the mRS.

CONCLUSIONS

Treatment with alteplase in patients with acute stroke resulted in lower rates of depression at 90 days, which were only partially explained by reduced functional disability. Predictors of PSD including history and clinical characteristics may help in identifying patients at risk of PSD.

Abstract P352: Reversible Relative FLAIR Signal Intensity Changes in the Penumbra Correlate With Severity of Hypoperfusion

In ischemic stroke, the study of edema, measurable as fluid attenuated inversion recovery (FLAIR) signal increase, has mainly focused on the ischemic core and less on the surrounding penumbra. To the naked eye, no FLAIR changes are present in the penumbra. However, changes in perfusion status could induce physiological changes resulting in subtle penumbral FLAIR signal alterations. To investigate penumbral FLAIR changes, we included subjects from the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) and Granulocyte Colony-Stimulating Factor in Patients With Acute Ischemic Stroke (AXIS 2) trial with perfusion- and diffusion-weighted imaging (PWI, DWI) and FLAIR at baseline. We used RAPID software to calculate the core and perfusion lesion on DWI and PWI and selected subjects with a minimal mismatch volume (15 ml) and ratio (1.2). We created voxel-based relative FLAIR signal intensity (rFLAIR SI) maps at baseline and follow up (FU) by calculating the ratio of the FLAIR intensity in one voxel and the median FLAIR intensity in a sphere with 15 mm radius around a contralateral homologues voxel. We studied rFLAIR SI in two regions of interest: the baseline penumbra (baseline perfusion lesion - [core lesion + voxels with apparent diffusion coefficient <620 10 -6 mm 2 /s]) and the non-infarcted penumbra (baseline perfusion lesion - FU FLAIR lesion) at 24 hours (WAKE-UP) or 30 days (AXIS 2). Severity of hypoperfusion was defined as the time to maximum of the residue function. In the baseline penumbra, rFLAIR SI was elevated (ratio=1.04, p=1.7*10 -13 , n=126) and correlated with severity of hypoperfusion (Pearson’s r 0.03, p<1.0*10 -4 , n=126). At 24 hours in a subgroup from WAKE-UP, rFLAIR SI in the non-infarcted penumbra further increased (ratio=1.05 at 24h vs 1.03 at baseline, p=7.1*10 -3 , n=43). In a different subgroup from AXIS 2, this increase in rFLAIR SI was reversible (ratio=1.02 at 30d vs 1.04 at baseline, p=1.5*10 -3 n=26) since it was no longer different from 1 at 30 days (ratio=1.01 at 30 days, p=0.099, n=26). Increases in rFLAIR SI, likely representing edema, are not restricted to the ischemic core and correlate with severity of hypoperfusion in the penumbra. They appear early after stroke onset, further increase at 24 hours and are reversible by 30 days.

Extent of FLAIR Hyperintense Vessels May Modify Treatment Effect of Thrombolysis: A Post hoc Analysis of the WAKE-UP Trial

Background and Aims: Fluid-attenuated inversion recovery (FLAIR) hyperintense vessels (FHVs) on MRI are a radiological marker of vessel occlusion and indirect sign of collateral circulation. However, the clinical relevance is uncertain. We explored whether the extent of FHVs is associated with outcome and how FHVs modify treatment effect of thrombolysis in a subgroup of patients with confirmed unilateral vessel occlusion from the randomized controlled WAKE-UP trial.

Methods: One hundred sixty-five patients were analyzed. Two blinded raters independently assessed the presence and extent of FHVs (defined as the number of slices with visible FHV multiplied by FLAIR slice thickness). Patients were then separated into two groups to distinguish between few and extensive FHVs (dichotomization at the median <30 or ≥30).

Results: Here, 85% of all patients (n = 140) and 95% of middle cerebral artery (MCA) occlusion patients (n = 127) showed FHVs at baseline. Between MCA occlusion patients with few and extensive FHVs, no differences were identified in relative lesion growth (p = 0.971) and short-term [follow-up National Institutes of Health Stroke Scale (NIHSS) score; p = 0.342] or long-term functional recovery [modified Rankin Scale (mRS) <2 at 90 days poststroke; p = 0.607]. In linear regression analysis, baseline extent of FHV (defined as a continuous variable) was highly associated with volume of hypoperfused tissue (β = 2.161; 95% CI 0.96–3.36; p = 0.001). In multivariable regression analysis adjusted for treatment group, stroke severity, lesion volume, occlusion site, and recanalization, FHV did not modify functional recovery. However, in patients with few FHVs, the odds for good functional outcome (mRS) were increased in recombinant tissue plasminogen activator (rtPA) patients compared to those who received placebo [odds ratio (OR) = 5.3; 95% CI 1.2–24.0], whereas no apparent benefit was observed in patients with extensive FHVs (OR = 1.1; 95% CI 0.3–3.8), p-value for interaction was 0.11.

Conclusion: While the extent of FHVs on baseline did not alter the evolution of stroke in terms of lesion progression or functional recovery, it may modify treatment effect and should therefore be considered relevant additional information in those patients who are eligible for intravenous thrombolysis.

Clinical Trial Registration: Main trial (WAKE-UP): ClinicalTrials.gov, NCT01525290; and EudraCT, 2011-005906-32. Registered February 2, 2012.

Higher agreement in endovascular treatment decision-making than in parametric quantifications among automated CT perfusion software packages in acute ischemic stroke

BACKGROUND AND OBJECTIVE

Estimates of parameters used to select patients for endovascular thrombectomy (EVT) for acute ischemic stroke differ among software packages for automated computed tomography (CT) perfusion analysis. To determine impact of these differences in decision making, we analyzed intra-observer and inter-observer agreement in recommendations about whether to perform EVT based on perfusion maps from 4 packages.

METHODS

Perfusion CT datasets from 63 consecutive patients with suspected acute ischemic stroke were retrospectively postprocessed with 4 packages of Minerva, RAPID, Olea, and IntelliSpace Portal (ISP). We used Pearson correlation coefficients and Bland-Altman analysis to compare volumes of infarct core, penumbra, and mismatch calculated by Minerva and RAPID. We used kappa analysis to assess agreement among decisions of 3 radiologists about whether to recommend EVT based on maps generated by 4 packages.

RESULTS

We found significant differences between using Minerva and RAPID to estimate penumbra (67.39±41.37mL vs. 78.35±45.38 mL, p < 0.001) and mismatch (48.41±32.03 vs. 61.27±32.73mL, p < 0.001), but not of infarct core (p = 0.230). Pearson correlation coefficients were 0.94 (95%CI:0.90-0.96) for infarct core, 0.87 (95%CI:0.79-0.91) for penumbra, and 0.72 (95%CI:0.57-0.83) for mismatch volumes (p < 0.001). Limits of agreements were (-21.22-25.02) for infarct core volumes, (-54.79-32.88) for penumbra volumes, and (-60.16-34.45) for mismatch volumes. Final agreement for EVT decision-making was substantial between Minerva vs. RAPID (k = 0.722), Minerva vs. Olea (k = 0.761), and RAPID vs. Olea (k = 0.782), but moderate for ISP vs. the other three.

CONCLUSIONS

Despite quantitative differences in estimates of infarct core, penumbra, and mismatch using 4 software packages, their impact on radiologists' decisions about EVT is relatively small.

Safety and efficacy of intravenous thrombolysis in stroke patients on prior antiplatelet therapy in the WAKE-UP trial

Background

One quarter to one third of patients eligible for systemic thrombolysis are on antiplatelet therapy at presentation. In this study, we aimed to assess the safety and efficacy of intravenous thrombolysis in stroke patients on prescribed antiplatelet therapy in the WAKE-UP trial.

Methods

WAKE-UP was a multicenter, randomized, double-blind, placebo-controlled clinical trial to study the efficacy and safety of MRI-guided intravenous thrombolysis with alteplase in patients with an acute stroke of unknown onset time. The medication history of all patients randomized in the WAKE-UP trial was documented. The primary safety outcome was any sign of hemorrhagic transformation on follow-up MRI. The primary efficacy outcome was favorable functional outcome defined by a score of 0–1 on the modified Rankin scale at 90 days after stroke, adjusted for age and baseline stroke severity. Logistic regression models were fitted to study the association of prior antiplatelet treatment with outcome and treatment effect of intravenous alteplase.

Results

Of 503 randomized patients, 164 (32.6%) were on antiplatelet treatment. Patients on antiplatelet treatment were older (70.3 vs. 62.8 years, p <  0.001), and more frequently had a history of hypertension, atrial fibrillation, diabetes, hypercholesterolemia, and previous stroke or transient ischaemic attack. Rates of symptomatic intracranial hemorrhage and hemorrhagic transformation on follow-up imaging did not differ between patients with and without antiplatelet treatment. Patients on prior antiplatelet treatment were less likely to achieve a favorable outcome (37.3% vs. 52.6%, p = 0.014), but there was no interaction of prior antiplatelet treatment with intravenous alteplase concerning favorable outcome (p = 0.355). Intravenous alteplase was associated with higher rates of favorable outcome in patients on prior antiplatelet treatment with an adjusted odds ratio of 2.106 (95% CI 1.047–4.236).

Conclusions

Treatment benefit of intravenous alteplase and rates of post-treatment hemorrhagic transformation were not modified by prior antiplatelet intake among MRI-selected patients with unknown onset stroke. Worse functional outcome in patients on antiplatelets may result from a higher load of cardiovascular co-morbidities in these patients.

Symptoms and probabilistic anatomical mapping of lacunar infarcts

Background

The anatomical distribution of acute lacunar infarcts has mainly been studied for supratentorial lesions. In addition, little is known about the association with distinct stroke symptoms, not summarized as classical lacunar syndromes. We aimed to describe the spatial lesion distribution of acute supra- and infratentorial lacunar infarcts and their association with stroke symptoms in patients eligible for thrombolysis.

Methods

All patients enrolled in the WAKE-UP trial (efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in wake-up stroke) were screened for lacunar infarcts on diffusion-weighted imaging (DWI). The relationship between the anatomical distribution of supra- and infratentorial lacunar infarcts, their demographic characteristics and acute stroke symptoms, defined by the National Institutes of Health Stroke Scale (NIHSS) score, were correlated and compared.

Results

Maps of lesion distribution from 224 lacunar infarct patients (76 [33.9%] females, mean age [standard deviation] of 63.4 [11.5] years) were generated using computational image mapping methods. Median infarct volume was 0.73 ml (interquartile range [IQR] 0.37–1.15 ml). Median NIHSS sum score on hospital arrival was 4 (IQR 3–6). 165 (73.7%) patients had lacunar infarcts in the supratentorial deep white or grey matter, while 59 (26.3%) patients had infratentorial lacunar infarcts. Patients with supratentorial lacunar infarcts presented with a significantly lower occurrence of deficits in the NIHSS items gaze (p < 0.001) and dysarthria (p = 0.008), but had more often a paresis of the left arm (p = 0.009) and left leg (p = 0.068) compared to patients with infratentorial infarcts.

Conclusions

The anatomical lesion distribution of lacunar infarcts reveals a distinct pattern and supports an association of localization with different stroke symptoms.

Trial registration

NCT01525290.

Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data

BACKGROUND

Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers.

METHODS

We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0-1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0-2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4-6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903.

FINDINGS

Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10-2·03]; p=0·011), with low heterogeneity across studies (I²=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05-1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06-2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4-6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52-1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03-4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22-25·50]; p=0·024).

INTERPRETATION

In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death.

FUNDING

None.

Polypharmacy, functional outcome and treatment effect of intravenous alteplase for acute ischaemic stroke

BACKGROUND AND PURPOSE

Polypharmacy is an important challenge in clinical practice. Our aim was to determine the effect of polypharmacy on functional outcome and treatment effect of alteplase in acute ischaemic stroke.

METHODS

This was a post hoc analysis of the randomized, placebo-controlled WAKE-UP trial of magnetic resonance imaging guided intravenous alteplase in unknown onset stroke. Polypharmacy was defined as an intake of five or more medications at baseline. Comorbidities were assessed by the Charlson Comorbidity Index (CCI). The primary efficacy variable was favourable outcome defined by a score of 0-1 on the modified Rankin Scale at 90 days. Logistic regression analysis was used to test for an association of polypharmacy with functional outcome, and for interaction of polypharmacy and the effect of thrombolysis.

RESULTS

Polypharmacy was present in 133/503 (26%) patients. Patients with polypharmacy were older (mean age 70 vs. 64 years; p < 0.0001) and had a higher score on the National Institutes of Health Stroke Scale at baseline (median 7 vs. 5; p = 0.0007). A comorbidity load defined by a CCI score ≥ 2 was more frequent in patients with polypharmacy (48% vs. 8%; p < 0.001). Polypharmacy was associated with lower odds of favourable outcome (adjusted odds ratio 0.50, 95% confidence interval 0.30-0.85; p = 0.0099), whilst the CCI score was not. Treatment with alteplase was associated with higher odds of favourable outcome in both groups, with no heterogeneity of treatment effect (test for interaction of treatment and polypharmacy, p = 0.29).

CONCLUSION

In stroke patients, polypharmacy is associated with worse functional outcome after intravenous thrombolysis independent of comorbidities. However, polypharmacy does not interact with the beneficial effect of alteplase.

Obesity Impairs Short-Term and Working Memory through Gut Microbial Metabolism of Aromatic Amino Acids

The gut microbiome has been linked to fear extinction learning in animal models. Here, we aimed to explore the gut microbiome and memory domains according to obesity status. A specific microbiome profile associated with short-term memory, working memory, and the volume of the hippocampus and frontal regions of the brain differentially in human subjects with and without obesity. Plasma and fecal levels of aromatic amino acids, their catabolites, and vegetable-derived compounds were longitudinally associated with short-term and working memory. Functionally, microbiota transplantation from human subjects with obesity led to decreased memory scores in mice, aligning this trait from humans with that of recipient mice. RNA sequencing of the medial prefrontal cortex of mice revealed that short-term memory associated with aromatic amino acid pathways, inflammatory genes, and clusters of bacterial species. These results highlight the potential therapeutic value of targeting the gut microbiota for memory impairment, specifically in subjects with obesity.

Bariatric Surgery-Induced Changes in Intima-Media Thickness and Cardiovascular Risk Factors in Class 3 Obesity: A 3-Year Follow-Up Study

OBJECTIVE

The impact of weight loss induced by bariatric surgery (BS) and nonsurgical approaches on cardiovascular risk factors (CVRFs) has not been fully elucidated. We assessed the effects of BS and a nonsurgical approach on carotid intima-media thickness (CIMT) and CVRFs in participants with class 3 obesity.

METHODS

A total of 87 participants with obesity (59 women; 46 [37-52] years old; BMI, 43 [40-47]) and 75 controls were recruited; 21 (25%) participants with obesity underwent BS. BMI, blood pressure, cholesterol, triglycerides, fasting plasma glucose, C-reactive protein, CIMT, and Framingham Risk Score were measured at baseline and at 3-year follow-up. Independent factors for reduction in CIMT were analyzed. The literature on the effects of BS and CIMT was reviewed.

RESULTS

After BS, BMI decreased from 45.45 to 27.28 (P < 0.001), and mean CIMT decreased from 0.64 mm (0.56-0.75 mm) to 0.54 mm (0.46-0.65) mm (P < 0.012), equivalent to 0.005 mm/kg of weight lost. At 3-year follow-up, participants who had undergone BS had similar CIMT and CVRFs to the control group. No changes in CVRFs were seen related to the nonsurgical approach. BMI reduction after BS had the strongest independent association with decreased CIMT.

CONCLUSIONS

Weight loss after BS decreases CIMT and CVRFs in middle-aged participants with class 3 obesity, resulting in CIMT similar to that observed in lean participants.

Clinical Characteristics and Outcome of Patients With Hemorrhagic Transformation After Intravenous Thrombolysis in the WAKE-UP Trial

Background: Hemorrhagic transformation (HT) is an important complication of intravenous thrombolysis with alteplase. HT can show a wide range from petechiae to parenchymal hematoma with mass effect with varying clinical impact. We studied clinical and imaging characteristics of patients with HT and evaluated whether different types of HT are associated with functional outcome.

Methods: We performed a post-hoc analysis of WAKE-UP, a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in unknown onset stroke. HT was assessed on follow-up MRI or CT and diagnosed as hemorrhagic infarction type 1 and type 2 (HI1 and HI2, combined as HI), and parenchymal hemorrhage type 1 and type 2 (PH1 and PH2, combined as PH). Severity of stroke symptoms was assessed using the National Institutes of Health Stroke Scale (NIHSS) at baseline. Stroke lesion volume was measured on baseline diffusion weighted imaging (DWI). Primary endpoint was a favorable outcome defined as a modified Rankin Scale score 0–1 at 90 days.

Results: Of 483 patients included in the analysis, 95 (19.7%) showed HI and 21 (4.4%) had PH. Multiple logistic regression analysis identified treatment with alteplase (OR, 2.08 [95% CI, 1.28–3.40]), baseline NIHSS score (OR, 1.11 [95% CI, 1.05–1.17]), DWI lesion volume (OR, 1.03 [95% CI, 1.01–1.05]), baseline glucose levels (OR, 1.01 [95% CI, 1.00–1.01]) and atrial fibrillation (OR, 3.02 [95% CI, 1.57–5.80]) as predictors of any HT. The same parameters predicted HI. Predictors of PH were baseline NIHSS score (OR, 1.11 [95% CI, 1.01–1.22]) and as a trend treatment with alteplase (OR, 2.40 [95% CI, 0.93–6.96]). PH was associated with lower odds of favorable outcome (OR 0.25, 95% [CI 0.05–0.86]), while HI was not.

Conclusion: Our results indicate that HI is associated with stroke severity, cardiovascular risk factors and thrombolysis. PH is a rare complication, more frequent in severe stroke and with thrombolysis. In contrast to HI, PH is associated with worse functional outcome. The impact of HT after MRI-guided intravenous alteplase for unknown onset stroke on clinical outcome is similar as in the trials of stroke thrombolysis within a known early time-window.

Different Mismatch Concepts for Magnetic Resonance Imaging-Guided Thrombolysis in Unknown Onset Stroke

OBJECTIVE

To explore the prevalence of the perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch and response to intravenous thrombolysis in the WAKE-UP trial.

METHODS

We performed a prespecified post hoc analysis of ischemic stroke patients screened for DWI-fluid-attenuated inversion recovery (FLAIR) mismatch in WAKE-UP who underwent PWI. We defined PWI-DWI mismatch as ischemic core volume < 70ml, mismatch volume > 10ml, and mismatch ratio > 1.2. Primary efficacy end point was a modified Rankin Scale score of 0-1 at 90 days, adjusted for age and symptom severity.

RESULTS

Of 1,362 magnetic resonance imaging-screened patients, 431 underwent PWI. Of these, 57 (13%) had a double mismatch, 151 (35%) only a DWI-FLAIR mismatch, and 54 (13%) only a PWI-DWI mismatch. DWI-FLAIR mismatch was more prevalent than PWI-DWI mismatch (48%, 95% confidence interval [CI] = 43-53% vs 26%, 95% CI = 22-30%; p < 0.0001). Screening for either one of the mismatch profiles resulted in a yield of 61% (95% CI = 56-65%). Prevalence of PWI-DWI mismatch was similar in patients with (27%) or without (24%) DWI-FLAIR mismatch (p = 0.52). In an exploratory analysis in the small subgroup of 208 randomized patients with PWI, PWI-DWI mismatch status did not modify the treatment response (p for interaction = 0.73).

INTERPRETATION

Evaluating both the DWI-FLAIR and PWI-DWI mismatch patterns in patients with unknown time of stroke onset will result in the highest yield of thrombolysis treatment. The treatment benefit of alteplase in patients with a DWI-FLAIR mismatch seems to be driven not merely by the presence of a PWI-DWI mismatch, although this analysis was underpowered. ANN NEUROL 2020;87:931-938.

Functional Outcome of Intravenous Thrombolysis in Patients With Lacunar Infarcts in the WAKE-UP Trial

Importance

The rationale for intravenous thrombolysis in patients with lacunar infarcts is debated, since it is hypothesized that the microvascular occlusion underlying lacunar infarcts might not be susceptible to pharmacological reperfusion treatment.

Objective

To study the efficacy and safety of intravenous thrombolysis among patients with lacunar infarcts.

Design, Setting, and Participants

This exploratory secondary post hoc analysis of the WAKE-UP trial included patients who were screened and enrolled between September 2012 and June 2017 (with final follow-up in September 2017). The WAKE-UP trial was a multicenter, double-blind, placebo-controlled randomized clinical trial to study the efficacy and safety of intravenous thrombolysis with alteplase in patients with an acute stroke of unknown onset time, guided by magnetic resonance imaging. All 503 patients randomized in the WAKE-UP trial were reviewed for lacunar infarcts. Diagnosis of lacunar infarcts was based on magnetic resonance imaging and made by consensus of 2 independent investigators blinded to clinical information.

Main Outcomes and Measures

The primary efficacy variable was favorable outcome defined by a score of 0 to 1 on the modified Rankin Scale at 90 days after stroke, adjusted for age and severity of symptoms.

Results

Of the 503 patients randomized in the WAKE-UP trial, 108 patients (including 74 men [68.5%]) had imaging-defined lacunar infarcts, whereas 395 patients (including 251 men [63.5%]) had nonlacunar infarcts. Patients with lacunar infarcts were younger than patients with nonlacunar infarcts (mean age [SD], 63 [12] years vs 66 [12] years; P = .003). Of patients with lacunar infarcts, 55 (50.9%) were assigned to treatment with alteplase and 53 (49.1%) to receive placebo. Treatment with alteplase was associated with higher odds of favorable outcome, with no heterogeneity of treatment outcome between lacunar and nonlacunar stroke subtypes. In patients with lacunar strokes, a favorable outcome was observed in 31 of 53 patients (59%) in the alteplase group compared with 24 of 52 patients (46%) in the placebo group (adjusted odds ratio [aOR], 1.67 [95% CI, 0.77-3.64]). There was 1 death and 1 symptomatic intracranial hemorrhage according to Safe Implementation of Thrombolysis in Stroke-Monitoring Study criteria in the alteplase group, while no death and no symptomatic intracranial hemorrhage occurred in the placebo group. The distribution of the modified Rankin Scale scores 90 days after stroke also showed a nonsignificant shift toward better outcomes in patients with lacunar infarcts treated with alteplase, with an adjusted common odds ratio of 1.94 (95% CI, 0.95-3.93).

Conclusions and Relevance

While the WAKE-UP trial was not powered to demonstrate the efficacy of treatment in subgroups of patients, the results indicate that the association of intravenous alteplase with functional outcome does not differ in patients with imaging-defined lacunar infarcts compared with those experiencing other stroke subtypes.

Abstract P2-12-05: Neuropsychological assessment, neuroimaging, and tumor markers to explore cognitive decline in early stage breast cancer patients

Background. It is widely demonstrated that a high percentage of early stage breast cancer patients achieves a long-term survival. However, it seems that some of them show a cognitive decline during and after the oncology treatment, affecting their quality of life. Fortunately, the neuropsychological impairment in cancer patients is nowadays a known issue in oncology literature. Our aim is to assess the effects of chemotherapy and endocrine therapy on neurocognitive functions in patients with early stage breast cancer. If the hypothesis that the patients suffer from neurocognitive impairments related to the oncology treatment will be confirmed, this would imply the possibility of an early neuropsychological rehabilitation since the first diagnosis, to prevent the worsening of the quality of life and to avoid the use of additional medications to regulate for example the severity of fatigue and mood. Methods. The study population includes 45 patients diagnosed of breast cancer undergoing chemotherapy +/- endocrine treatment (CT), 15 patients undergoing endocrine treatment (HT), and 9 healthy controls (HC). Throughout each evaluation at three points time, we administered the Mini-Mental State Examination (MMSE), some tests of the Cogstateneurocognitive battery, the Trail Making Test (TMTA and TMTB), and the Controlled Oral Word Association Test (COWAT). Moreover, each subject was asked to complete the EORTC QLQ-C30 and the QLQ-BR23 quality of life tests, the MD Anderson Symptoms Inventory questionnaire, the Hospital Anxiety and Depression scale, and a self-report of the neurocognitive impairment perceived. In addition, we are performing a pilot neuroimaging study aimed to enroll 20 patients with early stage breast cancer, of whom 10 treated with chemotherapy, and 10 with hormone therapy alone. Patients undergo a structural and functional brain magnetic resonance imaging (fMRI). S100 protein, and neuro specific enolase are also collected to explore their possible relationship with the neurocognitive decline. Results. Both CT and HT Groups performed lower results than HC in visuo-motor processing speed test (TMTA) at baseline and at month 12 (p=0.00). At month 6 only the HT Group had lower results than HC (p=0.00). We found a correlation between the lower results of TMTA and the level of depression (p=0.02), distress (p=0.00), anxiety (p=0.01), severity of symptoms (p=0.00) in CT Group at baseline. The MMSE scores were slightly lower in both CT and HT Groups compared to HC (p=0.04) at month 6. The MMSE results at month 12 were lower in HT Groups compared to HC (p=0.04). In addition, the neurocognitive impairment perceived is higher in CT Group (p&lt;0.00) once having stopped the chemotherapy treatment until the last follow up. The results of TMTB and COWAT increased in CT Group during the last follow up (p=0.00), and it seems to have a positive correlation with the neurocognitive tasks the patients performed (p=0.02 and p=0.03 respectively). Concerning the pilot study, we analysed the first 10 patients enrolled in the study: 5 subjects treated with chemotherapy and 5 with hormone therapy alone. No statistically significant differences were found concerning the alteration of the tumor markers values. On the contrary, we found changes between the baseline and the post-treatment brain fMRI. Conclusions. Our results suggest a decline in few cognitive domains in cancer patients as consequence of the oncology treatment. In some tests the neurocognitive decline was also observed in cancer groups at baseline, and it was associated with the low state of mind in CT Group. We infer that the increasing of scores in CT Group at month 12 was positively associated with the cognitive tasks the patients were performing during the study-period.

Citation Format: Claudia Panciroli, Carles Biarnes, Josep Puig, Jose Anton Anton, Vanesa Quiroga, Eudald Felip, Beatriz Cirauqui, Margarita Romeo, Iris Teruel, Salvador Pedraza, Mireia Margeli. Neuropsychological assessment, neuroimaging, and tumor markers to explore cognitive decline in early stage breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-12-05.

From "Time is Brain" to "Imaging is Brain": A Paradigm Shift in the Management of Acute Ischemic Stroke

Arterial recanalization to restore the blood supply and limit the brain damage is the primary goal in the management of acute ischemic stroke (AIS). Since the publication of pivotal randomized clinical trials in 2015, endovascular thrombectomy has become part of the standard of care in selected cases of AIS from large-vessel occlusions up to 6 hours after the onset of symptoms. However, the association between endovascular reperfusion and improved functional outcome is not strictly time dependent. Rather than on rigid time windows, candidates should be selected based on vascular and physiologic information. This approach places imaging data at the center of treatment decisions. Advances in imaging-based management of AIS provide crucial information about vessel occlusion, infarct core, ischemic penumbra, and degree of collaterals. This information is invaluable in identifying patients who are likely to benefit from reperfusion therapies and excluding those who are unlikely to benefit or are at risk of adverse effects. The approach to reperfusion therapies continues to evolve, and imaging is acquiring a greater role in the diagnostic work-up and treatment decisions as shown in recent clinical trials with extended time window. The 2018 American Heart Association/American Stroke Association guidelines reflect a paradigm shift in the management of AIS from "Time is Brain" to "Imaging is Brain." This review discusses the essential role of multimodal imaging developing from recent trials on therapy for AIS.

Abstract WP86: MRI-Guided Mismatch Imaging to Identify Patients for Thrombolysis in the Unknown Time Window: Insights From the WAKE-UP Trial

Background: Two imaging paradigms, the diffusion-weighted imaging (DWI) - fluid attenuated inversion recovery (FLAIR) and perfusion-weighted imaging (PWI) - DWI mismatch, used in the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) and Extending the Time for Thrombolysis in Emergency Neurological Deficits (EXTEND) trial respectively, can identify patients eligible for thrombolysis if stroke onset time is unknown.

Objectives: We explored presence and influence of the PWI-DWI mismatch on outcome in WAKE-UP.

Methods: We included patients screened for DWI-FLAIR mismatch in WAKE-UP who also underwent PWI. We defined PWI-DWI mismatch according to EXTEND as core <70 ml, mismatch ratio >1.2 and mismatch volume >10 ml. Primary efficacy end point was favorable outcome defined as modified Rankin Scale score of 0-1, adjusted for age and symptom severity.

Results: The analysis included 343 screened patients of which 162 were randomized and treated. Of 343 screened patients, 162 had a DWI-FLAIR mismatch, 80 had a PWI-DWI mismatch and of those, 36 had both mismatches. Proportions of PWI-DWI mismatch did not differ in those with (22%, 36/162) vs without (24%, 44/181) DWI-FLAIR mismatch (p=0.74). PWI-DWI mismatch status did not modify treatment effect of thrombolysis (p for interaction=.68). In patients with both DWI-FLAIR and PWI-DWI mismatch, favorable outcome was present in 52% of those treated with alteplase (11/21) vs 38% (5/13) in those receiving placebo (adjusted OR 2.02; 95% CI 0.44-9.24, p=0.36). Selection based on the presence of the DWI-FLAIR mismatch identified more thrombolysis eligible patients (47%; 95% CI 42%-53%) compared to the PWI-DWI mismatch (23%; 95% CI 19%-28%, p<.0001). Screening for either one of the mismatch profiles resulted in a yield of 60% (95% CI 55%-65%) candidates for thrombolysis.

Conclusion: We did not identify an association between the DWI-FLAIR and PWI-DWI mismatch. PWI-DWI mismatch status did not modify treatment effect in patients with DWI-FLAIR mismatch, but the analysis was underpowered. Screening for the presence of either one of the mismatch profiles with MRI seems the most inclusive approach to identify patients who can still benefit from thrombolysis in the unknown time window after stroke onset.

Introducing Online Continuing Education in Radiology for General Practitioners

The aim of this study was to determine whether e-learning as a new teaching methodology was acceptable for general practitioners in continuous education courses of radiology. Generally, these courses are face-to-face with the corresponding time and place limitations. To overcome these limitations, we transformed one of these courses to an online one evaluating its acceptance. The course was about thorax radiology and it was delivered to 249 participants. The experiment was carried out in two phases: Phase 1, as a pilot testing with 12 general practitioners (G1), and Phase 2, with 149 general practitioners (G2), 12 radiologists (G3) and 76 medical residents (G4). All participants evaluated the course design, the delivering e-learning platform, and the course contents using a five-point Likert scale (satisfaction level from 1 to 5). Collected data was analysed using t, Mann-Whitney U and Kruskal-Wallis tests. In Phase 1, the rounded scores of all questions except one surpassed 3.5. In Phase 2, all the rounded scores surpassed 4.0 indicating that a total agreement on all items was achieved. All collected impressions indicate the high acceptance of the proposed methodology.

Quantitative Signal Intensity in Fluid-Attenuated Inversion Recovery and Treatment Effect in the WAKE-UP Trial

Background and Purpose—

Relative signal intensity of acute ischemic stroke lesions in fluid-attenuated inversion recovery (fluid-attenuated inversion recovery relative signal intensity [FLAIR-rSI]) magnetic resonance imaging is associated with time elapsed since stroke onset with higher intensities signifying longer time intervals. In the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke Trial), intravenous alteplase was effective in patients with unknown onset stroke selected by visual assessment of diffusion weighted imaging fluid-attenuated inversion recovery mismatch, that is, in those with no marked fluid-attenuated inversion recovery hyperintensity in the region of the acute diffusion weighted imaging lesion. In this post hoc analysis, we investigated whether quantitatively measured FLAIR-rSI modifies treatment effect of intravenous alteplase.

Methods—

FLAIR-rSI of stroke lesions was measured relative to signal intensity in a mirrored region in the contralesional hemisphere. The relationship between FLAIR-rSI and treatment effect on functional outcome assessed by the modified Rankin Scale (mRS) after 90 days was analyzed by binary logistic regression using different end points, that is, favorable outcome defined as mRS score of 0 to 1, independent outcome defined as mRS score of 0 to 2, ordinal analysis of mRS scores (shift analysis). All models were adjusted for National Institutes of Health Stroke Scale at symptom onset and stroke lesion volume.

Results—

FLAIR-rSI was successfully quantified in stroke lesions in 433 patients (86% of 503 patients included in WAKE-UP). Mean FLAIR-rSI was 1.06 (SD, 0.09). Interaction of FLAIR-rSI and treatment effect was not significant for mRS score of 0 to 1 ( P =0.169) and shift analysis ( P =0.086) but reached significance for mRS score of 0 to 2 ( P =0.004). We observed a smooth continuing trend of decreasing treatment effects in relation to clinical end points with increasing FLAIR-rSI.

Conclusions—

In patients in whom no marked parenchymal fluid-attenuated inversion recovery hyperintensity was detected by visual judgement in the WAKE-UP trial, higher FLAIR-rSI of diffusion weighted imaging lesions was associated with decreased treatment effects of intravenous thrombolysis. This parallels the known association of treatment effect and elapsing time of stroke onset.

Current Smoking Does Not Modify the Treatment Effect of Intravenous Thrombolysis in Acute Ischemic Stroke Patients-A Post-hoc Analysis of the WAKE-UP Trial

Background: The “smoking paradox” indicates that patients with acute ischemic stroke (AIS) who smoke at the time of their stroke may have a better prognosis after intravenous thrombolysis than non-smokers. However, findings are inconsistent and data analyzing the effect of smoking on treatment efficacy of intravenous thrombolysis are scarce.

Methods: We performed a pre-specified post-hoc subgroup analysis of the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial that randomized AIS patients with unknown time of symptom onset who had diffusion-weighted imaging-fluid attenuation inversion recovery (DWI-FLAIR) mismatch to either alteplase or placebo. Patients were categorized as current smokers or non-smokers (including former smokers and never-smokers). Baseline demographic and clinical characteristics, as well as clinical and imaging follow-up data were analyzed according to smoking status.

Results: Four hundred and eighty six patients were included in the analysis. Current smokers (133, 27.4%) were younger (60.1 ± 13.0 vs. 67.2 ± 10.3 years; p < 0.001) and less often had arterial hypertension (45.0% vs. 56.8%; p = 0.02) or atrial fibrillation (3.8% vs. 15.3%; p < 0.001). The acute stroke presentation was more often due to large vessel occlusion among current smokers (27.1 vs. 16.2%; p = 0.01), and smokers had a trend towards more severe strokes (National Institutes of Health Stroke Scale score>10 in 27.1% vs. 19.5%; p = 0.08). The treatment effect of alteplase, quantified as odds ratio for a favorable outcome (modified Rankin Scale [mRS] score at 90 days of 0 or 1), did not differ between current smokers and non-smokers (p-value for interaction: 0.59). After adjustment for age and stroke severity, neither the proportion of patients with favorable outcome, nor the median mRS score at 90 days differed between current smokers and non-smokers. When additional potential confounders were included in the model, the median mRS score was higher in current smokers than in non-smokers (cOR of better outcome for current smokers vs. non-smokers: 0.664 [0.451–0.978], p = 0.04).

Conclusions: In patients with mild to moderate MRI-proven AIS and unknown time of symptom onset with DWI-FLAIR mismatch, current smokers had worse functional outcome as compared to non-smokers. Current smoking did not modify the treatment effect of alteplase.

Clinical Trial registration: Main trial (WAKE-UP): ClinicalTrials.gov, NCT01525290; and EudraCT, 2011-005906-32. Registered 02 February 2012.

Post-hoc Analysis of Outcome of Intravenous Thrombolysis in Infarcts of Infratentorial Localization in the WAKE-UP Trial

Introduction: In WAKE-UP (Efficacy and Safety of MRI-based Thrombolysis in Wake-Up Stroke), patients with an acute stroke of unknown onset time were randomized to treatment with intravenous alteplase or placebo, guided by MRI. Methods: In this exploratory post-hoc secondary analysis we compared clinical and imaging data, as well as treatment effects and safety of intravenous thrombolysis between patients with infra- vs. supratentorial stroke. Results: Forty-eight out of 503 randomized patients (9.5%) presented with a stroke involving the cerebellum or brainstem. Patients with infratentorial stroke were younger compared to patients with supratentorial stroke (mean age 60 vs. 66 years), more frequently male (85 vs. 62%), and less severely affected (median NIHSS 4.5 vs. 6.0). There was no heterogeneity for treatment effect between supratentorial (OR 1.67 95% CI 1.11-2.51) and infratentorial (OR 1.31 95% CI 0.41-4.22) sub-groups (test for interaction p = 0.70). In patients with infratentorial stroke, favorable outcome [a score of 0-1 on the modified Rankin scale (mRS) at 90 days] was observed in 12/22 patients (54.5%) in the alteplase group and in 13/25 patients (52.0%) in the placebo group (p = 0.59). The primary safety endpoint (death or mRS 4-6 at day 90) occurred in three patients of the alteplase group (13.6%) and three patients in the placebo group (12.0%); p = 0.74. Discussion: WAKE-UP was underpowered for demonstrating treatment effect in subgroup analyses however, based on our current results, there is no evidence to recommend withholding MRI-guided thrombolysis in patients with unknown onset stroke of infratentorial localization.