High relative cerebral blood volume is associated with good long term clinical outcomes in acute ischemic stroke: a retrospective cohort study.

BACKGROUND: Endovascular therapy for acute ischemic stroke has been shown to be highly effective in selected patients. However, the ideal criteria for patient selection are still debated. It is well known that collateral flow is an important factor, but the assessment is often subjective and time-consuming. Relative cerebral blood volume (rCBV) is a putative indicator of collateral capacity and can be quickly and easily determined by automated quantitative analysis. We investigated the relationship between rCBV of the affected region and clinical outcome in patients with acute ischemic stroke after endovascular therapy. METHODS: We conducted a retrospective study on consecutive patients between January 2017 and May 2019. Patients with acute ischemic stroke of the anterior circulation who underwent imaging including computed tomography perfusion and were treated with mechanical thrombectomy (MT) were eligible for inclusion. rCBV was calculated automatically with RAPID software by dividing the average cerebral blood volume (CBV) of the affected region (time-to-maximum (Tmax) > 6 s) by the CBV of the unaffected contralateral side. The primary outcome was determined by the modified Rankin Scale (mRS) after 90 days. Good clinical outcome was defined as mRS ≤ 2. We compared means, performed mono- and multivariate logistical regression and calculated a receiver operating characteristic (ROC)-analysis to determine the ideal cutoff value to predict clinical outcomes. RESULTS: 155 patients were enrolled in this study. 66 patients (42.58%) had good clinical outcomes. Higher rCBV was associated with good clinical outcome (p < 0.001), even after adjustment for the patients' status according to mRS and National Institute of Health Stroke Scale (NIHSS) age and Alberta stroke program early computed tomography score (ASPECTS) at baseline (p = 0.006). ROC-analysis revealed 0.650 (confidence interval: 0.616-0.778) as the optimal cutoff value. CONCLUSION: Higher rCBV at baseline is associated with good clinical long-term outcomes in patients with acute ischemic stroke treated by MT. In this study we provide the biggest collective so far that gives evidence that rCBV can be a valuable tool to identify patients who might benefit from MT and are able give a threshold to help to offer patients MT in borderline cases.

Impact of brain volume and intracranial cerebrospinal fluid volume on the clinical outcome in endovascularly treated stroke patients.

PURPOSE: Previously, brain volume (BV) and intracranial cerebrospinal fluid volume (CSFV) have been investigated regarding clinical outcomes of subgroups of ischemic stroke patients. This study aimed to examine if the preexisting, preischemic BV and CSFV have an impact on good functional outcome and mortality in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). METHODS: Preischemic BV, CSFV, and CSFV/Total intracranial volume (TICV)-ratio were calculated with a fully automated segmentation platform. Univariate and multivariate analyses were used to study associations. RESULTS: In this retrospective study 107 subsequent AIS patients of a prospective database were included. The segmentation results of the fully automated algorithm based on non-contrast computerized tomography scans (NCCT) correlated significantly with the segmentation results obtained from 3D T1 weighted magnetic resonance images (P < 0.001). In the univariate analysis a preexisting BV (P < 0.001), preexisting CSFV (P = 0.009), and the ratio CSFV/total intracranial volume (P < 0.001) each significantly correlated with good functional outcome and mortality. However, in the multivariate regression analysis, also correcting for patient age, none of these volumes remained to correlate with these outcome parameters. CONCLUSION: In summary, an association of BV, CSFV, and the CSFV/TICV-ratio with good functional outcome and mortality in AIS treated with MT could not be established. A fully automated segmentation algorithm based on NCCT was successfully developed in-house for calculating the volumes of interest.

High-risk plaque features can be detected in non-stenotic carotid plaques of patients with ischaemic stroke classified as cryptogenic using combined (18)F-FDG PET/MR imaging.

PURPOSE: The aim of this study was to investigate in 18 patients with ischaemic stroke classified as cryptogenic and presenting non-stenotic carotid atherosclerotic plaques the morphological and biological aspects of these plaques with magnetic resonance imaging (MRI) and (18)F-fluoro-deoxyglucose positron emission tomography ((18)F-FDG PET) imaging. METHODS: Carotid arteries were imaged 150 min after injection of (18)F-FDG with a combined PET/MRI system. American Heart Association (AHA) lesion type and plaque composition were determined on consecutive MRI axial sections (n = 460) in both carotid arteries. (18)F-FDG uptake in carotid arteries was quantified using tissue to background ratio (TBR) on corresponding PET sections. RESULTS: The prevalence of complicated atherosclerotic plaques (AHA lesion type VI) detected with high-resolution MRI was significantly higher in the carotid artery ipsilateral to the ischaemic stroke as compared to the contralateral side (39 vs 0 %; p = 0.001). For all other AHA lesion types, no significant differences were found between ipsilateral and contralateral sides. In addition, atherosclerotic plaques classified as high-risk lesions with MRI (AHA lesion type VI) were associated with higher (18)F-FDG uptake in comparison with other AHA lesions (TBR = 3.43 ± 1.13 vs 2.41 ± 0.84, respectively; p < 0.001). Furthermore, patients presenting at least one complicated lesion (AHA lesion type VI) with MRI showed significantly higher (18)F-FDG uptake in both carotid arteries (ipsilateral and contralateral to the stroke) in comparison with carotid arteries of patients showing no complicated lesion with MRI (mean TBR = 3.18 ± 1.26 and 2.80 ± 0.94 vs 2.19 ± 0.57, respectively; p < 0.05) in favour of a diffuse inflammatory process along both carotid arteries associated with complicated plaques. CONCLUSION: Morphological and biological features of high-risk plaques can be detected with (18)F-FDG PET/MRI in non-stenotic atherosclerotic plaques ipsilateral to the stroke, suggesting a causal role for these plaques in stroke. Combined (18)F-FDG PET/MRI systems might help in the evaluation of patients with ischaemic stroke classified as cryptogenic.

Systemic thrombolysis in anterior spinal artery syndrome: what has to be considered?

Anterior spinal artery syndrome (ASAS) often leads to complete motor paralysis with poor clinical outcome. There is a lack of controlled clinical trials on acute treatment strategies in ASAS. However, systemic thrombolysis with recombinant tissue-plasminogen activator (rt-PA) might be a useful therapeutic option in ASAS. We report the management of a patient with ASAS below thoracic level 10, who was treated with intravenous thrombolysis. An 81 year old patient presented with flaccid paraplegia. After exclusion of aortal dissection, spinal tumour or haemorrhage, the patient was treated with intravenous rt-PA 3 h 40 min after symptom onset. The follow up magnetic resonance imaging (MRI) showed spinal infarction below thoracic segment 10. In the clinical course, the patient partially recovered lower limb muscle strength and was able to walk with assistance. To the best of our knowledge, this is the first case in the literature of ASAS with MRI-proven spinal ischemia and the application of rt-PA. Systemic thrombolysis seems to be justifiable in patients with ASAS after the rule-out of aortal dissection and spinal bleeding.

Interdisciplinary Rendez-Vous Approach in Endovascular Stroke Treatment: A New Concept to Accelerate Mechanical Thrombectomy in Primary Stroke Centers.

PURPOSE: Prompt endovascular treatment of patients with stroke due to intracranial Large Vessel Occlusion (LVO) is a major challenge in rural areas because neurointerventionalists are usually not available. As a result, treatment is delayed, and clinical outcomes are worse compared with patients primarily treated in comprehensive stroke centers (CSC). To address this problem, we present a concept in which interdisciplinary, on-site endovascular treatment is performed in a Primary Stroke Center (PSC) by a team of interventional neuroradiologists and cardiologists: the Rendez-Vous approach. METHODS: Thirty-five patients with LVO who underwent interdisciplinary thrombectomy on-site at the PSC as part of the Rendez-Vous concept were compared with 72 patients who were transferred from a PSCs to the CSC for thrombectomy when diagnosed with LVO in terms of temporal sequences and clinical outcomes. RESULTS: Patients treated on-site at the PSC as part of the Rendez-Vous approach were managed as successfully and without an increase in complication rates compared with patients treated secondarily at a CSC (91.7% successful interventions in Rendez-Vous vs. 87.3% in control group, p = 0.57). The time from diagnosis of LVO to groin puncture was reduced by mean 74.3 min with the Rendez-Vous concept (p < 0.01). Regarding the clinical outcome, a functionally independent status was achieved in 45.5% in the Rendez-Vous group and in 22.6% in the control group (p = 0.029). CONCLUSION: Thanks to interdisciplinary teamwork between cardiology and interventional neuroradiology in local PSCs, times to successful reperfusion can be reduced. This has a potentially positive impact on the clinical outcome of stroke patients.

Endovascular thrombectomy is cost-saving in patients with acute ischemic stroke with large infarct.

Objective: Endovascular thrombectomy (EVT) is the standard of care for acute large vessel occlusion stroke. Recently, the ANGEL-ASPECT and SELECT 2 trials showed improved outcomes in patients with acute ischemic Stroke presenting with large infarcts. The cost-effectiveness of EVT for this subpopulation of stroke patients has only been calculated using data from the previously published RESCUE-Japan LIMIT trial. It is, therefore, limited in its generalizability to an international population. With this study we primarily simulated patient-level costs to analyze the economic potential of EVT for patients with large ischemic stroke from a public health payer perspective based on the recently published data and secondarily identified determinants of cost-effectiveness. Methods: Costs and outcome of patients treated with EVT or only with the best medical care based on the recent prospective clinical trials ANGEL-ASPECT, SELECT2 and RESCUE-Japan LIMIT. A A Markov model was developed using treamtment outcomes derived from the most recent available literature. Deterministic and probabilistic sensitivity analyses addressed uncertainty. Results: Endovascular treatment resulted in an incremental gain of 1.32 QALYs per procedure with cost savings of $17,318 per patient. Lifetime costs resulted to be most sensitive to the costs of the endovascular procedure. Conclusion: EVT is a cost-saving (i.e., dominant) strategy for patients presenting with large ischemic cores defined by inclusion criteria of the recently published ANGEL-ASPECT, SELECT2, and RESCUE-Japan LIMIT trials in comparison to best medical care in our simulation. Prospective data of individual patients need to be collected to validate these results.

LST-AI: a Deep Learning Ensemble for Accurate MS Lesion Segmentation.

Automated segmentation of brain white matter lesions is crucial for both clinical assessment and scientific research in multiple sclerosis (MS). Over a decade ago, we introduced an engineered lesion segmentation tool, LST. While recent lesion segmentation approaches have leveraged artificial intelligence (AI), they often remain proprietary and difficult to adopt. As an open-source tool, we present LST-AI, an advanced deep learning-based extension of LST that consists of an ensemble of three 3D-UNets. LST-AI explicitly addresses the imbalance between white matter (WM) lesions and non-lesioned WM. It employs a composite loss function incorporating binary cross-entropy and Tversky loss to improve segmentation of the highly heterogeneous MS lesions. We train the network ensemble on 491 MS pairs of T1w and FLAIR images, collected in-house from a 3T MRI scanner, and expert neuroradiologists manually segmented the utilized lesion maps for training. LST-AI additionally includes a lesion location annotation tool, labeling lesion location according to the 2017 McDonald criteria (periventricular, infratentorial, juxtacortical, subcortical). We conduct evaluations on 103 test cases consisting of publicly available data using the Anima segmentation validation tools and compare LST-AI with several publicly available lesion segmentation models. Our empirical analysis shows that LST-AI achieves superior performance compared to existing methods. Its Dice and F1 scores exceeded 0.62, outperforming LST, SAMSEG (Sequence Adaptive Multimodal SEGmentation), and the popular nnUNet framework, which all scored below 0.56. Notably, LST-AI demonstrated exceptional performance on the MSSEG-1 challenge dataset, an international WM lesion segmentation challenge, with a Dice score of 0.65 and an F1 score of 0.63-surpassing all other competing models at the time of the challenge. With increasing lesion volume, the lesion detection rate rapidly increased with a detection rate of >75% for lesions with a volume between 10mm3 and 100mm3. Given its higher segmentation performance, we recommend that research groups currently using LST transition to LST-AI. To facilitate broad adoption, we are releasing LST-AI as an open-source model, available as a command-line tool, dockerized container, or Python script, enabling diverse applications across multiple platforms.

LST-AI: A deep learning ensemble for accurate MS lesion segmentation.

Automated segmentation of brain white matter lesions is crucial for both clinical assessment and scientific research in multiple sclerosis (MS). Over a decade ago, we introduced an engineered lesion segmentation tool, LST. While recent lesion segmentation approaches have leveraged artificial intelligence (AI), they often remain proprietary and difficult to adopt. As an open-source tool, we present LST-AI, an advanced deep learning-based extension of LST that consists of an ensemble of three 3D U-Nets. LST-AI explicitly addresses the imbalance between white matter (WM) lesions and non-lesioned WM. It employs a composite loss function incorporating binary cross-entropy and Tversky loss to improve segmentation of the highly heterogeneous MS lesions. We train the network ensemble on 491 MS pairs of T1-weighted and FLAIR images, collected in-house from a 3T MRI scanner, and expert neuroradiologists manually segmented the utilized lesion maps for training. LST-AI also includes a lesion location annotation tool, labeling lesions as periventricular, infratentorial, and juxtacortical according to the 2017 McDonald criteria, and, additionally, as subcortical. We conduct evaluations on 103 test cases consisting of publicly available data using the Anima segmentation validation tools and compare LST-AI with several publicly available lesion segmentation models. Our empirical analysis shows that LST-AI achieves superior performance compared to existing methods. Its Dice and F1 scores exceeded 0.62, outperforming LST, SAMSEG (Sequence Adaptive Multimodal SEGmentation), and the popular nnUNet framework, which all scored below 0.56. Notably, LST-AI demonstrated exceptional performance on the MSSEG-1 challenge dataset, an international WM lesion segmentation challenge, with a Dice score of 0.65 and an F1 score of 0.63-surpassing all other competing models at the time of the challenge. With increasing lesion volume, the lesion detection rate rapidly increased with a detection rate of >75% for lesions with a volume between 10 mm3 and 100 mm3. Given its higher segmentation performance, we recommend that research groups currently using LST transition to LST-AI. To facilitate broad adoption, we are releasing LST-AI as an open-source model, available as a command-line tool, dockerized container, or Python script, enabling diverse applications across multiple platforms.

Breaking with a dogma: persisting diffusion restrictions (pDWI) in follow-up after endovascular treatment for stroke.

BACKGROUND: Post-stroke diffusion weighted imaging (DWI) signal transformation of the infarct core, which results in high apparent diffusion coefficient (ADC) values and variable DWI signal intensity, is completed no later than 1 month after onset of ischemia. We observed frequent exceptions to this timeline of change in DWI signal, which led to uncertainties in further clinical patient management. METHODS: A prospective single-center study of patients treated with mechanical thrombectomy of a large vessel occlusion in the anterior circulation was conducted. Patients received high-resolution MRI at 3T, including DWI, in the acute post-stroke phase and in the follow-up after 3-12 months. RESULTS: Overall, 78 patients (45 men) of mean age 63.6 years were evaluated. We identified persisting or new diffusion restriction in 29 of the 78 patients (37.2%) on follow-up imaging. Diffusion restrictions in a different location from the infarct core, representing new (sub-)acute ischemia, were observed in four patients (5.1%). Smaller areas of persisting diffusion restriction (pDWI lesions with high DWI signal and reduced ADC values) within the former infarct core were observed in 25 patients (32.1%) without clinical evidence of recurrent stroke, but with worse outcome scores at follow-up compared with patients without pDWI lesions. The presence of pDWI lesions is associated with a large primary infarct core (multivariate regression OR 1.03 (95% CI 1.01 to 1.05); p<0.01), mediating the relationship between pDWI lesions and clinical outcome. CONCLUSION: Smaller foci of persisting diffusion restriction (pDWI lesions) in the follow-up after endovascular treatment for stroke are frequent and likely represent a slowed ADC signal progression within a formerly large infarct core.

Start, Stop, Continue? The Benefit of Overlapping Intravenous Thrombolysis and Mechanical Thrombectomy : A Matched Case-control Analysis from the German Stroke Registry.

OBJECTIVE: Here we compare the procedural and clinical outcome of patients undergoing thrombectomy with running thrombolysis to matched controls with completed intravenous therapy and an only marginally overlapping activity. METHODS: Patients from 25 sites in Germany were included, who presented with an acute ischemic stroke. Patients' baseline characteristics (including ASPECTS, NIHSS and mRS), grade of reperfusion, and functional outcome 24 h and at day 90 after intervention were extracted from the German Stroke Registry (n = 2566). In a case-control design we stepwise matched the groups due to age, sex and time to groin puncture and time to flow restoration. RESULTS: In the initial cohort (overlap group n = 864, control group n = 1702) reperfusion status (median TICI in overlap group vs. control group: 3 vs. 2b), NIHSS after 24 h, early neurological improvement parameters, mRS at 24 h and at day 90 were significantly better in the overlap group (p < 0.001) with a similar risk of bleeding (2.9% vs. 2.4%) and death (18% vs. 22%). After adjustment mRS at day 90 still showed a trend for lower disability scores in the overlap group (3 IQR 1-5 vs. 3 IQR 1-6, p = 0.09). While comparable bleeding risk could be maintained (4% in both groups), there were significantly more deaths in the control group (18% vs. 30%, p = 0.006). CONCLUSION: The presented results support the approach of continuing and completing a simultaneous administration of intravenous thrombolysis during mechanical thrombectomy procedures.

Incidence, Clinical Significance, and Longitudinal Signal Characteristics of Ischemic Lesions Related to Diagnostic Cerebral Catheter Angiography.

PURPOSE: Cerebral DSA is a routine procedure with few complications. However, it is associated with presumably clinically inapparent lesions detectable on diffusion-weighted MRI imaging (DWI lesions). However, there are insufficient data regarding incidence, etiology, clinical relevance, and longitudinal development of these lesions. This study prospectively evaluated subjects undergoing elective diagnostic cerebral DSA for the occurrence of DWI lesions, potentially associated clinical symptoms and risk factors, and longitudinally monitored the lesions using state-of-the-art MRI. MATERIALS AND METHODS: Eighty-two subjects were examined by high-resolution MRI within 24 h after elective diagnostic DSA and lesion occurrence was qualitatively and quantitatively evaluated. Subjects' neurological status was assessed before and after DSA by clinical neurological examination and a perceived deficit questionnaire. Patient-related risk factors and procedural DSA data were documented. Subjects with lesions received a follow-up MRI and were questioned for neurological deficits after a median of 5.1 months. RESULTS: After DSA, 23(28%) subjects had a total of 54 DWI lesions. Significantly associated risk factors were number of vessels probed, intervention time, age, arterial hypertension, visible calcified plaques, and less examiner experience. Twenty percent of baseline lesions converted to persistent FLAIR lesions at follow-up. After DSA, none of the subjects had a clinically apparent neurological deficit. Self-perceived deficits were nonsignificantly higher at follow-up. CONCLUSION: Cerebral DSA is associated with a considerable number of postinterventional lesions, some persisting as scars in brain tissue. Presumably because of the small lesion size and inconsistent location, no clinically apparent neurological deficits have been observed. However, subtle self-perceived changes may occur. Therefore, special attention is needed to minimize avoidable risk factors.

Outcome and risk of hemorrhage in patients with tandem lesions after endovascular treatment: A propensity score-matched case-control study.

Objectives: Endovascular treatment of acute stroke patients with large vessel occlusions is well established. But tandem lesions of the internal carotid artery and the intracranial anterior circulation remain a challenge regarding the technical conditions and the putative higher risk of hemorrhage due to often required antiplatelet therapy.This study aims to evaluate the clinical outcome and the risk of hemorrhage after endovascular treatment of tandem lesions, with special regard to the periprocedural antiplatelet regimen. Materials and Methods: In this retrospective study, we included 63 consecutive stroke patients with endovascular treated tandem lesions. One hundred eleven patients with a solitary intracranial occlusion were matched using a "propensity score-matched analysis" with the covariates sex, age, wake-up stroke, iv-thrombolysis and NIHSS. Results: Rates of successful recanalization (mTICI 2b/3) and periprocedural complications were equal in both groups (P = 0.19; P = 0.35). The rate of good clinical outcome (mRS≤2) was similar, and the incidence of symptomatic hemorrhages was not significantly different (7.9% tandem lesions vs. 5.4% isolated intracranial occlusion, P = 0.51). Even intensified antiplatelet therapy in patients with tandem lesions did not increase the rate of symptomatic intracranial hemorrhages (P = 0.87). Conclusions: Clinical outcome and symptomatic intracranial hemorrhages did not differ significantly between endovascular treated patients with tandem lesions and matched patients with solitary intracranial occlusions, regardless of the antiplatelet regimen. Therefore, the complex technical requirements for recanalization of a tandem lesion and the putative higher risk should not result in reluctant treatment that would decrease the chance of a good clinical outcome.

Carotid geometry is independently associated with complicated carotid artery plaques.

Introduction: Complicated carotid artery plaques (cCAPs) are associated with an increased risk of rupture and subsequent stroke. The geometry of the carotid bifurcation determines the distribution of local hemodynamics and could thus contribute to the development and composition of these plaques. Therefore, we studied the role of carotid bifurcation geometry in the presence of cCAPs. Methods: We investigated the association of individual vessel geometry with carotid artery plaque types in the Carotid Plaque Imaging in Acute Stroke (CAPIAS) study. After excluding arteries without plaque or with insufficient MRI quality, 354 carotid arteries from 182 patients were analyzed. Individual parameters of carotid geometry [i.e., internal carotid artery (ICA)/common carotid artery (CCA) ratio, bifurcation angle, and tortuosity) were derived from time-of-flight MR images. The lesion types of carotid artery plaques were determined according to the American Heart Association classification of lesions by multi-contrast 3T-MRI. The association between carotid geometry and a cCAP was studied using logistic regression after adjusting for age, sex, wall area, and cardiovascular risk factors. Results: Low ICA/CCA ratios (OR per SD increase 0.60 [95%CI: 0.42-0.85]; p = 0.004) and low bifurcation angles (OR 0.61 [95%CI: 0.42-0.90]; p = 0.012) were significantly associated with the presence of cCAPs after adjusting for age, sex, cardiovascular risk factors, and wall area. Tortuosity had no significant association with cCAPs. Only ICA/CCA ratio remained significant in a model containing all three geometric parameters (OR per SD increase 0.65 [95%CI: 0.45-0.94]; p = 0.023). Conclusions: A steep tapering of the ICA relative to the CCA and, to a lesser extent, a low angle of the carotid bifurcation were associated with the presence of cCAPs. Our findings highlight the contribution of bifurcation geometry to plaque vulnerability. Thus, assessment of carotid geometry could be helpful in identifying patients at risk of cCAPs.

Lesion location across diagnostic regions in multiple sclerosis.

BACKGROUND: Lesions in the periventricular, (juxta)cortical, and infratentorial region, as visible on brain MRI, are part of the diagnostic criteria for Multiple sclerosis (MS) whereas lesions in the subcortical region are currently only a marker of disease activity. It is unknown whether MS lesions follow individual spatial patterns or whether they occur in a random manner across diagnostic regions. AIM: First, to describe cross-sectionally the spatial lesion patterns in patients with MS. Second, to investigate the spatial association of new lesions and lesions at baseline across diagnostic regions. METHODS: Experienced neuroradiologists analyzed brain MRI (3D, 3T) in a cohort of 330 early MS patients. Lesions at baseline and new solitary lesions after two years were segmented (manually and by consensus) and classified as periventricular, (juxta)cortical, or infratentorial (diagnostic regions) or subcortical-with or without Gadolinium-enhancement. Gadolinium enhancement of lesions in the different regions was compared by Chi square test. New lesions in the four regions served as dependent variable in four zero-inflated Poisson models each with the six independent variables of lesions in the four regions at baseline, age and gender. RESULTS: At baseline, lesions were most often observed in the subcortical region (mean 13.0 lesions/patient), while lesion volume was highest in the periventricular region (mean 2287 µl/patient). Subcortical lesions were less likely to show gadolinium enhancement (3.1 %) than juxtacortical (4.3 %), periventricular (5.3 %) or infratentorial lesions (7.2 %). Age was inversely correlated with new periventricular, juxtacortical and subcortical lesions. New lesions in the periventricular, juxtacortical and infratentorial region showed a significant autocorrelative behavior being positively related to the number of lesions in the respective regions at baseline. New lesions in the subcortical region showed a different behavior with a positive association with baseline periventricular lesions and a negative association with baseline infratentorial lesions. CONCLUSION: Across regions, new lesions do not occur randomly; instead, new lesions in the periventricular, juxtacortical and infratentorial diagnostic region are associated with that at baseline. Lesions in the subcortical regions are more closely related to periventricular lesions. Moreover, subcortical lesions substantially contribute to lesion burden in MS but are less likely to show gadolinium enhancement (than lesions in the diagnostic regions).

Mechanical thrombectomy of distal cerebral vessel occlusions of the anterior circulation.

Mechanical thrombectomy (MT) is frequently performed for distal medium vessel occlusions (DMVO) of the anterior circulation in acute stroke patients. However, evidence for its clinical benefit remains scarce. In this study, we aim to investigate clinical course and safety outcomes of MT in comparison to standard medical therapy (SMT) in DMVO. This single-center retrospective observational study included 138 consecutive patients treated for DMVO of the anterior circulation between 2015 and 2021. To reduce the risk of selection bias, propensity score matching (PSM) of patients with MT versus SMT was performed for the covariates NIHSS and mRS at admission. Out of all 138 patients, 48 (34.8%) received MT and 90 (65.2%) received SMT only. Overall, patients treated with MT showed significantly higher NIHSS and mRS scores at admission. Post 1:1 PSM, there was a trend toward a better NIHSS improvement in patients with MT (median 4 vs. 1, P = 0.1). No significant differences were observed in the occurrence of symptomatic intracranial hemorrhage or mortality between the groups before and after PSM. A subgroup analysis showed significantly higher NIHSS improvement (median 5 versus 1, P = 0.01) for patients with successful MT (≥ mTICI 2b). Mechanical thrombectomy for distal medium vessel occlusions (DMVO) in the anterior circulation appeared safe and feasible. Successful recanalization was associated with clinical improvement. Larger, multi-center, randomized-controlled trials are required to corroborate these findings.

Retrospective cohort study to devise a treatment decision score predicting adverse 24-month radiological activity in early multiple sclerosis.

Background: Multiple sclerosis (MS) is a chronic neuroinflammatory disease affecting about 2.8 million people worldwide. Disease course after the most common diagnoses of relapsing-remitting multiple sclerosis (RRMS) and clinically isolated syndrome (CIS) is highly variable and cannot be reliably predicted. This impairs early personalized treatment decisions. Objectives: The main objective of this study was to algorithmically support clinical decision-making regarding the options of early platform medication or no immediate treatment of patients with early RRMS and CIS. Design: Retrospective monocentric cohort study within the Data Integration for Future Medicine (DIFUTURE) Consortium. Methods: Multiple data sources of routine clinical, imaging and laboratory data derived from a large and deeply characterized cohort of patients with MS were integrated to conduct a retrospective study to create and internally validate a treatment decision score [Multiple Sclerosis Treatment Decision Score (MS-TDS)] through model-based random forests (RFs). The MS-TDS predicts the probability of no new or enlarging lesions in cerebral magnetic resonance images (cMRIs) between 6 and 24 months after the first cMRI. Results: Data from 65 predictors collected for 475 patients between 2008 and 2017 were included. No medication and platform medication were administered to 277 (58.3%) and 198 (41.7%) patients. The MS-TDS predicted individual outcomes with a cross-validated area under the receiver operating characteristics curve (AUROC) of 0.624. The respective RF prediction model provides patient-specific MS-TDS and probabilities of treatment success. The latter may increase by 5-20% for half of the patients if the treatment considered superior by the MS-TDS is used. Conclusion: Routine clinical data from multiple sources can be successfully integrated to build prediction models to support treatment decision-making. In this study, the resulting MS-TDS estimates individualized treatment success probabilities that can identify patients who benefit from early platform medication. External validation of the MS-TDS is required, and a prospective study is currently being conducted. In addition, the clinical relevance of the MS-TDS needs to be established.

Complicated Carotid Artery Plaques and Risk of Recurrent Ischemic Stroke or TIA.

BACKGROUND: Complicated nonstenosing carotid artery plaques (CAPs) are an under-recognized cause of stroke. OBJECTIVES: The purpose of this study was to determine whether complicated CAP ipsilateral to acute ischemic anterior circulation stroke (icCAP) are associated with recurrent ischemic stroke or transient ischemic attack (TIA). METHODS: The CAPIAS (Carotid Plaque Imaging in Acute Stroke) multicenter study prospectively recruited patients with ischemic stroke restricted to the territory of a single carotid artery. Complicated (AHA-lesion type VI) CAP were defined by multisequence, contrast-enhanced carotid magnetic resonance imaging obtained within 10 days from stroke onset. Recurrent events were assessed after 3, 12, 24, and 36 months. The primary outcome was recurrent ischemic stroke or TIA. RESULTS: Among 196 patients enrolled, 104 patients had cryptogenic stroke and nonstenosing CAP. During a mean follow-up of 30 months, recurrent ischemic stroke or TIA occurred in 21 patients. Recurrent events were significantly more frequent in patients with icCAP than in patients without icCAP, both in the overall cohort (incidence rate [3-year interval]: 9.50 vs 3.61 per 100 patient-years; P = 0.025, log-rank test) and in patients with cryptogenic stroke (10.92 vs 1.82 per 100 patient-years; P = 0.003). The results were driven by ipsilateral events. A ruptured fibrous cap (HR: 4.91; 95% CI: 1.31-18.45; P = 0.018) and intraplaque hemorrhage (HR: 4.37; 95% CI: 1.20-15.97; P = 0.026) were associated with a significantly increased risk of recurrent events in patients with cryptogenic stroke. CONCLUSIONS: Complicated CAP ipsilateral to acute ischemic anterior circulation stroke are associated with an increased risk of recurrent ischemic stroke or TIA. Carotid plaque imaging identifies high-risk patients who might be suited for inclusion into future secondary prevention trials. (Carotid Plaque Imaging in Acute Stroke [CAPIAS]; NCT01284933).

Complicated Carotid Artery Plaques as a Cause of Cryptogenic Stroke.

BACKGROUND: The underlying etiology of ischemic stroke remains unknown in up to 30% of patients. OBJECTIVES: This study explored the causal role of complicated (American Heart Association-lesion type VI) nonstenosing carotid artery plaques (CAPs) in cryptogenic stroke (CS). METHODS: CAPIAS (Carotid Plaque Imaging in Acute Stroke) is an observational multicenter study that prospectively recruited patients aged older than 49 years with acute ischemic stroke that was restricted to the territory of a single carotid artery on brain magnetic resonance imaging (MRI) and unilateral or bilateral CAP (≥2 mm, NASCET [North American Symptomatic Carotid Endarterectomy Trial] <70%). CAP characteristics were determined qualitatively and quantitatively by high-resolution, contrast-enhanced carotid MRI at 3T using dedicated surface coils. The pre-specified study hypotheses were that that the prevalence of complicated CAP would be higher ipsilateral to the infarct than contralateral to the infarct in CS and higher in CS compared with patients with cardioembolic or small vessel stroke (CES/SVS) as a combined reference group. Patients with large artery stroke (LAS) and NASCET 50% to 69% stenosis served as an additional comparison group. RESULTS: Among 234 recruited patients, 196 had either CS (n = 104), CES/SVS (n = 79), or LAS (n = 19) and complete carotid MRI data. The prevalence of complicated CAP in patients with CS was significantly higher ipsilateral (31%) to the infarct compared with contralateral to the infarct (12%; p = 0.0005). Moreover, the prevalence of ipsilateral complicated CAP was significantly higher in CS (31%) compared with CES/SVS (15%; p = 0.02) and lower in CS compared with LAS (68%; p = 0.003). Lipid-rich and/or necrotic cores in ipsilateral CAP were significantly larger in CS compared with CES/SVS (p < 0.05). CONCLUSIONS: These findings substantiate the role of complicated nonstenosing CAP as an under-recognized cause of stroke. (Carotid Plaque Imaging in Acute Stroke [CAPIAS]; NCT01284933).

Mobilization of CD133+ progenitor cells in patients with acute cerebral infarction.

Progenitor cells (PCs) contribute to the endogenous repair mechanism after ischemic events. Interleukin-8 (IL-8) as part of the acute inflammatory reaction may enhance PC mobilization. Also, statins are supposed to alter number and function of circulating PCs. We aimed to investigate PC mobilization after acute ischemic stroke as well as its association with inflammatory markers and statin therapy. Sixty-five patients with ischemic stroke were enrolled in the study. The number of CD133+ PCs was analyzed by flow cytometry. Blood samples were drawn within 24 hours after symptom onset and after 5 days. The number of CD133+ PCs increased significantly within 5 days (p<0.001). We found no correlation between CD133+ PCs and the serum levels of IL-8, IL-6, or C-reactive protein (CRP). Multivariate analysis revealed that preexisting statin therapy correlated independently with the increase of CD133+ PCs (p=0.001). This study showed a mobilization of CD133+ PCs in patients with acute cerebral infarction within 5 days after symptom onset. The early systemic inflammatory response did not seem to be a decisive factor in the mobilization of PCs. Preexisting statin therapy was associated with the increase in CD133+ PCs, suggesting a potentially beneficial effect of statin therapy in patients with stroke.

MRI plaque imaging detects carotid plaques with a high risk for future cerebrovascular events in asymptomatic patients.

PURPOSE: The aim of this study was to investigate prospectively whether MRI plaque imaging can identify patients with asymptomatic carotid artery stenosis who have an increased risk for future cerebral events. MRI plaque imaging allows categorization of carotid stenosis into different lesion types (I-VIII). Within these lesion types, lesion types IV-V and VI are regarded as rupture-prone plaques, whereas the other lesion types represent stable ones. METHODS: Eighty-three consecutive patients (45 male (54.2%); age 54-88 years (mean 73.2 years)) presenting with an asymptomatic carotid stenosis of 50-99% according to ECST-criteria were recruited. Patients were imaged with a 1.5-T scanner. T1-, T2-, time-of-flight-, and proton-density weighted studies were performed. The carotid plaques were classified as lesion type I-VIII. Clinical endpoints were ischemic stroke, TIA or amaurosis fugax. Survival analysis and log rank test were used to ascertain statistical significance. RESULTS: Six out of 83 patients (7.2%) were excluded: 4 patients had insufficient MR image quality; 1 patient was lost-to-follow-up; 1 patient died shortly after the baseline MRI plaque imaging. The following results were obtained by analyzing the remaining 77 patients. The mean time of follow-up was 41.1 months. During follow-up, n = 9 (11.7%) ipsilateral ischemic cerebrovascular events occurred. Only patients presenting with the high-risk lesion types IV-V and VI developed an ipsilateral cerebrovascular event versus none of the patients presenting with the stable lesion types III, VII, and VIII (n = 9 (11.7%) vs. n = 0 (0%) during follow-up). Event-free survival was higher among patients with the MRI-defined stable lesion types (III, VII, and VIII) than in patients with the high-risk lesion types (IV-V and VI) (log rank test P<0.0001). CONCLUSIONS: MRI plaque imaging has the potential to identify patients with asymptomatic carotid stenosis who are particularly at risk of developing future cerebral ischemia. MRI could improve selection criteria for invasive therapy in the future.