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Abstract The glycoprotein IIb/IIIa antagonist tirofiban has been shown to prevent thromboembolic events during endovascular procedures, but the benefits and risks of its prophylactic early intraprocedural administration for stand-alone coil embolization of acutely ruptured aneurysms are still unclear. We conducted a retrospective single-center analysis of patients treated for aneurysmal subarachnoid hemorrhage with stand-alone coil embolization. Two study cohorts were compared according to the primary prophylactic antithrombotic medication during the procedure: patients receiving only intravenous heparin (HEP) versus patients receiving tirofiban in addition to heparin prior to final aneurysm obliteration (HEP + TF). Outcome endpoints were the incidence of angiographically visible thrombus formation or distal embolization, and the incidence of periprocedural intracranial hemorrhage (ICH). Of 204 cases, 159 were prophylactically treated with HEP and 45 with HEP + TF. Intraprocedural thromboembolic events were less frequent with HEP + TF before and after propensity score matching (PSM) (2.5% vs. 19.7%, p = 0.017). The incidence of ICH and symptomatic ICH did not differ between HEP + TF and HEP before and after PSM (20.5% vs. 30.7%, p = 0.29; and 5.1% vs. 4%, p = 0.88). Early intraprocedural tirofiban administration may be effective in preventing thromboembolic complications during stand-alone coil embolization of acutely ruptured aneurysms without increasing the risk of ICH.

Abstract Background Neurogenic dysphagia is a frequent complication of stroke and is associated with aspiration pneumonia and poor outcomes. Although ischaemic lesion location and size are major determinants of the presence and severity of post‐stroke dysphagia, little is known about the contribution of other acute stroke‐unrelated factors. We aimed to analyse the impact of swallowing and non‐swallowing muscles measurements on swallowing function after large vessel occlusion stroke. Methods This retrospective study was based on a prospective registry of consecutive ischaemic stroke patients. Patients who underwent mechanical thrombectomy between July 2021 and June 2022 and received a flexible endoscopic evaluation of swallowing (FEES) within 5 days after admission were included. Demographic, anthropometric, clinical, and imaging data were collected from the registry. The cross‐sectional areas (CSA) of selected swallowing muscles (as a surrogate marker for swallowing muscle mass) and of cervical non‐swallowing muscles were measured in computed tomography. Skeletal muscle index (SMI) was calculated and used as a surrogate marker for whole body muscle mass. FEES parameters, namely, Functional Oral Intake Scale (FOIS, as a surrogate marker for dysphagia presence and severity), penetration aspiration scale, and the presence of moderate‐to‐severe pharyngeal residues were collected from the clinical records. Univariate and multivariate ordinal and logistic regression analyses were performed to analyse if total CSA of swallowing muscles and SMI were associated with FEES parameters. Results The final study population consisted of 137 patients, 59 were female (43.1%), median age was 74 years (interquartile range 62–83), median baseline National Institutes of Health Stroke Scale score was 12 (interquartile range 7–16), 16 patients had a vertebrobasilar occlusion (11.7%), and successful recanalization was achieved in 127 patients (92.7%). Both total CSA of swallowing muscles and SMI were significantly correlated with age (rho = −0.391, P

(1) Background: Bacterial contamination has been shown to occur during angiographies, although data on its frequency and relevance are sparse. Our aim was to evaluate the incidence of bacterial contamination of syringes used under sterile conditions during neuroangiographies. We sought to differentiate between contamination of the outside of the syringes and the inside and to detect the frequency, extent and germ spectrum of bacterial contamination. (2) Methods: We prospectively collected 600 samples from 100 neuroangiographies. Per angiography, fluid samples from the three routinely used syringes as well as the syringes themselves were analyzed. We analyzed the frequency and extent of contamination and determined the germ spectrum. (3) Results: The majority of samples (56.9%) were contaminated. There was no angiography that showed no contamination (0%). The outer surfaces of the syringes were contaminated significantly more frequently and to a higher extent than the inner surfaces. Both the frequency and extent of contamination of the samples increased with longer duration of angiographic procedures. Most of the bacterial species were environmental or skin germs (87.7%). (4) Conclusions: Bacterial contamination is a frequent finding during neuroangiographies, although its clinical significance is believed to be small. Bacterial contamination increases with longer duration of angiographic procedures.

Abstract Accurate modeling of cerebral hemodynamics is crucial for better understanding the hemodynamics of stroke, for which computational fluid dynamics (CFD) modeling is a viable tool to obtain information. However, a comprehensive study on the accuracy of cerebrovascular CFD models including both transient arterial pressures and flows does not exist. This study systematically assessed the accuracy of different outlet boundary conditions (BCs) comparing CFD modeling and an in-vitro experiment. The experimental setup consisted of an anatomical cerebrovascular phantom and high-resolution flow and pressure data acquisition. The CFD model of the same cerebrovascular geometry comprised five sets of stationary and transient BCs including established techniques and a novel BC, the phase modulation approach. The experiment produced physiological hemodynamics consistent with reported clinical results for total cerebral blood flow, inlet pressure, flow distribution, and flow pulsatility indices (PI). The in-silico model instead yielded time-dependent deviations between 19–66% for flows and 6–26% for pressures. For cerebrovascular CFD modeling, it is recommended to avoid stationary outlet pressure BCs, which caused the highest deviations. The Windkessel and the phase modulation BCs provided realistic flow PI values and cerebrovascular pressures, respectively. However, this study shows that the accuracy of current cerebrovascular CFD models is limited.

Abstract Objective The aims of the study were to (1) characterize the findings of flexible endoscopic evaluation of swallowing (FEES) in stroke patients undergoing mechanical thrombectomy (MT); (2) analyse the screening performance of the Standardized Swallowing Assessment (SSA); and (3) study the impact of FEES‐defined dysphagia on 3‐month outcomes. Methods This single‐centre study was based on a local registry of consecutive acute ischaemic stroke patients undergoing MT during a 1‐year period. Patients received FEES within 5 days of admission regardless of the result of dysphagia screening. We compared baseline demographic and clinical characteristics of patients with and without FEES‐defined dysphagia. We collected 3‐month modified Rankin Scale (mRS) and individual index values of the European Quality of Life 5 Dimensions (EQ‐5D‐iv). Using univariable and multivariable regression analyses we predicted 3‐month outcomes for presence of dysphagia and for FEES‐defined dysphagia severity. Results We included 137 patients with a median age of 74 years, 43.1% were female, median NIHSS was 12 and successful recanalization was achieved in 92.7%. Stroke‐associated pneumonia occurred in 8% of patients. FEES‐defined dysphagia occurred in 81% of patients. Sensitivity of the SSA as a dysphagia screening was 67%. Presence of dysphagia and increasing severity of dysphagia were independently associated with increasing 3‐month mRS score. Increasing dysphagia severity dysphagia was independently associated with lower EQ‐5D‐iv. Interpretation Early FEES‐defined dysphagia occurs in four in every five patients undergoing MT. SSA has a suboptimal dysphagia screening performance. Presence of dysphagia and increasing dysphagia severity predict worse functional outcome and worse health‐related quality‐of‐life.

Acute ischemic stroke caused by large vessel occlusions is being increasingly treated with neurovascular interventions. The hemodynamics within the collateral system of the circle of Willis (CoW) hemodynamics play a fundamental role in therapy success. However, transient in vivo data on pathological collateral flow during large vessel occlusions are not available. Moreover, there are no flow models that accurately simulate the hemodynamic conditions in the CoW during large vessel occlusions. We used a circulatory loop to generate highly reproducible cerebrovascular-like flows and pressures and used non-invasive flow visualization and high-resolution flow and pressure measurements to acquire detailed, time-dependent hemodynamics inside an anatomical phantom of the CoW. After calibrating a physiological reference case, we induced occlusions in the 1. middle cerebral artery, 2. terminal carotid artery, and 3. basilar artery; and measured the left posterior communicating artery flow. Mean arterial pressure and pulse pressure remained unchanged in the different occlusion cases compared to the physiological reference case, while total cerebral flow decreased by up to 19%. In all three occlusion cases, reversed flow was found in the left posterior communicating artery compared to the reference case with different flow magnitudes and pulsatility index values. The experimental results were compared with clinical findings, demonstrating the capability of this realistic cerebrovascular flow setup. This novel cerebrovascular flow setup opens the possibility for investigating different topics of neurovascular interventions under various clinical conditions in controlled preclinical laboratory studies.

Background Data on impact of COVID‐19 vaccination and outcomes of patients with COVID‐19 and acute ischemic stroke undergoing mechanical thrombectomy are scarce. Addressing this subject, we report our multicenter experience. Methods and Results This was a retrospective analysis of patients with COVID‐19 and known vaccination status treated with mechanical thrombectomy for acute ischemic stroke at 20 tertiary care centers between January 2020 and January 2023. Baseline demographics, angiographic outcome, and clinical outcome evaluated by the modified Rankin Scale score at discharge were noted. A multivariate analysis was conducted to test whether these variables were associated with an unfavorable outcome, defined as modified Rankin Scale score >3. A total of 137 patients with acute ischemic stroke (48 vaccinated and 89 unvaccinated) with acute or subsided COVID‐19 infection who underwent mechanical thrombectomy attributable to vessel occlusion were included in the study. Angiographic outcomes between vaccinated and unvaccinated patients were similar (modified Thrombolysis in Cerebral Infarction ≥2b: 85.4% in vaccinated patients versus 86.5% in unvaccinated patients; P=0.859). The rate of functional independence (modified Rankin Scale score, ≤2) was 23.3% in the vaccinated group and 20.9% in the unvaccinated group (P=0.763). The mortality rate was 30% in both groups. In the multivariable analysis, vaccination status was not a significant predictor for an unfavorable outcome (P=0.957). However, acute COVID‐19 infection remained significant (odds ratio, 1.197 [95% CI, 1.007–1.417]; P=0.041). Conclusions Our study demonstrated no impact of COVID‐19 vaccination on angiographic or clinical outcome of COVID‐19–positive patients with acute ischemic stroke undergoing mechanical thrombectomy, whereas worsening attributable to COVID‐19 was confirmed.

Abstract Diffusion-MRI (dMRI) measures molecular diffusion, which allows to characterize microstructural properties of the human brain. Gliomas strongly alter these microstructural properties. Delineation of brain tumors currently mainly relies on conventional MRI-techniques, which are, however, known to underestimate tumor volumes in diffusely infiltrating glioma. We hypothesized that dMRI is well suited for tumor delineation, and developed two different deep-learning approaches. The first diffusion-anomaly detection architecture is a denoising autoencoder, the second consists of a reconstruction and a discrimination network. Each model was exclusively trained on non-annotated dMRI of healthy subjects, and then applied on glioma patients’ data. To validate these models, a state-of-the-art supervised tumor segmentation network was modified to generate groundtruth tumor volumes based on structural MRI. Compared to groundtruth segmentations, a dice score of 0.67 ± 0.2 was obtained. Further inspecting mismatches between diffusion-anomalous regions and groundtruth segmentations revealed, that these colocalized with lesions delineated only later on in structural MRI follow-up data, which were not visible at the initial time of recording. Anomaly-detection methods are suitable for tumor delineation in dMRI acquisitions, and may further enhance brain-imaging analysis by detection of occult tumor infiltration in glioma patients, which could improve prognostication of disease evolution and tumor treatment strategies.

(1) Background: We investigated the frequency, location, and lesion size of diffusion restrictions (DR) in magnetic resonance imaging (MRI) of asymptomatic patients after diagnostic angiography and assessed risk factors for their occurrence. (2) Methods: We analyzed diffusion-weighted images (DWI) of 344 patients undergoing diagnostic angiographies in a neuroradiologic center. Only asymptomatic patients who received a magnetic resonance imaging (MRI) examination within seven days after the angiography were included. (3) Results: Asymptomatic infarcts on DWI were identified in 17% of the cases after diagnostic angiography. In these 59 patients, a total of 167 lesions were noted. The diameter of the lesions was 1–5 mm in 128 lesions, and 5–10 mm in 39 cases. Dot-shaped diffusion restrictions were found most frequently (n = 163, 97.6%). None of the patients had neurological deficits during or after angiography. Significant correlations were found between the occurrence of lesions and patient age (p < 0.001), history of atherosclerosis (p = 0.014), cerebral infarction (p = 0.026), or coronary heart disease/heart attack (p = 0.027); and the amount of contrast medium used (p = 0.047) and fluoroscopy time (p = 0.033). (4) Conclusions: With an incidence of 17%, we observed a comparatively high risk for asymptomatic cerebral ischemia after diagnostic neuroangiography. Further measures to reduce the risk of silent embolic infarcts and improve the safety of neuroangiography are warranted.

Abstract Epicardial adipose tissue is involved in the pathophysiology of atrial fibrillation (AF). This study aimed to analyze its relevance as a stroke etiology marker. A retrospective study of acute ischemic stroke patients with large vessel occlusion was conducted, periatrial epicardial adipose tissue thickness (pEATT) on admission computed tomography angiography was measured. One hundred and twenty‐one patients with AF‐related stroke and 94 patients with noncardioembolic stroke were included. Patients with AF‐related stroke had increased pEATT. CT‐measured left‐sided pEATT was an independent predictor of AF‐related stroke (adjusted odds ratio per 1 mm increase = 1.27, 95% CI = 1.05–1.53, p = 0.012). pEATT is an independent marker of AF‐related stroke.

Abstract Seizure Related 6 Homolog Like 2 (SEZ6L2) protein has been shown to have implications in neuronal and especially motor function development. In oncology, overexpression of SEZ6L2 serves as a negative prognostic marker in several tumor entities. Recently, few cases of anti-SEZ6L2 antibody mediated cerebellar syndromes were reported. In this article, we present a case of a 70-year-old woman with subacute onset of gait disturbance, dysarthria and limb ataxia. Serum anti-SEZ6L2 antibodies were markedly increased, and further diagnostic workup revealed left sided breast cancer. Neurological symptoms and SEZ6L2 titer significantly improved after curative tumor therapy. This is a very rare and educationally important report of anti-SEZ6L2 autoimmune cerebellar syndrome with a paraneoplastic etiology. Additionally, we performed a review of the current literature for SEZ6L2, focusing on comparing the published cases on autoimmune cerebellar syndrome.

Background and Purpose The Save ChildS Study demonstrated that endovascular thrombectomy (EVT) is a safe treatment option for pediatric stroke patients with large vessel occlusions (LVOs) with high recanalization rates. Our aim was to determine the long-term cost, health consequences and cost-effectiveness of EVT in this patient population. Methods In this retrospective study, a decision-analytic Markov model estimated lifetime costs and quality-adjusted life years (QALYs). Early outcome parameters were based on the entire Save ChildS Study to model the EVT group. As no randomized data exist, the Save ChildS patient subgroup with unsuccessful recanalization was used to model the standard of care group. For modeling of lifetime estimates, pediatric and adult input parameters were obtained from the current literature. The analysis was conducted in a United States setting applying healthcare and societal perspectives. Probabilistic sensitivity analyses were performed. The willingness-to-pay threshold was set to $100,000 per QALY. Results The model results yielded EVT as the dominant (cost-effective as well as cost-saving) strategy for pediatric stroke patients. The incremental effectiveness for the average age of 11.3 years at first stroke in the Save ChildS Study was determined as an additional 4.02 lifetime QALYs, with lifetime cost-savings that amounted to $169,982 from a healthcare perspective and $254,110 when applying a societal perspective. Acceptability rates for EVT were 96.60% and 96.66% for the healthcare and societal perspectives. Conclusions EVT for pediatric stroke patients with LVOs resulted in added QALY and reduced lifetime costs. Based on the available data in the Save ChildS Study, EVT is very likely to be a cost-effective treatment strategy for childhood stroke.

ObjectiveInflammation is increasingly recognized to be involved in the pathophysiology of aneurysmal subarachnoid hemorrhage (aSAH) and may increase the susceptibility to delayed cerebral ischemia (DCI). Macrophage migration inhibitory factor (MIF) has been shown to be elevated in serum and cerebrospinal fluid (CSF) after aSAH. Here, we determined MIF levels in serum, CSF and cerebral microdialysate (MD) at different time-points after aSAH and evaluated their clinical implications.MethodsMIF levels were measured in serum, CSF and MD obtained from 30 aSAH patients during early (EPd1−4), critical (CPd5−15) and late (LPd16−21) phase after hemorrhage. For subgroup analyses, patients were stratified based on demographic and clinical data.ResultsMIF levels in serum increased during CPd5−15 and decreased again during LPd16−21, while CSF levels showed little changes over time. MD levels peaked during EPd1−4, decreased during CPd5−15 and increased again during LPd16−21. Subgroup analyses revealed significantly higher serum levels in patients with aneurysms located in the anterior vs. posterior circulation during CPd5−15 (17.3 [15.1–21.1] vs. 10.0 [8.4–11.5] ng/ml, p = 0.009) and in patients with DCI vs. no DCI during CPd5−15 (17.9 [15.1–22.7] vs. 11.9 [8.9–15.9] ng/ml, p = 0.026) and LPd16−21 (17.4 [11.7–27.9] vs. 11.3 [9.2–12.2] ng/ml, p = 0.021). In addition, MIF levels in MD during CPd5−15 were significantly higher in patients with DCI vs. no DCI (3.6 [1.8–10.7] vs. 0.2 [0.1–0.7] ng/ml, p = 0.026), while CSF levels during the whole observation period were similar in all subgroups.ConclusionOur findings in a small cohort of aSAH patients provide preliminary data on systemic, global cerebral and local cerebral MIF levels after aSAH and their clinical implications.Clinical trial registrationClinicalTrials.gov, identifier: NCT02142166.

Abstract With diffuse infiltrative glioma being increasingly recognized as a systemic brain disorder, the macroscopically apparent tumor lesion is suggested to impact on cerebral functional and structural integrity beyond the apparent lesion site. We investigated resting-state functional connectivity (FC) and diffusion-MRI-based structural connectivity (SC) (comprising edge-weight (EW) and fractional anisotropy (FA)) in isodehydrogenase mutated (IDHmut) and wildtype (IDHwt) patients and healthy controls. SC and FC were determined for whole-brain and the Default-Mode Network (DMN), mean intra- and interhemispheric SC and FC were compared across groups, and partial correlations were analyzed intra- and intermodally. With interhemispheric EW being reduced in both patient groups, IDHwt patients showed FA decreases in the ipsi- and contralesional hemisphere, whereas IDHmut patients revealed FA increases in the contralesional hemisphere. Healthy controls showed strong intramodal connectivity, each within the structural and functional connectome. Patients however showed a loss in structural and reductions in functional connectomic coherence, which appeared to be more pronounced in IDHwt glioma patients. Findings suggest a relative dissociation of structural and functional connectomic coherence in glioma patients at the time of diagnosis, with more structural connectomic aberrations being encountered in IDHwt glioma patients. Connectomic profiling may aid in phenotyping and monitoring prognostically differing tumor types.

ObjectiveWe aimed to describe the magnetic resonance imaging (MRI) characteristics of chronic subdural hematoma (cSDH) and to ascribe MRI patterns.MethodsA total of 20 patients having 27 subdural hematomas underwent contrast-enhanced (CE) MRI of the brain at our institution between April 2019 and May 2021. The images were independently evaluated by two experienced neuroradiologists with regard to imaging characteristics on T1w, T2w, T2*-GRE, FLAIR, diffusion-weighted magnetic resonance imaging (DWI), and CE images.ResultsThe signal characteristics of cSDH on T1- and T2-weighted images were rather heterogeneous. The majority of hematomas (74%) had internal septations. Surprisingly, contrast enhancement along the outer membrane adjacent to the cranium was noticed in all hematomas. There was also contrast enhancement along the inner membrane adjacent to the brain in more than one-third of the hematomas (37%). In approximately two-thirds of the cSDH (62%), there was a mass-like enhancement of the hematoma. Most hematomas (89%) were partially hypointense on T2*-GRE and/or susceptibility-weighted imaging (SWI). Restricted diffusion was detected in approximately one-third of the hematomas (33%).ConclusionConsistent contrast enhancement along the outer membrane, triangular-shaped contrast enhancement at the borders of the cSDH, and infrequent enhancement of the inner membrane may help to distinguish cSDH from other entities such as empyema and tumors. Mass-like enhancement may refer to non-solid hematomas and could be an indicator for hematoma growth and a possible surrogate for successful endovascular embolization. Restricted diffusion in a subdural mass is not specific for empyema but may also be found in cSDH.

Abstract Background The SARS-Coronavirus-2 (SARS-CoV-2) invades the respiratory system, causing acute and sometimes severe pulmonary symptoms, but turned out to also act multisystematically with substantial impact on the brain. A growing number of studies suggests a diverse spectrum of neurological manifestations. To investigate the spectrum of symptoms, we here describe the neurological manifestations and complications of patients with proven SARS-CoV-2 infection who have been hospitalized at the RWTH University Hospital Aachen, Germany. Methods Between March and September 2020, we evaluated common symptoms, clinical characteristics, laboratory (including cerebrospinal fluid (CSF) analysis), radiological, and electroencephalography (EEG) data from 53 patients admitted with a positive SARS-CoV-2 polymerase chain reaction (PCR). We used the Montreal Cognitive Assessment Test (MoCA) to screen for cognitive impairment, when feasible. We compared critically ill and non-critically ill patients categorized according to the presence of Acute Respiratory Distress Syndrome (ARDS). Results Major clinical neurological features of hospitalized COVID-19 patients were coordination deficits (74%), cognitive impairment (61.5%), paresis (47%), abnormal reflex status (45%), sensory abnormalities (45%), general muscle weakness and pain (32%), hyposmia (26%), and headache (21%). Patients with ARDS were more severely affected than non-ADRS patients. 29.6% of patients with ARDS presented with subarachnoid bleedings, and 11.1% showed ischemic stroke associated with SARS-CoV-2 infection. Cognitive deficits mainly affected executive functions, attention, language, and delayed memory recall. We obtained cerebrospinal fluid (CSF) by lumbar puncture in nine of the 53 patients, none of which had a positive SARS-CoV-2 PCR. Conclusions In line with previous findings, our results provide evidence for a range of SARS-CoV-2-associated neurological manifestations. 26% of patients reported hyposmia, emphasizing the neuro-invasive potential of SARS-CoV-2, which can enter the olfactory bulb. It can therefore be speculated that neurological manifestations may be caused by direct invasion of the virus in the CNS; however, PCR did not reveal positive intrathecal SARS-CoV-2. Therefore, we hypothesize it is more likely that the para-infectious severe pro-inflammatory impact of COVID-19 is responsible for the neurological deficits including cognitive impairment. Future studies with comprehensive longitudinal assessment of neurological deficits are required to determine potential long-term complications of COVID-19.

ObjectivesThe primary aim of this study was to conduct a meta-analysis of the literature on interventional treatment for patients with extracranial AVM of the head and neck to identify a superior treatment. The secondary aim was to evaluate the methodological quality of associated articles published between 2000-2020.MethodsThe literature search was conducted on PubMed, Embase, the Cochrane Library, and scholar.google.com. Studies, meeting the acceptable reference standard underwent meta-analysis. All identified literature underwent methodological quality analysis.ResultsOf 1560 screened articles, 56 were included in the literature review. Appropriate diagnostic tests were reported in 98% of included articles. 13% of included articles did not specify the embolization agent. Outcome analysis varied throughout. 45% of the authors used radiographic imaging for follow-up. 77% specified the span of follow-up of their entire patient collective. Two articles met the inclusion criteria for meta-analysis. Curing rate of transarterial ethanol embolization for intraosseous AVM was 83% with a complication rate of 58%. Curing rate of ethanol combined with NBCA or Onyx in soft tissue AVM was 18% with a complication rate of 87%.ConclusionOur literature review revealed an absence of treatment or reporting standards for extracranial AVM of the head and neck. The meta-analysis is comprised of two articles and methodological quality is heterogeneous. We recommend implementing consistent reporting standards to facilitate comparability of studies and to provide robust data for the development of an evidence-based treatment strategy.Advances in knowledgeMeta-analysis showed a favorable radiological outcome for intraosseous AVM when treated with intraarterial ethanol embolization. Our analysis demonstrated that the published data on extracranial AVMs of the head and neck is lacking in consistency and quality, prompting agreement for the need of standardized reporting on AVM treatments.

The branches of the porcine subclavian artery are frequently used in endovascular stroke training and research. This study aimed to determine a porcine weight group, in which the arterial diameters most closely match human cerebral artery diameters, and thus optimize the porcine in-vivo model for neuroendovascular purposes. A group of 42 German Landrace swine (45-74 kg) was divided into four subgroups according to their weight. Angiographic images of the swine were used to determine the arterial diameter of the main branches of the subclavian artery: axillary artery, brachial artery, external thoracic artery, subscapular artery (at two different segments), suprascapular artery, caudal circumflex humeral artery, thoracodorsal artery, and circumflex scapular artery. The porcine arterial diameters were correlated with animal weight and compared to luminal diameters of human arteries which are commonly involved in stroke: internal carotid artery, basilar artery, vertebral artery, middle cerebral artery and M2 branches of the middle cerebral artery. Swine weight was positively correlated with porcine arterial diameter. The most conformity with human arterial diameters was found within the two heavier porcine groups (55-74 kg). We suggest the use of swine with a weight between 55-59.7 kg, as lighter animals show less similarity with human arterial diameters and heavier animals could cause more problems with manipulation and handling.

Knowledge of platelet function in pigs and the effectiveness of antiplatelet therapy is important to ensure proper transferability from animal studies to humans. Our aim was to (1) characterize baseline platelet function of Aachen minipigs using the bedside Multiplate analyzer, (2) compare baseline platelet function with Göttingen minipigs, and (3) characterize platelet inhibition within the first 5 minutes after intravenous administration of acetylsalicylic acid (ASA). We characterized the baseline platelet function and hematological parameters in 9 Aachen minipigs. Historical data of 8 unmedicated Göttingen minipigs were used for comparison of baseline values. Platelet inhibition in Aachen minipigs was tested 1–5 minutes after intravenous administration of 500 mg ASA. Multiplate examinations included the following tests: ASPI test (to assess the effect of ASA), adenosine-diphosphate-test (ADP test) and thrombin receptor activating peptide test (TRAP test). Median values and interquartile range (IQR) of the Multiplate baseline tests in Aachen minipigs were as follows: ASPI: 39 U (IQR = 21–71), ADP: 70 U (IQR = 48–73), and TRAP: 8 U (IQR = 6–9), whereas the values in Göttingen minipigs were as follows: ASPI: 70.5 U (IQR = 60–78), ADP: 51 U (IQR = 45–66), and TRAP: 6.5 U (IQR = 4–8). ASPI values of Göttingen minipigs were significantly higher than those of Aachen minipigs (p = 0.046). Intravenous administration of ASA in Aachen minipigs resulted in significant platelet inhibition after 1 minute, which remained stable over a period of 5 minutes (p≤0.038). Aachen minipigs appeared to have a high variance in arachidonic acid-mediated platelet aggregation. In Aachen minipigs, intravenous ASA administration resulted in immediate platelet inhibition.

In a changing learning environment where young neurointerventionalists spend less time in the operating room, computer simulators have been established as a new training model. Our aim was the comparison of silicone models and computer simulators, and the evaluation of their influence on subjective self-confidence of operators. Pre- and postquestionnaires of 27 participants and 9 tutors were evaluated after the participation in a three-days interventional stroke course using silicone models and computer simulators. Training on computer simulators was considered as more realistic and important before patient contact than training on silicone models. Participants rated their own abilities as significantly better after participation in the course and felt significantly better prepared for patient care. Training on computer simulators can increase the subjective self-confidence of trainees. We suggest a stepwise training program, comprising both ex-vivo and the porcine in-vivo model, finished by conventional operating room teaching, to prepare neuroradiologists for optimal patient care when performing interventions.

ObjectivesThe aim of this study was to demonstrate the efficacy and feasibility of treating patients with extracranial arteriovenous malformations (AVM) of the head and neck with interventional embolization followed by surgical resection.MethodsWe reviewed the charts of all patients between 2012 and 2021 with extracranial AVM of the head and neck scheduled for interdisciplinary treatment according to University Hospital RWTH Aachen's protocol and conducted standardized interviews using a newly developed questionnaire. Interview results, as well as clinical examination and radiographic outcome results were analyzed to help determine the efficacy of our treatment approach.ResultsWe included 10 patients (8 female, 2 male), with a mean age of 33.5 (11-61) years who were scheduled for treatment of the AVM with interventional embolization followed by surgical resection. In 6 of the 10 patients (60%) the lesion was located in extracranial soft tissue only. In one patient (10%), the lesion was located in bone tissue only. A combined intraosseous and oral soft tissue lesion was seen in the remaining 3 patients (30%). Radiographic resolution was achieved in 62.5% of cases and a significant decrease of symptoms was identified (p = 0.002). None of the patients reported dissatisfaction and no major complications occurred.ConclusionAn interdisciplinary treatment approach combining neuroradiological interventions with surgical resection appears to be an effective treatment with an acceptable complication rate. Patients treated according to our protocol showed a high satisfaction rate, regardless of the radiographic outcome. Standardized follow-up allows for early detection of recurrences and helps with subjective patient satisfaction.

Background: The application of a new coating to the delivery wire of the Trevo retriever has the potential to improve its handling. We therefore report our initial experience with this new stent retriever for mechanical thrombectomy of large and medium vessel occlusions.Methods: We pooled data of four high-volume European stroke centers over the time period from October 2020 to February 2021. Patients were included in our study if the Trevo NXT stent retriever was used as a first-line device. Primary endpoints were first-pass near-complete or complete reperfusion, defined as mTICI score of ≥2c. Secondary endpoints were final reperfusion, National Institutes of Health Stroke Scale (NIHSS) at 24 h and discharge, device malfunctions, complications during the procedure, and subjective ratings of the interventionalists regarding device functionality.Results: Eighty patients (39 women, mean age 74 ± 14 years) were eligible for our study. Median NIHSS at admission was 15 (IQR, 8–19), and median Alberta Stroke Program Early CT Score at baseline was 9 (IQR, 8–10). In 74 (93%) patients a primary combined approach was used as first-line technique. First-pass near-complete reperfusion was achieved in 43 (54%) and first-pass complete reperfusion in 34 (43%) patients. Final near-complete reperfusion was achieved in 66 (83%) patients after a median of 1.5 (1–3) passes, while final successful reperfusion was observed in 96% of our cases. We observed no device malfunctions. Median NIHSS at discharge was 2 (IQR, 0–5), and 3 patients (4%) suffered a symptomatic intracranial hemorrhage.Conclusions: Based on our initial data, we conclude that the Trevo NXT is an effective and safe tool for mechanical thrombectomy especially when used for combined approaches.

Objective: Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus.Methods: Static and dynamic RVA were performed using a Retinal Vessel Analyzer (IMEDOS Systems GmbH, Jena) in 70 aSAH patients during the early (d0−4), critical (d5−15), late (d16−23) phase, and at follow-up (f/u > 6 weeks) after the ictus. For comparison, an age-matched cohort of 42 healthy subjects was also included in the study. Vessel diameters were quantified in terms of the central retinal arterial and venous equivalent (CRAE, CRVE) and the retinal arterio-venous-ratio (AVR). Vessel responses to flicker light excitation (FLE) were quantified by recording the maximum arterial and venous dilation (MAD, MVD), the time to 30% and 100% of maximum dilation (tMAD30, tMVD30; tMAD, tMVD, resp.), and the arterial and venous area under the curve (AUCart, AUCven) during the FLE. For subgroup analyses, patients were stratified according to the development of DCI and clinical outcomes after 12 months.Results: Vessel diameter (CRAE, CRVE) was significantly smaller in aSAH patients and showed little change throughout the whole observation period (p < 0.0001 vs. control for all time periods examined). In addition, aSAH patients exhibited impaired arterial but not venous responses to FLE, as reflected in a significantly lower MAD [2.2 (1.0–3.2)% vs. 3.6 (2.6–5.6)% in control subjects, p = 0.0016] and AUCart [21.5 (9.4–35.8)%*s vs. 51.4 (32.5–69.7)%*s in control subjects, p = 0.0001] on d0−4. However, gradual recovery was observed during the first 3 weeks, with close to normal levels at follow-up, when MAD and AUCart amounted to 3.0 [2.0–5.0]% (p = 0.141 vs. control, p = 0.0321 vs. d5−15) and 44.5 [23.2–61.1]%*s (p = 0.138 vs. control, p < 0.01 vs. d0−4 & d5−15). Finally, patients with clinical deterioration (DCI) showed opposite changes in the kinetics of arterial responses during early and late phase, as reflected in a significantly lower tMAD30 on d0−4 [4.0 (3.0–6.8) s vs. 7.0 (5.0–8.0) s in patients without DCI, p = 0.022) and a significantly higher tMAD on d16−23 (24.0 (21.0–29.3) s vs. 18.0 (14.0–21.0) s in patients without DCI, p = 0.017].Conclusion: Our findings confirm and extend previous observations that aSAH results in sustained impairments of NVC in the retina. DCI may be associated with characteristic changes in the kinetics of retinal arterial responses. However, further studies will be required to determine their clinical implications and to assess if they can be used to identify patients at risk of developing DCI.Trial Registration:ClinicalTrials.gov Identifier: NCT04094155.

The treatment of acute ischemic stroke by mechanical thrombectomy has been revolutionary, however most of the clinical trials were done with the use a stent retriever. At the same time, an alternative technique of thrombectomy through direct aspiration with a large bore distal access catheter at the face of the clot is rapidly gaining popularity. Nonetheless, the data supporting this new technique is not yet as mature as that available on stent retrievers. This review is a critical analysis of the evidence supporting the principle of direct aspiration thrombectomy and a discussion of its potential strengths and weaknesses in comparison to the available studies on stent retrievers. While this is by no means a conclusive review, it should serve as a yardstick of where the science is currently, and what are the next trials that are necessary.

IntroductionSince the onset of the coronavirus disease 2019 (COVID-19) pandemic, wearing surgical face masks has become mandatory for healthcare staff in many countries when interacting with patients. Recently, it has been shown that wearing face masks impairs social interaction by diminishing a person's ability to read the emotion of their counterparts, an essential prerequisite to respond adequately in social situations. It is easily conceivable that this may have a tangible negative influence on the communication and relationship between patients and healthcare personnel. We therefore investigated whether it has an effect on how patients perceive healthcare professionals when physicians and nursing staff wear portrait photos with their smiling faces in addition to face masks.MethodsDuring the study period of 16 days, the medical staff of our Department wore surgical face masks at all times during any kind of interaction with patients. In a pseudorandomized order, all members of our staff additionally affixed their portrait photos to their work clothes on 8 of the 16 days. After completion of their visit, 226 patients were interviewed anonymously in a cross-sectional study design using a questionnaire in which they rated the following three items: friendliness of staff, medical quality of treatment, and how well they felt taken care of during treatment in our Department.ResultsOn days, on which staff wore photos, mean scores of the questionnaires were significantly higher than on non-photo days (p = 0.013; mean ± standard deviation = 92.8 ± 11.3 vs. 91.0 ± 12.6; median (range) = 97 (98) vs. 96 (76)). When analyzed separately, the increased scores were only significant for the item friendliness of staff (p = 0.009; mean ± standard deviation = 95.8 ± 6.3 vs. 92.2 ± 11.5; median (range) = 98 (39) vs. 97 (54)).ConclusionOur study suggests that the use of portrait photos with smiling faces has a positive effect on how patients perceive healthcare staff.

Background and purposeDuring a period of 6 months, we provided our entire neuroradiological staff including physicians, radiographers, and researchers with systematic feedback via email on the further clinical course of stroke patients who underwent mechanical thrombectomy. We analyzed the effects of this feedback on work satisfaction, work meaningfulness and valuation of the therapy among our staff.MethodsOur staff completed two self-reported questionnaires before and after the period of six months with systematic feedback.ResultsEmployees with higher work meaningfulness and higher work satisfaction valuated endovascular stroke therapy as more useful (pConclusionsSystematic email feedback does not per se enhance work satisfaction or work meaningfulness among employees. However, receiving feedback is educative for the staff. Evaluating work satisfaction and the perception of treatment may help to identify unexpected issues and may therefore help to find specific measures that increase work satisfaction and motivation.

In the past, the eloquent areas could be deliberately localised by the invasive Wada test. The very rare cases of dissociated crossed speech areas were accidentally found based on the clinical symptomatology. Today functional magnetic resonance imaging (fMRI)-based imaging can be employed to non-invasively localise the eloquent areas in brain tumour patients for therapy planning. A 41-year-old, left-handed man with a low-grade glioma in the left frontal operculum extending to the insular cortex, tension headaches, and anomic aphasia over 5 months underwent a pre-operative speech area localisation fMRI measurement, which revealed the evidence of the transhemispheric disposition, where the dominant Wernicke speech area is located on the left and the Broca’s area is strongly lateralised to the right hemisphere. The outcome of the Wada test and the intraoperative cortico-subcortical stimulation mapping were congruent with this finding. After tumour removal, language area function was fully preserved. Upon the occurrence of brain tumours with a risk of impaired speech function, the rare dissociate crossed speech areas disposition may gain a clinically relevant meaning by allowing for more extended tumour removal. Hence, for its identification, diagnostics which take into account both brain hemispheres, such as fMRI, are recommended.

Immunohistochemical data based on isocitrate–dehydrogenase (IDH) mutation status have redefined glioma as a whole-brain disease, while occult tumor cell invasion along white matter fibers is inapparent in conventional magnetic resonance imaging (MRI). The functional and prognostic impact of focal glioma may however relate to the extent of white matter involvement. We used diffusion tensor imaging (DTI) to investigate microstructural characteristics of whole-brain normal-appearing white matter (NAWM) in relation to cognitive functions as potential surrogates for occult white matter involvement in glioma. Twenty patients (12 IDH-mutated) and 20 individually matched controls were preoperatively examined using DTI combined with a standardized neuropsychological examination. Tumor lesions including perifocal edema were masked, and fractional anisotropy (FA) as well as mean, radial, and axial diffusivity (MD, RD, and AD, respectively) of the remaining whole-brain NAWM were determined by using Tract-Based Spatial Statistics and histogram analyses. The relationship between extratumoral white matter integrity and cognitive performance was examined using partial correlation analyses controlling for age, education, and lesion volumes. In patients, mean FA and AD were decreased as compared to controls, which agrees with the notion of microstructural impairment of NAWM in glioma patients. Patients performed worse in all cognitive domains tested, and higher anisotropy and lower MD and RD values of NAWM were associated with better cognitive performance. In additional analyses, IDH-mutated and IDH-wildtype patients were compared. Patients with IDH-mutation showed higher FA, but lower MD, AD, and RD values as compared to IDH-wildtype patients, suggesting a better preserved microstructural integrity of NAWM, which may relate to a less infiltrative nature of IDH-mutated gliomas. Diffusion-based phenotyping and monitoring microstructural integrity of extratumoral whole-brain NAWM may aid in estimating occult white matter involvement and should be considered as a complementary biomarker in glioma.

Background: The implementation of rescue efforts for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage remains largely empirical for a lack of supporting evidence, while the associated risk profile is also unclear.Objective: The present study evaluates the safety and efficacy of endovascular rescue treatment (ERT, continuous intraarterial nimodipine; IAN, transcutaneous balloon angioplasty, TBA).Methods: In this prospective observational study, we assessed periprocedural complications and side effects in context of ERT. We evaluated neurological status, multimodal neuromonitoring (ptiO2, lactate/pyruvate ratio, transcranial doppler), and cranial imaging (CTP, DSA). All parameters were included into multivariate analysis to determine predictors for the need of retreatment.Results: We included 33 consecutive patients with 54 ERT (IAN n = 35; TBA n = 13; TBA + IAN n = 6). We recorded no serious complications and initial improvement in all parameters (neurostatus 72.3% of patients; ptiO2 15.0 ± 11.7 to 25.8 ± 15.5 mmHg, p < 0.0001; lactate/pyruvate ratio 46.3 ± 27.5 to 31.0 ± 9.7, p

For endovascular research pigs are an established animal model. However, experiences regarding analyses of platelet inhibition in pigs using the Multiplate® Analyzer are limited. The aims of the present study were to investigate if (1) the Multiplate® Analyzer is a suitable method for examination of porcine platelet function using manufacturers' recommendations for human blood, and (2) platelet inhibition can be induced with acetylsalicylic acid (ASA) and clopidogrel in pigs reliably, and if (3) non-responders to one of the drug can be detected. Additionally we examined differences in (4) the effectiveness of ASA between oral administration and intravenous application, and (5) between domestic pigs (German Landrace; GL) and miniature pigs (MP). We investigated platelet function of 36 unmedicated pigs (GL n = 28; MP n = 8). In addition, 32 blood samples taken from medicated pigs (GL n = 15; MP n = 17) were analysed. Platelet inhibition was induced in four different ways: (1) 500 mg ASA intravenously (n = 11), (2) 500 mg ASA intravenously and 450 mg clopidogrel orally (n = 5), (3) 250 mg ASA orally (n = 11), (4) 250 mg ASA orally and 75 mg clopidogrel orally (n = 5). Results of the ASPI and ADP test of the Multiplate® Analyzer subtests in unmedicated and medicated pigs were in a comparable range to results known from humans. Application of ASA decreased the mean values of the ASPI test significantly regardless of the application method. Joined administration of ASA and clopidogrel also decreased the mean values of the ADP test significantly. Both, oral and intravenous administrations of ASA as well as oral administration of clopidogrel effectively inhibited platelet function in pigs. One pig did not respond to clopidogrel. We found no differences between domestic and miniature pigs regarding reference values in unmedicated pigs and the effectiveness of ASA and clopidogrel.

PurposeKnowledge of the collateralization of an occluded vessel is important for the risk-benefit analysis of difficult revascularization maneuvers during mechanical thrombectomy. If the territory behind a clot is well perfused, one could desist from performing a risky thrombectomy maneuver. The arterial pulse pressure curve may serve as an indicator for the collateralization of an occluded target vessel. We investigated the feasibility of arterial pulse measurements with a standard microcatheter.MethodsWe measured the intra-arterial blood pressure proximal and distal to the clot in 40 thrombectomy maneuvers in a porcine stroke model. We used a microcatheter (Trevo Pro 18, Stryker, Kalamazoo, CA, USA), a pressure transducer (MEMSCAP SP844), an AdInstruments Powerlab 16/35 workstation, and LabChart 8 Software (AdInstruments, Dunedin, New Zealand).ResultsMedian arterial blood pressure proximal and distal to the clot was 96.0 mmHg (IQR, 23.8 mmHg) and 47.5 mmHg (IQR, 43.5 mmHg), respectively (p < .001). The median difference between systolic maximum and diastolic minimum proximal and distal to the clot decreased significantly from 1.8 mmHg (IQR, 3.6 mmHg) to 0.0 mmHg (IQR, 0.5 mmHg) (p < .001). There was loss of the curve in 26 of 40 cases and loss of pressure in 23 of 40 cases (p = .008). There was no significant correlation between vessel diameter and either loss of the pulse pressure curve (p = .20) or overall pressure loss (p = .31).ConclusionIt is possible to measure the pulse pressure proximal and distal to the clot with a standard microcatheter used during mechanical thrombectomy.

Feasibility of endovascular stentectomy using a snare over stent-retriever (SOS) technique was evaluated in a silicon flow model and an in vivo swine model. In vitro, stentectomy of different intracranial stents using the SOS technique was feasible in 22 out of 24 (92%) retrieval maneuvers. In vivo, stentectomy was successful in 10 out of 10 procedures (100%). In one case self-limiting vasospasm was observed angiographically as a technique related complication in the animal model. Endovascular stentectomy using the SOS technique is feasible in an experimental setting and may be transferred to a clinical scenario.

Minipigs are frequently used in (neuro-)interventional research. Longitudinal experiments may require repeated vessel access via the femoral artery. Anticoagulation and incompliance of the animals necessitates the use of a vascular closure device (VCD). The effects of the Angio-Seal VCD in minipigs were longitudinally assessed. Minipig (42±8.4 kg body weight) femoral arteries were sealed using the 8F (n = 6) or 6F (n = 7) Angio-Seal VCD. The pre-interventional femoral artery diameter was 5.1±0.4 mm (4.3-5.8 mm). Sealed puncture sites were analysed angiographically as well as by computed tomography angiography (CTA) for a mean period of 14.1±8.0 weeks (1-22 weeks). All animals were constantly treated with acetylsalicylic acid (ASS) (450 mg/d (n = 7) or 100 mg/d (n = 1)) and clopidogrel (75 mg/d (n = 8)). Non-instrumented (n = 2) and arteries sealed using the VCD (n = 2) were examined histologically. No postoperative hemorrhagic complications were observed. Three arteries were occluded after VCD placement (1 animal diagnosed after 4 weeks (8F), 2 animals after 1 week (6F)) and remained so until the end of the experiments after 22, 12 and 4 weeks, respectively. In one artery a 50% stenosis 8 weeks after application of a 6F Angio-Seal was detected. In 69.2% (n = 9) the VCD was applied without complications. Histopathological analysis of the sealed arterial segments showed subtotal obliteration of the vessel lumen, formation of collagenous tissue and partial damage of the internal elastic lamina. The Angio-Seal VCD prevents relevant hemorrhagic complications in minipigs treated with dual platelet inhibition, but is associated with increased vessel occlusion rates.

To the naïve observer, cubist paintings contain geometrical forms in which familiar objects are hardly recognizable, even in the presence of a meaningful title. We used fMRI to test whether a short training session about Cubism would facilitate object recognition in paintings by Picasso, Braque and Gris. Subjects, who had no formal art education, were presented with titled or untitled cubist paintings and scrambled images, and performed object recognition tasks. Relative to the control group, trained subjects recognized more objects in the paintings, their response latencies were significantly shorter, and they showed enhanced activation in the parahippocampal cortex, with a parametric increase in the amplitude of the fMRI signal as a function of the number of recognized objects. Moreover, trained subjects were slower to report not recognizing any familiar objects in the paintings and these longer response latencies were correlated with activation in a fronto-parietal network. These findings suggest that trained subjects adopted a visual search strategy and used contextual associations to perform the tasks. Our study supports the proactive brain framework, according to which the brain uses associations to generate predictions.

We used event-related fMRI to investigate whether recollection- and familiarity-based memory judgments are modulated by the degree of visual similarity between old and new art paintings. Subjects performed a flower detection task, followed by a Remember/Know/New surprise memory test. The old paintings were randomly presented with new paintings, which were either visually similar or visually different. Consistent with our prediction, subjects were significantly faster and more accurate to reject new, visually different paintings than new, visually similar ones. The proportion of false alarms, namely remember and know responses to new paintings, was significantly reduced with decreased visual similarity. The retrieval task evoked activation in multiple visual, parietal and prefrontal regions, within which remember judgments elicited stronger activation than know judgments. New, visually different paintings evoked weaker activation than new, visually similar items in the intraparietal sulcus. Contrasting recollection with familiarity revealed activation predominantly within the precuneus, where the BOLD response elicited by recollection peaked significantly earlier than the BOLD response evoked by familiarity judgments. These findings suggest that successful memory retrieval of pictures is mediated by activation in a distributed cortical network, where memory strength is manifested by differential hemodynamic profiles. Recollection- and familiarity-based memory decisions may therefore reflect strong memories and weak memories, respectively.