Pathomechanisms Behind Cognitive Disorders Following Ruptured Anterior Communicating Aneurysms: A Diffusion Tensor Imaging Study

International audienceIntroductionAfter the rupture of anterior communicating aneurysms, most patients experience debilitating cognitive disorders; and sometimes even without showing morphological anomaly on MRI examinations. Diffusion Tensor Imaging (DTI) may help understanding the pathomechanisms leading to such disorders in this subset of patients.MethodsAfter independent assessment, we constituted a population of patients with normal morphological imaging (ACOM group). Then, a case-control study comparing volumetric and voxel-based DTI parameters between the ACOM group and a control population was performed. All patients underwent the full imaging and neuropsychological assessments at 6 months after the aneurysm rupture. Results were considered significant when p<2.02.10−4.ResultsTwelve patients were included in the ACOM group: 75% had at least one disabled cognitive domain. Significant differences in DTI parameters of global white matter were noted (average Fractional Anisotropy: 0.915 [±0.05] in ACOM group versus 0.943 (±0.03); p=1.10−5) and in frontal white matter tracts (superior fronto-occipital fasciculus and anterior parts of the corona radiata) as well as in the fornix.ConclusionCognitive disorders are under-estimated, and DTI confirmed that, even when conventional MRI examinations were normal, there were still signs of diffuse neuronal injuries that seemed to dominate in frontal areas, close to the site of rupture

Predictive score for complete occlusion of intracranial aneurysms treated by flow-diverter stents using machine learning

International audienceBackground: Complete occlusion of an intracranial aneurysm (IA) after the deployment of a flow-diverter stent is currently unpredictable. The aim of this study was to develop a predictive occlusion score based on pretreatment clinical and angiographic criteria.Methods: Consecutive patients with ≥6 months follow-up were included from 2008 to 2019 and retrospectively analyzed. Each IA was evaluated using the Raymond-Roy occlusion classification (RROC) and dichotomized as occluded (A) or residual (B/C); 80% of patients were randomly assigned to the training sample. Feature selection and binary outcome prediction relied on logistic regression and threshold maximizing class separation selected by a CART tree algorithm. The feature selection was addressed by a genetic algorithm selected from the 30 pretreatment available variables.Results: The study included 146 patients with 154 IAs. Feature selection yielded a combination of six variables with a good cross-validated accuracy on the test sample, a combination we labeled DIANES score (IA diameter, indication, parent artery diameter ratio, neck ratio, side-branch artery, and sex). A score of more than -6 maximized the ability to predict RROC=A with sensitivity of 87% (95% CI 79% to 95%) and specificity of 82% (95% CI 64% to 96%) in the training sample. Accuracy was 86% (95% CI 79% to 94%). In the test sample, sensitivity and specificity were 89% (95% CI 77% to 98%) and 60% (95% CI 33% to 86%), respectively. Accuracy was 81% (95% CI 69% to 91%).Conclusion: A score was developed as a grading scale for prediction of the final occlusion status of IAs treated with a flow-diverter stent

Benefits from Exclusion Treatment of Unruptured Brain Arteriovenous Malformations on Epilepsy in Adults

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Video_1_The human placenta as a model for training and research in mechanical thrombectomy: Clarifications and use of the chorionic plate veins.AVI

Indications for mechanical thrombectomy in acute ischemic stroke are increasing, resulting in the continuous development of new devices and techniques. Therefore, there is a need for a realistic testing and training environment that offers the opportunity to practice different procedures and test the latest devices. Some authors have described the use of the human placenta as a model for neurointerventional surgery, with striking similarities to real-life conditions. This model has many advantages, including its relatively low cost and minimal infrastructure requirements, with fewer ethical concerns compared to animal models. So far, some preparation and set-up details were missing, and only arteries from the chorionic plate were used. This article provides the necessary clarifications and a mapping of the chorionic plate veins, so that the use of this model, which is particularly well suited for mechanical thrombectomy, can be as easy and wide as possible. A video explaining how to prepare the model is provided.</p

“Adaptative endovascular strategy to the CloT MRI in large intracranial vessel occlusion” (VECTOR): Study protocol of a randomized control trial

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Visual assessment of diffusion weighted imaging infarct volume lacks accuracy and reliability

International audiencePurpose The DAWN trial (Diffusion weighted imaging or CT perfusion Assessment with clinical mismatch in the triage of Wake-up and late presenting strokes undergoing Neurointervention with Trevo) has demonstrated the benefits of thrombectomy in patients with unknown or late onset strokes, using automated software (RAPID) for measurement of infarct volume. Because RAPID is not available in all centers, we aimed to assess the accuracy and repeatability of visual infarct volume estimation by clinicians and the consequences for thrombectomy decisions based on the DAWN criteria. Materials and methods 18 physicians, who routinely depend on MRI for acute stroke imaging, assessed 32 MR scans selected from a prospective databaseover two independent sessions. Raters were asked to visually estimate the diffusion weighted imaging (DWI) infarct volume for each case. Sensitivity, specificity, and accuracy of the estimated volumes were compared with the available RAPID measurements for various volume cut-off points. Thrombectomy decisions based on DAWN criteria with RAPID measurements and raters’ visual estimates were compared. Inter-rater and intra-rater agreement was measured using kappa statistics. Results The mean accuracy of raters was <90% for all volume cut-points. Inter-rater agreement was below substantial for each DWI infarct volume cut-off points. Intra-rater agreement was substantial for 55–83% of raters, depending on the selected cut-off points. Applying DAWN criteria with visual estimates instead of RAPID measurements led to 19% erroneous thrombectomy decisions, and showed a lack of reproducibility. Conclusion The visual assessment of DWI infarct volume lacks accuracy and repeatability, and could lead to a significant number of erroneous decisions when applying the DAWN criteria

Benefit of mechanical thrombectomy in acute ischemic stroke related to calcified cerebral embolus

International audienceMechanical thrombectomies (MT) in patients with large vessel occlusion (LVO) related to calcified cerebral embolus (CCE) have been reported, through small case series, being associated with low reperfusion rate and worse outcome, compared to regular MT. The purpose of the MASC (Mechanical Thrombectomy in Acute Ischemic Stroke Related to Calcified Cerebral Embolus) study was to evaluate the incidence of CCEs treated by MT and the effectiveness of MT in this indication

sj-docx-1-wso-10.1177_17474930231205213 – Supplemental material for Evaluation of mechanical thrombectomy in acute ischemic stroke related to a distal arterial occlusion: A randomized controlled trial

Supplemental material, sj-docx-1-wso-10.1177_17474930231205213 for Evaluation of mechanical thrombectomy in acute ischemic stroke related to a distal arterial occlusion: A randomized controlled trial by Frédéric Clarençon, Isabelle Durand-Zaleski, Kévin Premat, Amandine Baptiste, Emmanuel Chabert, Anna Ferrier, Marc-Antoine Labeyrie, Peggy Reiner, Laurent Spelle, Christian Denier, Titien Tuilier, Hassan Hosseini, Christine Rodriguez-Régent, Guillaume Turc, Cédric Fauché, Matthias Lamy, Bertrand Lapergue, Arturo Consoli, Charlotte Barbier, Marion Boulanger, Nicolas Bricout, Hilde Henon, Benjamin Gory, Sébastien Richard, Aymeric Rouchaud, Francisco Macian-Montoro, Omer Eker, Tae-Hee Cho, Sébastien Soize, Solène Moulin, Jean-Christophe Gentric, Serge Timsit, Jean Darcourt, Jean-François Albucher, Kévin Janot, Mariam Annan, Fernando Pico, Vincent Costalat, Caroline Arquizan, Gautier Marnat, Igor Sibon, Raoul Pop, Valérie Wolff, Eimad Shotar, Stéphanie Lenck, Nader-Antoine Sourour, Anne Radenne, Sonia Alamowitch and Agnès Dechartres in International Journal of Stroke</p