Search

Introduction: Brain areas exhibiting negative blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) responses to carbon dioxide (CO 2 ) are thought to suffer from a completely exhausted autoregulatory cerebrovascular reserve capacity and exhibit vascular steal phenomenon. If this assumption is correct, the presence of vascular steal phenomenon should subsequently result in an equal negative fMRI signal response during a motor-task based BOLD-fMRI study (increase in metabolism without an increase in cerebral blood flow due to exhausted reserve capacity) in otherwise functional brain tissue. To investigate this premise, the aim of this study was to further investigate motor-task based BOLD-fMRI signal responses in brain areas exhibiting negative BOLD-CVR., Material and Methods: Seventy-one datasets of patients with cerebrovascular steno-occlusive disease without motor defects, who underwent a CO 2 -calibrated motor task-based BOLD-fMRI study with a fingertapping paradigm and a subsequent BOLD-CVR study with a precisely controlled CO 2 -challenge during the same MRI examination, were included. We compared BOLD-fMRI signal responses in the bilateral pre- and postcentral gyri - i.e. Region of Interest (ROI) with the corresponding BOLD-CVR in this ROI. The ROI was determined using a second level group analysis of the BOLD-fMRI task study of 42 healthy individuals undergoing the same study protocol., Results: An overall decrease in BOLD-CVR was associated with a decrease in BOLD-fMRI signal response within the ROI. For patients exhibiting negative BOLD-CVR, we found both positive and negative motor-task based BOLD-fMRI signal responses., Conclusion: We show that the presence of negative BOLD-CVR responses to CO 2 is associated with heterogeneous motor task-based BOLD-fMRI signal responses, where some patients show -more presumed- negative BOLD-fMRI signal responses, while other patient showed positive BOLD-fMRI signal responses. This finding may indicate that the autoregulatory vasodilatory reserve capacity does not always need to be completely exhausted for vascular steal phenomenon to occur., Competing Interests: Declaration of Competing Interest Dr. Fisher and Dr. Mikulis report that they contributed to the development of an automated end-tidal targeting device, RespirAct™ which is designed, assembled, and made available as a research tool by Thornhill Medical Inc. Thornhill Medical Inc. is a for profit spin-off company from the University Health Network/University of Toronto. Drs. Fisher and Mikulis have equity in Thornhill Medical Inc. The other authors have no conflicts of interest to declare., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The mechanisms of brain arteriovenous malformation (bAVM) development, formation, and progress are still poorly understood. By gaining more knowledge about the molecular signature of bAVM in relation to hemorrhage, we might be able to find biomarkers associated with this serious complication, which can function as a goal for further research and can be a potential target for gene therapy., Aims: To provide a comprehensive overview of the molecular signature of bAVM-related hemorrhage We conducted a systematic review, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, of articles published in Embase, Medline, Cochrane central, Scopus, and Chinese databases (CNKI, Wanfang)., Summary of Review: Our search identified 3944 articles, of which 3108 remained after removal of duplicates. After title, abstract, and full-text screening, 31 articles were included for analysis. The results show an overview of molecular characteristics. Several genetic polymorphisms are identified that increase the risk of bAVM rupture by increasing the expression of certain inflammatory cytokines (interleukin [IL]-6, IL-17A, IL-1β, and tumor necrosis factor-α), NOTCH pathways, matrix metalloproteinase-9, and vascular endothelial growth factor-α., Conclusions: Several molecular factors are associated with the risk of bAVM-related hemorrhage. These factors are associated with increased inflammation on the cellular level and changes in the endothelium leading to instability of the vessel wall. Further investigation of these biomarkers regarding hemorrhage rates, together with their relationship with noninvasive diagnostic methods, should be a goal of future studies to improve the patient specific risk estimation and future treatment options., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Case fatality and poor outcome rates are different between brain arteriovenous malformation-associated intracerebral hemorrhage (bAVM-ICH) and spontaneous intracerebral hemorrhage (SICH). These outcome rates, however, have never been compared in patients who need neurosurgical evacuation of the intracerebral hemorrhage (ICH)., Objective: To compare the short- and long-term functional outcome between surgically treated patients with bAVM-ICH and SICH., Methods: We collected data from surgically treated ICH patients at the Department of Neurosurgery, University Hospital Zurich, from January 2015 to July 2018. We performed logistic regression analysis to compare the functional outcome between groups, adjusting for demographics, admission characteristics, and stroke risk factors., Results: A total of 26 bAVM-ICH and 115 SICH patients were included in the final analysis. Patients with bAVM-ICH were younger and less likely to have hypertension without significant differences in ICH volume, hematoma location, intraventricular hemorrhage, and other stroke risk factors. A significantly better functional outcome rate was seen in bAVM-ICH patients at short- and long-term follow-up. These differences remained significant after adjusting for confounders., Conclusions: patients with a bAVM who need surgical evacuation of an ICH have a more favorable outcome than surgically treated patients with spontaneous ICH, even after correction for confounding factors, such as younger age and less premorbid hypertension., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: The presence of peritumorally impaired blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) has been unequivocally demonstrated in patients with diffuse glioma, and may have value to better identify tumor infiltration zone. Since BOLD-CVR does not measure hemodynamic changes directly, we performed additional MR perfusion studies to better characterize the peritumoral hemodynamic environment., Methods: Seventeen patients with WHO grade III and IV diffuse glioma underwent high resolution advanced hemodynamic MR imaging including BOLD-CVR and MR perfusion. The obtained multiparametric hemodynamic factors (i.e., regional cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), mean transit time (MTT), time-to-peak (TTP) and BOLD-CVR, were analyzed within 10 concentric expanding 3 mm volumes of interest (VOIs) up to 30 mm from the tumor tissue mask., Results: BOLD-CVR impairment was found within the tumor tissue mask and the peritumoral VOIs up to 21 mm as compared to the contralateral flipped CVR analysis (p<0.05). In the affected hemisphere, we observed positive spatial correlations including all VOIs between BOLD-CVR and rCBV values (r=0.27; p<0.001), rCBF (r=0.42; p<0.001) and a negative correlation between BOLD-CVR and TTP (r=-0.47; p<0.001)., Conclusions: Peritumorally impaired BOLD-CVR is associated with concomitant hemodynamic alterations with severity correlating to tumor volume. The distribution of these multiparametric hemodynamic MRI patterns may be considered for future studies characterizing the hemodynamic peritumoral environment, thereby better identifying the extent of tumor infiltration., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The case fatality in aneurysmal subarachnoid hemorrhage (aSAH) is 50% because of the initial hemorrhage or subsequent complications, such as aneurysmal rebleed or delayed cerebral ischemia. One factor that might influence the initial brain damage or subsequent complications is the use of antiplatelet medication before the initial hemorrhage. The goal of this survey was to assess the different management options of patients with aSAH with antiplatelet use before the initial hemorrhage., Methods: An anonymous survey of 11 multiple choice questions about management of patients with aSAH with antiplatelet use before the initial hemorrhage was distributed to the international panel of attendees of the European Association of Neurosurgical Societies annual meeting in Venice, Italy, October 1-5, 2017., Results: A total of 258 completed surveys (54%) were returned. In about 80% of the surveys, the departments of neurosurgery and neurology were responsible for acute management of patients with aSAH, whereas in 15% the intensive care unit was responsible. Department guidelines were present in 32%. In 65%, the responders always stopped the antiplatelet agent at admission, and in 4.3% thrombocytes are always transfused. When a guideline is present, the neurospecialists consider thrombocyte transfusion more often (83% vs. 65%, respectively; P = 0.02)., Conclusions: Our survey among mainly European neurosurgeons shows that there is a significant variability in the management of patients with aSAH who have been using antiplatelets before the initial hemorrhage. These findings emphasize the importance of the development of evidence-based guidelines for management of patients with aSAH and antiplatelet use before the initial hemorrhage., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Patients with neurofibromatosis type 2 and bilateral vestibular schwannoma (VS) are frequently treated surgically for any tumor progression, and often repeated surgery or radiation treatment is even considered. Some VS progression occurs without the development of new clinical symptoms, or it does not progress in size over many years, even in the absence of any specific treatment., Case Description: A 61-year-old male patient with neurofibromatosis type 2 presented with bilateral VS. In a long-term follow-up, both had increased in size but also showed bilateral spontaneous regression during an 11-year follow-up period with a "watch-and-wait" strategy., Conclusions: We emphasize conservative treatment ("watch and wait") in older patients even with long-term tumor progression without significant compression-related clinical symptoms., (Copyright © 2018 Elsevier Inc. All rights reserved.)