Ischemic Brain Lesions Research Articles

Stroke-GFCN: ischemic stroke lesion prediction with a fully convolutional graph network.

The interpretation of image data plays a critical role during acute brain stroke diagnosis, and promptly defining the requirement of a surgical intervention will drastically impact the patient's outcome. However, determining stroke lesions purely from images can be a daunting task. Many studies proposed automatic segmentation methods for brain stroke lesions from medical images in different modalities, though heretofore results do not satisfy the requirements to be clinically reliable. We investigate the segmentation of brain stroke lesions using a geometric deep learning model that takes advantage of the intrinsic interconnected diffusion features in a set of multi-modal inputs consisting of computer tomography (CT) perfusion parameters. We propose a geometric deep learning model for the segmentation of ischemic stroke brain lesions that employs spline convolutions and unpooling/pooling operators on graphs to excerpt graph-structured features in a fully convolutional network architecture. In addition, we seek to understand the underlying principles governing the different components of our model. Accordingly, we structure the experiments in two parts: an evaluation of different architecture hyperparameters and a comparison with state-of-the-art methods. The ablation study shows that deeper layers obtain a higher Dice coefficient score (DCS) of up to 0.3654. Comparing different pooling and unpooling methods shows that the best performing unpooling method is the proportional approach, yet it often smooths the segmentation border. Unpooling achieves segmentation results more adapted to the lesion boundary corroborated with systematic lower values of Hausdorff distance. The model performs at the level of state-of-the-art models without optimized training methods, such as augmentation or patches, with a DCS of . We proposed and evaluated an end-to-end trainable fully convolutional graph network architecture using spline convolutional layers for the ischemic stroke lesion prediction. We propose a model that employs graph-based operations to predict acute stroke brain lesions from CT perfusion parameters. Our results prove the feasibility of using geometric deep learning to solve segmentation problems, and our model shows a better performance than other models evaluated. The proposed model achieves improved metric values for the DCS metric, ranging from 8.61% to 69.05%, compared with other models trained under the same conditions. Next, we compare different pooling and unpooling operations in relation to their segmentation results, and we show that the model can produce segmentation outputs that adapt to irregular segmentation boundaries when using simple heuristic unpooling operations.

A Propensity-Matched Comparison of Ischemic Brain Lesions on Postprocedural MRI in Endovascular versus Open Carotid Artery Reconstruction.

(1) Study purpose: The aim of our prospective single-center, matched case-control study was to compare the number and volume of acute ischemic brain lesions following carotid endarterectomy (CEA) versus carotid artery stenting (CAS) using a propensity-matched design. (2) Methods: Carotid bifurcation plaques were analyzed by using VascuCAP software on CT angiography (CTA) images. The number and volume of acute and chronic ischemic brain lesions were assessed on MRI scans taken 12-48 h after the procedures. Propensity score-based matching was performed at a 1:1 ratio to compare the ischemic lesions on postinterventional MR. (3) Results: A total of 107 patients (CAS, N = 33; CEA, N = 74) were included in the study. There were significant differences in smoking (p = 0.003), total calcification plaque volume (p = 0.004), and lengths of the lesion (p = 0.045) between the CAS and CEA groups. Propensity score matching resulted in 21 matched pairs of patients. Acute ischemic brain lesions were detected in ten patients (47.6%) of the matched CAS group and in three patients (14.2%) in the matched CEA group (p = 0.02). The volume of acute ischemic brain lesions was significantly larger (p = 0.04) in the CAS group than in the CEA group. New ischemic brain lesions were not associated with neurological symptoms in either group. (4) Conclusions: Procedure-related new acute ischemic brain lesions occurred significantly more frequently in the propensity-matched CAS group.

Reactivation of corticogenesis-related transcriptional factors BCL11B and SATB2 after ischemic lesion of the adult mouse brain

The aim of this study was to characterize expression of corticogenesis-related transcription factors BCL11B and SATB2 after brain ischemic lesion in the adult mice, and to analyze their correlation to the subsequent brain recovery. Ischemic brain lesion was induced by transient middle cerebral artery occlusion followed by reperfusion, and the animals with ischemic lesion were compared to the sham controls. Progression of the brain damage and subsequent recovery was longitudinally monitored structurally, by magnetic resonance imaging, and functionally, by neurological deficit assessment. Seven days after the ischemic injury the brains were isolated and analyzed by immunohistochemistry. The results showed higher expression in the brain of both, BCL11B and SATB2 in the animals with ischemic lesion compared to the sham controls. The co-expression of both markers, BCL11B and SATB2, increased in the ischemic brains, as well as the co-expression of BCL11B with the beneficial transcriptional factor ATF3 but not its co-expression with detrimental HDAC2. BCL11B was mainly implicated in the ipsilateral and SATB2 in the contralateral brain hemisphere, and their level in these regions correlated with the functional recovery rate. The results indicate that the reactivation of corticogenesis-related transcription factors BCL11B and SATB2 is beneficial after brain ischemic lesion.

Brain lesions and cognitive decline in patients with atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Swiss National Science Foundation, Swiss Heart Foundation Background In addition to clinical stroke, atrial fibrillation (AF) is associated with a high burden of various vascular brain lesions, the majority of which are silent. However, the impact of these lesions on cognitive performance remains unclear. Purpose Our aim was to assess the association between vascular brain lesions and cognitive decline in clinically asymptomatic AF patients. Methods In a prospective multicentre cohort trial, we included 1536 clinically stable AF patients aged ≥65 years and a limited number of patients aged 45–64 years (90% on oral anticoagulation therapy). Patients underwent brain magnetic resonance imaging (bMRI) for the detection of any brain lesions at baseline (ischemic brain lesions and microbleeds) and yearly cognitive assessment using different standardized tests. Cognitive decline was defined as a measurement >1 standard deviation of the age-education standardized baseline population, compared with individual baseline levels. Multivariable adjusted Cox regression analyses were performed to assess the relationship of baseline brain lesions presence with cognitive decline during follow-up. Results At the time of inclusion, 1030 (67%) of 1536 patients (mean age 72±8 years, 73% male) had one or more vascular brain lesions on baseline MRI. Based on the Montreal Cognitive Assessment score (MoCA), cognitive decline developed in 159 (10%) patients during a mean follow-up of 4.8 years. The incidence rate (per 100 person-years) for cognitive decline (MoCA score) was 3.64 and 1.82 in patients with and without brain lesions, respectively. After multivariable adjustment, the hazard ratio (95% CI) for cognitive decline (MoCA score) was 1.29 (0.85-1.96). The association of brain lesions with cognitive decline was 1.57 (1.02-2.40) for the Digit Symbol Substitution Test (DSST), 1.28 (1.01 to 1.63) for the semantic fluency test (SFT), and 0.91 (0.69-1.21) for the Trail Making Test Part A (TMT-A). Conclusion In our contemporary AF cohort, two thirds of patients had brain lesions on baseline MRI, and these lesions were predictive of worse cognitive outcomes in the mid-term on some of the tests used. The full effects on cognitive outcome will be obtained during even longer follow-up.

C35 A RARE CASE OF NON–BACTERIAL THROMBOTIC ENDOCARDITIS IN YOUNG WOMAN AFFECTED BY ADVANCED UTERINE CANCER

Abstract A 37–year–old woman affected by uterine HPV–related adenocarcinoma complicated by paraneoplastic pulmonary thromboembolism, came to the emergency department for recurrent episodes of dysarthria and blurred vision with spontaneous resolution. Home medications: Enoxaparin 5000 UI b.i.d, levofloxacin 500 mg/die, deltacortene 25 mg/die and omeprazole 20 mg/die. Blood analysis: normocytic anemia (Hb 9 gr/dl),elevated D–dimer (22.5 mcg/ml) and elevated C–reactive protein (18.3 mg/dl). Procalcitonin and blood cultures resulted negative. Brain CT scan: ischemic brain lesions of embolic nature in the right precentral gyrus and in the left post central gyrus. EKG: sinus rhythm, T–wave inversion in inferior leads. In the suspect of cardioembolic stroke a transthoracic (TTE) and subsequent transesophageal (TOE) echocardiography was performed: TTE: isoechoic oval–shaped thickening of the aortic valve cusp tips, producing aortic regurgitation with double jet regurgitation. TOE: evidence of multiple isoechoic masses involving all the aortic cusps, without perivalvular aortic extension, producing significant aortic regurgitation due to coaptation– gap (Figure 1). The diagnosis of non–bacterial thrombotic endocarditis (NBTE) was made up. Although the standard medical therapy (anticoagulation and chemotherapy) was promptly started, it wasn’t effective with progression of the disease leading to surgical indications of valve intervention. The patient underwent aortic valve replacement with bioprosthesis avoiding mechanical prosthesis, despite the young age, in anticipation of major surgery for the uterine cancer. Surgical specimen turned negative for microorganism growth confirming the diagnosis of marantic endocarditis. No further episodes of ischemic stroke appeared after the replacement of the valve and the patient had no neurological sequelae. NBTE is a rare condition of non–infective endocarditis characterized by the formation of aggregates of platelets and fibrin that affects usually undamaged heart valves in the absence of bacteremia and mostly occurs in patients with a predisposing state like hypercoagulability. Surgical indications of valve intervention are not well encoded but in most cases they follow the raccomandations for infective endocarditis. Our experience highlights the need of a prompt intervention in order to reduce the damage of systemic embolization and preserve patient’s hemodynamics with a strict checking of disease progression.

Right-to-Left Shunt in Divers with Neurological Decompression Sickness: A Systematic Review and Meta-Analysis.

The aim of this study was to assess the association between the presence of a right-to-left shunt (RLS) and neurological decompression sickness (NDCS) and asymptomatic brain lesions among otherwise healthy divers. Next to drowning, NDCS is the most severe phenotype of diving-related disease and may cause permanent damage to the brain and spinal cord. Several observational reports have described the presence of an RLS as a significant risk factor for neurological complications in divers, ranging from asymptomatic brain lesions to NDCS. We systematically reviewed the MEDLINE, Embase, and CENTRAL databases from inception until November 2021. A random-effects model was used to compute odds ratios. Nine observational studies consisting of 1830 divers (neurological DCS: 954; healthy divers: 876) were included. RLS was significantly more prevalent in divers with NDCS compared to those without (62.6% vs. 27.3%; odds ratio (OR): 3.83; 95% CI: 2.79-5.27). Regarding RLS size, high-grade RLS was more prevalent in the NDCS group than the no NDCS group (57.8% versus 18.4%; OR: 4.98; 95% CI: 2.86-8.67). Further subgroup analysis revealed a stronger association with the inner ear (OR: 12.13; 95% CI: 8.10-18.17) compared to cerebral (OR: 4.96; 95% CI: 2.43-10.12) and spinal cord (OR: 2.47; 95% CI: 2.74-7.42) DCS. RLS was more prevalent in divers with asymptomatic ischemic brain lesions than those without any lesions (46.0% vs. 38.0%); however, this was not statistically significant (OR: 1.53; 95% CI: 0.80-2.91). RLS, particularly high-grade RLS, is associated with greater risk of NDCS. No statistically significant association between RLS and asymptomatic brain lesions was found.

Association between pouch morphology, cardiovascular risk factors and ischemic brain lesions in patients with left-sided septal pouches

BackgroundLeft atrial outpouching structures such as left atrial diverticula (LADs) and left-sided septal pouches (LSSPs) might be a source of cryptogenic stroke. This imaging study evaluates the association between pouch morphology, patient comorbidities and ischemic brain lesions (IBLs). MethodsThis is a retrospective single-center analysis of 195 patients who received both a cardiac CT and a cerebral MRI. LADs, LSSPs, and IBLs were retrospectively identified. Size measurements included pouch width, length and volume for LADs and circumference, area and volume for LSSPs. The association between LADs/LSSPs, IBLs and cardiovascular comorbidities was determined by univariate and bivariate regression analyses. ResultsThe prevalence and mean volume were 36.4% and 372 ± 569 mm3 for LSSPs, and 40.5% and 415 ± 541 mm3 for LADs. The IBL prevalence was 67.6% in the LSSP group and 48.1% in the LAD group. LSSPs had 2.9-fold increased hazards of IBLs (95%CI: 1.2–7.4, p = 0.024), and LADs showed no significant correlation with IBLs. Size measurements had no impact on IBLs. A co-existing LSSP was associated with an increased prevalence of IBLs in patients with coronary artery disease (HR: 1.5, 95%CI: 1.1–1.9, p = 0.048), heart failure (HR: 3.7, 95%CI: 1.1–14.6, p = 0.032), arterial hypertension (HR: 1.9, 95%CI: 1.1–3.3, p = 0.017), and hyperlipidemia (HR: 2.2, 95%CI: 1.1–4.4, p = 0.018). ConclusionCo-existing LSSPs were associated with IBLs in patients with cardiovascular risk factors, however, pouch morphology did not correlate with the IBL rate. Upon confirmation by further studies, these findings might be considered in the treatment, risk stratification, and stroke prophylaxis of these patients.

Cognitive function restoration in rats with chronic brain ischemia using Semax and hopantenic acid comprehensive administration

The relevance and importance of treating patients with ischemic brain lesions are indisputable. Chronic ischemic processes in the brain occur much more frequently than acute cerebral circulation disorders, leading to prolonged disability and being the main contributors to a significant number of strokes. Cognitive dysfunctions prevail in the dynamics of the post-ischemic period and are often the primary determinants of the severity of residual organic and subsequent functional impairments of the brain. The aim of the study is to investigate the effectiveness of separate and combined administration of Semax and hopantenic acid in the pharmacological correction of cognitive disorders in rats with experimental chronic brain ischemia. It has been established that rats with chronic brain ischemia exhibit cognitive impairments from the 1st day, manifested in worsened learning processes, short-term and long-term memory functioning in the context of conditioned active avoidance and conditioned feeding reflexes. It has been shown that separate and combined application of Semax and hopantenic acid contributes to the restoration of the learning process and improvement of mnestic functions in rats with chronic brain ischemia. The most pronounced nootropic effect in rats with chronic brain ischemia was registered under the conditions of combined administration of Semax and hopantenic acid, starting from the 3rd day of the study. Subsequently, in terms of anti-ischemic efficacy, the effect of Semax follows, which was realized starting from the 3rd day of the study. The least pronounced neuroprotective effect belongs to hopantenic acid, starting from the 7th day of the study. The author considers the obtained data as experimental groundwork for the feasibility of clinically testing the nootropic effects of the combined administration of Semax and hopantenic acid in cases of chronic brain ischemia. The comprehensive pharmacological correction of cognitive disorders in chronic brain ischemia is pathogenetically justified and aimed at activating sanogenetic mechanisms.

The Three Most Discussed Questions in Carotid Artery Surgery. Review of Russian and Foreign Studies in the Last Five Years

This literature review analyzes Russian and foreign publications over the past five years on the three most discussed issues related to carotid artery surgery: 1.Which is more effective: eversion carotid endarterectomy or conventional carotid endarterectomy with patch closure? 2. Which is better: carotid endarterectomy (CEE) or carotid angioplasty and stenting (CAS)? 3. How soon after the development of ischemic stroke should cerebral revascularization be performed? The authors of the article came to the following conclusions: 1. According to the majority of large studies and meta-analyses, conventional CEE with patch closure is associated with a higher risk of internal carotid artery restenosis compared to eversion carotid endarterectomy. Single-center trials with small samples of patients do not find statistical differences between the outcomes of applying both surgical techniques. 2. Large multicenter randomized trials are required to address the effectiveness of CEA and CAS in symptomatic and asymptomatic patients. To date, there has been no consensus on this matter. 3. CEE and CAS can be equally effective and safe in the most acute and acute periods of ischemic stroke when performed in the presence of a mild neurological deficit and the ischemic brain lesion not exceeding 2.5 cm in diameter. Nevertheless, the choice of treatment strategy should be made strictly personalized by a multidisciplinary council based on the experience of the institution and current recommendations.

The Height and Mobility of Protruding Plaque After Carotid Artery Stenting Are Associated with Postoperative Ischemic Lesions.

Tissue protrusion (TP) is a possible cause of cerebral infarction after carotid artery stenting (CAS). Using optical frequency domain imaging (OFDI) and angioscopy, we investigated the relationship between the morphological features of TP and postoperative new ischemic lesions on magnetic resonance imaging (MRI)-diffusion weighted imaging (DWI) after CAS. Fifty patients who underwent CAS and subsequent poststenting intravascular evaluation using both OFDI and angioscopy were included. CAS was performed for proximal protection via the femoral artery approach, and intravascular evaluation with OFDI and angioscopy were performed after stent placement. We compared the background and poststenting intravascular findings between patients with and without postoperative new ischemic lesions on MRI-DWI. TP was observed in 42 patients (84%), and postoperative new ischemic lesions on MRI-DWI were observed in 32 patients (64%). The frequency of TP did not differ between the 2 groups, but the height of TP was higher in the DWI-positive group (0.62mm vs. 0.29mm, P=0.0028), and mobile TP was observed only in the DWI-positive group. The height of TP (P= 0.023) was an independent predictor of new periprocedural ischemic brain lesions after CAS, and its cut-off value for mobility was 0.55mm on the receiver operating characteristic curve (area under the curve, 0.93). The height of TP on OFDI and mobile-TP on angioscopy after CAS were associated with postoperative new ischemic lesions on MRI-DWI. The intravascular evaluation using OFDI and angioscopy could be helpful for a detailed evaluation of TP.

New Diffusion Abnormalities Following Endovascular Treatment for Intracranial Atherosclerosis.

Background There are limited data on new ischemic brain lesions after endovascular treatment for symptomatic intracranial atherosclerotic stenosis (ICAS). Purpose To investigate the (a) characteristics of new ischemic brain lesions at diffusion-weighted MRI (new diffusion abnormalities) after endovascular treatment, (b) characteristics between those treated with balloon angioplasty and stent placement procedures, and (c) predictors of new ischemic brain lesions. Materials and Methods Patients with symptomatic ICAS in whom maximum medical therapy failed were prospectively enrolled between April 2020 and July 2021 from a national stroke center and underwent endovascular treatment. All study participants underwent thin-section diffusion-weighted MRI (voxel size, 1.4 × 1.4 × 2 mm3 with no section gap) before and after treatment. The characteristics of new ischemic brain lesions were recorded. Multivariable logistic regression analysis was performed to determine potential predictors of new ischemic brain lesions. Results A total of 119 study participants (mean age, 59 years ± 11 [SD]; 81 men; 70 treated with balloon angioplasty and 49 with stent placement) were enrolled. Of the 119 participants, 77 (65%) had new ischemic brain lesions. Five of the 119 participants (4%) had symptomatic ischemic stroke. New ischemic brain lesions were located in (61%, 72 of 119) and/or beyond (35%, 41 of 119) the territory of the treated artery. Of the 77 participants with new ischemic brain lesions, 58 (75%) had lesions located in peripheral brain areas. There was no evidence of a difference in the frequency of new ischemic brain lesions between the balloon angioplasty and stent groups (60% vs 71%, P = .20). In adjusted models, cigarette smoking (odds ratio [OR], 3.6; 95% CI: 1.3, 9.7) and more than one operative attempt (OR, 2.9; 95% CI: 1.2, 7.0) were independent predictors of new ischemic brain lesions. Conclusion New ischemic brain lesions on diffusion-weighted MRI scans were common after endovascular treatment for symptomatic intracranial atherosclerotic stenosis, and occurrence may be associated with cigarette smoking and the number of operative attempts. Clinical trial registration no. ChiCTR2100052925 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Russell in this issue.

The impact of anesthetic drugs on hemodynamic parameters and neurological outcomes following temporal middle cerebral artery occlusion in rats.

The induction of ischemic stroke in the experimental model requires general anesthesia. One of the factors that can be effective in the size of ischemic brain lesions and neurological outcomes is the type of anesthesia. So, the current study was designed to compare the impacts of the most important and widely used anesthetics including halothane, isoflurane, and chloral hydrate on the transient middle cerebral artery occlusion (MCAO) outcomes. Adult Male Sprague-Dawley rats were randomly divided into three groups as follows: (1) MCAO + halothane group, (2) MCAO + isoflurane group, and (3) MCAO + chloral hydrate group. After 24 h, the mortality rate, infarct size, tissue swelling, neurological function, hemodynamic, and arterial blood gas parameters were assessed. Our finding showed that 60 min MCAO rats anesthetized with chloral hydrate significantly increased mortality rate, infarct size, tissue swelling, and neurological deficits compared with halothane and isoflurane anesthetics after 24 h of MCAO. Also, chloral hydrate caused a significant decrease in mean arterial pressure and arterial pO2 compared to halothane and isoflurane anesthetics. On the basis of the current data, we concluded that chloral hydrate increased cerebral infarct volume and neurological outcomes and reduced hemodynamic and metabolic parameters compared with halothane and isoflurane-anesthetized rats temporal MCAO.

Clinical and Imaging Phenotypes and Outcomes in a Costa Rican Cohort of Acute Ischemic Stroke Survivors: A Retrospective Study.

We characterized clinical and imaging phenotypes and their association with clinical outcomes in acute ischemic stroke (AIS) survivors in the understudied region of Costa Rica. We conducted a retrospective cohort study in AIS patients treated at a tertiary stroke center in Costa Rica from 2011-2015. Participants underwent detailed phenotyping for cardiovascular risk factors and stroke etiology. We assessed the association of ischemic brain lesion features and clinical outcomes using the Oxfordshire Community Stroke Project (OCSP) classification. We included 684 AIS survivors (60.2% males, aged 68.1 ± 13.6 years, mean ± SD). While the cardiovascular risk profiles and mortality rates of our patients were similar to populations in European and North American countries, only 20.2% of patients with atrial fibrillation (AF) received anticoagulation. On multivariable analysis, patients with total anterior circulation infarct (TACI) displayed an increased risk of complications (OR: 4.2; 95% CI: 2.2-7.8; p < 0.001), higher mortality (OR: 6.9; 95% CI: 2.9-16.1; p < 0.001) and lower chance of functional independence at discharge (OR: 8.9; 95% CI: 4.1-19; p < 0.001) compared to non-TACI. The comorbidity of bronchopneumonia increased the probability of death by 14.5 times. Our observations in a Costa Rican cohort of AIS survivors might help improve local measures for preventing and managing AIS.

Brain endothelial CXCL12 attracts protective natural killer cells during ischemic stroke

BackgroundThe innate lymphoid cell (ILC) family consists of NK cells, ILC type 1, 2, 3 and lymphoid tissue inducer cells. They have been shown to play important roles in homeostasis and immune responses and are generally considered tissue resident. Not much is known about the presence of ILC members within the central nervous system and whether they are tissue resident in this organ too. Therefore, we studied the presence of all ILC members within the central nervous system and after ischemic brain insult.MethodsWe used the photothrombotic ischemic lesion method to induce ischemic lesions within the mouse brain. Using whole-mount immunofluorescence imaging, we established that the ILCs were present at the rim of the lesion. We quantified the increase of all ILC members at different time-points after the ischemic lesion induction by flow cytometry. Their migration route via chemokine CXCL12 was studied by using different genetic mouse models, in which we induced deletion of Cxcl12 within the blood–brain barrier endothelium, or its receptor, Cxcr4, in the ILCs. The functional role of the ILCs was subsequently established using the beam-walk sensorimotor test.ResultsHere, we report that ILCs are not resident within the mouse brain parenchyma during steady-state conditions, but are attracted towards the ischemic stroke. Specifically, we identify NK cells, ILC1s, ILC2s and ILC3s within the lesion, the highest influx being observed for NK cells and ILC1s. We further show that CXCL12 expressed at the blood–brain barrier is essential for NK cells and NKp46+ ILC3s to migrate toward the lesion. Complementary, Cxcr4-deficiency in NK cells prevents NK cells from entering the infarct area. Lack of NK cell migration results in a higher neurological deficit in the beam-walk sensorimotor test.ConclusionsThis study establishes the lack of ILCs in the mouse central nervous system at steady-state and their migration towards an ischemic brain lesion. Our data show a role for blood–brain barrier-derived CXCL12 in attracting protective NK cells to ischemic brain lesions and identifies a new CXCL12/CXCR4-mediated component of the innate immune response to stroke.

Brain segmentation in patients with perinatal arterial ischemic stroke

BackgroundPerinatal arterial ischemic stroke (PAIS) is associated with adverse neurological outcomes. Quantification of ischemic lesions and consequent brain development in newborn infants relies on labor-intensive manual assessment of brain tissues and ischemic lesions. Hence, we propose an automatic method utilizing convolutional neural networks (CNNs) to segment brain tissues and ischemic lesions in MRI scans of infants suffering from PAIS. Materials and MethodsThis single-center retrospective study included 115 patients with PAIS that underwent MRI after the stroke onset (baseline) and after three months (follow-up). Nine baseline and 12 follow-up MRI scans were manually annotated to provide reference segmentations (white matter, gray matter, basal ganglia and thalami, brainstem, ventricles, extra-ventricular cerebrospinal fluid, and cerebellum, and additionally on the baseline scans the ischemic lesions). Two CNNs were trained to perform automatic segmentation on the baseline and follow-up MRIs, respectively. Automatic segmentations were quantitatively evaluated using the Dice coefficient (DC) and the mean surface distance (MSD). Volumetric agreement between segmentations that were manually and automatically obtained was computed. Moreover, the scan quality and automatic segmentations were qualitatively evaluated in a larger set of MRIs without manual annotation by two experts. In addition, the scan quality was qualitatively evaluated in these scans to establish its impact on the automatic segmentation performance. ResultsAutomatic brain tissue segmentation led to a DC and MSD between 0.78–0.92 and 0.18–1.08 mm for baseline, and between 0.88–0.95 and 0.10–0.58 mm for follow-up scans, respectively. For the ischemic lesions at baseline the DC and MSD were between 0.72–0.86 and 1.23–2.18 mm, respectively. Volumetric measurements indicated limited oversegmentation of the extra-ventricular cerebrospinal fluid in both the follow-up and baseline scans, oversegmentation of the ischemic lesions in the left hemisphere, and undersegmentation of the ischemic lesions in the right hemisphere. In scans without imaging artifacts, brain tissue segmentation was graded as excellent in more than 85% and 91% of cases, respectively for the baseline and follow-up scans. For the ischemic lesions at baseline, this was in 61% of cases. ConclusionsAutomatic segmentation of brain tissue and ischemic lesions in MRI scans of patients with PAIS is feasible. The method may allow evaluation of the brain development and efficacy of treatment in large datasets.

The profile of cognitive impairment and hemodynamic compromise in moyamoya: a single-center prospective cohort study.

Patients with moyamoya vasculopathy often experience cognitive impairments. In this prospective single-center study, the authors investigated the profile of neurocognitive impairment and its relation with the severity of ischemic brain lesions and hemodynamic compromise. Patients treated in a Dutch tertiary referral center were prospectively included. All patients underwent standardized neuropsychological evaluation, MRI, digital subtraction angiography, and [15O]H2O-PET (to measure cerebrovascular reactivity [CVR]). The authors determined z-scores for 7 cognitive domains and the proportion of patients with cognitive impairment (z-score < -1.5 SD in at least one domain). The authors explored associations between patient characteristics, imaging and CVR findings, and cognitive scores per domain by using multivariable linear regression and Bayesian regression analysis. A total of 40 patients (22 children; 75% females) were included. The median age for children was 9 years (range 1-16 years); for adults it was 39 years (range 19-53 years). Thirty patients (75%) had an infarction, and 31 patients (78%) had impaired CVR (steal phenomenon). Six of 7 cognitive domains scored below the population norm. Twenty-nine patients (73%) had cognitive impairment. Adults performed better than children in the cognitive domain visuospatial functioning (p = 0.033, Bayes factor = 4.0), and children performed better in processing speed (p = 0.041, Bayes factor = 3.5). The authors did not find an association between infarction, white matter disease, or CVR and cognitive domains. In this Western cohort, cognitive functioning in patients with moyamoya vasculopathy was below the population norm, and 73% had cognitive impairment in at least one domain. The cognitive profile differed between adults and children. The authors could not find an association with imaging findings.

A single-center pilot randomized controlled trial of atorvastatin loading for preventing ischemic brain damage after carotid artery stenting.

Carotid artery stenting (CAS) performed perioperatively with high-dose atorvastatin may reduce the incidence of new ischemic brain lesions, but more high-level evidence is needed. Furthermore, the optimal dose and course of perioperative statin therapy remain uncertain. A single-center, prospective, parallel controlled, pilot randomized clinical trial was conducted at Beijing Hospital. The study includes a total of 130 patients with CAS. The patients were randomly assigned to receive a high-dose of 80 mg/day atorvastatin (n = 65) or a standard-dose of 20 mg/day atorvastatin (n = 65) 3 days before and 3 days after planned CAS. The primary endpoint event was the cumulative incidence of silent new ischemic cerebral lesions (sNICL) on post-CAS cerebral diffusion-weighted magnetic resonance imaging (DW-MRI), transient ischemic attack (TIA), or ischemic stroke within 30 days after CAS. Among the 130 patients, 123 completed the study, of which 63 were in the high-dose group and 60 were in the standard-dose group. The incidence of major endpoint events was 69.8% (44 cases) and 78.3% (46 cases) in the high-dose and standard-dose groups, respectively. There was no significant difference between the two groups (HR, 0.705; 95% CI, 0.315-1.576; p = 0.393). According to the stratified analysis results, the sNICL incidence was significantly different between the two groups in the symptomatic patients (HR, 0.263; 95% CI, 0.70-0.984; p = 0.04). Among patients with CAS, a periprocedural high-dose of atorvastatin did not reduce the rate of periprocedural ischemic brain damage. However, high-dose statins can reduce the incidence of sNICL after CAS in patients with symptomatic carotid stenosis. Clinicaltrials.gov, identifier NCT03079115.

Abstract 9865: Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE Cardiolink-3 Randomized Trial

Introduction: Our objective was to investigate the frequency and distribution of new ischemic brain lesions detected by diffusion-weighted imaging (DWI) on brain MRI after aortic arch surgery. Methods: This was an imaging sub-analysis of the ACE CardioLink-3 randomized controlled trial which compared the safety and efficacy of innominate vs axillary artery cannulation during elective proximal aortic arch surgery. All participants in the trial underwent pre- and post-operative MRI. New ischemic lesions were defined as lesions on post-operative DWI that were not visible on the pre-operative DWI. Results: Of 102 patients who underwent surgery, 71 (70%) had new ischemic lesions on DWI and the total lesion number across all participants was 391. The average lesion number in patients with at least one ischemic lesion was 5.5±4.9, and were similar in the right (3.3±2.7) or left (3.6±2.8) hemispheres (p=0.49). The most common lesion patterns were single or multiple cortical infarcts. Half of the lesions (n=183, 47%) were in the middle cerebral artery territory, while 24% were in the infratentorium. 42% of patients had lesions distributed in both anterior and posterior circulation, 21% in anterior circulation only, and 7% in posterior circulation only. Besides, 20% had lesions in watershed areas. There were no differences in distribution between patients in the innominate vs axillary artery cannulation groups. In multivariable regression models, more severe white matter hyperintensity on pre-operative MRI (odds ratio per 1-score increase of Fazekas scale 1.80; p=0.02) and lower nadir temperature during operation (odds ratio per 1°C decrease, 1.14; p=0.05) were associated with having any new ischemic lesion, while older age (risk ratio per 1-year increase 1.02; p=0.03) and lower nadir temperature (risk ratio per 1°C decrease, 1.06; p=0.06) were associated with higher lesion numbers. Conclusion: In patients who underwent elective proximal aortic arch surgery, new ischemic brain lesions were common, and mostly identified as scattered cortical infarcts in the middle cerebral artery territory. Advanced age, underlying small vessel disease, and lower nadir temperature during operation were risk factors of presence and burden of new ischemic lesions after surgery.

Acute Infarcts on Brain MRI Following Aortic Arch Repair With Circulatory Arrest: Insights From the ACE CardioLink-3 Randomized Trial.

to investigate the frequency and distribution of new ischemic brain lesions detected by diffusion-weighted imaging on brain magnetic resonance imaging after aortic arch surgery. This preplanned secondary analysis of the randomized, controlled ACE (Aortic Surgery Cerebral Protection Evaluation) CardioLink-3 trial compared the safety and efficacy of innominate versus axillary artery cannulation during elective proximal aortic arch surgery. Participants underwent pre and postoperative magnetic resonance imaging. New ischemic lesions were defined as lesions visible on postoperative, but not preoperative diffusion weighted imaging. Of the 111 trial participants, 102 had complete magnetic resonance imaging data. A total of 391 new ischemic lesions were observed on diffusion-weighted imaging in 71 (70%) patients. The average number of lesions in patients with ischemic lesion were 5.5±4.9 with comparable numbers in the right (2.9±2.0) and left (3.0±2.3) hemispheres (P=0.49). Half the new lesions were in the middle cerebral artery territory; 63% of the cohort had ischemic lesions in the anterior circulation, 49% in the posterior circulation, 42% in both, and 20% in watershed areas. A probability mask of all diffusion-weighted imaging lesions revealed that the cerebellum was commonly involved. More severe white matter hyperintensity on preoperative magnetic resonance imaging (odds ratio, 1.80 [95% CI, 1.10-2.95]; P=0.02) and lower nadir nasopharyngeal temperature during surgery (odds ratio per 1°C decrease, 1.15 [95% CI, 1.00-1.32]; P=0.05) were associated with the presentation of new ischemic lesion; older age (risk ratio per 1-year increase, 1.02 [95% CI, 1.00-1.04]; P=0.03) and lower nadir temperature (risk ratio per 1°C decrease, 1.06 [95% CI, 1.00-1.14]; P=0.06) were associated with greater number of lesions. In patients who underwent elective proximal aortic arch surgery, new ischemic brain lesions were common, and predominantly involved the middle cerebral artery territory or cerebellum. Underlying small vessel disease, lower temperature nadir during surgery, and advanced age were risk factors for perioperative ischemic lesions. URL: https://www. gov; Unique identifier: NCT02554032.

Predictors and neurological consequences of periprocedural cerebrovascular events following transcatheter aortic valve implantation with self-expanding valves.

AimsTo evaluate the patient- and procedure-related predictors of transcatheter aortic-valve implantation (TAVI)-associated ischemic brain lesions and to assess the effect of silent cerebral ischemic lesions (SCIL) on neurocognitive function.Methods and resultsWe investigated 113 consecutive patients with severe aortic stenosis who underwent brain magnetic resonance imaging (MRI) within a week following TAVI. To assess periprocedural cerebral ischemic lesions, diffusion-weighted MRI was utilized. We used multivariate linear regression to identify the independent predictors of TAVI-related ischemic lesion volume (ILV) and periprocedural stroke. Neurocognitive evaluation was performed before and following TAVI at 6-month and one-year follow-up. Following TAVI, a total of 944 new cerebral ischemic lesions were detected in 104 patients (92%). The median ILV was 257 μl (interquartile range [IQR]:97.1–718.8μl) with a median lesion number of 6/patient [IQR:2–10]. The majority of ischemic lesions were clinically silent (95%), while 5% of the lesions induced a stroke, which was confirmed by MRI. Predilatation (β = 1.13[95%CI:0.32–1.93], p = 0.01) and the number of valve positioning attempts during implantation (β = 0.28[95%CI:0.06–0.50], p = 0.02) increased the log-transformed total ILV. Predilatation (OR = 12.04[95%CI:1.46–99.07], p = 0.02) and alternative access routes (OR = 7.84[95%CI:1.01–61.07], p = 0.02) were associated with stroke after adjustments for comorbidities and periprocedural factors. The presence of SCILs were not associated with a change in neurocognitive function that remained stable during the one-year follow-up.ConclusionWhile periprocedural ischemic lesions are frequent, most of them are clinically silent and might not impact the patients' neurocognitive function. The number of valve positioning attempts, predilatation, and alternative access routes should be taken into consideration during TAVI to reduce the ILV and risk for stroke.