The latest medical research on Cerebrovascular & Skull Base Surgery

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about cerebrovascular & skull base surgery gathered by our medical AI research bot.

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Differentiation of Fibroblasts Into Myofibroblasts in the Arachnoid Membrane of Moyamoya Disease.

Stroke

Moyamoya disease (MMD) is a very specific disorder in terms of spontaneous development of extracranial-to-intracranial collateral circulation through the dura mater, but the underlying mechanisms are unclear. This study aimed to investigate the role of the arachnoid membrane in this unique angiogenesis in MMD.

A piece of arachnoid membrane and 1- to 2-mL cerebrospinal fluid were simultaneously harvested during surgery from 26 patients with MMD. The specimens were also collected during surgery as the controls from 6 patients with atherosclerotic carotid artery diseases. The arachnoid membrane was subjected to immunohistochemistry and the cerebrospinal fluid was used to measure the concentration of cytokines using ELISA.

The number of cells positive for PDGFR (platelet-derived growth factor receptor) α was significantly higher in MMD than in the controls (5.4±3.1 versus 2.3±2.1 cells/field; P=0.02). The results were same in PDGFRβ-positive cells (10.1±4.6 versus 4.8±2.8; P=0.01) and α-SMA (alpha-smooth muscle actin)-positive cells (8.8±3.1 versus 2.0±2.5; P<0.01). On multicolor immunofluorescence, 80.5±15.6% of cells positive for PDGFRα in MMD also expressed α-SMA, being significantly higher than 14.6±7.2% in the controls (P<0.01). The density of collagen in the arachnoid membrane was significantly higher in MMD than in the controls (60.3±15.0% versus 40.1±15.3%; P<0.01). In MMD, advanced disease stage was significantly associated with a larger number of α-SMA-positive cells in the arachnoid membrane (P=0.04). On ELISA, the cerebrospinal fluid concentrations of bFGF (basic fibroblast growth factor), HGF (hepatocyte growth factor), and TGF (transforming growth factor)-β1 were significantly higher in MMD than in the controls.

Based on these findings, MMD may elevate the concentrations of angiogenic factors in the cerebrospinal fluid and then promote the proliferation of fibroblasts in the arachnoid membrane and their differentiation into myofibroblasts, which may, in turn, enhance the production of collagen essential for spontaneous collateral formation across the arachnoid membrane.

Tuberculosis and Risk of Ischemic Stroke: A Nationwide Cohort Study.

Stroke

Conflicting results exist regarding the risk of ischemic stroke in tuberculosis survivors. We aimed to estimate the risk of ischemic stroke using a nationwide population-based retrospective cohort.

We gathered data from the Korean National Health Insurance Service on tuberculosis survivors and 1:1 age- and sex-matched non-tuberculosis cases. Eligible participants were followed up from 1 year after tuberculosis diagnosis to the date of ischemic stroke event, date of death, or until the end of the study period (December 31, 2018), whichever came first. Cox proportional hazard regression and stratified analyses were performed to identify any related factors.

During follow-up periods of 3.8 years for patients with tuberculosis and matched non-tuberculosis cases, 1.3% of patients with tuberculosis (941/72 863) and 1.0% of matched non-tuberculosis cases (707/72 863) developed ischemic stroke. The overall risk of ischemic stroke was higher in tuberculosis patients (adjusted hazard ratio: 1.22 [95% CI, 1.10-1.36]) compared with the matched non-tuberculosis cases. A stratified analysis showed that patients with tuberculosis had increased risk of ischemic stroke regardless of age, sex, smoking status, alcohol consumption, physical activity, body mass index, and Charlson Comorbidity Index score.

Tuberculosis survivors had a higher risk of ischemic stroke than their matched non-tuberculosis cases. The results of this study suggest that tuberculosis is a crucial infectious factor associated with increased incidence of ischemic stroke.

Fibrinogen Depletion Coagulopathy Predicts Major Bleeding After Thrombolysis for Ischemic Stroke: A Multicenter Study.

Stroke

Symptomatic intracerebral hemorrhage (sICH) and major bleeding can be fatal complications of intravenous thrombolysis (IVT) for acute ischemic stroke. We investigated the impact of early fibrinogen depletion after IVT on major bleeding events.

This multicenter observational prospective cohort study enrolled 1678 consecutive patients receiving IVT for acute ischemic stroke at 6 Italian centers, undergoing fibrinogen concentration assessment at baseline, 2 hours and 6 hours after IVT. Fibrinogen depletion was defined as a reduction below 200 mg/dL after 2 hours from IVT, or as a reduction below 50% of baseline fibrinogen levels after 2 hours from IVT. Main outcomes were (1) sICH (National Institute of Neurological Disorders and Stroke criteria) and (2) major bleeding defined as fatal bleeding, decrease in the hemoglobin level>2 g/dL/>1 unit transfusion, or bleeding at critical site. Additional outcomes were (1) any ICH, (2) any bleeding, (3) fatal ICH, and (4) sICH according to ECASSII definition. Good functional recovery was defined as modified Rankin Scale score 0 to 2 at 3 months.

Overall, 1678 patients were included (mean age 72 years, 46% female). sICH (n=116) and major bleeding (n=297) were associated with lower rate of good functional recovery (P<0.001). Despite similar fibrinogen levels at admission, fibrinogen depletion after 2 hours from IVT was more common in people with sICH, major bleeding and all additional bleeding outcomes. In the backward stepwise multivariable logistic regression model, fibrinogen depletion remained a significant predictor of sICH (OR, 1.55 [95% CI, 1.04-2.32]) and major bleeding (OR, 1.36 [95% CI, 1.03-1.8]). Thirty-one percent of sICH could be attributable to fibrinogen depletion. The association between fibrinogen depletion and worse clinical outcome at 3 months after stroke (P=0.012) was attributable to the higher risk of major bleeding/sICH.

Fibrinogen depletion significantly increases the risk of sICH and major bleeding after IVT for acute ischemic stroke. Fibrinogen depletion represents an independent risk factor for bleeding, and routine assessment could be considered to stratify the risk of ICH. Trials on early fibrinogen repletion are needed to investigate mitigation of bleeding risk.

Quantifying Improved Outcomes, Cost Savings, and Hospital Volume Changes From Optimized Emergency Stroke Transport.

Stroke

A previously published conditional probability model optimizes prehospital emergency transport protocols for patients with suspected large-vessel occlusion by recommending the transport strategy, drip-and-ship or mothership, that results in a higher probability of an excellent outcome. In this study, we create generalized models to quantify the change in annual hospital patient volume, the expected annual increase in the number of patients with an excellent outcome, and the annual cost savings to a single-payer healthcare system resulting from these optimized transport protocols.

We calculated the expected number of patients with suspected large-vessel occlusion transported by ambulance over a 1-year period in a region of interest, using the annual stroke incidence rate and a large-vessel occlusion screening tool. Assuming transport to the closest hospital is the baseline transport policy across the region (drip-and-ship), we determined the change in annual hospital patient volume from implementing optimized transport protocols. We also calculated the resulting annual increase in the number of patients with an excellent outcome (modified Rankin Score of 0-1 at 90 days) and associated cost savings to a single-payer healthcare system. We then performed a case study applying these generalized models to the stroke system serving the Greater Vancouver and Fraser Valley Area, BC, Canada.

In the Greater Vancouver and Fraser Valley Area, there was an annual increase of 36 patients with an excellent outcome, translating to an annual cost savings of CA$2 182 824 to the British Columbia healthcare system. We also studied how these results change depending on our assumptions of treatment times at the regional stroke centers.

Our framework quantifies the impact of optimized emergency stroke transport protocols on hospital volume, outcomes, and cost savings to a single-payer healthcare system. When applied to a specific region of interest, these models can help inform health policies concerning emergency transport of patients with suspected large-vessel occlusion.

Rosuvastatin Slows Progression of Carotid Intima-Media Thickness: The METEOR-China Randomized Controlled Study.

Stroke

URL: https://www.

This randomized, double-blind, placebo-controlled, multicenter, parallel-group study assessed the effects of rosuvastatin 20 mg/d compared with placebo on progression of CIMT over 104 weeks in Chinese people with subclinical atherosclerosis. The primary end point was the annualized rate of change in mean of the maximum CIMT measurements taken 7× over the study period from each of 12 carotid artery sites (near and far walls of the right and left common carotid artery, carotid bulb, and internal carotid artery). Secondary end points included CIMT changes at different artery sites and lipid-parameter changes. Safety was also assessed.

gov; Unique identifier: NCT02546323.

Rosuvastatin 20 mg/d significantly reduced the progression of CIMT over 2 years in Chinese adults with subclinical atherosclerosis and was well tolerated.

Incidence of Stroke in Randomized Trials of COVID-19 Therapeutics: A Systematic Review and Meta-Analysis.

Stroke

COVID-19 has been frequently associated with an increased risk of thrombotic complications. There have also been reports of an increased likelihood of stroke, although its true incidence in patients with COVID-19 is currently unknown.

Electronic databases PubMed and Scopus were searched from inception up to July 30, 2021 to identify randomized controlled studies in patients with confirmed COVID-19 undergoing one or more interventions. Studies were screened for eligibility using a predefined inclusion criterion and selected using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A random-effects model meta-analysis was conducted, and heterogeneity was assessed using I-squared test.

Out of 3960 potentially eligible articles, 77 randomized studies (38 732 patients) were included. Mean age of the study population was 55±9.3 years. Females constituted 38% of the study population and mean duration of follow-up after study enrollment was 23±12.9 days. Cumulative incidence of stroke in the overall study population was 0.001 (95% CI, 0.001-0.002) with a total of 65 events in 38 732 patients, corresponding to an absolute incidence of 0.168%. Incidence of stroke in the inpatient population was 0.001 (95% CI, 0.001-0.002; 65 events in 37 069 patients), corresponding to an absolute incidence of 0.175%. No strokes were observed in the outpatient setting.

The overall incidence of stroke in patients with COVID-19 appears to be lower than that reported in previous observational reports.

Temporal Trends of Functional Outcome in Patients With Acute Ischemic Stroke Treated With Intravenous Thrombolysis.

Stroke

Intravenous thrombolysis improves functional outcome in patients with acute stroke and frequencies of r-tPA (recombinant tissue-type plasminogen activator) treatment have been increasing over time. We aimed to assess whether functional outcome in r-tPA-treated patients improved over time and to investigate the influence of clinical variables on functional outcome.

We analyzed data of r-tPA-treated patients in the Austrian Stroke Unit Registry from 2006 to 2019. Favorable functional outcome was defined as modified Rankin Scale score of 0 to 2. Frequencies of modified Rankin Scale score of 0 to 2 were assessed for the overall population and in prespecified subgroups; multivariable logistic regression analysis was performed to assess associations of baseline characteristics including clinically relevant interactions, and outcome.

Overall, 4865 out of 9409 r-tPA-treated patients (51.7%) achieved favorable functional outcome 3 months post stroke. Between 2006 and 2019, frequencies of favorable functional outcome increased from 45.9% to 56.8%. In multivariable logistic regression analysis, year of treatment (adjusted odds ratio [adjOR], 1.08 [95% CI, 1.01-1.15]) was associated with favorable functional outcome. Stroke severity (National Institutes of Health Stroke Scale, adjOR, 0.86 [95% CI, 0.85-0.87]), age (61-70 years: adjOR, 0.67 [95% CI, 0.55-0.80], 71-80 years: adjOR, 0.42 [95% CI, 0.35-0.50], >80 years: adjOR, 0.16 [95% CI, 0.13-0.20]), female sex (adjOR, 0.89 [95% CI, 0.79-0.99]), and various comorbidities (eg, atrial fibrillation, prior stroke, diabetes) were negatively associated. Inclusion of interaction terms into the multivariable logistic regression model suggests a positive effect of year of treatment and endovascular treatment by increasing stroke severity on functional outcome (interaction between year of treatment and National Institutes of Health Stroke Scale: adjOR, 1.01 [95% CI, 1.00-1.02], interaction between National Institutes of Health Stroke Scale and endovascular treatment: adjOR, 1.02 [95% CI, 1.01-1.03]).

Frequencies of favorable functional outcome in r-tPA-treated patients have been increasing over time, likely driven by improved outcome in patients with more severe strokes receiving endovascular treatment. However, some subgroups are still less likely to achieve functional independency and deserve particular attention.

Alteplase for Stroke With Unknown Onset Time in Chronic Kidney Disease: A Pooled Analysis of Individual Participant Data.

Stroke

Although chronic kidney disease (CKD) is associated with worse stroke outcomes, data regarding the influence of CKD on intravenous thrombolysis outcomes are scarce. We sought to assess the efficacy and safety of intravenous thrombolysis for acute ischemic stroke with unknown onset time in patients with CKD.

Patients with an acute stroke of unknown onset time from the EOS trials (Evaluation of Unknown Onset Stroke Thrombolysis) collaboration were evaluated using an individual patient-level database of randomized controlled trials comparing intravenous thrombolysis with placebo/standard treatment. CKD was defined as baseline estimated glomerular filtration rate of <60 ml/min/1.73m2 Mixed-effect logistic-regression analysis was performed to evaluate treatment effects. A favorable outcome was defined as a modified Rankin Scale score of 0 to 1 at 90 days. Safety outcomes were symptomatic intracranial hemorrhage at 22 to 36 hours and 90-day mortality.

Baseline data on renal function were available for 688 of 843 patients. Of these, CKD was present in 146 (21%), including 69 of 351 patients receiving alteplase and 77 of 337 patients receiving placebo/standard treatment. Overall, treatment with alteplase was associated with higher odds of favorable outcome, and CKD did not modify the treatment effect (Pinteraction=0.834). A favorable outcome was observed in 31 of 69 (46%) patients with CKD in the alteplase group and in 28 of 77 (36%) patients with CKD in the control group (adjusted odds ratio, 1.19 [95% CI, 0.55-2.58]). Among patients with CKD, symptomatic intracranial hemorrhage occurred in 2 patients (3%) in the alteplase group but in none of the controls (P=0.133). At 90 days, death was reported in 3 patients (4%) in the alteplase group compared with 2 patients (3%) in the controls (P=0.539).

The present analysis indicates that the benefit of alteplase does not differ between stroke patients with unknown onset time with and without CKD, although the statistical power was lacking to confirm the efficacy in subgroups. This study only applies to mild-to-moderate or predialysis CKD.

Disparities in Reperfusion Therapy and Time Delays Among Patients With Ischemic Stroke and a History of Mental Illness.

Stroke

Comorbid mental illness may delay recognition of stroke symptoms and reduce the chance of reperfusion therapy. The aim of this study was to compare the use of reperfusion therapy and treatment delays in patients with or without a history of mental illness.

A nationwide registry-based cohort study of patients with ischemic stroke. We combined data from the Danish Stroke Registry and the Danish Quality Database for Prehospital Emergency Medical Services from 2016 to 2017 containing information on reperfusion therapy (thrombolysis or thrombectomy) and relevant time stamps. Patients were categorized according to the severity of their mental health history (how recent and severity, for example, hospital- versus primary-based care).

A total of 19 592 admissions were included (18% had a minor, 3% had a moderate, and 3% had a history of major mental illness). Significant differences were found regarding age, comorbidity, and socioeconomic factors. Reperfusion therapy was used in 17% of patients. Patients with a history of mental illness were less likely to receive reperfusion therapy: risk ratios with 95% CI were 0.79 (0.72-0.86) for minor, 0.85 (0.72-0.99) for moderate, and 0.63 (0.51-0.77) for patients with a history major mental illness, respectively. Total prehospital delay was longer for patients with a history of major mental illness compared to patients with no history of mental illness, especially when no call had been made to the emergency medical service. The median times from symptom onset to hospital arrival was 811 minutes (197-2845) and 115 minutes (41-188), respectively. We found no differences regarding door-to-needle time, response time, on-scene time, transport time, nor in time-to-imaging among patients arriving within 4 hours from symptoms onset between patients with and without a history of mental illness.

Almost one-quarter of patients with ischemic stroke had a history of mental illness. Regardless of severity of mental illness, these patients were less likely to receive reperfusion therapy. Longer delays from symptom onset to hospital arrival contributed to the patients' risk of not being eligible for reperfusion therapy.

Home-Based Transcranial Direct Current Stimulation to Enhance Cognition in Stroke: Randomized Controlled Trial.

Stroke

URL: https://cris.nih.go.kr; Unique identifier: KCT0003427.

Twenty-six patients with chronic stroke and cognitive impairment (Korean version of the Montreal Cognitive Assessment [K-MoCA] score <26) were randomized into real and sham RS-tDCS groups and underwent concurrent computerized cognitive training and RS-tDCS. Patients and caregivers underwent training to ensure correct tDCS self-application, were monitored, and treated 5 d/wk for 4 weeks. We investigated several cognition tests including K-MoCA, Korean version of the Dementia Rating Scale-2, Korean-Boston Naming Test, Trail Making Test, Go/No Go, and Controlled Oral Word Association Test at the end of the training sessions and one month later. Repeated-measures ANOVA was used for comparison between the groups and within each group. The adherence rate of the appropriate RS-tDCS session was also investigated.

In within-group comparison, unlike the sham group, the real group showed significant improvement in K-MoCA (Preal=0.004 versus Psham=0.132), particularly in patients with lower baseline K-MoCA (K-MoCA10-17; Preal=0.001 versus Psham=0.835, K-MoCA18-25; Preal=0.060 versus Psham=0.064) or with left hemispheric lesions (left; Preal=0.010 versus Psham=0.454, right; Preal=0.106 versus Psham=0.128). In between-group comparison, a significant difference was observed in K-MoCA in the lower baseline K-MoCA subgroup (K-MoCA10-17; Ptime×group=0.048), but no significant difference was found in other cognitive tests. The adherence rate of successful application of the RS-tDCS was 98.4%, and no serious adverse effects were detected.

RS-tDCS is a safe and feasible rehabilitation modality for post-stroke cognitive dysfunction. Specifically, RS-tDCS is effective in patients with moderate cognitive decline. Additionally, these data demonstrate the potential to enhance home-based cognitive training, although significant differences were not consistently found in between-group comparisons; therefore, further larger studies are needed.

Distribution-Free Approach to the Design and Analysis of Randomized Stroke Trials With the Modified Rankin Scale.

Stroke

Many methods have been suggested for analyzing the modified Rankin Scale (mRS). However, there lacks a unified approach to analysis and sample size determination that properly uses the ordinal nature of the data. We propose a simple method for CI estimation and corresponding sample size determination.

We quantify treatment effect by the win probability (WinP) that a randomly selected patient in the treatment group has an equal or a better mRS score than a patient in the control group. Thus, a win probability of 0.5 means no effect, likened to a draw in competitive sports. We estimate the win probability and its SE based on the ranks of mRS scores, where tied scores are handled by average ranks. Corresponding methods for hypothesis testing, CI estimation, and sample size determination are derived. The methods are evaluated with a simulation study based on real data from 10 randomized stroke trials that used mRS as the outcome measure.

Simulation results demonstrated that the methods performed very well in terms of CI coverage, tail errors, and assurance to achieving the prespecified precision. Because the methods are very simple, we implemented them in an Excel spreadsheet, requiring only user inputs on frequencies of mRS scores in 2 comparison groups.

Sound statistical methods are important for the success of randomized stroke trials. The proposed methods and associated spreadsheet should prove useful for stroke researchers in the planning and analysis of randomized trials. Meta-analysis has also been made easy for trials with ordinal scores.

Associations of Life's Simple 7 With Cerebral Small Vessel Disease.

Stroke

The purpose of this study is to examine the associations of Life's Simple 7 (LS7) with risks of cerebral small vessel disease (CSVD) and its magnetic resonance imaging markers.

Community-dwelling residents in Lishui city in China from the cross-sectional survey of the PRECISE study (Polyvascular Evaluation for Cognitive Impairment and Vascular Events) were included in this study from 2017 to 2019. LS7 was analyzed as the total score, medical score (derived from the 3 metrics based on medical history and testing), and behavioral score (based on 4 metrics based on behaviors), and categorized as poor, intermediate, or ideal. A CSVD score or a modified CSVD score was derived from 4 magnetic resonance imaging markers (lacunes, microbleeds, perivascular spaces, and white matter hyperintensity) at baseline. Binary logistic regression or ordinal logistic regression model was used to estimate the relationship of LS7 scores with CSVD and magnetic resonance imaging markers.

A total of 3061 participants were included in this study. Compared with poor total LS7 score, ideal LS7 total score was associated with reduced adjusted odds of higher CSVD score (common odds ratio [cOR], 0.73 [95% CI, 0.58-0.90]) and higher modified CSVD score (cOR, 0.78 [95% CI, 0.64-0.95]). Compared with poor LS7 medical score, ideal LS7 medical score was associated with reduced adjusted odds of higher CSVD score (cOR, 0.65 [95% CI, 0.53-0.80]) and higher modified CSVD score (cOR, 0.67 [95% CI, 0.56-0.81]). Higher total LS7 score and LS7 medical score were associated with a lower risk of white matter hyperintensities and lacunes. Higher LS7 behavioral score was associated with lower risk of lacunes.

Ideal LS7 score, indicating excellent cardiovascular health, was associated with lower total CSVD burden. Optimizing the risk factors captured by LS7 may reduce the progression of CSVD.