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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Effects of Semaglutide on Stroke Subtypes in Type 2 Diabetes: Post Hoc Analysis of the Randomized SUSTAIN 6 and PIONEER 6.Stroke
SUSTAIN 6 (Trial to Evaluate Cardiovascular and Other Long-Term Outcomes With Semaglutide in Subjects With Type 2 Diabetes) and PIONEER 6 (Peptide Innovation for Early Diabetes Treatment) were randomized cardiovascular outcome trials of subcutaneous and oral semaglutide in people with type 2 diabetes at high cardiovascular risk, respectively. Time to first stroke and stroke subtypes were analyzed using a Cox proportional hazards model stratified by trial with pooled treatment as a factor. The impact of prior stroke, prior myocardial infarction or stroke, age, sex, systolic blood pressure, estimated glomerular filtration rate, and prior atrial fibrillation on treatment effects was assessed using interaction P values. Risk of major adverse cardiovascular event was analyzed according to prior stroke.
gov; Unique identifier: NCT01720446 and NCT02692716.
Semaglutide reduced incidence of any first stroke during the trials versus placebo in people with type 2 diabetes at high cardiovascular risk, primarily driven by small-vessel occlusion prevention. Semaglutide treatment, versus placebo, lowered the risk of stroke irrespective of prior stroke at baseline.
Transdural Revascularization by Multiple Burrhole After Erythropoietin in Stroke Patients With Cerebral Hypoperfusion: A Randomized Controlled Trial.Stroke
This prospective, randomized, blinded-end point trial recruited patients with acute ischemic stroke with a perfusion impairment of grade ≥2 within 14 days of symptom onset, steno-occlusive mechanisms on imaging examinations, and absence of transdural collaterals on transfemoral cerebral angiography. Patients were randomly assigned to receive MBH + EPO or MBH alone. The primary and secondary outcomes were revascularization success (trans-hemispheric and trans-burr hole) at 6 months and adverse events, respectively.
gov; Unique identifier: NCT02603406.
The combination of MBH and EPO is safe and feasible for reinforcing transdural revascularization in acute steno-occlusive patients with perfusion impairments.
Socioeconomic Inequalities in Reperfusion Therapy for Acute Ischemic Stroke.Stroke
Reperfusion therapies (thrombolysis and thrombectomy) are of paramount importance for the recovery after ischemic stroke. We aimed to investigate if socioeconomic status (SES) was associated with the chance of receiving reperfusion therapy for ischemic stroke in a country with tax-funded health care.
This nationwide register-based cohort study included patients with ischemic stroke registered in the Danish Stroke Registry between 2015 and 2018. SES was determined by prestroke educational attainment, income level, and employment status. Data on SES was obtained from Statistics Denmark and linked on an individual level with data from the Danish Stroke Registry. Risk ratios (RR) for receiving reperfusion therapies were calculated using univariate and multivariable Poisson regression with robust variance.
A total of 37 187 ischemic stroke patients were included. Low SES, as defined by education, income and employment status, was associated with lower treatment rates. The socioeconomic gradient was most pronounced according to employment status, with intravenous thrombolysis rates of 23.7% versus 15.8%, and thrombectomy rates of 5.1% versus 2.8% for employed versus unemployed patients. When the analyses were restricted to patients with timely hospital arrival, and adjusted for age, sex and immigrant status, low SES according to income and employment remained unfavorable for the likelihood of receiving intravenous thrombolysis: adjusted RR, 0.90 (95% CI, 0.86-0.95) for low versus high income, and adjusted RR, 0.77 (95% CI, 0.71-0.84) for unemployed versus employed patients. Similarly, low SES according to income and employment status remained unfavorable for the likelihood of receiving thrombectomy: adjusted RR, 0.83 (95% CI, 0.72-0.95) for low versus high income and adjusted RR, 0.68 (95% CI, 0.53-0.88) for unemployed versus employed patients.
Socioeconomic inequalities in reperfusion treatment rates among ischemic stroke patients prevail, even in a country with tax-funded universal health care.
Automatic Segmentation in Acute Ischemic Stroke: Prognostic Significance of Topological Stroke Volumes on Stroke Outcome.Stroke
Stroke infarct volume predicts patient disability and has utility for clinical trial outcomes. Accurate infarct volume measurement requires manual segmentation of stroke boundaries in diffusion-weighted magnetic resonance imaging scans which is time-consuming and subject to variability. Automatic infarct segmentation should be robust to rotation and reflection; however, prior work has not encoded this property into deep learning architecture. Here, we use rotation-reflection equivariance and train a deep learning model to segment stroke volumes in a large cohort of well-characterized patients with acute ischemic stroke in different vascular territories.
In this retrospective study, patients were selected from a stroke registry at Houston Methodist Hospital. Eight hundred seventy-five patients with acute ischemic stroke in any brain area who had magnetic resonance imaging with diffusion-weighted imaging were included for analysis and split 80/20 for training/testing. Infarct volumes were manually segmented by consensus of 3 independent clinical experts and cross-referenced against radiology reports. A rotation-reflection equivariant model was developed based on U-Net and grouped convolutions. Segmentation performance was evaluated using Dice score, precision, and recall. Ninety-day modified Rankin Scale outcome prediction was also evaluated using clinical variables and segmented stroke volumes in different brain regions.
Segmentation model Dice scores are 0.88 (95% CI, 0.87-0.89; training) and 0.85 (0.82-0.88; testing). The modified Rankin Scale outcome prediction AUC using stroke volume in 30 refined brain regions based upon modified Rankin Scale-relevance areas adjusted for clinical variables was 0.80 (0.76-0.83) with an accuracy of 0.75 (0.72-0.78).
We trained a deep learning model with encoded rotation-reflection equivariance to segment acute ischemic stroke lesions in diffusion- weighted imaging using a large data set from the Houston Methodist stroke center. The model achieved competitive performance in 175 well-balanced hold-out testing cases that include strokes from different vascular territories. Furthermore, the location specific stroke volume segmentations from the deep learning model combined with clinical factors demonstrated high AUC and accuracy for 90-day modified Rankin Scale in an outcome prediction model.
Beyond the Golden Hour: Treating Acute Stroke in the Platinum 30 Minutes.Stroke
To emphasize treatment speed for time-sensitive conditions, emergency medicine has developed not only the concept of the golden hour, but also the platinum half-hour. Patients with acute stroke treated within the first half-hour of onset have not been previously characterized.
In this cohort study, we analyzed patients enrolled in the FAST-MAG (Field Administration of Stroke Therapy-Magnesium) trial, testing paramedic prehospital start of neuroprotective agent ≤2 hours of onset. The features of all acute cerebral ischemia, and intracranial hemorrhage patients with treatment starting at ≤30 m of last known well were compared with later-treated patients.
Among 1680 patients, 203 (12.1%) received study agents within 30 minutes of last known well. Among platinum half-hour patients, median onset-to-treatment time was 28 minutes (interquartile range, 25-30), and final diagnoses were acute cerebral ischemia in 71.8% (ischemic stroke, 61.5%, TIA 10.3%); intracranial hemorrhage in 26.1%; and mimic in 2.5%. Clinical features among platinum half-hour patients were largely similar to later-treated patients and included age 69 (interquartile range, 57-79), 44.8% women, prehospital Los Angeles Motor Scale median 4 (3-5), and early-postarrival National Institutes of Health Stroke Scale deficit 8 (interquartile range, 3-18). Platinum half-hour acute cerebral ischemia patients did have more severe prehospital motor deficits and younger age; platinum half-hour intracranial hemorrhage patients had more severe motor deficits, were more often female, and less often of Hispanic ethnicity. Outcomes at 3 m in platinum half-hour patients were comparable to later-treated patients and included freedom-from-disability (modified Rankin Scale score, 0-1) in 35.5%, functional independence (modified Rankin Scale score, 0-2) in 53.2%, and mortality in 17.7%.
Prehospital initiation permits treatment start within the platinum half-hour after last known well in a substantial proportion of acute ischemic and hemorrhagic stroke patients, accounting for more than 1 in 10 enrolled in a multicenter trial. Hyperacute platinum half-hour patients were largely similar to later-treated patients and are an attainable target for treatment in prehospital stroke trials.
Silent Infarcts, White Matter Integrity, and Oxygen Metabolic Stress in Young Adults With and Without Sickle Cell Trait.Stroke
Individuals with sickle cell anemia have heightened risk of stroke and cognitive dysfunction. Given its high prevalence globally, whether sickle cell trait (SCT) is a risk factor for neurological injury has been of interest; however, data have been limited. We hypothesized that young, healthy adults with SCT would show normal cerebrovascular structure and hemodynamic function.
As a case-control study, young adults with (N=25, cases) and without SCT (N=24, controls) underwent brain magnetic resonance imaging to quantify brain volume, microstructural integrity (fractional anisotropy), silent cerebral infarcts (SCI), intracranial stenosis, and aneurysms. Pseudocontinuous arterial spin labeling and asymmetric spin echo sequences measured cerebral blood flow and oxygen extraction fraction, respectively, from which cerebral metabolic oxygen demand was calculated. Imaging metrics were compared between SCT cases and controls. SCI volume was correlated with baseline characteristics.
Compared with controls, adults with SCT demonstrated similar normalized brain volumes (SCT 0.80 versus control 0.81, P=0.41), white matter fractional anisotropy (SCT 0.41 versus control 0.43, P=0.37), cerebral blood flow (SCT 62.04 versus control, 61.16 mL/min/100 g, P=0.67), oxygen extraction fraction (SCT 0.27 versus control 0.27, P=0.31), and cerebral metabolic oxygen demand (SCT 2.71 versus control 2.70 mL/min/100 g, P=0.96). One per cohort had an intracranial aneurysm. None had intracranial stenosis. The SCT cases and controls showed similar prevalence and volume of SCIs; however, in the subset of participants with SCIs, the SCT cases had greater SCI volume versus controls (0.29 versus 0.07 mL, P=0.008). Of baseline characteristics, creatinine was mildly elevated in the SCT cohort (0.9 versus 0.8 mg/dL, P=0.053) and correlated with SCI volume (ρ=0.49, P=0.032). In the SCT cohort, SCI distribution was similar to that of young adults with sickle cell anemia.
Adults with SCT showed normal cerebrovascular structure and hemodynamic function. These findings suggest that healthy individuals with SCT are unlikely to be at increased risk for early or accelerated ischemic brain injury.
How Much of the Thrombectomy Related Improvement in Functional Outcome Is Already Apparent at 24 Hours and at Hospital Discharge?Stroke
All patients enrolled in the German Stroke Registry (June 2015-December 2019) with anterior circulation stroke and availability of baseline data and neurological status were included. A mediation analysis was conducted to investigate the effect of successful recanalization (Thrombolysis in Cerebral Infarction scale score ≥2b) on good functional outcome (modified Rankin Scale score ≤2 at day 90) with mediation through neurological status (National Institutes of Health Stroke Scale [NIHSS] at 24 hours and at hospital discharge).
gov; Unique identifier: NCT03356392.
Fifty-four percent of the improvement in functional outcome after successful recanalization is apparent in NIHSS at 24 hours, 75% in NIHSS at hospital discharge. Other unknown factors not apparent in NIHSS at the 2 time points investigated account for the remaining effect on long term outcome, suggesting, among others, clinical relevance of delayed neurological improvement and deterioration.
Association of RNF213 Variants With Periventricular Anastomosis in Moyamoya Disease.Stroke
The pathogenic mechanisms of periventricular anastomosis (PA) in moyamoya disease remain unknown. Here, we aimed to describe the angiographic profiles of PA and their relationships with really interesting new gene (RING) finger protein 213 (RNF213) genotypes.
We conducted a retrospective cohort study of moyamoya disease patients consecutively recruited between June 2019 and January 2021 in Beijing Tiantan Hospital, Capital Medical University, China. C-terminal region of RNF213 was sequenced. Angiographic characteristics of PA vessels (lenticulostriate artery, thalamotuberal artery, thalamoperforating artery, anterior choroidal artery, and posterior choroidal artery) were compared between different groups of RNF213 genotypes. The dilatation and extension of PA vessels were measured by using PA score (positive, score 1-5; negative, score 0). Multivariate regression analysis was conducted to assess variables associated with PA score. In addition, gene expression of RNF213 in human brain regions was evaluated from the Allen Human Brain Atlas.
Among 260 patients (484 hemispheres), 71.2% carried no RNF213 rare and novel variants, 20.0% carried p.R4810K heterozygotes, and 8.8% carried other rare and novel variants. PA scores in patients with p.R4810K and other rare and novel variants were significantly higher than in wild-type patients (P<0.001). Age (odds ratio [OR], 0.958 [95% CI, 0.942-0.974]; P<0.001), platelet count (OR, 0.996 [95% CI, 0.992-0.999]; P=0.027), p.R4810K variant (OR, 2.653 [95% CI, 1.514-4.649]; P=0.001), other rare and novel variants (OR, 3.197 [95% CI, 1.012-10.094]; P=0.048), Suzuki stage ≥4 (OR, 1.941 [95% CI, 1.138-3.309]; P=0.015), and posterior cerebral artery involvement (OR, 1.827 [95% CI, 1.020-3.271]; P=0.043) were significantly correlated with PA score. High expression of RNF213 was detected in the periventricular area.
RNF213 variants were confirmed to be associated with PA in moyamoya disease. Individuals with RNF213 p.R4810K heterozygotes and other C-terminal region rare variants exhibited different angiographic phenotypes, compared with wild-type patients.
Fragility Index Meta-Analysis of Randomized Controlled Trials Shows Highly Robust Evidential Strength for Benefit of <3 Hour Intravenous Alteplase.Stroke
Cumulative fragility index (FI) analysis enables quantification of the evidential strength of intravenous alteplase's core indication-treatment of disabling acute ischemic stroke within 3 hours of onset.
Meta-analyses were performed (study level) or identified (individual participant level) for freedom-from-disability (modified Rankin Scale [mRS] score 0-1, primary efficacy), functional independence (mRS score 0-2, secondary efficacy), and mortality outcomes. Individual trial and cumulative FI analyses were serially conducted after each successive randomized controlled trial (RCT). FI scores were classified as follows: not robust (FI 0-4), somewhat robust (FI 5-12), robust (FI 13-33), and highly robust (FI >33).
Nine randomized controlled trials were identified from 1995 to 2021 of within-3-hour intravenous alteplase for acute ischemic stroke. In study-level meta-analyses, alteplase increased freedom-from-disability outcome (mRS score 0-1), 31.0% versus 22.3%, relative risk, 1.39 (95% CI, 1.20-1.61); P<0.00001; increased functional independence (mRS score 0-2), 39.7% versus 31.2%, relative risk, 1.29 (95% CI, 1.14-1.45), P<0.000; and did not alter mortality, 24.1% versus 26.1%; P=0.23. Overall FIs for study-level meta-analyses were both highly robust at 42 and 40 for mRS score 0-1 and mRS score 0-2, respectively. Serial FI analyses showed robust evidential strength for intravenous alteplase superiority with publication of the 2 NINDS-tPA trials (National Institute of Neurological Disorders and Stroke-tissue-type plasminogen activator) in 1995, increased to highly robust in 2012, and remains highly robust in 2021.
Within-3-hour intravenous alteplase for acute ischemic stroke is one of the most robustly proven therapies in medicine. The initial concurrent trials 25 years ago showed robust evidence for benefit and, after additional studies, advanced to highly robust.
Etiology of Large Vessel Occlusion Posterior Circulation Stroke: Results of the MR CLEAN Registry.Stroke
In patients with large vessel occlusion stroke of the anterior circulation, underlying cause is a determinant of outcome. Whether this is the case for posterior circulation large vessel occlusion stroke has yet to be determined. We aimed to report on cause in patients with posterior circulation stroke treated with endovascular thrombectomy and to analyze the association with functional outcome.
We used data of patients with posterior circulation stroke included in the MR CLEAN (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) registry, a prospective multicenter observational study, between 2014 and 2018. Stroke cause was categorized into large artery atherosclerosis (LAA), cardioembolism, arterial dissection, embolic stroke of undetermined source (ESUS), other determined cause, or undetermined cause. For primary analysis on the association between cause and outcome, we used multivariable ordinal logistic regression analysis to estimate the adjusted common odds ratio for a shift towards a better functional outcome on the modified Rankin Scale at 90 days with LAA as a reference group. Secondary outcomes included favorable functional outcome (modified Rankin Scale score 0-3), National Institutes of Health Stroke Scale score at 24 to 48 hours, reperfusion on digital subtraction angiography, and stroke progression.
Of 264 patients with posterior circulation stroke, 84 (32%) had LAA, 48 (18%) cardioembolism, 31 (12%) dissection, and 14 (5%) ESUS. Patients with a dissection were younger (48 [interquartile range, 43-60] years) and had a lower National Institutes of Health Stroke Scale at baseline (12 [interquartile range, 6-31]) than patients with other cause. Functional outcome was better for patients with cardioembolism and ESUS compared to LAA (modified Rankin Scale adjusted common odds ratio, 2.4 [95% CI, 1.1-5.2], respectively adjusted common odds ratio, 3.1 [95% CI, 1.0-9.3]). Patients with a dissection had a lower chance of successful reperfusion compared with LAA (adjusted odds ratio, 0.20 [95% CI, 0.06-0.70]).
Unlike the anterior circulation, most frequent cause in our posterior large vessel occlusion stroke cohort is LAA followed by cardioembolism, dissection, and ESUS. Patients with cardioembolism and ESUS have a better prognosis for functional outcome after endovascular thrombectomy than patients with LAA.
Remnant Cholesterol Variability and Incident Ischemic Stroke in the General Population.Stroke
Studies have demonstrated that remnant cholesterol is correlated with the risk of ischemic stroke. However, it is unknown whether visit-to-visit variability in remnant cholesterol concentration affects ischemic stroke. We sought to examine the role of remnant cholesterol variability in the subsequent development of ischemic stroke in the general population.
We performed a post hoc analysis including eligible participants from the Kailuan Study cohort who underwent 3 health examinations and were free of atrial fibrillation, myocardial infarction, stroke, cancer, or known lipid-medication use from 2006 to 2010. Participants were followed up until the end of 2017. Variability was quantified as variability independent of the mean, average real variability, and SD. Multivariate analysis was performed using the Fine and Gray competing risk model to estimate subhazard ratios assuming death as a competing risk.
The final study cohort comprised 38 556 participants. After a median follow-up of 7.0 years, 1058 individuals were newly diagnosed with ischemic stroke. After adjusting for age (time scale), sex, smoking status, alcohol consumption, physical activity, hypertension, diabetes, family history of cardiovascular disease, body mass index, estimated glomerular filtration rate, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and mean remnant cholesterol, the highest quartile (quartile 4) of variability independent of the mean of remnant cholesterol was associated with an increased ischemic stroke risk compared with the lowest quartile (quartile 1), (subhazard ratio, 1.27 [95% CI, 1.06-1.53]). For each 1-SD increase in variability independent of the mean of remnant cholesterol, the risk increased by 9% (subhazard ratio, 1.09 [95% CI, 1.03-1.16]). The association was also significant using average real variability and SD as indices of variability.
Greater remnant cholesterol variability was associated with a higher risk of ischemic stroke in the general population.
Recurrent Ischemic Stroke and Bleeding in Patients With Atrial Fibrillation Who Suffered an Acute Stroke While on Treatment With Nonvitamin K Antagonist Oral Anticoagulants: The RENO-EXTEND Study.Stroke
In patients with atrial fibrillation who suffered an ischemic stroke while on treatment with nonvitamin K antagonist oral anticoagulants, rates and determinants of recurrent ischemic events and major bleedings remain uncertain.
This prospective multicenter observational study aimed to estimate the rates of ischemic and bleeding events and their determinants in the follow-up of consecutive patients with atrial fibrillation who suffered an acute cerebrovascular ischemic event while on nonvitamin K antagonist oral anticoagulant treatment. Afterwards, we compared the estimated risks of ischemic and bleeding events between the patients in whom anticoagulant therapy was changed to those who continued the original treatment.
After a mean follow-up time of 15.0±10.9 months, 192 out of 1240 patients (15.5%) had 207 ischemic or bleeding events corresponding to an annual rate of 13.4%. Among the events, 111 were ischemic strokes, 15 systemic embolisms, 24 intracranial bleedings, and 57 major extracranial bleedings. Predictive factors of recurrent ischemic events (strokes and systemic embolisms) included CHA2DS2-VASc score after the index event (odds ratio [OR], 1.2 [95% CI, 1.0-1.3] for each point increase; P=0.05) and hypertension (OR, 2.3 [95% CI, 1.0-5.1]; P=0.04). Predictive factors of bleeding events (intracranial and major extracranial bleedings) included age (OR, 1.1 [95% CI, 1.0-1.2] for each year increase; P=0.002), history of major bleeding (OR, 6.9 [95% CI, 3.4-14.2]; P=0.0001) and the concomitant administration of an antiplatelet agent (OR, 2.8 [95% CI, 1.4-5.5]; P=0.003). Rates of ischemic and bleeding events were no different in patients who changed or not changed the original nonvitamin K antagonist oral anticoagulants treatment (OR, 1.2 [95% CI, 0.8-1.7]).
Patients suffering a stroke despite being on nonvitamin K antagonist oral anticoagulant therapy are at high risk of recurrent ischemic stroke and bleeding. In these patients, further research is needed to improve secondary prevention by investigating the mechanisms of recurrent ischemic stroke and bleeding.