The latest medical research on Stroke

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 stroke gathered by our medical AI research bot.

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Stroke Recovery-Related Changes in Cortical Reactivity Based on Modulation of Intracortical Inhibition.

Stroke

Cortical excitation/inhibition dynamics have been suggested as a key mechanism occurring after stroke. Their supportive or maladaptive role in the course of recovery is still not completely understood. Here, we used transcranial magnetic stimulation (TMS)-electroencephalography coupling to study cortical reactivity and intracortical GABAergic inhibition, as well as their relationship to residual motor function and recovery longitudinally in patients with stroke.

Electroencephalography responses evoked by TMS applied to the ipsilesional motor cortex were acquired in patients with stroke with upper limb motor deficit in the acute (1 week), early (3 weeks), and late subacute (3 months) stages. Readouts of cortical reactivity, intracortical inhibition, and complexity of the evoked dynamics were drawn from TMS-evoked potentials induced by single-pulse and paired-pulse TMS (short-interval intracortical inhibition). Residual motor function was quantified through a detailed motor evaluation.

From 76 patients enrolled, 66 were included (68.2±13.2 years old, 18 females), with a Fugl-Meyer score of the upper extremity of 46.8±19. The comparison with TMS-evoked potentials of healthy older revealed that most affected patients exhibited larger and simpler brain reactivity patterns (Pcluster<0.05). Bayesian ANCOVA statistical evidence for a link between abnormally high motor cortical excitability and impairment level. A decrease in excitability in the following months was significantly correlated with better motor recovery in the whole cohort and the subgroup of recovering patients. Investigation of the intracortical GABAergic inhibitory system revealed the presence of beneficial disinhibition in the acute stage, followed by a normalization of inhibitory activity. This was supported by significant correlations between motor scores and the contrast of local mean field power and readouts of signal dynamics.

The present results revealed an abnormal motor cortical reactivity in patients with stroke, which was driven by perturbations and longitudinal changes within the intracortical inhibition system. They support the view that disinhibition in the ipsilesional motor cortex during the first-week poststroke is beneficial and promotes neuronal plasticity and recovery.

Implementing Telestroke in the Inpatient Setting: Identifying Factors for Success.

Stroke

Inpatient telestroke programs have emerged as a solution to provide timely stroke care in underserved areas, but their successful implementation and factors influencing their effectiveness remain underexplored. This study aimed to qualitatively evaluate the perspectives of inpatient clinicians located at spoke hospitals participating in a newly established inpatient telestroke program to identify implementation barriers and facilitators.

This was a formative evaluation relying on semistructured qualitative interviews with 16 inpatient providers (physicians and nurse practitioners) at 5 spoke sites of a hub-and-spoke inpatient telestroke program. The Integrated-Promoting Action on Research Implementation in Health Services framework guided data analysis, focusing on the innovation, recipients, context, and facilitation aspects of implementation. Interviews were transcribed and coded using thematic analysis.

Fifteen themes were identified in the data and mapped to the Integrated-Promoting Action on Research Implementation in Health Services framework. Themes related to the innovation (the telestroke program) included easy access to stroke specialists, the benefits of limiting patient transfers, concerns about duplicating tests, and challenges of timing inpatient telestroke visits and notes to align with discharge workflow. Themes pertaining to recipients (care team members and patients) were communication gaps between teams, concern about the supervision of inpatient telestroke advanced practice providers and challenges with nurse empowerment. With regard to the context (hospital and system factors), providers highlighted familiarity with telehealth technologies as a facilitator to implementing inpatient telestroke, yet highlighted resource limitations in smaller facilities. Facilitation (program implementation) was recognized as crucial for education, standardization, and buy-in.

Understanding barriers and facilitators to implementation is crucial to determining where programmatic changes may need to be made to ensure the success and sustainment of inpatient telestroke services.

Exploring Genetic Associations of 3 Types of Risk Factors With Ischemic Stroke: An Integrated Bioinformatics Study.

Stroke

Ischemic stroke (IS) is a major cause of disability and mortality worldwide. Increasing evidence suggests a strong association between blood pressure, blood glucose, circulating lipids, and IS. Nonetheless, the genetic association of these 3 risk factors with IS remains elusive.

We screened genetic instruments related to blood pressure, blood glucose, and circulating lipids and paired them with IS genome-wide association study data to conduct Mendelian randomization analysis. Positive Mendelian randomization findings were then subjected to colocalization analysis. Subsequently, we utilized the Gene Expression Omnibus data set to perform differential expression analysis, aiming to identify differentially expressed associated genes. We determined the importance scores of these differentially expressed associated genes through 4 machine learning models and constructed a nomogram based on these findings.

The combined results of the Mendelian randomization analysis indicate that blood pressure (systolic blood pressure: odds ratio [OR], 1.02 [95% CI, 1.01-1.02]; diastolic blood pressure: OR, 1.03 [95% CI, 1.03-1.04]) and some circulating lipids (low-density lipoprotein cholesterol: OR, 1.06 [95% CI, 1.01-1.12]; apoA1: OR, 0.95 [95% CI, 0.92-0.98]; apoB: OR, 1.05 [95% CI, 1.01-1.09]; eicosapentaenoic acid: OR, 2.36 [95% CI, 1.41-3.96]) have causal relationships with the risk of IS onset. We identified 73 genes that are linked to blood pressure and circulating lipids in the context of IS, and 16 are differentially expressed associated genes. FURIN, MAN2A2, HDDC3, ALDH2, and TOMM40 were identified as feature genes for constructing the nomogram that provides a quantitative prediction of the risk of IS onset.

This study indicates that there are causal links between blood pressure, certain circulating lipids, and the development of IS. The potential mechanisms underlying these causal relationships involve the regulation of lipid metabolism, blood pressure, DNA repair and methylation, cell apoptosis and autophagy, immune inflammation, and neuronal protection, among others.

Global, Regional, and National Burdens of Stroke in Children and Adolescents From 1990 to 2019: A Population-Based Study.

Stroke

Stroke is one of the leading causes of death among children, yet evidence on stroke incidence and prognosis in this population is largely neglected worldwide. The aim of this study was to estimate the latest burden of childhood stroke, as well as trends, risk factors, and inequalities from 1990 to 2019, at the global, regional, and national levels.

The Global Burden of Disease 2019 study was utilized to evaluate the prevalence, incidence, years lived with disability, years of life lost (YLLs), and average annual percentage changes in stroke among populations aged 0 to 19 years from 1990 to 2019.

The global age-standardized incidence of stroke increased (average annual percentage change, 0.15% [95% uncertainty interval, 0.09%-0.21%]), while YLLs decreased substantially (average annual percentage change, -3.33% [95% uncertainty interval, -3.38% to -3.28%]) among children and adolescents between 1990 and 2019. Ischemic stroke accounted for 70% of incident cases, and intracerebral hemorrhage accounted for 63% of YLLs. Children under 5 years of age had the highest incidence of ischemic stroke, while adolescents aged 15 to 19 years had the highest incidence of hemorrhagic stroke. In 2019, low-income and middle-income countries were responsible for 84% of incident cases and 93% of YLLs due to childhood stroke. High-sociodemographic index countries had a reduction in YLLs due to stroke that was more than twice as fast as that of low-income and middle-income.

Globally, the burden of childhood stroke continues to increase, especially among females, children aged <5 years, and low-sociodemographic index countries, such as sub-Saharan Africa. The burden of childhood stroke is likely undergoing a significant transition from being fatal to causing disability. Global public health policies and the deployment of health resources need to respond rapidly and actively to this shift.

LDL-c Lowering, Ischemic Stroke, and Small Vessel Disease Brain Imaging Biomarkers: A Mendelian Randomization Study.

Stroke

The effects of lipid-lowering drug targets on different ischemic stroke subtypes are not fully understood. We aimed to explore the mechanisms by which lipid-lowering drug targets differentially affect the risk of ischemic stroke subtypes and their underlying pathophysiology.

Using a 2-sample Mendelian randomization approach, we assessed the effects of genetically proxied low-density lipoprotein cholesterol (LDL-c) and 3 clinically approved LDL-lowering drugs (HMGCR [3-hydroxy-3-methylglutaryl-CoA reductase], PCSK9 [proprotein convertase subtilisin/kexin type 9], and NPC1L1 [Niemann-Pick C1-Like 1]) on stroke subtypes and brain imaging biomarkers associated with small vessel stroke (SVS), including white matter hyperintensity volume and perivascular spaces.

In genome-wide Mendelian randomization analyses, lower genetically predicted LDL-c was significantly associated with a reduced risk of any stroke, ischemic stroke, and large artery stroke, supporting previous findings. Significant associations between genetically predicted LDL-c and cardioembolic stroke, SVS, and biomarkers, perivascular space and white matter hyperintensity volume, were not identified in this study. In drug-target Mendelian randomization analysis, genetically proxied reduced LDL-c through NPC1L1 inhibition was associated with lower odds of perivascular space (odds ratio per 1-mg/dL decrease, 0.79 [95% CI, 0.67-0.93]) and with lower odds of SVS (odds ratio, 0.29 [95% CI, 0.10-0.85]).

This study provides supporting evidence of a potentially protective effect of LDL-c lowering through NPC1L1 inhibition on perivascular space and SVS risk, highlighting novel therapeutic targets for SVS.

Thrombectomy in Patients With Ischemic Stroke Without Salvageable Tissue on CT Perfusion.

Stroke

Computed tomography perfusion (CTP) imaging is regularly used to guide patient selection for mechanical thrombectomy (MT). However, the effect of MT in patients without salvageable tissue on CTP has not been investigated. The purpose of this study was to assess the effect of MT in patients with stroke without perfusion mismatch profiles.

This observational study analyzed patients with ischemic stroke consecutively treated between March 1, 2015, and January 31, 2022, triaged by multimodal-computed tomography undergoing MT. CTP lesion-core mismatch profiles were defined using a mismatch volume/ratio of ≥10 mL/1.2, respectively. The primary end point was the rate of functional independence at 90 days, defined as the modified Rankin Scale score of 0 to 2. Recanalization was evaluated with the modified Thrombolysis in Cerebral Infarction scale. The effect of baseline variables on functional outcome was assessed using multivariable logistic regression analysis. Outcomes of patients with and without CTP-mismatch profiles were compared using 1:1 propensity score matching.

Of 724 patients who met the inclusion criteria of this retrospective observational study, 110 (15%) patients had no CTP mismatch and were analyzed. The median age was 74 (interquartile range, 62-80) years and 53% were women. Successful recanalization (modified Thrombolysis in Cerebral Infarction score, ≥2b) was achieved in 66% (73) and associated with functional independence at 90 days (adjusted odds ratio, 7.33 [95% CI, 1.22-43.70]; P=0.03). A significant interaction was observed between recanalization and age, as well as the extent of infarction, indicating MT to be most effective in patients <70 years and with a baseline Alberta Stroke Program Early Computed Tomography Score range between 3 and 7. These findings remained stable after propensity score matching, analyzing 152 matched pairs with similar rates of functional independence between patients with and without CTP-mismatch profiles (17% versus 23%; P=0.42).

In patients without CTP-mismatch profiles defined according to the EXTEND (Extending the Time for Thrombolysis in Emergency Neurological Deficits) criteria, recanalization was associated with improved functional outcomes. This effect was associated with baseline Alberta Stroke Program Early Computed Tomography Score and age, but not with the time from onset to imaging.

Outcomes of Decompressive Surgery for Patients With Severe Cerebral Venous Thrombosis: DECOMPRESS2 Observational Study.

Stroke

Decompressive neurosurgery is recommended for patients with cerebral venous thrombosis (CVT) who have large parenchymal lesions and impending brain herniation. This recommendation is based on limited evidence. We report long-term outcomes of patients with CVT treated by decompressive neurosurgery in an international cohort.

DECOMPRESS2 (Decompressive Surgery for Patients With Cerebral Venous Thrombosis, Part 2) was a prospective, international cohort study. Consecutive patients with CVT treated by decompressive neurosurgery were evaluated at admission, discharge, 6 months, and 12 months. The primary outcome was death or severe disability (modified Rankin Scale scores, 5-6) at 12 months. The secondary outcomes included patient and caregiver opinions on the benefits of surgery. The association between baseline variables before surgery and the primary outcome was assessed by multivariable logistic regression.

A total of 118 patients (80 women; median age, 38 years) were included from 15 centers in 10 countries from December 2011 to December 2019. Surgery (115 craniectomies and 37 hematoma evacuations) was performed within a median of 1 day after diagnosis. At last assessment before surgery, 68 (57.6%) patients were comatose, fixed dilated pupils were found unilaterally in 27 (22.9%) and bilaterally in 9 (7.6%). Twelve-month follow-up data were available for 113 (95.8%) patients. Forty-six (39%) patients were dead or severely disabled (modified Rankin Scale scores, 5-6), of whom 40 (33.9%) patients had died. Forty-two (35.6%) patients were independent (modified Rankin Scale scores, 0-2). Coma (odds ratio, 2.39 [95% CI, 1.03-5.56]) and fixed dilated pupil (odds ratio, 2.22 [95% CI, 0.90-4.92]) were predictors of death or severe disability. Of the survivors, 56 (78.9%) patients and 61 (87.1%) caregivers expressed a positive opinion on surgery.

Two-thirds of patients with severe CVT were alive and more than one-third were independent 1 year after decompressive surgery. Among survivors, surgery was judged as worthwhile by 4 out of 5 patients and caregivers. These results support the recommendation to perform decompressive neurosurgery in patients with CVT with impending brain herniation.

Uncommon Causes of Nontraumatic Intracerebral Hemorrhage.

Stroke

Nontraumatic intracerebral hemorrhage is an important health issue. Although common causes such as hypertension and cerebral amyloid angiopathy pre...

Mechanism of Action and Translational Potential of (S)-Meclizine in Preemptive Prophylaxis Against Stroke.

Stroke

Mild chemical inhibition of mitochondrial respiration can confer resilience against a subsequent stroke or myocardial infarction, also known as preconditioning. However, the lack of chemicals that can safely inhibit mitochondrial respiration has impeded the clinical translation of the preconditioning concept. We previously showed that meclizine, an over-the-counter antivertigo drug, can toggle metabolism from mitochondrial respiration toward glycolysis and protect against ischemia-reperfusion injury in the brain, heart, and kidney. Here, we examine the mechanism of action of meclizine and report the efficacy and improved safety of the (S) enantiomer.

We determined the anoxic depolarization latency, tissue and neurological outcomes, and glucose uptake using micro-positron emission tomography after transient middle cerebral artery occlusion in mice pretreated (-17 and -3 hours) with either vehicle or meclizine. To exclude a direct effect on tissue excitability, we also examined spreading depression susceptibility. Furthermore, we accomplished the chiral synthesis of (R)- and (S)-meclizine and compared their effects on oxygen consumption and histamine H1 receptor binding along with their brain concentrations.

Micro-positron emission tomography showed meclizine increases glucose uptake in the ischemic penumbra, providing the first in vivo evidence that the neuroprotective effect of meclizine indeed stems from its ability to toggle metabolism toward glycolysis. Consistent with reduced reliance on oxidative phosphorylation to sustain the metabolism, meclizine delayed anoxic depolarization onset after middle cerebral artery occlusion. Moreover, the (S) enantiomer showed reduced H1 receptor binding, a dose-limiting side effect for the racemate, but retained its effect on mitochondrial respiration. (S)-meclizine was at least as efficacious as the racemate in delaying anoxic depolarization onset and decreasing infarct volumes after middle cerebral artery occlusion.

Our data identify (S)-meclizine as a promising new drug candidate with high translational potential as a chemical preconditioning agent for preemptive prophylaxis in patients with high imminent stroke or myocardial infarction risk.

Near-Infrared II Photobiomodulation Preconditioning Ameliorates Stroke Injury via Phosphorylation of eNOS.

Stroke

The current management of patients with stroke with intravenous thrombolysis and endovascular thrombectomy is effective only when it is timely performed on an appropriately selected but minor fraction of patients. The development of novel adjunctive therapy is highly desired to reduce morbidity and mortality with stroke. Since endothelial dysfunction is implicated in the pathogenesis of stroke and is featured with suppressed endothelial nitric oxide synthase (eNOS) with concomitant nitric oxide deficiency, restoring endothelial nitric oxide represents a promising approach to treating stroke injury.

This is a preclinical proof-of-concept study to determine the therapeutic effect of transcranial treatment with a low-power near-infrared laser in a mouse model of ischemic stroke. The laser treatment was performed before the middle cerebral artery occlusion with a filament. To determine the involvement of eNOS phosphorylation, unphosphorylatable eNOS S1176A knock-in mice were used. Each measurement was analyzed by a 2-way ANOVA to assess the effect of the treatment on cerebral blood flow with laser Doppler flowmetry, eNOS phosphorylation by immunoblot analysis, and stroke outcomes by infarct volumes and neurological deficits.

Pretreatment with a 1064-nm laser at an irradiance of 50 mW/cm2 improved cerebral blood flow, eNOS phosphorylation, and stroke outcomes.

Near-infrared II photobiomodulation could offer a noninvasive and low-risk adjunctive therapy for stroke injury. This new modality using a physical parameter merits further consideration to develop innovative therapies to prevent and treat a wide array of cardiovascular diseases.

Genetically Determined Plasma Hepatocyte Growth Factor Levels Are Associated With the Risk and Prognosis of Ischemic Stroke.

Stroke

Observational studies suggest that hepatocyte growth factor (HGF) is associated with the risk and prognosis of ischemic stroke, but the causality of these associations remains unclear. Therefore, we conducted Mendelian randomization (MR) analyses to explore the associations of genetically determined plasma HGF levels with the risk and prognosis of ischemic stroke.

A total of 13 single-nucleotide polymorphisms associated with plasma HGF were selected as genetic instruments based on the data from a genome-wide association study with 21 758 European participants. Summary data about the risk of ischemic stroke were obtained from the MEGASTROKE (Multiancestry Genome-Wide Association Study of Stroke) Consortium with 34 217 ischemic stroke cases and 406 111 controls of European ancestry, and summary data about the prognosis of ischemic stroke were obtained from the GISCOME study (Genetics of Ischaemic Stroke Functional Outcome) with 6165 European patients with ischemic stroke. We conducted an inverse-variance weighted Mendelian randomization analysis followed by a series of sensitivity analyses to evaluate the associations of genetically determined plasma HGF with the risk and prognosis of ischemic stroke.

The primary analyses showed that genetically determined high HGF was associated with an increased risk of ischemic stroke (odds ratio per SD increase, 1.11 [95% CI, 1.04-1.19]; P=1.10×10-3) and poor prognosis of ischemic stroke (odds ratio per SD increase, 2.43 [95% CI, 1.76-3.52]; P=6.35×10-8). In the secondary analysis, genetically determined plasma HGF was associated with a high risk of large atherosclerotic stroke (odds ratio per SD increase, 1.39 [95% CI, 1.18-1.63]; P=5.08×10-5) but not small vessel stroke and cardioembolic stroke. Mendelian randomization-Egger regression showed no directional pleiotropy for all associations, and the sensitivity analyses with different Mendelian randomization methods further confirmed these findings.

We found positive associations of genetically determined plasma HGF with the risk and prognosis of ischemic stroke, suggesting that HGF might be implicated in the occurrence and development of ischemic stroke.

Caring for Stroke Survivors: Ethnic Differences in Informal Caregiver Needs Among Mexican American and Non-Hispanic White Communities.

Stroke

After stroke, Mexican American (MA) individuals have worse 90-day neurological, functional, cognitive, and quality of life outcomes and a higher prevalence of poststroke depression compared with non-Hispanic White (NHW) individuals. MA individuals receive more help through informal, unpaid caregiving than NHW individuals. We examined ethnic differences in needs identified by MA and NHW stroke caregivers.

Caregivers were identified from the population-based BASIC study (Brain Attack Surveillance in Corpus Christi) in Nueces County, Texas from October 2019 to November 2021. Responses to the Caregiver Needs and Concerns Checklist were collected at 90-day poststroke to assess caregiver needs. Using the cross-sectional sample, prevalence scores and bivariate analyses were used to examine ethnic differences between Caregiver Needs and Concerns Checklist items. Linear regression was used to examine adjusted associations of ethnicity with the total average needs for each domain. Models were adjusted for patient and caregiver age and sex, caregiver education level, and employment status, patient insurance status, prestroke function, cognitive status, language, and functional outcome at 90 days, intensity and duration of caregiving, presence of other caregivers (paid/unpaid), and cohabitation of patient and caregiver.

A total of 287 were approached, and 186 stroke caregivers were included with a median age of 54.2 years and 80.1% being women caregivers: 74.3% MA and 25.7% NHW individuals. MA caregivers had significantly lower education (<high school degree: 33.8% versus 6.4%; P=0.0011) and income (<$30 000 income: 54.0% versus 28.9%; P=0.0049), and more likely used while providing care (56.8% versus 38.3%; P=0.0423). MA caregivers reported greater need than NHW caregivers on over two-thirds of the items and reported significantly greater need for the information domain (B, 0.17 [99.17% CI, 0.02-0.32]).

MA stroke caregivers have greater information needs compared with NHW caregivers and a greater number of needs overall. This information can help improve resources to help with poststroke recovery, improve caregiver well-being, and strengthen health equity.