A population-based study of the incidence and prognosis of lacunar stroke

The effect of hypertension, obesity, and type 2 diabetes on lacunar stroke: A network Mendelian randomization study

BACKGROUND AND AIMS

Previous studies have reported an association of lacunar stroke with hypertension, obesity, and type 2 diabetes (T2D). The aim of this study was to investigate whether the association was causal and whether body mass index mediated the effect of hypertension on lacunar stroke.

METHODS AND RESULTS

The independence and causal association of hypertension, obesity, and T2D with lacunar stroke were assessed by multivariate Mendelian randomization (MVMR) and network Mendelian randomization (NMR) with inverse variance weighting (IVW). The reliability of the results was increased by sensitivity analyses including MR-Egger, Cochrane's Q test, Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and leave-one-out. MVMR analysis found that genetically predicted hypertension had a 42 % higher lacunar stroke risk (OR: 1.42, 95 % CI: 1.29-1.56, P < 0.001) when adjusted for obesity and T2D, genetically predicted T2D had a 9 % higher lacunar stroke risk (OR: 1.09, 95 % CI: 1.03-1.16, P < 0.004) when adjusted for hypertension and obesity, and genetically predicted obesity had a 15 % lower lacunar stroke risk (OR: 0.85, 95 % CI: 0.77-0.93, P < 0.001) when adjusted for hypertension and T2D. NMR found that 44 % of the association between hypertension and lacunar stroke risk was mediated by obesity.

CONCLUSION

This genetic association study found novel independent genetic associations between hypertension and T2D with high risk of lacunar stroke, whereas obesity attenuated the risk of lacunar stroke. The findings emphasize the importance of individualized lacunar stroke prevention strategies rather than uniform weight management optimize medical care in high-risk populations.

Thrombolysis in lacunar stroke: Comparison of early neurological improvement and 90-day functional outcome with cardioembolic stroke without large-vessel occlusion

INTRODUCTION

Thrombolysis (IVT) is effective in the treatment of lacunar stroke (LAC). However, most studies compared the outcome of LAC to a heterogenous control group. We aimed to compare early neurological improvement (ENI) and late functional outcomes following thrombolysis for LAC with a homogenous control group of cardioembolic stroke (CE) without large-vessel occlusion (LVO).

PATIENTS AND METHODS

Patient data were obtained from the national multicentre STAY ALIVE Acute Stroke Registry. At each centre, a team of vascular neurologists determined the TOAST classification. ENI was defined as a minimum 4-point decrease in the NIHSS score between admission and discharge, or a complete resolution of symptoms. For late functional outcome, we analysed the dichotomised 90-day mRS scores (good outcome was mRS≤2).

RESULTS

142 LAC and 156 CE patients were analysed. Following IVT, the percentage of ENI did not differ significantly (LAC 41.1% vs CE 49.7%, p=0.154), and multivariable analysis did not identify any clinical parameters that would predict ENI after IVT in either group. LAC patients had unfavourable, albeit non-significant, odds of having good 90-day functional outcomes compared to CE patients (aOR 0.483, 95% CI 0.201-1.161, p=104).

CONCLUSIONS

We report the first analysis of short- and long-term outcomes of IVT in LAC, using a homogenous control group of CE patients without LVO. The prevalence of ENI and 90-day functional outcomes were similar. However, LAC patients had unfavourable odds of achieving good functional outcomes compared to the control group. Therefore, we emphasise that LAC should not be considered a minor stroke subtype.

Stroke Incidence, Case Fatality, and Mortality Using the WHO International Classification of Diseases 11: The Geneva Stroke Study

BACKGROUND AND OBJECTIVES

In the field of stroke epidemiology, one of the major advances in the recently implemented International Classification of Diseases, 11th revision (ICD-11) relates to the definition of ischemic stroke, which now includes events shorter than 24 hours when ischemia can be proven on brain imaging. However, data are scarce to ascertain the incidence of strokes of short duration with tissue evidence of ischemia. In this study, we determined the incidence, 30-day case fatality, and mortality rate of stroke in the Geneva population using the new ICD-11 criteria, taking advantage of the organization of stroke service in the area.

METHODS

In this population-based observational cohort study, we used data from the Swiss Stroke Registry, supplemented by hospital records, outpatient medical files, and autopsy, to identify residents of the canton of Geneva, Switzerland, meeting the ICD-11 criteria for first-ever stroke, including ischemic strokes, nontraumatic intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH), from January 1, 2018, to December 31, 2019.

RESULTS

We identified 1,186 first-ever strokes (75.8 years [interquartile range 63.4-84.5]; 571 women [48.1%]). MRI was performed in 90.9% of patients with ischemic strokes. The annual incidence of first-ever stroke, age-adjusted to the European Standard Population, was 127.0/100,000 (95% CI 119.8-134.3) (107.3 [100.7-114.0] for ischemic stroke, 13.2 [10.9-15.5] for ICH, and 6.0 [4.4-7.5] for SAH [3.1 {2.0-4.2} for aneurysmal SAH]). Overall, the 30-day case fatality was higher in ICH (32.5% [95% CI 19.7-38.8], compared with SAH (17.2% [6.6-27.9] and ischemic strokes 10.8% [8.4-12.4]). The incidence of ischemic stroke was 107.3 (100.7-114.0) according to ICD-11 and 90.4 (84.3-96.5) according to ICD-10 (excluding patients with radiologic infarct and symptoms lasting <24 hours). Compared with ICD-10, ICD-11 increased the number of ischemic stroke cases by 18.3%. Patients with ischemic strokes identified with ICD-11 but not under ICD-10 (i.e., patients with symptoms lasting <24 hours and a brain lesion) were younger and presented with a lower National Institutes of Health Stroke Scale (NIHSS) score on admission compared with those identified by ICD-10 and ICD-11.

DISCUSSION

The new ICD-11 clinicoradiologic definition of ischemic stroke increased the number of ischemic stroke cases by 18.3% in our Western European population. Future studies will evaluate the impact of ICD-11 on the human, organizational, and economic needs allocated to the management of the disease.

Ethnicity as a Risk Factor for Early Neurological Deterioration: A Post Hoc Analysis of the Secondary Prevention of Small Subcortical Strokes Trial

OBJECTIVES

Nearly 25% of those with a small vessel stroke will develop early neurological deterioration (END). The objectives of this study were to identify clinical risk factors for small vessel stroke-related END and its associated impact on functional outcomes in an ethnically diverse data set.

METHODS

We performed a post hoc analysis of the "Secondary Prevention of Small Subcortical Strokes" trial. The primary outcome was END defined as progressive or stuttering stroke-related neurological symptoms. Standard descriptive and inferential statistical methods were used for analysis. Functional outcomes are reported by modified Rankin Scale score and analyzed by the Wilcoxon signed-rank test.

RESULTS

In all, 69 participants met the inclusion criteria; 21 (30%) had END. Of the cohort, Spanish, Hispanic, or Latino ethnicity (grouping per trial definition) most frequently developed END [11 (52.4%) vs 4 (8.3%), P < 0.001] with a higher adjusted likelihood of END (odds ratio: 14.1, 95% CI: 2.57-76.7, P = 0.002). Black or African-American race less commonly had END [3 (14.3%) vs 21 (43.8%), P = 0.03] but lost significance after adjustment (odds ratio: 1.46, 95% CI: 0.26-8.17, P = 0.67) due to powering. END was associated with a higher mean modified Rankin Scale (2.06 ± 0.94 vs 1.17 ± 0.79, P = 0.006) but did not differ in the shift analysis.

CONCLUSIONS

We found that Spanish, Hispanic, or Latino ethnicity was the most consistent risk factor for END though it was without meaningful functional outcome differences.

Advances in Cerebral Small Vessel Disease: Sandra E. Black Lecture to the Canadian Neurological Sciences Federation

Cerebral small vessel diseases (CSVDs) are among the most common age-related pathologies of the brain. Arteriolosclerosis and cerebral amyloid angiopathy (CAA) are the most common CSVDs. In addition to causing stroke and dementia, CSVDs can have diverse covert radiological manifestations on computed tomography and magnetic resonance imaging including lacunes, T2-weighted white matter hyperintensities, increased density of visible perivascular spaces, microbleeds and cortical superficial siderosis. Because they cannot be visualized directly, research on the pathophysiology of CSVD has been difficult. However, advances in quantitative imaging methods, including physiological imaging such as measurement of cerebrovascular reactivity and increased vascular permeability, are beginning to allow investigation of the early effects of CSVD in living people. Furthermore, genomics, metabolomics and proteomics have the potential to illuminate previously unrecognized pathways to CSVD that could be important targets for new clinical trials.

Defining short-term outcomes of minor ischemic stroke due to small artery occlusion in the era of dual antiplatelet treatment: A READAPT study sub-analysis

BACKGROUND

The outcomes of minor ischemic stroke resulting from small artery occlusion (SAO-MIS) have not yet been characterized after dual antiplatelet treatment (DAPT) has become the standard of care. We provided updated figures on the short-term prognosis of SAO-MIS treated with early short-term DAPT and compared the outcomes of SAO-MIS versus non-SAO-MIS patients.

METHODS

This is a prespecified sub-analysis from a prospective multicentric real-world study (READAPT, NCT05476081) including patients with minor (NIHSS≤5) non-cardioembolic ischemic stroke treated with DAPT. The primary outcome was a composite of 90-day symptomatic ischemic stroke or major cardiovascular events. Secondary outcomes were the 90-day ordinal distribution of modified Rankin Scale (mRS) scores, 90-day excellent functional outcome (mRS of 0 to 1), and 24-h early neurological deterioration (END). Safety outcomes were 90-day intracerebral hemorrhage, moderate-to-severe and any bleedings. All outcomes were compared between SAO-MIS and non-SAO-MIS patients.

RESULTS

We included 678 MIS, of whom 253 (37.3 %) were SAO-related. At 90 days, 3 patients with SAO-MIS had primary outcome (1.2 % [95 % CI 0.2 %-3.5 %]), which were all SAO-related ischemic strokes. For the secondary outcomes, most SAO-MIS patients (n = 191, 75.5 %) had 90-day excellent functional outcome and 12 had 24-h END (4.7 % [95 % CI 2.5 %-8.3 %]). Referring to safety outcomes, 90-day intracerebral hemorrhage occurred only in one patient with SAO-MIS (0.4 % [95 % CI 0.0 %- 2.2 %]). Compared to non-SAO-MIS, the 90-day risk of recurrent vascular events was significantly lower among SAO-MIS (aHR 0.24 [95 % CI 0.08-0.68]; p = 0.007), while there were not significant differences in other secondary outcomes, nor in the risk of safety events.

CONCLUSIONS

Our findings show overall favorable short-term prognosis after SAO-MIS treated with DAPT. Future studies should investigate factors associated with residual stroke risk and long-term outcomes of SAO-MIS.

Validation of a simple clinical tool for screening of acute lacunar stroke-A substudy of the WAKE-UP trial

INTRODUCTION

Lacunar stroke represents around a quarter of all ischemic strokes; however, their identification with computed tomography in the hyperacute setting is challenging. We aimed to validate a clinical score to identify lacunar stroke in the acute setting, independently, with data from the WAKE-UP trial using magnetic resonance imaging.

METHODS

We analyzed data from the WAKE-UP trial and extracted Oxfordshire Community Stroke Project (OCSP) classification. Lacunar score was defined by National Institutes of Health Stroke Scale (NIHSS) < 7 and OCSP lacunar syndrome. Assessment of lacunar infarct by two independent investigators was blinded to clinical data. We calculated sensitivity, specificity, negative and positive predictive value (NPV and PPV, respectively) of lacunar score.

RESULTS

We included 503 patients in the analysis, mean (±SD) age 65.2 (±11.6) years, 325 (65%) males, median (IQR) NIHSS = 6 (4-9); 108 (22%) lacunar infarcts were identified on magnetic resonance (MR), patients fulfilling lacunar score criteria were 120 (24%), of which 47 (44%) had a lacunar infarct. Lacunar score was negative in 322 (82%) of patients without lacunar infarct. Patients with lacunar score had lower NIHSS (4 vs 7, p < 0.001), higher systolic (157 vs 151 mmHg, p = 0.001) and diastolic (86 vs 83 mmHg, p = 0.013) blood pressure and smaller infarct volume (2.4 vs 9.5 mL, p < 0.001). Performance of lacunar score was as follows: sensitivity 0.44; specificity 0.82; PPV 0.39; NPV 0.84; and accuracy 0.73. Assuming a prevalence of lacunar stroke of 13%, PPV lowered to 0.30 but NPV was 0.90. Lacunar score performed better for supratentorial lacunar infarcts.

CONCLUSION

Lacunar score had a very good specificity and NPV for screening of lacunar stroke. Implementation of this simple tool into clinical practice may help hyperacute management and guide patient selection in clinical trials.

DATA ACCESS STATEMENT

Data supporting the results of this paper are available upon reasonable request to the corresponding author.

Cerebral blood flow and cognition after 3 months tadalafil treatment in small vessel disease (ETLAS-2): study protocol for a randomized controlled trial

BACKGROUND

Targeted treatment is highly warranted for cerebral small vessel disease, a causal factor of one in four strokes and a major contributor to vascular dementia. Patients with cerebral small vessel disease have impaired cerebral blood flow and vessel reactivity. Tadalafil is a specific phosphodiesterase 5 inhibitor shown to improve vascular reactivity in the brain.

METHODS

The ETLAS-2 trial is a phase 2 double-blind, randomized placebo-controlled, parallel trial with the feasibility of tadalafil as the primary outcome. The trial aims to include 100 patients with small vessel occlusion stroke or transitory ischemic attacks and signs of cerebral small vessel disease more than 6 months before administration of study medication. Patients are treated for 3 months with tadalafil 20 mg or placebo daily and undergo magnetic resonance imaging (MRI) to evaluate changes in small vessel disease according to the STandards for ReportIng Vascular changes on nEuroimaging (STRIVE) criteria as well as cerebral blood flow, cerebrovascular reactivity, and neurovascular coupling in a functional MRI sub-study. The investigation includes comprehensive cognitive testing using paper-pencil tests and Cambridge Neuropsychological Test Automated Battery (CANTAB) tests in a cognitive sub-study.

DISCUSSION

The ETLAS-2 trial tests the feasibility of long-term treatment with tadalafil and explores vascular and cognitive effects in cerebral small vessel disease in trial sub-studies. The study aims to propose a new treatment target and improve the understanding of small vessel disease. Currently, 64 patients have been included and the trial is estimated to be completed in the year 2024.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT05173896. Registered on 30 December 2021.

Differently Distributed Iron Deposition in Mild and Moderate Stroke with Small Artery Occlusion: A Pilot Voxel-Based Susceptibility Mapping Study

BACKGROUND

Small artery occlusion (SAO) is a common ischemic stroke subtype. However, its clinical outcome can be more severe than commonly understood. The severity of SAO can vary, ranging from mild to moderate. Iron deposition has been associated with the development and progression of stroke. However, its specific distribution and relationship with stroke severity in SAO remain unclear. The study's purpose is to investigate the differences in iron deposition between mild stroke with SAO (SAO-MiS) and moderate stroke with SAO (SAO-MoS) through quantitative susceptibility mapping (QSM) and its association with neurological deficits.

METHODS

Sixty-eight SAO participants within 24 hours of first onset were enrolled and separated into SAO-MiS and SAO-MoS according to the National Institutes of Health Stroke Scale (NIHSS) scores. QSM helped calculate the susceptibility maps, reflecting the iron content within the brain. The susceptibility maps were analyzed using voxel-wise statistical analysis to compare the iron deposition between SAO-MiS and SAO-MoS. Then, differentially distributed iron deposition helped differentiate between mild and moderate stroke using support vector machine (SVM) methods.

RESULTS

Compared with SAO-MiS, SAO-MoS depicted elevated iron deposition in the left pallidum, parahippocampal gyrus, and superior frontal gyrus medial region, and is lower in the right superior/middle frontal gyrus and bilateral supplementary motor area. Based on iron deposition, the SVM classifier's analysis revealed a high power to discriminate SAO-MoS from SAO-MiS. In addition, fibrinogen, triglyceride (TG), and total cholesterol (TC) were linked with QSM values in specific brain regions.

CONCLUSIONS

Our study first revealed the brain iron distribution after SAO and differently distributed iron deposition in SAO-MiS and SAO-MoS. The results indicate that iron deposition could play a role in the pathophysiology of SAO and its correlation with stroke severity.

Molecular Pathogenesis of Ischemic and Hemorrhagic Strokes: Background and Therapeutic Approaches

Stroke represents one of the neurological diseases most responsible for death and permanent disability in the world. Different factors, such as thrombus, emboli and atherosclerosis, take part in the intricate pathophysiology of stroke. Comprehending the molecular processes involved in this mechanism is crucial to developing new, specific and efficient treatments. Some common mechanisms are excitotoxicity and calcium overload, oxidative stress and neuroinflammation. Furthermore, non-coding RNAs (ncRNAs) are critical in pathophysiology and recovery after cerebral ischemia. ncRNAs, particularly microRNAs, and long non-coding RNAs (lncRNAs) are essential for angiogenesis and neuroprotection, and they have been suggested to be therapeutic, diagnostic and prognostic tools in cerebrovascular diseases, including stroke. This review summarizes the intricate molecular mechanisms underlying ischemic and hemorrhagic stroke and delves into the function of miRNAs in the development of brain damage. Furthermore, we will analyze new perspectives on treatment based on molecular mechanisms in addition to traditional stroke therapies.

Magnetically powered microwheel thrombolysis of occlusive thrombi in zebrafish

Tissue plasminogen activator (tPA) is the only FDA-approved treatment for ischemic stroke but carries significant risks, including major hemorrhage. Additional options are needed, especially in small vessel thrombi which account for ~25% of ischemic strokes. We have previously shown that tPA-functionalized colloidal microparticles can be assembled into microwheels (µwheels) and manipulated under the control of applied magnetic fields to enable rapid thrombolysis of fibrin gels in microfluidic models of thrombosis. Transparent zebrafish larvae have a highly conserved coagulation cascade that enables studies of hemostasis and thrombosis in the context of intact vasculature, clotting factors, and blood cells. Here, we show that tPA-functionalized µwheels can perform rapid and targeted recanalization in vivo. This effect requires both tPA and µwheels, as minimal to no recanalization is achieved with tPA alone, µwheels alone, or tPA-functionalized microparticles in the absence of a magnetic field. We evaluated tPA-functionalized µwheels in CRISPR-generated plasminogen (plg) heterozygous and homozygous mutants and confirmed that tPA-functionalized µwheels are dose-dependent on plasminogen for lysis. We have found that magnetically powered µwheels as a targeted tPA delivery system are dramatically more efficient at plasmin-mediated thrombolysis than systemic delivery in vivo. Further development of this system in fish and mammalian models could enable a less invasive strategy for alleviating ischemia that is safer than directed thrombectomy or systemic infusion of tPA.

FLAIR signal intensity ratio predicts small subcortical infarct early neurologic deterioration: a cross-sectional study

PURPOSE

Prior studies have used the fluid-attenuated inversion recovery sequence signal intensity ratio (FLAIR-SIR) to predict those with an incomplete infarct that may safely receive acute thrombolytics. Clinical early neurologic deterioration (END) of small subcortical infarcts (SSIs) is suspected to occur due to delayed infarct completion. We aimed to understand if a lower FLAIR-SIR, suggestive of an incomplete infarct, would have a higher likelihood of SSI-related END.

METHODS

A cross-sectional retrospective study was performed of those with an acute SSI (anterior or posterior circulation) without significant parent vessel steno-occlusive disease. END was defined as a new or worsened disabling neurologic deficit during the index hospitalization. Standard-of-care brain MRIs were reviewed from the hospitalization, and a FLAIR-SIR cutoff of ≤ 1.15 was used based on prior studies. Adjusted logistic regression models were used for analysis.

RESULTS

We identified 252 patients meeting inclusion criteria: median (IQR) age 68 (12) years, 38.5% (97/252) female, and 11% (28/252) with END. Tobacco use was more common in those without END (32%) compared with END (55%, p = 0.03). In adjusted analyses, a FLAIR-SIR cutoff of ≤ 1.15 yielded an odds ratio of 2.8 (95% CI 1.23-6.13, p = 0.012) of early neurological deterioration.

CONCLUSION

Those with a FLAIR-SIR ≤ 1.15 are nearly threefold more likely to develop SSI-related END.

Tirofiban combined with Aspirin in the Treatment of Acute Penetrating Artery Territory Infarction (STRATEGY): protocol for a multicentre, randomised controlled trial

BACKGROUND

Perforating artery territorial infarction (PAI) caused by branch atheromatous disease (BAD) is prone to recurrence and early progression without an effective and well-documented antiplatelet treatment regimen. Tirofiban, an adjunctive antiplatelet agent, has shown great potential to treat acute ischaemic stroke. However, whether the combination of tirofiban and aspirin can improve the prognosis of PAI remains unclear.

AIM

To explore an effective and safe antiplatelet regimen for reducing the risk of recurrence and early neurological deterioration (END) in PAI caused by BAD by comparing the tirofiban and aspirin combination with placebo and aspirin combination.

METHODS

Tirofiban combined with Aspirin in the Treatment of Acute Penetrating Artery Territory Infarction (STRATEGY) trial is an ongoing multicentre, randomised, placebo-controlled trial in China. Eligible patients shall be randomly assigned to receive standard aspirin with tirofiban or placebo on the first day and standard aspirin from days 2 to 90. The primary endpoint is a new stroke or END within 90 days. The primary safety endpoint is severe or moderate bleeding within 90 days.

DISCUSSION

The STRATEGY trial will assess whether tirofiban combined with aspirin is effective and safe in preventing recurrence and END in patients with PAI.

TRIAL REGISTRATION NUMBER

NCT05310968.

Sex differences in functional outcomes of intravenous thrombolysis among patients with lacunar stroke

Background

This study aimed to assess if there are sex differences in the functional outcome of intravenous thrombolysis (IVT) among patients with lacunar stroke (LS).

Methods

Consecutive patients admitted from 1 January 2014 to 31 January 2020 to hospitals participating in the Swiss Stroke Registry presenting with LS and treated with IVT were included. The study population was then divided into two groups based on patient sex, and a multivariable ordinal logistic regression analysis was performed to uncover sex differences in the modified Rankin Scale (mRS) score at 90 days after stroke.

Results

A total of 413 patients with LS were treated with IVT: 177 (42.9%) women and 236 (57.1%) men. Women were older than men (median age 74 years, 25th-75th percentiles 67-84 years versus 70 years, 25th-75th percentiles 60-80 years, value of p 0.001) and, after adjustment for meaningful variables, showed more frequently increased odds of a higher mRS score at 90 days after stroke (adjusted odds ratio 1.49, 95% confidence interval 1.01-2.19, value of p 0.044).

Conclusion

This study showed that female sex increased the odds of a worse functional response to IVT in patients with LS. Future studies should further elucidate the mechanisms underlying such sex differences.

Differences in characteristics between patients from Egypt and Germany presenting with lacunar stroke

Despite the enormous health burden of lacunar stroke, data from low- and middle-income countries on lacunar stroke characteristics and its comparison with that of high-income countries are scarce. Thus, we aimed to investigate and compare the variable characteristics and vascular status in patients from Egypt and Germany suffering lacunar stroke. Two cohorts of lacunar stroke patients from Ain Shams University Hospital, Egypt and Goethe University Hospital Frankfurt, Germany were retrospectively collected between January 2019 and December 2020 and analyzed for demographics, risk factors, mode of presentation, neuroimaging features, treatment protocols and outcomes. MRI showed a different distribution pattern of lacunar strokes between cohorts, detecting posterior circulation lacunar infarctions preponderantly in patients from Egypt and anterior circulation lacunar infarctions preponderantly in patients from Germany. Complementary MR/CT angiography revealed a significantly higher proportion of intracranial and combined intracranial and extracranial arterial stenosis in patients from Egypt than in patients from Germany, suggesting differences in pathological processes. Younger age, higher NIHSS on admission, and posterior circulation lacunar infarction were predictors of Egyptian origin, whereas hypertension was a predictor of German origin. Our results support the idea of clinical and neuroimaging phenotype variations in lacunar stroke, including different sources of lacunar stroke in patients of different populations and geographical regions. This implies that guidelines for management of lacunar stroke might be tailored to these differences accordingly.

Magnetically Powered Microwheel Thrombolysis of Occlusive Thrombi in Zebrafish

Tissue plasminogen activator (tPA) is the only FDA approved treatment for ischemic stroke but carries significant risks, including major hemorrhage. Additional options are needed, especially in small vessel thrombi which account for ~25% of ischemic strokes. We have previously shown that tPA-functionalized colloidal microparticles can be assembled into microwheels (µwheels) and manipulated under the control of applied magnetic fields to enable rapid thrombolysis of fibrin gels in microfluidic models of thrombosis. Providing a living microfluidic analog, transparent zebrafish larvae have a highly conserved coagulation cascade that enables studies of hemostasis and thrombosis in the context of intact vasculature, clotting factors, and blood cells. Here we show that tPA-functionalized µwheels can perform rapid and targeted recanalization in vivo. This effect requires both tPA and µwheels, as minimal to no recanalization is achieved with tPA alone, µwheels alone, or tPA-functionalized microparticles in the absence of a magnetic field. We evaluated tPA-µwheels in CRISPR-generated plasminogen (plg) heterozygous and homozygous mutants and confirmed that tPA-µwheels are dose-dependent on plasminogen for lysis. We have found that magnetically powered µwheels as a targeted tPA delivery system are dramatically more efficient at plasmin-mediated thrombolysis than systemic delivery in vivo. Further development of this system in fish and mammalian models could enable a less invasive strategy for alleviating ischemia that is safer than directed thrombectomy or systemic infusion of tPA.

Infarcts of a Cardioembolic Source Mimicking Lacunar Infarcts: Case Series With Clinical and Radiological Correlation

Lacunar strokes are the hallmark of cerebral small vessel disease. There are several well-established mechanisms for the pathogenesis of lacunar stroke, but the cardioembolic mechanism is not well-established. Three cases of acute ischemic stroke following elective cardiac and cerebral catheterization are reported. These cases had typical lacunar-looking infarcts on neuroimaging despite strong evidence of an embolic source with temporal correlation. Awareness of such findings and pathogenesis may help investigational workup and management of these patients.

The incidence of medium vessel occlusions: a population-based study

Introduction

The incidence of medium vessel occlusion (MeVO) is not well known. The objective of our study is to perform a population-based assessment to estimate the incidence of MeVOs.

Methods

Consecutive patients from Olmsted County, Minnesota who presented for acute ischemic stroke seen at Mayo Clinic Hospital from 1/1/2018 to 12/31/2020 who were found to have a MeVO were included in this study. MeVO was defined as occlusion at or beyond the level of the middle cerebral artery M2 segment, anterior cerebral artery A2 segment, posterior cerebral artery P1 segment, and cerebellar arteries. Census data for Olmsted County was obtained from the United States Census Bureau from the year 2020.

Results

A total of 1,718 patients were screened for the study, 77 patients fulfilled inclusion criteria to be included in the study. Presenting NIHSS was 9 (± 7). The population of Olmsted County was estimated to be 162,847. The incidence rate for MeVO was 16 cases (95% CI 12-19) per 100,000 people per year. Based on estimates of the US population in 2020 of 331,449,281 people, we estimate there are 52,236 (95% CI 40,635-64,002) new cases of MeVOs per year.

Conclusion

As the only stroke center in Olmsted County, we have been able to estimate the incidence of ischemic stroke due to MeVO. While the incidence of MeVOs is less than both large and small vessel occlusions, they still represent a significant proportion of strokes with significant morbidity and mortality that would benefit from further studies in both acute intervention and prevention.

Patterns of acute ischemic stroke and intracranial hemorrhage in patients with COVID-19 : Results of a retrospective multicenter neuroimaging-based study from three central European countries

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an infection which can affect the central nervous system. In this study, we sought to investigate associations between neuroimaging findings with clinical, demographic, blood and cerebrospinal fluid (CSF) parameters, pre-existing conditions and the severity of acute COVID-19.

MATERIALS AND METHODS

Retrospective multicenter data retrieval from 10 university medical centers in Germany, Switzerland and Austria between February 2020 and September 2021. We included patients with COVID-19, acute neurological symptoms and cranial imaging. We collected demographics, neurological symptoms, COVID-19 severity, results of cranial imaging, blood and CSF parameters during the hospital stay.

RESULTS

442 patients could be included. COVID-19 severity was mild in 124 (28.1%) patients (moderate n = 134/30.3%, severe n = 43/9.7%, critical n = 141/31.9%). 220 patients (49.8%) presented with respiratory symptoms, 167 (37.8%) presented with neurological symptoms first. Acute ischemic stroke (AIS) was detected in 70 (15.8%), intracranial hemorrhage (IH) in 48 (10.9%) patients. Typical risk factors were associated with AIS; extracorporeal membrane oxygenation therapy and invasive ventilation with IH. No association was found between the severity of COVID-19 or blood/CSF parameters and the occurrence of AIS or IH.

DISCUSSION

AIS was the most common finding on cranial imaging. IH was more prevalent than expected but a less common finding than AIS. Patients with IH had a distinct clinical profile compared to patients with AIS. There was no association between AIS or IH and the severity of COVID-19. A considerable proportion of patients presented with neurological symptoms first. Laboratory parameters have limited value as a screening tool.

Genotype-Guided Dual Antiplatelet Therapy in Minor Stroke or Transient Ischemic Attack With a Single Small Subcortical Infarction

BACKGROUND AND OBJECTIVES

Single small subcortical infarction (SSSI) is an important stroke subtype. The optimal antiplatelet medication for patients with ischemic stroke with an SSSI is still unclear. We aimed to test the efficacy and safety of ticagrelor-aspirin in preventing stroke recurrence among patients with SSSI in the Ticagrelor or Clopidogrel with Aspirin in High-Risk Patients with Acute Nondisabling Cerebrovascular Events II (CHANCE-2) trial.

METHODS

In the CHANCE-2 trial, patients with a minor stroke or TIA who carried CYP2C19 loss-of-function (LOF) alleles were randomly assigned within 24 hours after symptom onset, to either ticagrelor-aspirin (placebo clopidogrel plus a 180 mg loading dose of ticagrelor on day 1, followed by 90 mg twice daily on days 2-90) or clopidogrel-aspirin (placebo ticagrelor plus a 300 mg loading dose of clopidogrel on day 1, followed by 75 mg daily on days 2-90). Aspirin was applied during the first 21 days. Patients who had an SSSI (diffusion-weighted imaging lesion diameter ≤20 mm) were included in this analysis and further categorized into 2 types according to whether they had the responsible intracranial artery stenosis (ICAS): SSSI + ICAS and SSSI - ICAS. The primary efficacy outcome was a new stroke at 90 days.

RESULTS

Among 2,143 eligible patients, 340 had the responsible ICAS, and 1,803 did not. Ticagrelor-aspirin reduced stroke recurrence among all patients with SSSI (hazard ratio [HR]: 0.55; 95% CI 0.38-0.78; p = 0.001) compared with clopidogrel-aspirin. Stroke recurrence occurred in 35/901 (3.9%) patients with SSSI - ICAS on ticagrelor-aspirin and in 72/902 (8.0%) on clopidogrel-aspirin (hazard ratio [HR]: 0.45; 95% CI 0.29-0.68; p < 0.001). In patients with SSSI + ICAS, the corresponding event rates were 14/176 (8.0%) and 13/164 (7.9%), respectively (HR: 1.20; 95% CI 0.45-3.23; p = 0.71; p for interaction = 0.08). The risk of severe or moderate bleeding only occurred in patients with SSSI - ICAS (5/901 [0.6%] vs 5/902 [0.6%]).

DISCUSSION

In this prespecified substudy, ticagrelor-aspirin was superior to clopidogrel-aspirin in reducing the risk of stroke at 90 days among patients with SSSI who carried CYP2C19 LOF allele(s). Although there was no treatment-by-heterogeneous etiology interaction, a greater absolute risk reduction of stroke was observed in patients with SSSI - ICAS than in those with SSSI + ICAS.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that ticagrelor and aspirin reduced the risk of stroke recurrence compared with clopidogrel with aspirin in adult patients with acute minor SSSI.

Frailty and outcomes in lacunar stroke

BACKGROUND

Lacunar strokes (LS) are ischemic strokes of the small perforating arteries of deep gray and white matter of the brain. Frailty has been associated with greater mortality and attenuated response to treatment after stroke. However, the effect of frailty on patients with LS has not been previously described.

OBJECTIVE

To analyze the association between frailty and outcomes in LS.

METHODS

Patients with LS were selected from the National Inpatient Sample (NIS) 2016-2019 using the International Classification of Disease, 10^th edition (ICD-10) diagnosis codes. The 11-point modified frailty scale (mFI-11) was used to group patients into severely frail and non-severely frail cohorts. Demographics, clinical characteristics, and complications were defined. Health care resource utilization (HRU) was evaluated by comparing total hospital charges and length of stay (LOS). Other outcomes studied were discharge disposition and inpatient death.

RESULTS

Of 48,980 patients with LS, 10,830 (22.1%) were severely frail. Severely frail patients were more likely to be older, have comorbidities, and pertain to lower socioeconomic status categories. Severely frail patients with LS had worse clinical stroke severity and increased rates of complications such as urinary tract infection (UTI) and pneumonia (PNA). Additionally, severe frailty was associated with unfavorable outcomes and increased HRU.

CONCLUSION

Severe frailty in LS patients is associated with higher rates of complications and increased HRU. Risk stratification based on frailty may allow for individualized treatments to help mitigate adverse outcomes in the setting of LS.

Clinical Utility of the Transthoracic Echocardiogram for Isolated Lacunar Infarcts: A Single-Center Experience

BACKGROUND

Stroke is a prominent and financially burdensome disease. Lacunar strokes are traditionally attributed to small vessel disease rather than cardioemboli, which typically occlude larger arteries. Thus, the benefit of screening for potential sources of cardioemboli in lacunar stroke patients is unclear. We evaluated the clinical utility of the transthoracic echocardiogram performed in patients with lacunar strokes.

METHODS

A single-center retrospective analysis of ischemic stroke patients from January 2013 through December 2017 was performed. Brain magnetic resonance imaging was used to select patients with a single lacunar infarct. Patients presenting with acute symptoms of cardiac disease or an abnormal electrocardiogram were excluded. Transthoracic echocardiogram results were reviewed, and their utility in decision-making was evaluated.

RESULTS

Of the 442 patients at our institution diagnosed with ischemic stroke during the inclusion period, 89 met inclusion criteria. Transthoracic echocardiogram detected a patent foramen ovale in 5.6% of patients, mitral annular calcification in 9.0% of patients, and abnormal wall motion in 4.5% of patients. For all patients, there were no findings that prompted anticoagulation, antibiotic, or surgical intervention. The cost of an inpatient transthoracic echocardiogram is $4100, resulting in $364,900 in unnecessary health care spending.

CONCLUSIONS

Transthoracic echocardiogram appears to have minimal therapeutic value in most patients with lacunar strokes. In stroke patients with no acute symptoms of cardiac disease and a normal electrocardiogram, it may be reasonable to forgo the transthoracic echocardiogram if the brain magnetic resonance imaging shows an isolated lacunar infarct.

Genetic Study of Cerebral Small Vessel Disease in Chinese Han Population

Cerebral small vessel disease (CSVD) is a syndrome of clinical, neuroimaging, and neuropathological manifestations caused by disorders that affect small cerebral vessels. Although the pathogenesis of the disease remains unclear, some studies have demonstrated that genetic variants contribute to the development of CSVD. Our study aimed to explore the genetic characteristics of CSVD in the Chinese Han population. We enrolled 182 sporadic CSVD Chinese Han patients whose magnetic resonance imaging results showed grade 2-3 white matter lesions. Target region sequencing of seven monogenic CSVD-related genes, including NOTCH3, HTRA1, COL4A1, COL4A2, GLA, TREX1, and CTSA, was performed, and we identified pathogenic variants by screening the sequencing results and functional predictive analysis. All variants were predicted to be pathogenic by the SIFT Score, Polymorphism Phenotyping-2 score, Mutation Taster, Splice site score calculation, and MaxEntScan. All variants were validated in 300 healthy controls. In total, eight variants were identified in patients with CSVD, including five novel variants, c.1774C>T (NOTCH3), c.3784C>T (NOTCH3), c. 1207C>T (HTRA1), and c. 1274+1G> A (HTRA1), c.1937G>C (COL4A1) and three reported mutations. None of these variants were present in 300 healthy controls. No pathogenic variants in COL4A2, GLA, TREX1, and CTSA were detected. This study identified five novel variants in CSVD-related genes in Chinese Han patients with sporadic CSVD. Our results expand the genetic profile of CSVD.

Preliminary Findings on the Potential Use of Magnetic Resonance Elastography to Diagnose Lacunar Infarction

PURPOSE

Lacunar infarction is usually diagnosed by conventional technologies, such as CT and diffusion weighted imaging (DWI). To improve the accuracy of diagnosis, neurocognitive screening is still needed. Therefore, additional imaging methods that can assist and provide more accurate and rapid diagnostics are urgently needed. As an initial step towards potentially using MR elastography (MRE) for such diagnostic purposes, we tested the hypothesis that the mechanical properties of tissue in the vicinity of cerebral vasculature change following lacunar infarction in a way that can be quantified using MRE.

PATIENTS AND METHODS

MRE and MR angiography (MRA) images from 51 patients diagnosed with lacunar infarction and 54 healthy volunteers were acquired on a 3T scanner. All diagnoses were confirmed by matching neurocognitive test results to locations of flow obstruction in MRA. ROIs of the cerebral vessels segmented on the MRA images were mapped to the MRE images. Interpolation-based inversion was applied to estimate the regional biomechanical properties of ROIs that included cerebral vessels. The effects of lacunar infarction, sex, and age were analyzed using analysis of covariance (ANOCOVA).

RESULTS

Shear moduli over vessel ROIs were significantly lower for the lacunar infarction group than those of the healthy control group. A positive correlation between modulus over vessel ROIs and age was observed. However, no significant correlation was found between sex and the regional biomechanical properties of the vessel ROIs.

CONCLUSION

Results supported the hypothesis and suggest that biomechanical properties may be of utility in diagnosis of lacunar infarction.

Long-term mortality and recurrent vascular events in lacunar versus non-lacunar ischaemic stroke: A cohort study

Introduction

Studies of differences in very long-term outcomes between people with lacunar/small vessel disease (SVD) versus other types of ischaemic stroke report mixed findings, with limited data on myocardial infarction (MI). We investigated whether long-term mortality, recurrent stroke and MI risks differ in people with versus without lacunar/SVD ischaemic stroke.

Patients and methods

We included first-ever strokes from a hospital-based stroke cohort study recruited in 2002–2005. We compared risks of death, recurrent stroke and MI during follow-up among lacunar/SVD versus other ischaemic stroke subtypes using Cox regression, adjusting for confounding factors.

Results

We included 812 participants, 283 with lacunar/SVD ischaemic stroke and 529 with other stroke. During a median of 9.2 years (interquartile range 3.1–11.8), there were 519 deaths, 181 recurrent strokes and 79 MIs. Lacunar/SVD stroke was associated with lower mortality (adjusted HR 0.79, 95% CI 0.65 to 0.95), largely due to markedly lower all-cause mortality in the first year. From one year onwards this difference attenuated, with all-cause mortality only slightly and not statistically significantly lower in the lacunar/SVD group (0.86, 95% CI 0.70 to 1.05). There was no clear difference in risk of recurrent stroke (HR 0.84, 95% CI 0.61–1.15) or MI (HR 0.83, 95% CI 0.52–1.34).

Conclusion

Long-term risks of all-cause mortality, recurrent stroke and MI are similar, or only slightly lower, in patients with lacunar/SVD as compared to other ischaemic stroke. Patients and physicians should be as vigilant in optimising short- and long-term secondary prevention of vascular events in lacunar/SVD as for other stroke types.

Prevalence and Clinical Characteristics of Lacunar Stroke: A Hospital-Based Study

Lacunar stroke (LS) is responsible for one-quarter of the overall number of ischemic strokes with long-term complications and carries health and economic issues for patients and health care systems. Therefore, we aimed to investigate lacunar versus non-lacunar strokes in a tertiary academic center. From February 2016 to July 2019, all patients admitted to the stroke unit were retrospectively reviewed. We included LS patients and compared them to other TOAST subtypes. Hemorrhagic stroke and conditions mimicking stroke were excluded. Regression analysis was done to determine LS predictors and outcomes. A 35.5% rate of LS among 989 ischemic stroke patients was found. Most patients (71.9%) were males. Lower National Institutes of Health Stroke Scale (NIHSS) scores at admission and negative history for cardiac diseases were predictors for LS in our population. At discharge, LS patients had low NIHSS scores and shorter hospitalization periods compared to non-LS patients. In conclusion, LS was prevalent among ischemic stroke patients in our cohort. Future studies are highly needed with long follow-up intervals to identify the stroke recurrence, complications, and outcomes.

Pure Thalamic Infarct: 8-Year Follow-Up Study in a Hospital in China

Pure thalamic infarct is a rare lacunar stroke type, with little known about long-term outcomes. This 8-year, single-center, retrospective study evaluated the clinical background, etiology, Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification, and 8-year follow-up results in 27 patients with pure thalamic infarcts identified by MR diffusion-weighted imaging in Dalian, China. All patients presented chief complaints of limb weakness or sensory disturbances. Hypertension (24/27, 88.9%), diabetes (12/27, 44.4%), atrial fibrillation (1/27, 3.7%), hyperlipidemia (10/27, 37%), hyperhomocysteinemia (6/27, 22.2%), smoking history (10/27, 37%; 9/15, 60% for men; 1/12, 8.3% for women), and excessive alcohol consumption history (7/27, 25.9%; 7/15, 46.7% for men; 0 for women) were observed in our patient population. Based on TOAST classification, 1 patient had large artery atherosclerosis (7.14%), 23 had small vessel occlusion (SVO; 85.2%), and 3 patients were unidentified due to lack of cerebral angiography. The thalamic blood supply classification were as follows: 23 (85.2%), inferolateral territory; 1 (3.7%), tuberothalamic territory; 2 (7.4%), combination of tuberothalamic and paramedian arteries; 1 (3.7%), combination of inferolateral and paramedian arteries; 0, posterior choroidal arteries. During the 8-year follow-up, 3 patients died of colon cancer, multi-organ failure, and kidney failure, respectively; 7 presented with a recurrent stroke; while 10 recovered well with their risk factors under control. In conclusion, our cohort of pure thalamic infarcts were mainly due to SVO (TOAST), with hypertension as the main risk factor, and the inferolateral artery as the most implicated arterial territory. Less severe outcome or stroke recurrence are identified in long-term follow-up of pure thalamic infarcts. Other comorbidities would be cause of death in aged patients.

Blood supply to the corticospinal tract: A pictorial review with application to cranial surgery and stroke

The corticospinal tract (CST) is the main neural pathway responsible for conducting voluntary motor function in the central nervous system. The CST condenses into fiber bundles as it descends from the frontoparietal cortex, traveling down to terminate at the anterior horn of the spinal cord. The CST is at risk of injury from vascular insult from strokes and during neurosurgical procedures. The aim of this article is to identify and describe the vasculature associated with the CST from the cortex to the medulla. Dissection of cadaveric specimens was carried out in a manner, which exposed and preserved the fiber tracts of the CST, as well as the arterial systems that supply them. At the level of the motor cortex, the CST is supplied by terminal branches of the anterior cerebral artery and middle cerebral artery. The white matter tracts of the corona radiata and internal capsule are supplied by small perforators including the lenticulostriate arteries and branches of the anterior choroidal artery. In the brainstem, the CST is supplied by anterior perforating branches from the basilar and vertebral arteries. The caudal portions of the CST in the medulla are supplied by the anterior spinal artery, which branches from the vertebral arteries. The non-anastomotic nature of the vessel systems of the CST highlights the importance of their preservation during neurosurgical procedures. Anatomical knowledge of the CST is paramount to clinical diagnosis and treatment of heterogeneity of neurodegenerative, neuroinflammatory, cerebrovascular, and skull base tumors.

Acupuncture for patients recovering from lacunar infarction: A protocol for systematic review and meta-analysis

BACKGROUND

Lacunar infarction (LI) is the mild type in the classification of ischemic stroke, mostly occurs in the middle-aged and elderly, with mild hemiplegia and partial sensory disorder as the main manifestations. In the treatment of LI, acupuncture is often regarded as dominant therapy in the convalescence period. However, acupuncture for treatment of LI in the recovery period lacks high-quality reports and evidence-based medical evidence. Thus, we aim to evaluate the curative effect and safety of acupuncture for LI objectively.

METHODS

Pubmed, Cochrane Library, Web of Science, EBSCO, Springer, China National Knowledge Infrastructure, Chinese Scientific and Technical Journals Database (VIP), Wan-fang Database, Chinese Biomedical Literature Database, Chinese Science Citation Database, and other electronic databases will be retrieved from the inception to May, 2021. Randomized controlled trials related to this subject will be searched. The inclusion criteria are established and a detailed literature search strategy is designed through discussion. Article retrieval, screening, excluding repetitive studies, assessment of quality, and data processing will be conducted by 2 reviewers independently using EndNote (X9) and Review Manager (5.3.5). The outcome measures include primary outcome measures (total effective rate, National Institute of Health Stroke Scale score, and Fugl-Meyer Assessment score), secondary outcome measures (blood pressure, plasma glucose, and blood lipid), and safety outcome measures. We will perform a meta-analysis, descriptive analysis, and subgroup analysis based on data conditions.

RESULTS

The study of total effective rate, National Institute of Health Stroke Scale score, Fugl-Meyer Assessment score, blood pressure, plasma glucose, blood lipid, and adverse effects will provide evidenced outcome for high-quality synthesis and descriptive analysis.

CONCLUSION

This systematic review will kindly provide evidence of whether acupuncture is an effective and safe intervention for LI in the recovery period.

INPLASY REGISTRATION NUMBER

INPLASY202150060 (DOI:10.37766/inplasy2021.5.0060).

Lacunar stroke: mechanisms and therapeutic implications

Lacunar stroke is a marker of cerebral small vessel disease and accounts for up to 25% of ischaemic stroke. In this narrative review, we provide an overview of potential lacunar stroke mechanisms and discuss therapeutic implications based on the underlying mechanism. For this paper, we reviewed the literature from important studies (randomised trials, exploratory comparative studies and case series) on lacunar stroke patients with a focus on more recent studies highlighting mechanisms and stroke prevention strategies in patients with lacunar stroke. These studies suggest that lacunar stroke is a heterogeneous disease with various mechanisms, including most commonly lipohyalinosis and less commonly atheromatous disease and cardioembolism, highlighting the importance of a careful review of brain and neurovascular imaging, a cardiac and systemic evaluation. A better understanding of pathomechanisms of neurological deterioration may lead to investigating the utility of novel treatment strategies and optimisation of short-term antithrombotic treatment strategies to reduce the risk of neurological deterioration and prevent long-term disability in patients with lacunar stroke.

Reliability of Field Assessment Stroke Triage for Emergency Destination Scale Use by Paramedics: Mobile Stroke Unit First-Year Experience

[Figure: see text].

Large disparities in 28-day case fatality by stroke subtype: data from a French stroke registry between 2008 and 2017

BACKGROUND AND PURPOSE

The objectives of the present analysis were to assess 28-day stroke case fatality according to the stroke aetiology and to identify associated factors.

METHODS

All stroke events in adults aged ≥35 years between 2008 and 2017 were collected in a population-based stroke registry in northern France.

RESULTS

Out of a total of 2933 strokes, there were 479 (16%) haemorrhagic strokes and 2454 (84%) ischaemic strokes; the 28-day case fatality rates were 48% and 15%, respectively. Three-quarters of the 28-day case fatalities occurred within 6 days of the event for haemorrhagic strokes and within 16.5 days for ischaemic strokes. After an ischaemic stroke, the case fatality rate was higher for women (18%) than for men (12%, p < 0.0001); however, this difference disappeared after adjustment for age. Cardioembolic strokes (34%) and strokes of undetermined cause (33%) were the most common ischaemic subtypes, with case fatality rates of 16% and 18%, respectively. Large artery atherosclerosis (11%) and lacunar strokes (10%) were less common, and both types had a case fatality rate of 3%. Age at the time of the event and stroke severity were both significantly associated with case fatality. For some types of stroke, a history of cardiovascular events and residence in a nursing home were associated with a poor prognosis. Medical care in a neurology ward was inversely associated with case fatality, for all stroke subtypes.

CONCLUSIONS

In northern France, post-stroke case fatality remains high, especially for haemorrhagic stroke. Being treated in a neurology ward improved survival by around 80%.

Excessive Astrocytic GABA Causes Cortical Hypometabolism and Impedes Functional Recovery after Subcortical Stroke

Glucose hypometabolism in cortical structures after functional disconnection is frequently reported in patients with white matter diseases such as subcortical stroke. However, the molecular and cellular mechanisms have been poorly elucidated. Here we show, in an animal model of internal capsular infarct, that GABA-synthesizing reactive astrocytes in distant cortical areas cause glucose hypometabolism via tonic inhibition of neighboring neurons. We find that reversal of aberrant astrocytic GABA synthesis, by pharmacological inhibition and astrocyte-specific gene silencing of MAO-B, reverses the reduction in cortical glucose metabolism. Moreover, induction of aberrant astrocytic GABA synthesis by cortical injection of putrescine or adenovirus recapitulates cortical hypometabolism. Furthermore, MAO-B inhibition causes a remarkable recovery from post-stroke motor deficits when combined with a rehabilitation regimen. Collectively, our data indicate that cortical glucose hypometabolism in subcortical stroke is caused by aberrant astrocytic GABA and MAO-B inhibition and that attenuating cortical hypometabolism can be a therapeutic approach in subcortical stroke.

Association of genetic variants of RNF213 with ischemic stroke risk in Koreans

BACKGROUND

Large artery disease (LAD), cardioembolism (CE), and small vessel disease (SVD) are well-established causes of ischemic stroke. Although a founder variant of RNF213 has been regarded a genetic susceptibility for Moyamoya disease (MMD) and certain types of intracranial atherosclerotic stenosis (ICAS), correlations between RNF213 variants and ischemic stroke with SVD remain largely unknown.

OBJECTIVES

This study aimed to characterize the associations of four RNF213 polymorphisms (4448G>A, 4810G>A, 4863G>A, and 4950G>A) with ischemic stroke subtypes in Koreans.

METHODS

Genetic data from 529 stroke patients were analyzed and compared to 424 age- and sex-matched controls. Genetic variants of RNF213, as obtained from the Human Gene Mutation Database, were analyzed in the study subjects using the polymerase chain reaction restriction fragment length polymorphism assay. We investigated four single-nucleotide polymorphisms of RNF213 to elucidate their association with ischemic stroke [LAD, (n = 192), SVD (n = 145) and CE (n = 51)].

RESULTS

The RNF213 4950G>A genotype was observed more frequently in cerebral stroke patients and was more strongly associated with SVD than LAD (P = 0.014). RNF213 4448/4950 in combination with G-A was higher in SVD patients. However, the RNF213 4863/4950 allele combination was associated with increased risk of SVD and LAD. These results confirmed that RNF213 4950GA+AA variants were more frequent in ischemic stroke, especially in SVD, and that RNF213 G-G-G-A and G-G-G-A (4448/4810/4863/4950) haplotype sequences play a role in LAD and CE as well as SVD.

CONCLUSIONS

Our data reported that the RNF213 4950G>A genotypes and several RNF213 (4448/4810/4863/4950) haplotypes were associated with ischemic stroke in Koreans.

Impact of SMTP Targeting Plasminogen and Soluble Epoxide Hydrolase on Thrombolysis, Inflammation, and Ischemic Stroke

Stachybotrys microspora triprenyl phenol (SMTP) is a large family of small molecules derived from the fungus S. microspora. SMTP acts as a zymogen modulator (specifically, plasminogen modulator) that alters plasminogen conformation to enhance its binding to fibrin and subsequent fibrinolysis. Certain SMTP congeners exert anti-inflammatory effects by targeting soluble epoxide hydrolase. SMTP congeners with both plasminogen modulation activity and anti-inflammatory activity ameliorate various aspects of ischemic stroke in rodents and primates. A remarkable feature of SMTP efficacy is the suppression of hemorrhagic transformation, which is exacerbated by conventional thrombolytic treatments. No drug with such properties has been developed yet, and SMTP would be the first to promote thrombolysis but suppress disease-associated bleeding. On the basis of these findings, one SMTP congener is under clinical study and development. This review summarizes the discovery, mechanism of action, pharmacological activities, and development of SMTP.

Neuroinflammatory Mechanisms in Ischemic Stroke: Focus on Cardioembolic Stroke, Background, and Therapeutic Approaches

One of the most important causes of neurological morbidity and mortality in the world is ischemic stroke. It can be a result of multiple events such as embolism with a cardiac origin, occlusion of small vessels in the brain, and atherosclerosis affecting the cerebral circulation. Increasing evidence shows the intricate function played by the immune system in the pathophysiological variations that take place after cerebral ischemic injury. Following the ischemic cerebral harm, we can observe consequent neuroinflammation that causes additional damage provoking the death of the cells; on the other hand, it also plays a beneficial role in stimulating remedial action. Immune mediators are the origin of signals with a proinflammatory position that can boost the cells in the brain and promote the penetration of numerous inflammatory cytotypes (various subtypes of T cells, monocytes/macrophages, neutrophils, and different inflammatory cells) within the area affected by ischemia; this process is responsible for further ischemic damage of the brain. This inflammatory process seems to involve both the cerebral tissue and the whole organism in cardioembolic stroke, the stroke subtype that is associated with more severe brain damage and a consequent worse outcome (more disability, higher mortality). In this review, the authors want to present an overview of the present learning of the mechanisms of inflammation that takes place in the cerebral tissue and the role of the immune system involved in ischemic stroke, focusing on cardioembolic stroke and its potential treatment strategies.

A hospital-based study on ischaemic stroke characteristics, management, and outcomes in Sarawak: Where do we stand?

BACKGROUND

Located on the Borneo Island, Sarawak is the largest state of Malaysia and has a population distinctive from Peninsular Malaysia. The ischaemic stroke data in Sarawak had not been reported despite the growing number of patients annually. We aimed to investigate patient characteristics, management, and outcomes of ischaemic stroke in Sarawak and benchmark the results with national and international published data.

METHODS

We included ischaemic stroke cases admitted to Sarawak General Hospital between June 2013 and August 2018 from Malaysia National Stroke Registry. We performed descriptive analyses on patient demographics, cardiovascular risk factors, prior medications, smoking status, arrival time, thrombolysis rate, Get With The Guidelines (GWTG)-Stroke measures, and outcomes at discharge. We also numerically compared the results from Sarawak with the published data from selected national and international cohorts.

RESULTS

We analysed 1435 ischaemic stroke cases. The mean age was 60.1±13.2 years old; 64.9% were male; median baseline National Institute of Health Stroke Scale was seven points. Hypertension was the most prevalent risk factor of ischaemic stroke; 12.7% had recurrent stroke; 13.7% were active smokers. The intravenous thrombolysis rate was 18.8%. We achieved 80-90% in three GWTG-Stroke performance measures and 90-98% in four additional quality measures in our ischaemic stroke management. At discharge, 57% had modified Rankin Scale of 0-2; 6.7% died during hospitalisation. When compared with selected national and international data, patients in Sarawak were the youngest; Sarawak had more male and more first-ever stroke. Thrombolysis rate in Sarawak was higher compared with most studies in the comparison. Functional outcome at discharge in Sarawak was better than national cohort but still lagging behind when compared with the developed countries. In-hospital mortality rate in Sarawak was slightly lower than the national data but higher when compared with other countries.

CONCLUSION

Our study described characteristics, management, and outcomes of ischaemic stroke in Sarawak. We achieved high compliance with most of GTWG-Stroke performance and quality indicators. Sarawak had better outcomes than the national results on ischaemic stroke. However, there is still room for improvement when compared with other countries. Actions are needed to reduce the cardiovascular burdens for stroke prevention, enhance healthcare resources for stroke care, and improve intravenous thrombolysis treatment in Sarawak.

Recent glycemic control can predict the progressive motor deficits of acute subcortical infarction with diabetes or prediabetes

BACKGROUND AND PURPOSE

The predictors of progressive motor deficits in acute subcortical infarctions are still controversial. It is not known whether glycemic control influences on stroke progression.

METHODS

A total of 268 consecutive patients with diabetes or prediabetes who had acute (< 24 h) subcortical infarction were enrolled. (1) All patients were divided into 4 groups by quartile of glycated hemoglobin (HbA1c). (2) Only the patients with diabetes were divided by effective glycemic control. Progressive motor deficits were prospectively captured and defined as an increase of motor score ≥ 1 on the upper or lower limb items of the National Institute of Health Stroke Scale within 72 h from stroke onset.

RESULTS

Progressive motor deficits occur in 8/78 (10.3%) for ≤ 5.9, 15/61 (24.6%) for 6.0-6.4, 16/62 (25.8%) for 6.5-7.4, and 30/67 (44.8%) for ≥ 7.5. In diabetic patients alone, those occur in 5/37 (13.5%) for ≤ 6.5, 10/42 (23.8%) for 6.6-7.0, 12/42 (28.6%) for 7.1-8.0, and 24/50 (48.0%) for ≥ 8.1. An adjusted OR of progressive motor deficits was 2.61 (95% confidence interval [CI] 0.98-7.00, P = .056) for 6.0-6.4, 3.42 (95% CI 1.27-9.18, P = .015) for 6.5-7.4, and 6.65 (95% CI 2.38-18.62, P < .001) for ≥ 7.5. In diabetic patients alone, those were 3.15 (95% CI 0.89-11.15, P = .075) for 6.6-7.0, 2.90 (95% CI 0.79-10.61, P = .107) for 7.1-8.0, and 4.17 (95% CI 1.07-16.25, P = .038) for ≥ 8.1. The optimal cutoff value of HbA1c was 6.65% in discriminating progressive motor deficits.

CONCLUSION

Increased HbA1c was associated with higher incidence of progressive motor deficits in acute subcortical infarction with diabetes and prediabetes.

Tadalafil may improve cerebral perfusion in small-vessel occlusion stroke-a pilot study

New treatments for cerebral small-vessel disease are needed to reduce the risk of small-vessel occlusion stroke and vascular cognitive impairment. We investigated an approach targeted to the signalling molecule cyclic guanosine monophosphate, using the phosphodiesterase 5 inhibitor tadalafil, to explore if it improves cerebral blood flow and endothelial function in patients with cerebral small-vessel disease and stroke. In a randomized, double-blinded, placebo-controlled, cross-over pilot trial (NCT02801032), we included patients who had a previous (>6 months) small-vessel occlusion stroke. They received a single dose of either 20 mg tadalafil or placebo on 2 separate days at least 1 week apart. We measured the following: baseline MRI for lesion load, repeated measurements of blood flow velocity in the middle cerebral artery by transcranial Doppler, blood oxygen saturation in the cortical microvasculature by near-infrared spectroscopy, peripheral endothelial response by EndoPAT and endothelial-specific blood biomarkers. Twenty patients with cerebral small-vessel disease stroke (3 women, 17 men), mean age 67.1 ± 9.6, were included. The baseline mean values ± standard deviations were as follows: blood flow velocity in the middle cerebral artery, 57.4 ± 10.8 cm/s; blood oxygen saturation in the cortical microvasculature, 67.0 ± 8.2%; systolic blood pressure, 145.8 ± 19.5 mmHg; and diastolic blood pressure, 81.3 ± 9.1 mmHg. We found that tadalafil significantly increased blood oxygen saturation in the cortical microvasculature at 180 min post-administration with a mean difference of 1.57 ± 3.02%. However, we saw no significant differences in transcranial Doppler measurements over time. Tadalafil had no effects on peripheral endothelial function assessed by EndoPAT and endothelial biomarker results conflicted. Our findings suggest that tadalafil may improve vascular parameters in patients with cerebral small-vessel disease stroke, although the effect size was small. Increased oxygenation of cerebral microvasculature during tadalafil treatment indicated improved perfusion in the cerebral microvasculature, theoretically presenting an attractive new therapeutic target in cerebral small-vessel disease. Future studies of the effect of long-term tadalafil treatment on cerebrovascular reactivity and endothelial function are needed to evaluate general microvascular changes and effects in cerebral small-vessel disease and stroke.

Thrombolytic Therapy for Acute Ischemic Stroke: Past and Future

BACKGROUND

Thromboembolic ischemic stroke, which is mainly caused by hypertension, as well as plasma dyslipidemia, arterial fibrillation and diabetes, is a leading cause of death in the US and other countries. Numerous clinical trials for thrombolytic drugs, which aimed to pharmacologically dissolve thrombi, were conducted in the 1950s, when the first thrombolytic therapy was performed.

METHODS

In this study, we summarize the pathophysiologic features of ischemic stroke, and the history of thrombolytic therapy, and discuss the recent progress that has been made in the ongoing development of thrombolytic drugs.

CONCLUSION

Thrombolytic therapy is sometimes accompanied by harmful hemorrhagic insults; accordingly, a window of time wherein therapy can safely be performed has been established for this approach. Several basic and clinical studies are ongoing to develop next-generation thrombolytic drugs to expand the time window.

The Association of Autonomic Nervous System Function With Ischemic Stroke, and Treatment Strategies

Acute ischemic stroke, especially minor stroke, and transient ischemic attack have high risks of recurrence and exacerbation into severe ischemic strokes. It remains challenging to perform risk stratification and screen high-risk groups for initiation of early treatment in these patients. Moreover, with the growing population of patients with chronic small vessel disease, the mechanisms and clinical implications require further investigation. Traditional tools such as the ABCD2 score (age, blood pressure, clinical features, duration of symptoms, diabetes) have only moderate predictive value in patients with transient ischemic attack or minor stroke. By contrast, measurement of changes in heart rate variability (HRV) is an important and novel tool for risk stratification and outcome prediction in patients with cardiovascular diseases, as it reflects the overall level of autonomic nervous system dysfunction. Thus, abnormal HRV may be useful for prognosis and improve stratification of stroke patients with diverse risks. HRV may also partially explain autonomic nervous dysfunction and other manifestations during the process of chronic cerebral small vessel disease. In summary, measurement of HRV may contribute to early initiation of interventions in acute or chronic stroke patients using novel treatments involving rebalancing of autonomic nervous system function.

Nonarteritic anterior ischemic optic neuropathy is associated with cerebral small vessel disease

We investigated the presence of cerebral small vessel disease (SVD) in patients with nonarteritic anterior ischemic optic neuropathy (NAION) compared to control subjects without NAION to identify the association between NAION and cerebral SVD. We retrospectively reviewed the cases of 63 patients with NAION and 2749 control subjects without any neurologic and ocular diseases including NAION who underwent careful medical interviews, ophthalmic examinations, and magnetic resonance imaging (MRI) studies of the brain. We assessed and compared the degree of cerebral SVD on the MRIs. The patients with NAION presented with cerebral SVD more frequently than controls (68% versus 37%, respectively, p<0.001), which was also observed after adjusting for age, sex, comorbid conditions including hypertension, diabetes, and dyslipidemia, and smoking using the standardized mortality ratio (68% vs. 37%, p<0.001). A multivariate logistic regression analysis showed that the odds of cerebral SVD were 4.86 (95% CI, 2.10 to 11.24, p<0.001) times higher in patients with NAION than in the controls. We found that there was an association between cerebral SVD and NAION even after adjusting for age, sex, and medical histories. Clinicians should consider brain MRI scans in patients with NAION to prevent neurological impairment after cerebral SVD.

Genetic Factors of Cerebral Small Vessel Disease and Their Potential Clinical Outcome

Cerebral small vessel diseases (SVD) have been causally correlated with ischemic strokes, leading to cognitive decline and vascular dementia. Neuroimaging and molecular genetic tests could improve diagnostic accuracy in patients with potential SVD. Several types of monogenic, hereditary cerebral SVD have been identified: cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cathepsin A-related arteriopathy with strokes and leukoencephalopathy (CARASAL), hereditary diffuse leukoencephalopathy with spheroids (HDLS), COL4A1/2-related disorders, and Fabry disease. These disorders can be distinguished based on their genetics, pathological and imaging findings, clinical manifestation, and diagnosis. Genetic studies of sporadic cerebral SVD have demonstrated a high degree of heritability, particularly among patients with young-onset stroke. Common genetic variants in monogenic disease may contribute to pathological progress in several cerebral SVD subtypes, revealing distinct genetic mechanisms in different subtype of SVD. Hence, genetic molecular analysis should be used as the final gold standard of diagnosis. The purpose of this review was to summarize the recent discoveries made surrounding the genetics of cerebral SVD and their clinical significance, to provide new insights into the pathogenesis of cerebral SVD, and to highlight the possible convergence of disease mechanisms in monogenic and sporadic cerebral SVD.

IL-1α and IL-6 predict vascular events or death in patients with cerebral small vessel disease-Data from the SHEF-CSVD study

PURPOSE

The natural clinical course of cerebral small vessel disease (CSVD) was not thoroughly described. The aim of this single center cohort study was to establish biochemical predictors of vascular events and death in CSVD patients during a 24-month follow-up.

PATIENTS AND METHODS

A total of 130 functionally independent patients with marked MRI features of CSVD and recent lacunar stroke (n = 52,LS), vascular Parkinsonism (n = 28,VaP) or dementia (n = 50,VaD) were prospectively recruited. Serum markers of endothelial dysfunction, inflammation and hemostasis were determined at baseline. The primary outcome was defined as occurrence of death or any vascular events during the observation.

RESULTS

The mean age was 72 ± 8.1 years, and 37.6% of the patients were women. The mean follow-up time was 22.3 ± 4.3 months, and 84.6% of patients had extensive white matter lesions on baseline MRI. The overall mortality rate was 6.9%, and vascular events or death occurred in 27% of the patients. Kaplan-Meier survival curves revealed no significant differences between CSVD groups (log rank p = 0.49). Cox regression analysis revealed that IL-1α (HR 1.4; 95%CI 1.09-1.8), IL-6 (1.4;1.1-2.2), hs-CRP (1.1;1.06-1.9), homocysteine (1.4;1.1-1.8), fibrinogen (1.4;1.05-2), and d-dimer (2.7;1.6-4.5) were significantly associated with the primary outcome. IL-1α (1.3;1.07-1.8), IL-6 (1.4;1.02-2.2), d-dimer (2.8;1.6-5) and homocysteine (1.4;1.1-1.8) remained significant after adjusting for age, sex and CSVD radiological markers.

CONCLUSIONS

Our study demonstrated the important prognostic role of various circulation markers of inflammation in individuals with different clinical signs and radiological markers of CSVD. The strongest association occurred between IL-1α, IL-6 and recurrent stroke, other vascular events and death.

Clinical implications of extracellular vesicles in neurodegenerative diseases

Introduction: Extracellular vesicles (EVs) released by neural cells play a crucial role in intracellular communication in both physiological and pathological states. Recent studies have shown that the neuropathogenic manifestation of many progressive nervous system diseases including Parkinson's disease (PD), Alzheimer's diseases (AD), and amyotrophic lateral sclerosis (ALS). These diseases are frequently found to be associated with the accumulation of misfolded proteins, exploit EVs for the spread of aggregates to naive cells in a prion-like mechanism. Therefore, characterization of EVs and understanding their mechanism of action could open a window of opportunity to discover biomarkers and therapeutic targets in a disease-specific manner. Areas covered: In this review, we discuss the role of neural cells-derived EVs in normal and disease states. We also highlight their biomedical potential in modern medicine, including the use of circulating EVs as biomarkers for diagnosis with a special focus on newly-identified potential biomarkers in neurodegenerative disease, and novel methodologies in EVs isolation. Expert opinion: Systematic and comprehensive analysis of EVs in different biofluid sources is needed. Considering the potential for tremendous clinical benefits of EVs research in neurodegenerative disease, there is also an urgent need to standardize neural cells-derived EV enrichment protocols for consensus results.

Unilateral Perioral, Thumb, and Thenar Numbness Secondary to Acute Thalamic Infarct

Lacunar infarcts are small, deep infarcts that occur in subcortical regions of the brain and can result in pure sensory stroke syndromes, ataxia, and dysarthria. The most common predisposing etiology is small-vessel lipohyalinosis or microatheroma formation usually secondary to diabetes mellitus or systemic hypertension. We report a patient who presented with cheiro-oral syndrome (COS) with left sided perioral, thumb, and thenar numbness after an acute lacunar infarct of the right thalamus. 

Can we stop the stuttering in stroke? Interventions in 40 patients with acute lacunes

BACKGROUND

Whether any treatment can stop fluctuations of stuttering lacunar syndromes (SLS) is unclear. Case reports have variably suggested effectiveness of intravenous thrombolysis, dual antiplatelet treatment, blood pressure augmentation and anticoagulation. We aim to describe our experience with different treatments used in in patients presenting with SLS and their effect on clinical fluctuations and functional outcome.

METHODS

We collected demographic and clinical data of consecutive adult patients with SLS. Descriptive summaries were reported as median and inter-quartile range (IQR) for continuous variables and as frequencies and percentages for categorical variables.

RESULTS

Forty patients (72 ± 10 years, 36% female) were included. Pure motor syndrome (57%) was the most frequent clinical presentation. Clinical fluctuations stopped and the improvement was temporally related to aspirin-clopidogrel in 11/17 cases, intravenous thrombolysis in 4/6 cases, blood pressure augmentation in 1/3 cases and aspirin in 1/7 cases. Two patients continued fluctuating after IVT and later responded to blood pressure augmentation (n = 1) or aspirin-clopidogrel (n = 1).

CONCLUSIONS

Aspirin plus clopidogrel may be followed by clinical improvement when intravenous thrombolysis is not an option. Blood pressure augmentation may beneficial as ad-on treatment in patients with labile blood pressure.