Pharmacological Modulation of Neutrophil Extracellular Traps Reverses Thrombotic Stroke tPA (Tissue-Type Plasminogen Activator) Resistance.

Background and Purpose- Recanalization of the occluded artery is a primary goal in stroke treatment. Unfortunately, endovascular treatment is not always available, and tPA (tissue-type plasminogen activator) therapy is limited by its narrow therapeutic window; importantly, the rate of early arterial recanalization after tPA administration is low, especially for platelet-rich thrombi. The mechanisms for this tPA resistance are not well known. Since neutrophil extracellular traps (NETs) have been implicated in this setting, our aim was to study whether NET pharmacological modulation can reverse tPA resistance and the role of TLR4 (Toll-like receptor 4), previously related to NET formation, in thrombosis. Methods- To this goal, we have used a mouse photothrombotic stroke model, which produces a fibrin-free thrombus composed primarily of aggregated platelets and thrombi obtained from human stroke patients. Results- Our results demonstrate that (1) administration of DNase-I, which promotes NETs lysis, but not of tPA, recanalizes the occluded vessel improving photothrombotic stroke outcome; (2) a preventive treatment with Cl-amidine, impeding NET formation, completely precludes thrombotic occlusion; (3) platelet TLR4 mediates NET formation after photothrombotic stroke; and (4) ex vivo fresh platelet-rich thrombi from ischemic stroke patients are effectively lysed by DNase-I. Conclusions- Hence, our data open new avenues for recanalization of platelet-rich thrombi after stroke, especially to overcome tPA resistance.

Iron Overload Exacerbates the Risk of Hemorrhagic Transformation After tPA (Tissue-Type Plasminogen Activator) Administration in Thromboembolic Stroke Mice.

Background and Purpose- Recanalization with tPA (tissue-type plasminogen activator) is the only pharmacological therapy available for patients with ischemic stroke. However, the percentage of patients who may receive this therapy is limited by the risk of hemorrhagic transformation (HT)-the main complication of ischemic stroke. Our aim is to establish whether iron overload affects HT risk, to identify mechanisms that could help to select patients and to prevent this devastating complication. Methods- Mice fed with control or high-iron diet were subjected to thromboembolic stroke, with or without tPA therapy at different times after occlusion. Blood samples were collected for determination of malondialdehyde, matrix metalloproteinases, and fibronectin. Brain samples were collected 24 hours after occlusion to determine brain infarct and edema size, hemorrhage extension, IgG extravasation, and inflammatory and oxidative markers (neutrophil infiltration, 4-hydroxynonenal, and matrix metalloproteinase-9 staining). Results- Despite an increased rate of recanalization, iron-overload mice showed less neuroprotection after tPA administration. Importantly, iron overload exacerbated the risk of HT after early tPA administration, accelerated ischemia-induced serum matrix metalloproteinase-9 increase, and enhanced basal serum lipid peroxidation. High iron increased brain lipid peroxidation at most times and neutrophil infiltration at the latest time studied. Conclusions- Our data showing that iron overload increases the death of the compromised tissues, accelerates the time of tPA-induced reperfusion, and exacerbates the risk of HT may have relevant clinical implications for a safer thrombolysis. Patients with stroke with iron overload might be at high risk of HT after fibrinolysis, and, therefore, clinical studies must be performed to confirm our results.

Prognosis of Tandem Occlusions versus Isolated Intracranial Occlusions.

BACKGROUND: Both acute single intracranial and tandem occlusions are managed with intravascular thrombectomy with success, but little evidence exists about the differences in their mid-term outcome. We aim to compare the outcome at 3 months after tandem (extracranial internal carotid and/or middle cerebral artery) and single intracranial (M1 division) occlusions, and to identify the factors, which determine such prognosis. METHODS: A total of 66 patients (33 with tandem and 33 with singleM1 occlusions) who underwent emergent intravascular therapy in our center between November of 2013 and November of 2016 were collected. Patients' medical histories were reviewed for clinical and radiological variables. A modified Rankin Scale of 3 or more was considered as bad outcome. An interobserver concordance analysis evaluated the quality of collaterals in the initial computed tomography through the Maas, Miteff, and CGS (collateral grading scale) scales. RESULTS: No differences were found in theprognosis of tandem versus single M1 occlusions (P = .30). The kappa index for the Maas scale was .77 (95% confidence interval [CI] .59-.94) and bad collaterals were defined by a score of 1 or 2. The factors independently associated with a worse prognosis were the presence of bad collaterals (adjusted odds ratio [OR] 6.03, 95% CI 1.01-35.9, P = .048) and an incomplete revascularization (adjusted OR 6.01, 95% CI 1.01-35.7, p = .049). CONCLUSIONS: The outcome of patients with acute stroke secondary to tandem or M1 occlusions has not been found to depend on their localization. The bad quality of collaterals is the main factor related to an unfavorable prognosis.

Toll-Like Receptor 4 Mediates Hemorrhagic Transformation After Delayed Tissue Plasminogen Activator Administration in In Situ Thromboembolic Stroke.

BACKGROUND AND PURPOSE: Hemorrhagic transformation is the main complication of revascularization therapies after stroke. Toll-like receptor 4 (TLR4) is implicated in cerebral damage and inflammation in stroke. This study was designed to determine the role of TLR4 in hemorrhagic transformation development after tissue plasminogen activator (tPA) administration. METHODS: Mice expressing (TLR4+/+) or lacking functional TLR4 (TLR4-/-) were subjected to middle cerebral artery occlusion using an in situ thromboembolic model by thrombin injection into the middle cerebral artery, and tPA (10 mg/kg) was administered 20 minutes or 3 hours after ischemia. Infarct size, hemorrhages, IgG extravasation, matrix metalloproteinase 9 expression, and neutrophil infiltration were assessed 24 hours after ischemia. RESULTS: In TLR4+/+, early reperfusion (tPA at 20 minutes) resulted infarct volume, whereas late recanalization (tPA at 3 hours) did not modify lesion size and increased the rate of the most severe hemorrhages. In TLR4-/- mice, both early and late reperfusion did not modify lesion size. Importantly, late tPA administration did not result in worse hemorrhages and in an increased bleeding area as occurred in TLR4+/+ group. In TLR4-/- animals, late reperfusion produced a lesser increase in matrix metalloproteinase 9 expression when compared with TLR4+/+ animals. CONCLUSIONS: Our results demonstrate TLR4 involvement in hemorrhagic transformation induced by delayed tPA administration, very likely by increasing matrix metalloproteinase 9 expression.

Stroke and transient ischemic attack incidence rate in Spain: the IBERICTUS study.

BACKGROUND: In Spain, stroke is a major public health concern, but large population-based studies are scarce and date from the 1990s. We estimated the incidence and in-hospital mortality of stroke through a multicentered population-based stroke register in 5 geographical areas of Spain, i.e. Lugo, Almería, Segovia, Talavera de la Reina and Mallorca, representing north, south, central (×2) and Mediterranean areas of Spain, respectively, the aim and novelty being that all methodologies were standardized, and diagnoses were verified by a neurologist using neuroimaging techniques. METHODS: The register identified subjects >17 years of age who suffered a first-ever stroke or transient ischemic attack (TIA) between 1 January and 31 December 2006. Stroke and TIA were defined according to the WHO criteria. The Lausanne Stroke Registry definitions were used to classify ischemic stroke subtypes, as follows: (1) large-artery atherosclerosis (LAA); (2) cardioembolism (CE); (3) lacunar stroke or small-artery occlusion (SAO); (4) stroke of other infrequent cause (SIC), and (5) stroke of undetermined cause (UND). We used several complementary data sources such as hospital discharge registers, emergency room registers and primary care surveillance systems. RESULTS: In the 1-year study period, we identified 2,700 first-ever cerebrovascular episodes (53% men; 2,257 strokes + 443 TIA episodes). Brain CT in the acute stage was performed in 99% of cases. Of a total of 2,257 stroke patients, 1,817 (81%) had cerebral infarction, 350 (16%) had intracerebral hemorrhage, 59 (3%) had subarachnoid hemorrhage (SAH) and 31 (1%) had unclassifiable stroke. The overall unadjusted annual incidence for all cerebrovascular events was 187 per 100,000 [95% confidence interval (CI) 180-194; incidence for men: 202, 95% CI 189-210; incidence for women: 187, 95% CI 180-194]. The subtype of ischemic stroke could be determined in 1,779 patients and was classified as LAA in 624 (35%), CE in 352 (20%), SAO in 316 (18%), SIC in 56 (3%) and UND in 431 (24%). The incidence rates per 100,000 (95% CI) standardized to the 2006 European population were as follows: all cerebrovascular events, 176 (169-182); all stroke (non-TIA), 147 (140-153); TIA, 29 (26-32); ischemic stroke, 118 (112-123); intracerebral hemorrhage, 23 (21-26), and SAH, 4.2 (3.1-5.2). Incidence rates clearly increased with age in both genders, with a peak at or above 85 years of age. The in-hospital mortality was 14%. CONCLUSIONS: Our results show that the incidence of stroke and TIA in Spain is moderate compared to other Western and European countries. However, it is expected that these figures will change due to progressively aging populations.

Epidemiology of atrial fibrillation-related ischemic stroke and its association with DOAC uptake in Spain: first national population-based study 2005 to 2018.

INTRODUCTION AND OBJECTIVES: The incidence and prevalence of atrial fibrillation (AF), a major risk factor for stroke, has increased substantially in the past few years. However, several studies have reported a decline in AF-related stroke rates associated with higher uptake of direct oral anticoagulants (DOACs). This ecological study evaluated the association between DOAC uptake in Spain and the incidence rate (IR) of AF-related ischemic stroke. METHODS: Data were obtained from the Registry of Activity of Specialized Healthcare of the Spanish Ministry of Health (RAE-MDS). AF-related ischemic strokes were identified using International Classification of Diseases codes. IR were age-standardized and adjusted to the 2013 European standard population. Poisson regression models were used to identify the association between DOAC uptake and AF-related ischemic stroke in patients aged ≥ 65 years. RESULTS: Before the use of DOACs, the adjusted IR of AF-related ischemic stroke increased steadily from 2005 (IR=2.20 per 100 000 person/y) to 2012 (IR=2.67). Upon DOAC uptake in Spain from 2012 onwards for AF-related ischemic stroke prevention, the IR remained constant or decreased slightly (IR in 2018=2.66). Poisson regression showed that DOAC uptake was a significant predictor for the rate of AF-related ischemic stroke in patients older than 65 years (IRR=0.995; 95%CI, 0.995-0.996). CONCLUSIONS: This study shows an association between DOAC use and a reduced incidence of AF-related ischemic stroke. While this association is based on aggregate data and cannot demonstrate causality, these findings suggest that higher DOAC uptake could improve health outcomes in AF patients in Spain.

Hereditary cerebral small vessel disease: Assessment of a HTRA1 variant using protein stability predictors and 3D modelling.

Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is an autosomal recessive vascular disorder caused by biallellic variants in HTRA1. Recently, it has been reported that several heterozygous mutations in HTRA1 are responsible for a milder late-onset cerebral small vessel disease (CSVD) with an autosomal dominant pattern of inheritance. The majority of them are missense that affects the Htr1A protease activity due to a dominant-negative effect caused by defective trimerization or monomer activation. The molecular mechanism related to the structural destabilization of the protein supports the practical utility of integrating computational stability predictors to prioritize candidate variants in this gene. In this work, we report a family with several members diagnosed with subcortical ischemic events and progressive cognitive impairment caused by the novel c.820C > G, p.(Arg274Gly) heterozygous variant in HTRA1 segregating in an autosomal dominant manner and propose its molecular mechanism by a three-dimensional model of the protein's structure.

Prehospital selection of thrombectomy candidates beyond large vessel occlusion: M-DIRECT scale.

OBJECTIVE: Current prehospital scales used to detect large vessel occlusion reveal very low endovascular thrombectomy (EVT) rates among selected patients. We developed a novel prehospital scale, the Madrid-Direct Referral to Endovascular Center (M-DIRECT), to identify EVT candidates for direct transfer to EVT-capable centers (EVT-Cs). The scale evaluated clinical examination, systolic blood pressure, and age. Since March 2017, patients closer to a stroke unit without EVT capabilities and an M-DIRECT positive score have been transferred to the nearest EVT-C. To test the performance of the scale-based routing protocol, we compared its outcomes with those of a simultaneous cohort of patients directly transferred to an EVT-C. METHODS: In this prospective observational study of consecutive patients with stroke code seen by emergency medical services, we compared diagnoses, treatments, and outcomes of patients who were closer to an EVT-C (mothership cohort) with those transferred according to the M-DIRECT score (M-DIRECT cohort). RESULTS: The M-DIRECT cohort included 327 patients and the mothership cohort 214 patients. In the M-DIRECT cohort, 227 patients were negative and 100 were positive. Twenty-four (10.6%) patients required secondary transfer, leaving 124 (38%) patients from the M-DIRECT cohort admitted to an EVT-C. EVT rates were similar for patients with ischemic stroke in both cohorts (30.9% vs 31.5%). The M-DIRECT scale had 79% sensitivity, 82% specificity, and 53% positive predictive value for EVT. Recanalization and independence rates at 3 months did not differ between the cohorts. CONCLUSIONS: The M-DIRECT scale was highly accurate for EVT, with treatment rates and outcomes similar to those of a mothership paradigm, thereby avoiding EVT-C overload with a low rate of secondary transfers.

Myeloid cells as therapeutic targets in neuroinflammation after stroke: Specific roles of neutrophils and neutrophil-platelet interactions.

Ischemic brain injury causes a local inflammatory response, involving the activation of resident brain cells such as microglia and the recruitment of infiltrating immune cells. Increasing evidence supports that plasticity of the myeloid cell lineage is determinant for the specific role of these cells on stroke outcome, from initiation and maintenance to resolution of post-ischemic inflammation. The aim of this review is to summarize some of the key characteristics of these cells and the mechanisms for their recruitment into the injured brain through interactions with platelets, endothelial cells and other leukocytes. Also, we discuss the existence of different leukocyte subsets in the ischemic tissue and, specifically, the impact of different myeloid phenotypes on stroke outcome, with special emphasis on neutrophils and their interplay with platelets. Knowledge of these cellular phenotypes and interactions may pave the way to new therapies able to promote protective immune responses and tissue repair after cerebral ischemia.

Test repositioning for functional assessment of neurological outcome after experimental stroke in mice.

Stroke is a cerebrovascular pathology for which the only approved treatment is fibrinolysis. Several studies have focused on the development of new drugs but none has led to effective therapies to date, due, among others, to the difficulty to evaluate clinical deficits in experimental animal models. The present study aims to explore the applicability of known behavioral tests not commonly used in ischemia for the neurological assessment of mice after experimental stroke in different brain areas. A total of 225 CD1 male mice were randomly assigned to permanent middle cerebral artery occlusion by ligature (pMCAO) or permanent anterior cerebral artery occlusion by photothrombosis (pACAO) models. Modified neuroseverity score, footprint test, forced swim test and elevated plus maze were performed. Under these experimental conditions, modified neuroseverity score showed neurological impairment early after experimental stroke in both models. By contrast, the footprint test and the elevated plus maze detected short-term neurological deterioration in the pMCAO model but not in the pACAO model. Furthermore, the forced swim test identified depression-like behavior in mice after ischemia only when the left hemisphere was affected. In conclusion, we propose the repositioning of known neurobehavioral tests, but not commonly used in the stroke field, for the fast detection of neurological impairments early after ischemia, and even specific to discriminate the territory affected by arterial occlusion as well as the hemisphere where brain damage occurs. All these findings may prove useful to improve the experimental design of neuroprotective drugs in order to bridge the gap between experimental studies and clinical trials.

Stroke prevalence among the Spanish elderly: an analysis based on screening surveys.

BACKGROUND: This study sought to describe stroke prevalence in Spanish elderly populations and compare it against that of other European countries. METHODS: We identified screening surveys--both published and unpublished--in Spanish populations, which fulfilled specific quality requirements and targeted prevalence of stroke in populations aged 70 years and over. Surveys covering seven geographically different populations with prevalence years in the period 1991-2002 were selected, and the respective authors were then asked to provide descriptions of the methodology and raw age-specific data by completing a questionnaire. In addition, five reported screening surveys in European populations furnished useful data for comparison purposes. Prevalence data were combined, using direct adjustment and logistic regression. RESULTS: The overall study population, resident in central and north-eastern Spain, totalled 10,647 persons and yielded 715 cases. Age-adjusted prevalences, using the European standard population, were 7.3% for men, 5.6% for women, and 6.4% for both sexes. Prevalence was significantly lower in women, OR 0.79 95% CI 0.68-0.93, increased with age, particularly among women, and displayed a threefold spatial variation with statistically significant differences. Prevalences were highest, 8.7%, in suburban, and lowest, 3.8%, in rural populations. Compared to pooled Spanish populations, statistically significant differences were seen in eight Italian populations, OR 1.39 95% CI (1.18-1.64), and in Kungsholmen, Sweden, OR 0.40 95% CI (0.27-0.58). CONCLUSION: Prevalence in central and north-eastern Spain is higher in males and in suburban areas, and displays a threefold geographic variation, with women constituting the majority of elderly stroke sufferers. Compared to reported European data, stroke prevalence in Spain can be said to be medium and presents similar age- and sex-specific traits.

Intracranial internal carotid artery angioplasthy and stenting in giant cell arteritis.

We report the case of a 59-year-old woman who presented with several episodes of transient ischemic attack (TIA) caused by pathologically confirmed giant cell arteritis. She continued suffering from TIAs during admission despite immunosuppressant and antithrombotic therapy. Sudden neurological deterioration with paraparesis and cognitive impairment developed. A brain magnetic resonance (MR) imaging showed bilateral watershed ischemic lesions. MR angiography demonstrated severe stenosis of both intracranial internal carotid arteries (ICAs). Angioplasty and stenting on the left ICA were performed, with evident clinical improvement occurring within 24 hours. Endovascular therapy may be an alternative option to treat severe GCA with symptomatic intracranial large vessel disease not responsive to intensive conventional medical treatment.

The national burden of cerebrovascular diseases in Spain: a population-based study using disability-adjusted life years.

BACKGROUND AND OBJECTIVE: The aim of the present study was to determine the national burden of cerebrovascular diseases in the adult population of Spain. PATIENTS AND METHODS: Cross-sectional, descriptive population-based study. We calculated the disability-adjusted life years (DALY) metric using country-specific data from national statistics and epidemiological studies to obtain representative outcomes for the Spanish population. DALYs were divided into years of life lost due to premature mortality (YLLs) and years of life lived with disability (YLDs). DALYs were estimated for the year 2008 by applying demographic structure by sex and age-groups, cause-specific mortality, morbidity data and new disability weights proposed in the recent Global Burden of Disease study. In the base case, neither YLLs nor YLDs were discounted or age-weighted. Uncertainty around DALYs was tested using sensitivity analyses. RESULTS: In Spain, cerebrovascular diseases generated 418,052 DALYs, comprising 337,000 (80.6%) YLLs and 81,052 (19.4%) YLDs. This accounts for 1,113 DALYs per 100,000 population (men: 1,197 and women: 1,033) and 3,912 per 100,000 in those over the age of 65 years (men: 4,427 and women: 2,033). Depending on the standard life table and choice of social values used for calculation, total DALYs varied by 15.3% and 59.9% below the main estimate. CONCLUSIONS: Estimates provided here represent a comprehensive analysis of the burden of cerebrovascular diseases at a national level. Prevention and control programmes aimed at reducing the disease burden merit further priority in Spain.

Cerebrovascular disease incidence in central Spain (NEDICES): a population-based prospective study.

BACKGROUND: Stroke is one of the most disabling and burdensome health conditions worldwide, but no prospective population-based study has been conducted in Spain. Our aim was to assess age- and gender incidence rates of cerebrovascular disease, including stroke and transient ischemic attack, in three populations in central Spain using data from the NEDICES (Neurological Diseases in Central Spain), a population-based survey of elderly participants. METHODS: Individuals were evaluated at baseline (1994-1995) and at follow-up (a median of 3.2 years later in 1997-1998). The evaluation included a screening questionnaire for stroke and a neurological assessment (when possible). RESULTS: Of 5278 participants evaluated at baseline, there were 257 prevalent stroke cases. Seventy-five incident patients with cerebrovascular disease (57 stroke cases and 18 transient ischemic attacks cases) were identified among 3914 individuals assessed at follow-up. Average annual incidence rate (per 1000 person-years) in the population aged 65 to 85 and over years, adjusted to the standard European population, was 5.1 (95% CI, 3.7 to 6.6) for all types of cerebrovascular disease. Age-specific incidence rates of cerebrovascular disease increased with advancing age. Age and diabetes mellitus were independent risk factors for cerebrovascular disease. Number of vascular risk factors present at baseline showed an independent positive and graded association with incident cerebrovascular disease. CONCLUSIONS: In the NEDICES study, incidence of cerebrovascular disease increased with age beyond age 85. Our incidence rates provide new estimates for projection of future burden of disease in Spain.

[Fluctuating ptosis as the presenting symptom of spontaneous liquoral hypotension syndrome]. / Ptosis fluctuante como presentación del síndrome de hipotensión licuoral espontánea.

TITLE: Ptosis fluctuante como presentacion del sindrome de hipotension licuoral espontanea.