Intravenous Thrombolysis After First-Ever Ischemic Stroke and Reduced Incident Dementia Rate

Prognostic Models of Mortality Following First-Ever Acute Ischemic Stroke: A Population-Based Retrospective Cohort Study

Background and Aims

There is a lack of population-based studies focusing on guideline-based prognostic models for stroke. This study aimed to develop and validate a prognostic model that predicts mortality following a first-ever acute ischemic stroke.

Methods

The study included 899 adult patients ( ≥ 18 years) with confirmed diagnosis of first-ever acute ischemic stroke enrolled in the Malaysian National Stroke Registry (NSR) from January 2009 to December 2019. The primary outcome was mortality within 90 days post-stroke (266 events [29.6%]). The prognostic model was developed using logistic regression (75%, n = 674) and internally validated (25%, n = 225). Model performance was assessed using discrimination (area under the curve (AUC]) and calibration (Hosmer-Lemeshow test [HL]).

Results

The final model includes factors associated with increased risk of mortality, such as age (adjusted odds ratio, aOR 1.06 [95% confidence interval, CI 1.03, 1.10; p < 0.001]), National Institutes of Health Stroke Scale (NIHSS) score aOR 1.08 (95% CI 1.08, 1.13; p = 0.004), and diabetes aOR 2.29 (95% CI 1.20, 4.37; p = 0.012). The protective factors were antiplatelet within 48 h. aOR 0.40 (95% CI 0.19, 0.81; p = 0.01), dysphagia screening aOR 0.30 (95% CI 0.15, 0.61; p = 0.001), antiplatelets upon discharge aOR 0.17 (95% CI 0.08, 0.35; p < 0.001), lipid-lowering therapy aOR 0.37 (95% CI 0.17, 0.82; p = 0.01), stroke education aOR 0.02 (95% CI 0.01, 0.05; p < 0.001) and rehabilitation aOR 0.08 (95% CI 0.04, 0.16; p < 0.001). The model demonstrated excellent performance (discrimination [AUC = 0.94] and calibration [HL, X 2 p = 0.63]).

Conclusion

The study developed a validated prognostic model that excellently predicts mortality after a first-ever acute ischemic stroke with potential clinical utility in acute stroke care decision-making. The predictors could be valuable for creating risk calculators and aiding healthcare providers and patients in making well-informed clinical decisions during the stroke care process.

Reperfusion therapy and risk of post-stroke delirium

OBJECTIVES

Delirium is a common and serious post-stroke complication. Early reperfusion by ameliorating brain damage could potentially prevent delirium after ischemic stroke, but the impact of this therapy on delirium remains unclear. We aimed to explore the association between reperfusion therapy (RT) and post-stroke delirium.

METHODS

We retrospectively analyzed data from the PRospective Observational POLIsh Study on post-stroke delirium. Symptoms of delirium were examined during the first 7 days after admission and a diagnosis of delirium was made using Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria. We used logistic regression to examine the association between RT and delirium.

RESULTS

We included 301 acute stroke patients (median age: 77; median NIHSS: 14; 55.1% female). In the whole group of patients, RT was associated with a lower odds of delirium (34.2% vs 44.8%; adjusted OR: 0.56, 95% CI: 0.32-0.96, p = 0.035). There was a significant interaction between RT and pre-stroke cognitive status. As a result, RT was associated with a lower odds of delirium in patients without premorbid cognitive decline (28.8% vs 48.2%; adjusted OR: 0.34, 95% CI: 0.17-0.66, p = 0.002) and a higher odds of delirium in patients with pre-stroke cognitive decline (72.7% vs 41.0%; adjusted OR: 3.55, 95% CI: 1.03-12.20, p = 0.040).

DISCUSSION

The association between RT and delirium is modified by pre-stroke cognitive status. In patients without cognitive decline, RT is associated with a lower likelihood of delirium. Delirium should be considered as a relevant outcome in future controlled trials.

CLEC7A Knockdown Alleviates Ischemic Stroke by Inhibiting Pyroptosis and Microglia Activation

BACKGROUND

Ischemic stroke (IS) is the leading cause of mortality worldwide. Herein, we aimed to identify novel biomarkers and explore the role of C-type lectin domain family 7 member A (CLEC7A) in IS.

METHODS

Differentially expressed genes (DEGs) were screened using the GSE106680, GSE97537, and GSE61616 datasets, and hub genes were identified through construction of protein-protein interaction networks. An IS model was established by middle cerebral artery occlusion and reperfusion (MCAO/R). Neural function was assessed using triphenyl tetrazolium chloride, hematoxylin-eosin, and terminal deoxynucleotidyl transferase-mediated nick-end labeling. A cell counting kit was used to detect cell viability following oxygen-glucose deprivation/reperfusion (OGD/R). Inflammatory factors were detected using enzyme-linked immunosorbent assay. The mRNA and protein expression levels were detected using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively.

RESULTS

Fc fragment of Immunoglobulin G (IgG) receptor IIIa (FCGR3A), Fc fragment of Immunoglobulin E (IgE) receptor Ig (FCER1G), Complement component 5a receptor 1 (C5AR1), CLEC7A, Plasminogen activator, urokinase (PLAU), and C-C motif chemokine ligand 6 (CCL6) were identified as important hub genes, from which CLEC7A was selected as the primary subject of this study. The activation of microglia and pyroptosis were observed in MCAO/R model with increased levels of interleukin (IL)-1β, IL-18, tumor necrosis factor-α, and lactate dehydrogenase. CLEC7A knockdown was found to promote cell viability in BV2 cells and inhibiting pyroptosis in HT22 cells. CLEC7A knockdown in microglia also decreased infarct volume and neurological deficit scores, and alleviated injury and neuronal apoptosis in IS rats. CLEC7A knockdown inhibited pyroptosis and microglial activation in the MCAO/R model. A pyroptosis activator reversed the effect of CLEC7A knockdown on the viability of OGD/R-treated HT22 cells.

CONCLUSION

CLEC7A is a promising biomarker of IS. CLEC7A knockdown alleviates IS by inhibiting pyroptosis and microglial activation.

Intravenous thrombolysis therapy and dementia risk in acute ischemic stroke patients: A retrospective cohort study in Taiwan

Background

Intravenous thrombolysis (IVT) is the standard treatment for acute ischemic stroke (AIS) to improve functional outcomes. Furthermore, AIS is an important risk factor for dementia. Limited evidence has shown the long-term benefit of IVT on dementia in Western countries.

Objective

We aim to investigate the association between IVT and the risk of dementia in acute ischemic stroke patients in Asian population.

Methods

A retrospective cohort study using medical records from a medical center in Taiwan between 2017 and 2022 was conducted. We included acute ischemic stroke patients aged over 55 years old who had not previously been diagnosed with dementia. The primary outcome was incident dementia ascertained through dementia diagnosis in medical records. The inverse probability of treatment-weighted Cox proportional hazard models were used to estimate the association between IVT and incident dementia.

Results

A total of 1471 patients with AIS were included. 939 (63.8%) were male, and the mean age was 70.7± 9.6 years. Among them, 19.1% of patients (n = 281) received IVT. The mean follow-up time was 2.6± 1.7 years. Although not statistically significant, the IVT was associated with a decreased risk of dementia (HR: 0.88 [95%CI 0.54-1.41)]).

Conclusions

The IVT was associated with lower risk of dementia, although not statistically significant, in reducing the incidence of dementia in Asian patients with ischemic stroke. Studies with larger sample sizes will be needed in the future.

Vascular cognitive impairment and dementia: Mechanisms, treatment, and future directions

Worldwide, around 50 million people live with dementia, and this number is projected to triple by 2050. It has been estimated that 20% of all dementia cases have a predominant cerebrovascular pathology, while perhaps another 20% of vascular diseases contribute to a mixed dementia picture. Therefore, the vascular contribution to dementia affects 20 million people currently and will increase markedly in the next few decades, particularly in lower- and middle-income countries.In this review, we discuss the mechanisms of vascular cognitive impairment (VCI) and review management. VCI refers to the spectrum of cerebrovascular pathologies that contribute to any degree of cognitive impairment, ranging from subjective cognitive decline, to mild cognitive impairment, to dementia. While acute cognitive decline occurring soon after a stroke is the most recognized form of VCI, chronic cerebrovascular disease, in particular cerebral small-vessel disease, can cause insidious cognitive decline in the absence of stroke. Moreover, cerebrovascular disease not only commonly co-occurs with Alzheimer's disease (AD) and increases the probability that AD pathology will result in clinical dementia, but may also contribute etiologically to the development of AD pathologies.Despite its enormous health and economic impact, VCI has been a neglected research area, with few adequately powered trials of therapies, resulting in few proven treatments. Current management of VCI emphasizes prevention and treatment of stroke and vascular risk factors, with most evidence for intensive hypertension control. Reperfusion therapies in acute stroke may attenuate the risk of VCI. Associated behavioral symptoms such as apathy and poststroke emotionalism are common. We also highlight novel treatment strategies that will hopefully lead to new disease course-modifying therapies. Finally, we highlight the importance of including cognitive endpoints in large cardiovascular prevention trials and the need for an increased research focus and funding for this important area.

Vascular cognitive impairment and dementia: a narrative review

Vascular cognitive impairment (VCI) is the second most common cause of cognitive impairment after Alzheimer's disease. The VCI spectrum involves a decline in cognition attributable to vascular pathologies (e.g., large infarcts or hemorrhages, microinfarcts, microbleeds, lacunar infarcts, white matter hyperintensities, and perivascular space dilation). Pathophysiological mechanisms include direct tissue injury, small vessel disease, inflammaging (inflammation + aging), atrophy, and altered neurotransmission. VCI is diagnosed using distinct clinical and radiological criteria. It may lead to long-term disability and reduced quality of life. An essential factor for reducing cognitive impairment incidence is preventing stroke by managing traditional and non-traditional cerebrovascular risk factors. This article reviews the spectrum of VCI, epidemiology, risk factors, pathophysiology, diagnosis, available treatment, and preventive strategies.

Trifluoperazine regulates blood-brain barrier permeability via the MLCK/p-MLC pathway to promote ischemic stroke recovery

Blood-brain barrier (BBB) disruption following ischemic stroke (IS) can induce significant aftereffects. Elevated calmodulin (CaM) expression following stroke causes calcium overload-a key contributor to BBB collapse. Trifluoperazine (TFP), a CaM inhibitor, reduces CaM overexpression following IS. However, it remains unclear whether TFP participates in BBB repair after IS. We administered TFP to mice subjected to middle cerebral artery occlusion (MCAO) and bEnd.3 cells subjected to oxygen-glucose deprivation (OGD). TFP treatment in MCAO mice reduced cerebral CaM expression and infarct size and decreased BBB permeability. OGD-treated bEnd.3 cells showed significantly increased CaM protein levels and reduced tight junction (TJ) protein levels; these changes were reversed by TFP treatment. Our results found that TFP administration in mice inhibited actin contraction following cerebral ischemia-reperfusion by suppressing the MLCK/p-MLC pathway, thereby attenuating cell retraction, improving TJ protein integrity, and reducing BBB permeability. Consequently, this treatment may promote neurological function recovery after IS.

A Look at the Etiology of Alzheimer's Disease based on the Brain Ischemia Model

Alzheimer's disease (AD) is the frequent form of dementia in the world. Despite over 100 years of research into the causes of AD, including amyloid and tau protein, the research has stalled and has not led to any conclusions. Moreover, numerous projects aimed at finding a cure for AD have also failed to achieve a breakthrough. Thus, the failure of anti-amyloid and anti-tau protein therapy to treat AD significantly influenced the way we began to think about the etiology of the disease. This situation prompted a group of researchers to focus on ischemic brain episodes, which, like AD, mostly present alterations in the hippocampus. In this context, it has been proposed that cerebral ischemic incidents may play a major role in promoting amyloid and tau protein in neurodegeneration in AD. In this review, we summarized the experimental and clinical research conducted over several years on the role of ischemic brain episodes in the development of AD. Studies have shown changes typical of AD in the course of brain neurodegeneration post-ischemia, i.e., progressive brain and hippocampal atrophy, increased amyloid production, and modification of tau protein. In the post-ischemic brain, the diffuse and senile amyloid plaques and the development of neurofibrillary tangles characteristic of AD were revealed. The above data evidently showed that after brain ischemia, there are modifications in protein folding, leading to massive neuronal death and damage to the neuronal network, which triggers dementia with the AD phenotype.

Intravenous thrombolysis for acute ischemic stroke is associated with lower risk of post-stroke dementia: A nationwide cohort study

INTRODUCTION

Dementia after stroke is common and is a great concern for patients and their caregivers. The objective was to investigate if intravenous thrombolysis (IVT) for acute ischemic stroke (AIS) was associated with lower risk of dementia after stroke.

PATIENTS AND METHODS

When IVT was introduced in Denmark, not all eligible patients were treated due to restricted access. We conducted a nationwide register-based cohort study of all patients with AIS in Denmark from 2004 to 2011. IVT-treated patients were propensity score-matched with comparable non-treated patients. Cox proportional hazards regression was used to estimate the hazard ratio (HR) for all-cause and vascular dementia 2, 5, and 10 years after stroke.

RESULTS

Of the 5919 patients eligible for the study, 2305 IVT-treated patients were propensity score-matched with 2305 non-treated patients. Mean (SD) age was 66.6 (13.3) and 61.2% were male. Rate of all-cause dementia was lower for the IVT-treated 2 years (8.4/1000 person years (PY) vs 13.6/1000 PY, HR 0.63 (0.40-0.99)) and 5 years after stroke (7.3/1000 PY vs 11.4/1000 PY, HR 0.65 (0.46-0.91)). 10 years after stroke, the rates of all-cause dementia remained in favor of IVT (8.0/1000 PY vs 9.8/1000 PY, HR 0.83 (0.64-1.07)). IVT-treated had lower rates of vascular dementia 2 years (2.4/1000 PY vs 7.4/1000 PY, HR 0.33 (0.15-0.71)), 5 years (2.3/1000 PY vs 6.2/1000 PY, HR 0.38 (0.23-0.65)), and 10 years after stroke (3.0/1000 PY vs 5.4/1000 PY, HR 0.56 (0.38-0.81)).

CONCLUSION

IVT treatment was associated with lower long-term risk of both vascular and all-cause dementia after AIS.

Predicting 90-Day Prognosis in Ischemic Stroke Patients Post Thrombolysis Using Machine Learning

(1) Objective: This study aimed to construct a machine learning model for predicting the prognosis of ischemic stroke patients who underwent thrombolysis, assessed through the modified Rankin Scale (mRS) score 90 days after discharge. (2) Methods: Data were sourced from Qatar's stroke registry covering January 2014 to June 2022. A total of 723 patients with ischemic stroke who had received thrombolysis were included. Clinical variables were examined, encompassing demographics, stroke severity indices, comorbidities, laboratory results, admission vital signs, and hospital-acquired complications. The predictive capabilities of five distinct machine learning models were rigorously evaluated using a comprehensive set of metrics. The SHAP analysis was deployed to uncover the most influential predictors. (3) Results: The Support Vector Machine (SVM) model emerged as the standout performer, achieving an area under the curve (AUC) of 0.72. Key determinants of patient outcomes included stroke severity at admission; admission systolic and diastolic blood pressure; baseline comorbidities, notably hypertension (HTN) and coronary artery disease (CAD); stroke subtype, particularly strokes of undetermined origin (SUO); and hospital-acquired urinary tract infections (UTIs). (4) Conclusions: Machine learning can improve early prognosis prediction in ischemic stroke, especially after thrombolysis. The SVM model is a promising tool for empowering clinicians to create individualized treatment plans. Despite limitations, this study contributes to our knowledge and encourages future research to integrate more comprehensive data. Ultimately, it offers a pathway to improve personalized stroke care and enhance the quality of life for stroke survivors.

The Dual Role of Autophagy in Postischemic Brain Neurodegeneration of Alzheimer's Disease Proteinopathy

Autophagy is a self-defense and self-degrading intracellular system involved in the recycling and elimination of the payload of cytoplasmic redundant components, aggregated or misfolded proteins and intracellular pathogens to maintain cell homeostasis and physiological function. Autophagy is activated in response to metabolic stress or starvation to maintain homeostasis in cells by updating organelles and dysfunctional proteins. In neurodegenerative diseases, such as cerebral ischemia, autophagy is disturbed, e.g., as a result of the pathological accumulation of proteins associated with Alzheimer's disease and their structural changes. Postischemic brain neurodegeneration, such as Alzheimer's disease, is characterized by the accumulation of amyloid and tau protein. After cerebral ischemia, autophagy was found to be activated in neuronal, glial and vascular cells. Some studies have shown the protective properties of autophagy in postischemic brain, while other studies have shown completely opposite properties. Thus, autophagy is now presented as a double-edged sword with possible therapeutic potential in brain ischemia. The exact role and regulatory pathways of autophagy that are involved in cerebral ischemia have not been conclusively elucidated. This review aims to provide a comprehensive look at the advances in the study of autophagy behavior in neuronal, glial and vascular cells for ischemic brain injury. In addition, the importance of autophagy in neurodegeneration after cerebral ischemia has been highlighted. The review also presents the possibility of modulating the autophagy machinery through various compounds on the development of neurodegeneration after cerebral ischemia.

Apitherapy in Post-Ischemic Brain Neurodegeneration of Alzheimer's Disease Proteinopathy: Focus on Honey and Its Flavonoids and Phenolic Acids

Neurodegeneration of the brain after ischemia is a major cause of severe, long-term disability, dementia, and mortality, which is a global problem. These phenomena are attributed to excitotoxicity, changes in the blood-brain barrier, neuroinflammation, oxidative stress, vasoconstriction, cerebral amyloid angiopathy, amyloid plaques, neurofibrillary tangles, and ultimately neuronal death. In addition, genetic factors such as post-ischemic changes in genetic programming in the expression of amyloid protein precursor, β-secretase, presenilin-1 and -2, and tau protein play an important role in the irreversible progression of post-ischemic neurodegeneration. Since current treatment is aimed at preventing symptoms such as dementia and disability, the search for causative therapy that would be helpful in preventing and treating post-ischemic neurodegeneration of Alzheimer's disease proteinopathy is ongoing. Numerous studies have shown that the high contents of flavonoids and phenolic acids in honey have antioxidant, anti-inflammatory, anti-apoptotic, anti-amyloid, anti-tau protein, anticholinesterase, serotonergic, and AMPAK activities, influencing signal transmission and neuroprotective effects. Notably, in many preclinical studies, flavonoids and phenolic acids, the main components of honey, were also effective when administered after ischemia, suggesting their possible use in promoting recovery in stroke patients. This review provides new insight into honey's potential to prevent brain ischemia as well as to ameliorate damage in advanced post-ischemic brain neurodegeneration.

Cistanche tubulosa alleviates ischemic stroke-induced blood-brain barrier damage by modulating microglia-mediated neuroinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke (IS) has both high morbidity and mortality. Previous research conducted by our group demonstrated that the bioactive ingredients of the traditional medicinal and edible plant Cistanche tubulosa (Schenk) Wight (CT) have various pharmacological effects in treating nervous system diseases. However, the effect of CT on the blood-brain barrier (BBB) after IS are still unknown.

AIM OF THE STUDY

This study aimed to identify CT's curative effect on IS and explore its underlying mechanism.

MATERIALS AND METHODS

IS injury was established in a rat model of middle cerebral artery occlusion (MCAO). Gavage administration of CT at dosages of 50, 100, and 200 mg/kg/day was carried out for seven consecutive days. Network pharmacology was used for predicting the pathways and potential targets of CT against IS, and subsequent studies confirmed the relevant targets.

RESULTS

According to the results, both neurological dysfunction and BBB disruption were exacerbated in the MCAO group. Moreover, CT improved BBB integrity and neurological function and protected against cerebral ischemia injury. Network pharmacology revealed that IS might involve neuroinflammation mediated by microglia. Extensive follow-up studies verified that MCAO caused IS by stimulating the production of inflammatory factors and microglial infiltration. CT was found to influence neuroinflammation via microglial M1-M2 polarization.

CONCLUSION

These findings suggested that CT may regulate microglia-mediated neuroinflammation by reducing MCAO-induced IS. The results provide theoretical and experimental evidence for the efficacy of CT therapy and novel concepts for the prevention and treatment of cerebral ischemic injuries.

Transfer RNAs-derived small RNAs and their application potential in multiple diseases

The role of tRNAs is best known as adapter components of translational machinery. According to the central dogma of molecular biology, DNA is transcribed to RNA and in turn is translated into proteins, in which tRNA outstands by its role of the cellular courier. Recent studies have led to the revision of the canonical function of transfer RNAs (tRNAs), which indicates that tRNAs also serve as a source for short non-coding RNAs called tRNA-derived small RNAs (tsRNAs). tsRNAs play key roles in cellular processes by modulating complicated regulatory networks beyond translation and are widely involved in multiple diseases. Herein, the biogenesis and classification of tsRNAs were firstly clarified. tsRNAs are generated from pre-tRNAs or mature tRNAs and are classified into tRNA-derived fragments (tRFs) and tRNA halves (tiRNA). The tRFs include five types according to the incision loci: tRF-1, tRF-2, tRF-3, tRF-5 and i-tRF which contain 3′ tiRNA and 5′ tiRNA. The functions of tsRNAs and their regulation mechanisms involved in disease processes are systematically summarized as well. The mechanisms can elaborate on the specific regulation of tsRNAs. In conclusion, the current research suggests that tsRNAs are promising targets for modulating pathological processes, such as breast cancer, ischemic stroke, respiratory syncytial virus, osteoporosis and so on, and maintain vital clinical implications in diagnosis and therapeutics of various diseases.