Early epileptic seizures in ischaemic stroke treated by mechanical thrombectomy: influence of rt-PA

Role of blood-brain barrier dysfunction in the development of poststroke epilepsy

Stroke is a major contributor to mortality and morbidity worldwide and the most common cause of epilepsy in the elderly in high income nations. In recent years, it has become increasingly evident that both ischemic and hemorrhagic strokes induce dysfunction of the blood-brain barrier (BBB), and that this impairment can contribute to epileptogenesis. Nevertheless, studies directly comparing BBB dysfunction and poststroke epilepsy (PSE) are largely absent. Therefore, this review summarizes the role of BBB dysfunction in the development of PSE in animal models and clinical studies. There are multiple mechanisms whereby stroke induces BBB dysfunction, including increased transcytosis, tight junction dysfunction, spreading depolarizations, astrocyte and pericyte loss, reactive astrocytosis, angiogenesis, matrix metalloproteinase activation, neuroinflammation, adenosine triphosphate depletion, oxidative stress, and finally cell death. The degree to which these effects occur is dependent on the severity of the ischemia, whereby cell death is a more prominent mechanism of BBB disruption in regions of critical ischemia. BBB dysfunction can contribute to epileptogenesis by increasing the risk of hemorrhagic transformation, increasing stroke size and the amount of cerebral vasogenic edema, extravasation of excitatory compounds, and increasing neuroinflammation. Furthermore, albumin extravasation after BBB dysfunction contributes to epileptogenesis primarily via increased transforming growth factor β signaling. Finally, seizures themselves induce BBB dysfunction, thereby contributing to epileptogenesis in a cyclical manner. In repairing this BBB dysfunction, pericyte migration via platelet-derived growth factor β signaling is indispensable and required for reconstruction of the BBB, whereby astrocytes also play a role. Although animal stroke models have their limitations, they provide valuable insights into the development of potential therapeutics designed to restore the BBB after stroke, with the ultimate goal of improving outcomes and minimizing the occurrence of PSE. In pursuit of this goal, rapamycin, statins, losartan, semaglutide, and metformin show promise, whereby modulation of pericyte migration could also be beneficial.

Outcomes in Patients With Poststroke Seizures: A Systematic Review and Meta-Analysis

Importance

Published data about the impact of poststroke seizures (PSSs) on the outcomes of patients with stroke are inconsistent and have not been systematically evaluated, to the authors' knowledge.

Objective

To investigate outcomes in people with PSS compared with people without PSS.

Data Sources

MEDLINE, Embase, PsycInfo, Cochrane, LILACS, LIPECS, and Web of Science, with years searched from 1951 to January 30, 2023.

Study Selection

Observational studies that reported PSS outcomes.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was used for abstracting data, and the Joanna Briggs Institute tool was used for risk-of-bias assessment. Data were reported as odds ratio (OR) and standardized mean difference (SMD) with a 95% CI using a random-effects meta-analysis. Publication bias was assessed using funnel plots and the Egger test. Outlier and meta-regression analyses were performed to explore the source of heterogeneity. Data were analyzed from November 2022 to January 2023.

Main Outcomes and Measures

Measured outcomes were mortality, poor functional outcome (modified Rankin scale [mRS] score 3-6), disability (mean mRS score), recurrent stroke, and dementia at patient follow-up.

Results

The search yielded 71 eligible articles, including 20 110 patients with PSS and 1 166 085 patients without PSS. Of the participants with PSS, 1967 (9.8%) had early seizures, and 10 605 (52.7%) had late seizures. The risk of bias was high in 5 studies (7.0%), moderate in 35 (49.3%), and low in 31 (43.7%). PSSs were associated with mortality risk (OR, 2.1; 95% CI, 1.8-2.4), poor functional outcome (OR, 2.2; 95% CI, 1.8-2.8), greater disability (SMD, 0.6; 95% CI, 0.4-0.7), and increased dementia risk (OR, 3.1; 95% CI, 1.3-7.7) compared with patients without PSS. In subgroup analyses, early seizures but not late seizures were associated with mortality (OR, 2.4; 95% CI, 1.9-2.9 vs OR, 1.2; 95% CI, 0.8-2.0) and both ischemic and hemorrhagic stroke subtypes were associated with mortality (OR, 2.2; 95% CI, 1.8-2.7 vs OR, 1.4; 95% CI, 1.0-1.8). In addition, early and late seizures (OR, 2.4; 95% CI, 1.6-3.4 vs OR, 2.7; 95% CI, 1.8-4.1) and stroke subtypes were associated with poor outcomes (OR, 2.6; 95% CI, 1.9-3.7 vs OR, 1.9; 95% CI, 1.0-3.6).

Conclusions and Relevance

Results of this systematic review and meta-analysis suggest that PSSs were associated with significantly increased mortality and severe disability in patients with history of stroke. Unraveling these associations is a high clinical and research priority. Trials of interventions to prevent seizures may be warranted.

Early Epileptic Seizures after Ischemic Stroke: Their Association with Stroke Risk Factors and Stroke Characteristics

Background and Objectives: A growing number of stroke survivors face various stroke complications, including new-onset epileptic seizures (ESs). Post-stroke ESs are divided into early and late ESs based on the time of onset after stroke. Early ESs are associated with worse stroke outcomes, longer hospitalization and an increased risk of late ESs. A variety of risk factors for early ESs are being studied in order to prevent their occurrence. Therefore, we aim to determine the association of early ESs with ischemic stroke risk factors and characteristics. Materials and Methods: A total of 166 patients, treated for ischemic stroke in the Hospital of Lithuanian University of Health Sciences Kaunas Clinics, were enrolled in a prospective cohort study. Initially, data about stroke risk factors, localization, severity and treatment were collected, followed by an observation period of 14 days for early ESs. Results: Early ESs occurred in 11 (6.6%) participants. The probability of early ESs after ischemic stroke among males and females (LogRank = 1.281; p > 0.05), younger (≤65 y) and older (>65 y) participants (LogRank = 0.129; p > 0.05) was the same. The presence of ischemic stroke risk factors, such as atrial fibrillation (LogRank = 0.004; p > 0.05), diabetes mellitus (LogRank = 1.168; p > 0.05) and dyslipidemia (LogRank = 0.092; p > 0.05), did not increase the probability of early ESs. However, participants without a prior history of arterial hypertension (LogRank = 4.453; p < 0.05) were more likely to develop early ESs. Stroke localization (anterior versus posterior) (LogRank = 0.011; p > 0.05), stroke severity (LogRank = 0.395; p > 0.05) and type of treatment (specific versus non-specific) (LogRank = 1.783; p > 0.05) did not affect the probability of early ESs.

Risk of poststroke epilepsy after reperfusion therapies: A national cohort study

BACKGROUND AND PURPOSE

The risk of poststroke epilepsy (PSE) after endovascular treatment (EVT) is not well characterized. In this nationwide study, we assessed the risk of PSE after EVT and identified associated predictors.

METHODS

We included all individuals (n = 3319) treated with EVT (±intravenous thrombolysis [IVT]) between 2015 and 2019 in the Swedish National Quality Register for EVT. Two control groups were identified from the Swedish Stroke Register: the first treated with IVT alone (n = 3132) and the second with no treatment (n = 3184), both matched for age, sex, stroke severity, and time of stroke.

RESULTS

PSE developed in 7.9% (n = 410). The survival-adjusted 2-year risk was 6.5% (95% confidence interval [CI] = 5.28-7.70) after EVT, 10.0% (95% CI = 8.25-11.75) after IVT, and 12.3% after no revascularization (95% CI = 10.33-14.25). The hazard ratio (HR) of PSE after EVT was almost half compared to no treatment (HR = 0.51, 95% CI = 0.41-0.64). The risk of PSE after EVT was lower compared to no treatment in a multivariable Cox model that adjusted for age, sex, hemicraniectomy, and stroke severity (HR = 0.76, 95% CI = 0.60-0.96). Multivariable predictors of PSE after EVT were large infarction on computed tomography Day 1, high posttreatment National Institutes of Health Stroke Scale score, and need of assistance 3 months after stroke. IVT before EVT was associated with a lower risk of PSE (HR = 0.66, 95% CI = 0.46-0.94).

CONCLUSIONS

This nationwide study identified a reduced risk of PSE after EVT. Markers of severe infarction after EVT were associated with PSE, whereas IVT given before EVT was protective.

Incidence and association of seizures in stroke patients following endovascular treatment: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Post-stroke seizures (PSSs) are some of the most common complications of stroke and are associated with poor outcomes in patients. Endovascular treatment (EVT) is the standard of care for patients with acute ischaemic stroke related large-vessel occlusion. However, whether EVT increases the risk of PSSs remains controversial; the association between PSSs and EVT is poorly understood.

METHODS

PubMed, Embase and the Cochrane Library were searched for relevant studies published from 1995 to 6 December 2021. The overall incidence of PSSs in patients treated with EVT and the separate incidence for all included studies in each subgroup, stratified by the type of treatment or time of onset, were calculated. The pooled odds ratio and confidence interval were calculated to quantify the effects of EVT on PSS occurrence.

RESULTS

In all, 946 studies were screened and 16 articles were included, with a total sample size of 12,664 patients; 7836 patients received EVT, of whom 460 had PSS. The pooled incidence of PSS after EVT was 5.8%, which was similar to patients treated with mechanical thrombectomy (5.3%), intra-arterial thrombolysis (6.8%) or bridging therapy (5.4%). The cumulative incidence of post-stroke epilepsy (6.0%) was almost twice that of acute symptomatic seizures (3.6%). The pooled odds ratio for the relationship between EVT and PSS was 1.91 (95% confidence interval 0.98-3.73).

CONCLUSIONS

The cumulative incidence of stroke patients treated with EVT who developed seizures was 5.8%, and EVT was non-significantly associated with the occurrence of seizures after stroke.

Circular RNA circPHC3 Promotes Cell Death and Apoptosis in Human BMECs After Oxygen Glucose Deprivation via miR-455-5p/TRAF3 Axis in vitro

OBJECTIVE

Brain microvascular endothelial cells (BMECs) are involved in brain vascular dysfunction in ischemic stroke. Abnormal expression of circular RNAs regulate physiological and pathophysiological processes in the central nervous system. The aim of the present study was to investigate profile circRNAs in human BMECs after oxygen glucose deprivation (OGD), which was an in vitro model of ischemic stroke, and find promising biomarkers in ischemic stroke.

METHODS

RNA sequencing (RNA-seq) technology was conducted to analyze the differential expression of circRNAs between BMECs after OGD and non-OGD treated BMECs. RT-qPCR, cell proliferation, cell apoptosis and dual-luciferase assay, and so on, were used to investigate the functions and molecular mechanisms of hsa_circ_0001360 (named circPHC3 in this study) in ischemic stroke.

RESULTS

CircPHC3 was highly expressed in human BMECs after OGD. Knockdown of circPHC3 inhibited cell death and apoptosis in human BMECs treated with OGD. Mechanistically, circPHC3 acted as miR-455-5p sponge to activate TRAF3 to promote cell death and apoptosis in human BMECs after OGD.

CONCLUSION

In short, circPHC3 promotes cell death and apoptosis in ischemic stroke in vitro model, which might be a novel molecular target for acute cerebrovascular protection.