Mechanical thrombectomy in acute ischemic stroke

Differential Protective Effects of Edaravone in Cerebellar and Hippocampal Ischemic Injury Models

Ischemic stroke is a leading cause of mortality and disability, with cerebellar strokes posing severe complications such as herniation and brainstem compression. Edaravone, a radical scavenger known for reducing oxidative stress, has shown neuroprotective effects in cerebral strokes, but its impact on cerebellar strokes remains unclear. This study investigates Edaravone's protective properties in organotypic slice cultures of rat cerebellum and hippocampus, employing an oxygen-glucose deprivation (OGD) model to simulate ischemic stroke. The hippocampus served as comparative structure due to its high hypoxia sensitivity. Our results confirmed effective hypoxic induction with increases in HIF-1α and HIF-2α expression. Edaravone significantly reduced lactate dehydrogenase (LDH) levels, indicating diminished cellular damage, with cerebellar tissues showing greater vulnerability. Additionally, Edaravone reduced reactive oxygen species (ROS) in both tissues, though its efficacy may be limited by higher oxidative stress in cerebellar cultures. Seahorse XF analysis revealed that Edaravone preserved mitochondrial respiration and tissue integrity in cerebellar and hippocampal slice cultures. However, Edaravone was more effective in preserving mitochondrial respiration in hippocampal slices, suggesting that OGD-induced damage is more severe in cerebellar tissue. In conclusion, Edaravone demonstrates significant cell protective effects in both cerebellar and hippocampal tissues under OGD conditions, preserving tissue integrity and enhancing mitochondrial function in a tissue-dependent manner. These findings suggest Edaravone as a promising therapeutic candidate for cerebellar stroke. Further in vivo studies are required to assess its full clinical potential.

Unravelling neuroregenerative and neuroprotective roles of Wnt/β-catenin pathway in ischemic stroke: Insights into molecular mechanisms

Stroke is a serious condition often resulting in mortality or long-term disability, causing cognitive, memory, and motor impairments. A reduction in cerebral blood flow below critical levels defines the ischemic core and penumbra: the core undergoes irreversible damage, while the penumbra remains viable but functionally impaired. This functional impairment activates complex cell signaling pathways that determine cell survival or death, making the penumbra a key target for therapeutic interventions to prevent further damage. The Wnt/β-catenin (WβC) signaling pathway has emerged as a potential neuroprotective mechanism, promoting neurogenesis, angiogenesis, neuronal connectivity, and maintaining blood-brain barrier integrity after stroke. Activation of the WβC pathway also mitigates oxidative stress, inflammation, and apoptosis in ischemic regions, enhancing its neuroprotective effects. However, the overexpression of GSK3β and DKK1, or the presence of their agonists, can counteract these benefits. This review explores the therapeutic potential of WβC signaling, highlighting the effects of pharmacological modulation through antagonists, agonists, synthetic chemicals, natural products, stem cells, and macromolecules in preclinical models of ischemic stroke. While preclinical evidence supports the benefits of WβC activation, its role in human stroke requires further investigation. Additionally, the review discusses the potential adverse effects of prolonged WβC activation and suggests strategies to mitigate them. Overall, WβC signaling holds promise as a therapeutic target, offering insights into stroke pathophysiology and informing the development of novel treatment strategies.

Potential Mechanism and Perspectives of Mesenchymal Stem Cell Therapy for Ischemic Stroke: A Review

Mesenchymal stem cells (MSCs), as a stem cell type with multiple differentiation potentials and immune regulatory abilities, have shown broad prospects in the treatment of ischemic stroke in recent years. The main characteristics of MSCs include their self-renewal ability, differentiation potential for different types of cells, and the ability to secrete various bioactive factors such as cytokines, chemokines, and growth factors, which play a key role in tissue repair and regeneration. In the treatment of ischemic stroke, MSCs exert therapeutic effects through various mechanisms, including promoting vascular regeneration of damaged brain tissue, reducing inflammatory responses, and protecting neurons from damage caused by apoptosis. Research have shown that MSCs can promote the repair of ischemic areas by releasing neurotrophic factors and angiogenic factors, while inhibiting immune responses triggered by ischemia, thereby improving neurological function. With the in-depth study of its biological mechanism, MSCs have gradually shown good safety and effectiveness in clinical applications. Therefore, fully exploring and utilizing the potential of MSCs in the treatment of ischemic stroke may provide new ideas and solutions for future neural repair and regenerative medicine.

Cutting-edge advances in nano/biomedicine: A review on transforming thrombolytic therapy

Thrombotic blockages within blood vessels give rise to critical cardiovascular disorders, including ischemic stroke, venous thromboembolism, and myocardial infarction. The current approach to the therapy of thrombolysis involves administering Plasminogen Activators (PA), but it is hindered by fast drug elimination, narrow treatment window, and the potential for bleeding complications. Leveraging nanomedicine to encapsulate and deliver PA offers a solution by improving the efficacy of therapy, safeguarding the medicine from proteinase biodegradation, and reducing unwanted effects in in vivo trials. In this review, we delve into the underlying venous as well as arterial thrombus pathophysiology and provide an overview of clinically approved PA used to address acute thrombotic conditions. We explore the existing challenges and potential directions within recent pivotal research on a variety of targeted nanocarriers, such as lipid, polymeric, inorganic, and biological carriers, designed for precise delivery of PA to specific sites. We also discuss the promising role of microbubbles and ultrasound-assisted Sono thrombolysis, which have exhibited enhanced thrombolysis in clinical studies. Furthermore, our review delves into approaches for the strategic development of nano-based carriers tailored for targeting thrombolytic action and efficient encapsulation of PA, considering the intricate interaction in biology systems as well as nanomaterials. In conclusion, the field of nanomedicine offers a valuable method for the exact and effective therapy of severe thrombus conditions, presenting a pathway toward improved patient outcomes and reduced complications.

Optimizing Acute Ischemic Stroke Outcomes: The Role of Tenecteplase Before Mechanical Thrombectomy

PURPOSE

Acute ischemic stroke (AIS) is a life-threatening condition demanding prompt reperfusion to salvage brain tissue. Thrombolytic drugs, like tenecteplase (TNK), offer clot dissolution, but time constraints and contraindications limit their use. Mechanical thrombectomy (MT) revolutionized AIS treatment, especially for large vessel occlusions (LVO). Recent evidence suggests that administering TNK before MT improves recanalization and outcomes, challenging the dominance of alteplase.

METHODS

Relevant articles focusing on TNK before MT were retrieved from PubMed, Scopus, and Web of Science, looking for randomized controlled trials (RCT), clinical trials, and meta-analyses in humans until 2024.

FINDINGS

TNK, a genetically engineered thrombolytic, exhibits superior fibrin specificity and a longer half-life than alteplase. Clinical trials comparing TNK and alteplase before MT showcase enhanced recanalization, functional outcomes, and safety with TNK. Advanced neuroimaging aids patient selection, though its cost-effectiveness warrants consideration. Dosing studies favor a 0.25 mg/kg dose for efficacy and reduced complications. Clinical guidelines from various associations acknowledge TNK's potential as an alteplase alternative for AIS treatment, particularly for LVOs eligible for thrombectomy.

IMPLICATIONS

In conclusion, TNK emerges as a promising option for bridging therapy in AIS, displaying efficacy and safety benefits, especially when administered before MT. Its fibrin specificity, longer half-life, and potential for improved outcomes position TNK as a viable alternative to alteplase, potentially transforming the landscape of AIS treatment strategies. While limitations like small sample sizes and variations in protocols exist, future research should focus on large-scale RCT, subgroup analyses, and cost-effectiveness evaluations to further elucidate TNK's role in optimizing AIS management.

Mechanical Thrombectomy for Treatment of Acute Cerebral Infarction due to Distal Medium Vessel Occlusions: A Retrospective Cohort Study

BACKGROUND

Mechanical thrombectomy (MT) is standard of care for acute cerebral infarction (ACI) due to large vessel occlusions. However, its clinical efficacy in patients with ACI due to distal medium vessel occlusions (DMVOs) remains unclear. This study evaluates the efficacy and safety of MT in patients with ACI due to DMVOs.

METHODS

Totally, 306 patients with ACI at a very early stage were assigned into DMVOs-MT, M1-MT, and DMVOs-intravenous thrombolysis (IVT) groups. These groups were compared regarding baseline data, recanalization rate, location of vessel occlusions, number of thrombectomy, first-pass recanalization, mRS scores, NIHSS scores, 90-day mRS scores, incidence of adverse events, and mortality. Risk factors for poor prognosis of patients with DMVOs following MT were analyzed.

RESULTS

DMVOs-MT and M1-MT groups showed comparable first-pass recanalization rates, recanalization rates, and NIHSS score reduction ratios, with marked differences in location of vessel occlusions. Versus DMVOs-IVT, DMVOs-MT had increased differences between pre- and post-treatment NIHSS scores and between pre-treatment NIHSS scores and NIHSS scores at discharge and elevated NIHSS reduction ratios. The poor prognosis rate of DMVOs-MT group was insignificantly different from that of M1-MT group but lower than that of DMVOs-IVT group. Adverse events and mortality incidences were comparable among the three groups. Diabetes, first-pass recanalization, and pre-treatment NIHSS scores were independent risk factors for poor prognosis in DMVO patients after MT.

CONCLUSION

MT is as effective and safe in patients with DMVOs as in patients with M1 occlusions. In patients with DMVOs, MT has higher efficacy and safety than IVT.

Targeting PI3K/Akt in Cerebral Ischemia Reperfusion Injury Alleviation: From Signaling Networks to Targeted Therapy

Ischemia/reperfusion (I/R) injury is a pathological event that results in reperfusion due to low blood flow to an organ. Cerebral ischemia is a common cerebrovascular disease with high mortality, and reperfusion is the current standard intervention. However, reperfusion may further induce cellular damage and dysfunction known as cerebral ischemia/reperfusion injury (CIRI). Currently, strategies for the clinical management of CIRI are limited, necessitating the exploration of novel and efficacious treatment modalities for the benefit of patients. PI3K/Akt signaling pathway is an important cellular process associated with the disease. Stimulation of the PI3K/Akt pathway enhances I/R injury in multiple organs such as heart, brain, lung, and liver. It stands as a pivotal signaling pathway crucial for diminishing cerebral infarction size and safeguarding the functionality of brain tissue after CIRI. During CIRI, activation of the PI3K/Akt pathway exhibits a protective effect on CIRI. Furthermore, activation of the PI3K/Akt pathway has the potential to augment the activity of antioxidant enzymes, resulting in a decrease in reactive oxygen species (ROS) and the associated oxidative stress. Meanwhile, PI3K/Akt plays a neuroprotective role by inhibiting inflammatory responses and apoptosis. For example, PI3K/Akt interacts with NF-κB, Nrf2, and MAPK signaling pathways to mitigate CIRI. This article is aimed to explore the pivotal role and underlying mechanism of PI3K/Akt in ameliorating CIRI and investigate the influence of ischemic preconditioning and post-processing, as well as the impact of pertinent drugs or activators targeting the PI3K/Akt pathway on CIRI. The primary objective is to furnish compelling evidence supporting the activation of PI3K/Akt in the context of CIRI, elucidating its mechanistic intricacies. By doing so, the paper aims to underscore the critical contribution of PI3K/Akt in mitigating CIRI, providing a theoretical foundation for considering the PI3K/Akt pathway as a viable target for CIRI treatment.

Stem cell transplantation in cerebrovascular accidents: A global bibliometric analysis (2000-2023)

BACKGROUND

Cerebrovascular accident (CVA) is a major global contributor to death and disability. As part of its medical management, researchers have recognized the importance of promising neuroprotective strategies, where stem cell transplantation (SCT) is thought to confer advantages via trophic and neuroprotective effects.

AIM

To evaluate the current state of research on SCT in patients with CVA, assess key trends and highlight literature gaps.

METHODS

PubMed was screened for SCT in CVA-related articles in October 2023, for each country during the period between 2000 and 2023. Using the World Bank data, total population and gross domestic product were collected for comparison. VOSviewer_1.6.19 was used to create the VOS figure using the results of the same query. Graphs and tables were obtained using Microsoft Office Excel.

RESULTS

A total of 6923 studies were identified on SCT in CVA, making 0.03% of all published studies worldwide. Approximately, 68% were conducted in high-income countries, with a significant focus on mesenchymal stem cells. The journal "Stroke" featured the largest share of these articles, with mesenchymal SCT having the highest rate of inclusion, followed by hematopoietic SCT. Over time, there has been a noticeable shift from in vitro studies, which assess stem cell proliferation and neurogenesis, to in vivo studies aimed at evaluating efficacy and safety. Additionally, the number of reviews increased along this approach.

CONCLUSION

This bibliometric analysis provides a comprehensive guide for physicians and researchers in the field through an objective overview of research activity, and highlights both current trends and gaps. Having a potential therapeutic role in CVA, more research is needed in the future to focus on different aspects of SCT, aiming to reach a better treatment strategy and improve life quality in patients.

Evaluating high-flow oxygen therapy after mechanical thrombectomy under general anesthesia in acute ischemic stroke: A retrospective single-center study

BACKGROUND

The use of mechanical thrombectomy for acute intracranial vascular occlusion under general anesthesia with endotracheal intubation is well-established as a safe and effective method. However, the process of extubation post-surgery presents challenges for certain patients. This retrospective study assesses the safety and efficacy of combining mechanical ventilation with high-flow oxygen inhalation as an interim strategy, while also examining its impact on long-term clinical outcomes.

METHODS

This research enrolled 119 patients with acute intracranial large vessel occlusion who underwent mechanical thrombectomy under general anesthesia with tracheal intubation between January 2020 and November 2023. Participants were categorized into two groups: Group 1 (n=55), which received high-flow oxygen (HFO) post-extubation, and Group 2 (n=64), which was treated with routine oxygen supplementation (RO). The study compared reintubation and tracheotomy rates between these groups to determine safety and effectiveness. Additionally, it analyzed long-term clinical outcomes by comparing NIHSS and mRS scores before treatment and at 90-day follow-up.

RESULTS

The reintubation rate post-extubation was significantly lower in the HFO group (12.7 %, n=7) compared to the RO group (31.2 %, n=20, p=0.016). The incidence of tracheotomy within 7 days was also reduced in the HFO group compared to the RO group (7.3 %, n=4 vs 20.3 %, n=13, p=0.043). Moreover, a greater proportion of patients in the HFO group achieved mRS scores of 0-2 at 90 days post-stroke than those in the RO group (60 %, n=33 vs 40.6 %, n=26, p=0.035). The median NIHSS score at 90 days was more favorable in the HFO group than in the RO group (6, IQR [1-18] vs 8, IQR [1-20], p=0.005).

CONCLUSION

The study suggests that high-flow oxygen therapy after mechanical thrombectomy under general anesthesia with tracheal intubation may lessen the need for reintubation and tracheotomy, potentially leading to improved long-term prognosis.

High-frequency repetitive transcranial magnetic stimulation promotes neural stem cell proliferation after ischemic stroke

JOURNAL/nrgr/04.03/01300535-202408000-00031/figure1/v/2023-12-16T180322Z/r/image-tiff Proliferation of neural stem cells is crucial for promoting neuronal regeneration and repairing cerebral infarction damage. Transcranial magnetic stimulation (TMS) has recently emerged as a tool for inducing endogenous neural stem cell regeneration, but its underlying mechanisms remain unclear. In this study, we found that repetitive TMS effectively promotes the proliferation of oxygen-glucose deprived neural stem cells. Additionally, repetitive TMS reduced the volume of cerebral infarction in a rat model of ischemic stroke caused by middle cerebral artery occlusion, improved rat cognitive function, and promoted the proliferation of neural stem cells in the ischemic penumbra. RNA-sequencing found that repetitive TMS activated the Wnt signaling pathway in the ischemic penumbra of rats with cerebral ischemia. Furthermore, PCR analysis revealed that repetitive TMS promoted AKT phosphorylation, leading to an increase in mRNA levels of cell cycle-related proteins such as Cdk2 and Cdk4. This effect was also associated with activation of the glycogen synthase kinase 3β/β-catenin signaling pathway, which ultimately promotes the proliferation of neural stem cells. Subsequently, we validated the effect of repetitive TMS on AKT phosphorylation. We found that repetitive TMS promoted Ca2+ influx into neural stem cells by activating the P2 calcium channel/calmodulin pathway, thereby promoting AKT phosphorylation and activating the glycogen synthase kinase 3β/β-catenin pathway. These findings indicate that repetitive TMS can promote the proliferation of endogenous neural stem cells through a Ca2+ influx-dependent phosphorylated AKT/glycogen synthase kinase 3β/β-catenin signaling pathway. This study has produced pioneering results on the intrinsic mechanism of repetitive TMS to promote neural function recovery after ischemic stroke. These results provide a strong scientific foundation for the clinical application of repetitive TMS. Moreover, repetitive TMS treatment may not only be an efficient and potential approach to support neurogenesis for further therapeutic applications, but also provide an effective platform for the expansion of neural stem cells.

Fibrinogen binding to activated platelets and its biomimetic thrombus-targeted thrombolytic strategies

Thrombosis is associated with various fatal arteriovenous syndromes including ischemic stroke, myocardial infarction, and pulmonary embolism. However, current clinical thrombolytic treatment strategies still have many problems in targeting and safety to meet the thrombolytic therapy needs. Understanding the molecular mechanism that underlies thrombosis is critical in developing effective thrombolytic strategies. It is well known that platelets play a central role in thrombosis and the binding of fibrinogen to activated platelets is a common pathway in the process of clot formation. Based on this, a concept of biomimetic thrombus-targeted thrombolytic strategy inspired from fibrinogen binding to activated platelets in thrombosis was proposed, which could selectively bind to activated platelets at a thrombus site, thus enabling targeted delivery and local release of thrombolytic agents for effective thrombolysis. In this review, we first summarized the main characteristics of platelets and fibrinogen, and then introduced the classical molecular mechanisms of thrombosis, including platelet adhesion, platelet activation and platelet aggregation through the interactions of activated platelets with fibrinogen. In addition, we highlighted the recent advances in biomimetic thrombus-targeted thrombolytic strategies which inspired from fibrinogen binding to activated platelets in thrombosis. The possible future directions and perspectives in this emerging area are briefly discussed.

Real-time diagnosis of intracerebral hemorrhage by generating dual-energy CT from single-energy CT

Real-time diagnosis of intracerebral hemorrhage after thrombectomy is crucial for follow-up treatment. However, this is difficult to achieve with standard single-energy CT (SECT) due to similar CT values of blood and contrast agents under a single energy spectrum. In contrast, dual-energy CT (DECT) scanners employ two different energy spectra, which allows for real-time differentiation between hemorrhage and contrast extravasation based on energy-related attenuation characteristics. Unfortunately, DECT scanners are not as widely used as SECT scanners due to their high costs. To address this dilemma, in this paper, we generate pseudo DECT images from a SECT image for real-time diagnosis of hemorrhage. More specifically, we propose a SECT-to-DECT Transformer-based Generative Adversarial Network (SDTGAN), which is a 3D transformer-based multi-task learning framework equipped with a shared attention mechanism. In this way, SDTGAN can be guided to focus more on high-density areas (crucial for hemorrhage diagnosis) during the generation. Meanwhile, the introduced multi-task learning strategy and the shared attention mechanism also enable SDTGAN to model dependencies between interconnected generation tasks, improving generation performance while significantly reducing model parameters and computational complexity. In the experiments, we approximate real SECT images using mixed 120kV images from DECT data to address the issue of not being able to obtain the true paired DECT and SECT data. Extensive experiments demonstrate that SDTGAN can generate DECT images better than state-of-the-art methods. The code of our implementation is available at https://github.com/jiang-cw/SDTGAN.

Utility of Thrombectomy in Nonagenarians: A Scoping Review

BACKGROUND

Mechanical thrombectomy represents a mainstay of management for acute ischemic stroke in the setting of large vessel occlusion. However, there are no clinical practice guidelines defining the role of thrombectomy at the extremes of age. In this scoping review, we aimed to summarize the existing medical and neurosurgical literature pertaining to mechanical thrombectomy in nonagenarians. The PubMed database was queried using the following terms and relevant citations assessed: "thrombectomy nonagenarian," "thrombectomy age 90," "stroke nonagenarian," and "ischemic stroke thrombectomy." Common measurable outcomes, including mortality, modified Rankin scale (mRS) score, and thrombolysis in cerebral infarction (TICI) scale score, were utilized to compare results.

SUMMARY

Thrombectomy was shown to improve functional outcomes in all eight of the studies included in the analysis. Mortality was assessed in only two reported studies, and thrombectomy was shown to provide a mortality benefit in 1 study among patients for whom first-pass reperfusion was achieved. Other outcomes of reported interest included greater early neurologic recovery at discharge and improved functional outcomes at 90 days among nonagenarians who underwent thrombectomy as compared to those who received thrombolytic therapy alone. Nonagenarians with good functional status at baseline were the most likely to have favorable outcomes.

KEY MESSAGES

Mechanical thrombectomy improves outcomes among nonagenarians presenting with acute ischemic stroke due to large vessel occlusion. Further large-scale prospective studies are warranted to optimize patient selection and develop clinical practice guidelines specific to this important patient demographic.

Targeting NF-κB in Hepatic Ischemia-Reperfusion Alleviation: from Signaling Networks to Therapeutic Targeting

Hepatic ischemia-reperfusion injury (HIRI) is a major complication of liver trauma, resection, and transplantation that can lead to liver dysfunction and failure. Scholars have proposed a variety of liver protection methods aimed at reducing ischemia-reperfusion damage, but there is still a lack of effective treatment methods, which urgently needs to find new effective treatment methods for patients. Many studies have reported that signaling pathway plays a key role in HIRI pathological process and liver function recovery mechanism, among which nuclear transfer factor-κB (NF-κB) signaling pathway is one of the signal transduction closely related to disease. NF-κB pathway is closely related to HIRI pathologic process, and inhibition of this pathway can delay oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction. In addition, NF-κB can also interact with PI3K/Akt, MAPK, and Nrf2 signaling pathways to participate in HIRI regulation. Based on the role of NF-κB pathway in HIRI, it may be a potential target pathway for HIRI. This review emphasizes the role of inhibiting the NF-κB signaling pathway in oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction in HIRI, as well as the effects of related drugs or inhibitors targeting NF-κB on HIRI. The objective of this review is to elucidate the role and mechanism of NF-κB pathway in HIRI, emphasize the important role of NF-κB pathway in the prevention and treatment of HIRI, and provide a theoretical basis for the target NF-κB pathway as a therapy for HIRI.

Velvet antler polypeptide (VAP) protects against cerebral ischemic injury through NF-κB signaling pathway in vitro

OBJECTIVE

Velvet antler polypeptide (VAP) has been shown to play important roles in the immune and nervous systems. The purpose of this study was to investigate the protective effects of VAP on cerebral ischemic injury with the involvement of NF-κB signaling pathway in vitro.

MATERIALS AND METHODS

PC-12 cells stimulated by oxygen-glucose deprivation/reperfusion (OGD/R) was used to mimic cerebral ischemic injury in vitro. The levels of ROS, SOD, and intracellular concentrations of Ca2+ were measured by the relevant kits. Meanwhile, the expressions of inflammatory cytokines (IL-6, IL-1β, and TNF-α) were determined by ELISA kit assay. In addition, MTT, EdU, and flow cytometry assays were used to measure the cell proliferation and apoptosis. Besides which, the related proteins of NF-κB signaling pathway were measured by western blotting assay.

RESULTS

VAP alleviated cerebral ischemic injury by reducing OGD/R-induced oxidative stress, inflammation, and apoptosis in PC-12 cells in a time dependent manner. Mechanistically, VAP inhibited the levels of p-p65 and p-IkB-α in a time dependent manner, which was induced by OGD/R operation. Moreover, NF-κB agonist diprovocim overturned the suppression effects of VAP on OGD/R-induced oxidative stress, inflammation, and apoptosis in PC-12 cells.

CONCLUSIONS

The results demonstrate that VAP may alleviate cerebral ischemic injury by suppressing the activation of NF-κB signaling pathway.

External validation and comparison of MBE, EDEMA, and modified EDEMA scores for predicting malignant cerebral EDEMA in Chinese patients with large hemispheric infarction patients without revascularization

BACKGROUND

Malignant cerebral edema (MCE) is a severe condition characterized by rapid neurological deterioration and a potentially poor prognosis. Scoring systems including the malignant brain edema (MBE) score, Enhanced Detection of Edema in Malignant Anterior Circulation Stroke score (EDEMA), and modified EDEMA score, have been developed to predict MCE in patients with large hemispheric infarction (LHI). We aimed to externally validate and comparethe predictive efficacy of these scores in LHI patients within 48 h of onset and not undergoing reperfusion therapy.

METHODS

Demographic, clinical and radiological data were retrospectively collected from LHI patients within 48 h of onset and not receiving reperfusion therapy. Patients were divided into MCE and non-MCE group. The calibration, discrimination, and clinical practicability of the three scores were verified using Hosmer-Lemeshow goodness-of-fit test, receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA), respectively. Finally, continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were applied to determine the discrimination performance of the three scores.

RESULTS

A total of 314 patients were included in the study, with 122 cases being MCE patients. The Hosmer-Lemeshow goodness-of-fit test showed excellent fitting ability across the MBE (p = 0.36), EDEMA (p = 0.61), and modified EDEMA scores (p = 0.62) in our patients. The MBE, EDEMA, and modified EDEMA scores had the AUCs of 0.855 (95 % CI 0.818-0.898), 0.782 (95 % CI 0.727-0.837) and 0.878 (95 % CI 0.844-0.919) respectively. The MBE (NRI, 0.33; 95 % CI, 0.11-0.56, p = 0.003 and IDI, 0.11; 95 % CI, 0.03-0.18; p = 0.004) and modified EDEMA scores (NRI, 1.10; 95 % CI, 0.94-1.26; p < 0.001 and IDI, 0.17; 95 % CI, 0.13-0.20, p < 0.001) showed better performance than the EDEMA score. DCA demonstrated that the modified EDEMA score outperformed the other two scores, possessing heightened clinical usefulness.

CONCLUSIONS

The MBE, EDEMA, and modified EDEMA scores for predicting MCE are also applicable in non-revascularization LHI patients within 48 h of onset. Both the MBE and modified EDEMA scores demonstrated higher predictive validity as predictive tools for MCE in LHI patients than the EDEMA score. Furthermore, the modified EDEMA score could be a suitable prediction tool in Chinese patients for its excellent clinical utility.

Knockdown of FOXO4 protects against OGD/R‑induced cerebral microvascular endothelial cell injury and regulates the AMPK/Nrf2/HO‑1 pathway through transcriptional activation of CTRP6

Cerebral ischemia is a type of cerebrovascular disease with high disability and mortality rates. The expression of forkhead box protein O4 (FOXO4) in the brain is increased following traumatic brain injury. To the best of our knowledge, however, the role of FOXO4 as well as its mechanism in cerebral ischemia has not been reported so far. For the establishment of an in vitro cellular injury model, human brain microvascular endothelial HCMEC/D3 cells were induced by oxygen-glucose deprivation/reoxygenation (OGD/R). mRNA and protein expressions of FOXO4 and C1q/tumor necrosis factor-related protein 6 (CTRP6) in OGD/R-induced HCMEC/D3 cells were detected by reverse transcription-quantitative (RT-q)PCR and western blotting. The transfection efficacy of small interfering (si)- and overexpression (Ov)-FOXO4 and si-CTRP6 was assessed using RT-qPCR and western blotting. Cell Counting Kit-8 and TUNEL assay were used to assess viability and apoptosis of HCMEC/D3 cells induced by OGD/R, respectively. A FITC-Dextran assay kit was applied to determine endothelial permeability and immunofluorescence assay was used for the measurement of the tight junction protein zonula occludens-1. The levels of oxidative stress markers and inflammatory cytokines were assessed with corresponding assay kits. The binding sites of transcription factor, FOXO4 and CTRP6 promoter were predicted using HDOCK SERVER. Luciferase reporter assay was used to detect the activity of the CTRP6 promoter while chromatin immunoprecipitation assay was used to evaluate the binding ability of the FOXO4 and CTRP6 promoter. Western blotting was used for the detection of apoptosis- and AMPK/Nrf2/heme oxygenase-1 (HO-1) pathway-associated proteins, along with tight junction proteins. The expression of FOXO4 was increased in OGD/R-induced HCMEC/D3 cells. After interfering with FOXO4 in cells, the viability of the OGD/R-induced HCMEC/D3 cells was increased while apoptosis was decreased. Furthermore, FOXO4 interference improved cellular barrier dysfunction but inhibited oxidative stress and the inflammatory response in HCMEC/D3 cells induced by OGD/R. FOXO4 knockdown regulated CTRP6 transcription in HCMEC/D3 cells. Knockdown of FOXO4 regulated expression of CTRP6 and protected OGD/R-induced HCMEC/D3 cell injury via the AMPK/Nrf2/HO-1 pathway. The present study indicated that FOXO4 knockdown activated CTRP6 to protect against cerebral microvascular endothelial cell injury induced by OGD/R via the AMPK/Nrf2/HO-1 pathway.

Single-center outcomes of Onyx Frontier™ and Resolute Onyx™ drug-eluting balloon-mounted stents for rescue stenting for acute large vessel occlusion

BACKGROUND

In cases where mechanical thrombectomy (MT) fails, rescue stenting may be necessary to achieve reperfusion; however, the lack of standardized techniques or devices poses a challenge. This series aims to present our early experience with the Onyx Frontier™ and Resolute Onyx™ balloon-mounted drug-eluting stents for rescue stenting.

METHODS

A retrospective chart review was performed of all patients who underwent rescue stenting, in the setting of failed MT, using Onyx Frontier™ or Resolute Onyx™ stents at a single institution. Technical details, procedural complications, and patient outcomes were recorded for each case.

RESULTS

Twenty-two Onyx Frontier™ and Resolute Onyx™ stents were deployed in 18 patients undergoing rescue stenting. Stent locations included the middle cerebral artery (36.4%), internal carotid artery (18.2%), vertebral artery (22.7%), and basilar artery (22.7%). The average National Institutes of Health Stroke Scale score before MT was 13.8 (range 0-31). The median initial modified Rankin Scale (mRS) score was zero, while the median mRS score at follow-up was three. Successful reperfusion, as assessed by TICI scores, was achieved in 43.8% of patients for TICI 3, 43.8% for TICI 2C, and 12.5% for TICI 2B. Post-revascularization, 16.7% of patients experienced hemorrhage, of which one patient (5.6%) had symptomatic hemorrhage.

CONCLUSIONS

Onyx Frontier™ and Resolute Onyx™ stents are well suited for rescue stenting in cases of failed MT. These balloon-mounted drug-eluting stents exhibit excellent navigability, rendering them appropriate for rescue revascularization procedures. Our findings demonstrate that these stents confer a high degree of technical success.

Biomimetic nanoparticles in ischemic stroke therapy

Abstract

Ischemic stroke is one of the most severe neurological disorders with limited therapeutic strategies. The utilization of nanoparticle drug delivery systems is a burgeoning field and has been widely investigated. Among these, biomimetic drug delivery systems composed of biogenic membrane components and synthetic nanoparticles have been extensively highlighted in recent years. Biomimetic membrane camouflage presents an effective strategy to prolong circulation, reduce immunogenicity and enhance targeting. For one thing, biomimetic nanoparticles reserve the physical and chemical properties of intrinsic nanoparticle. For another, the biological functions of original source cells are completely inherited. Compared to conventional surface modification methods, this approach is more convenient and biocompatible. In this review, membrane-based nanoparticles derived from different donor cells were exemplified. The prospect of future biomimetic nanoparticles in ischemic stroke therapy was discussed.

Graphic abstract

Optimal allocation of physicians improves accessibility and workload disparities in stroke care

BACKGROUND

Inequalities in access to stroke care and the workload of physicians have been a challenge in recent times. This may be resolved by allocating physicians suitable for the expected demand. Therefore, this study analyzes whether reallocation using an optimization model reduces disparities in spatial access to healthcare and excessive workload.

METHODS

This study targeted neuroendovascular specialists and primary stroke centers in Japan and employed an optimization model for reallocating neuroendovascular specialists to reduce the disparity in spatial accessibility to stroke treatment and workload for neuroendovascular specialists in Japan. A two-step floating catchment area method and an inverted two-step floating catchment area method were used to estimate the spatial accessibility and workload of neuroendovascular specialists as a potential crowdedness index. Quadratic programming has been proposed for the reallocation of neuroendovascular specialists.

RESULTS

The reallocation of neuroendovascular specialists reduced the disparity in spatial accessibility and the potential crowdedness index. The standard deviation (SD) of the demand-weighted spatial accessibility index improved from 125.625 to 97.625. Simultaneously, the weighted median spatial accessibility index increased from 2.811 to 3.929. Additionally, the SD of the potential crowdedness index for estimating workload disparity decreased from 10,040.36 to 5934.275 after optimization. The sensitivity analysis also showed a similar trend of reducing disparities.

CONCLUSIONS

The reallocation of neuroendovascular specialists reduced regional disparities in spatial accessibility to healthcare, potential crowdedness index, and disparities between facilities. Our findings contribute to planning health policies to realize equity throughout the healthcare system.

Integrative Approaches in Acute Ischemic Stroke: From Symptom Recognition to Future Innovations

Among the high prevalence of cerebrovascular diseases nowadays, acute ischemic stroke stands out, representing a significant worldwide health issue with important socio-economic implications. Prompt diagnosis and intervention are important milestones for the management of this multifaceted pathology, making understanding the various stroke-onset symptoms crucial. A key role in acute ischemic stroke management is emphasizing the essential role of a multi-disciplinary team, therefore, increasing the efficiency of recognition and treatment. Neuroimaging and neuroradiology have evolved dramatically over the years, with multiple approaches that provide a higher understanding of the morphological aspects as well as timely recognition of cerebral artery occlusions for effective therapy planning. Regarding the treatment matter, the pharmacological approach, particularly fibrinolytic therapy, has its merits and challenges. Endovascular thrombectomy, a game-changer in stroke management, has witnessed significant advances, with technologies like stent retrievers and aspiration catheters playing pivotal roles. For select patients, combining pharmacological and endovascular strategies offers evidence-backed benefits. The aim of our comprehensive study on acute ischemic stroke is to efficiently compare the current therapies, recognize novel possibilities from the literature, and describe the state of the art in the interdisciplinary approach to acute ischemic stroke. As we aspire for holistic patient management, the emphasis is not just on medical intervention but also on physical therapy, mental health, and community engagement. The future holds promising innovations, with artificial intelligence poised to reshape stroke diagnostics and treatments. Bridging the gap between groundbreaking research and clinical practice remains a challenge, urging continuous collaboration and research.

Role of traditional Chinese medicine monomers in cerebral ischemia/reperfusion injury:a review of the mechanism

Ischemia/reperfusion (I/R) injury is a pathological process wherein reperfusion of an ischemic organ or tissue exacerbates the injury, posing a significant health threat and economic burden to patients and their families. I/R triggers a multitude of physiological and pathological events, such as inflammatory responses, oxidative stress, neuronal cell death, and disruption of the blood-brain barrier (BBB). Hence, the development of effective therapeutic strategies targeting the pathological processes resulting from I/R is crucial for the rehabilitation and long-term enhancement of the quality of life in patients with cerebral ischemia/reperfusion injury (CIRI). Traditional Chinese medicine (TCM) monomers refer to bioactive compounds extracted from Chinese herbal medicine, possessing anti-inflammatory and antioxidative effects, and the ability to modulate programmed cell death (PCD). TCM monomers have emerged as promising candidates for the treatment of CIRI and its subsequent complications. Preclinical studies have demonstrated that TCM monomers can enhance the recovery of neurological function following CIRI by mitigating oxidative stress, suppressing inflammatory responses, reducing neuronal cell death and functional impairment, as well as minimizing cerebral infarction volume. The neuroprotective effects of TCM monomers on CIRI have been extensively investigated, and a comprehensive understanding of their mechanisms can pave the way for novel approaches to I/R treatment. This review aims to update and summarize evidence of the protective effects of TCMs in CIRI, with a focus on their role in modulating oxidative stress, inflammation, PCD, glutamate excitotoxicity, Ca2+ overload, as well as promoting blood-brain barrier repairment and angiogenesis. The main objective is to underscore the significant contribution of TCM monomers in alleviating CIRI.

Rescue intracranial stenting for acute ischemic stroke after the failure of mechanical thrombectomy: A systematic review, meta-analysis, and trial sequential analysis

Background

Intracranial rescue stenting (RS) might be an option for acute ischemic stroke after the failure of mechanical thrombectomy (MT). However, the findings were not consistent in previous systematic reviews, and whether the conclusion was supported by sufficient statistical power is unknown.

Aim

To examine the effect of RS on acute ischemic stroke after the failure of MT with a systematic review, meta-analysis, and trial sequential analysis (TSA).

Methods

We searched Ovid Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to 15 June 2022, without any language restriction. Studies assessing the effect of RS for acute ischemia stroke after MT failure were included. Two reviewers independently screened the retrieved articles, extracted data, and evaluated the quality of the included studies through the New Ottawa Scale (NOS). The primary outcome was the recanalization rate after RS. Secondary outcomes included modified Rankin Scale (mRS) at 3 months after stroke, symptomatic intracranial hemorrhage (sICH), and mortality rate. We synthesized the data through a random-effects model and performed a TSA analysis.

Results

We included 15 studies (containing 1,595 participants) after screening 3,934 records. The pooled recanalization rate for rescue stenting was 82% (95% CI 77-87%). Compared with non-stenting, rescue stenting was associated with a higher proportion of patients with 0-2 mRS score (OR 3.96, 95% CI 2.69-5.84, p < 0.001) and a lower 90-day mortality rate (OR 0.46, 95% CI 0.32-0.65, p < 0.001), and stenting did not increase sICH rate (OR 0.63, 95% CI 0.39-1.04, p = 0.075). The TSA analysis showed that the meta-analysis of the mRS score had a sufficient sample size and statistical power.

Conclusions

Our study showed that rescue stenting was effective and safe for patients with acute ischemia stroke who also had a failed MT, and this result was confirmed in a TSA analysis.

The association between the severity and distribution of white matter lesions and hemorrhagic transformation after ischemic stroke: A systematic review and meta-analysis

Background and purpose

As a part of the natural course of ischemic stroke, hemorrhagic transformation (HT) is a serious complication after reperfusion treatment, which may affect the prognosis of patients with ischemic stroke. White matter lesions (WMLs) refer to focal lesions on neuroimaging and have been suggested to indicate a high risk of HT. This systematic review and meta-analysis aimed to summarize current evidence on the relation between WML and HT.

Methods

This systematic review was prepared with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched PubMed, Embase, Web of Science, and Cochrane Library databases for publications on WML and HT in patients with ischemic stroke. Odds ratios (ORs) and 95% confidence intervals (CIs) from eligible studies were combined to quantify the association between the severity of WML and the risk of HT. In addition, the descriptive analysis was adopted to evaluate the influence of different WML distributions on predicting HT.

Results

A total of 2,303 articles were identified after removing duplicates through database searching, and 41 studies were included in our final analysis. The meta-analysis showed that the presence of WML was associated with HT (OR = 1.62, 95%CI 1.08-2.43, p = 0.019) and symptomatic intracerebral hemorrhage (sICH) (OR = 1.64, 95%CI 1.17-2.30, p = 0.004), and moderate-to-severe WML indicated a high risk of HT (OR = 2.03, 95%CI 1.33-3.12, p = 0.001) and sICH (OR = 1.92, 95%CI 1.31-2.81, p < 0.001). The dose-response meta-analysis revealed risk effects of increasing the severity of WML on both HT and ICH. In addition, both periventricular WML (PWML) (five of seven articles) and deep WML (DWML) (five of six articles) were shown to be associated with HT.

Conclusions

White matter lesions are associated with overall HT and sICH in patients with ischemic stroke, and more severe WMLs indicate a high risk of HT and sICH. In addition, both PWML and DWMLs could be risk factors for HT.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: PROSPERO CRD42022313467.

Efficacy of intravenous thrombolysis combined with mechanical stent interventional thrombectomy on acute ischemic stroke

BACKGROUND

To investigate the efficacy and safety of intravenous thrombolysis combined with mechanical stent interventional thrombectomy in the treatment of acute ischemic stroke.

METHODS

A retrospective analysis was carried out for clinical data of 118 patients with acute ischemic stroke. The patients enrolled were divided into control group (recombinant tissue plasminogen activator (rt-PA) intravenous thrombolysis) and thrombectomy group (mechanical stent interventional thrombectomy based on rt-PA intravenous thrombolysis). The vascular recanalization rate and clinical efficacy after treatment were compared between the two groups. National Institutes of Health Stroke Scale (NIHSS) was used to identify the degree of neurological impairment in all patients before and after treatment, and Barthel Index was used to assess their activity of daily living. Moreover, the changes in the levels of T-lymphocyte subpopulation in peripheral blood and immuno-inflammatory factors before and after treatment were compared, and prognosis of patients and incidence of adverse reactions were recorded.

RESULTS

The response rate inthrombectomy group (93.2%) was significantly better than that in control group (76.3%). The NIHSS sore and modified Rankin scale (mRS) score after treatment were significantly lower than those before treatment, while the Barthel Index after treatment was distinctly higher than that before treatment. The NIHSS score and mRS score in thrombectomy group obviously declined compared with those in control group at 1 month after treatment. The Barthel Index in thrombectomy group was obviously higher than that in control group at 1 month and 2 months after treatment. Levels of cluster of differentiation 3 (CD3)+, CD3+CD4+, CD4+/CD8+ and natural killer (NK) cells in peripheral blood at 6 months after treatment evidently rose compared with those before treatment, while level of CD3+CD8+ evidently declined compared with that before treatment. In thrombectomy group, levels of CD3+, CD3+CD4+, CD4+/CD8+ and NK cells were markedly higher than those in control group, while the level of CD3+CD8+ was markedly lower than that in control group. Besides, in thrombectomy group, levels of serum osteopontin (OPN), malondialdehyde (MDA) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were evidently lower than those in control group at 1 month after treatment, while the level of serum superoxide dismutase (SOD) was evidently higher than that in control group. Compared with that in control group, the acute vascular reocclusion rate in thrombectomy group was significantly decreased at 3 months after treatment (10.2% vs. 22.0%).

CONCLUSIONS

Intravenous thrombolysis combined with mechanical stent interventional thrombectomy can effectively promote the vascular recanalization, improve the neurological function and activity of daily living of patients, reinforce the immunological function, inhibit the oxidative stress response and improve the prognosis of patients.

Inhibition of Cerebral Ischemia/Reperfusion Injury by MSCs-Derived Small Extracellular Vesicles in Rodent Models: A Systematic Review and Meta-Analysis

Small extracellular vesicles (sEVs) secreted by mesenchymal stem cells (MSCs) have shown great therapeutic potential in cerebral ischemia-reperfusion injury (CIRI). In this study, we firstly performed a systematic review to evaluate the efficacy of MSCs-derived sEV for experimental cerebral ischemia/reperfusion injury. 24 studies were identified by searching 8 databases from January 2012 to August 2022. The methodological quality was assessed by using the SYRCLE 's risk of bias tool for animal studies. All the data were analyzed using RevMan 5.3 software. As a result, the score of study quality ranged from 3 to 9 in a total of ten points. Meta-analyses showed that MSCs-derived sEVs could effectively alleviate neurological impairment scores, reduced the volume of cerebral infarction and brain water content, and attenuated neuronal apoptosis. Additionally, the possible mechanisms of MSCs-derived sEVs for attenuating neuronal apoptosis were inhibiting microglia-mediated neuroinflammation. Thus, MSCs-derived sEVs might be regarded as a novel insight for cerebral ischemic stroke. However, further mechanistic studies, therapeutic safety, and clinical trials are required. Systematic review registration. PROSPERO CRD42022312227.

Combining machine learning with radiomics features in predicting outcomes after mechanical thrombectomy in patients with acute ischemic stroke

BACKGROUND AND OBJECTIVE

Some patients with mechanical thrombectomy will have a poor prognosis. This study establishes a model for predicting the prognosis after mechanical thrombectomy in acute stroke based on diffusion-weighted imaging (DWI) omics characteristics.

METHODS

A total of 260 stroke patients receiving mechanical thrombectomy in our hospital were randomly divided into a training set (n = 182) and a test set (n = 78) in a 7:3 ratio. The regions of interest (ROI) of the imaging features of the DWI infarct area were extracted, and the minimum absolute contraction and selection operator regression model were used to screen the best radiomics features. A support vector machine classifier established the prediction model of the prognosis after mechanical thrombectomy of acute stroke based on the selected features. The prediction efficiency of the model was evaluated by the receiver operating characteristic (ROC) curve.

RESULTS

A total of 1936 radiomic features were extracted, and six features highly correlated with prognosis were screened after dimensionality reduction. Based on the DWI model, the ROC analysis showed that the area under the curve (AUC) for correct prediction in the training and test sets was 0.945 and 0.920, respectively.

CONCLUSION

The model based on the characteristics of radiomics and machine learning has high predictive efficiency for the prognosis of acute stroke after mechanical thrombectomy, which can be used to guide personalized clinical treatment.

Caffeine and Its Neuroprotective Role in Ischemic Events: A Mechanism Dependent on Adenosine Receptors

Ischemia is characterized by a transient, insufficient, or permanent interruption of blood flow to a tissue, which leads to an inadequate glucose and oxygen supply. The nervous tissue is highly active, and it closely depends on glucose and oxygen to satisfy its metabolic demand. Therefore, ischemic conditions promote cell death and lead to a secondary wave of cell damage that progressively spreads to the neighborhood areas, called penumbra. Brain ischemia is one of the main causes of deaths and summed with retinal ischemia comprises one of the principal reasons of disability. Although several studies have been performed to investigate the mechanisms of damage to find protective/preventive interventions, an effective treatment does not exist yet. Adenosine is a well-described neuromodulator in the central nervous system (CNS), and acts through four subtypes of G-protein-coupled receptors. Adenosine receptors, especially A1 and A2A receptors, are the main targets of caffeine in daily consumption doses. Accordingly, caffeine has been greatly studied in the context of CNS pathologies. In fact, adenosine system, as well as caffeine, is involved in neuroprotection effects in different pathological situations. Therefore, the present review focuses on the role of adenosine/caffeine in CNS, brain and retina, ischemic events.

Increased Number of Passes and Double Stent Retriever Technique Induces Cumulative Injury on Arterial Wall After Mechanical Thrombectomy in a Swine Model

The number of stentriever passes during endovascular thrombectomy impacts clinical outcomes in acute ischemic stroke. Previous studies suggest that the simultaneous double stent retriever technique (DSRT) could improve the efficacy and reduce the number of passes. We aim to analyze the degree of vessel wall injury according to the number of passes and technique (single vs. simultaneous devices). Histological changes were evaluated in renal arteries (RAs) of swine models after thrombectomy (1, 2, or 3 passes) with single stent (SSRT) and DSRT. Thrombectomy passes were performed in 12 RA: 3 samples from each artery were studied by optical microscopy to assess a vascular damage score. All thirty-six samples showed endothelial denudation and different degrees of damage in the deepest layers of the arterial wall; however, all arteries remained patent by the time of assessment. In all cases, the degree of vascular injury increased with the number of passes. Compared with a SSRT, DSRT showed a higher severity of histological damage corresponding to the damage caused by 1.4 SSRT passes. However, in distal arteries, vascular damage was relatively similar when comparing SSRT with multiple passes and DSRT with one pass. The degree of vessel injury increases with the number of passes. Even though histological damage per pass was 1.4 higher with DSRT than SSRT, short-term vessel patency was not compromised after up to 3 DSRT passes. Further studies are needed to characterize the risk-benefit ratio of the DSRT in routine clinical practice.

Outcomes of Mechanical Thrombectomy for Acute Ischemic Stroke When Multiple Passes Are Required and Associated Risk Factors

INTRODUCTION

This study aimed to evaluate the outcomes of mechanical thrombectomy for acute ischemic stroke when multiple passes are required and to identify the associated risk factors.

METHODS

Consecutive patients with acute ischemic stroke treated with mechanical thrombectomy at the Neurology Department of Ninth People's Hospital and the Neurosurgery Department of Xinhua Hospital of Shanghai Jiao Tong University School of Medicine from 2013 to 2018 were included. Patients were divided into 2 groups: those who received ≤2 passes and those who received >2 passes. Outcomes of the 2 groups were compared. Multivariate linear regression was used to determine factors associated with the need for >2 passes. All patient data were reviewed retrospectively.

RESULTS

A total of 122 patients were included, of whom 83 patients required ≤2 passes and 39 patients required >2 passes. After adjusting for sex, atrial fibrillation history, smoking history, and involvement of middle cerebral artery and internal cerebral artery, the National Institutes of Health Stroke Scale (NIHSS) score was associated with a 1.08-times greater risk of >2 passes (95% confidence interval [CI]: 1.01-1.17), and internal carotid artery with a 5.13-times greater risk of >2 passes (95% CI: 1.02-25.69). Having more than 2 passes was associated with significantly higher 7-day (25.6% vs. 6%), 90-day mortality rates (34.2% vs. 16%) and a significantly lower recanalization rate (66.7% vs. 89.2%).

CONCLUSION

Needing more than 2 passes during mechanical thrombectomy is associated with poorer outcomes. Higher preprocedural NIHSS scores and internal carotid artery thrombi are associated with more than 2 passes.

TCD hemodynamics findings in the subacute phase of anterior circulation stroke patients treated with mechanical thrombectomy

Despite mechanical thrombectomy, the prognosis for many patients with anterior circulation ischemic stroke (ACIS) remains poor. This retrospective study reports consecutive mechanical thrombectomy procedures for ACIS at our hospital over 4 years. Hemodynamics were explored using transcranial Doppler ultrasound. The functional outcome was assessed using the modified Rankin scale. A total of 121 eligible cases were included: 61 (50.4%) exhibited good outcomes (modified Rankin scale score ≤2) by day 90. The logistic regression analysis showed that ipsilateral middle cerebral artery (iMCA) systolic blood flow (SBF) (OR = 0.983, 95% CI: 0.969–0.997, P = 0.014), preoperative National Institutes of Health Stroke Scale (NIHSS)score (OR = 1.160, 95% CI: 1.067–1.261, P < 0.001), intracranial hemorrhage after therapy (OR = 19.514, 95% CI: 4.364–87.265, P < 0.001), and Alberta Stroke Program Early Computed Tomography Score (OR = 0.639, 95% CI: 0.416–0.981, P = 0.040) were independently associated with prognosis. The iMCA SBF and preoperative NIHSS score were significantly predictive of a good outcome in the receiver operating characteristic analysis. In conclusion, elevated iMCA SBF might be a prognostic indicator of a good 90-day outcome following endovascular treatment in ACIS patients treated with mechanical thrombectomy, but large prospective studies are mandatory to validate the findings of our study.

Gut-Brain Axis as a Pathological and Therapeutic Target for Neurodegenerative Disorders

Human lifestyle and dietary behaviors contribute to disease onset and progression. Neurodegenerative diseases (NDDs), considered multifactorial disorders, have been associated with changes in the gut microbiome. NDDs display pathologies that alter brain functions with a tendency to worsen over time. NDDs are a worldwide health problem; in the US alone, 12 million Americans will suffer from NDDs by 2030. While etiology may vary, the gut microbiome serves as a key element underlying NDD development and prognosis. In particular, an inflammation-associated microbiome plagues NDDs. Conversely, sequestration of this inflammatory microbiome by a correction in the dysbiotic state of the gut may render therapeutic effects on NDDs. To this end, treatment with short-chain fatty acid-producing bacteria, the main metabolites responsible for maintaining gut homeostasis, ameliorates the inflammatory microbiome. This intimate pathological link between the gut and NDDs suggests that the gut-brain axis (GBA) acts as an underexplored area for developing therapies for NDDs. Traditionally, the classification of NDDs depends on their clinical presentation, mostly manifesting as extrapyramidal and pyramidal movement disorders, with neuropathological evaluation at autopsy as the gold standard for diagnosis. In this review, we highlight the evolving notion that GBA stands as an equally sensitive pathological marker of NDDs, particularly in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and chronic stroke. Additionally, GBA represents a potent therapeutic target for treating NDDs.

Enhancement of intercellular interaction between iPSC-derived neural progenitor cells and activated endothelial cells using cell surface modification with functional oligopeptides

Cell-based therapy has been used to treat stroke related disorders, which have no treatment options available 4.5 hours after onset. Although the administration of tissue plasminogen activator and mechanical thrombectomy are potent treatments, their clinical implementation is limited within the available time. Here, we aimed to use induced pluripotent stem cell-derived neural progenitor cells (NPCs) for stroke treatment with higher delivery efficiency in stroke areas, which will improve the therapeutic effect. E-selectin binding oligopeptide (Esbp) was conjugated with poly(ethylene glycol)-conjugated-lipid (Esbp-PEG-lipid) with different molecular weights of PEG (5 and 40 kDa) for cell surface modification. Then, we optimized the cell surface modification of NPCs by studying cell-binding ability onto the model surfaces of stroke areas, such as recombinant E-selectin-immobilized surfaces and TNF-α activated endothelium. As a result, the cell surface modification of NPCs with Esbp-PEG-lipid was found to induce specific intercellular interactions with the activated endothelium through the binding of Esbp with E-selectin. Additionally, the shorter PEG spacer was suitable for intercellular interactions. Thus, our technique shows potential for use in cell therapy with enhanced cell accumulation in infarct areas.

Astrocytic glycogen mobilization participates in salvianolic acid B-mediated neuroprotection against reperfusion injury after ischemic stroke

Astrocytic glycogen serves as an important glucose reserve, and its degradation provides extra support for neighboring neurons during energy deficiency. Salvianolic acid B (SAB) exerts a neuroprotective effect on reperfusion insult after cerebrovascular occlusion, but the effect of SAB on astrocytic glycogen and its relationship with neuroprotection are not completely understood. Here, we knocked down astrocyte-specific glycogen phosphorylase (GP, the rate-limiting enzyme in glycogenolysis) in vitro and in vivo and investigated the changes in key enzymes in glycogen metabolism by performing immunoblotting in vitro and immunofluorescence in vivo. Neurobehavioral and morphological assessments were conducted to uncover the outcomes during brain reperfusion. SAB accelerated astrocytic glycogenolysis by upregulating GP activity but not GP expression after reperfusion. Suppression of astrocytic glycogenolysis weakened SAB-mediated neuroprotection against the reperfusion insult. In addition, activation of glycogenolysis by SAB contributed to the survival of astrocytes and surrounding neurons by increasing antioxidant levels in astrocytes. Our data reveal that astrocytic GP represents an important metabolic target in SAB-induced protection against brain damage after cerebrovascular recanalization.

Current status of ischemic stroke treatment: From thrombolysis to potential regenerative medicine

Ischemic stroke is a major cause of death and disability worldwide and is expected to increase in the future with the aging population. Currently, there are no clinically available treatments for damage sustained during an ischemic stroke, but much research is being conducted in this area. In this review, we will introduce current ischemic stroke treatments along with their limitations, as well as research on potential short and long-term future treatments. There are advantages and disadvantages in these potential treatments, but our understanding of these methods and their effectiveness in clinical trials are improving. We are confident that some future treatments introduced in this review will become commonly used in clinical settings in the future.

Use of Traditional Chinese Medicine and Its Impact on Medical Cost among Urban Ischemic Stroke Inpatients in China: A National Cross-Sectional Study

BACKGROUND

Traditional Chinese medicine (TCM) has long been widely adopted by the Chinese people and has been covered by China's basic medical insurance schemes to treat ischemic stroke. Previous research has mainly highlighted the therapy effect of TCM on ischemic stroke patients. Some studies have demonstrated that employing TCM can reduce the medical burden on other diseases. But no research has explored whether using TCM could reduce inpatient medical cost for ischemic stroke in mainland China. The purpose of this study is to investigate the impact of the use of TCM on the total inpatient cost of ischemic stroke and to explore whether TCM has played the role of being complementary to, or an alternative for, conventional medicine to treat ischemic stroke.

METHODS

We conducted a national cross-sectional analysis based on a 5% random sample from claims data of China Urban Employee Basic Medical Insurance (UEBMI) and Urban Resident Basic Medical Insurance (URBMI) schemes in 2015. Mann-Whitney test was used to compare unadjusted total inpatient cost, conventional medication cost, and nonpharmacy cost estimates. Ordinary least square regression analysis was performed to compare demographics-adjusted total inpatient cost and to examine the association between TCM cost and conventional medication cost.

RESULTS

A total of 47321 urban inpatients diagnosed with ischemic stroke were identified in our study, with 92.6% (43843) of the patients using TCM in their inpatient treatment. Total inpatient cost for TCM users was significantly higher than TCM nonusers (USD 1217 versus USD 1036, P < 0.001). Conventional medication cost was significantly lower for TCM users (USD 335 versus USD 436, P < 0.001). The average cost of TCM per patient among TCM users was USD 289. Among TCM users, conventional medication costs were found to be positively associated with TCM cost after adjusting for confounding factors (Coef. = 0.144, P < 0.001).

CONCLUSION

Although the use of TCM reduced the cost of conventional medicine compared with TCM nonusers, TCM imposed an extra financial component on the total inpatient cost on TCM users. Our study suggests that TCM mainly played a complementary role to conventional medicine in ischemic stroke treatment in mainland China.

Delayed massive cerebral infarction after perioperative period of anterior cervical discectomy and fusion: A case report

BACKGROUND

Cerebral infarction is an extremely rare postoperative complication of anterior cervical discectomy and fusion (ACDF), particularly in the delayed setting. We present a case who had a sudden stroke on day 18 after surgery. By sharing our experience with this case, we hope to provide new information about stroke after anterior cervical surgery.

CASE SUMMARY

We present the case of a 61-year-old man with more than 20 years of hypertension and 14 years of coronary heart disease who had suffered a stroke 11 years ago. The patient was admitted for a multiple ACDF due to symptoms of cervical spondylotic myelopathy and had a sudden stroke on day 18 after surgery. Imaging findings showed a large-area infarct of his left cerebral hemisphere and thrombosis in his left common carotid artery. With the consent of his family, the thrombus was removed and a vascular stent was implanted through an interventional operation. Forty days later, the patient was transferred to a rehabilitation hospital for further treatment. He had normal consciousness but slurred speech at the 1-year follow-up evaluation. The motor and sensory functions of his hemiplegic limbs partially recovered.

CONCLUSION

This case illustrated that a postoperative stroke related to anterior cervical surgery may be attributed to prolonged carotid retraction and might have a long silent period. Preventive measures include careful preoperative and postoperative examination for high-risk patients as well as gentle and intermittent retraction of carotid artery sheath during operation.

Prognostic value of elevated high-sensitivity cardiac troponin T in acute ischemic stroke patients treated with endovascular thrombectomy in late time windows

OBJECTIVE

To evaluate the prognostic significance of high-sensitivity cardiac troponin T (hs-cTnT) elevation in acute ischemic stroke (AIS) patients with large vessel occlusion (LVO) in the anterior circulation treated with endovascular thrombectomy (ET) in late time windows and identify the factors associated with hs-cTnT elevation.

METHODS

A total of 152 AIS patients treated with ET in late time windows between January 2018 and August 2020 were included in this study. Patients were stratified into either normal or elevated hs-cTnT groups according to a cutoff value of 14 ng/L on admission. Baseline demographic features, comorbidities, and imaging data were compared between the elevated hs-cTnT group (＞14 ng/L) and the normal hs-cTnT group (≤14 ng/L). After accounting for these clinical characteristics, the association between hs-cTnT elevation and clinical outcomes was evaluated.

RESULTS

69(45.4%) patients had elevated hs-cTnT levels (>14 ng/L) on admission. The multivariable logistic regression analysis demonstrated that hs-cTnT elevation was independently associated with 3-month all-cause mortality (P = 0.014, OR 3.907, 95% CI 1.313-11.625) and 3-month composite unfavorable outcome (mRS 3-6) (P = 0.001, OR 5.099, 95% CI 1.873-13.888). Old age (P = 0.002, OR 1.053, 95% CI 1.020-1.088), admission NIHSS score (P = 0.015, OR 1.057, 95% CI 1.011-1.106), congestive heart failure (P = 0.016, OR 4.341, 95% CI 1.322-14.257) and coronary artery disease (P = 0.020, OR 2.914, 95% CI 1.183-7.180) were independently associated with hs-cTnT elevation.

CONCLUSION

In AIS patients treated with ET in late time windows, elevated hs-cTnT is independently associated with an increased risk of 3-month poor outcomes. Old age, high admission NIHSS score, coronary artery disease, and congestive heart failure are independent predictors of hs-cTnT elevation.

Combination of Stem Cells and Rehabilitation Therapies for Ischemic Stroke

Stem cell transplantation with rehabilitation therapy presents an effective stroke treatment. Here, we discuss current breakthroughs in stem cell research along with rehabilitation strategies that may have a synergistic outcome when combined together after stroke. Indeed, stem cell transplantation offers a promising new approach and may add to current rehabilitation therapies. By reviewing the pathophysiology of stroke and the mechanisms by which stem cells and rehabilitation attenuate this inflammatory process, we hypothesize that a combined therapy will provide better functional outcomes for patients. Using current preclinical data, we explore the prominent types of stem cells, the existing theories for stem cell repair, rehabilitation treatments inside the brain, rehabilitation modalities outside the brain, and evidence pertaining to the benefits of combined therapy. In this review article, we assess the advantages and disadvantages of using stem cell transplantation with rehabilitation to mitigate the devastating effects of stroke.

Middle Cerebral Artery Thrombectomy: Clinical Findings and Technical Pearls: 2-Dimensional Operative Video

Mechanical thrombectomy as a treatment for large vessel occlusion to achieve rapid revascularization is supported in the literature.1-3 The presenting symptoms will localize to functions of the ischemic area. The middle cerebral artery (MCA) supplies areas of the frontal, temporal, and parietal cortices, as well as the basal ganglia. Occlusion of the MCA will present with contralateral hemiplegia, sensory loss, and, if the dominant hemisphere is involved, language deficits. We present a right-hand-dominant 79-yr-old female with right MCA syndrome-her last known well time was 1.5 h prior to presentation. Her NIH (National Institutes of Health) Stroke Scale was 16, most notable for left hemiplegia. Although the patient presented early in the clinical time course, as part of our institution protocol, a computed tomography (CT) head, CT perfusion, and CT angiogram (CTA) were performed. CT head did not demonstrate acute hemorrhage, so she received intravenous tissue plasminogen activator. CTA demonstrated a right MCA occlusion and CT perfusion suggested a large area of salvageable tissue, so she was taken to the angiography suite for mechanical thrombectomy. Angiography of the right internal carotid artery (ICA) showed MCA occlusion (insular segment). A thrombectomy device was deployed over the area of occlusion and allowed to engage for 5 min. An aspiration catheter was advanced over the stentriever up against the clot. The stentriever device was withdrawn under continuous aspiration and follow-up angiography showed complete reperfusion. The patient demonstrated improvement and was eventually discharged to an inpatient rehabilitation center. Patient provided consent for photography per university protocol. Institutional review board (IRB) approval was not needed for the single-patient data included in this report.

Arctium lappa L. roots ameliorates cerebral ischemia through inhibiting neuronal apoptosis and suppressing AMPK/mTOR-mediated autophagy

BACKGROUND

Arctium lappa L. roots are very popular cultivated vegetables, which possesses various pharmacological activities. Our previous studies have demonstrated that Arctium lappa L. roots exerted protective effects against H₂O₂, glutamate and N-methyl-D-aspartic acid (NMDA)-induced neuronal injury in vitro. However, whether Arctium lappa L. roots could prevent against cerebral ischemia and the underlying mechanism remain unclear.

PURPOSE

The objective of the present study was to investigate the neuroprotective effects of ethyl acetate extract of Arctium lappa L. roots (EAL) and the active ingredient 4,5-O-dicaffeoyl-1-O-[4-malic acid methyl ester]-quinic acid (DCMQA) in EAL against cerebral ischemia and explore the underlying mechanism.

STUDY DESIGN

The neuroprotective effects of EAL and DCMQA were investigated in rats with permanent middle cerebral artery occlusion (MCAO) and in oxygen glucose deprivation/reoxygenation (OGD/R)-stimulated SH-SY5Y cells, respectively.

METHODS

The infarct volume, brain edema and neurological deficits were measured following MCAO. TUNEL and Nissl staining were performed to detect neuronal loss and apoptosis of neurons in rat brains. Cell survival was measured by MTT and LDH assay. In addition, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) levels were determined by DCFH-DA and JC-1 fluorescent probe, respectively. Hoechst 33342 staining and Annexin V-FITC/PI double staining were performed to evaluate neuronal apoptosis. The expression levels of proteins were evaluated by western blot.

RESULTS

EAL reduced brain infarct volume, ameliorated brain edema and improved neurological deficits in MCAO rats. In addition, EAL inhibited oxidative stress and inflammatory responses following MCAO. Besides, active compound DCMQA alleviated cytotoxicity as well as inhibited over-production of intracellular ROS and loss of MMP induced by OGD/R in SH-SY5Y cells. Moreover, EAL and DCMQA inhibited apoptosis by decreasing the expressions of pro-apoptotic proteins including bax, cytochrome c and cleaved caspase-3 while promoting the bcl-2 expression in MCAO rats and OGD/R-stimulated neurons, respectively. In addition, DCMQA suppressed the production of autophagosomes and down-regulated expression of Beclin 1 and LC3. Furthermore, inhibiting AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway contributed to DCMQA-mediated suppression of autophagy induced by OGD/R.

CONCLUSION

Our findings demonstrate that Arctium lappa L. roots protect against cerebral ischemia through inhibiting apoptosis and AMPK/mTOR-mediated autophagy in vitro and in vivo, providing a theoretical basis for the development of CQAs in Arctium lappa L. roots as neuroprotective drugs for the prevention and treatment of ischemic stroke.

Early diagnosis and prediction of intracranial hemorrhage using dual-energy computed tomography after mechanical thrombectomy in patients with acute ischemic stroke

PURPOSE

This study assesses the clinical value of dual-energy computed tomography (DECT) in the early diagnosis of intracranial hemorrhage and evaluates the risk of hemorrhagic transformation in patients with acute ischemic stroke (AIS) after mechanical thrombectomy.

METHODS

Patients with AIS who have undergone thrombectomy with Solitaire stent and DECT within one hour after surgery were prospectively enrolled. Linear mixed energy images, virtual non-contrast (VNC) image, and iodine overlay map (IOM) were obtained. Routine CT scan was performed 24 h postoperatively. The sensitivity, specificity, positive and negative predictive values, and accuracy of DECT in the early diagnosis of intracranial hemorrhage was evaluated. The iodine concentration of intracranial lesions was measured by IOM with the follow-up results taken as reference. Receiver operating characteristic (ROC) analysis was performed to obtain the threshold of hemorrhagic transformation and increased bleeding.

RESULTS

Among the 44 patients enrolled in this study, 25 (56.8 %) were diagnosed with simple extravasation of iodinated contrast agent, and 19 (43.2 %) showed intracranial hemorrhage in DECT. Compared with the follow-up CT 24 h after surgery, early diagnosis of postoperative intracranial hemorrhage using DECT demonstrated a sensitivity of 90.5 %, specificity of 100 %, positive predictive rate of 100 %, negative predictive rate of 92.0 %, and accuracy of 95.5 %. Among the 86 intracranial lesions that underwent iodine concentration measurement, 19 were diagnosed with hemorrhagic transformation or increased bleeding, and 67 were diagnosed without the aforementioned conditions. The sensitivity and specificity for differentiating the two groups were 73.7 % and 92.5 %, respectively, with a cut-off value of 2.7 mg/mL.

CONCLUSION

DECT is clinically valuable in early diagnosis and prediction of intracranial hemorrhage after mechanical thrombectomy in AIS patients.

HDAC9 Silencing Exerts Neuroprotection Against Ischemic Brain Injury via miR-20a-Dependent Downregulation of NeuroD1

Cerebral stroke is an acute cerebrovascular disease that is a leading cause of death and disability worldwide. Stroke includes ischemic stroke and hemorrhagic strokes, of which the incidence of ischemic stroke accounts for 60–70% of the total number of strokes. Existing preclinical evidence suggests that inhibitors of histone deacetylases (HDACs) are a promising therapeutic intervention for stroke. In this study, the purpose was to investigate the possible effect of HDAC9 on ischemic brain injury, with the underlying mechanism related to microRNA-20a (miR-20a)/neurogenic differentiation 1 (NeuroD1) explored. The expression of HDAC9 was first detected in the constructed middle cerebral artery occlusion (MCAO)-provoked mouse model and oxygen-glucose deprivation (OGD)-induced cell model. Next, primary neuronal apoptosis, expression of apoptosis-related factors (Bax, cleaved caspase3 and bcl-2), LDH leakage rate, as well as the release of inflammatory factors (TNF-α, IL-1β, and IL-6) were evaluated by assays of TUNEL, Western blot, and ELISA. The relationships among HDAC9, miR-20a, and NeuroD1 were validated by in silico analysis and ChIP assay. HDAC9 was highly-expressed in MCAO mice and OGD-stimulated cells. Silencing of HDAC9 inhibited neuronal apoptosis and inflammatory factor release in vitro. HDAC9 downregulated miR-20a by enriching in its promoter region, while silencing of HDCA9 promoted miR-20a expression. miR-20a targeted Neurod1 and down-regulated its expression. Silencing of HDAC9 diminished OGD-induced neuronal apoptosis and inflammatory factor release in vitro as well as ischemic brain injury in vivo by regulating the miR-20a/NeuroD1 signaling. Overall, our study revealed that HDAC9 silencing could retard ischemic brain injury through the miR-20a/Neurod1 signaling.

Stroke Microsurgical Thrombectomy Human Placenta Simulator

BACKGROUND

Stroke microsurgical cerebrovascular thrombectomy reports are limited, although this technique could be used in many centers as a primary treatment or a salvage intervention option. It requires great ability, so our aim is to describe and validate a stroke microsurgical thrombectomy ex vivo simulator with operative nuances analysis.

METHODS

Human placenta (HP) models simulated middle cerebral artery vessels with intraluminal thrombus to be microsurgically excised. Six neurosurgeons performed 1-mm and 2-mm longitudinal and transverse arteriotomy in different arteries to remove a 1.5-cm length thrombus. Validation through construct validity compared time to complete the task, complete vessel cleaning, vessel manipulation, vessel stenosis, and leakage in both techniques.

RESULTS

All 6 HP models reproduced with fidelity stroke microsurgical thrombectomy, so participants completed 24 sessions, 4 for each neurosurgeon on the same model in different arteries. Construct validity highlighted microsurgical technical difficulties with positive results obtained by parameters variation during performance. Transverse arteriotomy with 1-mm length had best results (P < 0.05) allowing complete thrombus removal, less stenosis, and minor leakage in abbreviated time.

CONCLUSIONS

A HP simulator can reproduce with high fidelity all stroke microsurgical thrombectomy part tasks. Transverse 1-mm arteriotomy followed by thrombectomy and 2 simple sutures can fulfill all quality assurance aspects in such intervention accordingly to training model, due to easier vessel opening, complete thrombus removal, no stenosis, and faster microsuture.

Theta-burst transcranial magnetic stimulation promotes stroke recovery by vascular protection and neovascularization

Rationale: The integrity and function of the blood-brain barrier (BBB) is compromised after stroke. The current study was performed to examine potential beneficial effects and underlying mechanisms of repetitive transcranial magnetic stimulation (rTMS) on angiogenesis and vascular protection, function, and repair following stroke, which are largely unknown.

Methods: Using a rat photothrombotic (PT) stroke model, continuous theta-burst rTMS was administered once daily to the infarcted hemisphere for 5 min, beginning 3 h after PT stroke. This treatment was applied for 6 days. BBB integrity, blood flow, vascular associated proteins, angiogenesis, integrity of neuronal morphology and structure, and behavioral outcome were measured and analyzed at 6 and/or 22 days after PT stroke.

Results: We report that rTMS significantly mitigated BBB permeabilization and preserved important BBB components ZO-1, claudin-5, occludin, and caveolin-1 from PT-induced degradation. Damage to vascular structure, morphology, and perfusion was ameliorated by rTMS, resulting in improved local tissue oxygenation. This was accompanied with robust protection of critical vascular components and upregulation of regulatory factors. A complex cytokine response was induced by PT, particularly at the late phase. Application of rTMS modulated this response, ameliorating levels of cytokines related to peripheral immune cell infiltration. Further investigation revealed that rTMS promoted and sustained post-ischemic angiogenesis long-term and reduced apoptosis of newborn and existing vascular endothelial cells. Application of rTMS also inhibited PT-induced excessive astrocyte-vasculature interactions and stimulated an A1 to A2 shift in vessel-associated astrocytes. Mechanistic studies revealed that rTMS dramatically increased levels of PDGFRβ associated with A2 astrocytes and their adjacent vasculature. As well, A2 astrocytes displayed marked amplification of the angiogenesis-related factors VEGF and TGFβ. PT induced a rise in vessel-associated expression of HIF-1α that was starkly intensified by rTMS treatment. Finally, rTMS preserved neuronal morphology, synaptic structure integrity and behavioral outcome.

Conclusions: These results indicate that rTMS can exert powerful protective and restorative effects on the peri-infarct microvasculature after PT stroke by, in part, promoting HIF-1α signaling and shifting vessel-associated astrocytic polarization to the A2 phenotype. This study provides further support for the potent protective effects of rTMS in the context of ischemic stroke, and these findings implicate vascular repair and protection as an important underlying phenomenon.

Beneficial Effects of Theta-Burst Transcranial Magnetic Stimulation on Stroke Injury via Improving Neuronal Microenvironment and Mitochondrial Integrity

Recent work suggests that repetitive transcranial magnetic stimulation (rTMS) may beneficially alter the pathological status of several neurological disorders, although the mechanism remains unclear. The current study was designed to investigate the effects of rTMS on behavioral deficits and potential underlying mechanisms in a rat photothrombotic (PT) stroke model. From day 0 (3 h) to day 5 after the establishment of PT stroke, 5-min daily continuous theta-burst rTMS (3 pulses of 50 Hz repeated every 200 ms, intensity at 200 G) was applied on the infarct hemisphere. We report that rTMS significantly attenuated behavioral deficits and infarct volume after PT stroke. Further investigation demonstrated that rTMS remarkably reduced synaptic loss and neuronal degeneration in the peri-infarct cortical region. Mechanistic studies displayed that beneficial effects of rTMS were associated with robust suppression of reactive micro/astrogliosis and the overproduction of pro-inflammatory cytokines, as well as oxidative stress and oxidative neuronal damage especially at the late stage following PT stroke. Intriguingly, rTMS could effectively induce a shift in microglial M1/M2 phenotype activation and an A1 to A2 switch in astrocytic phenotypes. In addition, the release of anti-inflammatory cytokines and mitochondrial MnSOD in peri-infarct regions were elevated following rTMS treatment. Finally, rTMS treatment efficaciously preserved mitochondrial membrane integrity and suppressed the intrinsic mitochondrial caspase-9/3 apoptotic pathway within the peri-infarct cortex. Our novel findings indicate that rTMS treatment exerted robust neuroprotection when applied at least 3 h after ischemic stroke. The underlying mechanisms are partially associated with improvement of the local neuronal microenvironment by altering inflammatory and oxidative status and preserving mitochondrial integrity in the peri-infarct zone. These findings provide strong support for the promising therapeutic effect of rTMS against ischemic neuronal injury and functional deficits following stroke.