Bihemispheric ischemic strokes in patients with COVID-19

Vestibular function is associated with immune inflammatory response

Association between vestibular function and immune inflammatory response has garnered increasing interest. Immune responses can lead to anatomical or functional alterations of the vestibular system, and inflammatory reactions may impair hearing and balance. Vestibular disorders comprise a variety of conditions, such as vestibular neuritis, benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine, posterior circulation ischemia, and bilateral vestibular disease. Moreover, some patients with autoimmune diseases develop vestibulocochlear symptom. This paper offers an overview of prevalent vestibular diseases and discusses associations between vestibular dysfunction and immune diseases.

Epidemiology, pathogenesis, and management of Coronavirus disease 2019-associated stroke

The Coronavirus disease 2019 (COVID-19) epidemic has triggered a huge impact on healthcare, socioeconomics, and other aspects of the world over the past three years. An increasing number of studies have identified a complex relationship between COVID-19 and stroke, although active measures are being implemented to prevent disease transmission. Severe COVID-19 may be associated with an increased risk of stroke and increase the rates of disability and mortality, posing a serious challenge to acute stroke diagnosis, treatment, and care. This review aims to provide an update on the influence of COVID-19 itself or vaccines on stroke, including arterial stroke (ischemic stroke and hemorrhagic stroke) and venous stroke (cerebral venous thrombosis). Additionally, the neurovascular mechanisms involved in SARS-CoV-2 infection and the clinical characteristics of stroke in the COVID-19 setting are presented. Evidence on vaccinations, potential therapeutic approaches, and effective strategies for stroke management has been highlighted.

Bridging the Gap: Investigating the Link between Inflammasomes and Postoperative Cognitive Dysfunction

Postoperative cognitive dysfunction (POCD) is a cluster of cognitive problems that may arise after surgery. POCD symptoms include memory loss, focus inattention, and communication difficulties. Inflammasomes, intracellular multiprotein complexes that control inflammation, may have a significant role in the development of POCD. It has been postulated that the NLRP3 inflammasome promotes cognitive impairment by triggering the inflammatory response in the brain. Nevertheless, there are many gaps in the current literature to understand the underlying pathophysiological mechanisms and develop future therapy. This review article underlines the limits of our current knowledge about the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome and POCD. We first discuss inflammasomes and their types, structures, and functions, then summarize recent evidence of the NLRP3 inflammasome's involvement in POCD. Next, we propose a hypothesis that suggests the involvement of inflammasomes in multiple organs, including local surgical sites, blood circulation, and other peripheral organs, leading to systemic inflammation and subsequent neuronal dysfunction in the brain, resulting in POCD. Research directions are then discussed, including analyses of inflammasomes in more clinical POCD animal models and clinical trials, studies of inflammasome types that are involved in POCD, and investigations into whether inflammasomes occur at the surgical site, in circulating blood, and in peripheral organs. Finally, we discuss the potential benefits of using new technologies and approaches to study inflammasomes in POCD. A thorough investigation of inflammasomes in POCD might substantially affect clinical practice.

Poststroke Mania During the COVID-19 Pandemic

ABSTRACT

The pandemic of coronavirus infection 2019 (COVID-19) is stressing people's daily lives and making them more susceptible to various mental illnesses. Depression and suicide attempt as well as, strangely enough, manic patients are on the rise. The main complication of COVID-19 infection is ischemic stroke. Multiple lacunar infarcts in the white matter of the right middle cerebral artery region induce an imbalance of blood flow in the left and right cerebral cortex and risk causing mania. The increase in mania during the COVID-19 must be considered not only a primary increase due to stress but also poststroke mania secondary to COVID-19 infection.

Phenothiazines reduced autophagy in ischemic stroke through endoplasmic reticulum (ER) stress-associated PERK-eIF2α pathway

BACKGROUND

Neuroprotective effects have been the main focus of new treatment modalities for ischemic stroke. Phenothiazines, or chlorpromazine plus promethazine (C + P), are known to prevent the generation of free radicals and uptake of Ca2+ by plasma membrane; they have a potential as a treatment for acute ischemic stroke (AIS). This study aims to investigate the role of endoplasmic reticulum (ER) stress-associated PERK-eIF2α pathway underlying the phenothiazine-induced neuroprotective effects after cerebral ischemia/reperfusion (I/R) injury.

METHODS

A total of 49 male Sprague Dawley rats (280-320 g) were randomly divided into 4 groups (n = 7 per group): (1) sham, (2) I/R that received 2 h of middle cerebral artery occlusion (MCAO), followed by 6 or 24 h of reperfusion, (3) MCAO treated by C + P without temperature control and (4) MCAO treated by C + P with temperature control. Human neuroblastoma (SH-SY5Y) cells were used in 5 groups: (1) control, (2) oxygen-glucose deprivation (OGD) for 2 h followed by reoxygenation (OGD/R), (3) OGD/R with C + P; (4) OGD/R with PERK inhibitor, GSK2656157, and (5) OGD/R with C + P and GSK2656157. The molecules of ER stress, unfolded protein response (UPR) (Bip, PERK, p-PERK, p-PERK/PERK, eIF2α, p-eIF2α, p-eIF2α/eIF2α), autophagy (ATG12, LC3II/I), and apoptosis (BAX, Bcl-XL) were measured at mRNA levels by real time PCR and protein levels by Western blotting.

RESULTS

In ischemic rats followed by reperfusion, expression of Bip, p-PERK/PERK, p-eIF2α/eIF2α, ATG12, and LC3II/I, as well as BAX were all significantly increased. These markers were significantly reduced by C + P at both 6 and 24 h of reperfusion. Anti-apoptotic Bcl-XL expression was increased, while pro-apoptotic BAX expression was decreased by C + P. In SH-SY5Y cell lines, both C + P and GSK2656157 significantly reduced the level of autophagy and apoptosis after I/R, respectively. The combination of GSK2656157 and C + P did not promote the same effect, suggesting that C + P did not induce any neuroprotective effect by inhibiting autophagy and apoptosis through the PERK-eIF2α pathway when this pathway was already blocked by GSK2656157. In general, the reduction in body temperature by phenothiazines was associated with better neuroprotection but it did not reach significant levels.

CONCLUSION

The combined treatment of C + P plays a crucial role in stroke therapy by inhibiting ER stress-mediated autophagy, thereby leading to reduced apoptosis and increased neuroprotection. Our findings highlight the PERK-eIF2α pathway as a central mechanism through which C + P exerts its beneficial effects. The results from this study may pave the way for the development of more targeted and effective treatments for stroke patients.

Identification of brain endothelial cell-specific genes and pathways in ischemic stroke by integrated bioinformatical analysis

BACKGROUND

Ischemic stroke (IS) is a life-threatening condition with limited treatment options; thus, finding the potential key genes for novel therapeutic targets is urgently needed. This study aimed to explore novel candidate genes and pathways of brain microvessel endothelial cells (ECs) in IS by bioinformatics analysis.

MATERIALS AND METHODS

The gene expression profiles of brain tissues or brain ECs in IS mice were downloaded from the online gene expression omnibus (GEO) to obtain the differentially expressed genes (DEGs) by R software. Functional enrichment analyses were used to cluster the functions and signaling pathways of the DEGs, while DEG-associated protein-protein interaction network was performed to identify hub genes. The target microRNAs and competitive endogenous RNA networks of key hub genes were constructed by Cytoscape.

RESULTS

Totally 84 DEGs were obtained from 6 brain tissue samples and 4 brain vascular EC samples both from IS mice in the datasets GSE74052 and GSE137482, with significant enrichment in immune responses, such as immune system processes and T-cell activation. Eight hub genes filtered by Cytoscape were validated by two other GEO datasets, wherein key genes of interest were verified by reverse transcription-polymerase chain reaction using an in vitro ischemic model of EC cultures. Our data indicated that AURKA and CENPF might be potential therapeutic target genes for IS, and Malat1/Snhg12/Xist-miR-297b-3p-CENPF, as well as Mir17 hg-miR-34b-3p-CENPF, might be RNA regulatory pathways to control IS progression.

CONCLUSIONS

Our work identified two brain EC-specific expressed genes in IS, namely, AURKA and CENPF, as potential gene targets for IS treatment. In addition, we presented miR-297b-3p/miR-34b-3p-CENPF as the potential RNA regulatory axes to prevent pathogenesis of IS.

Restlessness with manic episodes induced by right-sided multiple strokes after COVID-19 infection: A case report

Ischemic stroke is a major complication of coronavirus infection 2019 (COVID-19). During the COVID-19 pandemic, multiple strokes occurred in many elderly people. Among them, poststroke mood disorders such as depression are relatively common. However, restlessness with manic episodes has rarely been reported. We experienced an elderly patient who became manic shortly after recovering from COVID-19 infection, which turned out to be right-sided multiple strokes. The manic state improved as the strokes stabilized, suggesting that impaired blood flow was the cause of the manic symptoms. Primary mania increases blood flow in the left hemisphere, whereas right-sided strokes may relatively increase blood flow in the left hemisphere, which may have induced manic symptoms in this case. Multiple right-sided strokes after COVID-19 infection can cause mania, and the mechanism of poststroke mania needs to be investigated in the future.