Acute Viral Illnesses and Ischemic Stroke: Pathophysiological Considerations in the Era of the COVID-19 Pandemic

Discovery of a new long COVID mouse model via systemic histopathological comparison of SARS-CoV-2 intranasal and inhalation infection

Intranasal infection is commonly used to establish a SARS-CoV-2 mouse model due to its non-invasive procedures and a minimal effect from the operation itself. However, mice intranasally infected with SARS-CoV-2 have a high mortality rate, which limits the utility of this model for exploring therapeutic strategies and the sequelae of non-fatal COVID-19 cases. To resolve these limitations, an aerosolised viral administration method has been suggested. However, an in-depth pathological analysis comparing the two models is lacking. Here, we show that inhalation and intranasal SARS-CoV-2 (106 PFU) infection models established in K18-hACE2 mice develop unique pathological features in both the respiratory and central nervous systems, which could be directly attributed to the infection method. While the inhalation-infection model exhibited relatively milder pathological parameters, it closely mimicked the prevalent chest CT pattern observed in COVID-19 patients with focal, peripheral lesions and fibrotic scarring in the recuperating lung. We also found the evidence of direct neuron-invasion from the olfactory receptor neurons to the olfactory bulb in the intranasal model and showed the trigeminal nerve as an alternative route of transmission to the brain in inhalation infected mice. Even after viral clearance confirmed at 14 days post-infection, mild lesions were still found in the brain of inhalation-infected mice. These findings suggest that the inhalation-infection model has advantages over the intranasal-infection model in closely mimicking the pathological features of non-fatal symptoms of COVID-19, demonstrating its potential to study the sequelae and possible interventions for long COVID.

Co-administration of the adjuvanted recombinant zoster vaccine with other adult vaccines: An overview

BACKGROUND

The adjuvanted recombinant zoster vaccine (RZV; Shingrix®, GSK) is a subunit vaccine that has been approved for the prevention of herpes zoster in adults. Co-administration of two vaccines in a single visit is a strategy to improve overall vaccine coverage.

OBJECTIVES

This review aims to consolidate available clinical data on RZV co-administration, providing an overview of safety, reactogenicity and immunogenicity.

METHODS

RZV co-administration data were obtained from five randomised, open-label, phase III clinical trials with similar study designs. The co-administered vaccines included: quadrivalent seasonal inactivated influenza vaccine (IIV4; NCT01954251), 23-valent pneumococcal polysaccharide vaccine (PPSV23; NCT02045836), reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine (Tdap; NCT02052596), 13-valent pneumococcal conjugate vaccine (PCV13; NCT03439657) and COVID-19 mRNA-1273 booster (NCT05047770). Eligible participants were healthy adults aged ≥50 years.

RESULTS

A total of 3,974 participants were vaccinated (co-administration: 1,973; sequential: 2,001) across the five trials. Vaccine response rates to RZV were similar for co-administration (range: 95.8-99.1 %) and sequential groups (range: 95.1-99.1 %). Immune responses to RZV and the other vaccines (with the exception of pertactin) were non-inferior when the vaccines were co-administered compared with sequentially administered. Overall incidences of solicited local and general adverse events (AEs), unsolicited AEs, serious AEs or potential immune-mediated diseases were similar after co-administration or sequential administration. Myalgia was the most common solicited systemic AE (co-administration: 38-64 %; sequential: 30-59 %). Shivering and fever were more common after co-administration (16 % and 21 %, respectively) than after sequential administration (both 7 %) of RZV and PPSV23.

CONCLUSIONS

Co-administration of RZV with routine vaccines does not significantly alter the reactogenicity, immunogenicity or safety of RZV or the co-administered vaccine. Healthcare practitioners should consider routine co-administration of RZV with other adult vaccines to improve vaccination coverage.

Acute ischemic stroke outcomes in patients with COVID-19: a systematic review and meta-analysis

BACKGROUND

Although patients with COVID-19 have a higher risk of acute ischemic stroke (AIS), the impact on stroke outcomes remains uncertain.

AIMS

To determine the clinical outcomes of patients with AIS and COVID-19 (AIS-COVID+).

METHODS

We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Our protocol was registered with the International Prospective Register of Systematic Reviews (CRD42020211977). Systematic searches were last performed on June 3, 2021 in EMBASE, PubMed, Web-of-Science, Scopus, and CINAHL Databases.

INCLUSION CRITERIA

(1) studies reporting outcomes on AIS-COVID+; (2) original articles published in 2020 or later; (3) study participants aged ≥18 years.

EXCLUSION CRITERIA

(1) case reports with <5 patients, abstracts, review articles; (2) studies analyzing novel interventions. Risk of bias was assessed using the Mixed Methods Appraisal Tool. Random-effects models estimated the pooled OR and 95% confidence intervals (95% CI) for mortality, modified Rankin Scale (mRS) score, length of stay (LOS), and discharge disposition.

RESULTS

Of the 43 selected studies, 46.5% (20/43) reported patients with AIS without COVID-19 (AIS-COVID-) for comparison. Random-effects model included 7294 AIS-COVID+ and 158 401 AIS-COVID-. Compared with AIS-COVID-, AIS-COVID+ patients had higher in-hospital mortality (OR=3.87 (95% CI 2.75 to 5.45), P<0.001), less mRS scores 0-2 (OR=0.53 (95% CI 0.46 to 0.62), P<0.001), longer LOS (mean difference=4.21 days (95% CI 1.96 to 6.47), P<0.001), and less home discharge (OR=0.31 (95% CI 0.21 to 0.47), P<0.001).

CONCLUSIONS

Patients with AIS-COVID had worse outcomes, with almost fourfold increased mortality, half the odds of mRS scores 0-2, and one-third the odds of home discharge. These findings confirm the significant impact of COVID-19 on early stroke outcomes.

The Impact of the COVID-19 Pandemic on the Incidence of Herpes Zoster: A Narrative Literature Review

Coronavirus disease 2019 (COVID-19) has had a broad impact on health services and health outcomes. During the pandemic, there were numerous reports of herpes zoster (HZ) in people with COVID-19 and in COVID-19 vaccine recipients. The aim of this review is to elucidate the global effects of the COVID-19 pandemic on HZ. It is postulated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces an immunosuppressive state that favours varicella zoster virus (VZV) reactivation. Three large cohort studies (a multinational study and studies from the USA and Spain) that excluded individuals vaccinated against HZ reported significantly increased risk of HZ following COVID-19 infection, especially in people aged ≥ 50 years. In contrast, a large study from Israel that did not consider HZ vaccination status reported no such increase. Cases of HZ following COVID-19 vaccination have been reported and may be the result of attenuated cell-mediated immunity. This phenomenon appears to vary by vaccine type. Some (but not all) large analyses have reported a significant positive relationship between receipt of mRNA vaccines for COVID-19 and development of HZ. These include analyses of health records databases in Israel and Hong Kong and of spontaneous case reports in the US Vaccine Adverse Event Reporting System (VAERS) database. Routine vaccinations, including shingles vaccine programmes, were disrupted by the COVID-19 pandemic. It is estimated that missed shingles vaccinations may have resulted in 63,117 avoidable HZ cases in the USA. Now that the World Health Organization has declared an end to the COVID-19 pandemic as a health emergency and routine vaccination services have resumed, there is a need to increase awareness of HZ and HZ vaccination.Graphical abstract available for this article.

New Directions in Infection-Associated Ischemic Stroke

The relationship between infections and stroke has not been fully characterized, probably delaying the development of specific treatments. This narrative review addresses mechanisms of stroke linked to infections, including hypercoagulability, endothelial dysfunction, vasculitis, and impaired thrombolysis. SARS-CoV-2, the virus that causes COVID-19, may promote the development of stroke, which may represent its most severe neurological complication. The development of specific therapies for infection-associated stroke remains a profound challenge. Perhaps the most important remaining issue is the distinction between infections that trigger a stroke versus infections that are truly incidental. This distinction likely requires the establishment of appropriate biomarkers, candidates of which are elevated levels of fibrin D-dimer and anticardiolipin/antiphospholipid antibodies. These candidate biomarkers might have potential use in identifying pathogenic infections preceding stroke, which is a precursor to establishing specific therapies for this syndrome.

Recombinant zoster vaccine in immunocompetent and immunocompromised adults: A review of clinical studies

Herpes zoster (HZ) is a debilitating vaccine-preventable disease. Impairment of cell-mediated immunity, as observed with aging and immunosuppressive disorders and therapies, increases risk. Recombinant zoster vaccine (RZV) is efficacious against HZ in adults aged ≥50 years in different settings, and in immunocompromised adults aged ≥18 years who are at increased risk of developing HZ. RZV is the first and only HZ vaccine approved for use in immunocompromised adults globally, including in Europe and the US. RZV has a clinically acceptable safety profile and elicits robust immune responses in adults aged ≥50 years, and in immunocompromised adults aged ≥18 years who are at increased risk of HZ. Additionally, RZV is efficacious against HZ complications such as post-herpetic neuralgia and HZ-related pain. This review updates knowledge from a randomized controlled trial setting on the efficacy, safety, immunogenicity, and impact on quality of life of RZV.

Continued Infarction Growth and Penumbral Consumption After Reperfusion in Vaccine-Naive Patients With COVID-19: A Case-Control Study

BACKGROUND. Neurologic sequelae of SARS-CoV-2 include potentially malignant cerebrovascular events arising from complex hemodynamic, hematologic, and inflammatory processes occurring in concert. OBJECTIVE. This study concerns the hypothesis that despite angiographic reperfusion COVID-19 promotes continued consumption of at-risk tissue volumes after acute ischemic stroke (AIS), yielding critical insights into prognostication and monitoring paradigms in vaccine-naive patients experiencing AIS. METHODS. This retrospective study compared 100 consecutive COVID-19 patients with AIS presenting between March 2020 and April 2021 with a contemporaneous cohort of 282 AIS patients without COVID-19. Reperfusion classes were dichotomized into positive (extended thrombolysis in cerebral ischemia [eTICI] score = 2c-3) and negative (eTICI score < 2c) groups. All patients underwent endovascular therapy after initial CT perfusion imaging (CTP) to document infarction core and total hypoperfusion volumes. RESULTS. Ten COVID-positive (mean age ± SD, 67 ± 12 years; seven men, three women) and 144 COVID-negative patients (mean age, 71 ± 16 years; 76 men, 68 women) undergoing endovascular reperfusion, with antecedent CTP and follow-up imaging, comprised the final dataset. Initial infarction core and total hypoperfusion volumes (mean ± SD) were 1.5 ± 18 mL and 85 ± 100 mL in COVID-negative patients and 30.5 ± 34 mL and 117 ± 80.5 mL in COVID-positive patients, respectively. Final infarction volumes were significantly larger in patients with COVID-19, with median volumes of 77.8 mL versus 18.2 mL among control patients (p = .01), as were normalized measures of infarction growth relative to baseline infarction volume (p = .05). In adjusted logistic parametric regression models, COVID positivity emerged as a significant predictor for continued infarct growth (OR, 5.10 [95% CI, 1.00-25.95]; p = .05). CONCLUSION. These findings support the potentially aggressive clinical course of cerebrovascular events in patients with COVID-19, suggesting greater infarction growth and ongoing consumption of at-risk tissues, even after angiographic reperfusion. CLINICAL IMPACT. SARS-CoV-2 infection may promote continued infarction progression despite angiographic reperfusion in vaccine-naive patients with large-vessel occlusion AIS. The findings carry potential implications for prognostication, treatment selection, and surveillance for infarction growth among revascularized patients in future waves of infection by novel viral strains.

Research progress of different components of PM2.5 and ischemic stroke

PM2.5 is a nonhomogeneous mixture of complex components produced from multiple sources, and different components of this mixture have different chemical and biological toxicities, which results in the fact that the toxicity and hazards of PM2.5 may vary even for the same mass of PM2.5. Previous studies on PM2.5 and ischemic stroke have reached different or even opposing conclusions, and considering the heterogeneity of PM2.5 has led researchers to focus on the health effects of specific PM2.5 components. However, due to the complexity of PM2.5 constituents, assessing the association between exposure to specific PM2.5 constituents and ischemic stroke presents significant challenges. Therefore, this paper reviews and analyzes studies related to PM2.5 and its different components and ischemic stroke, aiming to understand the composition of PM2.5 and identify its harmful components, elucidate their relationship with ischemic stroke, and thus provide some insights and considerations for studying the biological mechanisms by which they affect ischemic stroke and for the prevention and treatment of ischemic stroke associated with different components of PM2.5.

Sociodemographic Factors, Comorbidities, In-Hospital Complications, and Outcomes of Ischaemic Stroke Patients in the Context of the COVID-19 Pandemic in Lithuania: A Retrospective, Record-Based, Single-Centre Study

INTRODUCTION

The role of COVID-19 regarding in-hospital complications and poor outcomes for patients with ischaemic stroke (IS) is still important to explore. The aim of this study was to evaluate the risk of in-hospital lethality for IS patients respectively to their comorbidities and in-hospital complications in the context of the COVID-19 pandemic.

METHODS

We identified 1898 acute IS patients (749 men and 1149 women) admitted to the Lithuanian University of Health Sciences Kaunas Hospital, Lithuania, from December 2020 to February 2022. The sociodemographic, clinical, and outcome features of the patients were evaluated deploying appropriate statistical tests. Hazard ratios and 95% confidence intervals were estimated by the Cox proportional hazards regression for hospital lethality.

RESULTS

The risk of in-hospital lethality was 2.22 times higher in men suffering from IS and chronic ischaemic heart disease (cIHD) compared to those with IS and isolated arterial hypertension (iAH) (p < 0.05). COVID-19 elevated the risk of in-hospital lethality in men by 3.16 times (p < 0.05). In comorbid women with type two diabetes mellitus (DM) or cIHD, the risk of in-hospital lethality was two times higher compared to those with iAH (p < 0.05). The risk of in-hospital lethality increased significantly in both men and women, with the total number of in-hospital complications increasing per one unit.

CONCLUSIONS

Of the comorbidities studied, DM and cIHD together with COVID-19 elevated the risk of in-hospital lethality significantly. Within the acute in-hospital complications, pneumonia with respiratory failure and acute renal failure showed the most significant prognostic value anticipating lethal outcomes for IS patients.

Genetic Architecture of Ischaemic Strokes after COVID-19 Shows Similarities with Large Vessel Strokes

We aimed to analyse whether patients with ischaemic stroke (IS) occurring within eight days after the onset of COVID-19 (IS-COV) are associated with a specific aetiology of IS. We used SUPERGNOVA to identify genome regions that correlate between the IS-COV cohort (73 IS-COV cases vs. 701 population controls) and different aetiological subtypes. Polygenic risk scores (PRSs) for each subtype were generated and tested in the IS-COV cohort using PRSice-2 and PLINK to find genetic associations. Both analyses used the IS-COV cohort and GWAS from MEGASTROKE (67,162 stroke patients vs. 454,450 population controls), GIGASTROKE (110,182 vs. 1,503,898), and the NINDS Stroke Genetics Network (16,851 vs. 32,473). Three genomic regions were associated (p-value < 0.05) with large artery atherosclerosis (LAA) and cardioembolic stroke (CES). We found four loci targeting the genes PITX2 (rs10033464, IS-COV beta = 0.04, p-value = 2.3 × 10-2, se = 0.02), previously associated with CES, HS6ST1 (rs4662630, IS-COV beta = -0.04, p-value = 1.3 × 10-3, se = 0.01), TMEM132E (rs12941838 IS-COV beta = 0.05, p-value = 3.6 × 10-4, se = 0.01), and RFFL (rs797989 IS-COV beta = 0.03, p-value = 1.0 × 10-2, se = 0.01). A statistically significant PRS was observed for LAA. Our results suggest that IS-COV cases are genetically similar to LAA and CES subtypes. Larger cohorts are needed to assess if the genetic factors in IS-COV cases are shared with the general population or specific to viral infection.

Ischemic strokes in COVID-19: risk factors, obesity paradox, and distinction between trigger and causal association

Background and purpose

Stroke has been described as a COVID-19 complication. However, its occurrence rate, risk factors, and causal relationships are still not well established.

Methods

We describe the characteristics of confirmed COVID-19-related strokes among all cases of COVID-19 hospitalized in our health network, from November 1, 2020 to April 30, 2021. Risk factor analysis has been conducted for ischemic stroke (IS), which represents 92% of all confirmed cases of Covid-19-related strokes, and a "causal attribution to infection" classification is provided.

Results

In all, 62/4105 hospitalized COVID-19 patients had an acute stroke (1.51%). Severe COVID-19 (OR 2.27-CI 1.06-4.77; p = 0.032), atrial fibrillation (OR 3.65-CI 1.63-7.98; p = 0.001), and ischemic heart disease (OR 4.590-CI 1.714-12.137; p = 0.002) proved to be independent risk factors for IS, while obesity was a protective factor (OR 0.90-CI 0.82-0.97; p = 0.012). COVID-19 had a causal role in 32.1% of IS cases, was a relevant cofactor in 28.6% of cases of IS, and was a possible trigger in 39.3% of events.

Conclusion

Our stroke occurrence rate is consistent with other population-based reports (range 0.34-2.7%). Prespecified peculiar clinical and radiological features allow the distinction between "IS caused by COVID-19" and "IS triggered by COVID-19." Clinical history of vascular diseases and risk factors is crucial in determining the risk of IS in patients with COVID-19. However, the protective effect of a BMI > 30 kg/m2 seems to suggest an obesity paradox.

Epigenome-wide association study identifies novel genes associated with ischemic stroke

BACKGROUND

DNA methylation has previously been associated with ischemic stroke, but the specific genes and their functional roles in ischemic stroke remain to be determined. Here we aimed to identify differentially methylated genes that play a functional role in ischemic stroke in a Chinese population.

RESULTS

Genome-wide DNA methylation assessed with the Illumina Methylation EPIC Array in a discovery sample including 80 Chinese adults (40 cases vs. 40 controls) found that patients with ischemic stroke were characterized by increased DNA methylation at six CpG loci (individually located at TRIM6, FLRT2, SOX1, SOX17, AGBL4, and FAM84A, respectively) and decreased DNA methylation at one additional locus (located at TLN2). Targeted bisulfite sequencing confirmed six of these differentially methylated probes in an independent Chinese population (853 cases vs. 918 controls), and one probe (located at TRIM6) was further verified in an external European cohort (207 cases vs. 83 controls). Experimental manipulation of DNA methylation in engineered human umbilical vein endothelial cells indicated that the identified differentially methylated probes located at TRIM6, TLN2, and FLRT2 genes may play a role in endothelial cell adhesion and atherosclerosis.

CONCLUSIONS

Altered DNA methylation of the TRIM6, TLN2, and FLRT2 genes may play a functional role in ischemic stroke in Chinese populations.

The Spectrum of Pediatric Infection-Associated Intracranial Arteriopathies and Acute Ischemic Stroke at 2 Eastern Indian Tertiary Care Centres

INTRODUCTION

Major and minor pediatric infections may cause intracranial arteriopathies, the long-term outcome of which we investigated and identified the factors influencing the progression/resolution of arteriopathies.

METHODS

We collected the clinical and radiological data of children aged 1 month-15 years who had ischemic stroke with definite arteriopathy following a recent febrile infection. Repeated neuroimaging was done over the next year to ascertain recurrent strokes and the progression and resolution of arteriopathies.

RESULTS

The anterior circulation was more frequently affected (83.33%), predominantly involving the middle cerebral artery (41.67%), resolving in 20.84% of cases and progressing in 33.33% of cases. Lesions were commonly unilateral (54.17%) and stenotic (75%), resulting predominantly in cortical infarcts (45.83%), with hemiparesis being the most common neurodeficiency. Apart from tubercular meningitis patients, others had a good functional outcome.

CONCLUSION

Lower age, minor infections, and unilateral arteriopathies had a significantly higher chance of resolution. Postviral arteriopathies had a significantly lower chance of progression compared with those following bacterial infections. Progressive and bilateral arteriopathies were significantly associated with worse outcomes and recurrent strokes.

Increased stroke severity and mortality in patients with SARS-CoV-2 infection: An analysis from the N3C database

BACKGROUND

Studies from early in the COVID-19 pandemic showed that patients with ischemic stroke and concurrent SARS-CoV-2 infection had increased stroke severity. We aimed to test the hypothesis that this association persisted throughout the first year of the pandemic and that a similar increase in stroke severity was present in patients with hemorrhagic stroke.

METHODS

Using the National Institute of Health National COVID Cohort Collaborative (N3C) database, we identified a cohort of patients with stroke hospitalized in the United States between March 1, 2020 and February 28, 2021. We propensity score matched patients with concurrent stroke and SARS-COV-2 infection and available NIH Stroke Scale (NIHSS) scores to all other patients with stroke in a 1:3 ratio. Nearest neighbor matching with a caliper of 0.25 was used for most factors and exact matching was used for race/ethnicity and site. We modeled stroke severity as measured by admission NIHSS and the outcomes of death and length of stay. We also explored the temporal relationship between time of SARS-COV-2 diagnosis and incidence of stroke.

RESULTS

Our query identified 43,295 patients hospitalized with ischemic stroke (5765 with SARS-COV-2, 37,530 without) and 18,107 patients hospitalized with hemorrhagic stroke (2114 with SARS-COV-2, 15,993 without). Analysis of our propensity matched cohort revealed that stroke patients with concurrent SARS-COV-2 had increased NIHSS (Ischemic stroke: IRR=1.43, 95% CI:1.33-1.52, p<0.001; hemorrhagic stroke: IRR=1.20, 95% CI:1.08-1.33, p<0.001), length of stay (Ischemic stroke: estimate = 1.48, 95% CI: 1.37, 1.61, p<0.001; hemorrhagic stroke: estimate = 1.25, 95% CI: 1.06, 1.47, p=0.007) and higher odds of death (Ischemic stroke: OR 2.19, 95% CI: 1.79-2.68, p<0.001; hemorrhagic stroke: OR 2.19, 95% CI: 1.79-2.68, p<0.001). We observed the highest incidence of stroke diagnosis on the same day as SARS-COV-2 diagnosis with a logarithmic decline in counts.

CONCLUSION

This retrospective observational analysis suggests that stroke severity in patients with concurrent SARS-COV-2 was increased throughout the first year of the pandemic.

Trends in Intensive Care Admissions and Outcomes of Stroke Patients Over 10 Years in Brazil: Impact of the COVID-19 Pandemic

BACKGROUND

The coronavirus 2019 (COVID-19) pandemic affected stroke care worldwide. Data from low- and middle-income countries are limited.

RESEARCH QUESTION

What was the impact of the pandemic in ICU admissions and outcomes of patients with stroke, in comparison with trends over the last 10 years?

STUDY DESIGN AND METHODS

Retrospective cohort study including prospectively collected data from 165 ICUs in Brazil between 2011 and 2020. We analyzed clinical characteristics and mortality over a period of 10 years and evaluated the impact of the pandemic on stroke outcomes, using the following approach: analyses of admissions for ischemic and hemorrhagic strokes and trends in in-hospital mortality over 10 years; analysis of variable life-adjusted display (VLAD) during 2020; and a mixed-effects multivariable logistic regression model.

RESULTS

A total of 17,115 stroke admissions were analyzed, from which 13,634 were ischemic and 3,481 were hemorrhagic. In-hospital mortality was lower after ischemic stroke as compared with hemorrhagic (9% vs 24%, respectively). Changes in VLAD across epidemiological weeks of 2020 showed that the rise in COVID-19 cases was accompanied by increased mortality, mainly after ischemic stroke. In logistic regression mixed models, mortality was higher in 2020 compared with 2019, 2018, and 2017 in patients with ischemic stroke, namely, in those without altered mental status. In hemorrhagic stroke, the increased mortality in 2020 was observed in patients 50 years of age or younger, as compared with 2019.

INTERPRETATION

Hospital outcomes of stroke admissions worsened during the COVID-19 pandemic, interrupting a trend of improvements in survival rates over 10 years. This effect was more pronounced during the surge of COVID-19 ICU admissions affecting predominantly patients with ischemic stroke without coma, and young patients with hemorrhagic stroke.

Risk of, and risk factors for, vasculopathy associated with acute herpes zoster

OBJECTIVES

We aimed to summarize the known risk of vasculopathy (stroke, myocardial infarction [MI], and transient ischemic attack [TIA]) after herpes zoster (HZ) and the impact of antiviral treatment and vaccination against HZ on the risk of vasculopathy.

MATERIALS AND METHODS

A narrative literature review was conducted in PubMed to identify evidence published in the past 15 years that was relevant to the scope of this article.

RESULTS

Ten studies reported that HZ was associated with an increased risk of stroke and one UK study reported no association. Four studies reported that HZ was associated with an increased risk of MI, and four reported that HZ was associated with an increased risk of TIA. Two studies reported that antiviral treatment was associated with a reduced risk of stroke and an additional two studies reported no association between antiviral treatment and the risk of stroke. In addition, two studies reported that vaccination against HZ using the live zoster vaccine (ZVL) was associated with a reduced risk of stroke, and an additional two studies reported that the risk of stroke or MI after HZ was similar between ZVL vaccinated and unvaccinated individuals.

CONCLUSIONS

HZ is associated with an increased risk of stroke, MI, or TIA (strongest association is between HZ and stroke). Further studies are needed to determine whether antiviral treatment or ZVL vaccination influence the risk of HZ-associated vasculopathy. In addition, the effect of the recombinant zoster vaccine on the risk of HZ-associated vasculopathy should be studied.

Neurological Complications in Children Hospitalized With Seizures and Respiratory Infections: A Comparison Between SARS-CoV-2 and Other Respiratory Infections

BACKGROUND

Children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can experience neurological symptoms, but limited data are available on neurological symptoms associated with other respiratory infections. We compared proportions of neurological symptoms in children hospitalized with seizures and respiratory infections, including SARS-CoV-2, influenza, and endemic coronaviruses.

METHODS

A retrospective cohort study was performed on children admitted for seizures who had positive respiratory polymerase chain reactions for SARS-CoV-2, coronavirus NL63, coronavirus OC34, influenza (A and B), adenovirus, Mycoplasma pneumoniae, or parainfluenza 3 or 4. Primary outcomes were rates of new neurological diagnoses and mortality.

RESULTS

A total of 883 children were included. Mortality rates ranged from 0% with M. pneumoniae to 4.9% with parainfluenza 4. Strokes were observed with all infections except for coronavirus OC43 and M. pneumoniae, with the highest rates in parainfluenza 4 (4.9%) and SARS-CoV-2 (5.9%). Compared with other infections, children with SARS-CoV-2 were older, had higher rates of stroke, and lower rates of intubation. The most common brain magnetic resonance imaging (MRI) abnormality was diffusion restriction. Abnormal MRI rates were lower in SARS-CoV-2, compared with patients with other coronavirus (OC). However, rates of stroke, encephalopathy, hypoxic-ischemic encephalopathy, and meningoencephalitis were similar between SARS-CoV-2 and influenza cohorts.

CONCLUSIONS

In children hospitalized with seizures, higher rates of stroke were observed in SARS-CoV-2 versus OC. Similar rates of neurological symptoms were observed in patients with SARS-CoV-2 and those with influenza. Strokes can occur in children with these viral infections, particularly SARS-CoV-2.

International Controlled Study of Revascularization and Outcomes Following COVID-Positive Mechanical Thrombectomy

Background and purpose

Previous studies suggest that mechanisms and outcomes in patients with COVID‐19‐associated stroke differ from those in patients with non‐COVID‐19‐associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID‐19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors.

Methods

A cross‐sectional, international multicenter retrospective study was conducted in consecutively admitted COVID‐19 patients with concomitant acute LVO, compared to a control group without COVID‐19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable‐adjusted analysis was conducted.

Results

In this cohort of 697 patients with acute LVO, 302 had COVID‐19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID‐19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID‐19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23–0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12–0.77; p = 0.012). Moreover, endovascular complications, in‐hospital mortality, and length of hospital stay were significantly higher among COVID‐19 patients (p < 0.001).

Conclusion

COVID‐19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID‐19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Value of 4D CT Angiography Combined with Whole Brain CT Perfusion Imaging Feature Analysis under Deep Learning in Imaging Examination of Acute Ischemic Stroke

This study was aimed at investigating the application of deep learning 4D computed tomography angiography (CTA) combined with whole brain CT perfusion (CTP) imaging in acute ischemic stroke (AIS). A total of 46 patients with ischemic stroke were selected from the hospital as the research objects. Image quality was analyzed after the 4D CTA images were obtained by perfusion imaging. The results showed that whole brain perfusion imaging based on FCN can achieve automatic segmentation. FCN segmentation results took a short time, an average of 2-3 seconds, and the Dice similarity coefficient (DSC) and mean absolute distance (MAD) were lower than those of other algorithms. FCN segmentation distance was 17.87. The parameters of the central area, the peripheral area, and the mirror area of the perfusion map were compared, and the mean transit time (MTT) and time to peak (TTP) of the lesion were prolonged compared with the mirror area. Moreover, the peripheral CBV was increased, and the differences between the parameters were significant (P < 0.05). In conclusion, using the deep learning FCN network, 4D CTA combined with whole brain CTP imaging technology can effectively analyze the perfusion state and achieve clinically personalized treatment.

Characteristics of a COVID-19 Cohort With Large Vessel Occlusion: A Multicenter International Study

BACKGROUND

The mechanisms and outcomes in coronavirus disease (COVID-19)-associated stroke are unique from those of non-COVID-19 stroke.

OBJECTIVE

To describe the efficacy and outcomes of acute revascularization of large vessel occlusion (LVO) in the setting of COVID-19 in an international cohort.

METHODS

We conducted an international multicenter retrospective study of consecutively admitted patients with COVID-19 with concomitant acute LVO across 50 comprehensive stroke centers. Our control group constituted historical controls of patients presenting with LVO and receiving a mechanical thrombectomy between January 2018 and December 2020.

RESULTS

The total cohort was 575 patients with acute LVO; 194 patients had COVID-19 while 381 patients did not. Patients in the COVID-19 group were younger (62.5 vs 71.2; P < .001) and lacked vascular risk factors (49, 25.3% vs 54, 14.2%; P = .001). Modified thrombolysis in cerebral infarction 3 revascularization was less common in the COVID-19 group (74, 39.2% vs 252, 67.2%; P < .001). Poor functional outcome at discharge (defined as modified Ranklin Scale 3-6) was more common in the COVID-19 group (150, 79.8% vs 132, 66.7%; P = .004). COVID-19 was independently associated with a lower likelihood of achieving modified thrombolysis in cerebral infarction 3 (odds ratio [OR]: 0.4, 95% CI: 0.2-0.7; P < .001) and unfavorable outcomes (OR: 2.5, 95% CI: 1.4-4.5; P = .002).

CONCLUSION

COVID-19 was an independent predictor of incomplete revascularization and poor outcomes in patients with stroke due to LVO. Patients with COVID-19 with LVO were younger, had fewer cerebrovascular risk factors, and suffered from higher morbidity/mortality rates.

Shared genetic background between SARS-CoV-2 infection and large artery stroke

BACKGROUND AND AIMS

Increased risk of stroke, particularly large artery stroke (LAS), has been observed in patients with COVID-19. The biological processes underlying the observed higher risk are still unknown. We explored the association between stroke subtypes and COVID-19 susceptibility to understand whether biological mechanisms specific to SARS-CoV-2 uptake/infection could be leading to excess stroke risk in this population.

PATIENTS AND METHODS

We constructed a polygenic risk score (PRS) of COVID-19 susceptibility and tested its association with stroke subtypes using individual- and summary-level genetic data (SiGN, MEGASTROKE). We generated co-expression networks of genes involved in SARS-CoV-2 uptake/infection (ACE2, TMPRSS2, BEST3, ISLR2 and ADAM17) based on existing tissue expression libraries. Gene-based association testing was performed using S-PrediXcan and VEGAS2. Permutation independence tests were performed to assess SARS-CoV-2-related gene enrichment in stroke and its subtypes.

RESULTS

Our PRS demonstrated an association between COVID-19 susceptibility and LAS in SiGN (OR = 1.05 per SD increase, 95% CI: (1.00, 1.10), p = 0.04) and MEGASTROKE (β = 0.510, 95% CI: (0.242, 0.779), FDR-p = 0.0019). The SARS-CoV-2 risk-related ISLR2 co-expression gene network was significantly associated with genetic risk of LAS in aorta, tibial arteries, and multiple brain regions (P < 0.05).

CONCLUSION

Presence of genetic correlation and significant pathway enrichment suggest that increases in LAS risk reported in COVID-19 patients may be intrinsic to the viral infection, rather than a more generalized response to severe illness.

COVID-19 did not result in increased hospitalization for stroke and transient ischemic attack. A nationwide study

Background

The risk of thrombosis increases in infectious diseases, yet observational studies from single centers have shown a decrease in admission of acute ischemic stroke patients during the COVID‐19 pandemic. To investigate unselected stroke admission rates we performed a nationwide study in Denmark.

Methods

We extracted information from Danish national health registries. The following mutually exclusive time periods were compared to the year before the lockdown: (1) first national lockdown, (2) gradual reopening, (3) few restrictions, (4) regional lockdown, and (5) second national lockdown.

Results

Generally, admission rates were unchanged during the pandemic. In the unadjusted data, we observed a small decrease in the admission rate for all strokes under the first lockdown (incidence rate ratio: 0.93, confidence interval [CI]: 0.87–0.99) and a slight increase during the periods with gradual reopening, few restrictions, and the regional lockdown driven by ischemic strokes. We found no change in the rate of severe strokes, mild strokes, or 30‐day mortality. An exception was the higher mortality for all strokes during the first lockdown (risk ratio: crude 1.30 [CI: 1.03–1.59]; adjusted 1.17 [CI: 0.93–1.47]). The quality of care remained unchanged.

Conclusion

Stroke admission rates remained largely unchanged during the pandemic, while an increased short‐term mortality rate in patients admitted with stroke observed during the first lockdown was seen, probably reflecting that the more frail patients constituted a higher proportion of admitted patients at the beginning of the pandemic.

Ιmmunity, Vascular Aging, and Stroke

Stroke is one of the most devastating manifestations of cardiovascular disease. Growing age, arterial hypertension, and atherosclerosis are identified as independent risk factors for stroke, primarily due to structural and functional alterations in the cerebrovascular tree. Recent data from in vitro and clinical studies have suggested that the immune system influences atherosclerosis, promoting vascular stiffness and vascular aging and contributing to ischemic stroke, intracranial haemorrhage and microbleeds, white matter disease, and cognitive decline. Furthermore, aging is related to a chronic low-grade inflammatory state, in which macrophage, neutrophils, natural killer (NK cells), and B and T lymphocytes act as major effectors of the immune-mediated cell responses. Moreover, oxidative stress and vascular inflammation are correlated with endothelial dysfunction, vascular aging, blood-brain barrier disruption, lacunar lesions, and neurodegenerative disorders. This review discusses the pathophysiological roles of fundamental cellular and molecular mechanisms of aging, including the complex interplay between them and innate immunity, as well as vascular dysfunction, arterial stiffness, atherosclerosis, atherothrombosis, systemic inflammation, and blood-brain barrier dysfunction.