Influenza Virus Infection Aggravates Stroke Outcome

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.

COVID-19 and Neurological Manifestations

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a newly emerged coronavirus, has sparked a global pandemic with its airborne transmission and ability to infect with asymptomatic patients. The pathophysiology is thought to relate to the binding of angiotensin converting enzyme 2 (ACE2) receptors in the body. These receptors are widely expressed in various body organs such as the lungs, the heart, the gastrointestinal tract (GIT), and the brain. This article reviews the current knowledge on the symptoms of coronavirus disease 2019 (COVID-19), highlighting the neurological symptoms that are associated with COVID-19, and discussing the possible mechanisms for SARS-CoV-2 virus infection in the body.

SARS-CoV-2 infection increases risk of intracranial hemorrhage

Introduction

SARS-CoV-2 virus infection causes a dysbalanced and severe inflammatory response, including hypercytokinemia and immunodepression. Systemic inflammation triggered by a viral infection can potentially cause vascular damage, which may lead to cardiovascular and neurovascular events.

Research question

The aim was to investigate whether CNS complications are related to COVID-19.

Materials and methods

We examined 21 patients suffering from stroke and intracranial hemorrhage (ICH) and 9 (43%) of them were male. We compared relative frequencies using Fisher's exact test. As we had few observations and many variables, we used principal component analysis (PCA) to reduce data dimensionality. We trained a linear support vector machine (SVM) on the first two PCs of the laboratory data to predict COVID-19.

Results

Patients suffering from stroke had either hypertension or SARS-CoV-2 infection, but seldom both (OR = 0.05, p = 0.0075). The presence of SARS-CoV-2 infection was strongly associated with the logarithm of CRP (p = 1.4e-07) and with D-DIMER (p = 1.6e-05) and moderately with PT (p = 0.0024). SARS-CoV-2 infection was not related to any other factor. CRP, D-DIMER, PT, and INR were all related to each other (R 2 ranging from 0.19 to 0.52, p ranging from 0.012 to < 0.0001). The first two PCs covered 96% of the variance in the four variables. Using them, perfect linear discrimination between patients suffering from COVID-19 and other patients could be achieved.

Discussion and conclusion

SARS-CoV-2 infection causes systemic inflammation, which is suggested as a predictor of the severe course of ICH. SARS-CoV-2 infection is an additional risk factor for vascular complications.

Secondary Headache Disorders: Approach, Workup, and Special Considerations for Select Populations

Headache is one of the most common diagnoses in neurology. A thorough understanding of the clinical presentation of secondary headache, which can be life-threatening, is critical. This review provides an overview of the diagnostic approach to a patient with headache, including discussion of "red," "orange," and "green" flags. We emphasize particular scenarios to help tailor the clinical workup to individual circumstances such as in pregnant women, when particular attention must be paid to the effects of blood pressure and hypercoagulability, as well as in older adults, where there is a need for higher suspicion for an intracranial mass lesion or giant cell arteritis. Patients with risk factors for headache secondary to alterations in intracranial pressure, whether elevated (e.g., idiopathic intracranial hypertension) or decreased (e.g., cerebrospinal fluid leak), may require more specific diagnostic testing and treatment. Finally, headache in patients with COVID-19 or long COVID-19 is increasingly recognized and may have multiple etiologies.

Outcomes following diabetes admission in patients who had influenza vaccination: A population-based cohort study

OBJECTIVE

The beneficial effect of influenza vaccination (IV) in patients with diabetes was not completely understood.

METHODS

Using the research data of health insurance, we performed a cohort study of patients aged ≥20 years who were admitted to inpatient care due to diabetes in 2008-2013 in Taiwan. We performed the propensity score matching and the outcomes of complications and mortality following the diabetes admission was compared between patients with and without IV.

RESULTS

Among 61,002 patients with diabetes admission, IV reduced 30-day in-hospital mortality (odds ratio [OR] 0.75, 95% confidence interval [CI] 0.66-0.84), particularly among patients with prior diabetes hospitalization, inadequate control for diabetes, and diabetes-related comorbidities, such as eye involvement, ketoacidosis, renal manifestations, and coma. Compared with non-IV control group, patients with IV also had decreased risks of pneumonia (OR 0.92, 95% CI 0.87-0.97), septicemia (OR 0.83, 95% CI 0.79-0.88), urinary tract infection (OR 0.94, 95% CI 0.90-0.97), and intensive care (OR 0.29, 95% CI 0.27-0.31).

CONCLUSION

In patients with diabetes admission, IV was associated with reduced risks of complications and mortality. Our study implicated the urgent need to promote influenza vaccination for this susceptible population with diabetes.

Molecular mechanisms highlighting the potential role of COVID-19 in the development of neurodegenerative diseases

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to the pulmonary manifestations, COVID-19 patients may present a wide range of neurological disorders as extrapulmonary presentations. In this view, several studies have recently documented the worsening of neurological symptoms within COVID-19 morbidity in patients previously diagnosed with neurodegenerative diseases (NDs). Moreover, several cases have also been reported in which the patients presented parkinsonian features after initial COVID-19 symptoms. These data raise a major concern about the possibility of communication between SARS-CoV-2 infection and the initiation and/or worsening of NDs. In this review, we have collected compelling evidence suggesting SARS-CoV-2, as an environmental factor, may be capable of developing NDs. In this respect, the possible links between SARS-CoV-2 infection and molecular pathways related to most NDs and the pathophysiological mechanisms of the NDs such as Alzheimer's disease, vascular dementia, frontotemporal dementia, Parkinson's disease, and amyotrophic lateral sclerosis will be explained.

Intracranial Aneurysm Rupture after SARS-CoV2 Infection: Case Report and Review of Literature

Background: SARS-CoV virus infection results in a dysbalanced and severe inflammatory response with hypercytokinemia and immunodepression. Viral infection triggers systemic inflammation and the virus itself can potentially cause vascular damage, including blood–brain barrier (BBB) disruption and alterations in the coagulation system, which may result in cardiovascular and neurovascular events. Here, we review the literature and present a case of COVID-19 infection leading to an aneurysmal subarachnoid haemorrhage (aSAH). Case Description: A 61-year-old woman presented with dyspnea, cough, and fever. She had a history of hypertension and was overweight with a body mass-index of 34. There was no history of subarachnoid hemorrhage in the family. Due to low oxygen saturation (89%) she was admitted into ICU. A chest CT showed a typical picture of COVID-19 pneumonia. The PCR-based test of an oropharyngeal swab was COVID-19-positive. In addition to oxygen support she was prescribed with favipiravir and hydroxychloroquine. She experienced a sudden headache and lost consciousness on the second day. Computer tomography (CT) with CT-angiography revealed a subarachnoid haemorrhage in the basal cisterns from a ruptured anterior communicating artery aneurysm. The aneurysm was clipped microsurgically through a left-sided standard pterional approach and the patient was admitted again to the intensive care unit for further intensive medical treatment. Post-operatively, the patient showed slight motor dysphasia. No other neurological deficits. Conclusion: Systemic inflammation and ventilator support-associated blood pressure fluctuations may trigger aneurysmal subarachnoid haemorrhage secondary to COVID-19 infection. COVID-19 infection could be considered as one of the possible risk factors leading to instability and rupture of intracranial aneurysm.

Neuroinflammation, Stem Cells, and Stroke

Stroke remains a significant unmet clinical need with few treatment options that have a very narrow therapeutic window, thereby causing massive mortality and morbidity in the United States and around the world. Accordingly, finding safe and effective novel treatments with a wider therapeutic window stands as an urgent need in stroke. The progressive inflammation that occurs centrally and peripherally after stroke serves as a unique therapeutic target to retard and even halt the secondary cell death. Stem cell therapy represents a potent approach that can diminish inflammation in both the stroke brain and periphery (eg, spleen), advancing a paradigm shift from a traditionally brain-focused therapy to treating stroke as a neurological disorder with a significant peripheral pathology. The purpose of this review article is to highlight the inflammation-mediated secondary cell death that plagues both brain and spleen in stroke and to evaluate the therapeutic potential of stem cell therapy in dampening these inflammatory responses.

Infection, inflammation and thrombosis: a review of potential mechanisms mediating arterial thrombosis associated with influenza and severe acute respiratory syndrome coronavirus 2

Thrombosis has long been reported as a potentially deadly complication of respiratory viral infections and has recently received much attention during the global coronavirus disease 2019 pandemic. Increased risk of myocardial infarction has been reported during active infections with respiratory viruses, including influenza and severe acute respiratory syndrome coronavirus 2, which persists even after the virus has cleared. These clinical observations suggest an ongoing interaction between these respiratory viruses with the host's coagulation and immune systems that is initiated at the time of infection but may continue long after the virus has been cleared. In this review, we discuss the epidemiology of viral-associated myocardial infarction, highlight recent clinical studies supporting a causal connection, and detail how the virus' interaction with the host's coagulation and immune systems can potentially mediate arterial thrombosis.

Evidence of Coronavirus (CoV) Pathogenesis and Emerging Pathogen SARS-CoV-2 in the Nervous System: A Review on Neurological Impairments and Manifestations

The coronavirus disease 2019 (COVID-19) pandemic is an issue of global significance that has taken the lives of many across the world. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for its pathogenesis. The pulmonary manifestations of COVID-19 have been well described in the literature. Initially, it was thought to be limited to the respiratory system; however, we now recognize that COVID-19 also affects several other organs, including the nervous system. Two similar human coronaviruses (CoV) that cause severe acute respiratory syndrome (SARS-CoV-1) and Middle East respiratory syndrome (MERS-CoV) are also known to cause disease in the nervous system. The neurological manifestations of SARS-CoV-2 infection are growing rapidly, as evidenced by several reports. There are several mechanisms responsible for such manifestations in the nervous system. For instance, post-infectious immune-mediated processes, direct virus infection of the central nervous system (CNS), and virus-induced hyperinflammatory and hypercoagulable states are commonly involved. Guillain-Barré syndrome (GBS) and its variants, dysfunction of taste and smell, and muscle injury are numerous examples of COVID-19 PNS (peripheral nervous system) disease. Likewise, hemorrhagic and ischemic stroke, encephalitis, meningitis, encephalopathy acute disseminated encephalomyelitis, endothelialitis, and venous sinus thrombosis are some instances of COVID-19 CNS disease. Due to multifactorial and complicated pathogenic mechanisms, COVID-19 poses a large-scale threat to the whole nervous system. A complete understanding of SARS-CoV-2 neurological impairments is still lacking, but our knowledge base is rapidly expanding. Therefore, we anticipate that this comprehensive review will provide valuable insights and facilitate the work of neuroscientists in unfolding different neurological dimensions of COVID-19 and other CoV associated abnormalities.

The significant impact of Coronavirus disease 2019 (COVID-19) on in-hospital mortality of elderly patients with moderate to severe traumatic brain injury: A retrospective observational study

Background

 Traumatic brain injury (TBI) is one of the main causes of death and disability among the elderly patient population. This study aimed to assess the predictors of in-hospital mortality of elderly patients with moderate to severe TBI who presented during the Coronavirus disease 2019 (COVID-19) pandemic.

Methods

In this retrospective analytical study, all elderly patients with moderate to severe TBI who were referred to our center between March 2nd, 2020 to August 1st, 2020 were investigated and compared against the TBI patients receiving treatment during the same time period within the year 2019. Patients were followed until discharge from the hospital or death. The demographic, clinical, radiological, and laboratory test data were evaluated. Data were analyzed using SPSS-21 software.

Findings

In this study, 359 elderly patients were evaluated (n = 162, Post-COVID-19). Fifty-four patients of the cohort had COVID-19 disease with a mortality rate was 33.3%. The patients with COVID-19 were 5.45 times more likely to expire before discharge (P < 0.001) than the TBI patients who were not COVID-19 positive. Other variables such as hypotension (OR, 4.57P < 0.001), hyperglycemia (OR, 2.39, P = 0.002), and use of anticoagulant drugs (OR, 2.41P = 0.001) were also associated with in-hospital death. According to the binary logistic regression analysis Age (OR, 1.72; 95% CI: 1.26–2.18; P = 0.033), Coronavirus infection (OR, 2.21; 95% CI: 1.83–2.92; P = 0.011) and Glasgow Coma Scale (GCS) (OR, 3.11; 95% CI: 2.12–4.53; P < 0.001) were independent risk factors correlated with increased risk of in-hospital mortality of elderly patients with moderate to severe TBI.

Conclusion

Our results showed that Coronavirus infection could increase the risk of in-hospital mortality of elderly patients with moderate to severe TBI significantly.

Neuroinflammatory Triangle Presenting Novel Pharmacological Targets for Ischemic Brain Injury

Ischemic stroke is one of the leading causes of morbidity and mortality globally. Hundreds of clinical trials have proven ineffective in bringing forth a definitive and effective treatment for ischemic stroke, except a myopic class of thrombolytic drugs. That, too, has little to do with treating long-term post-stroke disabilities. These studies proposed diverse options to treat stroke, ranging from neurotropic interpolation to venting antioxidant activity, from blocking specific receptors to obstructing functional capacity of ion channels, and more recently the utilization of neuroprotective substances. However, state of the art knowledge suggests that more pragmatic focus in finding effective therapeutic remedy for stroke might be targeting intricate intracellular signaling pathways of the 'neuroinflammatory triangle': ROS burst, inflammatory cytokines, and BBB disruption. Experimental evidence reviewed here supports the notion that allowing neuroprotective mechanisms to advance, while limiting neuroinflammatory cascades, will help confine post-stroke damage and disabilities.

COVID-19 outbreak as a probable cause of increased risk of intracranial rebleeding in partially treated cerebral arteriovenous malformations

Patients who are infected with COVID-19 and have cerebral arteriovenous malformations which are partially treated or untreated may be more liable to rupture or bleed than not infected patients.

Brain Immune Interactions-Novel Emerging Options to Treat Acute Ischemic Brain Injury

Ischemic stroke is still among the leading causes of mortality and morbidity worldwide. Despite intensive advancements in medical sciences, the clinical options to treat ischemic stroke are limited to thrombectomy and thrombolysis using tissue plasminogen activator within a narrow time window after stroke. Current state of the art knowledge reveals the critical role of local and systemic inflammation after stroke that can be triggered by interactions taking place at the brain and immune system interface. Here, we discuss different cellular and molecular mechanisms through which brain–immune interactions can take place. Moreover, we discuss the evidence how the brain influence immune system through the release of brain derived antigens, damage-associated molecular patterns (DAMPs), cytokines, chemokines, upregulated adhesion molecules, through infiltration, activation and polarization of immune cells in the CNS. Furthermore, the emerging concept of stemness-induced cellular immunity in the context of neurodevelopment and brain disease, focusing on ischemic implications, is discussed. Finally, we discuss current evidence on brain–immune system interaction through the autonomic nervous system after ischemic stroke. All of these mechanisms represent potential pharmacological targets and promising future research directions for clinically relevant discoveries.

Stroke Associated with SARS-CoV-2 Infection and its Pathogenesis: A Systematic Review

INTRODUCTION

The change of stroke incidence during the COVID-19 pandemic period and the proposed mechanisms of the relationship between SARS-CoV-2 and stroke is reviewed.

METHODS

Web of Science, PMC/Medline, and Scopus databases were searched until July 2020 without time and language limitations. After quality assessment, 22 articles were included in this study.

RESULTS

Based on the results, it is impossible to conclude any definite relationship between the rising or decreasing stroke frequency or the shift in the ischemic and hemorrhagic ratio and SARS-CoV-2 infection. However, it appears that SARS-CoV-2 infection has some correlation with stroke. The supposed mechanisms for the SARS-CoV-2-related hemorrhagic stroke include 1) SARS-CoV-2-related vasculopathy with the endothelial damage of small vessels, 2) viral infection-induced platelet dysfunction or thrombocytopenia, and 3) activation of the proinflammatory cascade leading to coagulopathy. The helpful strategies are receiving therapeutic anticoagulation for high D-dimer or a known thrombus due to SARS-CoV-2 infection, as well as using extracorporeal membrane oxygenation (ECMO) in some patients. Furthermore, the possible mechanisms for the SARS-CoV-2-related ischemic stroke include 1) dysregulation of angiotensin-converting enzyme 2 (a key host cellular receptor for SARSCoV-2)-related physiologic functions, 2) endothelial cell damages, 3) thrombo-inflammation, and 4) coagulopathy and coagulation abnormalities related to SARS-CoV-2 infection.

CONCLUSION

A better understanding of the SARS-CoV-2 pathogenesis and its relation to neurologic abnormalities such as stroke can help to design new therapeutic approaches.

COVID-19 Infection and Circulating Microparticles-Reviewing Evidence as Microthrombogenic Risk Factor for Cerebral Small Vessel Disease

Severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) due to novel coronavirus disease 2019 (COVID-19) has affected the global society in numerous unprecedented ways, with considerable morbidity and mortality. Both direct and indirect consequences from COVID-19 infection are recognized to give rise to cardio- and cerebrovascular complications. Despite current limited knowledge on COVID-19 pathogenesis, inflammation, endothelial dysfunction, and coagulopathy appear to play critical roles in COVID-19-associated cerebrovascular disease (CVD). One of the major subtypes of CVD is cerebral small vessel disease (CSVD) which represents a spectrum of pathological processes of various etiologies affecting the brain microcirculation that can trigger subsequent neuroinflammation and neurodegeneration. Prevalent with aging, CSVD is a recognized risk factor for stroke, vascular dementia, and Alzheimer's disease. In the background of COVID-19 infection, the heightened cellular activations from inflammations and oxidative stress may result in elevated levels of microthrombogenic extracellular-derived circulating microparticles (MPs). Consequently, MPs could act as pro-coagulant risk factor that may serve as microthrombi for the vulnerable microcirculation in the brain leading to CSVD manifestations. This review aims to appraise the accumulating body of evidence on the plausible impact of COVID-19 infection on the formation of microthrombogenic MPs that could lead to microthrombosis in CSVD manifestations, including occult CSVD which may last well beyond the pandemic era.

Influenza Vaccination Status and Its Affecting Factors among Stroke Survivors: Findings from the Korea National Health and Nutrition Examination Survey

Few studies have examined the influenza vaccination rates among stroke survivors despite the importance of vaccines in preventing influenza- and stroke-related complications. Thus, we investigated the vaccination rates and the associated factors among stroke survivors using the representative Korea National Health and Nutrition Examination Survey 2014–2018. We measured and compared the vaccination rates of 591 stroke survivors and 17,997 non-stroke survivors. Multivariate logistic regression analyses of all stroke survivors and age subgroups (<65 and ≥65 years) were performed to identify the factors influencing vaccination. The overall vaccination rate was significantly higher in the stroke survivors (64.8%) than in the non-stroke survivors (41.1%), but it was low compared to global standards. Among stroke survivors aged <65 years, the rate was low (37.5%), but it improved in those aged ≥65 years (85.6%). Age ≥ 65 years, the eligible age for the national free vaccination program was the most prominent predictor of vaccination for all stroke survivors, while smoking was a negative predictor. No significant factors were found in the subgroup analyses according to age (<65 and ≥65 years). Therefore, implementing strategic public health policies, such as expanding the free vaccination program to stroke survivors aged <65 years, may improve vaccine coverage.

Stroke in a child with SARS-CoV-2 infection: A case report

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Some patients with COVID-19 show widely neurological manifestations including stroke. We report a child who was hospitalized due to seizures and was later diagnosed with COVID-19. Acute infarction was seen in the right putamen, globus pallidus, and the posterior part of the insula. A small focal dilatation within M1 segment of the left middle cerebral artery (MCA) was also observed. According to the present case report, COVID-19 infection may contribute to the occurrence and development of ischemic stroke.

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

The severe acute respiratory syndrome coronavirus 2 or coronavirus disease 2019 (COVID-19) pandemic has raised concerns about the correlation with this viral illness and increased risk of stroke. Although it is too early in the pandemic to know the strength of the association between COVID-19 and stroke, it is an opportune time to review the relationship between acute viral illnesses and stroke. Here, we summarize pathophysiological principles and available literature to guide understanding of how viruses may contribute to ischemic stroke. After a review of inflammatory mechanisms, we summarize relevant pathophysiological principles of vasculopathy, hypercoagulability, and hemodynamic instability. We will end by discussing mechanisms by which several well-known viruses may cause stroke in an effort to inform our understanding of the relationship between COVID-19 and stroke.

Severe acute respiratory syndrome coronavirus 2 infection reaches the human nervous system: How?

Without protective and/or therapeutic agents the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection known as coronavirus disease 2019 is quickly spreading worldwide. It has surprising transmissibility potential, since it could infect all ages, gender, and human sectors. It attacks respiratory, gastrointestinal, urinary, hepatic, and endovascular systems and can reach the peripheral nervous system (PNS) and central nervous system (CNS) through known and unknown mechanisms. The reports on the neurological manifestations and complications of the SARS-CoV-2 infection are increasing exponentially. Herein, we enumerate seven candidate routes, which the mature or immature SARS-CoV-2 components could use to reach the CNS and PNS, utilizing the within-body cross talk between organs. The majority of SARS-CoV-2-infected patients suffer from some neurological manifestations (e.g., confusion, anosmia, and ageusia). It seems that although the mature virus did not reach the CNS or PNS of the majority of patients, its unassembled components and/or the accompanying immune-mediated responses may be responsible for the observed neurological symptoms. The viral particles and/or its components have been specifically documented in endothelial cells of lung, kidney, skin, and CNS. This means that the blood-endothelial barrier may be considered as the main route for SARS-CoV-2 entry into the nervous system, with the barrier disruption being more logical than barrier permeability, as evidenced by postmortem analyses.

Does COVID-19 contribute to development of neurological disease?

BACKGROUND

Although coronavirus disease 2019 (COVID-19) has been associated primarily with pneumonia, recent data show that the causative agent of COVID-19, the coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can infect a large number of vital organs beyond the lungs, such as the heart, kidneys, and the brain. Thus, there is evidence showing possible retrograde transmission of the virus from the olfactory epithelium to regions of the brain stem.

METHODS

This is a literature review article. The research design method is an evidence-based rapid review. The present discourse aim is first to scrutinize and assess the available literature on COVID-19 repercussion on the central nervous system (CNS). Standard literature and database searches were implemented, gathered relevant material, and extracted information was then assessed.

RESULTS

The angiotensin-converting enzyme 2 (ACE2) receptors being the receptor for the virus, the threat to the central nervous system is expected. Neurons and glial cells express ACE2 receptors in the CNS, and recent studies suggest that activated glial cells contribute to neuroinflammation and the devastating effects of SARS-CoV-2 infection on the CNS. The SARS-CoV-2-induced immune-mediated demyelinating disease, cerebrovascular damage, neurodegeneration, and depression are some of the neurological complications discussed here.

CONCLUSION

This review correlates present clinical manifestations of COVID-19 patients with possible neurological consequences in the future, thus preparing healthcare providers for possible future consequences of COVID-19.

Therapeutic efficacy of α7 ligands after acute ischaemic stroke is linked to conductive states of α7 nicotinic ACh receptors

BACKGROUND AND PURPOSE

Targeting α7 nicotinic ACh receptors (nAChRs) in neuroinflammatory disorders including acute ischaemic stroke holds significant therapeutic promise. However, therapeutically relevant signalling mechanisms remain unidentified. Activation of neuronal α7 nAChRs triggers ionotropic signalling, but there is limited evidence for it in immunoglial tissues. The α7 ligands which are effective in reducing acute ischaemic stroke damage promote α7 ionotropic activity, suggesting a link between their therapeutic effects for treating acute ischaemic stroke and activation of α7 conductive states.

EXPERIMENTAL APPROACH

This hypothesis was tested using a transient middle cerebral artery occlusion (MCAO) model of acute ischaemic stroke, NS6740, a known selective non-ionotropic agonist of α7 nAChRs and 4OH-GTS-21, a partial α7 agonist. NS6740-like ligands exhibiting low efficacy/potency for ionotropic activity will be referred to as non-ionotropic agonists or "metagonists".

KEY RESULTS

4OH-GTS-21, used as a positive control, significantly reduced neurological deficits and brain injury after MCAO as compared to vehicle and NS6740. By contrast, NS6740 was ineffective in identical assays and reversed the effects of 4OH-GTS-21 when these compounds were co-applied. Electrophysiological recordings from acute hippocampal slices obtained from NS6740-injected animals demonstrated its remarkable brain availability and protracted effects on α7 nAChRs as evidenced by sustained (>8 h) alterations in α7 ionotropic responsiveness.

CONCLUSION AND IMPLICATIONS

These results suggest that α7 ionotropic activity may be obligatory for therapeutic efficacy of α7 ligands after acute ischaemic stroke yet, highlight the potential for selective application of α7 ligands to disease states based on their mode of receptor activation.

The impact of coronavirus 2019 (COVID-19) on neurosurgical practice and training: a review article

The 2019 coronavirus pandemic (COVID-19) has affected all of society at different levels. Similarly, COVID-19 has significantly impacted every medical field, including neurosurgery. By exposing scarcities in the healthcare industry and requiring the reallocation of available resources towards the priority setting and away from elective surgeries and outpatient visits, the pandemic posed new, unprecedented challenges to the medical community. Despite the redistribution of resources towards COVID-19 patients and away from elective surgeries, urgent and emergent surgeries for life-threatening conditions needed to be continued. The neurosurgical community, like other specialties not directly involved in the care of COVID-19 patients, initially struggled to balance the needs of COVID-19 patients with those of neurosurgical patients, residents, and researchers. Several articles describing the effect of COVID-19 on neurosurgical practice and training have been published throughout the COVID-19 pandemic. This article aims to provide a focused review of the impact COVID-19 has had on neurosurgical practice and training as well as describe neurological manifestations of the disease.

Coronavirus disease 2019 (COVID-19) can predispose young to Intracerebral hemorrhage: a retrospective observational study

Background

The respiratory system involvement is the most common presentation of Coronavirus disease 2019 (COVID-19). However, other organs including the central nervous system (CNS) could be affected by the virus. Strokes, seizures, change in mental status, and encephalitis have been reported as the neurological manifestation of the disease. We hypothesized that COVID-19 could predispose younger patients to spontaneous intracerebral hemorrhage (ICH). The present study aimed to investigate whether COVID-19 has any relationship with the occurrence of spontaneous ICH in young or not.

Methods

We retrospectively evaluated all the patients with spontaneous ICH who were referred to our center between 20 Feb and 1 Sep 2020. The demographic, clinical, radiological, and laboratory test data were evaluated. Patients were divided into two groups. The COVID-19 positive patients and COVID-19 negative ones. All the variables including age, sex, history of hypertension, diabetes mellitus, smoking, Glasgow Coma Scale (GCS), hematoma volume and location, the presence of intraventricular hemorrhage and hydrocephalus on admission, the length of hospital stay, the lab test results and the clinical outcome at last visit or discharge as Glasgow Outcome Scale (GOS) were compared between the two groups.

Results

There were 22 COVID-19 positive patients (20.8%) and 84 COVID-19 negative ones (79.2%). The mean age of the patients in the case group (54.27 ± 4.67) was significantly lower than that in the control group (69.88 ± 4.47) (p < 0.05). Meanwhile, our results showed a significant difference between the two groups based on the presence of chronic arterial hypertension (p < 0.05). There were no significant differences between the two groups based on gender, diabetes mellitus, smoking, Glasgow Coma Scale (GCS), hematoma volume, need for surgery, the presence of intraventricular hemorrhage and hydrocephalus on admission, White Blood Cell (WBC) count, platelet count, Prothrombin Time (PT), and Partial Thromboplastin Time (PTT) (p > 0.05).

Conclusions

Our results show that COVID positive patients with ICH are younger and with less predisposing factors than COVID negative subjects with ICH.

Neuroimaging Findings in Conjunction with Severe COVID-19

PURPOSE

COVID-19 has a variable, but well-described course. However, some patients additionally present with neurological symptoms. Recent studies also show a broad range of neuroimaging features. The purpose of this study was to perform a snapshot analysis to approximate the frequency and types of neuroimaging findings on CT and MRI scans in a large cohort of SARS-CoV-2-positive patients in a level I COVID-19 center, both in general and in critically ill patients.

MATERIALS AND METHODS

We retrospectively analyzed brain CT and MRI scans of 34 hospitalized COVID-19 patients at our level I COVID-19 center between March 15 and April 24 with regard to pathological neuroimaging findings. In addition, clinical parameters such as neurological symptoms, comorbidities, and type of ventilation therapy were also documented. A descriptive statistical analysis was performed.

RESULTS

Pathological findings were detected in 38.2 % of patients in the study cohort. Based on the weekly institutional SARS-CoV-2 report of all positively tested patients in our clinic at the time of data collection, neuroimaging findings could be found in 6 % of all patients (34/565). The most common findings were microbleeds (20.6 %) and signs of hypoxic brain injury (11.8 %). Furthermore, cortical subarachnoid hemorrhage, typical and atypical cerebral hematomas, ischemic strokes, and generalized brain edema were documented. All neuroimaging findings occurred in patients who were either intubated or treated by ECMO.

CONCLUSION

Based on the analysis of this large cohort of SARS-CoV-2-positive patients, pathological neuroimaging findings seem to be relatively rare in general but do occur in a substantial proportion of patients with severe COVID-19 disease needing intubation or ECMO.

KEY POINTS

· Neuroimaging findings appear to be relatively rare in SARS-CoV-2 positive patients.. · Pathological findings occur mainly in critically ill COVID-19 patients.. · Frequent findings include hemorrhagic, ischemic and hypoxic changes.. · Critically ill COVID-19 patients should receive neuroimaging with a low threshold..

CITATION FORMAT

· Büttner L, Bauknecht HC, Fleckenstein FN et al. Neuroimaging Findings in Conjunction with Severe COVID-19. Fortschr Röntgenstr 2021; 193: 822 - 829.

Neurological manifestations of coronavirus infections: role of angiotensin-converting enzyme 2 in COVID-19

AIM OF THE STUDY

In December 2019, a highly pathogenic coronavirus called SARS-CoV-2 (formerly identified as 2019-nCoV) appeared in Wuhan, China, and has since been spreading rapidly around the world. we reviewed the neurological manifestations of this infection and the potential of ACE2 in the nervous system.

MATERIALS AND METHODS

Six databases (Medline, Scopus, Embase, Web of Science, WHO, and google scholar) were searched and screened by the authors for having appropriate information about covid-19. Finally, 72 studies were identified, summarized and reviewed.

RESULT

The most specific manifestation of SARS-CoV-2 patients is pulmonary distress, and several patients admitted to intensive care units were not able to breathe spontaneously. In addition, the SARS-CoV-2 outbreak has a significant effect on nervous systems and may even lead to serious neurological damage. The neuroinvasive pathobiology is still not fully elucidated and thus the effect of CoV infections on the nervous system needs to be explored. The spike protein of the virus and the angiotensin-converting enzyme 2 (ACE2) lead to the presence of both SARS-CoV and SARS-CoV-2 in the cells and, subsequently, decreased ACE2 expression.

CONCLUSION

The therapeutic possibilities of ACE2 antibody, ACE2-derived peptides, and small molecule blockers of ACE2 include a receptor-binding domain blocking approach. Hence, future studies of ACE2 may be very helpful in discovering a therapy for SARS-CoV-2.

2019 novel coronavirus disease with secondary ischemic stroke: two case reports

BACKGROUND

The COVID-19 pandemic, which broke out in Wuhan in 2019, has become the global health crisis of our time. Elderly patients with certain fundamental diseases are more likely to develop severe cases. The secondary lesion following viral infection have only rarely been reported.

CASE PRESENTATION

We here report two cases of coronavirus-infected pneumonia with acute ischemic stroke in middle-aged patients. In both COVID-19 cases, neurological physical examinations showed normal results before infection. Lymphocytopenia, accompanied by elevated cytokines and D-dimers, were found from serum clinical laboratory examination at admission. Dysarthria and limb muscle weakness are initial manifestations, occurring one week after infect-causative pathogen, SARS-CoV-2. The head CT and head/neck arterial CTA showed small-vessel occlusion. The patients were diagnosed with coronavirus diseases with secondary acute ischemic stroke. They were treated with tirofiban and followed up with daily aspirin and atorvastatin.

CONCLUSIONS

These cases suggested that secondary ischemic stroke, mainly manifested as small-vessel occlusion, should be considered for COVID-19 patients and diagnosed and treated promptly.

Crosstalk Between Covid-19 and Associated Neurological Disorders: A Review

COVID-19 is a global pandemic, primarily affecting the pulmonary system but its effects on other systems are not certain. Coronavirus, the causative organism, binds with angiotensinconverting enzyme 2 (ACE2) receptors in the lungs and produces pneumonia-like symptoms. Other than lungs, ACE2 receptors are also seen in the endothelium of blood vessels. Therefore, viruses can bind to the ACE2 that is present in the endothelium of brain blood vessels and thus can invade BBB, leading to neuronal damage. It is also believed that olfactory cells rich in ACE2 receptors may act as the main route of viral spread into various parts of the brain. The reported neurological effects of SARS-CoV-2 include cerebrovascular diseases, ageusia and anosmia, Guillain Barre Syndrome, and viral encephalitis. The extent of neurological involvement in SARS-CoV-2 infection warrants the necessity of further research to systematically classify neurological complications associated with SARS-CoV-2 infection, its diagnosis, and treatment. As ACE2 receptors are present in various other organs, it is obligatory to study the effect of coronavirus on other organs also. Since the long-lasting effects of the COVID-19 are unclear, more studies should be conducted to confirm the effect of the virus on the central nervous system. This review highlights the reported neurological manifestations of SARS-CoV-2 and its mechanism.

Acute Cerebrovascular Events With COVID-19 Infection

BACKGROUND AND PURPOSE

Coronavirus disease 2019 (COVID-19) has been associated with an increased incidence of thrombotic events, including stroke. However, characteristics and outcomes of COVID-19 patients with stroke are not well known.

METHODS

We conducted a retrospective observational study of risk factors, stroke characteristics, and short-term outcomes in a large health system in New York City. We included consecutively admitted patients with acute cerebrovascular events from March 1, 2020 through April 30, 2020. Data were stratified by COVID-19 status, and demographic variables, medical comorbidities, stroke characteristics, imaging results, and in-hospital outcomes were examined. Among COVID-19-positive patients, we also summarized laboratory test results.

RESULTS

Of 277 patients with stroke, 105 (38.0%) were COVID-19-positive. Compared with COVID-19-negative patients, COVID-19-positive patients were more likely to have a cryptogenic (51.8% versus 22.3%, P<0.0001) stroke cause and were more likely to suffer ischemic stroke in the temporal (P=0.02), parietal (P=0.002), occipital (P=0.002), and cerebellar (P=0.028) regions. In COVID-19-positive patients, mean coagulation markers were slightly elevated (prothrombin time 15.4±3.6 seconds, partial thromboplastin time 38.6±24.5 seconds, and international normalized ratio 1.4±1.3). Outcomes were worse among COVID-19-positive patients, including longer length of stay (P<0.0001), greater percentage requiring intensive care unit care (P=0.017), and greater rate of neurological worsening during admission (P<0.0001); additionally, more COVID-19-positive patients suffered in-hospital death (33% versus 12.9%, P<0.0001).

CONCLUSIONS

Baseline characteristics in patients with stroke were similar comparing those with and without COVID-19. However, COVID-19-positive patients were more likely to experience stroke in a lobar location, more commonly had a cryptogenic cause, and had worse outcomes.

Applications of Non-invasive Neuromodulation for the Management of Disorders Related to COVID-19

Background: Novel coronavirus disease (COVID-19) morbidity is not restricted to the respiratory system, but also affects the nervous system. Non-invasive neuromodulation may be useful in the treatment of the disorders associated with COVID-19. Objective: To describe the rationale and empirical basis of the use of non-invasive neuromodulation in the management of patients with COVID-10 and related disorders. Methods: We summarize COVID-19 pathophysiology with emphasis of direct neuroinvasiveness, neuroimmune response and inflammation, autonomic balance and neurological, musculoskeletal and neuropsychiatric sequela. This supports the development of a framework for advancing applications of non-invasive neuromodulation in the management COVID-19 and related disorders. Results: Non-invasive neuromodulation may manage disorders associated with COVID-19 through four pathways: (1) Direct infection mitigation through the stimulation of regions involved in the regulation of systemic anti-inflammatory responses and/or autonomic responses and prevention of neuroinflammation and recovery of respiration; (2) Amelioration of COVID-19 symptoms of musculoskeletal pain and systemic fatigue; (3) Augmenting cognitive and physical rehabilitation following critical illness; and (4) Treating outbreak-related mental distress including neurological and psychiatric disorders exacerbated by surrounding psychosocial stressors related to COVID-19. The selection of the appropriate techniques will depend on the identified target treatment pathway. Conclusion: COVID-19 infection results in a myriad of acute and chronic symptoms, both directly associated with respiratory distress (e.g., rehabilitation) or of yet-to-be-determined etiology (e.g., fatigue). Non-invasive neuromodulation is a toolbox of techniques that based on targeted pathways and empirical evidence (largely in non-COVID-19 patients) can be investigated in the management of patients with COVID-19.

Coexistencia de hemorragia subaracnoidea aneurismática accidentada y tromboembolia pulmonar en paciente con COVID-19. Reporte de un caso

El COVID-19 es causado por el SARS-CoV2, un coronavirus beta, que actualmente es responsable de una pandemia con alta tasa de contagiosidad y mortalidad a nivel mundial. Este virus, a más de su impacto a nivel pulmonar, puede desencadenar una tormenta de citocinas proinflamatorias que dañan el endotelio vascular generando endotelitis, disfunción endotelial y alta prevalencia de eventos trombóticos. Clínica y analíticamente la expresión de este fenómeno se evidencia con niveles elevados de dímero D, trombosis venosa y/o arterial, embolia pulmonar, enfermedades cerebrovasculares y cardiovasculares y trombosis microvascular difusa. Dado que el endotelio es un órgano vital en la regulación del tono vascular y la homeostasis, su afectación conduce a vasoconstricción, isquemia, infarto e inflamación y esto posiblemente cause debilitamiento de su estructura. En él siguiente reporte de caso, narramos la historia de un paciente con neumonía por SARS-CoV2, que presentó concomitancia de alteraciones endoteliales hemorrágicas y trombóticas, expresadas por una hemorragia subaracnoidea aneurismática accidentada y una tromboembolia pulmonar submasiva.

Spleen is not required for therapeutic effects of 4OH-GTS-21, a selective α7 nAChR agonist, in the sub-acute phase of ischemic stroke in rats

Acute ischemic stroke (AIS) causes both central and peripheral inflammation, while activation of α7 nicotinic acetylcholine receptors (nAChRs) provides both central and peripheral anti-inflammatory and anti-apoptotic effects. Here, we provide evidence that 4OH-GTS-21, a selective α7 agonist, produces its therapeutic effects via primarily central sites of action because 4OH-GTS-21 was found equally effective in splenectomized and non-spenectomized rats in the sub-acute phase of ischemic stroke (≤1 week). However, the spleen may boost the therapeutic efficacy of 4OH-GTS-21 in certain behavioral tasks as our data also indicated. In our tests, AIS was modeled by transient middle cerebral artery occlusion (tMCAO). Splenectomy was done 2 weeks before tMCAO. We determined that: 1) Daily 4OH-GTS-21 treatments for 7 days after tMCAO significantly reduced neurological deficits and brain injury in both splenectomized and non-spelenectomized rats demonstrating that the spleen is not required for therapeutic benefits of 4OH-GTS-21; 2) The effects of 4OH-GTS-21 in the adhesive sticker removal test were significantly weaker in splenectomized animals suggesting that the spleen boosts the efficacy of 4OH-GTS-21 in the first week after tMCAO; and 3) Ischemic brain injury was not significantly affected by splenectomy in both vehicle-treated and 4OH-GTS-21-treated animals. These data support the hypothesis that the therapeutic efficacy of sub-chronic (≤1 week) 4OH-GTS-21 primarily originates from central sites of action. These results validate brain availability as a critical factor for developing novel α7 ligands for AIS.

Ruptured cerebral pseudoaneurysm in an adolescent as an early onset of COVID-19 infection: case report

The clinical manifestations of coronavirus disease 2019 (COVID-19) are non-specific and multi-inflammatory. They vary from mild to severe manifestations that can be life-threatening. The association of SARS-CoV-2 infection and pseudoaneurysm formation or rupture of an already existing aneurysm is still unexplored. Several mechanisms may be involved, including the direct destruction to the artery by the viral infection or through the release of the inflammatory cytokines. We are presenting a case of a 13-year-old girl with a ruptured cerebral pseudoaneurysm of the left middle cerebral artery (M2 segment) with severe intracerebral hemorrhage as the earliest manifestation of COVID-19 infection.

Headache in Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Infection: A Narrative Review

OBJECTIVE

To summarize available literature regarding headache as a manifestation of coronaviruses and to describe potential underlying mechanisms.

REVIEW METHODS

References for this review were identified by searches within PubMed without any date restrictions. The search terms used were coronavirus disease 2019 (COVID-19) clinical manifestation, COVID-19 epidemiology, neurologic findings in COVID-19, headache in COVID-19, neurologic manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and headache in SARS-CoV-2.

RESULTS

Headache is one of the most common neurologic complaints in patients with SARS-CoV-2. While the pathophysiological connection between headache and SARS-CoV-2 is unclear, inflammatory mechanisms may play a key role. One of the mechanisms cited in the literature of migraine and other headache disorders is the activation of nociceptive sensory neurons by cytokines and chemokines. A similar mechanism has been reported in SARS-CoV-2 with the release of cytokines and chemokines by macrophages throughout the course of infection. Other mechanisms for headache in SARS-CoV-2 include (1) viral neuroinvasion as seen with viral encephalitis; (2) hypoxemia due to the well-described pulmonary manifestations of the disease; and (3) thrombosis secondary to COVID-19 induced hypercoagulable states.

CONCLUSION

According to the Centers for Disease Control, common symptoms of human coronavirus include fever, cough, runny nose, sore throat, and headache. In the case of SARS-CoV-2, there are limited reports about headaches, one of the most common clinical manifestations. There are currently no studies that focus specifically on headache among patients with SARS-CoV-2 infection.

Neurological Damage by Coronaviruses: A Catastrophe in the Queue!

Neurological disorders caused by neuroviral infections are an obvious pathogenic manifestation. However, non-neurotropic viruses or peripheral viral infections pose a considerable challenge as their neuropathological manifestations do not emerge because of primary infection. Their secondary or bystander pathologies develop much later, like a syndrome, during and after the recovery of patients from the primary disease. Massive inflammation caused by peripheral viral infections can trigger multiple neurological anomalies. These neurological damages may range from a general cognitive and motor dysfunction up to a wide spectrum of CNS anomalies, such as Acute Necrotizing Hemorrhagic Encephalopathy, Guillain-Barré syndrome, Encephalitis, Meningitis, anxiety, and other audio-visual disabilities. Peripheral viruses like Measles virus, Enteroviruses, Influenza viruses (HIN1 series), SARS-CoV-1, MERS-CoV, and, recently, SARS-CoV-2 are reported to cause various neurological manifestations in patients and are proven to be neuropathogenic even in cellular and animal model systems. This review presents a comprehensive picture of CNS susceptibilities toward these peripheral viral infections and explains some common underlying themes of their neuropathology in the human brain.

Coronavirus Disease-2019 Conundrum: RAS Blockade and Geriatric-Associated Neuropsychiatric Disorders

Coronavirus Disease 2019 (COVID-19) is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which primarily targets the human respiratory system and may lead to severe pneumonia and ultimately death. Mortality rate is particurlarly high among people beyond the sixth decade of life with cardiovascular and metabolic diseases. The discovery that the SARS-CoV-2 uses the renin-angiotensin system (RAS) component ACE2 as a receptor to invade host epithelial cells and cause organs damage resulted in a debate regarding the role of ACE inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) therapies during COVID-19 pandemic. Some authors proposed the discontinuation of ACEIs and ARBs for cardiovascular, kidney, and metabolic diseases, while expert opinions have discouraged that due to limited empirical evidence of their negative effect on COVID-19 outcomes, and that withdrawing treatment may contribute to clinical decompensation in high-risk patients. Moreover, as cardiovascular and metabolic diseases are associated with neurodegenerative and psychiatric disorders, especially among older adults, a critical appraisal of the potential positive effects of ACEIs and ARBs is highly needed. Herein, we aim to discuss the conundrum of ACEIs and ARBs use in high-risk patients for COVID-19, and their potential protective role on the development and/or progression of geriatric neuropsychiatric disorders.

COVID-19 and the central nervous system

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Awareness of atypical clinical presentation of COVID patients.

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Continued sharing and publishing of case series to better understand symptoms, signs, and prognosis of patients with COVID.

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Continued studies needed to fully undertstand the long term consequences of COVID on the neurological system.

Neuroinvasion, neurotropic, and neuroinflammatory events of SARS-CoV-2: understanding the neurological manifestations in COVID-19 patients

Respiratory viruses are opportunistic pathogens that infect the upper respiratory tract in humans and cause severe illnesses, especially in vulnerable populations. Some viruses have neuroinvasive properties and activate the immune response in the brain. These immune events may be neuroprotective or they may cause long-term damage similar to what is seen in some neurodegenerative diseases. The new “Severe Acute Respiratory Syndrome Coronavirus 2” (SARS-CoV-2) is one of the Respiratory viruses causing highly acute lethal pneumonia coronavirus disease 2019 (COVID-19) with clinical similarities to those reported in “Severe Acute Respiratory Syndrome Coronavirus”(SARS-CoV) and the “Middle East Respiratory Syndrome Coronavirus”(MERS-CoV) including neurological manifestation. To examine the possible neurological damage induced by SARS-CoV-2, it is necessary to understand the immune reactions to viral infection in the brain, and their short- and long-term consequences. Considering the similarities between SARS-CoV and SARS-CoV-2, which will be discussed, cooperative homological and phylogenetical studies lead us to question if SARS-CoV-2 can have similar neuroinvasive capacities and neuroinflammatiory events that may lead to the same short- and long-term neuropathologies that SARS-CoV had shown in human and animal models. To explain the neurological manifestation caused by SARS-CoV-2, we will present a literature review of 765 COVID-19 patients, in which 18% had neurological symptoms and complications, including encephalopathy, encephalitis and cerebrovascular pathologies, acute myelitis, and Guillain-Barré syndrome. Clinical studies describe anosmia or partial loss of the sense of smell as the most frequent symptom in COVID19 patients, suggesting that olfactory dysfunction and the initial ultrarapid immune responses could be a prognostic factor.

Obesity, Cardiovascular Disease, and Influenza: How Are They Connected?

Purpose of Review

To better understand the impact of obesity and cardiovascular diseases on influenza A infection.

Recent Findings

This infection could have detrimental outcomes in obese patients with cardiovascular diseases, such as an increased risk, length of hospitalization, disease severity, morbidity, and mortality. Nevertheless, there also might be some cardioprotective benefits associated with influenza vaccination, such as a reduced mortality, hospitalization, and acute coronary syndromes, in patients with coronary heart disease and/or heart failure.

Summary

Obesity negatively impacts immune function and host defense. Recent studies report obesity to be an independent risk factor for increased morbidity and mortality following infection. Obese patients might need special considerations in the treatment; however, there is not enough evidence to fully comprehend the mechanisms behind the reduced immunocompetence when influenza A infection occurs. Future studies should focus on special consideration treatments when the patients have not been vaccinated and have cardiovascular diseases.

Nervous system involvement after infection with COVID-19 and other coronaviruses

Viral infections have detrimental impacts on neurological functions, and even to cause severe neurological damage. Very recently, coronaviruses (CoV), especially severe acute respiratory syndrome CoV 2 (SARS-CoV-2), exhibit neurotropic properties and may also cause neurological diseases. It is reported that CoV can be found in the brain or cerebrospinal fluid. The pathobiology of these neuroinvasive viruses is still incompletely known, and it is therefore important to explore the impact of CoV infections on the nervous system. Here, we review the research into neurological complications in CoV infections and the possible mechanisms of damage to the nervous system.

Impact of Infection on the Risk of Recurrent Stroke Among Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Infection occurs commonly in patients with acute ischemic stroke. We aimed to investigate the association of infection with short- and long-term risk of recurrent stroke in patients with ischemic stroke.

METHODS

Data were derived from ischemic stroke patients in 2 stroke registries: the CSCA (Chinese Stroke Center Alliance) program recorded medical data during hospitalization, and the CNSR-III (Third China National Stroke Registry) recorded the medical data during hospitalization and finished 1-year follow-up. Associations of infection (pneumonia or urinary tract infection) during hospitalization with recurrent stroke in short (during hospitalization) and long term (since 30 days to 1 year after stroke onset) were analyzed. Short-term outcomes were analyzed with logistic models and long-term outcomes with Cox models.

RESULTS

In the CSCA (n=789 596), the incidence of infection during hospitalization reached 9.6%. Patients with infection had a higher risk of stroke recurrence during hospitalization compared with patients without infection (10.4% versus 5.2%; adjusted odds ratio, 1.70 [95% CI, 1.65-1.75]; P<0.0001). In the CNSR-III (n=13 549), the incidence of infection during hospitalization was 6.5%. Infection during hospitalization was significantly associated with short-term risk of recurrent stroke (7.4% versus 3.9%; adjusted odds ratio, 1.40 [95% CI, 1.05-1.86]; P=0.02) but not with long-term risk of recurrent stroke (7.2% versus 5.2%; adjusted hazard ratio, 1.16 [95% CI, 0.88-1.52]; P=0.30).

CONCLUSIONS

Infection was an independent risk factor for high risk of early stroke recurrence during hospitalization, but we have not found its sustained effect on long-term recurrent risk in patients with acute ischemic stroke.

COVID-19 Is an Independent Risk Factor for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Coronavirus disease 2019 (COVID-19) is an active worldwide pandemic with diverse complications. Stroke as a presentation has not been strongly associated with COVID-19. The authors aimed to retrospectively review a link between COVID-19 and acute stroke.

MATERIALS AND METHODS

We conducted a retrospective case-control study of 41 cases and 82 control subjects matched by age, sex, and risk factors. Cases were patients who underwent stroke alert imaging with confirmed acute stroke on imaging between March 16 and April 5, 2020, at 6 hospitals across New York City. Control subjects were those who underwent stroke alertimaging during the same timeframe without imaging evidence of acute infarction. Data pertaining to diagnosis of COVID-19 infection, patient demographics, and risk factors were collected. A univariate analysis was performed to assess the covariate effect of risk factors and COVID-19 status on stroke imaging with positive findings.

RESULTS

The mean age for cases and controls was 65.5 ± 15.3 years and 68.8 ± 13.2 years, respectively. Of patients with acute ischemic stroke, 46.3% had COVID-19 infection compared with 18.3% of controls (P = .001). After adjusting for age, sex, and risk factors, COVID-19 infection had a significant independent association with acute ischemic stroke compared with control subjects (OR, 3.9; 95% CI, 1.7-8.9; P = .001).

CONCLUSIONS

We demonstrated that COVID-19 infection is significantly associated with imaging confirmation of acute ischemic stroke, and patients with COVID-19 should undergo more aggressive monitoring for stroke.

Intracerebral Hemorrhage and SARS-CoV-2: Association or Causation

Background:

Recent respiratory infection including SARS-CoV-2 is an independent risk factor for acute cerebrovascular disease.

Purpose:

There have been reports linking haemorrhagic strokes to SARS-CoV-2 infection during this pandemic, which lead us to evaluate if SARS-CoV-2 infection could be associated with increased risk of intracerebral haemorrhage (ICH).

Methods:

A retrospective observational study evaluating all stroke cases admitted in our centre in the past one month.

Results:

More than half (56%) had ICH, compared to 22% last year. Two patients with ICH were SARS-CoV-2 positive and they had no or mild respiratory symptoms and had higher occurrence of renal dysfunction.

Conclusion:

There could be possible association between ICH and SARS-CoV-2 infections. However, a prospective study with larger sample size is needed to elucidate the pathogenesis.

Elevated level of cerebrospinal fluid and systemic chemokine CCL5 is a predictive biomarker of clinical outcome after aneurysmal subarachnoid hemorrhage (aSAH)

BACKGROUND

Pathophysiology of aneurysmal subarachnoid hemorrhage (aSAH) is highly complex. Bleeding from ruptured aneurysm causes increase in intracranial pressure that disrupts blood-brain barrier leading to infiltration of peripheral immune cells. Interactions between the infiltrated leukocytes and the resident brain cells in the injured tissue mainly determine the delayed tissue damage. Recruitment of leukocytes in the injured brain is mainly mediated by the chemokines. Chemokine C-C motif ligand 5 (CCL5) is a potent pro-inflammatory chemokine shown to be upregulated in preclinical SAH studies. However, detailed clinical investigations exploring the association of cerebrospinal fluid (CSF) and systemic CCL5 and post-aSAH complications and clinical outcome are still lacking. This study investigated CSF and systemic CCL5 after aSAH and its association with clinical outcome and post-aSAH complications.

METHODS

CSF and serum from control and aSAH patients were obtained after centrifugation of the CSF and peripheral blood, and were preserved at -80 °C until quantification by an enzyme-linked immunoassay. Patient pertinent data, post-aSAH complications and clinical outcome (modified Rankin scale [mRS] and Glasgow outcome scale [GOS]) were retrieved from patient records.

RESULTS

A significant increase in CSF and serum CCL5 levels was observed on post-aSAH day 1 and day 7 compared to control patients. Dichotomization of patients to poor (mRS 3-6 or GOS 1-3) and good (mRS 0-2 or GOS 4-5) clinical outcomes showed significantly higher serum CCL5 levels in patients with good clinical outcome at discharge, but lower CSF CCL5 levels. Interestingly, significantly lower serum CCL5 levels were observed on post-aSAH day 7 in patients who have additional intracerebral bleeding or the patients who developed chronic hydrocephalus or pneumonia. Whereas, CSF CCL5 levels significantly increased on post-aSAH day 1 in patients developing chronic hydrocephalus, delayed ischemic neurological deficits and intraventricular hemorrhage. CSF CCL5 levels on post-aSAH day 1 were correlated with poor clinical outcome, however, serum CCL5 levels on post-aSAH day 7 were correlated with good clinical outcome.

CONCLUSION

Systemic and CSF CCL5 levels were elevated after aSAH and levels of serum CCL5 on day 7 were associated independently with clinical outcome (GOS and mRS) at discharge. Therapeutic approaches targeting CCL5 might be beneficial in aSAH.

Cerebrovascular and Neurological Dysfunction under the Threat of COVID-19: Is There a Comorbid Role for Smoking and Vaping?

The recently discovered novel coronavirus, SARS-CoV-2 (COVID-19 virus), has brought the whole world to standstill with critical challenges, affecting both health and economic sectors worldwide. Although initially, this pandemic was associated with causing severe pulmonary and respiratory disorders, recent case studies reported the association of cerebrovascular-neurological dysfunction in COVID-19 patients, which is also life-threatening. Several SARS-CoV-2 positive case studies have been reported where there are mild or no symptoms of this virus. However, a selection of patients are suffering from large artery ischemic strokes. Although the pathophysiology of the SARS-CoV-2 virus affecting the cerebrovascular system has not been elucidated yet, researchers have identified several pathogenic mechanisms, including a role for the ACE2 receptor. Therefore, it is extremely crucial to identify the risk factors related to the progression and adverse outcome of cerebrovascular-neurological dysfunction in COVID-19 patients. Since many articles have reported the effect of smoking (tobacco and cannabis) and vaping in cerebrovascular and neurological systems, and considering that smokers are more prone to viral and bacterial infection compared to non-smokers, it is high time to explore the probable correlation of smoking in COVID-19 patients. Herein, we have reviewed the possible role of smoking and vaping on cerebrovascular and neurological dysfunction in COVID-19 patients, along with potential pathogenic mechanisms associated with it.