Respiratory failure alone does not suggest central nervous system invasion by SARS-CoV-2

Potential neurological manifestations of COVID-19: a narrative review

Neurological manifestations are increasingly reported in a subset of COVID-19 patients. Previous infections related to coronaviruses, namely Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS) also appeared to have neurological effects on some patients. The viruses associated with COVID-19 like that of SARS enters the body via the ACE-2 receptors in the central nervous system, which causes the body to balance an immune response against potential damage to nonrenewable cells. A few rare cases of neurological sequelae of SARS and MERS have been reported. A growing body of evidence is accumulating that COVID-19, particularly in severe cases, may have neurological consequences although respiratory symptoms nearly always develop prior to neurological ones. Patients with preexisting neurological conditions may be at elevated risk for COVID-19-associated neurological symptoms. Neurological reports in COVID-19 patients have described encephalopathy, Guillain-Barré syndrome, myopathy, neuromuscular disorders, encephalitis, cephalgia, delirium, critical illness polyneuropathy, and others. Treating neurological symptoms can pose clinical challenges as drugs that suppress immune response may be contraindicated in COVID-19 patients. It is possible that in some COVID-19 patients, neurological symptoms are being overlooked or misinterpreted. To date, neurological manifestations of COVID-19 have been described largely within the disease trajectory and the long-term effects of such manifestations remain unknown.

Post-Coronavirus Disease 2019 Triggers the Appearance of Mixed Polyneuropathy and Brain Fog: A Case Report

Coronavirus disease 2019 (COVID-19) can directly or indirectly affect the central and peripheral nervous systems, resulting in cognitive impairment, memory problems, and a wide range of neuromuscular involvement, including neuropathies. However, the long-term neurological complications of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are not clear. The aim this study was to analyze a case report the presence of neurological sequelae due to post-Coronavirus disease 19 in a patient without apparent previous neurological symptoms. Clinical case: A 46-year-old patient, with no relevant history for the described condition, who, after severe COVID-19 infection, started a mixed neuropathy and mental fog syndrome as the main sequel. Multiple laboratory and imaging studies were performed during and after his hospital stay, and it was corroborated by an electromyography that it occurred from a neuropathy triggered by COVID-19 infection. Conclusions: This case provides additional evidence that mixed neuropathy and brain fog syndrome are potential complications of post-coronavirus disease 2019 syndrome. The neurological sequelae that manifest after a COVID-19 episode can be rapidly enhanced as a consequence of another alteration in some systems of the organism. However, future studies are necessary to elucidate the incidence of these neurological complications, their pathophysiological mechanisms and their therapeutic options.

Advances in the study of nervous system infections in COVID‐19

Shortly after its outbreak, coronavirus disease 2019 (COVID‐19) has very rapidly spread to become a global epidemic. Early clinical findings mainly included typical symptoms such as fever and cough with a very high transmission rate. Recent findings have demonstrated neurological manifestations of atypical symptoms, which is associated with poor prognosis. In this paper, we describe the neurological aspects of COVID‐19 pneumonia in terms of relevant neurons, virus‐associated receptors, and olfactory and neurological clinical manifestations and offer insights on treatment.

Does the SARS-CoV-2 pandemic really increase the frequency of peripheral facial palsy?

PURPOSE

Publications about increased number of peripheral facial paralysis in the COVID-19 pandemic emerged in the literature. However, these studies comprised of an estimate rather than a broad analysis of exact numbers. In this study, we planned to investigate whether the pandemic really resulted in an increase in facial paralysis cases admitted to the hospital by evaluating the cases who applied to our hospital due to facial paralysis in the COVID-19 pandemic year and in the previous 4 years.

MATERIALS AND METHODS

Patients who applied to our hospital due to facial paralysis between March 2016-February 2017 (Group 1), between March 2017-February 2018 (Group 2), between March 2018-February 2019 (Group 3), between March 2019-February 2020 (Group 4), and between March 2020-February 2021 (Group 5) were investigated and detailed data were noted.

RESULTS

156, 164, 149, 172 and 157 patients were admitted to the hospital due to peripheral facial paralysis in Group 1, 2, 3, 4, and 5, respectively. Of these patients, 155, 164, 145, 169, and 153 were Bell's palsy, respectively. SARS-CoV-2 RT-PCR test was positive in only 2 of the 153 patients who were diagnosed in the year of the pandemic.

CONCLUSIONS

This study showed that the number of peripheral facial paralysis detected during the COVID-19 pandemic was similar to previous years. Very few number of positive SARS-CoV-2 RT-PCR test results may have been found incidentally in Bell's palsy patients. Theses stating that SARS-CoV-2 causes peripheral facial paralysis should be supported by laboratory studies and postmortem research.

HD5 and LL-37 Inhibit SARS-CoV and SARS-CoV-2 Binding to Human ACE2 by Molecular Simulation

The coronavirus (COVID-19) pandemic is still spreading all over the world. As reported, angiotensin-converting enzyme-2 (ACE2) is a receptor of SARS-CoV-2 spike protein that initializes viral entry into host cells. Previously, the human defensin 5 (HD5) has been experimentally confirmed to be functional against the SARS-CoV-2. The present study proposes a human cathelicidin known as LL37 that strongly binds to the carboxypeptidase domain of human ACE2 compared to HD5. Therefore, LL37 bears a great potential to be tested as an anti-SARS-CoVD-2 peptide. We investigated the molecular interactions formed between the LL37 and ACE2 as well as HD5 and ACE2 tailed by their thermodynamic stability. The MM-PBSA and free energy landscape analysis outcomes confirmed its possible inhibitory effect against the SARS-CoV-2. The results obtained here could help propose a promising therapeutic strategy against the havoc caused by SARS-CoV-2 infections.

Exploring the clinical association between neurological symptoms and COVID-19 pandemic outbreak: a systematic review of current literature

OBJECT

The novel severe acute respiratory syndrome (SARS)-CoV-2 outbreak has been declared a pandemic in March, 2020. An increasing body of evidence suggests that patients with the coronavirus disease (COVID-19) might have a heterogeneous spectrum of neurological symptoms METHODS: A systematic search of two databases was performed for studies published up to May 29th, 2020. PRISMA guidelines were followed.

RESULTS

We included 19 studies evaluating 12,157 patients with laboratory-confirmed COVID-19 infections. The median age of patients was 50.3 (IQR 11.9), and the rate of male patients was 50.6% (95% CI 49.2-51.6%). The most common reported comorbidities were hypertension and diabetes (31.1%, 95% CI 30-32.3% and 13.5%, 95% CI 12.3-14.8%, respectively). Headache was reported in 7.5% of patients (95% CI 6.6-8.4%), and dizziness in 6.1% (95% CI 5.1-7.1%). Hypo/anosmia, and gustatory dysfunction were reported in 46.8 and 52.3%, of patients, respectively. Symptoms related to muscular injury ranged between 15 and 30%. Three studies reported radiological confirmed acute cerebrovascular disease in 2% of patients (95% CI 1.6-2.4%).

CONCLUSIONS

These data support accumulating evidence that a significant proportion of patients with COVID-19 infection develop neurological manifestations, especially olfactory, and gustatory dysfunction. The pathophysiology of this association is under investigation and warrants additional studies, Physicians should be aware of this possible association because during the epidemic period of COVID-19, early recognition of neurologic manifestations otherwise not explained would raise the suspect of acute respiratory syndrome coronavirus 2 infection.

SARS-CoV-2: its potential neurological manifestations and plausible mechanism: a review article

Coronavirus disease (COVID-19) was first identified in late December 2019. The disease began in Wuhan, Hubei province in China and since then it has spread quickly to many countries all over the world. COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus was majorly seen to overwhelm the respiratory system with mild to severe acute respiratory syndrome considered pathognomic for the disease. However, with time a plethora of symptoms was observed in the patients infected with COVID-19 including strong evidence for neurological symptoms. Evidence suggests that the virus has both central and peripheral nervous system manifestations. Patients, particularly those who suffer from a severe illness, have a central nervous system (CNS) involvement and neurological manifestations. There is precise and targeted documentation of neurological symptoms with details of clinical, neurological, and electrophysiological findings. This review article thus gives an insight into the neuro-invasive potential of COVID-19 and discusses the possible pathogenesis.

Neurological Involvements of SARS-CoV2 Infection

COVID-19 is a pandemic viral infection caused by a novel coronavirus, SARS-CoV2, which is a global concern of the twenty-first century for its rapid spreading in a short period. Apart from its known acute respiratory involvements, the CNS manifestations of COVID-19 are common. These neurological symptoms are diverse and could range from mild nonspecific or specific symptoms such as the loss of various sensory perceptions, the worrying autoimmune Guillain-Barré syndrome, to the life-threatening acute disseminated encephalomyelitis, and the CNS-mediated respiratory distress. An autopsy report documented the presence of SARS-CoV2 in brain tissues of a COVID-19 patient. However, there is no definite conclusion on the mechanisms of SARS-CoV2 neuroinvasion. These proposed mechanisms include the direct viral invasion, the systemic blood circulation, or the distribution of infected immune cells. Concerning these different neuropathophysiologies, COVID-19 patients who are presenting with either the early-onset, multiple, and severe CNS symptoms or rapid respiratory deterioration should be suspected for the direct viral neuroinvasion, and appropriate management options should be considered. This article reviews the neurological manifestations, the proposed neuroinvasive mechanisms, and the potential neurological sequelae of SARS-CoV2.

Overview of COVID-19 and neurological complications

The sudden and storming onset of coronavirus 2 infection (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) was associated by severe acute respiratory syndrome. Recently, corona virus disease 19 (COVID-19) has appeared as a pandemic throughout the world. The mutational nature of the virus, along with the different means of entering and spreading throughout the body has involved different organs. Thus, patients are faced with a wide range of symptoms and signs. Neurological symptoms, such as anosmia, agnosia, stroke, paralysis, cranial nerve deficits, encephalopathy, meningitis, delirium and seizures, are reported as common complications affecting the course of the disease and its treatment. In this review, special attention was paid to reports that addressed the acute or chronic neurological manifestations in COVID-19 patients who may present acute respiratory syndrome or not. Moreover, we discussed the central (CNS) and peripheral nervous system (PNS) complications in SARS-Cov2-infected patients, and also the pathophysiology of neurological abnormalities in COVID-19.

Blood Biomarkers for Detection of Brain Injury in COVID-19 Patients

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus attacks multiple organs of coronavirus disease 2019 (COVID-19) patients, including the brain. There are worldwide descriptions of neurological deficits in COVID-19 patients. Central nervous system (CNS) symptoms can be present early in the course of the disease. As many as 55% of hospitalized COVID-19 patients have been reported to have neurological disturbances three months after infection by SARS-CoV-2. The mutability of the SARS-COV-2 virus and its potential to directly affect the CNS highlight the urgency of developing technology to diagnose, manage, and treat brain injury in COVID-19 patients. The pathobiology of CNS infection by SARS-CoV-2 and the associated neurological sequelae of this infection remain poorly understood. In this review, we outline the rationale for the use of blood biomarkers (BBs) for diagnosis of brain injury in COVID-19 patients, the research needed to incorporate their use into clinical practice, and the improvements in patient management and outcomes that can result. BBs of brain injury could potentially provide tools for detection of brain injury in COVID-19 patients. Elevations of BBs have been reported in cerebrospinal fluid (CSF) and blood of COVID-19 patients. BB proteins have been analyzed in CSF to detect CNS involvement in patients with infectious diseases, including human immunodeficiency virus and tuberculous meningitis. BBs are approved by the U.S. Food and Drug Administration for diagnosis of mild versus moderate traumatic brain injury and have identified brain injury after stroke, cardiac arrest, hypoxia, and epilepsy. BBs, integrated with other diagnostic tools, could enhance understanding of viral mechanisms of brain injury, predict severity of neurological deficits, guide triage of patients and assignment to appropriate medical pathways, and assess efficacy of therapeutic interventions in COVID-19 patients.

SARS-CoV-2: Immune Response Elicited by Infection and Development of Vaccines and Treatments

The World Health Organization (WHO) announced in March a pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This new infectious disease was named Coronavirus Disease 19 (COVID-19), and at October 2020, more than 39,000,000 cases of SARS-CoV-2 have been detected worldwide leading to near 1,100,000 deaths. Clinically, COVID-19 is characterized by clinical manifestations, such as fever, dry cough, headache, and in more severe cases, respiratory distress. Moreover, neurological-, cardiac-, and renal-related symptoms have also been described. Clinical evidence suggests that migration of immune cells to the affected organs can produce an exacerbated release of proinflammatory mediators that contribute to disease and render the immune response as a major player during the development of the COVID-19 disease. Due to the current sanitary situation, the development of vaccines is imperative. Up to the date, 42 prototypes are being tested in humans in different clinical stages, with 10 vaccine candidates undergoing evaluation in phase III clinical trials. In the same way, the search for an effective treatment to approach the most severe cases is also in constant advancement. Several potential therapies have been tested since COVID-19 was described, including antivirals, antiparasitic and immune modulators. Recently, clinical trials with hydroxychloroquine-a promising drug in the beginning-were suspended. In addition, the Food and Drug Administration (FDA) approved convalescent serum administration as a treatment for SARS-CoV-2 patients. Moreover, monoclonal antibody therapy is also under development to neutralize the virus and prevent infection. In this article, we describe the clinical manifestations and the immunological information available about COVID-19 disease. Furthermore, we discuss current therapies under study and the development of vaccines to prevent this disease.

Multidisciplinary Approach to the Diagnosis and In-Hospital Management of COVID-19 Infection: A Narrative Review

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 or COVID-19 disease) was declared a pandemic on 11th March 2020 by the World Health Organization. This unprecedented circumstance has challenged hospitals' response capacity, requiring significant structural and organizational changes to cope with the surge in healthcare demand and to minimize in-hospital risk of transmission. As our knowledge advances, we now understand that COVID-19 is a multi-systemic disease rather than a mere respiratory tract infection, therefore requiring holistic care and expertise from various medical specialties. In fact, the clinical spectrum of presentation ranges from respiratory complaints to gastrointestinal, cardiac or neurological symptoms. In addition, COVID-19 pandemic has created a global burden of mental illness that affects the general population as well as healthcare practitioners. The aim of this manuscript is to provide a comprehensive and multidisciplinary insight into the complexity of this disease, reviewing current scientific evidence on COVID-19 management and treatment across several medical specialties involved in the in-hospital care of these patients.

Recent progress in translational engineered in vitro models of the central nervous system

The complexity of the human brain poses a substantial challenge for the development of models of the CNS. Current animal models lack many essential human characteristics (in addition to raising operational challenges and ethical concerns), and conventional in vitro models, in turn, are limited in their capacity to provide information regarding many functional and systemic responses. Indeed, these challenges may underlie the notoriously low success rates of CNS drug development efforts. During the past 5 years, there has been a leap in the complexity and functionality of in vitro systems of the CNS, which have the potential to overcome many of the limitations of traditional model systems. The availability of human-derived induced pluripotent stem cell technology has further increased the translational potential of these systems. Yet, the adoption of state-of-the-art in vitro platforms within the CNS research community is limited. This may be attributable to the high costs or the immaturity of the systems. Nevertheless, the costs of fabrication have decreased, and there are tremendous ongoing efforts to improve the quality of cell differentiation. Herein, we aim to raise awareness of the capabilities and accessibility of advanced in vitro CNS technologies. We provide an overview of some of the main recent developments (since 2015) in in vitro CNS models. In particular, we focus on engineered in vitro models based on cell culture systems combined with microfluidic platforms (e.g. 'organ-on-a-chip' systems). We delve into the fundamental principles underlying these systems and review several applications of these platforms for the study of the CNS in health and disease. Our discussion further addresses the challenges that hinder the implementation of advanced in vitro platforms in personalized medicine or in large-scale industrial settings, and outlines the existing differentiation protocols and industrial cell sources. We conclude by providing practical guidelines for laboratories that are considering adopting organ-on-a-chip technologies.

SARS-CoV-2 pathophysiology and its clinical implications: An integrative overview of the pharmacotherapeutic management of COVID-19

Common manifestations of COVID-19 are respiratory and can extend from mild symptoms to severe acute respiratory distress. The severity of the illness can also extend from mild disease to life-threatening acute respiratory distress syndrome (ARDS). SARS-CoV-2 infection can also affect the gastrointestinal tract, liver and pancreatic functions, leading to gastrointestinal symptoms. Moreover, SARS-CoV-2 can cause central and peripheral neurological manifestations, affect the cardiovascular system and promote renal dysfunction. Epidemiological data have indicated that cancer patients are at a higher risk of contracting the SARS-CoV-2 virus. Considering the multitude of clinical symptoms of COVID-19, the objective of the present review was to summarize their pathophysiology in previously healthy patients, as well as in those with comorbidities. The present review summarizes the current, though admittedly fluid knowledge on the pathophysiology and symptoms of COVID-19 infection. Although unclear issues still remain, the present study contributes to a more complete understanding of the disease, and may drive the direction of new research. The recognition of the severity of the clinical symptoms of COVID-19 is crucial for the specific therapeutic management of affected patients.

Emergent Viral Infections of the CNS

Biological evolution of the microbiome continually drives the emergence of human viral pathogens, a subset of which attack the nervous system. The sheer number of pathogens that have appeared, along with their abundance in the environment, demand our attention. For the most part, our innate and adaptive immune systems have successfully protected us from infection; however, in the past 5 decades, through pathogen mutation and ecosystem disruption, a dozen viruses emerged to cause significant neurologic disease. Most of these pathogens have come from sylvatic reservoirs having made the energetically difficult, and fortuitously rare, jump into humans. But the human microbiome is also replete with agents already adapted to the host that need only minor mutations to create neurotropic/toxic agents. While each host/virus symbiosis is unique, this review examines virologic and immunologic principles that govern the pathogenesis of different viral CNS infections that were described in the past 50 years (Influenza, West Nile Virus, Zika, Rift Valley Fever Virus, Hendra/Nipah, Enterovirus-A71/-D68, Human parechovirus, HIV, and SARS-CoV). Knowledge of these pathogens provides us the opportunity to respond and mitigate infection while at the same time prepare for inevitable arrival of unknown agents.

Neurological associations of COVID-19

BACKGROUND

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is of a scale not seen since the 1918 influenza pandemic. Although the predominant clinical presentation is with respiratory disease, neurological manifestations are being recognised increasingly. On the basis of knowledge of other coronaviruses, especially those that caused the severe acute respiratory syndrome and Middle East respiratory syndrome epidemics, cases of CNS and peripheral nervous system disease caused by SARS-CoV-2 might be expected to be rare.

RECENT DEVELOPMENTS

A growing number of case reports and series describe a wide array of neurological manifestations in 901 patients, but many have insufficient detail, reflecting the challenge of studying such patients. Encephalopathy has been reported for 93 patients in total, including 16 (7%) of 214 hospitalised patients with COVID-19 in Wuhan, China, and 40 (69%) of 58 patients in intensive care with COVID-19 in France. Encephalitis has been described in eight patients to date, and Guillain-Barré syndrome in 19 patients. SARS-CoV-2 has been detected in the CSF of some patients. Anosmia and ageusia are common, and can occur in the absence of other clinical features. Unexpectedly, acute cerebrovascular disease is also emerging as an important complication, with cohort studies reporting stroke in 2-6% of patients hospitalised with COVID-19. So far, 96 patients with stroke have been described, who frequently had vascular events in the context of a pro-inflammatory hypercoagulable state with elevated C-reactive protein, D-dimer, and ferritin. WHERE NEXT?: Careful clinical, diagnostic, and epidemiological studies are needed to help define the manifestations and burden of neurological disease caused by SARS-CoV-2. Precise case definitions must be used to distinguish non-specific complications of severe disease (eg, hypoxic encephalopathy and critical care neuropathy) from those caused directly or indirectly by the virus, including infectious, para-infectious, and post-infectious encephalitis, hypercoagulable states leading to stroke, and acute neuropathies such as Guillain-Barré syndrome. Recognition of neurological disease associated with SARS-CoV-2 in patients whose respiratory infection is mild or asymptomatic might prove challenging, especially if the primary COVID-19 illness occurred weeks earlier. The proportion of infections leading to neurological disease will probably remain small. However, these patients might be left with severe neurological sequelae. With so many people infected, the overall number of neurological patients, and their associated health burden and social and economic costs might be large. Health-care planners and policy makers must prepare for this eventuality, while the many ongoing studies investigating neurological associations increase our knowledge base.

Intensive Care Admission and Early Neuro-Rehabilitation. Lessons for COVID-19?

Coronavirus disease 2019 (COVID-19) requires admission to intensive care (ICU) for the management of acute respiratory distress syndrome in about 5% of cases. Although our understanding of COVID-19 is still incomplete, a growing body of evidence is indicating potential direct deleterious effects on the central and peripheral nervous systems. Indeed, complex and long-lasting physical, cognitive, and functional impairments have often been observed after COVID-19. Early (defined as during and immediately after ICU discharge) rehabilitative interventions are fundamental for reducing the neurological burden of a disease that already heavily affects lung function with pulmonary fibrosis as a possible long-term consequence. In addition, ameliorating neuromuscular weakness with early rehabilitation would improve the efficiency of respiratory function as respiratory muscle atrophy worsens lung capacity. This review briefly summarizes the polymorphic burden of COVID-19 and addresses possible early interventions that could minimize the neurological and systemic impact. In fact, the benefits of early multidisciplinary rehabilitation after an ICU stay have been shown to be advantageous in several clinical conditions making an early rehabilitative approach generalizable and desirable to physicians from a wide range of different specialties.

SARS-CoV-2 and the Nervous System: From Clinical Features to Molecular Mechanisms

Increasing evidence suggests that Severe Acute Respiratory Syndrome-coronavirus-2 (SARS-CoV-2) can also invade the central nervous system (CNS). However, findings available on its neurological manifestations and their pathogenic mechanisms have not yet been systematically addressed. A literature search on neurological complications reported in patients with COVID-19 until June 2020 produced a total of 23 studies. Overall, these papers report that patients may exhibit a wide range of neurological manifestations, including encephalopathy, encephalitis, seizures, cerebrovascular events, acute polyneuropathy, headache, hypogeusia, and hyposmia, as well as some non-specific symptoms. Whether these features can be an indirect and unspecific consequence of the pulmonary disease or a generalized inflammatory state on the CNS remains to be determined; also, they may rather reflect direct SARS-CoV-2-related neuronal damage. Hematogenous versus transsynaptic propagation, the role of the angiotensin II converting enzyme receptor-2, the spread across the blood-brain barrier, the impact of the hyperimmune response (the so-called "cytokine storm"), and the possibility of virus persistence within some CNS resident cells are still debated. The different levels and severity of neurotropism and neurovirulence in patients with COVID-19 might be explained by a combination of viral and host factors and by their interaction.

SARS-CoV-2 and the Nervous System: From Clinical Features to Molecular Mechanisms

Increasing evidence suggests that Severe Acute Respiratory Syndrome-coronavirus-2 (SARS-CoV-2) can also invade the central nervous system (CNS). However, findings available on its neurological manifestations and their pathogenic mechanisms have not yet been systematically addressed. A literature search on neurological complications reported in patients with COVID-19 until June 2020 produced a total of 23 studies. Overall, these papers report that patients may exhibit a wide range of neurological manifestations, including encephalopathy, encephalitis, seizures, cerebrovascular events, acute polyneuropathy, headache, hypogeusia, and hyposmia, as well as some non-specific symptoms. Whether these features can be an indirect and unspecific consequence of the pulmonary disease or a generalized inflammatory state on the CNS remains to be determined; also, they may rather reflect direct SARS-CoV-2-related neuronal damage. Hematogenous versus transsynaptic propagation, the role of the angiotensin II converting enzyme receptor-2, the spread across the blood-brain barrier, the impact of the hyperimmune response (the so-called "cytokine storm"), and the possibility of virus persistence within some CNS resident cells are still debated. The different levels and severity of neurotropism and neurovirulence in patients with COVID-19 might be explained by a combination of viral and host factors and by their interaction.

Coronaviruses and the central nervous system

Seven coronavirus (CoV) species are known human pathogens: the epidemic viruses SARS-CoV, SARS-CoV-2, and MERS-CoV and those continuously circulating in human populations since initial isolation: HCoV-OC43, HCoV-229E, HCoV-HKU1, and HCoV-NL63. All have associations with human central nervous system (CNS) dysfunction. In infants and young children, the most common CNS phenomena are febrile seizures; in adults, non-focal abnormalities that may be either neurologic or constitutional. Neurotropism and neurovirulence are dependent in part on CNS expression of cell surface receptors mediating viral entry, and host immune response. In adults, CNS receptors for epidemic viruses are largely expressed on brain vasculature, whereas receptors for less pathogenic viruses are present in vasculature, brain parenchyma, and olfactory neuroepithelium, dependent upon viral species. Human coronaviruses can infect circulating mononuclear cells, but meningoencephalitis is rare. Well-documented human neuropathologies are infrequent and, for SARS, MERS, and COVID-19, can entail cerebrovascular accidents originating extrinsically to brain. There is evidence of neuronal infection in the absence of inflammatory infiltrates with SARS-CoV, and CSF studies of rare patients with seizures have demonstrated virus but no pleocytosis. In contrast to human disease, animal models of neuropathogenesis are well developed, and pathologies including demyelination, neuronal necrosis, and meningoencephalitis are seen with both native CoVs as well as human CoVs inoculated into nasal cavities or brain. This review covers basic CoV biology pertinent to CNS disease; the spectrum of clinical abnormalities encountered in infants, children, and adults; and the evidence for CoV infection of human brain, with reference to pertinent animal models of neuropathogenesis.

Potential neurological effects of severe COVID-19 infection

Coronaviruses (CoVs) are large positive stranded enveloped RNA viruses that generally cause enteric and respiratory diseases in humans and in animals. Most human CoVs have recently attracted global attention to their lethal potential and great infectious capacity. A highly pathogenic CoV, called COVID-19 or SARS-CoV-2, dramatically emerged in December 2019 in Wuhan, China. This new CoV has caused severe pneumonia in China and rapidly spreads around the world, the COVID-19 pandemic. Growing evidence pieces show that viruses, such as CoVs, can enter the central nervous system from different pathways and inducing neurotoxicity. Therefore, it is urgent to make clear whether SARS-CoV-2 has access to the central nervous system and can cause direct neuronal effects. Moreover, a brain-lung-brain axis is been proposed from the scientific community where severe neurological dysfunction and injury are associated with lung injury, and vice versa. In this axis, virus-induced inflammation and oxidative stress could be the common mechanisms responsible for CoV neurological symptoms. Therefore, is important to make clear whether SARS-CoV-2 lung damage can cause direct or indirect neuronal effects.

Fulminant cerebral edema as a lethal manifestation of COVID-19

The contribution of neurological symptomatology to morbidity and mortality after infection with Severe Acute Respiratory Syndrome-associated Coronavirus (SARS CoV II) is ill-defined. We hereby present a case of a 57-year old male patient, in excellent physical condition, who was admitted to the Intensive Care Unit (ICU), with respiratory distress duo to SARS CoV II-induced bilateral pneumonia. After 2 weeks at the ICU, with respiratory conditions improving, the patient developed lethal cerebral edema. This case advocates regular wake-up calls in Coronavirus disease 2019 patients for neurological (radiological) evaluation to provide rapid diagnosis and a therapeutic window for fulminant central nervous system complications.

Neurological features of COVID-19 and their treatment: a review

Severe acute respiratory syndrome-correlated new coronavirus (SARS-Cov-2) infection may result in neurological signs and symptoms through different mechanisms. Although direct infection of the central nervous system is uncertain or very rare and the para-infectious complications (e.g. inflammatory neuropathies) are rare, delirium and septic encephalopathy are common in severely ill patients. Smell dysfunction and headache are very common in mild cases, especially in younger people and females. Muscle pain is common in both mild and severe cases, and in the most compromised patients, it is accompanied by increased creatine kinase levels and by a likely true myopathic damage. Ischemic stroke has been reported as a possible complication of the hypercoagulability associated with severe SARS-Cov-2 infection, but further studies are needed. Most of the neurological manifestations may occur early in the illness. Therefore, during the pandemic period, neurologists need to be involved, alert, and prepared. Neurological practice will not be the same until a vaccine is available.

Neurological involvement in SARS-CoV-2 infection: A clinical systematic review

OBJECTIVE

Reports of neurological involvement during Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection course are increasingly described. The aim of this review is to provide a clinical approach of SARS-CoV-2 neurological complications based on the direct or indirect (systemic/immune-mediated) role of the SARS-CoV-2 in their genesis.

METHODS

A review of the current literature has been carried out up to May 20th 2020 according to the PRISMA guidelines. All case series and reports of adult neurological manifestations associated to SARS-CoV-2 published in English were considered. Review and fundamental research studies on Coronaviruses neuroinvasive potential were analyzed to support pathogenic hypothesis and possible underlying mechanisms. Clinical patterns were subdivided into three groups according to putative underlying mechanisms: direct invasion of central or peripheral nervous system, systemic disorders leading to acute CNS injuries and post-infectious neurological syndromes (PINS).

RESULTS

Sixteen case series and 26 case reports for a total of 903 patients were identified presenting with neurological involvement during SARS-CoV-2 infection. Hypo/anosmia and dys/ageusia were found in 826 patients and mainly attributed to direct viral invasion. Cerebrovascular complications occurred in 51 patients and related to viral infection associated systemic inflammation. PINS were described in only 26 patients. A wide heterogeneity of these reports emerged concerning the extension of the clinical examination and ancillary exams performed.

CONCLUSIONS

Neurological complications of SARS-CoV-2 are mainly related to olfactory and gustatory sensory perception disorders through possible direct nervous system invasion while cerebrovascular disease and PINS are rare and due to distinct and indirect pathophysiological mechanisms.

The emergence of a novel coronavirus (SARS-CoV-2) disease and their neuroinvasive propensity may affect in COVID-19 patients

An outbreak of a novel coronavirus (SARS‐CoV‐2) infection has recently emerged and rapidly spreading in humans causing a significant threat to international health and the economy. Rapid assessment and warning are crucial for an outbreak analysis in response to serious public health. SARS‐CoV‐2 shares highly homological sequences with SARS‐CoVs causing highly lethal pneumonia with respiratory distress and clinical symptoms similar to those reported for SARS‐CoV and MERS‐CoV infections. Notably, some COVID‐19 patients also expressed neurologic signs like nausea, headache, and vomiting. Several studies have reported that coronaviruses are not only causing respiratory illness but also invade the central nervous system through a synapse‐connected route. SARS‐CoV infections are reported in both patients and experimental animals' brains. Interestingly, some COVID‐19 patients have shown the presence of SARS‐CoV‐2 virus in their cerebrospinal fluid. Considering the similarities between SARS‐CoV and SARS‐CoV‐2 in various aspects, it remains to clarify whether the potent invasion of SARS‐CoV‐2 may affect in COVID‐19 patients. All these indicate that more detailed criteria are needed for the treatment and the prevention of SARS‐CoV‐2 infected patients. In the absence of potential interventions for COVID‐19, there is an urgent need for an alternative strategy to control the spread of this disease.

Endoscopia digestiva en tiempos de covid-19: Resumen de recomendaciones

La situación actual de pandemia por COVID-19, ha puesto en evidencia las debilidades y necesidades no atendidas del sector salud en Colombia. Salieron a la luz las inequidades de un sistema económico y social, que desde hace varios años venía disminuyendo la protección laboral, económica y jurídica del talento humano en salud del país, que en estos momentos se ven enfrentando una batalla difícil, ante un enemigo todavía poco conocido.

Response to Commentary on "The neuroinvasive potential of SARS-CoV-2 may play a role in the respiratory failure of COVID-19 patients"

In a recent review, we have suggested a neuroinvasive potential of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and its possible role in the causation of acute respiratory failure of coronavirus disease 2019 (COVID‐19) patients (J Med Viol doi: 10.1002/jmv.25728), based upon the clinical and experimental data available on the past SARS‐CoV‐1 and the recent SARS‐CoV‐2 pandemic. In this article, we provide new evidence recently reported regarding the neurotropic potential of SARS‐CoV‐2 and respond to several comments on our previously published article. In addition, we also discuss the peculiar manifestations of respiratory failure in COVID‐19 patients and the possible involvement of nervous system.

New evidence has been available for the neurotropism of SARS‐CoV‐2.

Muscular injuries and reduced sensitivity of nerves may play a role in the respiratory failure.

Potential neuroinvasion of SARS‐CoV‐2 indicates a possible involvement of central factors.