COMPARATIVE EVALUATION AND PROGNOSTIC UTILITY OF NEURONAL INJURY BIOMARKERS IN COVID-19 PATIENTS: A PROSPECTIVE STUDY.

ABSTRACT: Background : COVID-19 disease severity markers include mostly molecules related to not only tissue perfusion, inflammation, and thrombosis, but also biomarkers of neural injury. Clinical and basic research has demonstrated that SARS-COV-2 affects the central nervous system. The aims of the present study were to investigate the role of neural injury biomarkers and to compare them with inflammatory markers in their predictive ability of mortality. Methods : We conducted a prospective observational study in critically ill patients with COVID-19 and in a cohort of patients with moderate/severe disease. S100b, neuron-specific enolase (NSE), and inflammatory markers, including soluble urokinase plasminogen activator receptor (suPAR), were measured on intensive care unit or ward admission, respectively. Statistical comparisons between patient groups were performed for all biomarkers under investigation. Correlations between different biomarkers were tested with Spearman correlation coefficient. Receiver operating characteristic curves were plotted using mortality as the classification variable and the biomarker levels on admission as the prognostic variables. Results : A total of 70 patients with COVID-19 were included in the final analysis. Of all studied biomarkers, s100b had the best predictive ability for death in the intensive care unit, with an area under the curve of 0.73 (0.61-0.83), P = 0.0003. S100b levels correlated with NSE, interleukin (IL)-8, and IL-10 (0.27 < rs < 0.37, P < 0.05), and tended to correlate with suPAR ( rs = 0.26, P = 0.05), but not with the vasopressor dose ( P = 0.62). Conclusion : Among the investigated biomarkers, s100b demonstrated the best predictive ability for death in COVID-19 patients. The overall biomarker profile of the patients implies direct involvement of the nervous system by the novel coronavirus.

Are we sure that the neurological impact of COVID 19 in childhood has not been underestimated?

BACKGROUND: Presently, it is known that, even if less frequently than in adults, children can develop a severe new coronavirus disease 2019 (COVID-19). Children with the SARS-CoV-2 infection can have neurological signs and symptoms of disease more frequently than previously thought, revealing the involvement of the central nervous system, the peripheral nervous system, or both. Aim of this manuscript is to highlight the neurologic complications associated with SARS-CoV-2 among pediatric patients with COVID-19, suggesting when to monitor carefully neurologic development. MAIN FINDINGS: Children with a severe chronic underlying disease, infants and toddlers and those who develop the so-called multisystem inflammatory syndrome (MIS-C) are those with the highest incidence of neurological complications. Fortunately, in most of the cases, neurological manifestations, mainly represented by headache and anosmia, are mild and transient and do not significantly complicate the COVID-19 course. However, in some cases, very severe clinical problems associated with relevant alterations of neuroimaging, electroencephalography, nerve conduction studies and electromyography findings can develop. Generally, almost all the children with COVID-19 and neurological manifestations till now described have made a complete recovery, although in some cases this has occurred after several weeks of treatment. Moreover, COVID-19 infection during pregnancy has been found associated with an increased risk of obstetric complications that can lead to neurological acute and long-term manifestations in neonates. CONCLUSIONS: Based on data showing the neurologic impact of COVID-19 in pediatric age, we suggest monitoring neurological development a few months after healing in pediatric patients who have presented MIS-C, seizures or other neurological manifestations and in children of pregnant women with COVID-19 in order to detect overt and subtle deficits.

Neurologic manifestations of COVID-19 in critically ill patients: results of the prospective multicenter registry PANDEMIC.

BACKGROUND: Neurologic manifestations are increasingly reported in patients with coronavirus disease 2019 (COVID-19). Yet, data on prevalence, predictors and relevance for outcome of neurological manifestations in patients requiring intensive care are scarce. We aimed to characterize prevalence, risk factors and impact on outcome of neurologic manifestations in critically ill COVID-19 patients. METHODS: In the prospective, multicenter, observational registry study PANDEMIC (Pooled Analysis of Neurologic DisordErs Manifesting in Intensive care of COVID-19), we enrolled COVID-19 patients with neurologic manifestations admitted to 19 German intensive care units (ICU) between April 2020 and September 2021. We performed descriptive and explorative statistical analyses. Multivariable models were used to investigate factors associated with disorder categories and their underlying diagnoses as well as to identify predictors of outcome. RESULTS: Of the 392 patients included in the analysis, 70.7% (277/392) were male and the mean age was 65.3 (SD ± 3.1) years. During the study period, a total of 2681 patients with COVID-19 were treated at the ICUs of 15 participating centers. New neurologic disorders were identified in 350 patients, reported by these centers, suggesting a prevalence of COVID-19-associated neurologic disorders of 12.7% among COVID-19 ICU patients. Encephalopathy (46.2%; 181/392), cerebrovascular (41.0%; 161/392) and neuromuscular disorders (20.4%; 80/392) were the most frequent categories identified. Out of 35 cerebrospinal fluid analyses with reverse transcriptase PCR for SARS-COV-2, only 3 were positive. In-hospital mortality was 36.0% (140/389), and functional outcome (mRS 3 to 5) of surviving patients was poor at hospital discharge in 70.9% (161/227). Intracerebral hemorrhage (OR 6.2, 95% CI 2.5-14.9, p < 0.001) and acute ischemic stroke (OR 3.9, 95% CI 1.9-8.2, p < 0.001) were the strongest predictors of poor outcome among the included patients. CONCLUSIONS: Based on this well-characterized COVID-19 ICU cohort, that comprised 12.7% of all severe ill COVID-19 patients, neurologic manifestations increase mortality and morbidity. Since no reliable evidence of direct viral affection of the nervous system by COVID-19 could be found, these neurologic manifestations may for a great part be indirect para- or postinfectious sequelae of the infection or severe critical illness. Neurologic ICU complications should be actively searched for and treated.

Neurological Sequelae of COVID-19.

BACKGROUND: Though primarily a pulmonary disease, Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus can generate devastating disease states that affect multiple organ systems including the central nervous system (CNS). The various neurological disorders associated with COVID-19 range in severity from mild symptoms such as headache, or myalgias to more severe symptoms such as stroke, psychosis, and anosmia. While some of the COVID-19 associated neurological complications are mild and reversible, a significant number of patients suffer from stroke. Studies have shown that COVID-19 infection triggers a wave of inflammatory cytokines that induce endothelial cell dysfunction and generate coagulopathy that increases the risk of stroke or thromboses. Inflammation of the endothelium following infection may also destabilize atherosclerotic plaque and induce thrombotic stroke. Although uncommon, there have also been reports of hemorrhagic stroke associated with COVID-19. The proposed mechanisms include a blood pressure increase caused by infection leading to a reduction in angiotensin converting enzyme-2 (ACE-2) levels that results in an imbalance of the renin-angiotensin system ultimately manifesting inflammation and vasoconstriction. Coagulopathy, as demonstrated by elevated prothrombin time (PT), has also been posited as a factor contributing to hemorrhagics stroke in patients with COVID-19. Other neurological conditions associated with COVID-19 include encephalopathy, anosmia, encephalitis, psychosis, brain fog, headache, depression, and anxiety. Though there are several hypotheses reported in the literature, a unifying pathophysiological mechanism of many of these disorders remains unclear. Pulmonary dysfunction leading to poor oxygenation of the brain may explain encephalopathy and other disorders in COVID-19 patients. Alternatively, a direct invasion of the CNS by the virus or breach of the blood-brain barrier by the systemic cytokines released during infection may be responsible for these conditions. Notwithstanding, the relationship between the inflammatory cytokine levels and conditions such as depression and anxiety is contradictory and perhaps the social isolation during the pandemic may in part be a contributing factor to some of the reported CNS disorders. OBJECTIVE: In this article, we review the current literature pertaining to some of the most significant and common neurological disorders such as ischemic and hemorrhagic stroke, encephalopathy, encephalitis, brain fog, Long COVID, headache, Guillain-Barre syndrome, depression, anxiety, and sleep disorders in the setting of COVID-19. We summarize some of the most relevant literature to provide a better understanding of the mechanistic details regarding these disorders in order to help physicians monitor and treat patients for significant COVID-19 associated neurologic impairments. METHODS: A literature review was carried out by the authors using PubMed with the search terms "COVID-19" and "Neurology", "Neurological Manifestations", "Neuropsychiatric Manifestations", "Stroke", "Encephalopathy", "Headache", "Guillain-Barre syndrome", "Depression", "Anxiety", "Encephalitis", "Seizure", "Spasm", and "ICUAW". Another search was carried out for "Long-COVID" and "Post-Acute COVID-19" and "Neurological Manifestations" or "Neuropsychiatric Manifestations". Articles such as case reports, case series, and cohort studies were included as references. No language restrictions were enforced. In the case of anxiety and depression, attempts were made to focus mainly on articles describing these conditions in infected patients. RESULTS: A total of 112 articles were reviewed. The incidence, clinical outcomes, and pathophysiology of selected neurological disorders are discussed below. Given the recent advent of this disease, the incidence of certain neurologic sequelae was not always available. Putative mechanisms for each condition in the setting of COVID-19 are outlined.

Mechanisms of coronavirus infectious disease 2019-related neurologic diseases.

PURPOSE OF REVIEW: As of January 8, 2022, a global pandemic caused by infection with severe acute respiratory syndrome coronavirus (SARS-CoV)-2, a new RNA virus, has resulted in 304,896,785 cases in over 222 countries and regions, with over 5,500,683 deaths (www.worldometers.info/coronavirus/). Reports of neurological and psychiatric symptoms in the context of coronavirus infectious disease 2019 (COVID-19) range from headache, anosmia, and dysgeusia, to depression, fatigue, psychosis, seizures, delirium, suicide, meningitis, encephalitis, inflammatory demyelination, infarction, and acute hemorrhagic necrotizing encephalopathy. Moreover, 30-50% of COVID-19 survivors develop long-lasting neurologic symptoms, including a dysexecutive syndrome, with inattention and disorientation, and/or poor movement coordination. Detection of SARS-CoV-2 RNA within the central nervous system (CNS) of patients is rare, and mechanisms of neurological damage and ongoing neurologic diseases in COVID-19 patients are unknown. However, studies demonstrating viral glycoprotein effects on coagulation and cerebral vasculature, and hypoxia- and cytokine-mediated coagulopathy and CNS immunopathology suggest both virus-specific and neuroimmune responses may be involved. This review explores potential mechanistic insights that could contribute to COVID-19-related neurologic disease. RECENT FINDINGS: While the development of neurologic diseases during acute COVID-19 is rarely associated with evidence of viral neuroinvasion, new evidence suggests SARS-CoV-2 Spike (S) protein exhibits direct inflammatory and pro-coagulation effects. This, in conjunction with immune dysregulation resulting in cytokine release syndrome (CRS) may result in acute cerebrovascular or neuroinflammatory diseases. Additionally, CRS-mediated loss of blood-brain barrier integrity in specific brain regions may contribute to the expression of proinflammatory mediators by neural cells that may impact brain function long after resolution of acute infection. Importantly, host co-morbid diseases that affect vascular, pulmonary, or CNS function may contribute to the type of neurologic disease triggered by SARS-COV-2 infection. SUMMARY: Distinct effects of SARS-CoV-2 S protein and CNS compartment- and region-specific responses to CRS may underlie acute and chronic neuroinflammatory diseases associated with COVID-19.

Emerging Knowledge of the Neurobiology of COVID-19.

Many patients with COVID-19 will experience acute or longer-term neuropsychiatric complications. The neurobiological mechanisms behind these are beginning to emerge; however, the neurotropic hypothesis is not strongly supported by clinical data. The inflammatory response to SARS-CoV-2 is likely to be responsible for delirium and other common acute neuropsychiatric manifestations. Vascular abnormalities such as endotheliopathies contribute to stroke and cerebral microbleeds, with their attendant neuropsychiatric sequelae. Longer-term neuropsychiatric syndromes fall into 2 broad categories: neuropsychiatric deficits occurring after severe (hospitalized) COVID-19 and "long COVID," which occurs in many patients with a milder acute COVID-19 illness.

Impact of COVID-19 in Immunosuppressed Children With Neuroimmunologic Disorders.

BACKGROUND AND OBJECTIVES: To investigate whether children receiving immunosuppressive therapies for neuroimmunologic disorders had (1) increased susceptibility to SARS-CoV2 infection or to develop more severe forms of COVID-19; (2) increased relapses or autoimmune complications if infected; and (3) changes in health care delivery during the pandemic. METHODS: Patients with and without immunosuppressive treatment were recruited to participate in a retrospective survey evaluating the period from March 14, 2020, to March 30, 2021. Demographics, clinical features, type of immunosuppressive treatment, suspected or confirmed COVID-19 in the patients or cohabitants, and changes in care delivery were recorded. RESULTS: One hundred fifty-three children were included: 84 (55%) female, median age 13 years (interquartile range [8-16] years), 79 (52%) on immunosuppressive treatment. COVID-19 was suspected or confirmed in 17 (11%) (all mild), with a frequency similar in patients with and without immunosuppressive treatment (11/79 [14%] vs 6/74 [8%], p = 0.3085). The frequency of neurologic relapses was similar in patients with (18%) and without (21%) COVID-19. Factors associated with COVID-19 included having cohabitants with COVID-19 (p < 0.001) and lower blood levels of vitamin D (p = 0.039). Return to face-to-face schooling or mask type did not influence the risk of infection, although 43(28%) children had contact with a classmate with COVID-19. Clinic visits changed from face to face to remote for 120 (79%) patients; 110 (92%) were satisfied with the change. DISCUSSION: In this cohort of children with neuroimmunologic disorders, the frequency of COVID-19 was low and not affected by immunosuppressive therapies. The main risk factors for developing COVID-19 were having cohabitants with COVID-19 and low vitamin D levels.

Mini-Review on SARS-CoV-2 Infection and Neurological Manifestations: A Perspective.

The coronavirus, also known as SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona Virus-19), with its rapid rate of transmission, has progressed with a great impact on respiratory function and mortality worldwide. The nasal cavity is the promising gateway of SARS-CoV-2 to reach the brain via systemic circulatory distribution. Recent reports have revealed that the loss of involuntary process of breathing control into the brainstem that results in death is a signal of neurological involvement. Early neurological symptoms, like loss of smell, convulsions, and ataxia, are the clues of the involvement of the central nervous system that makes the entry of SARS-CoV-2 further fatal and life-threatening, requiring artificial respiration and emergency admission in hospitals. Studies performed on patients infected with SARS-CoV-2 has revealed three-stage involvement of the Central Nervous System (CNS) in the progression of SARS-CoV-2 infection: Direct involvement of CNS with headache, ataxia, dizziness, altered or impaired consciousness, acute stroke or seizures as major symptoms, peripheral involvement with impaired taste, smell, vision, and altered nociception, and skeletal muscle impairment that includes skeletal muscle disorders leading to acute paralysis in a particular area of the body. In the previous era, most studied and researched viruses were beta coronavirus and mouse hepatitis virus, which were studied for acute and chronic encephalitis and Multiple Sclerosis (MS). Although the early symptoms of SARS-CoV are respiratory pathogenesis, the differential diagnosis should always be considered for neurological perspective to stop the mortalities.

Worldwide epidemiology of neuro-coronavirus disease in children: lessons for the next pandemic.

PURPOSE OF REVIEW: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has overwhelmed the global community, negatively impacting patient health and research efforts; associated neurological manifestations are a significant cause of morbidity. This review outlines the worldwide epidemiology of neurologic manifestations of different SARS-CoV-2 clinical pediatric phenotypes, including acute coronavirus disease 2019 (COVID-19), multisystem inflammatory syndrome in children (MIS-C) and postacute sequelae of COVID-19 (PASC). We discuss strategies to develop adaptive global research platforms for future investigation into emerging pediatric neurologic conditions. RECENT FINDINGS: Multicenter, multinational studies show that neurological manifestations of acute COVID-19, such as smell/taste disorders, headache, and stroke, are common in hospitalized adults (82%) and children (22%), associated with increased mortality in adults. Neurological manifestations of MIS-C are reported in up to 20% of children, including headache, irritability, and encephalopathy. Data on PASC are emerging and include fatigue, cognitive changes, and headache. Reports of neurological manifestations in each phenotype are limited by lack of pediatric-informed case definitions, common data elements, and resources. SUMMARY: Coordinated, well resourced, multinational investigation into SARS-CoV-2-related neurological manifestations in children is critical to rapid identification of global and region-specific risk factors, and developing treatment and mitigation strategies for the current pandemic and future health neurologic emergencies.

Neurological complications and infection mechanism of SARS-COV-2.

Currently, SARS-CoV-2 has caused a global pandemic and threatened many lives. Although SARS-CoV-2 mainly causes respiratory diseases, growing data indicate that SARS-CoV-2 can also invade the central nervous system (CNS) and peripheral nervous system (PNS) causing multiple neurological diseases, such as encephalitis, encephalopathy, Guillain-Barré syndrome, meningitis, and skeletal muscular symptoms. Despite the increasing incidences of clinical neurological complications of SARS-CoV-2, the precise neuroinvasion mechanisms of SARS-CoV-2 have not been fully established. In this review, we primarily describe the clinical neurological complications associated with SARS-CoV-2 and discuss the potential mechanisms through which SARS-CoV-2 invades the brain based on the current evidence. Finally, we summarize the experimental models were used to study SARS-CoV-2 neuroinvasion. These data form the basis for studies on the significance of SARS-CoV-2 infection in the brain.

Neurological complications after first dose of COVID-19 vaccines and SARS-CoV-2 infection.

Emerging reports of rare neurological complications associated with COVID-19 infection and vaccinations are leading to regulatory, clinical and public health concerns. We undertook a self-controlled case series study to investigate hospital admissions from neurological complications in the 28 days after a first dose of ChAdOx1nCoV-19 (n = 20,417,752) or BNT162b2 (n = 12,134,782), and after a SARS-CoV-2-positive test (n = 2,005,280). There was an increased risk of Guillain-Barré syndrome (incidence rate ratio (IRR), 2.90; 95% confidence interval (CI): 2.15-3.92 at 15-21 days after vaccination) and Bell's palsy (IRR, 1.29; 95% CI: 1.08-1.56 at 15-21 days) with ChAdOx1nCoV-19. There was an increased risk of hemorrhagic stroke (IRR, 1.38; 95% CI: 1.12-1.71 at 15-21 days) with BNT162b2. An independent Scottish cohort provided further support for the association between ChAdOx1nCoV and Guillain-Barré syndrome (IRR, 2.32; 95% CI: 1.08-5.02 at 1-28 days). There was a substantially higher risk of all neurological outcomes in the 28 days after a positive SARS-CoV-2 test including Guillain-Barré syndrome (IRR, 5.25; 95% CI: 3.00-9.18). Overall, we estimated 38 excess cases of Guillain-Barré syndrome per 10 million people receiving ChAdOx1nCoV-19 and 145 excess cases per 10 million people after a positive SARS-CoV-2 test. In summary, although we find an increased risk of neurological complications in those who received COVID-19 vaccines, the risk of these complications is greater following a positive SARS-CoV-2 test.

COVID-19 and its effects on neurological functions.

Ever since the first reported case series on SARS-CoV-2-induced neurological manifestation in Wuhan, China in April 2020, various studies reporting similar as well as diverse symptoms of COVID-19 infection relating to the nervous system were published. Since then, scientists started to uncover the mechanism as well as pathophysiological impacts it has on the current understanding of the disease. SARS-CoV-2 binds to the ACE2 receptor which is present in certain parts of the body which are responsible for regulating blood pressure and inflammation in a healthy system. Presence of the receptor in the nasal and oral cavity, brain, and blood allows entry of the virus into the body and cause neurological complications. The peripheral and central nervous system could also be invaded directly in the neurogenic or hematogenous pathways, or indirectly through overstimulation of the immune system by cytokines which may lead to autoimmune diseases. Other neurological implications such as hypoxia, anosmia, dysgeusia, meningitis, encephalitis, and seizures are important symptoms presented clinically in COVID-19 patients with or without the common symptoms of the disease. Further, patients with higher severity of the SARS-CoV-2 infection are also at risk of retaining some neurological complications in the long-run. Treatment of such severe hyperinflammatory conditions will also be discussed, as well as the risks they may pose to the progression of the disease. For this review, articles pertaining information on the neurological manifestation of SARS-CoV-2 infection were gathered from PubMed and Google Scholar using the search keywords "SARS-CoV-2", "COVID-19", and "neurological dysfunction". The findings of the search were filtered, and relevant information were included.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil.

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

Complication and Sequelae of COVID-19: What Should We Pay Attention to in the Post-Epidemic Era.

COVID-19 is widespread worldwide and seriously affects the daily life and health of humans. Countries around the world are taking necessary measures to curb the spread. However, COVID-19 patients often have at least one organ complication and sequelae in addition to respiratory symptoms. Controlling the epidemic is only a phased victory, and the complication and sequelae of COVID-19 will need more attention in the post-epidemic era. We collected general information from over 1000 articles published in 2020 after the COVID-19 outbreak and systematically analyzed the complication and sequelae associated with eight major systems in COVID-19 patients caused by ACE2 intervention in the RAS regulatory axis. The autoimmune response induced by 2019-nCoV attacks and damages the normal tissues and organs of the body. Our research will help medical workers worldwide address COVID-19 complication and sequelae.

Understanding the Role of Blood Vessels in the Neurologic Manifestations of Coronavirus Disease 2019 (COVID-19).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was originally identified as an outbreak in Wuhan, China, toward the end of 2019 and quickly became a global pandemic, with a large death toll. Originally identified as a respiratory disease, similar to previously discovered SARS and Middle East respiratory syndrome (MERS), concern has since been raised about the effects of SARS-CoV-2 infection on the vasculature. This viral-vascular involvement is of particular concern with regards to the small vessels present in the brain, with mounting evidence demonstrating that SARS-CoV-2 is capable of crossing the blood-brain barrier. Severe symptoms, termed coronavirus disease 2019 (COVID-19), often result in neurologic complications, regardless of patient age. These neurologic complications range from mild to severe across all demographics; however, the long-term repercussions of neurologic involvement on patient health are still unknown.

[Neurology and COVID-19: Case Series of Neurological Complications in 96 patients Admitted at a University Hospital]. / Neurología hospitalaria y COVID-19: serie de 96 pacientes evaluados en un hospital universitario.

BACKGROUND: There are multisystemic consequences secondary to SARS- CoV-2 infection. AIM: To characterize neurological complications in patients admitted due to SARS-CoV-2 infection. METHODS: Review of medical records of patients aged over 15 years with COVID-19 evaluated by the neurology team between April and August 2020 at a university hospital. Severity of the infection, referral reasons, neurological diagnoses and laboratory results were registered. The diagnoses were defined by consensus among the members of the hospital neurology group. Cerebrovascular and inflammatory diseases of the central and peripheral nervous system were defined as "probably associated" or "possibly associated" to COVID-19. RESULTS: Ninety-six patients had at least 1 new neu- rological complication. 74% were admitted due to pneumonia and 20% due to a neurological disease. The most common reasons for neurological referral were impaired consciousness (39%), focal neurological deficit (24%), headache (9%) and seizures (5%). The most relevant neurological diagnoses were delirium in 48 patients, stroke in 24, critical illness polyneuropathy and myopathy in 17, seizures in 14, brachial plexopathy in 3, compressive neuropathies in 5, encephalitis in 1, possible vasculitis in 1 and Guillain-Barré syndrome in 1. Stroke and epilepsy were associated with increased length of hospital stay, but without differences in mortality. CONCLUSIONS: The spectrum of neurological complications of COVID-19 is wide. There are clinical entities typical of critically ill patients and also diseases associated directly and indirectly with the SARS-CoV2 infection.

Cellular and Molecular Effects of SARS-CoV-2 Linking Lung Infection to the Brain.

In December 2019, a new viral disease emerged and quickly spread all around the world. In March 2020, the COVID-19 outbreak was classified as a global pandemic and by June 2021, the number of infected people grew to over 170 million. Along with the patients' mild-to-severe respiratory symptoms, reports on probable central nervous system (CNS) effects appeared shortly, raising concerns about the possible long-term detrimental effects on human cognition. It remains unresolved whether the neurological symptoms are caused directly by the SARS-CoV-2 infiltration in the brain, indirectly by secondary immune effects of a cytokine storm and antibody overproduction, or as a consequence of systemic hypoxia-mediated microglia activation. In severe COVID-19 cases with impaired lung capacity, hypoxia is an anticipated subsidiary event that can cause progressive and irreversible damage to neurons. To resolve this problem, intensive research is currently ongoing, which seeks to evaluate the SARS-CoV-2 virus' neuroinvasive potential and the examination of the antibody and autoantibody generation upon infection, as well as the effects of prolonged systemic hypoxia on the CNS. In this review, we summarize the current research on the possible interplay of the SARS-CoV-2 effects on the lung, especially on alveolar macrophages and direct and indirect effects on the brain, with special emphasis on microglia, as a possible culprit of neurological manifestation during COVID-19.

Neuropathology and Inflammatory Cell Characterization in 10 Autoptic COVID-19 Brains.

COVID-19 presents with a wide range of clinical neurological manifestations. It has been recognized that SARS-CoV-2 infection affects both the central and peripheral nervous system, leading to smell and taste disturbances; acute ischemic and hemorrhagic cerebrovascular disease; encephalopathies and seizures; and causes most surviving patients to have long lasting neurological symptoms. Despite this, typical neuropathological features associated with the infection have still not been identified. Studies of post-mortem examinations of the cerebral cortex are obtained with difficulty due to laboratory safety concerns. In addition, they represent cases with different neurological symptoms, age or comorbidities, thus a larger number of brain autoptic data from multiple institutions would be crucial. Histopathological findings described here are aimed to increase the current knowledge on neuropathology of COVID-19 patients. We report post-mortem neuropathological findings of ten COVID-19 patients. A wide range of neuropathological lesions were seen. The cerebral cortex of all patients showed vascular changes, hyperemia of the meninges and perivascular inflammation in the cerebral parenchyma with hypoxic neuronal injury. Perivascular lymphocytic inflammation of predominantly CD8-positive T cells mixed with CD68-positive macrophages, targeting the disrupted vascular wall in the cerebral cortex, cerebellum and pons were seen. Our findings support recent reports highlighting a role of microvascular injury in COVID-19 neurological manifestations.

Post-infectious inflammatory syndrome associated with SARS-CoV-2 in a paediatric patient with Down syndrome.

Neurological complications of SARS-CoV-2 continue to be recognised. In children, neurological phenomenon has been reported generally in the acute infectious period. It is possible that SARS-CoV-2 could trigger an immune-mediated post-infectious phenomenon. Here, we present a unique case of post-infectious marantic cardiac lesion causing cerebrovascular accident in a patient with Down syndrome.