Does SARS-Cov-2 invade the brain? Translational lessons from animal models

Current opinion in neurological manifestations of SARS-CoV-2 infection

Neurological symptoms occur in approximately one-third of hospitalized patients with coronavirus disease 2019 (COVID-19). Among these symptoms, hypoxic encephalopathy develops in one-fifth of severe cases, while ischemic strokes due to thrombotic complications are common in one-third of COVID-19 intensive care patients. Brain involvement of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is eventuated by several routes, including hematogenous spread, transsynaptic entry through infected neurons, olfactory nerve, ocular epithelium, vascular endothelium, and impaired blood–brain barrier. Besides the high angiotensin-converting enzyme-2 (ACE2) binding affinity, and FURIN preactivation, SARS-CoV-2 maintains efficient neuronal entry while evading immune surveillance by using basigin and neuropilin-1 receptors. However, the neurological manifestations and their pathogenic mechanisms are still debated in COVID-19 patients.

Neurological manifestations of COVID-19: with emphasis on Iranian patients

The novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has instigated a global pandemic as a formidable and highly contagious infectious disease. Although the respiratory system remains the most frequently affected organ, several case reports have revealed that the complications are not merely limited to the respiratory system, and neurotropic and neuroinvasive properties have also been observed, leading to neurological diseases. In the present paper, it was intended to review the possible neuroinvasive routes of SARS-CoV-2 and its mechanisms that may cause neurological damage. Additionally, the neurological manifestations of COVID-19 across the globe were discussed with emphasis on Iran, while highlighting the impact of SARS-CoV-2 on the central and peripheral nervous systems.

How Does COVID-19 Affect the Neurobiology of Suicide?

PURPOSE OF REVIEW

The aim of this review was to analyze COVID-19 effect on the biological features of suicidal vulnerability and its interaction with suicide-related biological pathways. We carried out a narrative review of international publications on the interactions of COVID-19 with the biological bases of suicide.

RECENT FINDINGS

We hypothesize that SARS-CoV-2 interacts with multiple biological processes that underlie suicidal behavior, such as the renin-angiotensin system, nicotinic receptors, and central and systemic inflammation. Social distancing measures may also worsen subjective or objective social disconnection, thus increasing the risk of suicide. Interestingly, the drugs used to prevent suicide could be promising options to counteract brain damage caused by this coronavirus. SARS-CoV-2 interacts with multiple biological pathways involved in suicide and opens a new window for understanding the suicidal process. The development of suicide prevention treatments in the context of a pandemic may benefit from knowledge on these interactions.

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.

Facemasks and face recognition: Potential impact on synaptic plasticity

Visual recognition of facial expression modulates our social interactions. Compelling experimental evidence indicates that face conveys plenty of information that are fundamental for humans to interact. These are encoded at neural level in specific cortical and subcortical brain regions through activity- and experience-dependent synaptic plasticity processes. The current pandemic, due to the spread of SARS-CoV-2 infection, is causing relevant social and psychological detrimental effects. The institutional recommendations on physical distancing, namely social distancing and wearing of facemasks are effective in reducing the rate of viral spread. However, by impacting social interaction, facemasks might impair the neural responses to recognition of facial cues that are overall critical to our behaviors. In this survey, we briefly review the current knowledge on the neurobiological substrate of facial recognition and discuss how the lack of salient stimuli might impact the ability to retain and consolidate learning and memory phenomena underlying face recognition. Such an "abnormal" visual experience raises the intriguing possibility of a "reset" mechanism, a renewed ability of adult brain to undergo synaptic plasticity adaptations.

How Do Inflammatory Mediators, Immune Response and Air Pollution Contribute to COVID-19 Disease Severity? A Lesson to Learn

Inflammatory and immune processes are defensive mechanisms that aim to remove harmful agents. As a response to infections, inflammation and immune response contribute to the pathophysiological mechanisms of diseases. Coronavirus disease 2019 (COVID-19), whose underlying mechanisms remain not fully elucidated, has posed new challenges for the knowledge of pathophysiology. Chiefly, the inflammatory process and immune response appear to be unique features of COVID-19 that result in developing a hyper-inflammatory syndrome, and air pollution, the world's largest health risk factor, may partly explain the behaviour and fate of COVID-19. Understanding the mechanisms involved in the progression of COVID-19 is of fundamental importance in order to avoid the late stage of the disease, associated with a poor prognosis. Here, the role of the inflammatory and immune mediators in COVID-19 pathophysiology is discussed.

Sleep quality deterioration in middle-aged and older adults living in a rural Ecuadorian village severely struck by the SARS-CoV-2 pandemic. A population-based longitudinal prospective study

Study objectives

This study assessed changes in sleep quality before and after the peak of the SARS-CoV-2 pandemic in community-dwellers enrolled in the Atahualpa Project.

Methods

Atahualpa residents aged ≥40 were eligible if they had a Pittsburgh Sleep Quality Index (PSQI) nine months before the pandemic and a lateral flow-based test for identification of SARS-CoV-2 antibodies during the peak of the pandemic. Six months later, individuals completed a follow-up PSQI. The independent relationship between SARS-CoV-2 infection and deterioration in sleep quality was assessed by fitting logistic mixed models for longitudinal data.

Results

Of 639 participants (mean age at baseline: 59±12.8 years), 325 (51%) had SARS-CoV-2 antibodies. A total of 185 (29%) individuals at baseline and 311 (49%) at follow-up were poor sleepers (p<0.001). Mixed logistic regression models demonstrated a significant increase in poor sleepers at follow-up (OR: 2.85; 95% C.I.: 2.16 – 3.75), which was more marked among SARS-CoV-2 seropositive subjects (OR: 3.8; 95% C.I.: 2.48 – 5.81). The adjusted proportion of poor sleepers increased from 29% to 56.2% (95% C.I.: 50.9 – 61.6%) among SARS-CoV-2 seropositive individuals, but only to 40.7% (95% C.I.: 35.3 – 46.1%) in their seronegative counterparts (p<0.001). Likewise, progression from a good to a poor sleeper status was higher among seropositive individuals than in their seronegative counterparts (38.1% versus 22.3%; p<0.001), after adjusting for relevant covariates.

Conclusions

This study shows a deleterious effect of SARS-CoV-2 in sleep quality. An effect of SARS-CoV-2 in disrupting sleep-related pathways cannot be ruled out.

Clinical features of SARS-CoV-2-associated encephalitis and meningitis amid COVID-19 pandemic

BACKGROUND

Since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic, numerous studies have been published on SARS-CoV-2-related encephalitis/meningitis, but it has not been established if there are specific clinical characteristics of encephalitis/meningitis associated with SARS-CoV-2 infection.

AIM

To identify the specific clinical features of cases of encephalitis/meningitis associated with SARS-CoV-2 infection in the context of this virus infection pandemic and investigate their relationship with SARS-CoV-2 infection.

METHODS

We searched PubMed, and included single case reports and case series with full text in English, reporting original data of coronavirus disease-19 (COVID-19) patients with encephalitis/meningitis and a confirmed recent SARS-CoV-2 infection. Clinical data were extracted.

RESULTS

We identified 22 articles (18 single case reports and 4 case series) reporting on a total of 32 encephalitis/meningitis patients with confirmed SARS-CoV-2 infection. SARS-CoV-2 infection was confirmed through reverse transcriptase-polymerase-chain-reaction (RT-PCR) in 96.88% of cases. A total of 22 (68.75%) patients had symptoms of SARS-CoV-2 infection in about 1 wk (7.91 d) preceding the onset of neurologic symptoms. The most common neurological symptoms were consciousness disturbance (59.38%), seizure (21.88%), delirium (18.75%), and headache (18.75%). Four cases were confirmed by positive RT-PCR results in cerebrospinal fluid (CSF), one was confirmed by positive RT-PCR results in postoperative brain tissue, and one by the presence of SARS-CoV-2 antibodies in CSF. The mainly damaged targets identified by neuroimaging included the temporal lobe (15.63%), white matter (12.5%), frontal lobe (9.38%), corpus callosum (9.38%), and cervical spinal cord (9.38%). Eighty percent of patients had electroencephalograms that showed a diffuse slow wave. Twenty-eight (87.5%) patients were administered with specific treatment. The majority (65.63%) of patients improved following systemic therapy.

CONCLUSION

Encephalitis/meningitis is the common neurological complication in patients with COVID-19. The appropriate use of definitions and exclusion of potential similar diseases are important to reduce over-diagnosis of SARS-CoV-2 associated encephalitis or meningitis.

COVID-19 and stroke: from the cases to the causes

During COVID-19 pandemic, a wide variety of stroke typologies have been described in patients affected by SARS-CoV-2. Investigating the case reports of acute stroke in COVID-19 patients, published since the beginning of the pandemic, we tried to trace the pathogenic mechanisms of stroke during SARS-CoV-2 infection. We conducted a systematic review analyzing demographic data, cerebrovascular risk factors, NIHSS score, vascular territory involvement and laboratory findings of 168 patients described in 89 studies, from a pool of 1243 records. Based on our results, we have identified different stroke profiles: (1) cerebral large vessel disease (CLVD) profile with a low disability, simultaneous onset of COVID-19 and stroke symptoms, good outcome and low serum levels of D-dimer and CRP; (2) intracranial bleeding (IB) profile with high disability, poor outcome and low levels of serum markers of inflammation and coagulopathy; (3) CLVD profile with a short time-lapse between COVID-19 symptoms and stroke onset, high neurological disability and very high systemic inflammatory markers; (4) multiple thrombo-embolic disease (MTED) profile with older patients, many comorbidities, disabling stroke, poor outcome, evident alteration of coagulation tests and high serum levels of both D-dimer and CRP. We therefore summarized these different profiles in a spectrum similar to that of visible light, where the violet-blue band included IB and CSVD with low inflammation and prothrombotic activity, the green-yellow band included CLVD with high inflammation and moderate prothrombotic activity and the orange-red band for MTED with moderate-high levels of inflammation and very high prothrombotic activity.

Cognitive decline among individuals with history of mild symptomatic SARS-CoV-2 infection: A longitudinal prospective study nested to a population cohort

BACKGROUND AND PURPOSE

Neurological complications of SARS-CoV-2 infection are noticed among critically ill patients soon after disease onset. Information on delayed neurological sequelae of SARS-CoV-2 infection is nil. Following a longitudinal study design, the occurrence of cognitive decline among individuals with a history of mild symptomatic SARS-CoV-2 infection was assessed.

METHODS

Stroke- and seizure-free Atahualpa residents aged ≥40 years, who had pre-pandemic cognitive assessments as well as normal brain magnetic resonance imaging and electroencephalogram recordings, underwent repeated evaluations 6 months after a SARS-CoV-2 outbreak infection in Atahualpa. Patients requiring oxygen therapy, hospitalization, and those who had initial neurological manifestations were excluded. Cognitive decline was defined as a reduction in the Montreal Cognitive Assessment (MoCA) score between the post-pandemic and pre-pandemic assessments that was ≥4 points greater than the reduction observed between two pre-pandemic MoCAs. The relationship between SARS-CoV-2 infection and cognitive decline was assessed by fitting logistic mixed models for longitudinal data as well as exposure-effect models.

RESULTS

Of 93 included individuals (mean age 62.6 ± 11 years), 52 (56%) had a history of mild symptomatic SARS-CoV-2 infection. Post-pandemic MoCA decay was worse in seropositive individuals. Cognitive decline was recognized in 11/52 (21%) seropositive and 1/41 (2%) seronegative individuals. In multivariate analyses, the odds for developing cognitive decline were 18.1 times higher among SARS-CoV-2 seropositive individuals (95% confidence interval 1.75-188; p = 0.015). Exposure-effect models confirmed this association (β = 0.24; 95% confidence interval 0.07-0.41; p = 0.006).

CONCLUSIONS

This study provides evidence of cognitive decline among individuals with mild symptomatic SARS-CoV-2 infection. The pathogenesis of this complication remains unknown.

Home quarantine in COVID-19: A study on 50 consecutive patients in Austria

A cohort of the first 50 COVID-19 patients in East Tyrol, a region in the southwest of Austria, were monitored in home quarantine. Specific viral ribonucleic acid was detected in throat swabs and stool samples. Analysis indicated a median virus shedding duration of 13 days; however, statistical outliers highlight the importance of consequent testing. This underlines the need of negative throat swabs prior to removing quarantine. We monitored the disease's characteristics via an in-house score called Corona Severity Index, in order to predict an aggravation of the disease. Special attention was paid to early symptoms, such as headache, which appeared to be significantly more common in younger patients (p=0.019). Anosmia and ageusia showed a predominance in female patients (p=0.028). Investigation revealed seven relapses and viral shedding fluctuation in four cases. A follow-up examination shed light on seroconversion which could be observed in 35 of 40 participants. This further clarifies the necessity of establishing discharge standards and follow-up management for COVID-19 patients.

Multiple Neuroinvasive Pathways in COVID-19

COVID-19 is a highly infectious viral disease caused by the novel coronavirus SARS-CoV-2. While it was initially regarded as a strictly respiratory illness, the impact of COVID-19 on multiple organs is increasingly recognized. The brain is among the targets of COVID-19, and it can be impacted in multiple ways, both directly and indirectly. Direct brain infection by SARS-CoV-2 may occur via axonal transport via the olfactory nerve, eventually infecting the olfactory cortex and other structures in the temporal lobe, and potentially the brain stem. A hematogenous route, which involves viral crossing of blood-brain barrier, is also possible. Secondary mechanisms involve hypoxia due to respiratory failure, as well as aberrant immune response leading to various forms of encephalopathy, white matter damage, and abnormal blood clotting resulting in stroke. Multiple neurological symptoms of COVID-19 have been described. These involve anosmia/ageusia, headaches, seizures, mental confusion and delirium, and coma. There is a growing concern that in a number of patients, long-term or perhaps even permanent cognitive impairment will persist well after the recovery from acute illness. Furthermore, COVID-19 survivors may be at increased risk for developing neurodegenerative diseases years or decades later. Since COVID-19 is a new disease, it will take months or even years to characterize the exact nature, scope, and temporal extent of its long-term neurocognitive sequelae. To that end, rigorous and systematic longitudinal follow-up will be required. For this effort to succeed, appropriate protocols and patient registries should be developed and put in place without delay now.

Neurological involvement of COVID-19: from neuroinvasion and neuroimmune crosstalk to long-term consequences

As the coronavirus disease 2019 (COVID-19) pandemic continues to be a multidimensional threat to humanity, more evidence of neurological involvement associated with it has emerged. Neuroimmune interaction may prove to be important not only in the pathogenesis of neurological manifestations but also to prevent systemic hyperinflammation. In this review, we summarize reports of COVID-19 cases with neurological involvement, followed by discussion of possible routes of entry, immune responses against coronavirus infection in the central nervous system and mechanisms of nerve degeneration due to viral infection and immune responses. Possible mechanisms for neuroprotection and virus-associated neurological consequences are also discussed.

A rapid review of the pathoetiology, presentation, and management of delirium in adults with COVID-19

Background COVID-19 causes significant morbidity and mortality. Despite the high prevalence of delirium and delirium-related symptoms in COVID-19 patients, data and evidence-based recommendations on the pathophysiology and management of delirium are limited. Objective We conducted a rapid review of COVID-19-related delirium literature to provide a synthesis of literature on the prevalence, pathoetiology, and management of delirium in these patients. Methods Systematic searches of Medline, Embase, PsycInfo, LitCovid, WHO-COVID-19, and Web of Science electronic databases were conducted. Grey literature was also reviewed, including preprint servers, archives, and websites of relevant organizations. Search results were limited to the English language. We included literature focused on adults with COVID-19 and delirium. Papers were excluded if they did not mention signs or symptoms of delirium. Results 229 studies described prevalence, pathoetiology, and/or management of delirium in adults with COVID-19. Delirium was rarely assessed with validated tools. Delirium affected >50% of all patients with COVID-19 admitted to the ICU. The etiology of COVID-19 delirium is likely multifactorial, with some evidence of direct brain effect. Prevention remains the cornerstone of management in these patients. To date, there is no evidence to suggest specific pharmacological strategies. Discussion Delirium is common in COVID-19 and may manifest from both indirect and direct effects on the central nervous system. Further research is required to investigate contributing mechanisms. As there is limited empirical literature on delirium management in COVID-19, management with non-pharmacological measures and judicious use of pharmacotherapy is suggested.

Is Guillain-Barré Syndrome Associated With COVID-19 Infection? A Systemic Review of the Evidence

Background: There is emerging evidence that Guillain-Barré syndrome (GBS) may be associated with coronavirus disease 2019 (COVID-19) infection. The aim of this review was to investigate the strength of the evidence. Method: The review was registered in PROSPERO (CDR42020184822). Three electronic databases, MEDLINE, PubMed, and Web of Science, and three preprint servers, MedRvix, ChemRvix, and BioRvix, were searched from December 2019 to 24th September 2020. Studies were included if they were on COVID-19 and of any design. Articles that are reviews or opinion were excluded. The selection process was carried out using EndNote and Rayyan software. The main outcomes in the study were study design, sample size, sex, age, overall GBS symptoms, other COVID-19 symptoms, comorbidity, timing between infection and the onset of neurological symptoms, CT, MRI, and EMG results. Methodological quality of the studies was assessed using the McMaster Critical Review Form. The collected data was analyzed using qualitative synthesis. Findings: Fifty-one high-quality studies (mostly) consisting of 83 patients were included in the study. All of the patients (except in a very few) in the included studies had confirmed diagnosis of COVID-19. Similarly, the diagnosis of GBS was based on standard clinical, electrophysiological, and cerebrospinal fluid (CSF) criteria. Conclusion: GBS may be associated with COVID-19, and therefore, testing for COVID-19 is recommended in patients presenting with GBS during this pandemic.

The neuropathological impact of COVID-19: a review

BACKGROUND

The Coronavirus disease 2019 (COVID-19) outbreak has become a challenging global issue after its emergence in December 2019. Due to the high adaptation of the virus, COVID-19 demonstrated a high transmission and infectivity potentials. Several studies demonstrated that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induce deleterious neurological manifestations through interacting with the central nervous system (CNS).

MAIN BODY

The neuroinvasive potential of SARS-CoV-2 might contribute to its fatal behavior. Understanding the underlying mechanisms of this novel neuropathogen might contribute to the development of effective therapeutic strategies. The manifestations of neural damage in COVID-19 patients ranged from headache to severe encephalopathy and progression of preexisting neural disorders, it is speculated that neuroinvasion is strongly linked to the fatal respiratory dysfunction. The underlying neuropathological impact of emerging pneumonia (COVID-19) is still unclear.

CONCLUSION

This review demonstrated the urgent need to understand the neuropathology of COVID-19, to manage the current borderless viral outbreak of SARS-CoV-2 and its comorbidities. Moreover, SARS-CoV-2 could be regarded as an opportunistic neuropathogen that affects several vital functions in the human body.

Neuroinvasive potential of human coronavirus OC43: case report of fatal encephalitis in an immunocompromised host

Neurologic manifestations of COVID-19 include anosmia, ageusia, encephalopathy, agitation, confusion, ischemic strokes, Guillain–Barré syndrome, seizures, and hemorrhagic encephalitis. Although mechanisms of central nervous system (CNS) injury are likely diverse, direct viral invasion of the CNS has been demonstrated in case reports. Neurotropism of human coronaviruses (HCoVs) is therefore of great interest in the context of the COVID-19 pandemic. Here we present an autopsy-proven case of fatal human coronavirus (HCoV)-OC43 encephalitis in an infant with aplastic thymus and chronic T-cell lymphopenia. Clinicians should remain alert to the possibility of direct CNS invasion by human coronaviruses, including the novel pandemic SARS-CoV-2.

Facial palsy during the COVID-19 pandemic

OBJECTIVE

To compare the incidence and clinical features of individuals presenting in emergency rooms (ER) with facial palsy during the Italian COVID-19 outbreak and in the same period of 2019.

METHODS

We retrospectively reviewed the medical records for all accesses to the six ER in the province of Reggio Emilia, Italy, during the first phase of the COVID-19 pandemic (27 February-3 May 2020) to identify all cases of diagnosed facial palsy. Clinical information was retrieved for each patient and compared with that of facial palsy cases presenting in 2019.

RESULT

Between 27 February and 3 May 2020, 38 patients presented to provincial ERs for facial palsy; in 2019, there were 22 cases, for an incidence rate ratio of 1.73 (95% CI 1.02-2.92) for the 2020 cohort. Of the 2020 cohort, eight patients (21%) presented with active or recent symptoms consistent with COVID-19 infection, compared with 2 (9%) in 2019 (p = .299); one was tested and resulted positive for SARS-CoV-2. Moreover, patients were younger (-11 years, p = .037) than those of the previous year and manifested a longer lag (+1.1 days, p = .001) between symptoms onset and ER presentation.

CONCLUSION

We observed a higher occurrence of facial palsy during the COVID-19 outbreak compared to the same period of the previous year; 21% of patients presenting with facial palsy had active or recent symptoms consistent with SARS-CoV-2 infection, suggesting an excess risk of facial palsy during or after COVID-19. These patients searched for medical attention later, probably because of the fear of contracting COVID-19 during assistance.

Modeling SARS-CoV-2 infection in individuals with opioid use disorder with brain organoids

The COVID-19 pandemic has aggravated a preexisting epidemic: the opioid crisis. Much literature has shown that the circumstances imposed by COVID-19, such as social distancing regulations, medical and financial instability, and increased mental health issues, have been detrimental to those with opioid use disorder (OUD). In addition, unexpected neurological sequelae in COVID-19 patients suggest that COVID-19 compromises neuroimmunity, induces hypoxia, and causes respiratory depression, provoking similar effects as those caused by opioid exposure. Combined conditions of COVID-19 and OUD could lead to exacerbated complications. With limited human in vivo options to study these complications, we suggest that iPSC-derived brain organoid models may serve as a useful platform to investigate the physiological connection between COVID-19 and OUD. This mini-review highlights the advances of brain organoids in other neuropsychiatric and infectious diseases and suggests their potential utility for investigating OUD and COVID-19, respectively.

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.

Association Between Psychological Distress, Cognitive Complaints, and Neuropsychological Status After a Severe COVID-19 Episode: A Cross-Sectional Study

Background: Cognitive complaints are frequent after COVID-19 but their clinical determinants are poorly understood. This study aimed to explore the associations of objective cognitive performances and psychological distress with cognitive complaints in COVID-19 survivors. Materials and Methods: Patients previously hospitalized for COVID-19 in a university hospital during the first wave of COVID-19 pandemic in France were followed-up at 1 month after their admission. Cognitive complaints were self-reported and standardized instruments were used to assess neuropsychological status (Digit Symbol Substitution Test, Semantic Verbal Fluency Test, Mini Mental Status Examination) and psychological distress (Hospital Anxiety and Depression Scale, HADS). Multivariable analyses were adjusted for age, sex, admission in intensive care unit (ICU) and need for oxygen and C-reactive protein. Results: One hundred patients (34% women, median age: 60 years [interquartile range: 49-72)] completed the neuropsychological assessment at follow-up. In multivariable analyses, cognitive complaints at 1-month were associated with greater HADS score (OR for one interquartile range: OR: 1.96, 95% CI: 1.08-3.57) and older age (OR: 1.05, 95% CI: 1.01-1.09) and, negatively, with admission in ICU (OR: 0.22, 95% CI: 0.05-0.90). In contrast, none of the objective neuropsychological test scores was significantly associated with cognitive complaints. Exploratory analysis showed that cognitive complaints were associated with both anxiety and depressive symptoms. Discussion: These preliminary results suggest that cognitive complaints at 1 month after a hospitalization for COVID-19 are associated with psychological distress, independently of objective neuropsychological status. Anxiety and depression symptoms should be systematically screened in patients presenting with cognitive complaints after a severe COVID-19 episode.

Prevalence of Mental Health Problems and Its Associated Factors Among Recovered COVID-19 Patients During the Pandemic: A Single-Center Study

Introduction: The coronavirus disease 2019 (COVID-19), is profoundly affecting the mental health status. Although the burden of mental health problems has been reported in the general population and health care workers, little is known about the prevalence of mental health disorders among recovered COVID-19 patients and their associated factors. Methods: A cross-sectional telephonic-study of recovered COVID-19 patients with and without a history of hospitalization was conducted from April 20 to June 20, 2020, in Tehran, Iran. We assessed the anxiety symptoms, depression, and post-traumatic stress disorder (PTSD) among participants, using the Patient Health Questionnaire (PHQ-4) and PTSD checklist for DSM-5 (PCL-5). Logistic regression analyses were used to explore the risk factors associated with mental health problems. Results: A total of 602 individuals with a mean age of 53.2 years (SD: 14.7), completed the study. The rates of mental health symptoms among the respondents were 5.8% (95% CI: 4.2-7.8%) for anxiety, 5.0% (95% CI: 3.5-7.0%) for depression, and 3.8% (95% CI: 2.3-5.3%) for PTSD disorders. Moreover, being younger than 50 years and female gender was significantly associated with a higher probability of reporting anxiety (p < 0.01), and depression (p < 0.001 for being younger than 50 years, p < 0.02 for female gender). Conclusions: The current study indicated that patients with COVID-19 presented features of anxiety, depression, and PTSD. These results may help implement appropriate mental health intervention policies for those at risk and minimize the mental health consequences of the COVID-19.

Case Report: Acute Spinal Cord Myelopathy in Patients With COVID-19

COVID-19 is typically associated with fever and severe respiratory symptoms including dry cough and dyspnea. However, COVID-19 may also affect both central and peripheral nervous systems. To date, the incidence rate of spinal cord involvement in COVID-19 is not known and the pathogenesis is still not fully understood. We report here two female patients admitted to Assiut University Hospitals/Egypt during the period from first of July to August 10, 2020. Both presented with a positive SARS-CoV-2 polymerase chain reaction (PCR) nasopharyngeal swab, elevated serum d-dimer and ferritin levels, and bilateral ground glass appearance in a CT chest scan. The first was a 60-year-old female with acute onset of flaccid paraplegia 10 days after flu-like symptoms, in whom MRI revealed transverse myelitis. The second was a 21-year-old female with symptoms of acute quadriplegia, fever, headache, and anosmia in whom an MRI scan revealed long cervico-thoracic myelopathy. Anterior spinal artery occlusion and possibly transverse myelitis were considered as differential diagnosis of long segment myelopathy.

The Leukotriene Receptor Antagonist Montelukast as a Potential COVID-19 Therapeutic

The emergence and global impact of COVID-19 has focused the scientific and medical community on the pivotal influential role of respiratory viruses as causes of severe pneumonia, on the understanding of the underlying pathomechanisms, and on potential treatment for COVID-19. The latter concentrates on four different strategies: (i) antiviral treatments to limit the entry of the virus into the cell and its propagation, (ii) anti-inflammatory treatment to reduce the impact of COVID-19 associated inflammation and cytokine storm, (iii) treatment using cardiovascular medication to reduce COVID-19 associated thrombosis and vascular damage, and (iv) treatment to reduce the COVID-19 associated lung injury. Ideally, effective COVID-19 treatment should target as many of these mechanisms as possible arguing for the search of common denominators as potential drug targets. Leukotrienes and their receptors qualify as such targets: they are lipid mediators of inflammation and tissue damage and well-established targets in respiratory diseases like asthma. Besides their role in inflammation, they are involved in various other aspects of lung pathologies like vascular damage, thrombosis, and fibrotic response, in brain and retinal damages, and in cardiovascular disease. In consequence, leukotriene receptor antagonists might be potential candidates for COVID-19 therapeutics. This review summarizes the current knowledge on the potential involvement of leukotrienes in COVID-19, and the rational for the use of the leukotriene receptor antagonist montelukast as a COVID-19 therapeutic.

An Unusual Case of COVID-19 Presenting as Acute Psychosis

PURPOSE

To report a case of COVID-19 presenting with acute psychosis, without the hallmark respiratory symptoms of fever, cough, and shortness of breath associated with the novel virus.

CASE SUMMARY

A 58 year-old male presented with acute psychosis and no symptoms associated with COVID-19. He denied fever, chills, chest pain, shortness of breath, or gastrointestinal symptoms. The patient had a medical history of coronary artery disease, chronic hepatitis C, polysubstance abuse (including cocaine and alcohol), liver disease, anxiety, and panic disorder. Patient was confused, disruptive, unable to communicate, and admitted to hallucinations. Prior to transfer to a psychiatric facility, the patient developed a cough, triggering COVID-19 testing and a positive result. He was initially treated with hydroxychloroquine before this was discontinued. The patient was treated with haloperidol and lorazepam before returning to baseline. He was discharged home with continued isolation.

CONCLUSION

Acute psychosis, with or without other symptoms, appears to be a potential presentation of COVID-19 and should be considered by clinicians as a possible presenting manifestation. Other coronaviruses appear to have also been linked to neurological manifestations, including psychosis. Neurological manifestations of the virus vary widely, but have been reported multiple times. Treatment, as shown in this case report, appears to be supportive and symptom based for the associated psychotic symptoms. Optimal antiviral treatment is still yet to be clearly defined, as research continues on how to best treat the virus itself.

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 D614 and G614 spike variants impair neuronal synapses and exhibit differential fusion ability.. [PMID: 0 DOI: 10.1101/2020.12.03.409763]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes Coronavirus disease 2019 (COVID-19) exhibits two major variants based on mutations of its spike protein, i.e., the D614 prototype and G614 variant. Although neurological symptoms have been frequently reported in patients, it is still unclear whether SARS-CoV-2 impairs neuronal activity or function. Here, we show that expression of both D614 and G614 spike proteins is sufficient to induce phenotypes of impaired neuronal morphology, including defective dendritic spines and shortened dendritic length. Using spike protein-specific monoclonal antibodies, we found that D614 and G614 spike proteins show differential S1/S2 cleavage and cell fusion efficiency. Our findings provide an explanation for higher transmission of the G614 variant and the neurological manifestations observed in COVID-19 patients.

Actualización de la Declaración de consenso en medicina critica para la atención multidisciplinaria del paciente con sospecha o confirmación diagnóstica de COVID-19

Antecedentes y objetivos

La enfermedad por coronavirus de 2019 (COVID-19) es una enfermedad ocasionada por el nuevo coronavirus del síndrome respiratorio agudo grave (SARS-CoV-2). Se identificó por primera vez en diciembre de 2019 en la ciudad de Wuhan, en los meses siguientes se expandió rápidamente a todos los continentes y la Organización Mundial de la Salud (OMS) la reconoció como una pandemia global el 11 de marzo de 2020. La mayoría de los individuos son asintomáticos pero una baja proporción ingresan a cuidados intensivos con una alta morbimortalidad. Este consenso tiene como objetivo actualizar la declaratoria inicial emitida por la Asociación Colombiana de Medicina Crítica (AMCI) para el manejo del paciente críticamente enfermo con COVID-19, dentro de las áreas críticas de las instituciones de salud.

Métodos

Este estudio utilizó dos técnicas de consenso formal para construir las recomendaciones finales: Delphi modificada y grupos nominales. Se construyeron preguntas por la estrategia PICO. 10 grupos nominales desarrollaron recomendaciones para cada unidad temática. El producto del consenso fue evaluado y calificado en una ronda Delphi y se discutió de forma virtual por los relatores de cada núcleo y los representantes de sociedades médicas científicas afines al manejo del paciente con COVID-19.

Resultados

80 expertos nacionales participaron en la actualización del consenso AMCI, especialistas en Medicina Critica y Cuidados Intensivos, Nefrología, Neurología, Neumología, bioeticistas, Medicina interna, Anestesia, Cirugía General, Cirugía de cabeza y cuello, Cuidados Paliativos, Enfermeras Especialistas en Medicina crítica, Terapeutas respiratorias especialistas en medicina crítica y Fisioterapia, con experiencia clínica en la atención del paciente críticamente enfermo. La declaratoria emite recomendaciones en los ámbitos más relevantes para la atención en salud de los casos de COVID-19, al interior de las unidades de cuidados intensivos, en el contexto nacional de Colombia.

Conclusiones

Un grupo significativo multidisciplinario de profesionales expertos en medicina crítica emiten, mediante técnicas de consenso formal, recomendaciones sobre la mejor práctica para la atención del paciente críticamente enfermo con COVID-19. Las recomendaciones deben ser adaptadas a las condiciones específicas, administrativas y estructurales de las distintas unidades de cuidados intensivos del país.

Retrospective Observational Study of Brain MRI Findings in Patients with Acute SARS-CoV-2 Infection and Neurologic Manifestations

Background This study provides a detailed imaging assessment in a large series of patients infected with coronavirus disease 2019 (COVID-19) and presenting with neurologic manifestations. Purpose To review the MRI findings associated with acute neurologic manifestations in patients with COVID-19. Materials and Methods This was a cross-sectional study conducted between March 23 and May 7, 2020, at the Pitié-Salpêtrière Hospital, a reference center for COVID-19 in the Paris area. Adult patients were included if they had a diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with acute neurologic manifestations and referral for brain MRI. Patients with a prior history of neurologic disease were excluded. The characteristics and frequency of different MRI features were investigated. The findings were analyzed separately in patients in intensive care units (ICUs) and other departments (non-ICU). Results During the inclusion period, 1176 patients suspected of having COVID-19 were hospitalized. Of 308 patients with acute neurologic symptoms, 73 met the inclusion criteria and were included (23.7%): thirty-five patients were in the ICU (47.9%) and 38 were not (52.1%). The mean age was 58.5 years ± 15.6 [standard deviation], with a male predominance (65.8% vs 34.2%). Forty-three patients had abnormal MRI findings 2-4 weeks after symptom onset (58.9%), including 17 with acute ischemic infarct (23.3%), one with a deep venous thrombosis (1.4%), eight with multiple microhemorrhages (11.3%), 22 with perfusion abnormalities (47.7%), and three with restricted diffusion foci within the corpus callosum consistent with cytotoxic lesions of the corpus callosum (4.1%). Multifocal white matter-enhancing lesions were seen in four patients in the ICU (5%). Basal ganglia abnormalities were seen in four other patients (5%). Cerebrospinal fluid analyses were negative for SARS-CoV-2 in all patients tested (n = 39). Conclusion In addition to cerebrovascular lesions, perfusion abnormalities, cytotoxic lesions of the corpus callosum, and intensive care unit-related complications, we identified two patterns including white matter-enhancing lesions and basal ganglia abnormalities that could be related to severe acute respiratory syndrome coronavirus 2 infection. © RSNA, 2020 Online supplemental material is available for this article.

Involvement of the nervous system in COVID-19: The bell should toll in the brain

The world is fuming at SARS-CoV-2 for being the culprit for causing the devastating COVID-19, claiming millions of lives across the globe in the form of respiratory disorders. But lesser known are its effects on the CNS that are slowly surfacing in the worldwide population. Our review illustrates findings that claim SARS-CoV-2's arrival onto the ACE2 receptors of neuronal and glial cells mainly via CSF, olfactory nerve, trigeminal nerve, neuronal dissemination, and hematogenous pathways. The role of SARS-CoV-2 structural proteins in its smooth viral infectivity of the host cannot be ignored, especially the spike proteins that mediate spike attachment and host membrane fusion. Worth mentioning the nucleocapsid, envelope, and membrane proteins make the proliferation of SARS-CoV-2 much simpler than expected in spreading infection. This has led to catastrophic conditions like seizures, Guillain-Barré syndrome, viral encephalitis, meningoencephalitis, acute cerebrovascular disease, and respiratory failures. Placing a magnifying lens on the lesser-explored CNS consequences of COVID-19, we attempt to shift the focus of our readers onto the new supporting threats to which further studies are needed.

The SARS-CoV-2 spike protein alters barrier function in 2D static and 3D microfluidic in-vitro models of the human blood-brain barrier

As researchers across the globe have focused their attention on understanding SARS-CoV-2, the picture that is emerging is that of a virus that has serious effects on the vasculature in multiple organ systems including the cerebral vasculature. Observed effects on the central nervous system include neurological symptoms (headache, nausea, dizziness), fatal microclot formation and in rare cases encephalitis. However, our understanding of how the virus causes these mild to severe neurological symptoms and how the cerebral vasculature is impacted remains unclear. Thus, the results presented in this report explored whether deleterious outcomes from the SARS-CoV-2 viral spike protein on primary human brain microvascular endothelial cells (hBMVECs) could be observed. The spike protein, which plays a key role in receptor recognition, is formed by the S1 subunit containing a receptor binding domain (RBD) and the S2 subunit. First, using postmortem brain tissue, we show that the angiotensin converting enzyme 2 or ACE2 (a known binding target for the SARS-CoV-2 spike protein), is ubiquitously expressed throughout various vessel calibers in the frontal cortex. Moreover, ACE2 expression was upregulated in cases of hypertension and dementia. ACE2 was also detectable in primary hBMVECs maintained under cell culture conditions. Analysis of cell viability revealed that neither the S1, S2 or a truncated form of the S1 containing only the RBD had minimal effects on hBMVEC viability within a 48 h exposure window. Introduction of spike proteins to invitro models of the blood-brain barrier (BBB) showed significant changes to barrier properties. Key to our findings is the demonstration that S1 promotes loss of barrier integrity in an advanced 3D microfluidic model of the human BBB, a platform that more closely resembles the physiological conditions at this CNS interface. Evidence provided suggests that the SARS-CoV-2 spike proteins trigger a pro-inflammatory response on brain endothelial cells that may contribute to an altered state of BBB function. Together, these results are the first to show the direct impact that the SARS-CoV-2 spike protein could have on brain endothelial cells; thereby offering a plausible explanation for the neurological consequences seen in COVID-19 patients.

Neurotropism of SARS-CoV-2 and its neuropathological alterations: Similarities with other coronaviruses

A novel coronavirus (SARS-CoV-2) emerged from Wuhan, China, and spread quickly around the world. In addition to fever, cough and shortness of breath, it was confirmed that the patients also have manifestations towards the central nervous system (CNS), especially those critically ill ones. In this review, we will discuss how SARS-CoV-2 gain access to the CNS and the possible consequences. Both SARS-CoV-2 and SARS-CoV-1 in 2002 share the same receptor angiotensin-converting enzyme 2 (ACE2), which can be found in the brain and mediate the disease process. Both direct attack of SARS-CoV-2 and the abnormal immune response in the CNS would contribute to the disease. Also, there is a relationship between SARS-CoV-2 and the occurrence of acute cerebrovascular diseases.

Environmental Nanoparticles, SARS-CoV-2 Brain Involvement, and Potential Acceleration of Alzheimer's and Parkinson's Diseases in Young Urbanites Exposed to Air Pollution

Alzheimer's and Parkinson's diseases (AD, PD) have a pediatric and young adult onset in Metropolitan Mexico City (MMC). The SARS-CoV-2 neurotropic RNA virus is triggering neurological complications and deep concern regarding acceleration of neuroinflammatory and neurodegenerative processes already in progress. This review, based on our MMC experience, will discuss two major issues: 1) why residents chronically exposed to air pollution are likely to be more susceptible to SARS-CoV-2 systemic and brain effects and 2) why young people with AD and PD already in progress will accelerate neurodegenerative processes. Secondary mental consequences of social distancing and isolation, fear, financial insecurity, violence, poor health support, and lack of understanding of the complex crisis are expected in MMC residents infected or free of SARS-CoV-2. MMC residents with pre-SARS-CoV-2 accumulation of misfolded proteins diagnostic of AD and PD and metal-rich, magnetic nanoparticles damaging key neural organelles are an ideal host for neurotropic SARS-CoV-2 RNA virus invading the body through the same portals damaged by nanoparticles: nasal olfactory epithelium, the gastrointestinal tract, and the alveolar-capillary portal. We urgently need MMC multicenter retrospective-prospective neurological and psychiatric population follow-up and intervention strategies in place in case of acceleration of neurodegenerative processes, increased risk of suicide, and mental disease worsening. Identification of vulnerable populations and continuous effort to lower air pollution ought to be critical steps.

Delayed Symptoms in Patients Recovered from COVID-19

Background:

COVID-19 is a new disease, so we don’t know what comes next. Since information on delayed symptoms is limited, this study was conducted to assess the frequency of delayed symptoms in patients with COVID-19.

Methods:

This follow-up cross-sectional study was conducted in a referral general hospital in Tehran, Iran from Feb to Apr 2020. Two hundred patients hospitalized for COVID-19 and were discharged were assessed for delayed symptoms 6 wk after discharge.

Results:

The mean age of the participants was 55.58±13.52, and 160 (80%) Of them were male. On admission to hospital, patients reported a mean of 5.63±2.88 symptoms per patient, range from 1 to 14 symptoms. Dyspnea was seen in 119 (59.5%) 0f them as the most frequent symptom. Then weakness, myalgia, and shivering were reported with a frequency of 111 (55.5%), 107 (53.5%), and 103 (51.5%), respectively. Six weeks after discharge reassessment was done. None of the patients was readmitted to the hospital. Ninety-four (42%) of them were symptom-free. Fatigue was the most frequent delayed symptom with a frequency of 39 (19.5%), and then dyspnea, weakness, and activity intolerance with a frequency of 37 (18.5%), 36 (18%), and 29 (14.5%) were reported, respectively.

Conclusion:

Fatigue, dyspnea, weakness, anxiety, and activity intolerance were most frequent delayed symptoms, respectively. Majority of patient was symptoms free and those with symptom, had mild to moderate symptoms. The importance of symptoms is not fully recognized. Follow up clinics and in some cases rehabilitation programs may be helpful.

COVID-19-Associated Guillain-Barre Syndrome: Atypical Para-infectious Profile, Symptom Overlap, and Increased Risk of Severe Neurological Complications

The concurrence of COVID-19 with Guillain-Barre syndrome (GBS) can increase the likelihood of neuromuscular respiratory failure, autonomic dysfunction, and other life-threatening symptoms. Currently, very little is known about the underlying mechanisms, clinical course, and prognostic implications of comorbid COVID-19 in patients with GBS. We reviewed COVID-19-associated GBS case reports published since the outbreak of the pandemic, with a database search up to August 2020, including a manual search of the reference lists for additional relevant cases. Fifty-one (51) case reports of COVID-19 patients (aged 23–84 years) diagnosed with GBS in 11 different countries were included in this review. The results revealed atypical manifestations of GBS, including para-infectious profiles and onset of GBS without antecedent COVID-19 symptoms. Although all tested patients had signs of neuroinflammation, none had SARS-CoV-2 in the cerebrospinal fluid (CSF), and only four (4) patients had antiganglioside antibodies. The majority had a 1- to 10-day time interval between the onset of COVID-19 and GBS symptoms, and many had a poor outcome, with 20 out of the 51 (39.2%) requiring mechanical ventilation, and two deaths within 12 to 24 h. The atypical manifestations of COVID-19-associated GBS, especially the para-infectious profile and short time interval between the onset of the COVID-19 and GBS symptoms, increase the likelihood of symptom overlap, which can complicate the treatment and result in worsened disease progression and/or higher mortality rates. Inclusion of a neurological assessment during diagnosis of COVID-19 might facilitate timely identification and effective management of the GBS symptoms and improve treatment outcome.

An Example of a Stroke Unit Reshaping in the Context of a Regional Hub and Spoke System in the COVID-19 Era

During the COVID-19 outbreak, the Neurology and Stroke Unit (SU) of the hospital of Varese had to serve as a cerebrovascular hub, meaning that the referral area for the unit doubled. The number of beds in the SU was increased from 4 to 8. We took advantage of the temporary suspension of the out-patient clinic and reshaped our activity to guarantee the 24/7 availability of recombinant tissue Plasminogen Activator (rtPA) intravenous therapy (IVT) in the SU, and to ensure we were able to admit patients to the SU as soon as they completed endovascular treatment (EVT). In 42 days, 46 stroke patients were admitted to our hospital, and 34.7% of them underwent IVT and/or EVT, which means that we treated 0.38 patients per day; in the baseline period from 2016 to 2018, these same figures had been 23.5% and 0.23, respectively. The mean values of the door-to-first CT/MRI and the door-to-groin puncture, but not of the onset-to-door and the door-to-needle periods were slightly but significantly longer than those observed in the baseline period in 276 patients. On an individual basis, only one patient exceeded the door-to-groin puncture time limit computed from the baseline period by about 10 min. None of the patients had a major complication following the procedures. None of the patients was or became SARS-CoV2 positive. In conclusion, we were able to manage the new hub-and-spoke system safely and without significant delays. The reshaping of the SU was made possible by the significant reduction of out-patient activity. The consequences of this reduction are still unknown but eventually, this emergency will suggest ways to reconsider the management and the allocation of health system resources.

Cell Clearing Systems as Targets of Polyphenols in Viral Infections: Potential Implications for COVID-19 Pathogenesis

The novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated the ongoing coronavirus disease-2019 (COVID-19) pandemic, still with an uncertain outcome. Besides pneumonia and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), other features became evident in the context of COVID-19. These includes endothelial and coagulation dysfunction with disseminated intravascular coagulation (DIC), and multiple organ dysfunction syndrome (MODS), along with the occurrence of neurological alterations. The multi-system nature of such viral infection is a witness to the exploitation and impairment of ubiquitous subcellular and metabolic pathways for the sake of its life-cycle, ranging from host cell invasion, replication, transmission, up to a cytopathic effect and overt systemic inflammation. In this frame, alterations in cell-clearing systems of the host are emerging as a hallmark in the pathogenesis of various respiratory viruses, including SARS-CoV-2. Indeed, exploitation of the autophagy and proteasome pathways might contribute not only to the replication of the virus at the site of infection but also to the spreading of either mature virions or inflammatory mediators at both cellular and multisystem levels. In this frame, besides a pharmacological therapy, many researchers are wondering if some non-pharmacological substances might counteract or positively modulate the course of the infection. The pharmacological properties of natural compounds have gained increasing attention in the field of alternative and adjunct therapeutic approaches to several diseases. In particular, several naturally-occurring herbal compounds (mostly polyphenols) are reported to produce widespread antiviral, anti-inflammatory, and anti-oxidant effects while acting as autophagy and (immuno)-proteasome modulators. This article attempts to bridge the perturbation of autophagy and proteasome pathways with the potentially beneficial effects of specific phytochemicals and flavonoids in viral infections, with a focus on the multisystem SARS-CoV-2 infection.

COVID-19 and Cerebrovascular Diseases: A Systematic Review and Perspectives for Stroke Management

Importance: Reported cerebrovascular events in patients with COVID-19 are mainly ischemic, but hemorrhagic strokes and cerebral venous sinus thrombosis (CSVT), especially in critically ill patients, have also been described. To date, it is still not clear whether cerebrovascular manifestations are caused by direct viral action or indirect action mediated by inflammatory hyperactivation, and in some cases, the association may be casual rather than causal. Objective: To conduct a systematic review on the cerebrovascular events in COVID-19 infection. Evidence review: A comprehensive literature search on PubMed was performed including articles published from January 1, 2020, to July 23, 2020, using a suitable keyword strategy. Additional sources were added by the authors by reviewing related references. The systematic review was conducted in accordance with the PRISMA guidelines. Only articles reporting individual data on stroke mechanism and etiology, sex, age, past cardiovascular risk factors, COVID symptoms, admission NIHSS, D-dimer levels, and acute stroke treatment were selected for the review. Articles that did not report the clinical description of the cases were excluded. A descriptive statistical analysis of the data collected was performed. Finding: From a total of 1,210 articles published from January 1, 2020, to July 23, 2020, 80 articles (275 patients), which satisfied the abovementioned criteria, were included in this review. A total of 226 cases of ischemic stroke (IS), 35 cases of intracranial bleeding, and 14 cases of CVST were found. Among patients with IS, the mean age was 64.16 ±14.73 years (range 27-92 years) and 53.5% were male. The mean NIHSS score reported at the onset of stroke was 15.23 ±9.72 (range 0-40). Primary endovascular thrombectomy (EVT) was performed in 24/168 patients (14.29%), intravenous thrombolysis (IVT) was performed in 17/168 patients (10.12%), and combined IVT+EVT was performed in 11/168 patients (6.55%). According to the reported presence of large vessel occlusion (LVO) (105 patients), 31 patients (29.52%) underwent primary EVT or bridging. Acute intracranial bleeding was reported in 35 patients: 24 patients (68.57%) had intracerebral hemorrhage (ICH), 4 patients (11.43%) had non-traumatic subarachnoid hemorrhage (SAH), and the remaining 7 patients (20%) had the simultaneous presence of SAH and ICH. Fourteen cases of CVST were reported in the literature (50% males), mean age 42.8 years ±15.47 (range 23-72). Treatment was reported only in nine patients; seven were treated with anticoagulant therapy; one with acetazolamide, and one underwent venous mechanical thrombectomy. Conclusion: Cerebrovascular events are relatively common findings in COVID-19 infection, and they could have a multifactorial etiology. More accurate and prospective data are needed to better understand the impact of cerebrovascular events in COVID-19 infection.

Assessment of neurological manifestations in hospitalized patients with COVID-19

BACKGROUND AND PURPOSE

The objective of this study was to assess the neurological manifestations in a series of consecutive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive patients, comparing their frequency with a population hospitalized in the same period for flu/respiratory symptoms, finally not related to SARS-CoV-2.

METHODS

Patients with flu/respiratory symptoms admitted to Fondazione Policlinico Gemelli hospital from 14 March 2020 to 20 April 2020 were retrospectively enrolled. The frequency of neurological manifestations of patients with SARS-CoV-2 infection was compared with a control group.

RESULTS

In all, 213 patients were found to be positive for SARS-CoV-2, after reverse transcriptase polymerase chain reaction on nasal or throat swabs, whilst 218 patients were found to be negative and were used as a control group. Regarding central nervous system manifestations, in SARS-CoV-2-positive patients a higher frequency of headache, hyposmia and encephalopathy always related to systemic conditions (fever or hypoxia) was observed. Furthermore, muscular involvement was more frequent in SARS-CoV-2 infection.

CONCLUSIONS

Patients with COVID-19 commonly have neurological manifestations but only hyposmia and muscle involvement seem more frequent compared with other flu diseases.

COVID-19 and its impact on neurological manifestations and mental health: the present scenario

Though the COVID-19 pandemic primarily affects pulmonary and cardiorenal functions, many healthcare and its allied groups reported neurological involvement of SARS-CoV-2 in combination with either pre-existing metabolic abnormalities, medical conditions, infections or even chronic to acute inflammatory episodes of the nervous system. The present review provides a fair outlook of the published literature and also the case reports with an emphasis on plausible mechanisms involved in neurological complications of the central and peripheral nervous systems. Awareness on the neuropsychiatric manifestations being discussed in this article should ideally help the medical community in early identification and effective management of potentially life-threatening neurological diseases.

Neuromuscular presentations in patients with COVID-19

COVID-19 is caused by the coronavirus SARS-CoV-2 that has an affinity for neural tissue. There are reports of encephalitis, encephalopathy, cranial neuropathy, Guillain-Barrè syndrome, and myositis/rhabdomyolysis in patients with COVID-19. In this review, we focused on the neuromuscular manifestations of SARS-CoV-2 infection. We analyzed all published reports on SARS-CoV-2-related peripheral nerve, neuromuscular junction, muscle, and cranial nerve disorders. Olfactory and gustatory dysfunction is now accepted as an early manifestation of COVID-19 infection. Inflammation, edema, and axonal damage of olfactory bulb have been shown in autopsy of patients who died of COVID-19. Olfactory pathway is suggested as a portal of entry of SARS-CoV-2 in the brain. Similar to involvement of olfactory bulb, isolated oculomotor, trochlear and facial nerve has been described. Increasing reports Guillain-Barrè syndrome secondary to COVID-19 are being published. Unlike typical GBS, most of COVID-19-related GBS were elderly, had concomitant pneumonia or ARDS, more prevalent demyelinating neuropathy, and relatively poor outcome. Myalgia is described among the common symptoms of COVID-19 after fever, cough, and sore throat. Duration of myalgia may be related to the severity of COVID-19 disease. Few patients had muscle weakness and elevated creatine kinase along with elevated levels of acute-phase reactants. All these patients with myositis/rhabdomyolysis had severe respiratory complications related to COVID-19. A handful of patients with myasthenia gravis showed exacerbation of their disease after acquiring COVID-19 disease. Most of these patients recovered with either intravenous immunoglobulins or steroids.

Effects of the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV) on the nervous system. What can we expect from SARS -CoV-2?

Coronaviruses cause respiratory and gastrointestinal disorders in animals and humans. The current SARS-CoV-2, the COVID-19 infectious agent, belongs to a subgroup called betacoronavirus including the SARS-CoV and MERS-CoV responsible for epidemics in 2002 and 2012, respectively. These viruses can also infect the nervous system due to their affinity for the human angiotensin-converting enzyme 2 (ACE2) expressed in neurons and glial cells. Infections with SARS-CoV, MERS-CoV, and now SARS-CoV-2 also produce neurological signs such as acute cerebrovascular disease, impaired consciousness, and muscle injury, as well as dizziness, hypogeusia, hyposmia, hypoxia, neuralgia, and hypoxic encephalopathy. For this reason, close attention should be paid to the neurological manifestations of COVID-19 patients.

Anti-COVID-19 drug screening: Frontier concepts and core technologies

The outbreak of COVID-19 has recently evolved into a global pandemic. Up to July 2020, almost every country has confirmed COVID-19 cases reported worldwide. Many leading experts have predicted that the epidemic will persist for relatively a long period of time. Thus far, there have been no remedies proven effective against the disease. As the nation where COVID-19 broke out first, China has adopted a combination of traditional Chinese medicine and western medicine to fight against the disease, and has achieved significant clinical result. Up to now, the COVID-19 pandemic has been effectively controlled in China. However, the rest of the world (except for a limited number of countries and regions) is still in deep water. This paper thoroughly summarizes interdisciplinary notions and techniques, including disease model, biochip, network pharmacology, and molecular docking technology, etc., providing a reference for researchers in the screening of drugs for COVID-19 prevention and treatment. These methodologies may facilitate researchers to screen out more potential drugs for treating COVID-19 pneumonia and to tackle this global crisis.

COVID-19-Induced Neurovascular Injury: a Case Series with Emphasis on Pathophysiological Mechanisms

Coronavirus disease 2019 (COVID-19) is associated with a high inflammatory burden that can induce severe respiratory disease among other complications; vascular and neurological damage has emerged as a key threat to COVID-19 patients. Risk of severe infection and mortality increases with age, male sex, and comorbidities including cardiovascular disease, hypertension, obesity, diabetes, and chronic pulmonary disease. We review clinical and neuroradiological findings in five patients with COVID-19 who suffered severe neurological disease and illustrate the pathological findings in a 7-year-old boy with COVID-19-induced encephalopathy whose brain tissue sample showed angiocentric mixed mononuclear inflammatory infiltrate. We summarize the structural and functional properties of the virus including the molecular processes that govern the binding to its membrane receptors and cellular entry. In addition, we review clinical and experimental evidence in patients and animal models that suggests coronaviruses enter into the central nervous system (CNS), either via the olfactory bulb or through hematogenous spread. We discuss suspected pathophysiological mechanisms including direct cellular infection and associated recruitment of immune cells and neurovirulence, at least in part, mediated by cytokine secretion. Moreover, contributing to the vascular and neurological injury, coagulopathic disorders play an important pathogenic role. We survey the molecular events that contribute to the thrombotic microangiopathy. We describe the neurological complications associated with COVID-19 with a focus on the potential mechanisms of neurovascular injury. Our thesis is that following infection, three main pathophysiological processes-inflammation, thrombosis, and vascular injury-are responsible for the neurological damage and diverse pathology seen in COVID-19 patients.

Anosmia: a missing link in the neuroimmunology of coronavirus disease 2019 (COVID-19)

Just before 2020 began, a novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), brought for humans a potentially fatal disease known as coronavirus disease 2019 (COVID-19). The world has thoroughly been affected by COVID-19, while there has been little progress towards understanding the pathogenesis of COVID-19. Patients with a severe phenotype of disease and those who died from the disease have shown hyperinflammation and were more likely to develop neurological manifestations, linking the clinical disease with neuroimmunological features. Anosmia frequently occurs early in the course of COVID-19. The prevalence of anosmia would be influenced by self-diagnosis as well as self-misdiagnosis in patients with COVID-19. Despite this, the association between anosmia and COVID-19 has been a hope for research, aiming to understand the pathogenesis of COVID-19. Studies have suggested differently probable mechanisms for the development of anosmia in COVID-19, including olfactory cleft syndrome, postviral anosmia syndrome, cytokine storm, direct damage of olfactory sensory neurons, and impairment of the olfactory perception center in the brain. Thus, the observation of anosmia would direct us to find the pathogenesis of COVID-19 in the central nervous system, and this is consistent with numerous neurological manifestations related to COVID-19. Like other neurotropic viruses, SARS-CoV-2 might be able to enter the central nervous system via the olfactory epithelium and induce innate immune responses at the site of entry. Viral replication in the nonneural olfactory cells indirectly causes damage to the olfactory receptor nerves, and as a consequence, anosmia occurs. Further studies are required to investigate the neuroimmunology of COVID-19 in relation to anosmia.

Residual clinical damage after COVID-19: A retrospective and prospective observational cohort study

Data on residual clinical damage after Coronavirus disease-2019 (COVID-19) are lacking. The aims of this study were to investigate whether COVID-19 leaves behind residual dysfunction, and identify patients who might benefit from post-discharge monitoring. All patients aged ≥18 years admitted to the Emergency Department (ED) for COVID-19, and evaluated at post-discharge follow-up between 7 April and 7 May, 2020, were enrolled. Primary outcome was need of follow-up, defined as the presence at follow-up of at least one among: respiratory rate (RR) >20 breaths/min, uncontrolled blood pressure (BP) requiring therapeutic change, moderate to very severe dyspnoea, malnutrition, or new-onset cognitive impairment, according to validated scores. Post-traumatic stress disorder (PTSD) served as secondary outcome. 185 patients were included. Median [interquartile range] time from hospital discharge to follow-up was 23 [20-29] days. 109 (58.9%) patients needed follow-up. At follow-up evaluation, 58 (31.3%) patients were dyspnoeic, 41 (22.2%) tachypnoeic, 10 (5.4%) malnourished, 106 (57.3%) at risk for malnutrition. Forty (21.6%) patients had uncontrolled BP requiring therapeutic change, and 47 (25.4%) new-onset cognitive impairment. PTSD was observed in 41 (22.2%) patients. At regression tree analysis, the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) and body mass index (BMI) at ED presentation, and age emerged as independent predictors of the need of follow-up. Patients with PaO2/FiO2 <324 and BMI ≥33 Kg/m2 had the highest odds to require follow-up. Among hospitalised patients, age ≥63 years, or age <63 plus non-invasive ventilation or diabetes identified those with the highest probability to need follow-up. PTSD was independently predicted by female gender and hospitalisation, the latter being protective (odds ratio, OR, 4.03, 95% confidence interval, CI, 1.76 to 9.47, p 0.0011; OR 0.37, 95% CI 0.14 to 0.92, p 0.033, respectively). COVID-19 leaves behind physical and psychological dysfunctions. Follow-up programmes should be implemented for selected patients.