Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the neuroendocrine stress axis

Cognitive dysfunctions in the course of SARS‑CoV‑2 virus infection, including NeuroCOVID, frontal syndrome and cytokine storm (Review)

During the coronavirus disease 2019 (COVID-19) pandemic, cognitive impairment of varying degrees of severity began to be observed in a significant percentage of patients. The present study discussed the impact of immunological processes on structural and functional changes in the central nervous system and the related cognitive disorders. The purpose of the present review was to analyse and discuss available information from the scientific literature considering the possible relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral infection and cognitive impairment, including NeuroCOVID, frontal syndrome and cytokine storm. A systematic literature review was conducted using: Google Scholar, Elsevier and the PubMed database. When searching for materials, the following keywords were used: 'cognitive dysfunctions', 'SARS-CoV-2', 'COVID-19', 'Neuro-SARS2', 'NeuroCOVID', 'frontal syndrome', 'cytokine storm', 'Long COVID-19'. A total of 96 articles were included in the study. The analysis focused on the characteristics of each study's materials, methods, results and conclusions. SARS-CoV-2 infection may induce or influence existing cognitive disorders of various nature and severity. The influence of immunological factors related to the response against SARS-CoV-2 on the disturbance of cerebral perfusion, the functioning of nerve cells and the neuroprotective effect has been demonstrated. Particular importance is attached to the cytokine storm and the related difference between pro- and anti-inflammatory effects, oxidative stress, disturbances in the regulation of the hypothalamic-pituitary-adrenal axis and the stress response of the body.

Role of SARS-CoV-2 Spike-Protein-Induced Activation of Microglia and Mast Cells in the Pathogenesis of Neuro-COVID

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). About 45% of COVID-19 patients experience several symptoms a few months after the initial infection and develop post-acute sequelae of SARS-CoV-2 (PASC), referred to as "Long-COVID," characterized by persistent physical and mental fatigue. However, the exact pathogenetic mechanisms affecting the brain are still not well-understood. There is increasing evidence of neurovascular inflammation in the brain. However, the precise role of the neuroinflammatory response that contributes to the disease severity of COVID-19 and long COVID pathogenesis is not clearly understood. Here, we review the reports that the SARS-CoV-2 spike protein can cause blood-brain barrier (BBB) dysfunction and damage neurons either directly, or via activation of brain mast cells and microglia and the release of various neuroinflammatory molecules. Moreover, we provide recent evidence that the novel flavanol eriodictyol is particularly suited for development as an effective treatment alone or together with oleuropein and sulforaphane (ViralProtek®), all of which have potent anti-viral and anti-inflammatory actions.

The Impact of Information About COVID-19 on the Endocrine Stress System and Cognitive Distortions

The coronavirus disease 2019 (COVID-19) pandemic is one of the major health concerns worldwide affecting not only human physical health but also contributing to the development of many mental disorders including impairment of the cognitive function. It is highly conceivable that elevation of the stress hormones, i.e., glucocorticoids and catecholamines, due to the infection, as well as the presence of psychosocial stressors, such as COVID-19 information, play a critical role in the development of these disorders. In the present study, the potential impact of exposure to COVID-19 information on the cognitive distortion and stress levels was analyzed in a population of 32 first-year medical sciences students using the stress assessment questionnaire (SAQ) and the posttraumatic cognitions inventory (PTCI) surveys. Both surveys demonstrated no acute change in the stress and post-traumatic cognition levels between medical sciences students who were either exposed or not to information about COVID-19. Interestingly, analysis of the stress and cognition points across the first and second measurements of the SAQ categories revealed a significant change in the control group but not in the experimental group. In addition, there was no significant difference among groups when considering the time*group factor. To conclude, we found that exposure to information about COVID-19 did not contribute acutely to cognitive distortion and stress levels among participating students. The previous exposure to COVID-19-related information from media and living during the COVID-19 pandemic era might have enhanced the awareness of the students to the situation.

Psychological Morbidity After COVID-19 Critical Illness

Survivors of ICU hospitalizations often experience severe and debilitating symptoms long after critical illness has resolved. Many patients experience notable psychiatric sequelae such as depression, anxiety, and posttraumatic stress disorder (PTSD) that may persist for months to years after discharge. The COVID-19 pandemic has produced large numbers of critical illness survivors, warranting deeper understanding of psychological morbidity after COVID-19 critical illness. Many patients with critical illness caused by COVID-19 experience substantial post-ICU psychological sequelae mediated by specific pathophysiologic, iatrogenic, and situational risk factors. Existing and novel interventions focused on minimizing psychiatric morbidity need to be further investigated to improve critical care survivorship after COVID-19 illness. This review proposes a framework to conceptualize three domains of risk factors (pathophysiologic, iatrogenic, and situational) associated with psychological morbidity caused by COVID-19 critical illness: (1) direct and indirect effects of the COVID-19 virus in the brain; (2) iatrogenic complications of ICU care that may disproportionately affect patients with COVID-19; and (3) social isolation that may worsen psychological morbidity. In addition, we review current interventions to minimize psychological complications after critical illness.

Short Communication: Stellate Ganglion Blockade for Persistent Olfactory and Gustatory Symptoms Post-COVID-19

One hundred ninety-five patients presenting with post-COVID symptomology, including parosmia and dysgeusia, underwent reversible stellate ganglion blockade. Stellate ganglion blockade was performed at an outpatient facility, and patients were evaluated via survey at seven days post-injection. Of the 195 participants, ages ranged from 18-69 years of age with the breakdown of sexes being females n = 157 and males n = 38. The most significant finding was a reported improvement in olfaction post-injection in 87.4% of subjects. The effectiveness of this novel treatment for post-COVID is promising and warrants further investigation.

Diabetes and COVID-19: Short- and Long-Term Consequences

When the corona pandemic commenced more than two years ago, it was quickly recognized that people with metabolic diseases show an augmented risk of severe COVID-19 and an increased mortality compared to people without these comorbidities. Furthermore, an infection with SARS-CoV-2 has been shown to lead to an aggravation of metabolic diseases and in single cases to new-onset metabolic disorders. In addition to the increased risk for people with diabetes in the acute phase of COVID-19, this patient group also seems to be more often affected by long-COVID and to experience more long-term consequences than people without diabetes. The mechanisms behind these discrepancies between people with and without diabetes in relation to COVID-19 are not completely understood yet and will require further research and follow-up studies during the following years. In the current review, we discuss why patients with diabetes have this higher risk of developing severe COVID-19 symptoms not only in the acute phase of the disease but also in relation to long-COVID, vaccine breakthrough infections and re-infections. Furthermore, we discuss the effects of lockdown on glycemic control.

Neurological Involvement in COVID-19 Among Non-Hospitalized Adolescents and Young Adults

Introduction

Coronavirus disease 2019 (COVID-19) is prevalent among young people, and neurological involvement has been reported. We investigated neurological symptoms, cognitive test results, and biomarkers of brain injury, as well as associations between these variables in non-hospitalized adolescents and young adults with COVID-19.

Methods

This study reports baseline findings from an ongoing observational cohort study of COVID-19 cases and non-COVID controls aged 12–25 years (Clinical Trials ID: NCT04686734). Symptoms were charted using a standardized questionnaire. Cognitive performance was evaluated by applying tests of working memory, verbal learning, delayed recall, and recognition. The brain injury biomarkers, neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAp), were assayed in serum samples using ultrasensitive immunoassays.

Results

A total of 405 COVID-19 cases and 111 non-COVID cases were prospectively included. Serum Nfl and GFAp concentrations were significantly elevated in COVID-19 cases as compared with non-COVID controls (p = 0.050 and p = 0.014, respectively). The COVID-19 cases reported more fatigue (p < 0.001) and post-exertional malaise (PEM) (p = 0.001) compared to non-COVID-19 controls. Cognitive test performance and clinical neurological examination did not differ across the two groups. Within the COVID-19 group, there were no associations between symptoms, cognitive test results, and NfL or GFAp levels. However, fatigue and PEM were strongly associated with older age and female sex.

Conclusions

Non-hospitalized adolescents and young adults with COVID-19 reported more fatigue and PEM and had slightly elevated levels of brain injury markers, but showed normal cognitive performance. No associations were found between symptoms, brain injury markers, and cognitive test results, but fatigue and PEM were strongly related to female sex and older age.

How Different Pre-existing Mental Disorders and Their Co-occurrence Affects COVID-19 Clinical Outcomes? A Real-World Data Study in the Southern United States

Background

Although a psychiatric history might be an independent risk factor for COVID-19 infection and mortality, no studies have systematically investigated how different clusters of pre-existing mental disorders may affect COVID-19 clinical outcomes or showed how the coexistence of mental disorder clusters is related to COVID-19 clinical outcomes.

Methods

Using a retrospective cohort study design, a total of 476,775 adult patients with lab-confirmed and probable COVID-19 between March 06, 2020 and April 14, 2021 in South Carolina, United States were included in the current study. The electronic health record data of COVID-19 patients were linked to all payer-based claims data through the SC Revenue and Fiscal Affairs Office. Pre-existing mental disorder diagnoses from Jan 2, 2019 to Jan 14, 2021 were extracted from the patients' healthcare utilization data via ICD-10 codes.

Results

There is an elevated risk of COVID-19-related hospitalization and death among participants with pre-existing mental disorders adjusting for key socio-demographic and comorbidity covariates. Co-occurrence of any two clusters was positively associated with COVID-19-related hospitalization and death. The odds ratio of being hospitalized was 1.26 (95% CI: 1.151, 1.383) for patients with internalizing and externalizing disorders, 1.65 (95% CI: 1.298, 2.092) for internalizing and thought disorders, 1.76 (95% CI: 1.217, 2.542) for externalizing and thought disorders, and 1.64 (95% CI: 1.274, 2.118) for three clusters of mental disorders.

Conclusions

Pre-existing internalizing disorders and thought disorders are positively related to COVID-19 hospitalization and death. Co-occurrence of any two clusters of mental disorders have elevated risk of COVID-19-related hospitalization and death compared to those with a single cluster.

Coronavirus disease 2019 (COVID-19) update: From metabolic reprogramming to immunometabolism

The field of immunometabolism investigates and describes the effects of metabolic rewiring in immune cells throughout activation and the fates of these cells. Recently, it has been appreciated that immunometabolism plays an essential role in the progression of viral infections, cancer, and autoimmune diseases. Regarding COVID‐19, the aberrant immune response underlying the progression of diseases establishes two major respiratory pathologies, including acute respiratory distress syndrome (ARDS) or pneumonia‐induced acute lung injury (ALI). Both innate and adaptive immunity (T cell‐based) were impaired in the course of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. Current findings have deciphered that macrophages (innate immune cells) are involved in the inflammatory response seen in COVID‐19. It has been demonstrated that immune system cells can change metabolic reprogramming in some conditions, including autoimmune diseases, cancer, and infectious disease, including COVID‐19. The growing findings on metabolic reprogramming in COVID‐19 allow an exploration of metabolites with immunomodulatory properties as future therapies to combat this hyperinflammatory response. The elucidation of the exact role and mechanism underlying this metabolic reprograming in immune cells could help apply more precise approaches to initial diagnosis, prognosis, and in‐hospital therapy. This report discusses the latest findings from COVID‐19 on host metabolic reprogramming and immunometabolic responses.

Impact of SARS-CoV-2 on Host Factors Involved in Mental Disorders

COVID-19, caused by SARS-CoV-2, is a systemic illness due to its multiorgan effects in patients. The disease has a detrimental impact on respiratory and cardiovascular systems. One early symptom of infection is anosmia or lack of smell; this implicates the involvement of the olfactory bulb in COVID-19 disease and provides a route into the central nervous system. However, little is known about how SARS-CoV-2 affects neurological or psychological symptoms. SARS-CoV-2 exploits host receptors that converge on pathways that impact psychological symptoms. This systemic review discusses the ways involved by coronavirus infection and their impact on mental health disorders. We begin by briefly introducing the history of coronaviruses, followed by an overview of the essential proteins to viral entry. Then, we discuss the downstream effects of viral entry on host proteins. Finally, we review the literature on host factors that are known to play critical roles in neuropsychiatric symptoms and mental diseases and discuss how COVID-19 could impact mental health globally. Our review details the host factors and pathways involved in the cellular mechanisms, such as systemic inflammation, that play a significant role in the development of neuropsychological symptoms stemming from COVID-19 infection.

The interface of COVID-19, diabetes, and depression

Comorbid diabetes with depression is a challenging and often under-recognized clinical problem. During the current COVID-19 pandemic, a communicable disease is thriving on the increasing incidences of these non-communicable diseases. These three different health problems are bidirectionally connected forming a vicious cycle. Firstly, depressed individuals show a higher risk of developing diabetes and patients with diabetes have a higher risk of developing symptoms of depression. Secondly, patients with diabetes have a higher risk of developing severe COVID-19 as well as of experiencing breakthrough infections. Thirdly, in both patients with type 2 diabetes and in COVID-19 survivors the prevalence of depression seems to be increased. Fourthly, lockdown and quarantine measurements during the COVID-19 pandemic has led to an increase in depression. Therefore, it is of importance to increase the awareness of this interface between depression, diabetes and COVID-19. Finally, as symptoms of post-COVID, diabetes and depression may be overlapping, there is a need for educating skilled personnel in the management of these comorbidities.

SARS-CoV-2 Psychiatric Sequelae: A Review of Neuroendocrine Mechanisms and Therapeutic Strategies

From the earliest days of the coronavirus disease 2019 (COVID-19) pandemic, there have been reports of significant neurological and psychological symptoms following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. This narrative review is designed to examine the potential psychoneuroendocrine pathogenic mechanisms by which SARS-CoV-2 elicits psychiatric sequelae as well as to posit potential pharmacologic strategies to address and reverse these pathologies. Following a brief overview of neurological and psychological sequelae from previous viral pandemics, we address mechanisms by which SARS-CoV-2 could enter or otherwise elicit changes in the CNS. We then examine the hypothesis that COVID-19-induced psychiatric disorders result from challenges to the neuroendocrine system, in particular the hypothalamic-pituitary-adrenal stress axis and monoamine synthesis, physiological mechanisms that are only further enhanced by the pandemic-induced social environment of fear, isolation, and socioeconomic pressure. Finally, we evaluate several FDA-approved therapeutics in the context of COVID-19-induced psychoneuroendocrine disorders.

[Practical recommendations for screening and management of functional disorders of the adrenal cortex in cases of SARS-CoV-2 infections]

Diseases of the adrenal cortex require particular attention during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Firstly, SARS-CoV‑2 infections can give rise to extrapulmonary manifestations and cause endocrine disorders, particularly in the adrenal cortex. Furthermore, patients with pre-existing insufficiency of the adrenal cortex or hypercortisonism are particularly at risk from a severe infection such as SARS-CoV‑2, to suffer from additional complications or a more severe course of a SARS-CoV‑2 infection with a higher mortality. Especially in hemodynamically unstable patients with a SARS-CoV‑2 infection, diseases of the adrenal glands should also be considered in the differential diagnostics and if necessary clarified, if this is not already known. Prolonged treatment of patients with a SARS-CoV‑2 infection with regimens containing high doses of glucocorticoids can also result in a secondary adrenal insufficiency. In order to address these special aspects, some practical recommendations for the diagnostic and therapeutic management of functional disorders of the adrenal glands in patients with a SARS-CoV‑2 infection are therefore presented.

Risk Factors for Relapse in People with Severe Mental Disorders during the COVID-19 Pandemic: A Multicenter Retrospective Study

Background: Evidence suggests that different variables associated with the COVID-19 pandemic may increase the risk of relapse in people with Severe Mental Disorders (SMDs). However, no studies have yet looked closely at the different risk factors involved to determine their influence on the worsening of these patients’ illnesses. Objective: To analyze which variables related to the COVID-19 pandemic have increased the risk of relapse in patients with SMDs. Method: A multicenter retrospective cohort study in which data were collected from 270 patients with mental disorders who had been under follow-up in day hospitals during the year 2020. Results: The proportion of full mental health inpatient admissions was significantly higher in those who lost their employment (40.7% vs. 18.1%; p = 0.01), in those who were not receiving psychotherapy interventions (33.9% vs. 16.6%; p = 0.006), and in those who were not receiving occupational therapy (25.7% vs. 13.6%: p = 0.013). Significant associations were detected between urgent mental health consultations, the number of COVID-19 symptoms (B = 0.274; p = 0.02), and the low-income group (1.2424 vs. 0.4583; p = 0.018). Conclusions: COVID-19 symptoms and certain consequences of the pandemic, such as loss of employment, economic hardship, and loss of interventions, have brought about clinical worsening in people with SMDs. Knowledge of these factors is important for health-related decision-making in future outbreaks or pandemics.

The Immunomodulatory Function of Vitamin D, with Particular Reference to SARS-CoV-2

Vaccines are the only way to reduce the morbidity associated to SARS-CoV-2 infection. The appearance of new mutations urges us to increase the effectiveness of vaccines as a complementary alternative. In this context, the use of adjuvant strategies has improved the effectiveness of different vaccines against virus infections such as dengue, influenza, and common cold. Recent reports on patients infected by COVID-19 reveal that low levels of circulating vitamin D correlate with a severe respiratory insufficiency. The immunomodulatory activity of this micronutrient attenuates the synthesis of pro-inflammatory cytokines and at the same time, increases antibody production. Therefore, the present review proposes the use of vitamin D as adjuvant micronutrient to increase the efficacy of vaccines against SARS-CoV-2 infection.

Understanding the Impact of the COVID-19 Pandemic, Lockdowns and Social Isolation on Sleep Quality

The uncertain, ever-changing and an ongoing nature of the COVID-19 pandemic means that it may take some time before we can fully appreciate the negative effect of the pandemic and lockdown on our sleep and mental health. It is increasingly recognised that in the aftermath of pandemic, several persistent sleep, neuropsychiatric and physical sequelae may continue long after the pandemic is over. A body of evidence to date also highlights a significant disparity in sleep and mental health difficulties in specific vulnerable groups in the community, with different temporal profiles and sleep issues that are reported. In this perspective, we argue for a possible mechanistic impact of the COVID-19 pandemic, with its imposed restrictions and social isolation on sleep quality. We similarly discuss some of the potential international differences, as well as similarities, behind reported idiosyncratic biological vulnerabilities that may have contributed to the genesis of sleep issues. Lastly, we propose some possible implementations and innovations that may be needed in restructuring of sleep disorders services in order to benefit recovering COVID-19 patients.

COVID-19 and metabolic disease: mechanisms and clinical management

Up to 50% of the people who have died from COVID-19 had metabolic and vascular disorders. Notably, there are many direct links between COVID-19 and the metabolic and endocrine systems. Thus, not only are patients with metabolic dysfunction (eg, obesity, hypertension, non-alcoholic fatty liver disease, and diabetes) at an increased risk of developing severe COVID-19 but also infection with SARS-CoV-2 might lead to new-onset diabetes or aggravation of pre-existing metabolic disorders. In this Review, we provide an update on the mechanisms of how metabolic and endocrine disorders might predispose patients to develop severe COVID-19. Additionally, we update the practical recommendations and management of patients with COVID-19 and post-pandemic. Furthermore, we summarise new treatment options for patients with both COVID-19 and diabetes, and highlight current challenges in clinical management.

Pituitary-Adrenal Responses and Glucocorticoid Receptor Expression in Critically Ill Patients with COVID-19

The hypothalamus-pituitary-adrenal (HPA) axis was described as the principal component of the stress response 85 years ago, along with the acute-phase reaction, and the defense response at the tissue level. The orchestration of these processes is essential since systemic inflammation is a double-edged sword; whereas inflammation that is timely and of appropriate magnitude is beneficial, exuberant systemic inflammation incites tissue damage with potentially devastating consequences. Apart from its beneficial cardiovascular and metabolic effects, cortisol exerts a significant immunoregulatory role, a major attribute being that it restrains the excessive inflammatory reaction, thereby preventing unwanted tissue damage. In this review, we will discuss the role of the HPA axis in the normal stress response and in critical illness, especially in critically ill patients with coronavirus disease 2019 (COVID-19). Finally, a chapter will be dedicated to the findings from clinical studies in critical illness and COVID-19 on the expression of the mediator of glucocorticoid actions, the glucocorticoid receptor (GCR).

The immune-neuroendocrine system in COVID-19, advanced age and rheumatic diseases

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The immune-neuroendocrine system is essential to maintain homeostasis specially during stress situations. COVID-19 infection, produce stress, and activates the immune–neuroendocrine system. During the COVID-19 pandemic, multiple studies indicate that the most vulnerable populations are older adults and patients with comorbidities including autoimmune rheumatic diseases. These patients suffer from extremely important situation that favors the inflammatory hyper response due to an inadequate reaction of the immune-neuroendocrine system. This review aims to analyze the findings of the effect of COVID-19 on the hypothalamic–pituitary–adrenal, hypothalamic–pituitary–gonadal, hypothalamic–pituitary–thyroid, hypothalamic–pituitary–prolactin axes, and central nervous system, as well as the response to this viral infection in older adults and patients with rheumatic diseases and perspectives about this subject.

The Stress Axis in Obesity and Diabetes Mellitus: An Update

The hypothalamic–pituitary–adrenal axis is a tightly regulated system that represents one of the body’s mechanisms for responding to acute and chronic stress. Prolonged stress and/or inadequate regulation of the stress system can lead to a condition of chronic hypercortisolism or, in some cases, a blunted cortisol response to stress, contributing to insulin resistance, increased adiposity and type 2 diabetes mellitus. Moreover, acute and chronic stress can exacerbate or worsen metabolic conditions by supporting an inflammatory state and a tight relationship between stress, inflammation and adipose tissue has been reported and has been a growing subject of interest in recent years. We reviewed and summarized the evidence supporting hypothalamic–pituitary–adrenal axis dysregulation as an important biological link between stress, obesity, inflammation and type 2 diabetes mellitus. Furthermore, we emphasized the possible role of infectious-related stress such as SarsCov2 infection in adrenal axis dysregulation, insulin resistance and diabetes in a bidirectional link. Understanding and better defining the links between stress and obesity or diabetes could contribute to further definition of the pathogenesis and the management of stress-related complications, in which the HPA axis dysregulation has a primary role.

The impact of the COVID-19 pandemic and its related restrictions on people with pre-existent mental health conditions: A scoping review

CONTEXT

Globally, governments have introduced a variety of public health measures including restrictions and reducing face-to-face contact, to control the spread of COVID-19. This has implications for mental health services in terms of support and treatment for vulnerable groups such as people with pre-existent mental health conditions. However, there is limited evidence of the impact of COVID-19 and its related restrictions on people with pre-existent mental health conditions.

OBJECTIVES

To identify the impact of COVID-19 and its related restrictions on people with pre-existent mental health conditions.

METHODS

A scoping review of the literature was employed. Eight electronic databases (PsycINFO, Cochrane, Web of Science, MEDLINE, EMBASE, CINAHL, Scopus, Academic Search Complete) were searched and 2566 papers identified. 30 papers met the criteria for this review and findings were summarised under three key review questions.

RESULTS

COVID-19 and its related restrictions have had a notable effect on people with pre-existent mental health conditions. Public health restrictions have contributed to increased levels of social isolation, loneliness, and reduced opportunities for people to connect with others. Reduced access to health services and treatments has compounded matters for those seeking support. Exacerbation and deterioration of symptoms are commonly reported and can lead to greater susceptibility to COVID-19 infection.

IMPLICATIONS

The importance of proactive planning, alternative accessible healthcare services and supports for vulnerable and at-risk groups is illuminated. Increased monitoring, early intervention and individually tailored care strategies are advocated. Recommendations revolve around the need for enhanced provision of remote support strategies facilitated using technology enhanced resources. ACCESSIBLE SUMMARY.

Does inflammation link stress to poor COVID-19 outcome?

Coronavirus disease 2019 (COVID-19) continues to ravage communities across the world. Despite its primary effect on the respiratory system, the virus does not solely impact those with underlying lung conditions as initially predicted. Indeed, prognosis is worsened (often fatal) in patients with pre-existing hyperinflammatory responses (e.g., hypertension, obesity and diabetes), yet the mechanisms by which this occurs are unknown. A number of psychological conditions are associated with inflammation, suggesting that these may also be significant risk factors for negative outcomes of COVID-19. In this review, we evaluate preclinical and clinical literature suggesting that chronic stress-induced hyperinflammation interacts synergistically with COVID-19-related inflammation, contributing to a potentially fatal cytokine storm syndrome. In particular, we hypothesize that both chronic stress and COVID-19-related hyperinflammation are a product of glucocorticoid insufficiency. We discuss the devastating effects of SARS-CoV-2 on structural and functional aspects of the biological stress response and how these induce exaggerated inflammatory responses, particularly interleukin (IL)-6 hypersecretion. We postulate that chronic stress should be considered a significant risk factor for adverse COVID-19-related health outcomes, given overlapping peripheral and central immune dysregulation in both conditions. We conclude by discussing how people with a history of chronic stress could mitigate their risk for COVID-19 complications, identifying specific strategies that can be implemented during self-isolation.

Brain Stress Mapping in COVID-19 Survivors Using MR Spectroscopy: New Avenue of Mental Health Status Monitoring$

Coronavirus (COVID-19) has emerged as a human catastrophe worldwide, and it has impacted human life more detrimentally than the combined effect of World Wars I and II. Various research studies reported that the disease is not confined to the respiratory system but also leads to neurological and neuropsychiatric disorders suggesting that the virus is potent to affect the central nervous system (CNS). Moreover, the damage to CNS may continue to rise even after the COVID-19 infection subsides which may further induce a long-term impact on the brain, resulting in cognitive impairment. Neuroimaging techniques is the ideal platform to detect and quantify pathological manifestations in the brain of COVID-19 survivors. In this context, a scheme based on structural, spectroscopic, and behavioral studies could be executed to monitor the gradual changes in the brain non-invasively due to COVID-19 which may further help in quantifying the impact of COVID-19 on the mental health of the survivors. Extensive research is required in this direction for identifying the mechanism and implications of COVID-19 in the brain. Cohort studies are urgently required for monitoring the effects of this pandemic on individuals of various subtypes longitudinally.

COVID-19 associated nervous system manifestations

The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic in the last year. Along with major respiratory distress, a myriad of neurological manifestations was also reported to be associated with COVID-19 patients. These cases indicate that SARS-CoV-2 can be considered as an opportunistic pathogen of the brain. SARS-CoV-2 enters the brain through the olfactory bulb, retrograde axonal transport from peripheral nerve endings, or via hematogenous or lymphatic routes. Notably, COVID-19 infection can cause or even present with different neurological features including encephalopathy, impaired consciousness, confusion, agitation, seizure, ataxia, headache, anosmia, ageusia, neuropathies, and neurodegenerative diseases. In this paper, we provide a brief review of observed neurological manifestations associated with COVID-19.

Viral infiltration of pancreatic islets in patients with COVID-19

Metabolic diseases are associated with an increased risk of severe COVID-19 and conversely, new-onset hyperglycemia and complications of preexisting diabetes have been observed in COVID-19 patients. Here, we performed a comprehensive analysis of pancreatic autopsy tissue from COVID-19 patients using immunofluorescence, immunohistochemistry, RNA scope and electron microscopy and detected SARS-CoV-2 viral infiltration of beta-cells in all patients. Using SARS-CoV-2 pseudoviruses, we confirmed that isolated human islet cells are permissive to infection. In eleven COVID-19 patients, we examined the expression of ACE2, TMPRSS and other receptors and factors, such as DPP4, HMBG1 and NRP1, that might facilitate virus entry. Whereas 70% of the COVID-19 patients expressed ACE2 in the vasculature, only 30% displayed ACE2-expression in beta-cells. Even in the absence of manifest new-onset diabetes, necroptotic cell death, immune cell infiltration and SARS-CoV-2 viral infection of pancreatic beta-cells may contribute to varying degrees of metabolic dysregulation in patients with COVID-19.

New-onset hyperglycemia and complications of preexisting diabetes have been observed in COVID-19 patients, however, the underlying mechanisms are not fully understood. Here, the authors show that SARS-CoV-2 is detectable in both endocrine and exocrine cells of the pancreata of patients with COVID-19.

The impact of COVID-19 on diagnostic biomarkers in neuropsychiatric and neuroimmunological diseases: a review

Coronavirus disease 2019 (COVID-19) is an infectious respiratory disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence-based emerging reports of neurological manifestations show that SARS-CoV-2 can attack the nervous system. However, little is known about the biomarkers in disease in neuropsychiatric and neuroimmunological disorders. One of the important keys in the management of COVID-19 is an accurate diagnosis. Biomarkers could provide valuable information in the early detection of disease etiology, diagnosis, further treatment, and prognosis. Moreover, ongoing investigations on hematologic, biochemical, and immunologic biomarkers in nonsevere, severe, or fatal forms of COVID-19 patients provide an urgent need for the identification of clinical and laboratory predictors. In addition, several cytokines acting through mechanisms to emerge immune response against SARS-CoV-2 infection are known to play a major role in neuroinflammation. Considering the neuroinvasive potential of SARS-CoV-2, which can be capable of triggering a cytokine storm, the current evidence on inflammation in psychiatry and neurodegenerative by emerging neuroinflammation is discussed in this review. We also highlighted the hematologic, biochemical, and immunologic biomarkers in COVID-19 diagnosis. COVID-19 prognostic biomarkers in patients with neuropsychiatric and neuroimmunological diseases are also explained.

COVID-19 and central nervous system interplay: A big picture beyond clinical manifestation

The coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been declared a pandemic. Global research updates confirm that the infected patients manifest a range of clinical symptoms and sometimes remain entirely asymptomatic, posing a greater threat to the people coming in contact. Despite several case reports coming up every day, our knowledge about the neurotropic mechanism of the SARS-CoV-2, immunological responses, and the mode of disease progression and mechanism of cross-talk between the central nervous system (CNS), heart, lungs, and other major organs is not complete. Report of anosmia, ataxia, dysgeusia, and altered psychological status of the infected COVID-19 patients offers some clue to the possible route of viral entry and multiplication. In this review, we have critically assessed the involvement of CNS dysregulation in COVID-19 patients. The probable mechanism of immunological responses, the impairment of the coagulation pathway, the onset of cytokine storm, its interplay with the HPA axis, and hypoxia are discussed in detail here. Based on the latest research findings and some case reports of hospitalized COVID-19 patients, it is evident that the CNS involvement in disease progression is alarming. Accurate and timely detection of viral load in CNS is necessary to allow prompt and effective treatment modalities.

Possible entry sites of SARS-CoV-2 to the central nervous system of human being and the downstream manifestations.

"What If We Get Sick?": Spanish Adaptation and Validation of the Fear of Illness and Virus Evaluation Scale in a Non-clinical Sample Exposed to the COVID-19 Pandemic

Distinct sources of stress have emerged during the COVID-19 pandemic. Particularly, fear is expected to generate significant psychological burden on individuals and influence on either unsafe behavior that may hinder recovery efforts or virus-mitigating behaviors. However, little is known about the properties of measures to capture them in research and clinical settings. To resolve this gap, we evaluated the psychometric properties of a novel measure of fear of illness and viruses and tested its predictive value for future development of distress. We extracted a random sample of 450 Chilean adult participants from a large cross-sectional survey panel and invited to participate in this intensive longitudinal study for 35 days. Of these, 163 ended up enrolling in the study after the demanding nature of the measurement schedule was clearly explained to them. For this final sample, we calculated different Confirmatory Factor Analyses (CFA) to evaluate the preliminary proposed structure for the instrument. Complementarily, we conducted a content analysis of the items to qualitatively extract its latent structure, which was also subject to empirical test via CFA. Results indicated that the original structure did not fit the data well; however, the new proposed structure based on the content analysis did. Overall, the modified instrument showed good reliability through all subscales both by its internal consistency with Cronbach's alphas ranging from 0.814 to 0.913, and with test-retest correlations ranging from 0.715 to 0.804. Regarding its convergent validity, individuals who scored higher in fears tended to also score higher in depressive and posttraumatic stress symptoms at baseline. Furthermore, higher fears at baseline predicted a higher score in posttraumatic stress symptomatology 7 days later. These results provide evidence for the validity, reliability, and predictive performance of the scale. As the scale is free and multidimensional potentially not circumscribed to COVID-19, it might work as a step toward understanding the psychological impact of current and future pandemics, or further life-threatening health situations of similar characteristics. Limitations, practical implications, and future directions for research are discussed.

Long-COVID syndrome-associated brain fog and chemofog: Luteolin to the rescue

COVID-19 leads to severe respiratory problems, but also to long-COVID syndrome associated primarily with cognitive dysfunction and fatigue. Long-COVID syndrome symptoms, especially brain fog, are similar to those experienced by patients undertaking or following chemotherapy for cancer (chemofog or chemobrain), as well in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) or mast cell activation syndrome (MCAS). The pathogenesis of brain fog in these illnesses is presently unknown but may involve neuroinflammation via mast cells stimulated by pathogenic and stress stimuli to release mediators that activate microglia and lead to inflammation in the hypothalamus. These processes could be mitigated by phytosomal formulation (in olive pomace oil) of the natural flavonoid luteolin.

The transCampus Metabolic Training Programme Explores the Link of SARS-CoV-2 Virus to Metabolic Disease

Currently, we are experiencing a true pandemic of a communicable disease by the virus SARS-CoV-2 holding the whole world firmly in its grasp. Amazingly and unfortunately, this virus uses a metabolic and endocrine pathway via ACE2 to enter our cells causing damage and disease. Our international research training programme funded by the German Research Foundation has a clear mission to train the best students wherever they may come from to learn to tackle the enormous challenges of diabetes and its complications for our society. A modern training programme in diabetes and metabolism does not only involve a thorough understanding of classical physiology, biology and clinical diabetology but has to bring together an interdisciplinary team. With the arrival of the coronavirus pandemic, this prestigious and unique metabolic training programme is facing new challenges but also new opportunities. The consortium of the training programme has recognized early on the need for a guidance and for practical recommendations to cope with the COVID-19 pandemic for the community of patients with metabolic disease, obesity and diabetes. This involves the optimal management from surgical obesity programmes to medications and insulin replacement. We also established a global registry analyzing the dimension and role of metabolic disease including new onset diabetes potentially triggered by the virus. We have involved experts of infectious disease and virology to our faculty with this metabolic training programme to offer the full breadth and scope of expertise needed to meet these scientific challenges. We have all learned that this pandemic does not respect or heed any national borders and that we have to work together as a global community. We believe that this transCampus metabolic training programme provides a prime example how an international team of established experts in the field of metabolism can work together with students from all over the world to address a new pandemic.

Neurological Consequences of SARS-CoV-2 Infection and Concurrence of Treatment-Induced Neuropsychiatric Adverse Events in COVID-19 Patients: Navigating the Uncharted

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to the angiotensin-converting enzyme 2 (ACE2) receptor and invade the human cells to cause COVID-19-related pneumonia. Despite an emphasis on respiratory complications, the evidence of neurological manifestations of SARS-CoV-2 infection is rapidly growing, which is substantially contributing to morbidity and mortality. The neurological disorders associated with COVID-19 may have several pathophysiological underpinnings, which are yet to be explored. Hypothetically, SARS-CoV-2 may affect the central nervous system (CNS) either by direct mechanisms like neuronal retrograde dissemination and hematogenous dissemination, or via indirect pathways. CNS complications associated with COVID-19 include encephalitis, acute necrotizing encephalopathy, diffuse leukoencephalopathy, stroke (both ischemic and hemorrhagic), venous sinus thrombosis, meningitis, and neuroleptic malignant syndrome. These may result from different mechanisms, including direct virus infection of the CNS, virus-induced hyper-inflammatory states, and post-infection immune responses. On the other hand, the Guillain-Barre syndrome, hyposmia, hypogeusia, and myopathy are the outcomes of peripheral nervous system injury. Although the therapeutic potential of certain repurposed drugs has led to their off-label use against COVID-19, such as anti-retroviral drugs (remdesivir, favipiravir, and lopinavir-ritonavir combination), biologics (tocilizumab), antibiotics (azithromycin), antiparasitics (chloroquine and hydroxychloroquine), and corticosteroids (dexamethasone), unfortunately, the associated clinical neuropsychiatric adverse events remains a critical issue. Therefore, COVID-19 represents a major threat to the field of neuropsychiatry, as both the virus and the potential therapies may induce neurologic as well as psychiatric disorders. Notably, potential COVID-19 medications may also interact with the medications of pre-existing neuropsychiatric diseases, thereby further complicating the condition. From this perspective, this review will discuss the possible neurological manifestations and sequelae of SARS-CoV-2 infection with emphasis on the probable underlying neurotropic mechanisms. Additionally, we will highlight the concurrence of COVID-19 treatment-associated neuropsychiatric events and possible clinically relevant drug interactions, to provide a useful framework and help researchers, especially the neurologists in understanding the neurologic facets of the ongoing pandemic to control the morbidity and mortality.

Overview of COVID-19 and neurological complications

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

Pathophysiological Clues to How the Emergent SARS-CoV-2 Can Potentially Increase the Susceptibility to Neurodegeneration

Along with emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019, a myriad of neurologic symptoms, associated with structural brain changes, were reported. In this paper, we provide evidence to critically discuss the claim that the survived patients could possibly be at increased risk for neurodegenerative diseases via various mechanisms. This virus can directly invade the brain through olfactory bulb, retrograde axonal transport from peripheral nerve endings, or via hematogenous or lymphatic routes. Infection of the neurons along with peripheral leukocytes activation results in pro-inflammatory cytokine increment, rendering the brain to neurodegenerative changes. Also, occupation of the angiotensin-converting enzyme 2 (ACE-2) with the virus may lead to a decline in ACE-2 activity, which acts as a neuroprotective factor. Furthermore, acute respiratory distress syndrome (ARDS) and septicemia induce hypoxemia and hypoperfusion, which are locally exacerbated due to the hypercoagulable state and micro-thrombosis in brain vessels, leading to oxidative stress and neurodegeneration. Common risk factors for COVID-19 and neurodegenerative diseases, such as metabolic risk factors, genetic predispositions, and even gut microbiota dysbiosis, can contribute to higher occurrence of neurodegenerative diseases in COVID-19 survivors. However, it should be considered that severity of the infection, the extent of neurologic symptoms, and the persistence of viral infection consequences are major determinants of this association. Importantly, whether this pandemic will increase the overall incidence of neurodegeneration is not clear, as a high percentage of patients with severe form of COVID-19 might probably not survive enough to develop neurodegenerative diseases.

Impact of COVID-19 in the Mental Health in Elderly: Psychological and Biological Updates

Since December 2019, the world has been experiencing the challenge of facing coronavirus disease-19 (COVID-19), a severe infectious disease caused by the new coronavirus, SARS-CoV-2. The individuals with the most severe symptoms and the highest risk of death are the elderly and those with chronic illness. Among chronic conditions, those with a certain degree of chronic inflammation may predispose to a more severe evolution of COVID-19. Elderly with psychiatric disorders can present a persistent inflammatory state, a characteristic of the age’s immunological senescence, but the disorder can accentuate that. Social isolation is still the safest way to avoid contamination. However, isolated older people may have or worsen mental health conditions due to isolation and health concerns. In this scenario, a SARS-CoV-2 infection may progress to more severe disease. Conversely, COVID-19 can predispose or aggravate psychiatric disorders, as it induces a cytokine storm, causing systemic hyper inflammation. It may damage the blood-brain barrier, resulting in inflammation in the central nervous system. Besides, SARS-CoV-2 is likely to reach and trigger an inflammatory process directly in the nervous system. This review makes an update about research on the mental health of the elderly during the pandemic. Also, it discusses the vulnerability of these individuals in the face of stress and in the case of contracting COVID-19, considering mainly the stress’s hormonal and inflammatory mechanisms. Finally, the review points out possible care and attention strategies and entertainment and activities that can reduce the damage to mental and physical health and improve the elderly’s quality of life.

Graphical abstract

A Brain Capital Grand Strategy: toward economic reimagination

‘I have not found among my possessions anything which I hold more dear than, or value so much as, my knowledge of the actions of great people, acquired by long experience in contemporary affairs, and a continual study of antiquity.’ The Prince, Machiavelli

Patterns of mental health problems before and after easing COVID-19 restrictions: Evidence from a 105248-subject survey in general population in China

BACKGROUND

The COVID-19 pandemic has alarming implications for individual and population level mental health. Although the future of COVID-19 is unknown at present, more countries or regions start to ease restrictions. The findings from this study have provided the empirical evidence of prevalence and patterns of mental disorders in Chinese general population before and after easing most COVID-19 restrictions, and information of the factors associated with these patterns.

METHODS

A cross-sectional population-based online survey was carried out from February to March 2020 in the general population across all provinces in China. The 12-item General Health Questionnaire (GHQ-12) was incorporated in the survey. Latent class analyses were performed to investigate the patterns of mental disorders and multinomial logistic regressions were used to examine how individual and regional risk factors can predict mental disorder patterns.

RESULTS

Four distinctive patterns of mental health were revealed in the general population. After the ease of most COVID-19 restrictions, the prevalence of high risk of mental disorders decreased from 25.8% to 20.9% and prevalence of being high risk of unhappiness and loss of confidence decreased from 10.1% to 8.1%. However, the prevalence of stressed, social dysfunction and unhappy were consistently high before and after easing restrictions. Several regional factors, such as case mortality rate and healthcare resources, were associated with mental health status. Of note, healthcare workers were less likely to have mental disorders, compared to other professionals and students.

CONCLUSIONS

The dynamic management of mental health and psychosocial well-being is as important as that of physical health both before and after the ease of COVID-19 restrictions. Our findings may help in mental health interventions in other countries and regions while easing COVID-19 restrictions.

Endocrine Dysfunction among Patients with COVID-19: A Single-center Experience from a Tertiary Hospital in India

OBJECTIVE

COVID-19 has emerged as a multi-system disease with the potential for endocrine dysfunction. We aimed to study the hormonal profile of hospitalized patients with COVID-19 at a tertiary care referral hospital at Jodhpur, India.

DESIGN

A hospital-based clinical study of endocrine profile of COVID-19 patients conducted from 15th May to 30th June 2020 after ethical approval.

MEASUREMENTS

Fasting blood samples for free thyroxine (T4), free tri-iodothyronine (T3), thyroid stimulating Hormone (TSH), serum prolactin; basal and 1 h post-intramuscular adrenocorticotropic hormone (ACTH) stimulated cortisol, interleukin-6 (IL-6), and high sensitivity C-reactive protein (hsCRP) were collected within 24 h of admission after written informed consent. All hormones and IL-6 were analyzed by chemiluminescent immunoassay. hsCRP was measured by immune-turbidimetric assay.

RESULTS

Of 235 patients studied, 14% had severe disease and 5.5% died. Adrenal insufficiency was present in 14%, most of whom had mild disease. A robust adrenal response was observed in those with severe disease. Basal and post-ACTH serum cortisol were significantly increased in severe disease or those who died compared to those who were mild or asymptomatic. Basal and post-ACTH serum cortisol showed a significant positive correlation with hsCRP but not with IL-6. Low T3 and low T4 syndrome were documented in 25% and 5%, respectively. Serum TSH and FT3 levels declined significantly from asymptomatic to severe category. Hyperprolactinemia was found in 21 patients. hsCRP showed a rising trend with disease severity while IL-6 did not.

CONCLUSIONS

Endocrine dysfunction in the form of adrenal insufficiency, low T3, and low TSH syndrome and hyperprolactinemia were common COVID-19 hospitalized patients.

An Assessment on Impact of COVID-19 Infection in a Gender Specific Manner

Coronavirus disease 2019 (COVID-19) is caused by novel coronavirus Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first time reported in December 2019 in Wuhan, China and thereafter quickly spread across the globe. Till September 19, 2020, COVID-19 has spread to 216 countries and territories. Severe infection of SARS-CoV-2 cause extreme increase in inflammatory chemokines and cytokines that may lead to multi-organ damage and respiratory failure. Currently, no specific treatment and authorized vaccines are available for its treatment. Renin angiotensin system holds a promising role in human physiological system specifically in regulation of blood pressure and electrolyte and fluid balance. SARS-CoV-2 interacts with Renin angiotensin system by utilizing angiotensin-converting enzyme 2 (ACE2) as a receptor for its cellular entry. This interaction hampers the protective action of ACE2 in the cells and causes injuries to organs due to persistent angiotensin II (Ang-II) level. Patients with certain comorbidities like hypertension, diabetes, and cardiovascular disease are under the high risk of COVID-19 infection and mortality. Moreover, evidence obtained from several reports also suggests higher susceptibility of male patients for COVID-19 mortality and other acute viral infections compared to females. Analysis of severe acute respiratory syndrome coronavirus (SARS) and Middle East respiratory syndrome coronavirus (MERS) epidemiological data also indicate a gender-based preference in disease consequences. The current review addresses the possible mechanisms responsible for higher COVID-19 mortality among male patients. The major underlying aspects that was looked into includes smoking, genetic factors, and the impact of reproductive hormones on immune systems and inflammatory responses. Detailed investigations of this gender disparity could provide insight into the development of patient tailored therapeutic approach which would be helpful in improving the poor outcomes of COVID-19. Graphical abstract.

How mental health care should change as a consequence of the COVID-19 pandemic

The unpredictability and uncertainty of the COVID-19 pandemic; the associated lockdowns, physical distancing, and other containment strategies; and the resulting economic breakdown could increase the risk of mental health problems and exacerbate health inequalities. Preliminary findings suggest adverse mental health effects in previously healthy people and especially in people with pre-existing mental health disorders. Despite the heterogeneity of worldwide health systems, efforts have been made to adapt the delivery of mental health care to the demands of COVID-19. Mental health concerns have been addressed via the public mental health response and by adapting mental health services, mostly focusing on infection control, modifying access to diagnosis and treatment, ensuring continuity of care for mental health service users, and paying attention to new cases of mental ill health and populations at high risk of mental health problems. Sustainable adaptations of delivery systems for mental health care should be developed by experts, clinicians, and service users, and should be specifically designed to mitigate disparities in health-care provision. Thorough and continuous assessment of health and service-use outcomes in mental health clinical practice will be crucial for defining which practices should be further developed and which discontinued. For this Position Paper, an international group of clinicians, mental health experts, and users of mental health services has come together to reflect on the challenges for mental health that COVID-19 poses. The interconnectedness of the world made society vulnerable to this infection, but it also provides the infrastructure to address previous system failings by disseminating good practices that can result in sustained, efficient, and equitable delivery of mental health-care delivery. Thus, the COVID-19 pandemic could be an opportunity to improve mental health services.

COVID-19, Mast Cells, Cytokine Storm, Psychological Stress, and Neuroinflammation

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new pandemic infectious disease that originated in China. COVID-19 is a global public health emergency of international concern. COVID-19 causes mild to severe illness with high morbidity and mortality, especially in preexisting risk groups. Therapeutic options are now limited to COVID-19. The hallmark of COVID-19 pathogenesis is the cytokine storm with elevated levels of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-alpha (TNF-α), chemokine (C-C-motif) ligand 2 (CCL2), and granulocyte-macrophage colony-stimulating factor (GM-CSF). COVID-19 can cause severe pneumonia, and neurological disorders, including stroke, the damage to the neurovascular unit, blood-brain barrier disruption, high intracranial proinflammatory cytokines, and endothelial cell damage in the brain. Mast cells are innate immune cells and also implicated in adaptive immune response, systemic inflammatory diseases, neuroinflammatory diseases, traumatic brain injury and stroke, and stress disorders. SARS-CoV-2 can activate monocytes/macrophages, dendritic cells, T cells, mast cells, neutrophils, and induce cytokine storm in the lung. COVID-19 can activate mast cells, neurons, glial cells, and endothelial cells. SARS-CoV-2 infection can cause psychological stress and neuroinflammation. In conclusion, COVID-19 can induce mast cell activation, psychological stress, cytokine storm, and neuroinflammation.

Cytokine Storm in COVID19: A Neural Hypothesis

Cytokine storm in COVID-19 is characterized by an excessive inflammatory response to SARS-CoV-2 that is caused by a dysregulated immune system of the host. We are proposing a new hypothesis that SARS-CoV-2 mediated inflammation of nucleus tractus solitarius (NTS) may be responsible for the cytokine storm in COVID 19. The inflamed NTS may result in a dysregulated cholinergic anti-inflammatory pathway and hypothalamic-pituitary-adrenal axis.