Update on neurological manifestations of COVID-19

COVID-19: Unveiling the Neuropsychiatric Maze-From Acute to Long-Term Manifestations

The SARS-CoV-2 virus has spread rapidly despite implementing strategies to reduce its transmission. The disease caused by this virus has been associated with a diverse range of symptoms, including common neurological manifestations such as dysgeusia, anosmia, and myalgias. Additionally, numerous cases of severe neurological complications associated with this disease have been reported, including encephalitis, stroke, seizures, and Guillain-Barré syndrome, among others. Given the high prevalence of neurological manifestations in this disease, the objective of this review is to analyze the mechanisms by which this virus can affect the nervous system, from its direct invasion to aberrant activation of the immune system and other mechanisms involved in the symptoms, including neuropsychiatric manifestations, to gain a better understanding of the disease and thus facilitate the search for effective therapeutic strategies.

Extracellular Vesicles: The Invisible Heroes and Villains of COVID-19 Central Neuropathology

Acknowledging the neurological symptoms of COVID-19 and the long-lasting neurological damage even after the epidemic ends are common, necessitating ongoing vigilance. Initial investigations suggest that extracellular vesicles (EVs), which assist in the evasion of the host's immune response and achieve immune evasion in SARS-CoV-2 systemic spreading, contribute to the virus's attack on the central nervous system (CNS). The pro-inflammatory, pro-coagulant, and immunomodulatory properties of EVs contents may directly drive neuroinflammation and cerebral thrombosis in COVID-19. Additionally, EVs have attracted attention as potential candidates for targeted therapy in COVID-19 due to their innate homing properties, low immunogenicity, and ability to cross the blood-brain barrier (BBB) freely. Mesenchymal stromal/stem cell (MSCs) secreted EVs are widely applied and evaluated in patients with COVID-19 for their therapeutic effect, considering the limited antiviral treatment. This review summarizes the involvement of EVs in COVID-19 neuropathology as carriers of SARS-CoV-2 or other pathogenic contents, as predictors of COVID-19 neuropathology by transporting brain-derived substances, and as therapeutic agents by delivering biotherapeutic substances or drugs. Understanding the diverse roles of EVs in the neuropathological aspects of COVID-19 provides a comprehensive framework for developing, treating, and preventing central neuropathology and the severe consequences associated with the disease.

Targeting the mammalian target of rapamycin pathway in neurological manifestations of Covid-19

The diverse and severe nature of neurological manifestations associated with coronavirus disease 2019 (Covid-19) has garnered increasing attention. Exploring the potential to decrease neurological complications in Covid-19 patients involves targeting the mammalian target of rapamycin (mTOR) pathway as a therapeutic strategy. The mTOR pathway, widely recognised for its central role in essential cellular processes like synthesising proteins, facilitating autophagy, and modulating immune responses, has implications in various neurological disorders. Drawing parallels between these disorders and the observed neurological complications in Covid-19, we present a comprehensive review on the current understanding of mTOR signalling in the context of severe acute respiratory syndrome coronavirus 2 infection and neuroinflammation.

Assessment of Cognitive and Mood Changes in Older Survivors of COVID-19: A Year's Follow-up

ABSTRACT

The long-term effects of coronavirus disease 2019 (COVID-19) infection are not fully known. In this study, we aimed to evaluate cognitive function and mood changes with 1-year follow-up in the elderly after COVID-19 disease. Ninety COVID-19 survivors and 90 healthy controls were included in the study between April 2022 and 2023. The patients were evaluated at the 1st, 6th, and 12th months for cognition, depression, and sleep quality. Cognitive function is assessed by the Montreal Cognitive Assessment (MoCA), sleep quality by the Pittsburgh Sleep Quality Index, and depression by the Yesavage Geriatric Depression Scale. COVID-19 survivors secured lower scores in certain domains of the MoCA in comparison with the controls at the first and sixth months. However, at the 12th month, no difference was observed in total MoCA ( p = 0.100), Yesavage Geriatric Depression Scale ( p = 0.503), and Pittsburgh Sleep Quality Index ( p = 0.907) between survivors and controls. Older patients who recovered from COVID-19 have lower cognitive function compared with controls up to 12 months. However, cognitive function scores were similar at the end of the first year except for memory scores.

Correlation of covid-19 and Guillain-Barré syndrome: A Mechanistic Perspective

Aims

Coronaviruses, SARS-CoV-2 particles are spherical and have proteins called spikes that stick out on the surface. COVID-19 most commonly affects the respiratory system, but various clinical manifestations on coronavirus have revealed their potential neurotropism. The neuroinvasive affinity of Coronavirus infections has been reported nearly for all the β Coronavirus infections, including MERS-CoV, SARS-CoV, HCoV-OC43 and HEV. Coronavirus invasion occurs through hypoxia injury, immune injury, ACE2, and direct infection. The pathophysiology of SARS-CoV-2 and other human Coronaviruses reveals the possible mechanisms of neurodegeneration.

Methods

A systematic literature review carried out from various search engines like Scopus, PubMed, Medline, and Elsevier for investigating the therapeutic perspective of association between Covid-19 and Guillain-Barré syndrome.

Results

SARS-CoV-2 uses angiotensin-converting enzyme 2 as its entry receptor and enters the central nervous system through a Blood-brain barrier constituted of inflammatory mediators, direct infection of the endothelial cells, or endothelial injury. Guillain-Barré syndrome is an autoimmune disease that injures and attacks the nerves in the peripheral nervous system. Studies suggest that the virus can infect peripheral neurons to cause direct damage through various mechanisms, including direct damage by cytokine-related injury, ACE2 receptors, and the sequelae of hypoxia.

Conclusion

we have discussed the possible mechanisms between neuroinvasion of SARs-cov2 and Guillain-barre syndrome.

Laryngeal sensory neuropathy caused by COVID-19: findings using laryngeal electromyography

PURPOSE

Laryngeal sensory neuropathy (LSN) is caused by a disorder of the superior laryngeal nerve or the recurrent laryngeal nerve. A diagnosis of LSN should include laryngeal electromyography (LEMG) and laryngovideostroboscopy (LVS). The aim of this study was to characterize the physical and subjective symptoms of neuropathy in patients diagnosed with LSN following COVID-19.

MATERIAL AND METHODS

Since the beginning of the COVID-19 pandemic, 6 patients who had recovered from the disease presented to us with LSN symptoms. All patients underwent laryngological and phoniatric examination, objective and subjective voice assessment, and LEMG.

RESULTS

The most common LSN symptom reported by patients was periodic hoarseness of varying severity. Other common symptoms were the sensation of a foreign body in the throat and voice fatigue. Endoscopy often showed functional abnormalities. The LSN patients could be characterized by LEMG recordings, and all showed abnormal activity of the cricothyroid (CT) muscle. The degree of EMG changes in the CT correlated moderately with the severity of dysphonia.

CONCLUSIONS

Sensory neuropathy of the larynx may be a long-lasting complication of SARS-COV-2 infection. The severity of EMG neuropathic changes in the CT muscle broadly corresponds to the severity of dysphonia.

SARS-CoV-2 Possible Etiology of Cerebral Venous Thrombosis in a Teenager: Case Report and Review of Literature

Cerebral venous thrombosis in pediatric patient has a varied etiology. The authors present the case of a teenager who, since the debut of SARS-CoV-2 infection, has accused intermittent right side hemicrania, which has become persistent in association with nausea and vomiting since the 5th day of quarantine. She was hospitalized in the 9th day since the debut. Neuroimaging revealed extended venous cerebral thrombosis affecting the right sigmoid sinus, the transverse sinus bilaterally, the confluence of the transverse sinuses and the right internal jugular vein. The evolution was favorable under anticoagulant and symptomatic treatment. Laboratory tests excluded other etiological causes for the cerebral venous thrombosis, thus the authors consider that cerebral thrombosis is a possible complication of SARS-CoV-2 infection in teenagers.

Eyelid Myokymia—a Presumed Manifestation of Coronavirus Disease 2019 (COVID-19)

The purpose of this study is to report eyelid myokymia in patients recently recovered from COVID-19 disease. A cohort of 15 patients who developed eyelid myokymia during or immediate post-recovery of systemic disease were evaluated. Demographic, clinical characteristics, effect of age, and hospitalization on the disease course were studied. The disease course was evaluated every month for 3 months period. All, except 2, patients had complete resolution of lid myokymia within 3 months of onset. Median [IQR] myokymia recovery time was 42 [31,60] days. Age and duration of hospitalization had a significant linear relationship with myokymia recovery time. Recovery was delayed by 2.64 days with every 1-year increment in age and by 6.19 days with every additional day of hospital stay. Recovery time was independent of severity of systemic disease (P = .055) and gender (P = 0.2). Eyelid myokymia can be a possible manifestation of COVID-19 recovery phase. While myokymia recovers gradually in all these patients, older age and a longer duration of hospitalization are associated with slower recovery.

COVID-19 and neurological complications: A review

Infections with viruses have detrimental effects on neurological functions, and even cause severe neurological damage. There is mounting evidence that coronaviruses (CoV) as well as SARS-CoV-2 exhibit neurotropic abilities and might cause neurological problems. Neuroinvasive viruses are not fully understood, which makes it important to investigate their impact on the nervous system. In this paper, we review research into neurological complications associated with CoV.

Morphological, cellular, and molecular basis of brain infection in COVID-19 patients

Although increasing evidence confirms neuropsychiatric manifestations associated mainly with severe COVID-19 infection, long-term neuropsychiatric dysfunction (recently characterized as part of “long COVID-19” syndrome) has been frequently observed after mild infection. We show the spectrum of cerebral impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, ranging from long-term alterations in mildly infected individuals (orbitofrontal cortical atrophy, neurocognitive impairment, excessive fatigue and anxiety symptoms) to severe acute damage confirmed in brain tissue samples extracted from the orbitofrontal region (via endonasal transethmoidal access) from individuals who died of COVID-19. In an independent cohort of 26 individuals who died of COVID-19, we used histopathological signs of brain damage as a guide for possible SARS-CoV-2 brain infection and found that among the 5 individuals who exhibited those signs, all of them had genetic material of the virus in the brain. Brain tissue samples from these five patients also exhibited foci of SARS-CoV-2 infection and replication, particularly in astrocytes. Supporting the hypothesis of astrocyte infection, neural stem cell–derived human astrocytes in vitro are susceptible to SARS-CoV-2 infection through a noncanonical mechanism that involves spike–NRP1 interaction. SARS-CoV-2–infected astrocytes manifested changes in energy metabolism and in key proteins and metabolites used to fuel neurons, as well as in the biogenesis of neurotransmitters. Moreover, human astrocyte infection elicits a secretory phenotype that reduces neuronal viability. Our data support the model in which SARS-CoV-2 reaches the brain, infects astrocytes, and consequently, leads to neuronal death or dysfunction. These deregulated processes could contribute to the structural and functional alterations seen in the brains of COVID-19 patients.

Morphological, cellular, and molecular basis of brain infection in COVID-19 patients

Although increasing evidence confirms neuropsychiatric manifestations associated mainly with severe COVID-19 infection, long-term neuropsychiatric dysfunction (recently characterized as part of "long COVID-19" syndrome) has been frequently observed after mild infection. We show the spectrum of cerebral impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, ranging from long-term alterations in mildly infected individuals (orbitofrontal cortical atrophy, neurocognitive impairment, excessive fatigue and anxiety symptoms) to severe acute damage confirmed in brain tissue samples extracted from the orbitofrontal region (via endonasal transethmoidal access) from individuals who died of COVID-19. In an independent cohort of 26 individuals who died of COVID-19, we used histopathological signs of brain damage as a guide for possible SARS-CoV-2 brain infection and found that among the 5 individuals who exhibited those signs, all of them had genetic material of the virus in the brain. Brain tissue samples from these five patients also exhibited foci of SARS-CoV-2 infection and replication, particularly in astrocytes. Supporting the hypothesis of astrocyte infection, neural stem cell-derived human astrocytes in vitro are susceptible to SARS-CoV-2 infection through a noncanonical mechanism that involves spike-NRP1 interaction. SARS-CoV-2-infected astrocytes manifested changes in energy metabolism and in key proteins and metabolites used to fuel neurons, as well as in the biogenesis of neurotransmitters. Moreover, human astrocyte infection elicits a secretory phenotype that reduces neuronal viability. Our data support the model in which SARS-CoV-2 reaches the brain, infects astrocytes, and consequently, leads to neuronal death or dysfunction. These deregulated processes could contribute to the structural and functional alterations seen in the brains of COVID-19 patients.

Nasal Microbiota, Olfactory Health, Neurological Disorders and Aging—A Review

The nasal region is one of the distinct environments for the survival of various microbiota. The human microbial niche begins to inhabit the human body right from birth, and the microbiota survive as commensals or opportunistic pathogens throughout the life of humans in their bodies in various habitats. These microbial communities help to maintain a healthy microenvironment by preventing the attack of pathogens and being involved in immune regulation. Any dysbiosis of microbiota residing in the mucosal surfaces, such as the nasal passages, guts, and genital regions, causes immune modulation and severe infections. The coexistence of microorganisms in the mucosal layers of respiratory passage, resulting in infections due to their co-abundance and interactions, and the background molecular mechanisms responsible for such interactions, need to be considered for investigation. Additional clinical evaluations can explain the interactions among the nasal microbiota, nasal dysbiosis and neurodegenerative diseases (NDs). The respiratory airways usually act as a substratum place for the microbes and can act as the base for respiratory tract infections. The microbial metabolites and the microbes can cross the blood–brain barrier and may cause NDs, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), and multiple sclerosis (MS). The scientific investigations on the potential role of the nasal microbiota in olfactory functions and the relationship between their dysfunction and neurological diseases are limited. Recently, the consequences of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) in patients with neurological diseases are under exploration. The crosstalk between the gut and the nasal microbiota is highly influential, because their mucosal regions are the prominent microbial niche and are connected to the olfaction, immune regulation, and homeostasis of the central nervous system. Diet is one of the major factors, which strongly influences the mucosal membranes of the airways, gut, and lung. Unhealthy diet practices cause dysbiosis in gut microbiota and the mucosal barrier. The current review summarizes the interrelationship between the nasal microbiota dysbiosis, resulting olfactory dysfunctions, and the progression of NDs during aging and the involvement of coronavirus disease 2019 in provoking the NDs.

Abnormal antibodies to self-carbohydrates in SARS-CoV-2-infected patients

Our immune system is critical for preventing and treating SARS-CoV-2 infections, but aberrant immune responses can have deleterious effects. While antibodies to glycans could recognize the virus and influence the clinical outcome, little is known about their roles. Using a carbohydrate antigen microarray, we profiled serum antibodies in healthy control subjects and COVID-19 patients from two separate cohorts. COVID-19 patients had numerous autoantibodies to self-glycans, including antiganglioside antibodies that can cause neurological disorders. Additionally, nearly all antiglycan IgM signals were lower in COVID-19 patients, indicating a global dysregulation of this class of antibodies. Autoantibodies to certain N-linked glycans correlated with more severe disease, as did low levels of antibodies to the Forssman antigen and ovalbumin. Collectively, this study indicates that expanded testing for antiglycan antibodies could be beneficial for clinical analysis of COVID-19 patients and illustrates the importance of including host and viral carbohydrate antigens when studying immune responses to viruses.

Non-Productive Infection of Glial Cells with SARS-CoV-2 in Hamster Organotypic Cerebellar Slice Cultures

The numerous neurological syndromes associated with COVID-19 implicate an effect of viral pathogenesis on neuronal function, yet reports of direct SARS-CoV-2 infection in the brain are conflicting. We used a well-established organotypic brain slice culture to determine the permissivity of hamster brain tissues to SARS-CoV-2 infection. We found levels of live virus waned after inoculation and observed no evidence of cell-to-cell spread, indicating that SARS-CoV-2 infection was non-productive. Nonetheless, we identified a small number of infected cells with glial phenotypes; however, no evidence of viral infection or replication was observed in neurons. Our data corroborate several clinical studies that have assessed patients with COVID-19 and their association with neurological involvement.

Psychotropics and COVID-19: An analysis of safety and prophylaxis

The use of psychotropics during the COVID-19 pandemic has raised two questions, in order of importance: first, what changes should be made to pharmacological treatments prescribed to mental health patients? Secondly, are there any positive side effects of these substances against SARS-CoV-2? Our aim was to analyze usage safety of psychotropics during COVID-19; therefore, herein, we have studied: (i) the risk of symptomatic complications of COVID-19 associated with the use of these drugs, notably central nervous system activity depression, QTc interval enlargement and infectious and thromboembolic complications; (ii) the risk of mistaking the iatrogenic impact of psychotropics with COVID-19 symptoms, causing diagnostic error. Moreover, we provided a summary of the different information available today for these risks, categorized by mental health disorder, for the following: schizophrenia, bipolar disorder, anxiety disorder, ADHD, sleep disorders and suicidal risk. The matter of psychoactive substance use during the pandemic is also analyzed in this paper, and guideline websites and publications for psychotropic treatments in the context of COVID-19 are referenced during the text, so that changes on those guidelines and eventual interaction between psychotropics and COVID-19 treatment medication can be reported and studied. Finally, we also provide a literature review of the latest known antiviral properties of psychotropics against SARS-CoV-2 as complementary information.

Common Inflammatory Mechanisms in COVID-19 and Parkinson's Diseases: The Role of Microbiome, Pharmabiotics and Postbiotics in Their Prevention

In the last decade, metagenomic studies have shown the key role of the gut microbiome in maintaining immune and neuroendocrine systems. Malfunction of the gut microbiome can induce inflammatory processes, oxidative stress, and cytokine storm. Dysfunction of the gut microbiome can be caused by short-term (virus infection and other infectious diseases) or long-term (environment, nutrition, and stress) factors. Here, we reviewed the inflammation and oxidative stress in neurodegenerative diseases and coronavirus infection (COVID-19). Here, we reviewed the renin-angiotensin-aldosterone system (RAAS) involved in the processes of formation of oxidative stress and inflammation in viral and neurodegenerative diseases. Moreover, the coronavirus uses ACE2 receptors of the RAAS to penetrate human cells. The coronavirus infection can be the trigger for neurodegenerative diseases by dysfunction of the RAAS. Pharmabiotics, postbiotics, and next-generation probiotics, are considered as a means to prevent oxidative stress, inflammatory processes, neurodegenerative and viral diseases through gut microbiome regulation.

Molecular Mechanisms of SARS-CoV-2/COVID-19 Pathogenicity on the Central Nervous System: Bridging Experimental Probes to Clinical Evidence and Therapeutic Interventions

The coronavirus disease 2019 (COVID-19) pandemic, induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has dramatically impacted the global healthcare systems, constantly challenging both research and clinical practice. Although it was initially believed that the SARS-CoV-2 infection is limited merely to the respiratory system, emerging evidence indicates that COVID-19 affects multiple other systems including the central nervous system (CNS). Furthermore, most of the published clinical studies indicate that the confirmed CNS inflammatory manifestations in COVID-19 patients are meningitis, encephalitis, acute necrotizing encephalopathy, acute transverse myelitis, and acute disseminated encephalomyelitis. In addition, the neuroinflammation along with accelerated neurosenescence and susceptible genetic signatures in COVID-19 patients might prime the CNS to neurodegeneration and precipitate the occurrence of neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. Thus, this review provides a critical evaluation and interpretive analysis of existing published preclinical as well as clinical studies on the key molecular mechanisms modulating neuroinflammation and neurodegeneration induced by the SARS-CoV-2. In addition, the essential age- and gender-dependent impacts of SARS-CoV-2 on the CNS of COVID-19 patients are also discussed.

Hamster organotypic modeling of SARS-CoV-2 lung and brainstem infection

SARS-CoV-2 has caused a global pandemic of COVID-19 since its emergence in December 2019. The infection causes a severe acute respiratory syndrome and may also spread to central nervous system leading to neurological sequelae. We have developed and characterized two new organotypic cultures from hamster brainstem and lung tissues that offer a unique opportunity to study the early steps of viral infection and screening antivirals. These models are not dedicated to investigate how the virus reaches the brain. However, they allow validating the early tropism of the virus in the lungs and demonstrating that SARS-CoV-2 could infect the brainstem and the cerebellum, mainly by targeting granular neurons. Viral infection induces specific interferon and innate immune responses with patterns specific to each organ, along with cell death by apoptosis, necroptosis, and pyroptosis. Overall, our data illustrate the potential of rapid modeling of complex tissue-level interactions during infection by a newly emerged virus.

A Review on SARS-CoV-2-Induced Neuroinflammation, Neurodevelopmental Complications, and Recent Updates on the Vaccine Development

Coronavirus disease 2019 (COVID-19) is a devastating viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The incidence and mortality of COVID-19 patients have been increasing at an alarming rate. The mortality is much higher in older individuals, especially the ones suffering from respiratory distress, cardiac abnormalities, renal diseases, diabetes, and hypertension. Existing evidence demonstrated that SARS-CoV-2 makes its entry into human cells through angiotensin-converting enzyme 2 (ACE-2) followed by the uptake of virions through cathepsin L or transmembrane protease serine 2 (TMPRSS2). SARS-CoV-2-mediated abnormalities in particular cardiovascular and neurological ones and the damaged coagulation systems require extensive research to develop better therapeutic modalities. As SARS-CoV-2 uses its S-protein to enter into the host cells of several organs, the S-protein of the virus is considered as the ideal target to develop a potential vaccine. In this review, we have attempted to highlight the landmark discoveries that lead to the development of various vaccines that are currently under different stages of clinical progression. Besides, a brief account of various drug candidates that are being tested to mitigate the burden of COVID-19 was also covered. Further, in a dedicated section, the impact of SARS-CoV-2 infection on neuronal inflammation and neuronal disorders was discussed. In summary, it is expected that the content covered in this article help to understand the pathophysiology of COVID-19 and the impact on neuronal complications induced by SARS-CoV-2 infection while providing an update on the vaccine development.

Cranial nerve involvement in COVID-19

Introduction

The COVID-19 disease emerged in Wuhan province of China in November 2019 and spread across the world in a short time, resulting in a pandemic. The first case in Turkey was detected on March 11, 2020. The aim of the current study was to reveal the effects of COVID-19 on cranial nerves by monitoring people infected with the disease based on repeated examinations and surveys.

Material and method

The data of 356 patients with a positive COVID-19 polymerase chain reaction (PCR) test who received treatment between June 2020 and August 2020 in our hospital were prospectively evaluated after the study was approved by the relevant ethics committee.

Results

Of the 356 patients included in the study, 47 under the age of 18 years were excluded due to their unreliable examination and anamnesis findings. In addition, seven patients that died while in hospital were excluded from the study due to the lack of examination and survey records during their hospitalization. The data of the remaining 302 patients were statistically analyzed. Symptoms of cranial nerve involvement were observed in 135 patients.

Conclusion

The COVID-19 disease caused by the SARS-CoV2 virus commonly results in cranial nerve symptoms. The fact that these findings are more common and severe in COVID-19 than previous SARS and MERS outbreaks suggests that it has a more neurotrophic and more aggressive neuroinvasion. While the negative effects of the virus on sensory functions resulting from cranial nerve involvement are evident, motor functions are rarely affected.

Vagus nerve neuropathy related to SARS COV-2 infection

A 38-year-old woman with confirmed SARS-CoV-2 infection developed dysphagia to both solids and liquids. A fiberoptic nasolaryngoscopy and a videofluoroscopy swallowing study showed right vocal cord paresis, tenth cranial nerve neuropathy, as well as oral, hypopharynx, and supraglottic hypoesthesia. Orotracheal intubation was not required. The patient was fully recovered after undergoing a multidisciplinary rehabilitation program that included speech and deglutition therapy.

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

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

Nervous System Involvement in COVID-19: a Review of the Current Knowledge

The current pandemic of the new human coronavirus (CoV), i.e., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created an urgent global condition. The disease, termed coronavirus disease 2019 (COVID-19), is primarily known as a respiratory tract infection. Although SARS-CoV-2 directly invades the lungs, COVID-19 is a complex multi-system disease with varying degrees of severity and affects several human systems including the cardiovascular, respiratory, gastrointestinal, neurological, hematopoietic, and immune systems. From the existing data, most COVID-19 cases develop a mild disease typically presented with fever and respiratory illness. However, in some patients, clinical evidence suggests that COVID-19 might progress to acute respiratory distress syndrome (ARDS), multi-organ dysfunction, and septic shock resulting in a critical condition. Likewise, specific organ dysfunction seems to be related to the disease complication, worsens the condition, and increases the lethality of COVID-19. The neurological manifestations in association with disease severity and mortality have been reported in COVID-19 patients. Despite the continuously increasing reports of the neurological symptoms of SARS-CoV-2, our knowledge about the possible routes of nervous system involvement associated with COVID-19 is limited. Herein, we will primarily describe the critical aspects and clinical features of SARS-CoV-2 related to nervous system impairment and then discuss possible routes of SARS-CoV-2 nervous system involvement based on the current evidence.

The impact of SARS-Cov-2 on the Nervous system and Mental Health

The World Health Organization declared the pandemic situation caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) in March 2020, but the detailed pathophysiological mechanisms of Coronavirus disease 2019 (COVID-19) are not yet completely understood. Therefore, to date, few therapeutic options are available for patients with mild-moderate or serious disease. In addition to systemic and respiratory symptoms, several reports have documented various neurological symptoms and impairments of mental health. The current review aims to provide the available evidence about the effects of SARS-CoV-2 infection on mental health. The present data suggest that SARS-CoV-2 produces a wide range of impairments and disorders of the brain. However, a limited number of studies investigated the neuroinvasive potential of SARS-CoV-2. Although the main features and outcomes of COVID-19 are linked to severe acute respiratory illness, the possible damages on the brain should be considered, too.

Comprehensive Review on Neuro-COVID-19 Pathophysiology and Clinical Consequences

Aside from the respiratory distress as the predominant clinical presentation of SARS-CoV-2 infection, various neurological complications have been reported with the infection during the ongoing pandemic, some of which cause serious morbidity and mortality. Herein, we gather the latest anatomical evidence of the virus's presence within the central nervous system. We then delve into the possible SARS-CoV-2 entry routes into the neurological tissues, with the hematogenous and the neuronal routes as the two utmost passage routes into the nervous system. We then give a comprehensive review of the neurological manifestations of the SARS-CoV-2 invasion in both the central and peripheral nervous system and its underlying pathophysiology via investigating large studies in the field and case reports in cases of study scarcity.

Emerging COVID-19 Neurological Manifestations: Present Outlook and Potential Neurological Challenges in COVID-19 Pandemic

The unremitting coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) marked a year-long phase of public health adversaries and has severely compromised healthcare globally. Early evidence of COVID-19 noted its impact on the pulmonary and cardiovascular functions, while multiple studies in recent time shed light on its substantial neurological complications, though a comprehensive understanding of the cause(s), the mechanism(s), and their neuropathological outcomes is scarce. In the present review, we conferred evidence of neurological complications in COVID-19 patients and shed light on the SARS-CoV-2 infection routes including the hematogenous, direct/neuronal, lymphatic tissue or cerebrospinal fluid, or infiltration through infected immune cells, while the underlying mechanism of SARS-CoV-2 invasion to the central nervous system (CNS) was also discussed. In an up-to-date manner, we further reviewed the impact of COVID-19 in developing diverse neurologic manifestations associated with CNS, peripheral nervous system (PNS), skeletal muscle, and also pre-existing neurological diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, epilepsy, and myasthenia gravis. Furthermore, we discussed the involvement of key factors including age, sex, comorbidity, and disease severity in exacerbating the neurologic manifestations in COVID-19 patients. An outlook of present therapeutic strategies and state of existing challenges in COVID-19 management was also accessed. Conclusively, the present report provides a comprehensive review of COVID-19-related neurological complications and emphasizes the need for their early clinical management in the ongoing COVID-19 pandemic.

Encephalopathy at admission predicts adverse outcomes in patients with SARS-CoV-2 infection

Aims

To determine if neurologic symptoms at admission can predict adverse outcomes in patients with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2).

Methods

Electronic medical records of 1053 consecutively hospitalized patients with laboratory‐confirmed infection of SARS‐CoV‐2 from one large medical center in the USA were retrospectively analyzed. Univariable and multivariable Cox regression analyses were performed with the calculation of areas under the curve (AUC) and concordance index (C‐index). Patients were stratified into subgroups based on the presence of encephalopathy and its severity using survival statistics. In sensitivity analyses, patients with mild/moderate and severe encephalopathy (defined as coma) were separately considered.

Results

Of 1053 patients (mean age 52.4 years, 48.0% men [n = 505]), 35.1% (n = 370) had neurologic manifestations at admission, including 10.3% (n = 108) with encephalopathy. Encephalopathy was an independent predictor for death (hazard ratio [HR] 2.617, 95% confidence interval [CI] 1.481–4.625) in multivariable Cox regression. The addition of encephalopathy to multivariable models comprising other predictors for adverse outcomes increased AUCs (mortality: 0.84–0.86, ventilation/ intensive care unit [ICU]: 0.76–0.78) and C‐index (mortality: 0.78 to 0.81, ventilation/ICU: 0.85–0.86). In sensitivity analyses, risk stratification survival curves for mortality and ventilation/ICU based on severe encephalopathy (n = 15) versus mild/moderate encephalopathy (n = 93) versus no encephalopathy (n = 945) at admission were discriminative (p < 0.001).

Conclusions

Encephalopathy at admission predicts later progression to death in SARS‐CoV‐2 infection, which may have important implications for risk stratification in clinical practice.

COVID-19, Neuropathology, and Aging: SARS-CoV-2 Neurological Infection, Mechanism, and Associated Complications

The spectrum of health complications instigated by coronavirus disease 2019 (COVID-19, caused by the novel severe acute respiratory syndrome coronavirus 2 or SARS-CoV-2) pandemic has been diverse and complex. Besides the evident pulmonary and cardiovascular threats, accumulating clinical data points to several neurological complications, which are more common in elderly COVID-19 patients. Recent pieces of evidence have marked events of neuro infection and neuroinvasion, producing several neurological complications in COVID-19 patients; however, a systematic understanding of neuro-pathophysiology and manifested neurological complications, more specifically in elderly COVID-19 patients is largely elusive. Since the elderly population gradually develops neurological disorders with aging, COVID-19 inevitably poses a higher risk of neurological manifestations to the aged patients. In this report, we reviewed SARS-CoV-2 infection and its role in neurological manifestations with an emphasis on the elderly population. We reviewed neuropathological events including neuroinfection, neuroinvasion, and their underlying mechanisms affecting neuromuscular, central- and peripheral- nervous systems. We further assessed the imminent neurological challenges in the COVID-19 exposed population, post-SARS-CoV-2-infection. Given the present state of clinical preparedness, the emerging role of AI and machine learning was also discussed concerning COVID-19 diagnostics and its management. Taken together, the present review summarizes neurological outcomes of SARS-CoV-2 infection and associated complications, specifically in elderly patients, and underlines the need for their clinical management in advance.

Neurological manifestations and neuroimaging findings in patients with SARS-CoV2-a systematic review

BACKGROUND

The COVID-19 pandemic has drastically affected everyone in a hit or miss manner. Since it began, evidence of the neuro-invasive potential of the virus has been intensifying significantly. Several pathways have been hypothesized to elucidate the neurotropic nature of SARS-CoV2. It is the need of the hour to collect vital information.

OBJECTIVE

To evaluate and correlate the neuro-radiological and neurological manifestations in patients diagnosed with SARS-CoV2.To identify neuro-invasive pathways of COVID infection.

METHODS

Relevant studies were identified through four databases-the Cochrane Library, PubMed, Science Direct, and Web of Science. These were searched using relevant keywords-"COVID-19," "SARS-CoV2," "neurological manifestations," "neuroimaging," "CT," and "MRI." Relevant articles were screened according to a pre-defined inclusion and exclusion criteria from December 2019 to August 2020.

RESULTS

Our review included a total of 63 full text publications with 584 patients, composed mainly of observational studies, case reports, and case series. The most common neurological manifestations associated with COVID-19 were altered mental status, stroke, and paralysis. About 17.85% patients who underwent neuroimaging were found to be having ischemic changes suggestive of a stroke. This was followed by hemorrhagic changes as the second most common finding. The most commonly involved vessel was the Middle Cerebral Artery. Besides stroke, we found that SARS-CoV2 could be the cause for new-onset seizures, Guillain-Barre Syndrome, encephalitis, and many other severe neurological diseases.

CONCLUSION

The information that we have obtained so far will prove dynamic to healthcare providers working against the COVID-19 pandemic. It is necessary to be aware of these atypical neurological findings for the early diagnosis and treatment of COVID-19 infected patients. However, to completely understand the connection between SARS-CoV2 and the nervous system, further research is necessary.

Botulism during SARS-CoV-2 pandemic: The importance of differential diagnoses

Botulism is a neuroparalytic syndrome caused by a neurotoxin produced by Clostridium botulinum. We describe a patient with neurological symptoms associated with intoxication by Clostridium botulinum and infection by SARSCoV2. This report underlines that it is mandatory, even in case of SARS-CoV-2 positivity, to investigate all the causes of a clinical pattern.

COVID-19 and Parkinson's disease: Defects in neurogenesis as the potential cause of olfactory system impairments and anosmia

Anosmia, a neuropathogenic condition of loss of smell, has been recognized as a key pathogenic hallmark of the current pandemic SARS-CoV-2 infection responsible for COVID-19. While the anosmia resulting from olfactory bulb (OB) pathology is the prominent clinical characteristic of Parkinson's disease (PD), SARS-CoV-2 infection has been predicted as a potential risk factor for developing Parkinsonism-related symptoms in a significant portion of COVID-19 patients and survivors. SARS-CoV-2 infection appears to alter the dopamine system and induce the loss of dopaminergic neurons that have been known to be the cause of PD. However, the underlying biological basis of anosmia and the potential link between COVID-19 and PD remains obscure. Ample experimental studies in rodents suggest that the occurrence of neural stem cell (NSC) mediated neurogenesis in the olfactory epithelium (OE) and OB is important for olfaction. Though the occurrence of neurogenesis in the human forebrain has been a subject of debate, considerable experimental evidence strongly supports the incidence of neurogenesis in the human OB in adulthood. To note, various viral infections and neuropathogenic conditions including PD with olfactory dysfunctions have been characterized by impaired neurogenesis in OB and OE. Therefore, this article describes and examines the recent reports on SARS-CoV-2 mediated OB dysfunctions and defects in the dopaminergic system responsible for PD. Further, the article emphasizes that COVID-19 and PD associated anosmia could result from the regenerative failure in the replenishment of the dopaminergic neurons in OB and olfactory sensory neurons in OE.

Alterations of frontal-temporal gray matter volume associate with clinical measures of older adults with COVID-19

COVID-19, the infectious disease caused by the most recently discovered severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a global pandemic. It dramatically affects people's health and daily life. Neurological complications are increasingly documented for patients with COVID-19. However, the effect of COVID-19 on the brain is less studied, and existing quantitative neuroimaging analyses of COVID-19 were mainly based on the univariate voxel-based morphometry analysis (VBM) that requires corrections for a large number of tests for statistical significance, multivariate approaches that can reduce the number of tests to be corrected have not been applied to study COVID-19 effect on the brain yet. In this study, we leveraged source-based morphometry (SBM) analysis, a multivariate extension of VBM, to identify changes derived from computed tomography scans in covarying gray matter volume patterns underlying COVID-19 in 120 neurological patients (including 58 cases with COVID-19 and 62 patients without COVID-19 matched for age, gender and diseases). SBM identified that lower gray matter volume (GMV) in superior/medial/middle frontal gyri was significantly associated with a higher level of disability (modified Rankin Scale) at both discharge and six months follow-up phases even when controlling for cerebrovascular diseases. GMV in superior/medial/middle frontal gyri was also significantly reduced in patients receiving oxygen therapy compared to patients not receiving oxygen therapy. Patients with fever presented significant GMV reduction in inferior/middle temporal gyri and fusiform gyrus compared to patients without fever. Patients with agitation showed GMV reduction in superior/medial/middle frontal gyri compared to patients without agitation. Patients with COVID-19 showed no significant GMV differences from patients without COVID-19 in any brain region. Results suggest that COVID-19 may affect the frontal-temporal network in a secondary manner through fever or lack of oxygen.

SARS-CoV-2 Infection in Pregnant Women: Neuroimmune-Endocrine Changes at the Maternal-Fetal Interface

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has devastating effects on the population worldwide. Given this scenario, the extent of the impact of the disease on more vulnerable individuals, such as pregnant women, is of great concern. Although pregnancy may be a risk factor in respiratory virus infections, there are no considerable differences regarding COVID-19 severity observed between pregnant and nonpregnant women. In these circumstances, an emergent concern is the possibility of neurodevelopmental and neuropsychiatric harm for the offspring of infected mothers. Currently, there is no stronger evidence indicating vertical transmission of SARS-CoV-2; however, the exacerbated inflammatory response observed in the disease could lead to several impairments in the offspring's brain. Furthermore, in the face of historical knowledge on possible long-term consequences for the progeny's brain after infection by viruses, we must consider that this might be another deleterious facet of COVID-19. In light of neuroimmune interactions at the maternal-fetal interface, we review here the possible harmful outcomes to the offspring brains of mothers infected by SARS-CoV-2.

COVID-19 and emerging spinal cord complications: A systematic review

Background

: Spinal cord complications associated with coronavirus infectious disease of 2019 (COVID-19) are being widely reported. The purpose of this systematic review was to summarize so far available pieces of evidence documenting de novo novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) mediated spinal cord demyelinating diseases. Indeed, the spinal demyelinating disorders that have been reported in those patients who have suffered from COVID-19 rather than on the people already living with diagnosed or undiagnosed primary demyelinating disorders.

Methods

: We used the existing PRISMA consensus statement. Data were collected from PubMed, NIH Litcovid, EMBASE and Cochrane library databases, as well as Pre-print servers (medRxiv, bioRxiv, and pre-preints.org), until September 10, 2020, using pre-specified searching strategies.

Results

: The 21 selected articles were all case reports and included 11 (52%) men and 10 (48%) women. The mean age was of 46.7 ± 18.0. The neurological manifestations included weakness, sensory deficit, autonomic dysfunction and ataxia. In most cases, elevated cerebrospinal fluid protein as well as lymphocytic pleocytosis were found. SARS-CoV-2 was detected in five (24%) patients, meanwhile in 13 (62%) patients, the testing was negative. Testing was not performed in two cases and, in one, data were unavailable. Nearly half of the cases (N = 9) were associated with isolated long extensive transverse myelitis (LETM), whereas a combination of both LETM and patchy involvement was found in two. Only five patients had isolated short segment involvement and two patchy involvement. Furthermore, concomitant demyelination of both brain and spine was reported in six patients. Concerning the prognosis, most of the patients improved and the mortality rate was low (N = 2, <10%).

Conclusion

: Spinal cord demyelination should be added to the plethora of immune mediated neurologic complications associated with COVID-19.

COVID-19-Related Neuropsychiatric Symptoms in Patients With Alcohol Abuse Conditions During the SARS-CoV-2 Pandemic: A Retrospective Cohort Study Using Real World Data From Electronic Health Records of a Tertiary Hospital

Patients with an alcohol abuse disorder exhibit several medical characteristics and social determinants, which suggest a greater vulnerability to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and a worse course of the coronavirus disease 2019 (COVID-19) once infected. During the first wave of the COVID-19, most of the countries have register an increase in alcohol consumption. However, studies on the impact of alcohol addiction on the risk of COVID-19 infection are very scarce and inconclusive. This research offers a descriptive observational retrospective cohort study using real world data obtained from the Electronic Health Records. We found that patients with a personal history of alcohol abuse were 8% more likely to extend their hospitalization length of stay for 1 day (95% CI = 1.04–1.12) and 15% more likely to extend their Intensive Care Unit (ICU) length of stay (95% CI = 1.01–1.30). They were also 5.47 times more at risk of needing an ICU admission (95% CI = 1.61–18.57) and 3.54 times (95% CI = 1.51–8.30) more at risk of needing a respirator. Regarding COVID-19 symptoms, patients with a personal history of alcohol abuse were 91% more likely of exhibiting dyspnea (95% CI = 1.03–3.55) and 3.15 times more at risk of showing at least one neuropsychiatric symptom (95% CI = 1.61–6.17). In addition, they showed statistically significant differences in the number of neuropsychiatric symptoms developed during the COVID-19 infection. Therefore, we strongly recommend to warn of the negative consequences of alcohol abuse over COVID-19 complications. For this purpose. Clinicians should systematically assess history of alcohol issues and drinking habits in all patients, especially for those who seek medical advice regarding COVID-19 infection, in order to predict its severity of symptoms and potential complications. Moreover, this information should be included, in a structured field, into the Electronic Health Record to facilitate the automatic extraction of data, in real time, useful to evaluate the decision-making process in a dynamic context.

Cognitive assessment in asymptomatic COVID-19 subjects

Neurological features of COVID-19 have been reported in addition to the respiratory manifestations, but cognitive dysfunction has been scarcely described. And cognitive assessment has not been studied in asymptomatic subjects. We compared the cognitive assessment scores between asymptomatic SARS-CoV-2 infected subjects with that of controls to detect mild cognitive impairment by the Montreal Cognitive Assessment test. Asymptomatic COVID-19 subjects secured lower scores in certain domains of the MoCA in comparison with the controls. The domains were visuoperception (2.4 ± 0.7 vs2.8 ± 0.7, p = 0.032), naming (3.6 ± 0.5 vs3.9 ± 0.2, p = 0.016) and fluency (0.9 ± 0.6 vs1.6 ± 0.7, p =  < 0.001). Also, older aged COVID-19 positive subjects scored lower in the MoCA when compared to the younger people. Our study shows that even otherwise asymptomatic COVID-19 subjects have cognitive deficits in certain subdomains and suggests the need for a detailed psychometric assessment especially in the elderly population.

SUPPLEMENTARY INFORMATION

The online version of this article (10.1007/s13337-021-00663-w).

[Clinical and anatomical features of SARS-COV-2 with acute hemorrhagic necrotizing encephalopathy]

Autopsy material and medical history were studied and analyzed in a 20-year-old male patient who had died from COVID-19 infection with the development of acute SARS-CoV-2-associated hemorrhagic necrotizing encephalopathy in adults with obvious endothelial dysfunction confirmed by virological examination of the autopsy material. In this case, the brain structures displayed the main found histopathologic signs: widespread vasculitis (endotheliitis) with varying degrees of segmental and total endothelial destruction; thrombosis mainly of the vessels of the microcirculatory bed; parenchymal hemorrhagic necrosis and inflammation (encephalitis); severe necrobiotic damage to neurons. Cerebrovascular immune damages and hypercoagulable states, which were observed in some acute viral neuroinfections, are the basis for the neurological complications of COVID-19. In this case of bicausal diagnosis (the presence of a comorbidity), the primary disease contributed to the acute progression of the background disease (secondary infiltrative tuberculosis with the development of specific pleuritis and pneumothorax with the addition of acute bilateral focal confluent bronchopneumonia with a history of undifferentiated immunodeficiency syndrome. Emphasis is laid on the possibility and importance of involving the brain structures in the process in COVID-19 for the timely diagnosis of emerging neurological disorders. A brief literature review is given.

Infection Mechanism of SARS-COV-2 and Its Implication on the Nervous System

In late December 2019, multiple atypical pneumonia cases resulted in severe acute respiratory syndrome caused by a pathogen identified as a novel coronavirus SARS-CoV-2. The most common coronavirus disease 2019 (COVID-19) symptoms are pneumonia, fever, dry cough, and fatigue. However, some neurological complications following SARS-CoV-2 infection include confusion, cerebrovascular diseases, ataxia, hypogeusia, hyposmia, neuralgia, and seizures. Indeed, a growing literature demonstrates that neurotropism is a common feature of coronaviruses; therefore, the infection mechanisms already described in other coronaviruses may also be applicable for SARS-CoV-2. Understanding the underlying pathogenetic mechanisms in the nervous system infection and the neurological involvement is essential to assess possible long-term neurological alteration of COVID-19. Here, we provide an overview of associated literature regarding possible routes of COVID-19 neuroinvasion, such as the trans-synapse-connected route in the olfactory pathway and peripheral nerve terminals and its neurological implications in the central nervous system.

Targeting Neurological Manifestations of Coronaviruses by Candidate Phytochemicals: A Mechanistic Approach

The novel coronavirus 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made a wide range of manifestations. In this regard, growing evidence is focusing on COVID-19 neurological associations; however, there is a lack of established pathophysiological mechanisms and related treatments. Accordingly, a comprehensive review was conducted, using electronic databases, including PubMed, Scopus, Web of Science, and Cochrane, along with the author's expertize in COVID-19 associated neuronal signaling pathways. Besides, potential phytochemicals have been provided against neurological signs of COVID-19. Considering a high homology among SARS-CoV, Middle East Respiratory Syndrome and SARS-CoV-2, revealing their precise pathophysiological mechanisms seems to pave the road for the treatment of COVID-19 neural manifestations. There is a complex pathophysiological mechanism behind central manifestations of COVID-19, including pain, hypo/anosmia, delirium, impaired consciousness, pyramidal signs, and ischemic stroke. Among those dysregulated neuronal mechanisms, neuroinflammation, angiotensin-converting enzyme 2 (ACE2)/spike proteins, RNA-dependent RNA polymerase and protease are of special attention. So, employing multi-target therapeutic agents with considerable safety and efficacy seems to show a bright future in fighting COVID-19 neurological manifestations. Nowadays, natural secondary metabolites are highlighted as potential multi-target phytochemicals in combating several complications of COVID-19. In this review, central pathophysiological mechanisms and therapeutic targets of SARS-CoV-2 has been provided. Besides, in terms of pharmacological mechanisms, phytochemicals have been introduced as potential multi-target agents in combating COVID-19 central nervous system complications.

Case Report and Literature Review: COVID-19 and status epilepticus in Dyke-Davidoff-Masson syndrome

Dyke-Davidoff-Masson syndrome (DMMS) is a non-inherited rare condition with a clinical constellation of hemiparesis/hemiplegia, facial asymmetry, intellectual disability, and epilepsy. The radiological features can be including unilateral cerebral atrophy, calvarial thickening, and hyper pneumatization of the paranasal sinuses. The condition can either be congenital or acquired. The presentation usually occurs during childhood or early adolescents, but there have been adult cases reported. Here we report a 48-year-old male who was a known poorly controlled epileptic that contracted SARS-CoV-2 with subsequently developed status epilepticus and, when worked up, was shown to have features of DDMS. This case is unique as the patient had hemiatrophy and epilepsy but managed to lead a normal, physically demanding, and high functioning academic career and presented late in life. Perhaps only due to coronavirus disease 2019 (COVID-19) was this diagnosis picked up. This report contains a case presenting atypical DDMS in status epilepticus and COVID -19 plus other complications. From our knowledge, this is the first case presenting these comorbidities reported to the medical literature.

Could Artesunate Have a Positive Effect on the Neurological Complications Related to Infection When It Is Used in the Treatment of COVID-19?

Artesunate is a safe noncytotoxic drug with low side effects which is used in the treatment of chloroquine-resistant malaria. In addition to being an antimalarial drug, artesunate also has immunomodulatory, anticarcinogenic, and antiviral activity. There are in vivo and in vitro studies reporting that artesunate may have a positive effect on the treatment of COVID-19. Artesunate may be effective based on its effect on the anti-inflammatory activity, chloroquine-like endocytosis inhibition mechanism, and nuclear factor kappa B (NF-κB) signal pathway. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may cause neurological complications in addition to targeting the respiratory system. In this study, we have discussed the possible neuroprotective action mechanisms of artesunate. We think that systemic and intranasal topical artesunate administration may have a positive effect on neurological complications resulting from COVID-19.

Neuroimaging findings of brain MRI and CT in patients with COVID-19: A systematic review and meta-analysis

PURPOSE

To comprehensively evaluate the incidences of abnormal neuroimaging findings in patients with COVID-19 via a systematic review and meta-analysis.

METHOD

PubMed-MEDLINE and EMBASE were searched for original articles reporting imaging findings of the brain in adult patients with COVID-19 between January 1, 2020 and October 9, 2020. Abnormal neuroimaging findings were categorized as (1) cerebral microhemorrhages, (2) acute spontaneous intracranial hemorrhage (ICH), (3) acute to subacute infarcts, and (4) encephalitis or encephalopathy. Pooled incidences of neuroimaging findings were assessed using random-effects modeling. Between-study heterogeneity was explored by using the χ2 statistic for pooled incidences and the inconsistency index I2. The quality of the studies was evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies. Subgroup meta-regression analysis was performed to identify potential sources of heterogeneity.

RESULTS

Twenty-one eligible papers, including 2125 patients, were identified. The pooled incidences of cerebral microhemorrhages, acute spontaneous ICH, acute/subacute infarcts, and encephalitis/encephalopathy were 6.9 % (95 % confidence interval [CI], 4.9 %-8.9 %), 5.4 % (95 % CI, 3.1 %-7.6 %), 24.0 % (95 % CI, 16.1 %-31.8 %), and 3.3 % (95 % CI, 1.9 %-4.7 %), respectively. Substantial heterogeneities were noted for all neuroimaging findings (I2 = 87 %-97 %). Significant publication biases were present in the pooled incidences. In the subgroup meta-regression analysis, patients with mean or median ages over 65 years showed a significantly lower incidence of encephalitis/encephalopathy (P < 0.001). Furthermore, studies reported that patients in ICU had significantly higher incidences of cerebral microhemorrhages (P < 0.001) and encephalitis/encephalopathy (P < 0.001).

CONCLUSIONS

Considerable incidences of abnormal neuroimaging findings have been reported in patients with COVID-19. Acute to subacute cerebral infarction was the most prevalent neuroimaging finding.

Pathogenesis-directed therapy of 2019 novel coronavirus disease

The 2019 novel coronavirus disease (COVID-19) now is considered a global public health emergency. One of the unprecedented challenges is defining the optimal therapy for those patients with severe pneumonia and systemic manifestations of COVID-19. The optimal therapy should be largely based on the pathogenesis of infections caused by this novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the onset of COVID-19, there have been many prepublications and publications reviewing the therapy of COVID-19 as well as many prepublications and publications reviewing the pathogenesis of SARS-CoV-2. However, there have been no comprehensive reviews that link COVID-19 therapies to the pathogenic mechanisms of SARS-CoV-2. To link COVID-19 therapies to pathogenic mechanisms of SARS-CoV-2, we performed a comprehensive search through MEDLINE, PubMed, medRxiv, EMBASE, Scopus, Google Scholar, and Web of Science using the following keywords: COVID-19, SARS-CoV-2, novel 2019 coronavirus, pathology, pathologic, pathogenesis, pathophysiology, coronavirus pneumonia, coronavirus infection, coronavirus pulmonary infection, coronavirus cardiovascular infection, coronavirus gastroenteritis, coronavirus autopsy findings, viral sepsis, endotheliitis, thrombosis, coagulation abnormalities, immunology, humeral immunity, cellular immunity, inflammation, cytokine storm, superantigen, therapy, treatment, therapeutics, immune-based therapeutics, antiviral agents, respiratory therapy, oxygen therapy, anticoagulation therapy, adjuvant therapy, and preventative therapy. Opinions expressed in this review also are based on personal experience as clinicians, authors, peer reviewers, and editors. This narrative review linking COVID-19 therapies with pathogenic mechanisms of SARS-CoV-2 has resulted in six major therapeutic goals for COVID-19 therapy based on the pathogenic mechanisms of SARS-CoV-2. These goals are listed below: 1. The first goal is identifying COVID-19 patients that require both testing and therapy. This is best accomplished with a COVID-19 molecular test from symptomatic patients as well as determining the oxygen saturation in such patients with a pulse oximeter. Whether a symptomatic respiratory illness is COVID-19, influenza, or another respiratory pathogen, an oxygen saturation less than 90% means that the patient requires medical assistance. 2. The second goal is to correct the hypoxia. This goal generally requires hospitalization for oxygen therapy; other respiratory-directed therapies such as prone positioning or mechanical ventilation are often used in the attempt to correct hypoxemia due to COVID-19. 3. The third goal is to reduce the viral load of SARS-CoV-2. Ideally, there would be an oral antiviral agent available such as seen with the use of oseltamivir phosphate for influenza. This oral antiviral agent should be taken early in the course of SARS-CoV-2 infection. Such an oral agent is not available yet. Currently, two options are available for reducing the viral load of SARS-CoV-2. These are post-Covid-19 plasma with a high neutralizing antibody titer against SARS-CoV-2 or intravenous remdesivir; both options require hospitalization. 4. The fourth goal is to identify and address the hyperinflammation phase often seen in hospitalized COVID-19 patients. Currently, fever with an elevated C-reactive protein is useful for diagnosing this hyperinflammation syndrome. Low-dose dexamethasone therapy currently is the best therapeutic approach. 5. The fifth goal is to identify and address the hypercoagulability phase seen in many hospitalized COVID-19 patients. Patients who would benefit from anticoagulation therapy can be identified by a marked increase in d-dimer and prothrombin time with a decrease in fibrinogen. To correct this disseminated intravascular coagulation-like phase, anticoagulation therapy with low molecular weight heparin is preferred. Anticoagulation therapy with unfractionated heparin is preferred in COVID-19 patients with acute kidney injuries. 6. The last goal is prophylaxis for persons who are not yet infected. Potential supplements include vitamin D and zinc. Although the data for such supplements is not extremely strong, it can be argued that almost 50% of the population worldwide has a vitamin D deficiency. Correcting this deficiency would be beneficial regardless of any impact of COVID-19. Similarly, zinc is an important supplement that is important in one's diet regardless of any effect on SARS-CoV-2. As emerging therapies are found to be more effective against the SARS-CoV-2 pathogenic mechanisms identified, they can be substituted for those therapies presented in this review.

Impact of disease-modifying drugs on the severity of COVID-19 infection in multiple sclerosis patients

Recent evidence suggested that neurological manifestations occur in patients with a severe form of coronavirus disease (COVID-19). On the basis of this issue, neurologists are very concerned about patients with neurological disorders, especially multiple sclerosis (MS), as consumers of immunosuppressive or immune-modulating drugs. Therefore, the administration of proper disease-modifying therapies (DMTs) in MS patients is critical during the pandemic status. On the one hand, both the autoimmune diseases and immunosuppressive drugs increase the risk of infection due to impairment in the immune system, and on the other hand, postponing of MS treatment has serious consequences on the central nervous system. In the present study, we discussed recent literature about the effect of DMTs administration on the severity of COVID-19 in the MS patients. Overall, it seems that DMTs do not provoke the COVID-19 infection in the MS patients by declining immune responses and cytokine storm. However, as a precaution, the supervision of a neurologist is highly recommended.

Update on cerebrovascular manifestations of COVID-19

The novel member of coronaviruses family, severe acute respiratory coronavirus-2 (SARS-CoV-2), with high structural homology to SARS-CoV and Middle East respiratory syndrome-related coronavirus (MERS) has spread rapidly with about 20 million cases infection and over 700,000 deaths. SARS-CoV-2 has been emerged as a worldwide disaster due to non-specific few respiratory and gastrointestinal manifestations at the onset of disease as well as long incubation period. Surprisingly, not only respiratory failure but also the underlying coagulation disorder and neurovascular involvement worsen the clinical outcome of infected patients. In this review article, we describe the probable mechanisms of SARS-CoV-2 infection and stroke occurrence. We will also discuss the cerebrovascular events following SARS-CoV-2 infection, the recommended therapies, and future prospects to better manage these patients in coronavirus disease 2019 (COVID-19) outbreak.

Abnormal antibodies to self-carbohydrates in SARS-CoV-2 infected patients

SARS-CoV-2 is a deadly virus that is causing the global pandemic coronavirus disease 2019 (COVID-19). Our immune system plays a critical role in preventing, clearing, and treating the virus, but aberrant immune responses can contribute to deleterious symptoms and mortality. Many aspects of immune responses to SARS-CoV-2 are being investigated, but little is known about immune responses to carbohydrates. Since the surface of the virus is heavily glycosylated, pre-existing antibodies to glycans could potentially recognize the virus and influence disease progression. Furthermore, antibody responses to carbohydrates could be induced, affecting disease severity and clinical outcome. In this study, we used a carbohydrate antigen microarray with over 800 individual components to profile serum anti-glycan antibodies in COVID-19 patients and healthy control subjects. In COVID-19 patients, we observed abnormally high IgG and IgM antibodies to numerous self-glycans, including gangliosides, N -linked glycans, LacNAc-containing glycans, blood group H, and sialyl Lewis X. Some of these anti-glycan antibodies are known to play roles in autoimmune diseases and neurological disorders, which may help explain some of the unusual and prolonged symptoms observed in COVID-19 patients. The detection of antibodies to self-glycans has important implications for using convalescent serum to treat patients, developing safe and effective SARS-CoV-2 vaccines, and understanding the risks of infection. In addition, this study provides new insight into the immune responses to SARS-CoV-2 and illustrates the importance of including host and viral carbohydrate antigens when studying immune responses to viruses.