Post-COVID-19 Sydenham Chorea: A Case Report

Background: Sydenham chorea, or rheumatic chorea, is a movement disorder that is more prevalent among young people, with a mean age at symptom onset between 8 and 9 years. The condition is more common in females. Sydenham chorea is associated with rheumatic fever and is considered the most common cause of acute chorea in children. We believe that the present case is worth reporting since the occurrence of Sydenham chorea as a post-COVID-19 sequela has not been described in Brazil. Case Presentation: We report here the case of a 14-year-old girl with symptoms of acute chorea that emerged 15 days after treatment resolution of COVID-19 (SARS-CoV-2 or severe acute respiratory syndrome coronavirus 2). Brain computed tomography (CT) and magnetic resonance imaging scans showed no changes, and the laboratory tests revealed no signs of an active infectious process. In contrast, neurological positron-emission tomography/CT showed mild glycolytic hypometabolism in the bilateral mesial frontal region. Administration of an oral anticonvulsant resulted in a marked improvement in her symptoms. Conclusion(s): Despite major efforts of the scientific community for discovering treatments, preventive methods, mechanisms of action, and possible sequelae of SARS-CoV-2, there is still a long way to go to better understand this devastating pathological agent that has affected the global population.Copyright © 2023 Camargo and Morcillo.

Astrocytes in the pathophysiology of neuroinfection.

Key homeostasis providing cells in the central nervous system (CNS) are astrocytes, which belong to the class of cells known as atroglia, a highly heterogeneous type of neuroglia and a prominent element of the brain defence. Diseases evolve due to altered homeostatic state, associated with pathology-induced astroglia remodelling represented by reactive astrocytes, astroglial atrophy and astrodegeneration. These features are hallmarks of most infectious insults, mediated by bacteria, protozoa and viruses; they are also prominent in the systemic infection. The COVID-19 pandemic revived the focus into neurotropic viruses such as SARS-CoV2 (Coronaviridae) but also the Flaviviridae viruses including tick-borne encephalitis (TBEV) and Zika virus (ZIKV) causing the epidemic in South America prior to COVID-19. Astrocytes provide a key response to neurotropic infections in the CNS. Astrocytes form a parenchymal part of the blood-brain barrier, the site of virus entry into the CNS. Astrocytes exhibit aerobic glycolysis, a form of metabolism characteristic of highly morphologically plastic cells, like cancer cells, hence a suitable milieu for multiplication of infectious agent, including viral particles. However, why the protection afforded by astrocytes fails in some circumstances is an open question to be studied in the future.

Meningeal macrophages protect against viral neuroinfection.

The surface of the central nervous system (CNS) is protected by the meninges, which contain a dense network of meningeal macrophages (MMs). Here, we examined the role of tissue-resident MM in viral infection. MHC-II- MM were abundant neonatally, whereas MHC-II+ MM appeared over time. These barrier macrophages differentially responded to in vivo peripheral challenges such as LPS, SARS-CoV-2, and lymphocytic choriomeningitis virus (LCMV). Peripheral LCMV infection, which was asymptomatic, led to a transient infection and activation of the meninges. Mice lacking macrophages but conserving brain microglia, or mice bearing macrophage-specific deletion of Stat1 or Ifnar, exhibited extensive viral spread into the CNS. Transcranial pharmacological depletion strategies targeting MM locally resulted in several areas of the meninges becoming infected and fatal meningitis. Low numbers of MHC-II+ MM, which is seen upon LPS challenge or in neonates, corelated with higher viral load upon infection. Thus, MMs protect against viral infection and may present targets for therapeutic manipulation.

A Remarkable Case of Acute Motor-Sensory Axonal Polyneuropathy (AMSAN) Variant of Guillain Barré Syndrome, in a Diabetic Patient Infected With COVID-19: A Case Report and Review of the Literature.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease- 2019 (COVID-19), has been a global epidemic in our healthcare system. SARS-CoV-2 primarily affects the respiratory system, but neurological involvement has also been reported, including Guillain-Barré syndrome (GBS) development. Case Presentation: A 58-year-old male with known co-morbid hypertension and type 2 diabetes mellitus presented to the emergency room with complaints of worsening shortness of breath, dry cough, and fever for the past 10 days. On day 20 of hospitalization, he developed neurological symptoms after being tested positive for COVID-19. A neuroelectrophysiology study was conducted to evaluate neurological symptoms and suggested that the patient suffers from acute motor-sensory axonal polyneuropathy (AMSAN). CSF analysis showed elevated protein levels that confirmed the diagnosis of GBS. He was subsequently treated with oral prednisolone and IVIG, which improved neurological symptoms. Conclusion: Ever since the emergence of COVID-19, GBS has surfaced as to its potentially dangerous outcome. Healthcare professionals should be mindful of GBS and should rule it out in anyone having sensory symptoms or weakness during or after a COVID-19 infection. Its early detection and treatment can result in improved clinical outcomes.

Experimental Models of SARS-COV-2 Infection in the Central Nervous System.

Coronavirus disease 2019 (COVID-19) has raised serious concerns worldwide due to its great impact on human health and forced scientists racing to find effective therapies to control the infection and a vaccine for the virus. To this end, intense research efforts have focused on understanding the viral biology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for COVID-19. The ever-expanding list of cases, reporting clinical neurological complications in COVID-19 patients, strongly suggests the possibility of the virus invading the nervous system. The pathophysiological processes responsible for the neurological impact of COVID-19 are not fully understood. Some neurodegenerative disorders sometimes take more than a decade to manifest, so the long-term pathophysiological outcomes of SARS-CoV-2 neurotropism should be regarded as a challenge for researchers in this field. There is no documentation on the long-term impact of SARS-CoV-2 on the human central nervous system (CNS). Most of the data relating to neurological damage during SARS-CoV-2 infection have yet to be established experimentally. The purpose of this review is to describe the knowledge gained, from experimental models, to date, on the mechanisms of neuronal invasion and the effects produced by infection. The hope is that, once the processes are understood, therapies can be implemented to limit the damage produced. Long-term monitoring and the use of appropriate and effective therapies could reduce the severity of symptoms and improve quality of life of the most severely affected patients, with a special focus on those have required hospital care and assisted respiration.

Microgliosis and neuronal proteinopathy in brain persist beyond viral clearance in SARS-CoV-2 hamster model.

BACKGROUND: Neurological symptoms such as cognitive decline and depression contribute substantially to post-COVID-19 syndrome, defined as lasting symptoms several weeks after initial SARS-CoV-2 infection. The pathogenesis is still elusive, which hampers appropriate treatment. Neuroinflammatory responses and neurodegenerative processes may occur in absence of overt neuroinvasion. METHODS: Here we determined whether intranasal SARS-CoV-2 infection in male and female syrian golden hamsters results in persistent brain pathology. Brains 3 (symptomatic) or 14 days (viral clearance) post infection versus mock (n = 10 each) were immunohistochemically analyzed for viral protein, neuroinflammatory response and accumulation of tau, hyperphosphorylated tau and alpha-synuclein protein. FINDINGS: Viral protein in the nasal cavity led to pronounced microglia activation in the olfactory bulb beyond viral clearance. Cortical but not hippocampal neurons accumulated hyperphosphorylated tau and alpha-synuclein, in the absence of overt inflammation and neurodegeneration. Importantly, not all brain regions were affected, which is in line with selective vulnerability. INTERPRETATION: Thus, despite the absence of virus in brain, neurons develop signatures of proteinopathies that may contribute to progressive neuronal dysfunction. Further in depth analysis of this important mechanism is required. FUNDING: Federal Ministry of Health (BMG; ZMV I 1-2520COR501), Federal Ministry of Education and Research (BMBF 01KI1723G), Ministry of Science and Culture of Lower Saxony in Germany (14 - 76103-184 CORONA-15/20), German Research Foundation (DFG; 398066876/GRK 2485/1), Luxemburgish National Research Fund (FNR, Project Reference: 15686728, EU SC1-PHE-CORONAVIRUS-2020 MANCO, no > 101003651).

COVID-19-Associated Encephalopathy-Case Series and Clinical Considerations.

Neurological manifestations of the SARS-CoV-2 infection are present in up to 80% of the affected patients. While the majority of them is benign, in certain patients, viral replication in the central nervous system results in a severe disruption in cognitive function as well as basic life functions. In this case series, the authors present a detailed description of the three SARS-CoV-2 infection cases, which were all complicated by severe encephalopathy. Consecutive neurological status changes were described for each patient with detailed imaging and clinical sequelae. In the discussion, the authors highlight similarities in the course of the disease in presented patients, as well as common features in test results. An effective causal treatment could not be introduced in any of the patients, nor could the progression of the central nervous system (CNS) damage be stopped. The authors hope that the experiences they gathered will help to accelerate the diagnostic and therapeutic process in other patients with COVID-19-associated encephalopathy and result in introducing an effective treatment.

Systematic review of cases of acute myelitis in individuals with COVID-19.

BACKGROUND AND PURPOSE: An incremental number of cases of acute transverse myelitis (ATM) in individuals with ongoing or recent coronavirus disease 2019 (COVID-19) have been reported. METHODS: A systematic review was performed of cases of ATM described in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by screening both articles published and in preprint. RESULTS: Twenty cases were identified. There was a slight male predominance (60.0%) and the median age was 56 years. Neurological symptoms first manifested after a mean of 10.3 days from the first onset of classical, mostly respiratory symptoms of COVID-19. Overall, COVID-19 severity was relatively mild. Polymerase chain reaction of cerebrospinal fluid for SARS-CoV-2 was negative in all 14 cases examined. Cerebrospinal fluid findings reflected an inflammatory process in most instances (77.8%). Aquaporin-4 and myelin oligodendrocyte protein antibodies in serum (tested in 10 and nine cases, respectively) were negative. On magnetic resonance imaging, the spinal cord lesions spanned a mean of 9.8 vertebral segments, necrotic-hemorrhagic transformation was present in three cases and two individuals had additional acute motor axonal neuropathy. More than half of the patients received a second immunotherapy regimen. Over a limited follow-up period of several weeks, 90% of individuals recovered either partially or near fully. CONCLUSION: Although causality cannot readily be inferred, it is possible that cases of ATM occur para- or post-infectiously in COVID-19. All identified reports are anecdotal and case descriptions are heterogeneous. Whether the condition and the observed radiological characteristics are specific to SARS-CoV-2 infection needs to be clarified.

Neural Infection by Oropouche Virus in Adult Human Brain Slices Induces an Inflammatory and Toxic Response.

Oropouche virus (OROV) is an emerging arbovirus in South and Central Americas with high spreading potential. OROV infection has been associated with neurological complications and OROV genomic RNA has been detected in cerebrospinal fluid from patients, suggesting its neuroinvasive potential. Motivated by these findings, neurotropism and neuropathogenesis of OROV have been investigated in vivo in murine models, which do not fully recapitulate the complexity of the human brain. Here we have used slice cultures from adult human brains to investigate whether OROV is capable of infecting mature human neural cells in a context of preserved neural connections and brain cytoarchitecture. Our results demonstrate that human neural cells can be infected ex vivo by OROV and support the production of infectious viral particles. Moreover, OROV infection led to the release of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) and diminished cell viability 48 h post-infection, indicating that OROV triggers an inflammatory response and tissue damage. Although OROV-positive neurons were observed, microglia were the most abundant central nervous system (CNS) cell type infected by OROV, suggesting that they play an important role in the response to CNS infection by OROV in the adult human brain. Importantly, we found no OROV-infected astrocytes. To the best of our knowledge, this is the first direct demonstration of OROV infection in human brain cells. Combined with previous data from murine models and case reports of OROV genome detection in cerebrospinal fluid from patients, our data shed light on OROV neuropathogenesis and help raising awareness about acute and possibly chronic consequences of OROV infection in the human brain.

Cerebral venous thrombosis in a patient with Down syndrome and coronavirus disease 2019: a case report.

BACKGROUND: The new coronavirus disease 2019 pandemic has spread throughout most of the world. Cerebral venous thrombosis is a rare thromboembolic disease that can present as an extrapulmonary complication in coronavirus disease 2019 infection. CASE PRESENTATION: We report the case of a Hispanic woman with Down syndrome who has coronavirus disease 2019 and presents as a complication extensive cerebral venous thrombosis. CONCLUSIONS: Cerebral venous thrombosis is a rare thromboembolic disease that can present as an extrapulmonary complication in coronavirus disease 2019 infection. In the absence of clinical and epidemiological data, it is important to carry out further investigation of the risk factors and pathophysiological causes related to the development of cerebrovascular thrombotic events in patients with Down syndrome with coronavirus disease 2019 infection.

Neurodegenerative proteinopathies associated with neuroinfections.

Infectious agents, including viruses and bacteria, are proposed to be involved in the pathogenesis of Alzheimer's disease (AD). According to this hypothesis, these agents have capacity to evade the host immune system leading to chronic infection, inflammation, and subsequent deposition of Aß and phosphorylated-tau in the brain. Co-existing proteinopathies and age-related pathologies are common in AD and the brains of elderly individuals, but whether these are also related to neuroinfections remain to be established. This study determined the prevalence and distribution of neurodegenerative proteinopathies in patients with infection-induced acute or chronic inflammation associated with herpes simplex virus (HSV) encephalitis (n = 13) and neurosyphilis (n = 23). The mean age at death in HSV patients was 53 ± 12 years (range 24-65 years) and survival was 9 days-6 years following initial infection. The mean age at death and survival in neurosyphilis patients was 60 ± 15 years (range 36-86 years) and 1-5 years, respectively. Neuronal tau-immunoreactivity and neurites were observed in 8 HSV patients and 19 neurosyphilis patients, and in approximately half of these, this was found in regions associated with inflammation and expanding beyond regions expected from the Braak stage of neurofibrillary degeneration. Five neurosyphilis patients had cortical ageing-related tau astrogliopathy. Aß-plaques were found in 4 HSV patients and 11 neurosyphilis patients. Lewy bodies were observed in one HSV patient and two neurosyphilis patients. TDP-43 pathology was absent. These observations provide insights into deposition of neurodegenerative proteins in neuroinfections, which might have implications for COVID-19 patients with chronic and/or post-infectious neurological symptoms and encephalitis.

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.

Neurotropic Viruses, Astrocytes, and COVID-19.

At the end of 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was discovered in China, causing a new coronavirus disease, termed COVID-19 by the WHO on February 11, 2020. At the time of this paper (January 31, 2021), more than 100 million cases have been recorded, which have claimed over 2 million lives worldwide. The most important clinical presentation of COVID-19 is severe pneumonia; however, many patients present various neurological symptoms, ranging from loss of olfaction, nausea, dizziness, and headache to encephalopathy and stroke, with a high prevalence of inflammatory central nervous system (CNS) syndromes. SARS-CoV-2 may also target the respiratory center in the brainstem and cause silent hypoxemia. However, the neurotropic mechanism(s) by which SARS-CoV-2 affects the CNS remain(s) unclear. In this paper, we first address the involvement of astrocytes in COVID-19 and then elucidate the present knowledge on SARS-CoV-2 as a neurotropic virus as well as several other neurotropic flaviviruses (with a particular emphasis on the West Nile virus, tick-borne encephalitis virus, and Zika virus) to highlight the neurotropic mechanisms that target astroglial cells in the CNS. These key homeostasis-providing cells in the CNS exhibit many functions that act as a favorable milieu for virus replication and possibly a favorable environment for SARS-CoV-2 as well. The role of astrocytes in COVID-19 pathology, related to aging and neurodegenerative disorders, and environmental factors, is discussed. Understanding these mechanisms is key to better understanding the pathophysiology of COVID-19 and for developing new strategies to mitigate the neurotropic manifestations of COVID-19.

Neuropathophysiology of coronavirus disease 2019: neuroinflammation and blood brain barrier disruption are critical pathophysiological processes that contribute to the clinical symptoms of SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) is caused by the novel SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) first discovered in Wuhan, Hubei province, China in December 2019. SARS-CoV-2 has infected several millions of people, resulting in a huge socioeconomic cost and over 2.5 million deaths worldwide. Though the pathogenesis of COVID-19 is not fully understood, data have consistently shown that SARS-CoV-2 mainly affects the respiratory and gastrointestinal tracts. Nevertheless, accumulating evidence has implicated the central nervous system in the pathogenesis of SARS-CoV-2 infection. Unfortunately, however, the mechanisms of SARS-CoV-2 induced impairment of the central nervous system are not completely known. Here, we review the literature on possible neuropathogenic mechanisms of SARS-CoV-2 induced cerebral damage. The results suggest that downregulation of angiotensin converting enzyme 2 (ACE2) with increased activity of the transmembrane protease serine 2 (TMPRSS2) and cathepsin L in SARS-CoV-2 neuroinvasion may result in upregulation of proinflammatory mediators and reactive species that trigger neuroinflammatory response and blood brain barrier disruption. Furthermore, dysregulation of hormone and neurotransmitter signalling may constitute a fundamental mechanism involved in the neuropathogenic sequelae of SARS-CoV-2 infection. The viral RNA or antigenic peptides also activate or interact with molecular signalling pathways mediated by pattern recognition receptors (e.g., toll-like receptors), nuclear factor kappa B, Janus kinase/signal transducer and activator of transcription, complement cascades, and cell suicide molecules. Potential molecular targets and therapeutics of SARS-CoV-2 induced neurologic damage are also discussed.

A Contemporary Review of Neurological Sequelae of COVID-19.

Coronavirus 2019 (COVID-19) is currently the center of what has become a public health crisis. While the virus is well-known for its trademark effects on respiratory function, neurological damage has been reported to affect a considerable proportion of severe cases. To characterize the neuro-invasive potential of this disease, a contemporary review of COVID-19 and its neurological sequelae was conducted using the limited, but growing, literature that is available. These neurological squeal are based on the manifestations that the virus has on normal central and peripheral nervous system function. The authors present the virology of the SARS-CoV-2 agent by analyzing its classification as an enveloped, positive-stranded RNA virus. A comprehensive timeline is then presented, indicating the progression of the disease as a public health threat. Furthermore, underlying chronic neurological conditions potentially lead to more adverse cases of COVID-19. SARS-CoV-2 may reach ACE2 receptors on neuronal tissue through mode of the general circulation. The CNS may also be susceptible to an immune response where a "cytokine storm" can manifest into neural injury. Histological evidence is provided, while symptoms such as headache and vertigo are highlighted as CNS manifestations of COVID-19. Treatment of these symptoms is addressed with paracetamol being recommended as a possible, but not conclusive, treatment to some CNS symptoms. The authors then discuss the peripheral nervous system sequelae and COVID's impact on causing chemosensory dysfunction starting with viral attack on olfactory sensory neurons and cells types within the lining of the nose. Histological evidence is also provided while symptoms such as anosmia and ageusia are characterized as PNS manifestations. Possible treatment options for these symptoms are then addressed as a major limitation, as anecdotal, and not conclusive evidence can be made. Finally, preventive measures of the neurological sequelae are addressed using a multidirectional approach. Postmortem examinations of the brains of COVID-19 patients are suggested as being a possible key to formulating new understandings of its neuropathology. Lastly, the authors suggest a more comprehensive neurological follow-up of recovered patients, in order to better characterize the neurological sequelae of this illness.