SARS-CoV-2-related Myelin Oligodendrocyte Glycoprotein Antibody-associated Disease: A Case Report and Literature Review

A comparative study on anti-MOG and anti-AQP4 associated optic neuritis following mild COVID-19: insights from a Chinese single-center experience

Background

Research on the relationship between mild COVID-19 and the subsequent development of isolated optic neuritis (ON) with antibodies specific to myelin oligodendrocyte glycoprotein (MOG-ON) and aquaporin 4 (AQP4-ON) is limited, particularly case-control studies that directly compare these conditions within the same affected population.

Methods

A retrospective analysis of initial MOG-ON and AQP4-ON cases during the COVID-19 peak and subsequent months. Patients were classified as possible COVID-19 related ON (PCRON) or non-COVID-19 related ON (NCRON). The study compared epidemiology, comorbidities, and clinical features between these groups.

Results

Patients with MOG-ON tended to develop ON symptoms closer in time to a mild COVID-19 infection compared to those with AQP4-ON (6.87 ± 6.25 weeks vs. 11.06 ± 5.84 weeks; p = 0.038), a significantly higher proportion of patients with MON-ON developing symptoms within 6 weeks after COVID-19 compared to those with AQP4-ON (15/23 [65.2%] vs. 5/17 [29.4%]; p = 0.025). Comparing MOG-ON and AQP4-ON patients, MOG-ON patients were more likely to have a recent infection before ON onset (73.1% vs. 30%; p = 0.007) and had better peak and post-treatment visual acuity (p = 0.01; p < 0.001). In contrast, AQP4-ON patients frequently showed comorbid connective tissue diseases (30.0% vs. 0%, p = 0.004) and antinuclear antibody abnormalities (40.0% vs. 7.7%, p = 0.012). Among MOG-ON patients, PCRON had increased rates of atherosclerotic vascular diseases (AVDs) (53.3% vs. 9.1%, p = 0.036), phospholipid antibody abnormalities (60.0% vs. 18.2%, p = 0.04), and bilateral visual impairment (66.7% vs. 9.1%, p = 0.005). Multivariate analysis pinpointed AVDs (OR = 15.21, p = 0.043) and bilateral involvement (OR = 25.15, p = 0.015) as independent factors related to COVID-19 associated MOG-ON, with both being good discriminators for PCRON (AUC = 0.879). No differences were found between the PCRON and NCRON groups in AQP4-ON patients.

Conclusion

Mild COVID-19 is more likely associated with MOG-ON than AQP4-ON. MOG-ON that develops within 6 weeks following a COVID-19 infection may be associated with the COVID-19 infection. AVDs may have a synergistic effect on MOG-ON in patients with COVID-19, which warrants further investigation. COVID-19 related MOG-ON often affects both eyes, and acute visual function damage can be severe, but generally has a good prognosis.

Is there an immunological cross-reactivity of antibodies to the myelin oligodendrocyte glycoprotein and coronaviruses?

Recent reports indicated that myelin oligodendrocyte glycoprotein antibody-associated disease might be a rare complication after severe acute respiratory syndrome coronavirus 2 infection or vaccination. It is unclear whether this is an unspecific sequel of infection or vaccination or caused by possible immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 proteins and myelin oligodendrocyte glycoprotein. The aim of this study was therefore to elucidate whether there is an immunological cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike or nucleocapsid proteins and myelin oligodendrocyte glycoprotein and to explore the relation of antibody responses against myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 and other coronaviruses. We analysed serum samples from patients with severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 12) or without myelin oligodendrocyte glycoprotein-antibodies (n = 10); severe acute respiratory syndrome coronavirus 2 infection without neurological symptoms (n = 32); vaccinated patients with no history of severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 10) or without myelin oligodendrocyte glycoprotein-antibodies (n = 9); and severe acute respiratory syndrome coronavirus 2 negative/naïve unvaccinated patients with neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 47) or without myelin oligodendrocyte glycoprotein-antibodies (n = 20). All samples were analysed for serum antibody responses to myelin oligodendrocyte glycoprotein, severe acute respiratory syndrome coronavirus 2, and other common coronaviruses (CoV-229E, CoV-HKU1, CoV-NL63 and CoV-OC43). Based on sample amount and antibody titres, 21 samples were selected for analysis of antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 spike and nucleocapsid proteins using affinity purification and pre-absorption. Whereas we found no association of immunoglobulin G and A myelin oligodendrocyte glycoprotein antibodies with coronavirus antibodies, infections with severe acute respiratory syndrome coronavirus 2 correlated with an increased immunoglobulin M myelin oligodendrocyte glycoprotein antibody response. Purified antibodies showed no cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike protein and myelin oligodendrocyte glycoprotein. However, one sample of a patient with myelin oligodendrocyte glycoprotein antibody-associated disease following severe acute respiratory syndrome coronavirus 2 infection showed a clear immunoglobulin G antibody cross-reactivity to severe acute respiratory syndrome coronavirus 2 nucleocapsid protein and myelin oligodendrocyte glycoprotein. This patient was also seropositive for other coronaviruses and showed immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 and CoV-229E nucleocapsid proteins. Overall, our results indicate that an immunoglobulin G antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 proteins is rare. The presence of increased myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies after severe acute respiratory syndrome coronavirus 2 infection may either be a consequence of a previous infection with other coronaviruses or arise as an unspecific sequel after viral infection. Furthermore, our data indicate that myelin oligodendrocyte glycoprotein-immunoglobulin A and particularly myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies are a rather unspecific sequel of viral infections. Finally, our findings do not support a causative role of coronavirus infections for the presence of myelin oligodendrocyte glycoprotein-immunoglobulin G antibodies.

A review of neuro-ophthalmic sequelae following COVID-19 infection and vaccination

Background

It has become increasingly clear that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect most organs in the human body, including the neurologic and ophthalmic systems. Vaccination campaigns have been developed at rapid pace around the world to protect the population from the fast-mutating virus. This review seeks to summarise current knowledge of the neuro-ophthalmic manifestations of both COVID-19 infection and vaccination.

Evidence acquisition

Electronic searches for published literature were conducted using EMBASE and MEDLINE on the 30th of July 2023. The search strategy comprised of controlled vocabulary and free-text synonyms for the following terms in various combinations: "coronavirus, COVID-19, SARS-CoV-2, 2019-nCoV, vaccination, vaccine, immunisation and neuro-ophthalmology". No time range limits were set for the literature search. Published English abstracts for articles written in a different language were screened if available.

Results

A total of 54 case reports and case series were selected for use in the final report. 34 articles documenting neuro-ophthalmic manifestations following COVID-19 infection and 20 articles with neuro-ophthalmic complications following COVID-19 vaccination were included, comprising of 79 patients in total. The most commonly occurring condition was optic neuritis, with 25 cases following COVID-19 infection and 27 cases following vaccination against COVID-19.

Conclusions

The various COVID-19 vaccines that are currently available are part of the global effort to protect the most vulnerable of the human population. The incidence of neuro-ophthalmic consequences following infection with COVID-19 is hundred-folds higher and associated with more harrowing systemic effects than vaccination against the virus.

Delimiting MOGAD as a disease entity using translational imaging

The first formal consensus diagnostic criteria for myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) were recently proposed. Yet, the distinction of MOGAD-defining characteristics from characteristics of its important differential diagnoses such as multiple sclerosis (MS) and aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorder (NMOSD) is still obstructed. In preclinical research, MOG antibody-based animal models were used for decades to derive knowledge about MS. In clinical research, people with MOGAD have been combined into cohorts with other diagnoses. Thus, it remains unclear to which extent the generated knowledge is specifically applicable to MOGAD. Translational research can contribute to identifying MOGAD characteristic features by establishing imaging methods and outcome parameters on proven pathophysiological grounds. This article reviews suitable animal models for translational MOGAD research and the current state and prospect of translational imaging in MOGAD.

Systematic review exploring the clinical features of optic neuritis after SARS-CoV infection and vaccination

BACKGROUND

This study aims to characterise the symptoms and clinical features of optic neuritis (ON) following SARS-CoV-2 infection and vaccination.

METHOD

A literature search was conducted in four databases (PubMed, Medline, Embase and Google Scholar) to identify relevant case reports and case series. The records were screened and articles adhering to the inclusion criteria were critically appraised.

RESULTS

Sixty-eight studies were found to be eligible for inclusion, including 34 reporting ON following SARS-CoV-2 infection and an equal number reporting cases postvaccination. In total 93 patients and 125 eyes were included. The infection cohort included 42 patients and 56 eyes, 51.2% were female and 33.3% experienced bilateral ON. The mean visual acuity was 1.64 log of minimum angle of resolution (LogMAR), while pain was present in 77.8%. Oligoclonal bands were present in 3 patients, myelin oligodendrocyte glycoprotein (MOG) antibodies in 18 patients and AQP-4 antibodies in 4 patients. The vaccination cohort included 51 patients and 69 eyes. 60.8% were female and 35.3% had a bilateral ON. The mean visual acuity was 0.93 LogMAR. Oligoclonal bands were present in 46.7%, MOG antibodies in nine patients and AQP-4 antibodies in three patients.

CONCLUSION

Patients with ON post-SARS-CoV infection were more likely to experience severe visual impairment than in cases following vaccination. Further research is required to outline the clinical features of ON after COVID-19 infection and vaccination, and establish causality.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease and COVID-19: A Systematic Review

Background

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an uncommon neurological disease affecting the central nervous system (CNS). Numerous neurological disorders, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), acute transverse myelitis (ATM), and MOGAD, have been reported following the COVID-19 infection during the current COVID-19 pandemic. On the other hand, it has been suggested that patients with MOGAD may be at greater risk for infection (particularly in the current pandemic).

Objective

In this systematic review, we gathered separately 1) MOGAD cases following COVID-19 infection as well as 2) clinical course of patients with MOGAD infected with COVID-19 based on case reports/series.

Methods

329 articles were collected from 4 databases. These articles were conducted from inception to March 1st, 2022.

Results

Following the screening, exclusion criteria were followed and eventually, 22 studies were included. In 18 studies, a mean ± SD time interval of 18.6 ± 14.9 days was observed between infection with COVID-19 and the onset of MOGAD symptoms. Symptoms were partially or completely recovered in a mean of 67 days of follow-up. Among 4 studies on MOGAD patients, the hospitalization rate was 25%, and 15% of patients were hospitalized in the intensive care unit (ICU).

Conclusion

Our systematic review demonstrated that following COVID-19 infection, there is a rare possibility of contracting MOGAD. Moreover, there is no clear consensus on the susceptibility of MOGAD patients to severe COVID-19. However, obtaining deterministic results requires studies with a larger sample size.

SARS-CoV-2 Parainfectious Optic Neuropathy: 3 Case Reports and a Review of the Literature

BACKGROUND

Parainfectious optic neuritis is an inflammatory reaction that occurs shortly after an infection without direct invasion by a pathogen. The clinical profile depends on the infectious organism. Cases of SARS-CoV-2 parainfectious optic neuritis have been reported in the literature, but there are no reviews that have applied strict inclusion criteria to more definitively establish the clinical profile associated with SARS-CoV-2.

METHODS

We present 3 new cases of SARS-CoV-2 parainfectious optic neuritis. We also review the literature for definite cases by selecting only those with unambiguous clinical features and MRI findings of optic neuritis, positive SARS-CoV-2 polymerase chain reaction or serology, and the absence of myelin oligodendrocyte-glycoprotein or aquaporin-4 antibodies or other diseases associated with optic neuritis.

RESULTS

We report 2 cases of monophasic, unilateral SARS-CoV-2 parainfectious optic neuritis with optic disc edema and nadir visual acuities of finger counting. We report 1 case of mild SARS-CoV-2 parainfectious optic neuritis that featured cotton wool spots, peripapillary wrinkles and hemorrhages, and recurrence after an initial steroid taper. We identified 6 cases of unambiguous SARS-CoV-2 parainfectious optic neuritis from the literature. Combining our case series with the case reports in the literature, the average age was 42.8 years, 3/9 had bilateral disease, 6/8 had optic disc edema, 8/9 had nadir visual acuity of finger counting or worse, and all recovered visual acuity to 20/40 or better after therapy with steroids.

CONCLUSIONS

SARS-CoV-2 parainfectious optic neuritis has a clinical profile that is atypical for idiopathic optic neuritis but fairly typical of parainfectious forms of optic neuritis with a severely reduced nadir visual acuity, high likelihood of bilaterality, high incidence of optic disc edema, and prompt and significant response to corticosteroids. Further study with long-term follow-up and epidemiologic investigation will be needed to further characterize this clinical entity.

Prevalence of serum MOG antibody and AQP4 antibody in optic neuritis after SARS-CoV-2 infection

Purpose

To evaluate the prevalence of serum myelin oligodendrocyte glycoprotein antibody (MOG-Ab) and aquaporin-4 antibody (AQP4-Ab) in optic neuritis (ON) patients after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by cell-based indirect immunofluorescence assay (CBA).

Methods

In this prospective case series study, 35 patients clinically diagnosed as ON and laboratory-confirmed SARS-CoV-2 infection from 8 December 2022 to 8 February 2023 were included. All patients' clinical and laboratory data were collected and analyzed.

Results

The mean age of the 35 patients (46 eyes) was 38.2 years (ranging from 6 to 69 years), and 17 cases were female patients. Thirty-three and two cases showed positive SARS-CoV-2 RNA test results before or shortly after ON onset, respectively. ON occurred unilaterally in 24 cases and bilaterally in 11 cases. Ophthalmic examination revealed swollen optic disc in 37 eyes, normal optic disc in 6 eyes, and temporally or wholly paled optic disc in 3 eyes. CBA revealed seropositive MOG-Ab in 10 cases and AQP4-Ab in 2 cases, respectively, of which 2 AQP4-Ab-seropositive cases and 1 MOG-Ab-seropositive case had a past medical history of ON. Most ON patients showed a rapid and dramatic response to pulse steroid therapy. The median of BCVA at the onset and at the last follow-up was 20/500 (ranging from light perception to 20/20) and 20/67 (ranging from counting fingers to 20/20), respectively.

Conclusion

Serum MOG-Ab and AQP4-Ab were detected in 28.6% (10/35) and 5.7% (2/35) ON cases after SARS-CoV-2 infection. SARS-CoV-2 infection may trigger an onset or a relapse of ON, as well as the production of MOG-Ab.

The Role of MRI in Differentiating Demyelinating and Inflammatory (not Infectious) Myelopathies

Demyelinating and inflammatory myelopathies represent a group of diseases with characteristic patterns in neuroimaging and several differential diagnoses. The main imaging patterns of demyelinating myelopathies (multiple sclerosis, neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis, and myelin oligodendrocyte glycoprotein antibody-related disorder) and inflammatory myelopathies (systemic lupus erythematosus-myelitis, sarcoidosis-myelitis, Sjögren-myelitis, and Behçet's-myelitis) will be discussed in this article, highlighting key points to the differential diagnosis.

MOG-IgG positive optic neuritis after SARS-CoV-2 infection

BACKGROUND

Many neurologic complications have been described after severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) including atypical cases of optic neuritis (ON), positive to myelin oligodendrocyte glycoprotein (MOG) IgG.

OBJECTIVE

To report a case of MOG-IgG-associated ON and discuss why SARS-CoV-2 infection could be a potential trigger.

METHODS

Retrospective single case report.

RESULTS

We report a case of ON with positive MOG-IgG developed 15 days after presentation of SARS-CoV-2 infection.

CONCLUSION

This report suggests that SARS-CoV-2 infection may have triggered autoantibodies production against MOG leading to ON.

Hippocampal subfield abnormalities and biomarkers of pathologic brain changes: from SARS-CoV-2 acute infection to post-COVID syndrome

BACKGROUND

Cognitive deficits are among the main disabling symptoms in COVID-19 patients and post-COVID syndrome (PCS). Within brain regions, the hippocampus, a key region for cognition, has shown vulnerability to SARS-CoV-2 infection. Therefore, in vivo detailed evaluation of hippocampal changes in PCS patients, validated on post-mortem samples of COVID-19 patients at the acute phase, would shed light into the relationship between COVID-19 and cognition.

METHODS

Hippocampal subfields volume, microstructure, and perfusion were evaluated in 84 PCS patients and compared to 33 controls. Associations with blood biomarkers, including glial fibrillary acidic protein (GFAP), myelin oligodendrocyte glycoprotein (MOG), eotaxin-1 (CCL11) and neurofilament light chain (NfL) were evaluated. Besides, biomarker immunodetection in seven hippocampal necropsies of patients at the acute phase were contrasted against eight controls.

FINDINGS

In vivo analyses revealed that hippocampal grey matter atrophy is accompanied by altered microstructural integrity, hypoperfusion, and functional connectivity changes in PCS patients. Hippocampal structural and functional alterations were related to cognitive dysfunction, particularly attention and memory. GFAP, MOG, CCL11 and NfL biomarkers revealed alterations in PCS, and showed associations with hippocampal volume changes, in selective hippocampal subfields. Moreover, post mortem histology showed the presence of increased GFAP and CCL11 and reduced MOG concentrations in the hippocampus in post-mortem samples at the acute phase.

INTERPRETATION

The current results evidenced that PCS patients with cognitive sequalae present brain alterations related to cognitive dysfunction, accompanied by a cascade of pathological alterations in blood biomarkers, indicating axonal damage, astrocyte alterations, neuronal injury, and myelin changes that are already present from the acute phase.

FUNDING

Nominative Grant FIBHCSC 2020 COVID-19. Department of Health, Community of Madrid. Instituto de Salud Carlos III through the project INT20/00079, co-funded by European Regional Development Fund "A way to make Europe" (JAMG). Instituto de Salud Carlos III (ISCIII) through Sara Borrell postdoctoral fellowship Grant No. CD22/00043) and co-funded by the European Union (MDC). Instituto de Salud Carlos III through a predoctoral contract (FI20/000145) (co-funded by European Regional Development Fund "A way to make Europe") (MVS). Fundación para el Conocimiento Madri+d through the project G63-HEALTHSTARPLUS-HSP4 (JAMG, SOM).

Neuro-Ophthalmic Visual Impairment in the Setting of COVID-19

We set out to describe in detail the afferent neuro-ophthalmological complications that have been reported in association with coronavirus disease 2019 (COVID-19) infection. We describe and elaborate on mechanisms of disease, including para-infectious inflammation, hypercoagulability, endothelial damage, and direct neurotropic viral invasion. Despite global vaccination programs, new variants of COVID-19 continue to pose an international threat, and patients with rare neuro-ophthalmic complications are likely to continue to present for care.Afferent complications from COVID-19 include homonymous visual field loss, with or without higher cortical visual syndromes, resulting from stroke, intracerebral hemorrhage, or posterior reversible leukoencephalopathy. Optic neuritis has frequently been reported, sometimes along with acute disseminated encephalomyelopathy, often in association with either myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) or less commonly aquaporin-4 seropositivity or in newly diagnosed multiple sclerosis. Ischemic optic neuropathy has rarely been reported. Papilledema, resulting either from venous sinus thrombosis or idiopathic intracranial hypertension in the setting of COVID-19, has also been described.Observed afferent neuro-ophthalmic associations need to be confirmed though larger comparative studies. Meanwhile, the range of possible complications should be recognized by neurologists and ophthalmologists alike, to facilitate faster diagnosis and treatment of both COVID-19 and its neuro-ophthalmic manifestations.

Relapsing Encephalomyelitis After COVID-19 Infection and Vaccination: From the National MS Society Case Conference Proceedings

Prior case studies suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its vaccines may unmask CNS neuroinflammatory conditions. We present a case of relapsing steroid-responsive encephalomyelitis after SARS-CoV-2 infection and subsequent COVID-19 vaccination. We also characterize the frequency of CNS neuroinflammatory events reported in the literature after both SARS-CoV-2 infection and COVID-19 vaccination.

Central Nervous System Neuroimmunologic Complications of COVID-19

Autoimmune disorders of the central nervous system following COVID-19 infection include multiple sclerosis (MS), neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, autoimmune encephalitis, acute disseminated encephalomyelitis, and other less common neuroimmunologic disorders. In general, these disorders are rare and likely represent postinfectious phenomena rather than direct consequences of the SARS-CoV-2 virus itself. The impact of COVID-19 infection on patients with preexisting neuroinflammatory disorders depends on both the disorder and disease-modifying therapy use. Patients with MS do not have an increased risk for severe COVID-19, though patients on anti-CD20 therapies may have worse clinical outcomes and attenuated humoral response to vaccination. Data are limited for other neuroinflammatory disorders, but known risk factors such as older age and medical comorbidities likely play a role. Prophylaxis and treatment for COVID-19 should be considered in patients with preexisting neuroinflammatory disorders at high risk for developing severe COVID-19.

Myelin oligodendrocyte glycoprotein antibody-associated encephalitis after severe acute respiratory syndrome coronavirus 2 infection: a case report and retrospective case reviews

Several cases of myelin oligodendrocyte glycoprotein (MOG) antibody-associated encephalitis have been reported after coronavirus disease 2019 (COVID-19). In this case, the patient presented with focal status epilepticus with impaired awareness, auditory hallucinations, and incoherent speech after COVID-19. Brain magnetic resonance imaging revealed no specific findings. Cerebrospinal fluid results showed pleocytosis and MOG antibody testing confirmed anti-MOG antibody with live cell-based fluorescence-activated cell sorting assay. The patient was diagnosed with MOG antibody-associated autoimmune encephalitis and treated with intravenous immunoglobulin, rituximab, and tocilizumab. This case occurred presumably due to auto-antibody production following COVID-19.

Relapsing Anti-MOG Antibody-associated Disease following COVID-19 Vaccination: A Rare Case Report and Review of the Literature

Anti-myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune demyelinating disorder that mainly occurs post-infection or post-vaccination. MOGAD after inoculation with coronavirus disease 2019 (COVID-19) vaccines is rare, and we herein report a rare case of a patient with MOGAD after vaccination using the Pfizer-BioNTech COVID-19 vaccine (BNT162b2, Pfizer Japan, Tokyo). Our report highlights the fact that MOGAD following inoculation with COVID-19 vaccine may show clinical relapse during reduction of the oral steroid dose, and continuous treatments with immunological agents is needed to prevent disease recurrence.

Fluoxetine plus lithium for treatment of mental health impairment in Long Covid

Purposes

(1) To summarize the mental conditions that may accompany persistent symptoms following acute infection by SARS-CoV-2, often termed Long Covid; (2) to formulate treatment based upon the brain cells that are dominantly affected.

Methods

(1) Review the reports relating to the mental symptoms occurring in Long Covid. (2) Review the drugs that address the brain cells affected in Long Covid, and suggest pharmacotherapy for those patients whose response to psychotherapy is suboptimal.

Results

Long Covid affects ~ 10% of patients infected by SARS-CoV-2, and mental symptoms affect ~ 20% of persons with Long Covid. The brain cell-types that have been demonstrated as dominantly affected in Long Covid are astrocytes, oligodendrocytes, neurons, endothelial cells/pericytes, and microglia. Lithium and fluoxetine each address all of those four cell-types. Low dosage of each is likely to be well-tolerated and to cause neither clinically important adverse events (AE) nor serious adverse events (SAE).

Conclusion

For those patients whose response to psychotherapy is suboptimal, lithium and fluoxetine should be administered in combination for both depth of benefit and reduction of dosages.

Transverse myelitis following COVID-19: Insights from a multi-center study and systematic literature review

INTRODUCTION

We aimed to provide insights into transverse myelitis (TM) following COVID-19 by analyzing cases treated at tertiary care neurology centers and a systemic review of the literature.

METHODS

The retrospective observational multi-center study was conducted at the four university neurology departments in Croatia, Slovenia, Serbia, and Austria. We searched for acute myelitis cases that occurred during or after COVID-19. A systemic review of the literature on COVID-19 and transverse myelitis was performed.

RESULTS

We identified 76 persons with TM associated with COVID-19, 13 from the multi-center study and 63 from the literature review. Most of the participants (55.6%) had an intermediate latency, 25.4% had short and 19% long latency from COVID-19 symptoms to TM. The clinical presentation consisted of the typical TM signs. More than half of the participants had inflammatory changes in the CSF, with rare patients having intrathecal OCB synthesis and positive serology for anti-MOG or anti-AQP4 antibodies. Persons with autonomic symptoms and CSF pleocytosis were significantly more common to have an intermediate latency of 8 to 21 days from COVID-19 to TM (p = 0.005 and p = 0.003; respectively). According to logistic regression analysis, only participants with lesions evident on spinal cord MRI compared to normal spinal cord MRI had reduced risks for poor recovery. >80% of participants were treated with a combination of corticosteroids and intravenous immunoglobulins or plasma exchange with 73% having incomplete recovery.

CONCLUSION

Our study further characterizes clinical, laboratory, and MRI features, as well as treatment of TM associated with COVID-19.

COVID-19 and the risk of CNS demyelinating diseases: A systematic review

Background

Viral infections are a proposed possible cause of inflammatory central nervous system (CNS) demyelinating diseases, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). During the past 2 years, CNS demyelinating events associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, but causality is unclear.

Objective

To investigate the relationship between CNS demyelinating disease development and exacerbation with antecedent and/or concurrent SARS-CoV-2 infection.

Methods

A systematic literature review of all publications describing either a new diagnosis or relapse of CNS demyelinating diseases (MS, NMOSD, MOGAD) in association with SARS-CoV-2 infection was performed utilizing PRISMA guidelines. Descriptive statistics were used for data analysis, using a case analysis approach.

Results

Sixty-seven articles met the inclusion criteria for the study. Most of the reported cases of NMOSD (n = 13, 72.2% of reported cases) and MOGAD (n = 27, 96.5% of reported cases) were of new disease onset, presenting with typical clinical and radiographic features of these conditions, respectively. In contrast, reported MS cases varied amongst newly diagnosed cases (n = 10, 10.5% of reported cases), relapses (n = 63, 66.4%) and pseudo-relapses (n = 22, 23.2%). The median duration between COVID-19 infection and demyelinating event onset was 11.5 days (range 0–90 days) in NMOSD, 6 days (range−7 to +45 days) in MOGAD, and 13.5 days (range−21 to +180 days) in MS. Most cases received high-dose corticosteroids with a good clinical outcome.

Conclusion

Based upon available literature, the rate of CNS demyelinating events occurring in the setting of preceding or concurrent SARS-CoV-2 infection is relatively low considering the prevalence of SARS-CoV-2 infection. The clinical outcomes of new onset or relapsing MS, NMOSD, or MOGAD associated with antecedent or concurrent infection were mostly favorable. Larger prospective epidemiological studies are needed to better delineate the impact of COVID-19 on CNS demyelinating diseases.

CRISPR/CasRx-Mediated RNA Knockdown Reveals That ACE2 Is Involved in the Regulation of Oligodendroglial Cell Morphological Differentiation

Angiotensin-converting enzyme 2 (ACE2) plays a role in catalyzing angiotensin II conversion to angiotensin (1–7), which often counteracts the renin-angiotensin system. ACE2 is expressed not only in the cells of peripheral tissues such as the heart and kidney, but also in those of the central nervous system (CNS). Additionally, ACE2 acts as the receptor required for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), whose binding leads to endocytotic recycling and possible degradation of the ACE2 proteins themselves. One of the target cells for SARS-CoV-2 in the CNS is oligodendrocytes (oligodendroglial cells), which wrap neuronal axons with their differentiated plasma membranes called myelin membranes. Here, for the first time, we describe the role of ACE2 in FBD-102b cells, which are used as the differentiation models of oligodendroglial cells. Unexpectedly, RNA knockdown of ACE2 with CasRx-mediated gRNA or the cognate siRNA promoted oligodendroglial cell morphological differentiation with increased expression or phosphorylation levels of differentiation and/or myelin marker proteins, suggesting the negative role of ACE2 in morphological differentiation. Notably, ACE2′s intracellular region preferentially interacted with the active GTP-bound form of Ras. Thus, knockdown of ACE2 relatively increased GTP-bound Ras in an affinity-precipitation assay. Indeed, inhibition of Ras resulted in decreasing both morphological differentiation and expression or phosphorylation levels of marker proteins, confirming the positive role of Ras in differentiation. These results indicate the role of ACE2 itself as a negative regulator of oligodendroglial cell morphological differentiation, newly adding ACE2 to the list of regulators of oligodendroglial morphogenesis as well as of Ras-binding proteins. These findings might help us to understand why SARS-CoV-2 causes pathological effects in the CNS.