Influenza-associated MOG antibody-positive longitudinally extensive transverse myelitis: a case report

Extremely Longitudinally Extensive Transverse Myelitis in a Patient With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

Longitudinally extensive myelitis with 15 or more vertebrae in length is extremely rare, with limited evidence regarding clinical features and therapeutic response. We report a case of a 29-year-old male patient with extremely longitudinally extensive myelitis ultimately diagnosed as myelin oligodendrocyte glycoprotein-associated disease (MOGAD). The patient presented with an acute onset of meningismus, limb weakness, sensory disturbance below the C5 level, ataxia, and urinary retention. T2-weighted imaging on MRI showed an extremely longitudinally extensive spinal cord lesion ranging from C2 to the medullary conus, together with a left pontine lesion. Positive anti-myelin oligodendrocyte glycoprotein antibodies were serologically detected, which led to the diagnosis of MOGAD. Intravenous methylprednisolone followed by 1 mg/kg oral prednisolone with taper resulted in complete symptomatic and radiological resolution. The striking complete resolution despite the symptomatic and radiological severity observed in this case has been described in a few previously reported MOGAD cases. Extremely longitudinally extensive myelitis with excellent therapeutic response may be a characteristic presentation of MOGAD.

A Case Report of NMO Transverse Myelitis

BACKGROUND

Transverse myelitis is considered one of the cardinal features of neuromyelitis optica spectrum disorder (NMOSD), an immune-mediated inflammatory condition of the CNS characterized by severe, immune-mediated demyelination and axonal damage predominantly targeting optic nerves and spinal cord. We describe a case in which a diagnosis of NMOSD was established, associated with West Nile Virus (WNV) infection.

CASE PRESENTATION

A healthy 18-year-old female presented with intractable hiccups and rapidly progressing paraparesis. MRI demonstrated T2 edema extending from the medulla to the conus, consistent with longitudinally extensive transverse myelitis. Serum and CSF Aquaporin-4 IgG (AQP4) were both positive with high titers. In conjunction with antiviral therapy, immunomodulatory treatment was initiated using pulse methylprednisolone, plasmapheresis and Rituximab. A month and a half after admission, the patient was fully ambulatory with no residual symptoms. On her rheumatology follow-up visit, West Nile Virus-specific IgM in CSF was found to be positive from the patient's initial presentation.

CONCLUSION

We propose that West Nile Virus may have been the autoimmune trigger to the patient's development of NMOSD, highlighting the importance of evaluating viral triggers in autoimmune diseases.

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.

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.

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.

Onset of various CNS inflammatory demyelination diseases following COVID-19 vaccinations

BACKGROUND

Since the start of COVID-19 vaccination worldwide, there have been several reports of inflammatory demyelinating diseases of the central nervous system (CNS-IDDs) following vaccination.

METHODS

We prospectively collected cases of new-onset CNS-IDDs with a temporal relationship between disease onset and COVID-19 vaccination and investigated their proportion among newly registered cases of CNS-IDD over the past year.

RESULTS

Among 117 cases, 10 (8.5%) had their first disease manifestation within one month following COVID-19 vaccination: 2 multiple sclerosis, 2 neuromyelitis optica spectrum disorder, 3 MOG antibody-associated disease, and 3 unclassified CNS-IDDs.

CONCLUSION

This observation suggests that COVID-19 vaccination may trigger the onset of various CNS-IDDs in susceptible individuals.

Myelin Oligodendrocyte Glycoprotein-Associated Disorders

PURPOSE OF REVIEW

Anti-myelin oligodendrocyte glycoprotein (MOG) autoantibodies have become a recognized cause of a pathophysiologically distinct group of central nervous system (CNS) autoimmune diseases. MOG-associated disorders can easily be confused with other CNS diseases such as multiple sclerosis or neuromyelitis optica, but they have a distinct clinical phenotype and prognosis.

RECENT FINDINGS

Most patients with MOG-associated disorders exhibit optic neuritis, myelitis, or acute disseminated encephalomyelitis (ADEM) alone, sequentially, or in combination; the disease may be either monophasic or relapsing. Recent case reports have continued to expand the clinical spectrum of disease, and increasingly larger cohort studies have helped clarify its pathophysiology and natural history.

SUMMARY

Anti-MOG-associated disorders comprise a substantial subset of patients previously thought to have other seronegative CNS diseases. Accurate diagnosis is important because the relapse patterns and prognosis for MOG-associated disorders are unique. Immunotherapy appears to successfully mitigate the disease, although not all agents are equally effective. The emerging large-scale data describing the clinical spectrum and natural history of MOG-associated disorders will be foundational for future therapeutic trials.

Post-COVID-19 Longitudinally Extensive Transverse Myelitis with Myelin Oligodendrocyte Glycoprotein Antibodies

Background

Myelin oligodendrocyte glycoprotein (MOG) antibody disease most commonly presents with optic neuritis, though myelitis is also possible. It is rare in the post-infectious and particularly post-COVID-19 setting. Case Presentation. We present the case of a 57-year-old man who tested positive for COVID-19 and experienced respiratory symptoms that completely resolved within one week. About 3 weeks after testing positive, he began experiencing acute onset anuria, followed by lower extremity paresthesia and paraparesis, which progressed to bilateral lower extremity paraplegia, complete loss of sensation of pain, temperature, vibration, and proprioception, and a T4 sensory level. He was initially diagnosed with and treated for acute inflammatory demyelinating polyradiculoneuropathy (AIDP), after which he made minimal clinical improvement. The diagnosis was shifted to longitudinally extensive transverse myelitis, and his CSF tested positive for MOG antibodies. He is being treated with a steroid regimen and extensive outpatient physical therapy.

Conclusion

The neurologic manifestations of COVID-19 are still being uncovered. Neurologic symptoms should be included in patient education on symptom monitoring, even after recovery of respiratory illness, so that COVID-19-related CNS pathology can be urgently treated.

A Rare Case of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Transverse Myelitis in a 40-Year-Old Patient With COVID-19

The coronavirus disease 2019 (COVID-19) includes an extensive spectrum of clinical manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Previous studies have shown that SARS-CoV-2 often exhibits central nervous system (CNS) manifestations, including encephalitis, meningitis, and spinal cord pathologies. To date, few cases of COVID-19-associated transverse myelitis (TM) have been described. A 40-year-old unvaccinated man with no significant medical history presented to the emergency department complaining of fever, worsening burning sensation in his lower extremities, unsteady gait, and difficulty initiating urination for five days. Twelve days before presentation, the patient had tested positive for SARS-CoV-2 infection. Physical examination revealed hyperesthesia, starting around the nipple line (T4) and extending distally, involving the lower extremities, accompanied by symmetric weakness in the lower extremities. Magnetic resonance imaging of the thoracic spine with and without contrast revealed mild intramedullary signal abnormality at T3-T4 and T6-T8, confirming the suspicion of TM. Further laboratory testing revealed a C-reactive protein level of 67 mg/L, lactate dehydrogenase level of 181 mg/L, serum B12 level of 781 pg/mL, methylmalonic acid level of 165 nmol/L, folate of >24.5 ng/mL, and thyroid-stimulating hormone level of 0.481 μIU/L. Lumbar puncture was performed, and cerebrospinal fluid analysis revealed a cell count of 14 cells/µL, with 69% lymphocytes, glucose level of 81 mg/dL, protein level of 32 mg/dL, and negative cultures. Human immunodeficiency virus, antinuclear antibody screening, anti-DNA, rapid plasma reagin, Lyme serology, anti-SSA, and anti-SSB antibodies were unremarkable. Serum aquaporin-4 immunoglobulin G was negative, and myelin oligodendrocyte glycoprotein (MOG) antibodies were positive. The patient was treated with intravenous methylprednisolone and oral gabapentin and was discharged after five days when his urinary retention improved. Most previously reported cases of COVID-19-related TM were negative for autoimmune workup. Although the exact pathophysiology of COVID-19-related TM remains unclear, one hypothesis suggests that it is a consequence of the direct viral invasion. However, our patient had MOG antibodies, suggesting the possible involvement of a different mechanism. In MOG-associated TM, it has been suggested that MOG antibodies gain access to the CNS through disruption of the blood-brain barrier. This unique presentation demonstrates that further studies are needed to understand the effects of SARS-CoV-2 infection on the immune and nervous systems. It also highlights that young and otherwise healthy patients are at risk of severe COVID-19-related complications, including CNS disorders.

Extensive Longitudinal Transverse Myelitis after Influenza A Virus Infection in a Patient with Systemic Lupus Erythematosus

Transverse myelitis (TM) is a rare complication seen in 1–2% of patients with systemic lupus erythematosus (SLE). Viral infections may cause TM in these patients by causing a dysregulation of their immune system. We report a 30-year-old woman with SLE who had influenza A and a few days later developed urinary retention, bilateral lower extremity paralysis, upper extremity weakness, and optic nerve and macular edema. Magnetic resonance imaging showed C4-T12 hyperintense lesions consistent with TM. She was treated with intravenous methylprednisolone 1 g daily for 3 days and then 6 cycles of monthly intravenous cyclophosphamide. This treatment was followed by oral prednisone. She had a remarkable clinical response. Visual acuity improved to her baseline, and muscle strength almost fully recovered. Clinicians should be aware that viral infections, including influenza, may induce TM. This case highlights the importance of early recognition and prompt treatment with immunosuppressive drugs in such cases.

MOG-antibody-associated longitudinal extensive myelitis after ChAdOx1 nCoV-19 vaccination

This case report describes a 59-year-old man with myelin oligodendrocyte glycoprotein (MOG)-positive longitudinal extensive transverse myelitis (LETM) after being vaccinated with the COVID-19 vaccine ChAdOx1 nCoV-19. He presented with urinary retention, gait disturbance, hypoesthesia and brisk reflexes in his lower extremities without paresis. Due to the ineffectiveness of high-dose intravenous methylprednisolone, therapeutic plasma exchange was performed, gradually improving the patient's condition. Vaccination as a trigger for an excessive immunological response seems plausible, though unspecific for the ChAdOx1 nCoV-19 vaccine.

Seasonal variation in attacks of neuromyelitis optica spectrum disorders and multiple sclerosis: Evaluation of 794 attacks from a nationwide registry in Argentina

BACKGROUND

Identification of triggers that potentially instigate attacks in neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) has remained challenging. We aimed to analyze the seasonality of NMOSD and MS attacks in an Argentinean cohort seeking differences between the two disorders.

METHODS

A retrospective study was conducted in a cohort of NMOSD and MS patients followed in specialized centers from Argentina and enrolled in RelevarEM, a nationwide, longitudinal, observational, non-mandatory registry of MS/NMOSD patients. Patients with complete relapse data (date, month and year) at onset and during follow-up were included. Attack counts were analyzed by month using a Poisson regression model with the median monthly attack count used as reference.

RESULTS

A total of 551 patients (431 MS and 120 NMOSD), experiencing 236 NMOSD-related attacks and 558 MS-related attacks were enrolled. The mean age at disease onset in NMOSD was 39.5 ± 5.8 vs. 31.2 ± 9.6 years in MS (p < 0.01). Mean follow-up time was 6.1 ± 3.0 vs. 7.4 ± 2.4 years (p < 0.01), respectively. Most of the included patients were female in both groups (79% vs. 60%, p < 0.01). We found a peak of number of attacks in June (NMOSD: 28 attacks (11.8%) vs MS: 33 attacks (5.9%), incidence rate ratio 1.82, 95%CI 1.15-2.12, p = 0.03), but no differences were found across the months in both disorders when evaluated separately. Strikingly, we observed a significant difference in the incidence rate ratio of attacks during the winter season when comparing NMOSD vs. MS (NMOSD: 75 attacks (31.7%) vs MS: 96 attacks (17.2%), incidence rate ratio 1.82, 95%CI 1.21-2.01, p = 0.02) after applying Poisson regression model. Similar results were observed when comparing the seropositive NMOSD (n = 75) subgroup vs. MS.

CONCLUSIONS

Lack of seasonal variation in MS and NMOSD attacks was observed when evaluated separately. Future epidemiological studies about the effect of different environmental factors on MS and NMOSD attacks should be evaluated prospectively in Latin America population.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease and Varicella Zoster Virus Infection - Frequency of an Association

To determine whether there is a correlation between myelin oligodendrocyte glycoprotein (MOG) antibody-associated diseases and varicella zoster virus (VZV) infection. We provide a case report and performed a study to determine the frequency of MOG antibodies (MOG-IgG) in neurological VZV infections. Patients admitted to the Medical University of Innsbruck from 2008-2020 with a diagnosis of a neurological manifestation of VZV infection (n=59) were included in this study; patients with neuroborreliosis (n=34) served as control group. MOG-IgG was detected using live cell-based assays. In addition, we performed a literature review focusing on MOG and aquaporin-4 (AQP4) antibodies and their association with VZV infection. Our case presented with VZV-associated longitudinally extensive transverse myelitis and had MOG-IgG at a titer of 1:1280. In the study, we did not detect MOG-IgG in any other patient neither in the VZV group (including 15 with VZV encephalitis/myelitis) nor in the neuroborreliosis group. In the review of the literature, 3 cases with MOG-IgG and additional 9 cases with AQP4 IgG associated disorders in association with a VZV infection were identified. MOG-IgG are rarely detected in patients with VZV infections associated with neurological diseases.

Transient Myelin Oligodendrocyte Glycoprotein Antibody-positive Acute Disseminated Encephalomyelitis Following Influenza A Infection: A Rare Case

Acute disseminated encephalomyelitis (ADEM) is an uncommon disease generally with a preceding history of infectious illness. Here, we report a rare case of ADEM following influenza A infection with transient detection of anti-myelin oligodendrocyte glycoprotein (MOG) antibody in a young male patient who presented with extensive demyelination of brain and spinal cord, likely the result of dysregulated immune response from previous influenza A infection. The patient presented to the emergency with urinary retention and progressive ascending weakness of lower limbs. Magnetic resonance imaging (MRI) of the brain and spinal cord showed multiple ill-defined hyperintensities, suggestive of demyelination. The clinical presentation, MRI findings, cerebrospinal fluid examination, negative anti-aquaporin-4 antibody and metabolic and other viral infectious screening supported the diagnosis of ADEM. The patient had transiently positive anti-MOG antibodies (for 3 months) and was treated with intravenous immunoglobulin followed by oral prednisolone for 3 months. There was a significant recovery in the upper limb weakness and brainstem function. This case highlights the association of anti-MOG antibody with ADEM following viral infections and the need for prolonged follow-up to differentiate between transient antibodies from relapsing MOG antibody disease.

In Vivo Models to Study the Pathogenesis of Extra-Respiratory Complications of Influenza A Virus Infection

Animal models are an inimitable method to study the systemic pathogenesis of virus-induced disease. Extra-respiratory complications of influenza A virus infections are not extensively studied even though they are often associated with severe disease and mortality. Here we review and recommend mammalian animal models that can be used to study extra-respiratory complications of the central nervous system and cardiovascular system as well as involvement of the eye, placenta, fetus, lacteal gland, liver, pancreas, intestinal tract, and lymphoid tissues during influenza A virus infections.

Seasonal variation of onset in patients with anti-aquaporin-4 antibodies and anti-myelin oligodendrocyte glycoprotein antibody

This study aimed to determine the seasonal impact on the clinical onset of inflammatory neurological diseases of the central nervous system by analyzing the onset month with information on clinical manifestations in Japanese patients. As a result, patients with anti-aquaporin-4 antibodies (AQP4-IgG)-positive neuromyelitis optica spectrum disorders (NMOSD) showed spring-summer predominance of the clinical onset. Conversely, patients with anti-myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disease showed autumn-winter predominance of the clinical onset. Both seasonal variations were irrespective of the clinical manifestation. Environmental factors with seasonal variation influence the development of neurological conditions related to AQP4-IgG and MOG-IgG.

Anti-NMDA receptor encephalitis concomitant with myelin oligodendrocyte glycoprotein antibody diseases: A retrospective observational study

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARe) can coexist with myelin oligodendrocyte glycoprotein antibody (MOG-ab) disease.To characterize MOG-ab disease during NMDARe, we analyzed all the patients with MOG-ab disease and NMDARe from our hospital from December 2018 to December 2019 and data from a systematical review of previously published reports. Details of the patients identified were summarized and literature was reviewed.Four of thirty (14.2%) patients with anti-NMDARe had overlapping MOG-ab disease in our department. Analyze together with previously reported cases. Thirty-two NMDARe patients had overlapping MOG-ab disease. The onset age ranged from 3 to 48 years. Twenty-four patients (74%) developed abnormal behavior or cognitive dysfunction during the episodes of anti-NMDARe. None of these patients had tumors. 84% (27/32) patients received high doses of steroids as first-line immunotherapy and 28% (9/32) received mycophenolate mofetil (MMF) to prevent relapse. Twenty-six of twenty-seven (96%) had a good outcome.Steroids are the most common first-line immunotherapies in NMDARe overlapping MOG-ab disease. Most of the NMDARe patients overlapping MOG-ab disease have a good prognosis.

Postinfectious Acute Disseminated Encephalomyelitis Associated With Antimyelin Oligodendrocyte Glycoprotein Antibody

Myelin oligodendrocyte glycoprotein is a major target of the humoral immune response in children affected by inflammatory demyelinating diseases of the central nervous system. Although myelin oligodendrocyte glycoprotein causes autoimmune encephalitis in different animal models, the relevance of this mechanism in human autoimmune diseases of the central nervous system is unclear. We herein report a child with acute disseminated encephalomyelitis possibly triggered by central nervous system infection of primary herpes simplex virus in the presence of antimyelin oligodendrocyte glycoprotein antibody. A healthy 5-year-old Japanese boy suffered from acute disseminated encephalomyelitis. He was positive for antimyelin oligodendrocyte glycoprotein antibody in both the serum and the cerebrospinal fluid, and herpes simplex virus-1 DNA on polymerase chain reaction of the cerebrospinal fluid. We speculated that the central nervous system infection of primary herpes simplex virus disrupted the blood–brain barrier, and antimyelin oligodendrocyte glycoprotein antibody already present in serum was transferred to the cerebrospinal fluid, resulting in the onset of acute disseminated encephalomyelitis. This might be the mechanism underlying postinfectious acute disseminated encephalomyelitis associated with myelin oligodendrocyte glycoprotein antibody.

Unfavorable Structural and Functional Outcomes in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis

BACKGROUND

Recurrent optic neuritis (rON) associated with myelin oligodendrocyte glycoprotein (MOG)-specific antibodies has been initially reported to show a better clinical outcome than aquaporin-4 (AQP4)-seropositive ON in neuromyelitis optica spectrum disorder (NMOSD). Here, we characterize clinical and neuroimaging findings in severe cases of MOG antibody-positive and AQP4 antibody-negative bilateral rON.

METHODS

Three male adults with rON (ages 18, 44, and 63 years) were evaluated with optical coherence tomography (OCT), MRI, cerebrospinal fluid (CSF), and serological studies.

RESULTS

All patients experienced >7 relapses of ON with severe reduction of visual acuity and partial response to steroid treatment. Optic nerves were affected bilaterally, although unilateral relapses were more frequent than simultaneous bilateral recurrences. Patients were MOG-seropositive but repeatedly tested negative for AQP4 antibodies. OCT showed severe thinning of the peripapillary retinal nerve fiber layer. On MRI, contrast-enhancing lesions extended over more than half the length of the optic nerve. CSF analyses during ON episodes were normal. Severe visual deficits accumulated over time in 2 of 3 patients, despite immunosuppressive therapy.

CONCLUSIONS

MOG-seropositive and AQP4-seronegative rON may be associated with an aggressive disease course and poor functional and structural outcomes. In contrast to previous reports, the severity and pattern of retinal and optic nerve damage closely resembled phenotypes commonly observed in AQP4-seropositive rON without fulfilling current diagnostic criteria for NMOSD.

Increased risk of non-multiple sclerosis demyelinating syndromes in patients with preexisting septicaemia: a nationwide retrospective cohort study

Background

Growing evidence shows links between septicaemia and non-multiple sclerosis demyelinating syndromes (NMSDS); nevertheless, epidemiological data are still very limited. This study aimed to explore the relationship between septicaemia and NMSDS in a general population.

Methods

The study included 482 781 individuals diagnosed with septicaemia and 1 892 825 age/sex-matched non-septicaemia patients for the comparison. Data were drawn from a population-based nationwide National Health Insurance Research Database Taiwan, from 1 January 2002 to 31 December 2011. The two cohorts of patients with and without septicaemia were followed up for the occurrence of NMSDS. The Cox-proportional hazard regression model was performed to estimate adjusted HR after multivariate adjustment.

Results

Individuals with septicaemia had a 4.17-fold (95% CI 3.21 to 5.4, p < 0.001) higher risk to develop NMSDS compared with those without septicaemia. Patients aged <65 years had a greater NMSDS risk (<45 years: HR = 6.41, 95% CI 3.65 to 11.3, p < 0.001; 45–64 years: HR = 6.66, 95% CI 3.98 to 11.2, p < 0.001). Furthermore, females with septicaemia and individuals with higher severity of septicaemia were associated with increased risks of developing NMSDS.

Conclusions

Our results indicated that patients with septicaemia were likely to develop NMSDS. A possible contributing role of septicaemia in increasing the hazard of NMSDS is proposed, based on the outcome that individuals with higher severity of septicaemia carried elevated threat of encountering NMSDS.

Neuroinflammation During RNA Viral Infections

Neurotropic RNA viruses continue to emerge and are increasingly linked to diseases of the central nervous system (CNS) despite viral clearance. Indeed, the overall mortality of viral encephalitis in immunocompetent individuals is low, suggesting efficient mechanisms of virologic control within the CNS. Both immune and neural cells participate in this process, which requires extensive innate immune signaling between resident and infiltrating cells, including microglia and monocytes, that regulate the effector functions of antiviral T and B cells as they gain access to CNS compartments. While these interactions promote viral clearance via mainly neuroprotective mechanisms, they may also promote neuropathology and, in some cases, induce persistent alterations in CNS physiology and function that manifest as neurologic and psychiatric diseases. This review discusses mechanisms of RNA virus clearance and neurotoxicity during viral encephalitis with a focus on the cytokines essential for immune and neural cell inflammatory responses and interactions. Understanding neuroimmune communications in the setting of viral infections is essential for the development of treatments that augment neuroprotective processes while limiting ongoing immunopathological processes that cause ongoing CNS disease.

Longitudinally extensive transverse myelitis in a patient infected with West Nile virus

Until now, longitudinally extensive transverse myelitis (LETM) was reported in association with various viral infections. We describe the case in which a diagnosis of LETM was established as a clinical manifestation of West Nile virus (WNV) infection. We report a 39-year old man with WNV infection and LETM. In neurological examination, there was a left periscapular hypotrophy, moderate weakness of left arm, decreased left brachioradialis reflex, tandem instability and gait ataxia. Cervical spine MRI showed enhancing intramedullary lesion extending from C3-C7 level. According to the neurological, EMG and MRI findings, a diagnosis of LETM, with affection of anterior horn cells of the cervical spinal cord, induced by WNV infection was established. The patient was treated with antibiotics, acyclovir and high dose-steroids, methylprednisolone (MP) 1 g/daily in intravenous infusion, for 5 consecutive days, followed by tapering doses of prednisone during the next four months. Six weeks after onset of symptoms, previously described lesion on cervical spine MRI resolved, and the patient gradually clinically improved.

Anti-Myelin Oligodendrocyte Glycoprotein Antibody Associated With Gray Matter Predominant Transverse Myelitis Mimicking Acute Flaccid Myelitis: A Presentation of Two Cases

BACKGROUND

Anti-myelin oligodendrocyte glycoprotein (MOG) antibody associated disorders frequently manifest as optic neuritis, transverse myelitis, and acute disseminated encephalomyelitis. While their clinical phenotypes overlap with relapsing inflammatory Central nervous system (CNS) conditions such as multiple sclerosis and neuromyelitis optica spectrum disorder, MOG-related syndromes frequently occur in a younger age group. In children, longitudinally extensive transverse myelitis (LETM) is less specific for anti-aquaporin-4 associated neuromyelitis optica spectrum disorder, and has also been reported in pediatric multiple sclerosis, idiopathic transverse myelitis, and acute flaccid myelitis.

METHODS

We summarize two patients with positive MOG antibodies and myelitis.

RESULTS

We identified two individuals with anti-MOG associated LETM that demonstrate primarily gray matter involvement. Clinically these patients exhibited hyperreflexia and had rapid improvement with immunotherapies.

CONCLUSIONS

Anti-MOG diseases can cause LETM with gray matter predominance mimicking acute flaccid myelitis, but clinically these patients can have retained reflexes and respond favorably to immunotherapies.

The hidden burden of influenza: A review of the extra-pulmonary complications of influenza infection

Severe influenza infection represents a leading cause of global morbidity and mortality. Although influenza is primarily considered a viral infection that results in pathology limited to the respiratory system, clinical reports suggest that influenza infection is frequently associated with a number of clinical syndromes that involve organ systems outside the respiratory tract. A comprehensive MEDLINE literature review of articles pertaining to extra‐pulmonary complications of influenza infection, using organ‐specific search terms, yielded 218 articles including case reports, epidemiologic investigations, and autopsy studies that were reviewed to determine the clinical involvement of other organs. The most frequently described clinical entities were viral myocarditis and viral encephalitis. Recognition of these extra‐pulmonary complications is critical to determining the true burden of influenza infection and initiating organ‐specific supportive care.

MOG-IgG-Associated Optic Neuritis, Encephalitis, and Myelitis: Lessons Learned From Neuromyelitis Optica Spectrum Disorder

Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have been found in some cases diagnosed as seronegative neuromyelitis optica spectrum disorder (NMOSD). MOG-IgG allowed the identification of a subgroup with a clinical course distinct from that of NMOSD patients who are seropositive for aquaporin-4-IgG antibodies. MOG-IgG is associated with a wider clinical phenotype, not limited to NMOSD, with the majority of cases presenting with optic neuritis (ON), encephalitis with brain demyelinating lesions, and/or myelitis. Therefore, we propose the term MOG-IgG-associated Optic Neuritis, Encephalitis, and Myelitis (MONEM). Depending on the clinical characteristics, these patients may currently be diagnosed with NMOSD, acute disseminated encephalomyelitis, pediatric multiple sclerosis, transverse myelitis, or ON. With specific cell-based assays, MOG-IgG is emerging as a potential biomarker of inflammatory disorders of the central nervous system. We review the growing body of evidence on MONEM, focusing on its clinical aspects.

Defining distinct features of anti-MOG antibody associated central nervous system demyelination

Extensive research over the last decades basically failed to identify a common cause of noninfectious inflammatory central nervous system (CNS) demyelinating disease. To a great extent, this may reflect that the group of inflammatory CNS demyelinating disorders likely contains multiple pathogenetically distinct disease entities. Indeed, the greatest success so far in deciphering the pathogenesis of a CNS demyelinating disorder resulted from the discovery of anti-aquaporin (AQP)-4 antibodies (ab), which allowed progressive delineation of neuromyelitis optica (NMO), formerly considered a variant of the most common CNS demyelinating disorder, multiple sclerosis (MS), as a distinct disease. Nowadays, AQP-4⁺ NMO is considered an autoimmune astrocytopathy, in which CNS demyelination occurs only as a consequence of a primary destruction of astrocytes. Delineating these patients concomitantly revealed that not all patients presenting with clinically NMO-suggestive disease phenotype express AQP-4 ab, which created the pathogenetically undefined category of NMO spectrum disorders (NMOSD). Recent investigations discovered that a subgroup of these AQP-4^– NMOSD patients produce an ab response against myelin oligodendrocyte glycoprotein (MOG), a molecule expressed on the outer lamella of the myelin sheath. Using pathophysiologically meaningful cell-based assays, this humoral response is extremely rare in adult MS and absent in classical AQP-4⁺ NMO, sharply differentiating the evolving group from both established disorders. In this review, we summarize available clinical, immunological and histopathological data on patients with MOG⁺ CNS demyelinating disease. By comparing this clearly distinct cohort to AQP-4⁺ NMO as well as MS, we propose that MOG⁺ CNS demyelinating disease represents a distinct novel disease entity. In addition to its diagnostic value, we furthermore provide mechanistic insight on how this peripheral anti-MOG ab response may be of pathogenetic relevance in triggering acute flares of inflammatory CNS demyelination.

Myelin Oligodendrocyte Glycoprotein: Deciphering a Target in Inflammatory Demyelinating Diseases

Myelin oligodendrocyte glycoprotein (MOG), a member of the immunoglobulin (Ig) superfamily, is a myelin protein solely expressed at the outermost surface of myelin sheaths and oligodendrocyte membranes. This makes MOG a potential target of cellular and humoral immune responses in inflammatory demyelinating diseases. Due to its late postnatal developmental expression, MOG is an important marker for oligodendrocyte maturation. Discovered about 30 years ago, it is one of the best-studied autoantigens for experimental autoimmune models for multiple sclerosis (MS). Human studies, however, have yielded controversial results on the role of MOG, especially MOG antibodies (Abs), as a biomarker in MS. But with improved detection methods using different expression systems to detect Abs in patients' samples, this is meanwhile no longer the case. Using cell-based assays with recombinant full-length, conformationally intact MOG, several recent studies have revealed that MOG Abs can be found in a subset of predominantly pediatric patients with acute disseminated encephalomyelitis (ADEM), aquaporin-4 (AQP4) seronegative neuromyelitis optica spectrum disorders (NMOSD), monophasic or recurrent isolated optic neuritis (ON), or transverse myelitis, in atypical MS and in N-methyl-d-aspartate receptor-encephalitis with overlapping demyelinating syndromes. Whereas MOG Abs are only transiently observed in monophasic diseases such as ADEM and their decline is associated with a favorable outcome, they are persistent in multiphasic ADEM, NMOSD, recurrent ON, or myelitis. Due to distinct clinical features within these diseases it is controversially disputed to classify MOG Ab-positive cases as a new disease entity. Neuropathologically, the presence of MOG Abs is characterized by MS-typical demyelination and oligodendrocyte pathology associated with Abs and complement. However, it remains unclear whether MOG Abs are a mere inflammatory bystander effect or truly pathogenetic. This article provides deeper insight into recent developments, the clinical relevance of MOG Abs and their role in the immunpathogenesis of inflammatory demyelinating disorders.

Anti-MOG antibody-positive ADEM following infectious mononucleosis due to a primary EBV infection: a case report

Background

Anti-Myelin oligodendrocyte glycoprotein (MOG) antibodies are detected in various demyelinating diseases, such as pediatric acute disseminated encephalomyelitis (ADEM), recurrent optic neuritis, and aquaporin-4 antibody-seronegative neuromyelitis optica spectrum disorder. We present a patient who developed anti-MOG antibody-positive ADEM following infectious mononucleosis (IM) due to Epstein–Barr virus (EBV) infection.

Case presentation

A 36-year-old healthy man developed paresthesia of bilateral lower extremities and urinary retention 8 days after the onset of IM due to primary EBV infection. The MRI revealed the lesions in the cervical spinal cord, the conus medullaris, and the internal capsule. An examination of the cerebrospinal fluid revealed pleocytosis. Cell-based immunoassays revealed positivity for anti-MOG antibody with a titer of 1:1024 and negativity for anti-aquaporin-4 antibody. His symptoms quickly improved after steroid pulse therapy followed by oral betamethasone. Anti-MOG antibody titer at the 6-month follow-up was negative.

Conclusions

This case suggests that primary EBV infection would trigger anti-MOG antibody-positive ADEM. Adult ADEM patients can be positive for anti-MOG antibody, the titers of which correlate well with the neurological symptoms.

Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica (NMO) is clinically characterized by severe optic neuritis and transverse myelitis, but recent studies with anti-aquaporin-4-antibody specific to NMO have revealed that the clinical spectrum is wider than previously thought. International consensus diagnostic criteria propose NMO spectrum disorders (NMOSD) as the term to define the entire spectrum including typical NMO, optic neuritis, acute myelitis, brain syndrome, and their combinations. NMOSD is now divided into anti-aquaporin-4-antibody-seropositive NMOSD and -seronegative NMOSD (or unknown serostatus). MR imaging and optical coherence tomography are indispensable in the diagnosis and evaluation of NMOSD. This article reviews the clinical and MR imaging findings of anti-aquaporin-4-antibody-seropositive and anti-myelin oligodendrocyte glycoprotein-antibody-seropositive NMOSD.

Anti-myelin Oligodendrocyte Glycoprotein Antibodies in a Patient with Recurrent Optic Neuritis Involving the Cerebral White Matter and Brainstem

We herein report a case of recurrent optic neuritis involving the cerebral white matter and brainstem in a patient positive for anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. The patient had an initial attack at 24 years of age. Optic neuritis recurred over 14 years, and she was admitted to our neurology unit at 38 years of age. She showed bilateral optic neuritis, high-intensity lesions in the cerebral white matter and brainstem on T2 MRI with contrast enhancement, and elevated serum anti-MOG antibodies. Immunotherapy improved the MRI lesions. Recurrent optic neuritis in patients with anti-MOG antibodies may thus involve the cerebral white matter and brainstem.

The clinical spectrum associated with myelin oligodendrocyte glycoprotein antibodies (anti-MOG-Ab) in Thai patients

BACKGROUND

Myelin oligodendrocyte glycoprotein (anti-MOG) antibody was reported in anti-aquaporin-4 (anti-AQP4) seronegative neuromyelitis optica spectrum disorders (NMOSD) patients.

OBJECTIVES

To describe clinical phenotypes associated with anti-MOG.

METHODS

Seventy consecutive Thai patients with inflammatory idiopathic demyelinating central nervous system disorders (IIDCD) who were previously anti-AQP4 seronegative were tested for anti-MOG.

RESULTS

Anti-MOG was positive in six patients, representing 20.7% of the IIDCD anti-AQP4 seronegative patients with a non-multiple sclerosis phenotype, and most had relapses. All first presented with optic neuritis with good visual recovery after treatment.

CONCLUSIONS

Anti-MOG positive patients may have manifestations that mimic NMOSD but differ in their course and prognosis from anti-AQP4 positive NMOSD.