The clinical spectrum and incidence of anti-MOG-associated acquired demyelinating syndromes in children and adults

Paediatric MOG-antibody disease presenting with intracranial hypertension and unilateral vision loss without radiological evidence of optic neuritis

Intracranial hypertension (IH) is poorly described in paediatric myelin oligodendrocyte glycoprotein antibody disease (MOGAD). We describe a unique case of seropositive MOGAD in an obese 13-year-old boy who presented with an isolated IH, bilateral optic disc swelling and sudden-onset complete vision loss in one eye without radiological evidence of optic nerve involvement. Treatment with intravenous methylprednisolone combined with an emergency shunt fully restored vision and resolved the optic disc swelling. This report adds to the growing body of evidence suggesting that obese children presenting with isolated IH should be investigated for MOGAD, and the importance of managing IH during MOGAD.

Attack phenotypes and disease course in pediatric MOGAD

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune demyelinating condition that affects children differently than adults. We performed a literature review to assess the presentation and clinical course of pediatric MOGAD. The most common initial phenotype is acute disseminated encephalomyelitis, especially among children younger than five years, followed by optic neuritis (ON) and/or transverse myelitis. Approximately one-quarter of children with MOGAD have at least one relapse that typically occurs within three years of disease onset and often includes ON, even if ON was not present at onset. Clinical risk factors for a relapsing course have not been elucidated.

MOG Antibody-Associated Disease and Thymic Hyperplasia: From the National Multiple Sclerosis Society Case Conference Proceedings

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described CNS inflammatory disorder that may manifest with optic neuritis, myelitis, seizures, and/or acute disseminated encephalomyelitis. While MOG-specific antibodies in patients with MOGAD are IgG1, a T-cell-dependent antibody isotype, immunologic mechanisms of this disease are not fully understood. Thymic hyperplasia can be associated with certain autoimmune diseases. In this report we describe a case of MOGAD associated with thymic hyperplasia in a young adult.

The Potential Pathogenicity of Myelin Oligodendrocyte Glycoprotein Antibodies in the Optic Pathway

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an acquired inflammatory demyelinating disease with optic neuritis (ON) as the most frequent clinical symptom. The hallmark of the disease is the presence of autoantibodies against MOG (MOG-IgG) in the serum of patients. Whereas the role of MOG in the experimental autoimmune encephalomyelitis animal model is well-established, the pathogenesis of the human disease and the role of human MOG-IgG is still not fully clear.

EVIDENCE ACQUISITION

PubMed was searched for the terms "MOGAD," "optic neuritis," "MOG antibodies," and "experimental autoimmune encephalomyelitis" alone or in combination, to find articles of interest for this review. Only articles written in English language were included and reference lists were searched for further relevant papers.

RESULTS

B and T cells play a role in the pathogenesis of human MOGAD. The distribution of lesions and their development toward the optic pathway is influenced by the genetic background in animal models. Moreover, MOGAD-associated ON is frequently bilateral and often relapsing with generally favorable visual outcome. Activated T-cell subsets create an inflammatory environment and B cells are necessary to produce autoantibodies directed against the MOG protein. Here, pathologic mechanisms of MOG-IgG are discussed, and histopathologic findings are presented.

CONCLUSIONS

MOGAD patients often present with ON and harbor antibodies against MOG. Furthermore, pathogenesis is most likely a synergy between encephalitogenic T and antibody producing B cells. However, to which extent MOG-IgG are pathogenic and the exact pathologic mechanism is still not well understood.

Diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease: International MOGAD Panel proposed criteria

Serum antibodies directed against myelin oligodendrocyte glycoprotein (MOG) are found in patients with acquired CNS demyelinating syndromes that are distinct from multiple sclerosis and aquaporin-4-seropositive neuromyelitis optica spectrum disorder. Based on an extensive literature review and a structured consensus process, we propose diagnostic criteria for MOG antibody-associated disease (MOGAD) in which the presence of MOG-IgG is a core criterion. According to our proposed criteria, MOGAD is typically associated with acute disseminated encephalomyelitis, optic neuritis, or transverse myelitis, and is less commonly associated with cerebral cortical encephalitis, brainstem presentations, or cerebellar presentations. MOGAD can present as either a monophasic or relapsing disease course, and MOG-IgG cell-based assays are important for diagnostic accuracy. Diagnoses such as multiple sclerosis need to be excluded, but not all patients with multiple sclerosis should undergo screening for MOG-IgG. These proposed diagnostic criteria require validation but have the potential to improve identification of individuals with MOGAD, which is essential to define long-term clinical outcomes, refine inclusion criteria for clinical trials, and identify predictors of a relapsing versus a monophasic disease course.

The epidemiology and burden of neuromyelitis optica spectrum disorder, multiple sclerosis, and MOG antibody-associated disease in a province in Thailand: A population-based study

BACKGROUND

Central nervous system inflammatory demyelinating diseases (CNSIDDs) have notable interracial heterogeneity. The epidemiology of CNSIDDs in Thailand, a mainland Southeast Asian country, is unknown.

OBJECTIVES

To determine the cumulative incidence, point prevalence, and disease burden of neuromyelitis optica spectrum disorder (NMOSD) and other CNSIDDs in Thailand using population-based data of Chumphon.

METHODS

Searching for CNSIDD patients at a public secondary care hospital in Chumphon, the only neurology center in the province, from January 2016 to December 2021 was implemented using relevant ICD-10-CM codes. All diagnoses were individually ascertained by a retrospective chart review. Cumulative incidence, point prevalence, attack rate, mortality rate, and disability-adjusted life years (DALYs) were calculated.

RESULTS

Aquaporin 4-IgG-positive NMOSD was the most prevalent CNSIDD in the Thai population at 3.08 (1.76-5.38) per 100,000 persons. The prevalence of multiple sclerosis (MS) followed at 0.77 (0.26-2.26) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) at 0.51(0.14-1.87) per 100,000 adults. In the pediatric population, the incidence of acute disseminated encephalomyelitis was 0.28 (0.08-1.02) per 100,000 persons/year. Among other idiopathic demyelinating diseases, idiopathic optic neuritis had the highest incidence at 0.58 (0.24-0.92) per 100,000 persons/year, followed by acute transverse myelitis at 0.44 (0.14-0.74). Idiopathic demyelinating brainstem syndrome was also observed at 0.04 (0.01-0.25) per 100,000 persons/year. Although most had a fair recovery, disability was worst among NMOSD patients with DALYs of 3.61 (3.00-4.36) years per 100,000 persons. Mortality rate was the highest in NMOSD as well.

CONCLUSION

CNSIDDs are rare diseases in Thailand. The prevalence is comparable to that of East Asian populations. A nationwide CNSIDDs registry would better elaborate the epidemiology of these diseases.

MOG antibody-associated encephalitis in adult: clinical phenotypes and outcomes

BACKGROUND

We investigated the clinical characteristics and outcomes of myelin oligodendrocyte glycoprotein (MOG) antibody-associated autoimmune encephalitis (MOGAE) in adult patients.

METHODS

From an institutional cohort, we analysed adult patients with MOGAE followed-up for more than 1 year. Disease severity was assessed using the modified Rankin scale (mRS) and Clinical Assessment Scale in Autoimmune Encephalitis scores. Immunotherapy profiles, outcomes and disease relapses were evaluated along with serial brain MRI data.

RESULTS

A total of 40 patients were enrolled and categorised into cortical encephalitis (18 patients), limbic encephalitis (LE, 5 patients) and acute disseminated encephalomyelitis (ADEM, 17 patients). 80.0% of patients achieved good clinical outcomes (mRS 0‒2) and 40.0% relapsed. The LE subtype was associated with an older onset age (p=0.004) and poor clinical outcomes (p=0.014) than the other subtypes but with a low rate of relapse (0.0%). 21/25 (84.0%) relapse attacks were associated with an absence or short (≤6 months) immunotherapy maintenance. On MRI, the development of either diffuse cerebral or medial temporal atrophy within the first 6 month was correlated with poor outcomes. MOG-antibody (MOG-Ab) was copresent with anti-N-methyl-D-aspartate receptor (NMDAR)-antibody in 13 patients, in whom atypical clinical presentation (cortical encephalitis or ADEM, p<0.001) and disease relapse (46.2% vs 0.0%, p<0.001) were more frequent compared with conventional NMDAR encephalitis without MOG-Ab.

CONCLUSIONS

Outcomes are different according to the three phenotypes in MOGAE. Short immunotherapy maintenance is associated with relapse, and brain atrophy was associated with poor outcomes. Patients with dual antibodies of NMDAR and MOG have a high relapse rate.

[Clinical features and modern diagnostic criteria of the disease associated with myelin oligodendrocyte glycoprotein antibody disease]

Demyelinating disease of the central nervous system associated with antibodies to myelin oligodendrocyte glycoprotein (MOGAD) has been proposed to be distinguished from neuromyelitis optica spectrum disorders (NMOSD) into a separate nosological form. The basis for the recognition of nosological independence was the presence of clinical features of this disease and the detection of a specific biomarker in the blood serum of patients - IgG class antibodies to MOG. The article summarizes the current data on the clinical and radiological phenotypes of MOGAD in children and adults and the features of the course of the disease. The requirements for the laboratory diagnosis of the disease and diagnostic criteria for MOGAD proposed by an international group of experts in 2023 are given.

Optic neuritis and autoimmune optic neuropathies: advances in diagnosis and treatment

Optic neuritis is an inflammatory optic neuropathy that is commonly indicative of autoimmune neurological disorders including multiple sclerosis, myelin-oligodendrocyte glycoprotein antibody-associated disease, and neuromyelitis optica spectrum disorder. Early clinical recognition of optic neuritis is important in determining the potential aetiology, which has bearing on prognosis and treatment. Regaining high-contrast visual acuity is common in people with idiopathic optic neuritis and multiple sclerosis-associated optic neuritis; however, residual deficits in contrast sensitivity, binocular vision, and motion perception might impair vision-specific quality-of-life metrics. In contrast, recovery of visual acuity can be poorer and optic nerve atrophy more severe in individuals who are seropositive for antibodies to myelin oligodendrocyte glycoprotein, AQP4, and CRMP5 than in individuals with typical optic neuritis from idiopathic or multiple-sclerosis associated optic neuritis. Key clinical, imaging, and laboratory findings differentiate these disorders, allowing clinicians to focus their diagnostic studies and optimise acute and preventive treatments. Guided by early and accurate diagnosis of optic neuritis subtypes, the timely use of high-dose corticosteroids and, in some instances, plasmapheresis could prevent loss of high-contrast vision, improve contrast sensitivity, and preserve colour vision and visual fields. Advancements in our knowledge, diagnosis, and treatment of optic neuritis will ultimately improve our understanding of autoimmune neurological disorders, improve clinical trial design, and spearhead therapeutic innovation.

Frequency of myelin oligodendrocyte glycoprotein antibodies in pediatric onset multiple sclerosis

BACKGROUND

Myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) are associated with acute demyelinating syndromes and only rarely detected in multiple sclerosis (MS). As MOG-Ab associated disease is common in childhood, we speculated young patients might be more likely to produce MOG-Ab and investigated the frequency of MOG-Ab seropositivity in pediatric onset MS (POMS).

MATERIAL AND METHODS

Patients who experienced their first acute demyelinating event before age 18 years and were diagnosed with MS during follow-up were included in this single-center study. Patient data were retrieved from clinical records. Serum samples obtained and frozen at clinical visits were analyzed for MOG-Ab by a live cell-based assay (CBA) measuring delta mean fluorescence intensity (MFI) and MFI ratio. The control group consisted of patients referred to pediatric neurology for headache or vertigo and who had no neurological disorder (n = 48). Another control group consisted of patients with systemic inflammatory disorders systemic lupus erythematosus (n = 17) and juvenile idiopathic arthritis (n = 13) diagnosed in the rheumatology clinic.

RESULTS

The patient group (n = 122, F/M: 90/32, mean age 17.8 ± 2.6 years) were initially diagnosed as: MS, 62/122 (50.8%), clinically isolated syndrome, 43/122 (35.2%), radiologically isolated syndrome, 9/122 (7.3%), and acute disseminated encephalomyelitis 8/122 (6.5%). All received the final diagnosis of POMS. Serum was sampled 22.4 ± 29.2 (0-132) months after the first episode. None of the control groups had MOG-Ab positivity while 2/122 (1.6%) POMS cases had MOG-Abs, and a third patient had positive MFI and a MFI ratio slightly below the cut-off. These three patients' initial and final diagnoses were MS, their annualized relapsing rates (ARRs) were 0.4-0.6, and most recent Expanded Disability Status Scale was 0.

CONCLUSION

Low titers of MOG-Ab can be detected in a small number of POMS patients at similar frequency with adult MS. Our POMS cases with MOG-Abs presented brainstem-cerebellar findings or seizures and had low ARR. Further series and longer follow-up will define whether these cases differ significantly from MOG-Ab negative POMS cases.

Details and outcomes of a large cohort of MOG-IgG associated optic neuritis

BACKGROUND

The goal of this study was to examine the temporal relationship of eye pain to visual loss and investigate whether timing of steroid treatment affects the rate and extent of visual recovery in optic neuritis (ON) from MOG-IgG associated disease (MOGAD) in a large cohort of MOGAD patients with ON.

METHODS

This is a multicenter, retrospective cohort study of consecutive MOGAD patients with ON attacks seen from 2017 to 2021 fulfilling the following criteria: (1) clinical history of ON; (2) MOG-IgG seropositivity. ON attacks were evaluated for presence/duration of eye pain, nadir of vision loss, time to intravenous methylprednisolone (IVMP) treatment, time to recovery, and final visual outcomes.

RESULTS

There were 107 patients with 140 attacks treated with IVMP and details on timing of treatment and outcomes. Eye pain was present in 125/140 (89%) attacks with pain onset a median of 3 days (range, 0 to 20) prior to vision loss. Among 46 ON attacks treated with IVMP within 2 days of onset of vision loss, median time to recovery was 4 days (range, 0 to 103) compared to 15 days (range, 0 to 365) in 94 ON attacks treated after 2 days (p = 0.004). Those treated within 2 days had less severe VA loss at time of treatment (median LogMAR VA 0.48, range, 0.1 to 3) compared to those treated after 2 days (median LogMAR VA 1.7, range, 0 to 3; p < 0.001), and were more likely to have a VA outcome of 20/40 or better (98% vs 83%, p = 0.01). After adjustment for the initial VA at time of treatment, the differences in final VA were no longer significantly different (p = 0.14). In addition, some patients were documented to recover without steroid treatment.

CONCLUSION

This study suggests that pain precedes vision loss in the majority of ON attacks and early steroids may lead to better outcomes in MOG-IgG ON, but some patients can recover without steroid treatment. Prospective randomized clinical trials are required to confirm these findings.

Early Immunotherapy and Longer Corticosteroid Treatment Are Associated With Lower Risk of Relapsing Disease Course in Pediatric MOGAD

BACKGROUND AND OBJECTIVES

We sought to identify early factors associated with relapse and outcome in paediatric-onset myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).

METHODS

In a multicenter retrospective cohort of pediatric MOGAD (≤18 years), onset features and treatment were compared in patients with monophasic vs relapsing disease (including cases with follow-up ≥12 months after onset or relapse at any time) and in patients with final Expanded Disability Status Scale (EDSS) 0 vs ≥1 at last follow-up (including cases with follow-up >3 months after last event or EDSS0 at any time). Multivariable logistic regression models were used to evaluate factors associated with relapsing disease course and EDSS ≥ 1 at final follow-up.

RESULTS

Seventy-five children were included (median onset age 7 years; median 30 months of follow-up). Presentation with acute disseminated encephalomyelitis was more frequent in children aged 8 years or younger (66.7%, 28/42) than in older patients (30.3%, 10/33) (p = 0.002), whereas presentation with optic neuritis was more common in children older than 8 years (57.6%, 19/33) than in younger patients (21.4%, 9/42) (p = 0.001). 40.0% (26/65) of patients relapsed. Time to first relapse was longer in children aged 8 years or younger than in older patients (median 18 vs 4 months) (p = 0.013). Factors at first event independently associated with lower risk of relapsing disease course were immunotherapy <7 days from onset (6.7-fold reduced odds of relapsing course, OR 0.15, 95% CI 0.03-0.61, p = 0.009), corticosteroid treatment for ≥5 weeks (6.7-fold reduced odds of relapse, OR 0.15, 95% CI 0.03-0.80, p = 0.026), and abnormal optic nerves on onset MRI (12.5-fold reduced odds of relapse, OR 0.08, 95% CI 0.01-0.50, p = 0.007). 21.1% (15/71) had EDSS ≥ 1 at final follow-up. Patients with a relapsing course had a higher proportion of final EDSS ≥ 1 (37.5%, 9/24) than children with monophasic disease (12.8%, 5/39) (p = 0.022, univariate analysis). Each 1-point increment in worst EDSS at onset was independently associated with 6.7-fold increased odds of final EDSS ≥ 1 (OR 6.65, 95% CI 1.33-33.26, p = 0.021).

DISCUSSION

At first attack of pediatric MOGAD, early immunotherapy, longer duration of corticosteroid treatment, and abnormal optic nerves on MRI seem associated with lower risk of relapse, whereas higher disease severity is associated with greater risk of final disability (EDSS ≥ 1).

Myelin oligodendrocyte glycoprotein antibody-associated disease in children: Are there MRI predictors of relapse?

BACKGROUND AND PURPOSE

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is increasingly recognized in children. Some children have isolated disease while others relapse. The study evaluates clinical, demographic and imaging features children with positive anti-MOG antibodies comparing to previously reported findings and correlate patterns on MR imaging with a relapsing course in MOGAD.

MATERIAL AND METHODS

All pediatrics patients with serum anti-MOG antibodies were reviewed. Demographic, clinical, and imaging data were evaluated. Patients with a relapsing course were compared to those with a single event. We assessed initial MR images of the brain, orbits and spine obtained at the onset of clinical symptoms, whether performed at our institution or elsewhere.

RESULTS

Thirty patients were included, fourteen with a single event and sixteen with more than one clinical event. The mean age was 8.1 years, with a mean follow-up of 58 months (range of 0.67 to 238 months). The relapsing patients had a mean of 3.5 relapses (range 2-12). 55% of patients had long segment optic nerve lesions, 53% of patients had cortical or peripheral white matter lesions, and 46% of patients had thalamic lesions. 43% of patients had spinal cord lesions, with 39% involving the central cord and 26% with long segment involvement. The imaging features between the groups were not statistically significant.

CONCLUSION

There were no distinguishing features in relapsing versus non-relapsing patients. In the absence of any predictive characteristics for future relapse, patients should have regular clinical and imaging follow up.

Acute Inflammatory Diseases of the Central Nervous System After SARS-CoV-2 Vaccination

BACKGROUND AND OBJECTIVES

Acute inflammatory CNS diseases include neuromyelitis optica spectrum disorders (NMOSDs) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Both MOGAD and acute disseminated encephalomyelitis (ADEM) have been reported after vaccination. Consequently, the mass SARS-CoV-2 vaccination program could result in increased rates of these conditions. We described the features of patients presenting with new acute CNS demyelination resembling NMOSDs or MOGAD within 8 weeks of SARS-CoV-2 vaccination.

METHODS

The study included a prospective case series of patients referred to highly specialized NMOSD services in the UK from the introduction of SARS-CoV-2 vaccination program up to May 2022. Twenty-five patients presented with new optic neuritis (ON) and/or transverse myelitis (TM) ± other CNS inflammation within 8 weeks of vaccination with either AstraZeneca (ChAdOx1S) or Pfizer (BNT162b2) vaccines. Their clinical records and paraclinical investigations including MRI scans were reviewed. Serologic testing for antibodies to myelin oligodendrocyte glycoprotein (MOG) and aquaporin 4 (AQP4) was performed using live cell-based assays. Patients' outcomes were graded good, moderate, or poor based on the last clinical assessment.

RESULTS

Of 25 patients identified (median age 38 years, 14 female), 12 (48%) had MOG antibodies (MOGIgG+), 2 (8%) had aquaporin 4 antibodies (AQP4IgG+), and 11 (44%) had neither. Twelve of 14 (86%) antibody-positive patients received the ChAdOx1S vaccine. MOGIgG+ patients presented most commonly with TM (10/12, 83%), frequently in combination with ADEM-like brain/brainstem lesions (6/12, 50%). Transverse myelitis was longitudinally extensive in 7 of the 10 patients. A peak in new MOGAD cases in Spring 2021 was attributable to postvaccine cases. Both AQP4IgG+ patients presented with brain lesions and TM. Four of 6 (67%) seronegative ChAdOx1S recipients experienced longitudinally extensive TM (LETM) compared with 1 of 5 (20%) of the BNT162b2 group, and facial nerve inflammation was reported only in ChAdOx1S recipients (2/5, 40%). Guillain-Barre syndrome was confirmed in 1 seronegative ChAdOx1S recipient and suspected in another.

DISCUSSION

ChAdOx1S was associated with 12/14 antibody-positive cases, the majority MOGAD. MOGAD patients presented atypically, only 2 with isolated ON (1 after BNT162b2 vaccine) but with frequent ADEM-like brain lesions and LETM. Within the seronegative group, phenotypic differences were observed between ChAdOx1S and BNT162b2 recipients. These observations might support a causative role of the ChAdOx1S vaccine in inflammatory CNS disease and particularly MOGAD. Further study of this cohort could provide insights into vaccine-associated immunopathology.

Clinical characteristics and prognosis of pediatric myelin oligodendrocyte glycoprotein antibody-associated diseases in China

BACKGROUND

Research on myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated disease (MOGAD) among Chinese children is relatively rare. Therefore, this study aimed to explore and analyze the clinical characteristics and prognoses of Chinese children with acquired demyelinating syndromes (ADSs) who tested positive or negative for MOG-Ab.

METHODS

The clinical data of children with MOGAD who were treated in the Department of Neurology at Shanghai Children's Hospital from January 2017 to October 2021 were retrospectively collected.

RESULTS

Among 90 children with ADSs, 30 were MOG-Ab-positive, and 60 were MOG-Ab-negative. MOG-Ab-positive children experienced more prodromal infections than did MOG-Ab-negative children (P < 0.05). Acute disseminated encephalomyelitis was the most common ADSs in both groups. There were ten cases of a rebound increase in MOG-Ab titers. There were significant differences in the MOG titer-related prognosis and disease time course between the disease relapse group and the non-relapse group (P < 0.01). Among the MOG-Ab-positive patients, the most affected brain areas detected via magnetic resonance imaging (MRI) were the temporal lobe, cerebellar hemispheres, brainstem, and periventricular lesions. The most common shapes of the lesions were commas, triangles, or patches. The average improvement time based on brain MRI was much longer in MOG-Ab-positive than in MOG-Ab-negative children (P < 0.05). The initial treatment time correlated with the disease time course, and the prognosis may be affected by the disease time course and serum MOG-Ab titer (P < 0.05).

CONCLUSION

The clinical characteristics and imaging features of ADSs differed between MOG-Ab-positive and MOG-Ab-negative children. In addition to existing treatment plans, additional diagnoses and treatment plans should be developed to reduce recurrence and improve the prognoses of children with MOGAD.

Clinical characteristics and associated factors of pediatric acute disseminated encephalomyelitis patients with MOG antibodies: a retrospective study in Hangzhou, China

Background

To explore the clinical characteristics and related factors of children with acute disseminated encephalomyelitis (ADEM) with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody.

Methods

A retrospective study was conducted and enrolled pediatric ADEM patients who underwent serum MOG antibody detection from May 2017 to August 2020. The patients were divided into two groups: MOG- immunoglobulin G (IgG) positive (n = 35) and MOG-IgG negative (n = 50). We analyzed the clinical characteristics of MOG-IgG-positive ADEM pediatric patients and conducted a comparative analysis between the two groups.

Results

Thirty-five patients (21 males and 14 females) in the MOG-IgG-positive group with encephalopathy, multifocal neurological symptoms, and typical magnetic resonance imaging (MRI) abnormalities were enrolled. They usually had a favorable outcome, while some suffered from relapse. Compared to the MOG-IgG-negative group, MOG-IgG-positive ADEM patients had a longer disease duration (median: 10 vs. 6 days), more meningeal involvement (31.4% vs. 8%) and frontal lobe involvement (82.8% vs. 68%), higher relapse rates (14.3% vs. 2%), lower serum tumor necrosis factor (1–12.4 pg/ml, median 1.7 vs. 1–34 pg/ml, median 2.2) and interferon-gamma (1–9.4 pg/ml, median 1.3 vs. 1–64 pg/ml, median 3) (P < 0.05, respectively). Multivariate logistic regression analysis showed that the longer disease duration, meningeal involvement and frontal lobe involvement were the correlated factors of patients with ADEM with MOG antibody (P < 0.05).

Conclusions

Our findings provide clinical evidence that MOG-IgG positivity is associated with longer disease duration, meningeal involvement, and frontal lobe involvement.

Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Inflammatory myelopathies can manifest with a combination of motor, sensory and autonomic dysfunction of variable severity. Depending on the underlying etiology, the episodes of myelitis can recur, often leading to irreversible spinal cord damage and major long-term disability. Three main demyelinating disorders of the central nervous system, namely multiple sclerosis (MS), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4+NMOSD) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD), can induce spinal cord inflammation through different pathogenic mechanisms, resulting in a more or less profound disruption of spinal cord integrity. This ultimately translates into distinctive clinical-MRI features, as well as distinct patterns of disability accrual, with a step-wise worsening of neurological function in MOGAD and AQP4+NMOSD, and progressive disability accrual in MS. Early recognition of the specific etiologies of demyelinating myelitis and initiation of the appropriate treatment is crucial to improve outcome. In this review article we summarize and compare the clinical and imaging features of spinal cord involvement in these three demyelinating disorders, both during the acute phase and over time, and outline the current knowledge on the expected patterns of disability accrual and outcomes. We also discuss the potential implications of these observations for patient management and counseling.

Seroprevalence of MOG and AQP4 Antibodies and Outcomes in an Indian Cohort of Pediatric Acquired Demyelinating Syndromes

This study aimed to determine the seropositivity of myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) and aquaporin-4 antibodies (AQP4-Ab) and outcomes in children with acquired demyelinating syndromes (ADSs). Children (6 months-15 years) with suspected ADS were enrolled and tested for MOG-Ab and AQP4-Ab prospectively over 18 months at a tertiary care hospital in North India. Children with proven nonimmune-mediated neurological disorders were enrolled as controls. Of 79 children with suspected ADS, 66 were enrolled. Among the enrolled children with ADS, acute demyelinating encephalomyelitis (ADEM) (25) was the most common first clinical event followed by optic neuritis (ON) (20) and transverse myelitis (TM) (19; one child had ON and TM simultaneously [neuromyelitis optica spectrum disorders [NMOSDs]]), while two children had clinically isolated syndrome (CIS) apart from ON and TM. Fourteen (21.2%, confidence interval [CI] 11.3-31.1) tested positive for one antibody (12 [18.1%; 95% CI 10.5-25.5%] for MOG-Ab and 2 [3%; 95% CI 0-7.2%] for AQP4-Ab). None of the 62 controls tested positive for any antibody. The final diagnosis in those with the monophasic ADS was ADEM (21), ON (13), TM (16), and other CIS (1) while that in children with recurrent events was multiphasic disseminated encephalomyelitis (MDEM) (2), NMOSD (3), ADEM-ON (4), recurrent ON (4), and MS (2). Among those with the first event, 4/51 (7.8%; 95% CI 0.5-15.2%) were MOG-Ab positive and 2 AQP4-Ab positive, whereas 8/15 (53.3% [95% CI 28.1-78.6%]) with recurrent events (MDEM [2], ADEM-ON [4], recurrent ON [1], and recurrent TM [1]) were MOG-Ab positive. Hence, MOG-Abs are the most common antibodies detected in one in five children with pediatric ADS, especially in relapsing disease. AQP4-Abs are rare in children with ADS.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

Seroprevalence of anti-myelin oligodendrocyte glycoprotein antibodies in adults with myelitis

Although myelitis is the second most common presentation in adults with myelin oligodendrocyte glycoprotein (MOG) antibody‐associated disease (MOGAD), studies on MOG‐IgG seroprevalence in patients with myelitis episodes are sparse. Herein, we investigated MOG‐IgG seroprevalence in Korean adults who exhibited myelitis since 2017. Among 151 adults with acute myelitis, 11 (7.3%) tested positive for MOG‐IgG by the initial screening and 10 (6.6%) patients were finally diagnosed with MOGAD during the study period. This study is the first to provide data on MOG‐IgG seroprevalence in adults with myelitis and supports the clinical utility and importance of MOG‐IgG testing in myelitis episodes.

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.

Pediatric Acquired Demyelinating Disorders

PURPOSE OF REVIEW

This article reviews the clinical presentation, diagnostic evaluation, treatment, and prognosis of the most common monophasic and relapsing acquired demyelinating disorders presenting in childhood.

RECENT FINDINGS

Our understanding of neuroimmune disorders of the central nervous system is rapidly expanding. Several clinical and paraclinical factors help to inform the diagnosis and ultimately the suspicion for a monophasic versus relapsing course, including the age of the patient (prepubertal versus postpubertal), presence or absence of clinical encephalopathy, identification of serum autoantibodies (eg, myelin oligodendrocyte glycoprotein [MOG] and aquaporin-4), presence of intrathecally unique oligoclonal bands, and location/extent of radiologic abnormalities. Collaborative international research efforts have facilitated understanding of the safety and efficacy of currently available immunotherapies in children with acquired demyelinating disorders, particularly multiple sclerosis.

SUMMARY

Although many of the demyelinating disorders presented in this article can affect children and adults across the age spectrum, the clinical and radiologic phenotypes, treatment considerations, and long-term prognoses are often distinct in children.

SARS-COV-2 a trigger of myelin oligodendrocyte glycoprotein-associated disorder

SARS-COV-2 frequently cause neurological disorders and is sometimes associated with onset of autoimmune diseases affecting the nervous system. Over recent years, a rare but distinct diagnosis designated myelin oligodendrocyte glycoprotein-associated disorder (MOGAD) has been recognized in patients with attacks of optic neuritis, myelitis, or encephalomyelitis and increased levels of anti-MOG antibodies. The cause of MOGAD is unknown. However, there have been reports of single cases of MOGAD in patients with Covid-19 infection. We report a series of SARS-CoV-2 positive patients that developed MOGAD, but a homology search did not support a cross-reactive immune response to SARS-CoV-2 spike-protein and MOG.

Comparison of clinical and radiological characteristics in autoimmune GFAP astrocytopathy, MOGAD and AQP4-IgG+ NMOSD mimicking intracranial infection as the initial manifestation

OBJECTIVE

Several autoimmune CNS inflammatory diseases, including autoimmune glial fibrillary acidic protein astrocytopathy (A-GFAP-A), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and aquaporin-4-immunoglobulin-G-positive neuromyelitis optica spectrum disorders (AQP4-IgG⁺NMOSD) often presented initially with similar symptoms mimicking intracranial infection, are not easy to be differentiated during early-onset lacking the detection of autoantibody.

METHODS

In our single-center cohorts, those patients mimicking intracranial infection as initial symptoms, including 9 with A-GFAP-A, 17 with MOGAD and 11 with AQP4-IgG⁺NMOSD, were retrospectively included. The autoantibodies were detected by cell-based assays. The clinical, immunological and radiological characteristics were summarized.

RESULTS

In the cohort, tremor and positive Kernig's sign were predominated in A-GFAP-A (44.4% and 77.8%, respectively) over MOGAD (5.9%, p = 0.034; 29.4%, p = 0.038) and AQP4-IgG⁺NMOSD (0, p = 0.026; 18.2%, p = 0.022). Ten patients (A-GFAP-A, 4; MOGAD, 5; AQP4-IgG⁺NMOSD, 1) were initially misdiagnosed as tubercular or viral meningoencephalitis, however, resistant to empiric anti-tuberculosis or anti-viral treatment, and finally were in partial or complete remission with the immunotherapy when adjusted treatments. On cerebrospinal fluid (CSF) examination, white blood cell counts in CSF was higher in A-GFAP-A cohort (median, 90×10⁶/L [IQR, 41-209]) compared to AQP4-IgG⁺ NMOSD (median, 6 × 10⁶/L [IQR, 1-10], p = 0.018). Importantly, the higher increase in CSF protein (1319 mg/L [IQR, 1035-1519]), lactate dehydrogenase (LDH, 53.9 ± 37.2 U/L), lactic acid (3.50 ± 0.88 mmol/L), IgG (130.9 ± 60.4 mg/L), IgM (8.6 ± 6.1 mg/L) and IgA (23.0 ± 11.4 mg/L) levels in A-GFAP-A was found compared to MOGAD (CSF protein: 441 mg/L [IQR, 330-776], p = 0.004; LDH: 53.9  ±  37.2 U/L, p = 0.005; lactic acid: 2.15 ± 0.62 mmol/L, p = 0.001; IgG: 77.9 ± 71.3 mg/L, p = 0.018; IgM, 2.7 ± 2.9 mg/L, p = 0.015) and AQP4-IgG⁺ NMOSD (CSF protein: 386 mg/L [IQR, 369-453], p = 0.002; LDH: 23.7 ± 11.0 U/L, p = 0.048; lactic acid: 2.40  ±  0.66 mmol/L, p = 0.040; IgG, 53.2 ± 30.3 mg/L, p = 0.015; IgM, 2.1 ± 3.9 mg/L, p = 0.004; IgA, 5.2 ± 5.0 mg/L, p < 0.001). Of Note, smaller (< 2 cm), symmetrical lesions in ganglia and thalamus (5/8, 62.5%) were showed in over half of the A-GFAP-A patients (5/8, 62.5%), but never in MOGAD (0%, p = 0.001) and AQP4-IgG⁺NMOSD (0%, p = 0.026). In addition, diffuse meningeal enhancement was more common in A-GFAP-A (8, 88.9%) compared to MOGAD (5, 29.4%, p = 0.011) and AQP4-IgG⁺NMOSD (1/6, 16.7%, p = 0.011), respectively. Acute disseminated encephalomyelitis (ADEM) -like lesions occurred more frequently in MOGAD (6/16, 37.5%) but never in A-GFAP-A and AQP4-IgG⁺NMOSD (p = 0.02).

CONCLUSION

Our study demonstrates that several distinct features including the symptom of tremor, higher CSF immunological profiles, bilateral symmetrical lesions in ganglia, and diffuse meningeal enhancement are frequent in A-GFAP-A, whereas ADEM-like lesions seem to occur mainly in MOGAD. These signs provide crucial clinical implications in differential diagnosis for those mimicking intracranial infection as initial symptoms. Clinicians should consider the possibility of these autoimmune CNS inflammatory diseases masquerading as intracranial infection.

Clinical and Radiological Features of Myelin Oligodendrocyte Glycoprotein-Associated Myelitis in Adults

Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have recently been established as a biomarker for MOG-antibody-associated disease (MOGAD), which is a distinct demyelinating disease of the central nervous system. Among the diverse clinical phenotypes of MOGAD, myelitis is the second-most-common presentation in adults, followed by optic neuritis. While some features overlap, there are multiple reports of distinctive clinical and radiological features of MOG-IgG-associated myelitis, which are useful for differentiating MOGAD from both multiple sclerosis and neuromyelitis optica spectrum disorder. In this review we summarize the clinical and radiographic characteristics of MOG-IgG-associated myelitis with a particular focus on adult patients.

COVID-19 Vaccine-A Potential Trigger for MOGAD Transverse Myelitis in a Teenager-A Case Report and a Review of the Literature

MOGAD-transverse myelitis is a rare disorder in children and adults, but with a higher incidence in pediatric patients. We report a case of MOGAD-transverse myelitis in a boy who was admitted to hospital with bilateral motor deficit of the lower limbs associated with the impossibility of defecating and urinating. The symptoms progressively developed with severe fatigue within the week prior to admission, with the impossibility to stand occurring 36 h before admission. The anamnesis found that he was vaccinated for COVID-19 approximately 6 weeks before admission to our clinic. The laboratory tests revealed a normal complete cellular blood count, without any signs of inflammation or infection, except for both cryoglobulins and IgG anti-MOG antibodies. MRI showed a T2 hypersignal on vertebral segments C2-C5, Th2-Th5 and Th7-Th11, confirming the diagnosis of longitudinally extensive transverse myelitis. The patient received intravenous high-dose methylprednisolone (1 g) for 5 days, associated with prophylactic antibiotic treatment, subcutaneous low-molecular-weight heparin and other supportive treatment. The patient was discharged on the 12th day of admission, able to walk without support and with no bladder or bowel dysfunction. We can conclude that an early diagnosis was essential for improving the patient's long-term outcome.

Monoclonal Antibody Therapies Beyond Complement for NMOSD and MOGAD

Aquaporin-4 (AQP4)-IgG seropositive neuromyelitis optica spectrum disorders (AQP4-IgG seropositive NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD) are inflammatory demyelinating disorders distinct from each other and from multiple sclerosis (MS).While anti-CD20 treatments can be used to treat MS and AQP4-IgG seropositive NMOSD, some MS medications are ineffective or could exacerbate AQP4-IgG seropositive NMOSD including beta-interferons, natalizumab, and fingolimod. AQP4-IgG seropositive NMOSD has a relapsing course in most cases, and preventative maintenance treatments should be started after the initial attack. Rituximab, eculizumab, inebilizumab, and satralizumab all have class 1 evidence for use in AQP4-IgG seropositive NMOSD, and the latter three have been approved by the US Food and Drug Administration (FDA). MOGAD is much more likely to be monophasic than AQP4-IgG seropositive NMOSD, and preventative therapy is usually reserved for those who have had a disease relapse. There is a lack of any class 1 evidence for MOGAD preventative treatment. Observational benefit has been suggested from oral immunosuppressants, intravenous immunoglobulin (IVIg), rituximab, and tocilizumab. Randomized placebo-controlled trials are urgently needed in this area.

Incidence of paediatric multiple sclerosis and other acquired demyelinating syndromes: 10-year follow-up surveillance study

AIM

To describe a 10-year follow-up of children (<16y) with acquired demyelinating syndromes (ADS) from a UK-wide prospective surveillance study.

METHOD

Diagnoses were retrieved from the patients' records via the patients' paediatric or adult neurologist using a questionnaire. Demyelinating phenotypes at follow-up were classified by an expert review panel.

RESULTS

Twenty-four out of 125 (19.2%) children (64 males, 61 females; median age 10y, range 1y 4mo-15y 11mo), identified in the original study, were diagnosed with multiple sclerosis (incidence of 2.04/million children/year); 23 of 24 fulfilled 2017 McDonald criteria at onset. Aquaporin-4-antibody neuromyelitis optica spectrum disorders were diagnosed in three (2.4%, 0.26/million children/year), and relapsing myelin oligodendrocyte glycoprotein antibody-associated disease in five (4%, 0.43/million children/year). Three out of 125 seronegative patients relapsed and 85 of 125 (68%) remained monophasic over 10 years. Five of 125 patients (4%) originally diagnosed with ADS were reclassified during follow-up: three children diagnosed initially with acute disseminated encephalomyelitis were subsequently diagnosed with acute necrotising encephalopathy (RAN-binding protein 2 mutation), primary haemophagocytic lymphohistiocytosis (Munc 13-4 gene inversion), and anti-N-methyl-d-aspartate receptor encephalitis. One child initially diagnosed with optic neuritis was later diagnosed with vitamin B12 deficiency, and one presenting with transverse myelitis was subsequently diagnosed with Sjögren syndrome.

INTERPRETATION

The majority of ADS presentations in children are monophasic, even at 10-year follow-up. Given the implications for treatment strategies, multiple sclerosis and central nervous system autoantibody mimics warrant extensive investigation.

Failure of alemtuzumab therapy in three patients with MOG antibody associated disease

BACKGROUND

Myelin Oligodendrocyte Glycoprotein antibody-associated disease (MOGAD) is most classically associated in both children and adults with phenotypes including bilateral and recurrent optic neuritis (ON) and transverse myelitis (TM), with the absence of brain lesions characteristic of multiple sclerosis (MS). ADEM phenotype is the most common presentation of MOGAD in children. However, the presence of clinical phenotypes including unilateral ON and short TM in some patients with MOGAD may lead to their misdiagnosis as MS. Thus, clinically and radiologically, MOGAD can mimic MS and clinical vigilance is required for accurate diagnostic workup.

CASE PRESENTATION

We present three cases initially diagnosed as MS and then treated with alemtuzumab. Unexpectedly, all three patients did quite poorly on this medication, with a decline in their clinical status with worsening of expanded disability status scale (EDSS) and an increasing lesion load on magnetic resonance imaging of the brain. Subsequently, all three cases were found to have anti-MOG antibody in their serum.

CONCLUSIONS

These cases highlight that if a patient suspected to have MS does not respond to conventional treatments such as alemtuzumab, a search for alternative diagnoses such as MOG antibody disease may be warranted.

Para and Post-COVID-19 CNS Acute Demyelinating Disorders in Children: A Case Series on Expanding the Spectrum of Clinical and Radiological Characteristics

Viral infections can serve as a trigger for variable autoimmune, antibody-mediated demyelinating disorders. There is accumulating evidence that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, causing coronavirus disease 2019 (COVID-19) infection and responsible for the current worldwide pandemic, can lead to a cascade of immune-mediated brain and spinal cord demyelinating injuries. However, such observation in the pediatric age group was only reported in very few patients. Thus, the heterogeneous spectrum of this phenomenon in children is still unfolding. We are reporting a case series of five pediatric patients with a variety of acute central nervous system (CNS) demyelinating disorders in the context of acute or recent COVID-19 infection. A 16-year-old female with anti-myelin oligodendrocyte glycoprotein (MOG) disorder, an eight-year-old male with acute disseminated encephalomyelitis (ADEM), a 13-year-old female with neuromyelitis optica spectrum disorder (NMOSD), and two 14 and 13-year-old females with new-onset multiple sclerosis (MS) are reported, all of whom presented acutely following COVID-19 infection. We propose that para and post-infectious CNS demyelinating disorders can potentially follow acute COVID-19 infection in children. Considering SARS-CoV-2 testing as a part of diagnostic workup is possibly useful. Awareness of the presence of this phenomenon can help in the recognition and management of those patients.

Clinical predictive factors for diagnosis of MOG-IgG and AQP4-IgG related paediatric optic neuritis: a Chinese cohort study

BACKGROUND

Different glial-autoantibodies-related paediatric optic neuritis (ON) are associated with different clinical characteristics and prognosis that require different treatments. Because glial autoantibody detection is not available in some parts of the world and there is often a delay in obtaining results, clinical factors that can be used to predict the subtype of paediatric ON are needed.

METHODS

This was a single-centre retrospective cohort study. Children who presented with their first ON attack and with complete clinical data were included in the analysis. Single and multiple parameters for predicting paediatric myelin oligodendrocyte glycoprotein immunoglobin-associated ON (MOG-ON) and aquaporin-4 immunoglobin-related ON (AQP4-ON) were calculated.

RESULTS

78 paediatric patients had their first ON attack from January 2016 to December 2019, of whom 69 were included in the final analysis, including 33 MOG-ON cases, 17 AQP4-ON cases and 19 Seronegative-ON cases. For predicting paediatric MOG-ON, the most sensitive predictors were 'male or optic disc swelling (ODS) or bilateral' (sensitivity 0.97 (95% CI 0.82 to 1.00)) and 'follow-up visual acuity (VA) ≤0.1 logMAR or ODS' (sensitivity 0.97 (95% CI 0.82 to 1.00)), and the most specific factor was 'Age ≤11 y and simultaneous CNS involvement' (specificity 0.97 (95% CI 0.84 to 1.00)). For predicting paediatric AQP4-ON, the most sensitive predictor was 'Female or without ODS' (sensitivity 1.00 (95% CI 0.77 to 1.00)), and the most specific factors were Neurological history (sensitivity 0.94 (95% CI 0.83 to 0.98)) and follow-up VA >1.0 logMAR (sensitivity 0.96 (95% CI 0.86 to 0.99)).

CONCLUSION

According to our data from a Chinese paediatric cohort, using multiple parameters increases the sensitivity and specificity of diagnosing paediatric MOG-ON and AQP4-ON. These can assist clinicians in diagnosing and treating paediatric ON when glial autoantibody status is not available.

Case Report: Four Cases of Cortical/Brainstem Encephalitis Positive for Myelin Oligodendrocyte Glycoprotein Immunoglobulin G

AIM

Despite a significant improvement in the number of studies on myelin oligodendrocyte glycoprotein (MOG)-immunoglobulin G (IgG)-associated disorder (MOGAD) over the past few years, MOG-IgG-associated cortical/brainstem encephalitis remains a relatively uncommon and less-reported presentation among the MOGAD spectrum. This study aimed to report the clinical course, imaging features, and therapeutic response of MOG-IgG-associated cortical/brainstem encephalitis.

METHODS

Data of four patients who suffered from cortical encephalitis with epileptic seizures and/or brainstem encephalitis during the course of the disease were retrospectively collected and analyzed.

RESULTS

In this study, three male patients and one female patient, with a median age of onset of 21 years (ranging 20-51 years) were enrolled. An epileptic seizure was the main symptom of cortical encephalitis in these patients, while the manifestations of brainstem encephalitis were diverse. Cranial MRI demonstrated abnormal signals in unilateral or bilateral cortical or brainstem. Cerebrospinal fluid studies showed normal or mildly elevated leukocyte counts and protein levels, and a cell-based assay detected positive MOG-IgG in the serum of all patients. Two patients were misdiagnosed at the first attack, and both experienced a relapse. All of them accepted the first-line immunotherapy after a confirmed diagnosis and had a good outcome.

CONCLUSION

Early suspicion of MOG-IgG-associated encephalitis is necessary for any patient with sudden onset of seizures or symptoms of brainstem damage, especially with lesions on unilateral/bilateral cortical or brainstem on brain MRI.

Simultaneous screening for antibodies to myelin oligodendrocyte glycoprotein and aquaporin-4 in patients with optic neuritis using cell-based assay

Background: This study was aimed to test simultaneous detection of antibodies to myelin oligodendrocyte glycoprotein (MOG)/aquaporin4 (AQP4) in serum samples of patients with clinically-diagnosed optic neuritis (ON), by fixed cell-based immunofluorescence assay (CBIFA). Methods: The study involved 237 serum samples of patients with ON which were tested for MOG and AQP4 antibodies using fixed CBIFA kit which utilizes AQP4 or MOG protein transfected cells as a substrate. Results: Of 237 serum samples, 22 (9%) were positive for AQP4, 66 (28%) were positive for MOG, and 138 (58%) were negative for both AQP4 and MOG antibodies. 11 (5%) patients with clinically-diagnosed multiple sclerosis (MS) were negative for both antibodies. None of the samples were positive for both AQP4 and MOG. Among 237, 132 women [18 (13.6%) and 37 (28%)] and 105 men [4 (3.8%) and 29 (27.6%)] were positive for AQP4/MOG antibodies and remaining percentage belonged to double negative and MS. Seropositivity rate was higher in women than men. Antibodies to MOG were significantly higher than AQP4 antibodies and evenly found in all age groups. There was no ambiguous result encountered in the study. Conclusion: In this study, the seropositivity for antibodies to MOG is more than AQP4 antibody in patients with ON. Fixed CBIFA is a useful tool for laboratory diagnosis of ON in the clinical setting of neuro-ophthalmology to plan the next line of treatment management effectively.

Clinical and Magnetic Resonance Imaging Characteristics of Pediatric Acute Disseminating Encephalomyelitis With and Without Antibodies to Myelin Oligodendrocyte Glycoprotein

BACKGROUND

Myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated disorders (MOGADs) have been considered as a new inflammatory disease entity of the central nervous system (CNS) and have heterogeneous clinical and imaging presentations. Acute disseminated encephalomyelitis (ADEM) is one of the most important phenotypes. Our research is aimed to compare the clinical and magnetic resonance imaging (MRI) characteristics of ADEM with or without MOG-IgG in pediatric-acquired demyelinating syndromes (ADSs).

METHODS AND RESULTS

We retrospectively reviewed the clinical characteristics, MRI features, and outcomes of pediatric patients with ADSs from March 2017 to February 2021 in our center. MOG-IgG was analyzed by transfected cell-based assay (CBA). Among 46 children with ADEM, 21 children (11 girls and 10 boys) were positive for MOG-IgG. Headache, fever, vomiting, vertigo, ataxia, and decreased muscle strength were common in all enrolled children. No significant difference existed in demographic characteristics, symptoms at an initial episode, or laboratory cerebrospinal fluid (CSF) findings between children with MOG-IgG and children without MOG-IgG. For children with MOG-IgG seropositive ADEM, cerebral MRI showed widespread, poorly demarcated bilateral lesions, especially in cortical and subcortical white matter, and spinal MRI often showed lesions spanning more than three segments. The significant difference in MRI features between the two groups was the presence of lesions in the thalamus and cortical area (p < 0.05). Most children in both groups showed clinical improvement 1 week after immunotherapy and achieved recovery during their hospital stay. Three children with MOG-IgG and four children without MOG-IgG had one or more relapsing courses with median interattack intervals of 4 (range: 1-7) months and 10 (range: 1-24) months, respectively. New clinical symptoms and lesions on cerebral and spinal MRI were found during relapsing courses in two groups. No recurrences were recorded 6-51 months after each patient's last episode.

CONCLUSIONS

There was no significant difference in clinical characteristics between ADEM children with MOG-IgG and ADEM children without MOG-IgG. For children with MOG-IgG seropositive ADEM, cerebral MRI showed large, bilateral lesions and spinal MRI often showed lesions spanning more than three segments. Children achieved a favorable outcome regardless of MOG-IgG serostatus.

[Epidemiology of neuromyelitis optica spectrum. New and old challenges]

INTRODUCTION

This epidemiological review on neuromyelitis optica spectrum disorder (NMOSD) focuses on describing the methodologies employed in studies conducted under the 2015 NMOSD criteria and the studies conducted in Spain and Latin America, as well as examining factors related to the prognosis of the disease.

DEVELOPMENT

The methodology used in the studies varies essentially in the application of different diagnostic criteria, sources of records, antibody detection techniques and standardisation methods. However, in general terms, NMOSD is distributed worldwide with an incidence/prevalence that is higher in women than in men, and in Asian and African-American countries than in Western countries. The frequency increases in parallel to age, with a peak incidence/prevalence in the 40-59 age range. The Latin American population has particular epidemiological characteristics linked to its racial and genetic mix. Finally, epidemiological variables, such as belonging to the black race, being of older age at onset and being female, are associated with a worse functional prognosis.

CONCLUSIONS

Epidemiological data on NMOSD vary from one study to another, largely due to discrepancies in the methodological designs. Although Latin American studies are scarce, the findings described are associated with their ethnic mix. The homogenisation of criteria and the use of similar diagnostic techniques and standardisation methods must be implemented for the correct study of the epidemiology of NMOSD.

Optic neuropathies post-Covid 19 - review

The Corona virus infection started at the end of 2019 in Wuhan - China and spread rapidly throughout the world, generating the Covid 19 pandemic. The manifestations of the Covid disease were extremely varied, from a simple flu, with fever, cough, weakness, headache, joint pain, up to severe pneumonia, with severe acute respiratory syndrome (SARS-Cov2) and even death. The symptomatology of the disease, the evolution and the complications that appeared varied, depending on the associated pathology - diabetes mellitus (DM), hypertension (HT), the age and the immune status of the patient. Aim: The ocular manifestations related to Covid 19 were mostly represented by conjunctivitis, but the neurotropic character of Corona virus could justify the appearance of certain neuro-ophthalmological manifestations, such as: optic neuritis (ON), cranial nerve palsies, visual field (VF) anomalies. The aim of this paper was to research the cases of optic neuropathy post-Covid 19, published in the specialty literature between 2020 and 2022. The following were evaluated: risk factors, distribution by age group and gender, evolution and complications, as well as the clinical forms of optic neuropathies. Materials and methods: We used Google Scholar and PubMed databases to find articles on optic neuropathies related to the Covid-19 infection. We followed the articles published during the pandemic and selected 21 cases, belonging to 17 authors, irrespective of their origin and the language in which they were written. Results: 21 patients affected by ON in the Covid-19 disease, 11 women and 10 men, were mentioned. The optic neuropathies described by the authors were: retrobulbar optic neuropathy, only one associated with myelin oligodendrocyte glycoprotein (MOG), papillitis, neuroretinitis, anterior ischemic optic neuropathy (AION), out of which one arteritic anterior ischemic optic neuropathy (AAION) and the others non-arteritic anterior ischemic optic neuropathy (NAAION), one being related to pronation in an oro-tracheal intubated (OTI) patient with acute respiratory distress syndrome (ARDS). Discussions: The neuro-ophthalmological complications associated with Covid 19 disease can be severe, so the patients should be monitored continuously. Many investigations (serological, immunological and imaging exams) are necessary to exclude other etiologies of ON. Conclusions: A complete ophthalmological exam is mandatory for each patient diagnosed with Covid 19 disease, even if they have ocular manifestations or not. Abbreviations: SARS-Cov2 = severe acute respiratory syndrome; DM = Diabetes mellitus; HT = Hypertension; ON = Optic neuritis; VF = Visual field ; NS = Nervous system; CRP = C-reactive Protein; CL = cytokines; IL = interleukins; TNFɑ = tumor necrosis factor; CNS = central nervous system; ACE = angiotensin-converting enzyme; CRVO = central retinal vein occlusion; MOG = myelin oligodendrocyte glycoprotein; MOG-AD = myelin oligodendrocyte glycoprotein antibody disease; BBB = blood-brain barrier; ARDS = acute respiratory distress syndrome; IOP = intraocular pressure; CVP = central venous pressure; MSOF = multiple systems organ failure; AAION = arteritic anterior ischemic optic neuropathy; NAION = non-arteritic anterior ischemic optic neuropathy; AION = anterior ischemic optic neuropathy; OCT = optical coherence tomography; CT = computer tomography; AFG = angiofluorography; MRI = magnetic resonance imaging; ESR = erythrocyte sedimentation rate; RF = rheumatoid factor; ANA = antinuclear antibodies; ANCA = antineutrophil cytoplasmic antibodies; AQP4 = anti aquaporin 4; NMO = neuromyelitis optica; CSF = cerebrospinal fluid; OTI = oro-tracheal intubated; VA = visual acuity; ONTT = optic neuritis treatment trial; RNFL = retinal nerve fiber layer; ICU = intensive care unit; LE = left eye; RE = right eye; MS = multiple sclerosis; ICH = intracranial hypertension; BCVA = best correction visual acuity; LP = light perception; APD = afferent pupillary defect; BM = biomicroscopy; PDN = prednisone; MTX = methotrexate; MTPN = methylprednisolone; NSAID = non-steroidal anti-inflammatory drugs; CGL = cells ganglion layer; VEP = visual evoked potential; CF = counting fingers.

The changing landscape of optic neuritis: a narrative review

Optic neuritis (ON) is an inflammatory optic neuropathy that is often a harbinger of central nervous system (CNS) demyelinating disorders. ON is frequently misdiagnosed in the clinical arena, leading to either inappropriate management or diagnostic delays. As a result, patients may fail to achieve optimal recovery. The treatment response to corticosteroids and long term risk of multiple sclerosis was established in the first clinical trials conducted roughly 30 years ago. Spontaneous resolution was observed in the vast majority of patients and intravenous high-dose corticosteroids hastened recovery; half of the patients eventually developed multiple sclerosis. Over the ensuing decades, the number of inflammatory conditions associated with ON has significantly expanded exposing substantial variability in the prognosis, treatment, and management of ON patients. ON subtypes can frequently be distinguished by distinct clinical, serological, and radiological profiles allowing expedited and specialized treatment. Guided by an increased understanding of the immunopathology underlying optic nerve and associated CNS injuries, novel disease management strategies are emerging to minimize vision loss, improve long-term surveillance strategies, and minimize CNS injury and disability. Knowledge regarding the clinical signs and symptoms of different ON subtypes is essential to guide acute therapy, prognosticate recovery, accurately identify underlying CNS inflammatory disorders, and facilitate study design for the next generation of clinical and translational trials.

Clinical characteristics, disease course, and outcomes of paediatric patients with myelin oligodendrocyte glycoprotein-Ab associated disease: A retrospective clinical study

OBJECTIVE

To delineate the outcomes of paediatric patients with myelin oligodendrocyte glycoprotein antibody disease (MOGAD).

METHODS

We retrospectively analyzed the clinical characteristics, treatment, and outcomes of 34 paediatric patients with MOGAD from July 2015 to January 2020.

RESULTS

The median age at disease onset was 75.5 months (range: 19-170 months). The female-to-male ratio was 1:1.1. The median follow-up duration was 34.5 months (range: 14-63 months). Acute disseminated encephalomyelitis (ADEM) was the most common initial phenotype (52.9%), followed by optic neuritis (ON) (20.6%). Children with ADEM were younger than those with ON (P = 0.045). Twenty-eight (82.4%) and 18 (56.3%) children had abnormal brain and spinal magnetic resonance imaging, respectively, during the first acute attack. MOG-abs titers in children with ON were statistically higher than those in children with ADEM (P = 0.04). Thirty-two children accepted glucocorticoid treatment, while 33 (97%) children demonstrated clinical improvement within 1 week, 21 children (61.8%) achieved clinical recovery within 1 month. Eight children (23.5%) suffered a relapse, the median interval between the initial attack and recurrence was 13 (range: 3-36) months. We detected neurological sequelae in seven (20.6%) children, with visual dysfunction being the most common sequela (85.7%).

CONCLUSION

ADEM was the most common phenotype in both monophasic and relapsed paediatric MOGAD, followed by ON. Majority of pediatric MOGAD patients were highly responsive to glucocorticoid. Despite a benign prognosis in most patients, some patients endure neurological sequelae, mainly visual impairment. Patients with initial visual impairment should be carefully evaluated and administered individualized immunotherapy.

Clinical and neuroimaging findings in MOGAD-MRI and OCT

Myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) are rare in both children and adults, and have been recently suggested to be an autoimmune neuroinflammatory group of disorders that are different from aquaporin-4 autoantibody-associated neuromyelitis optica spectrum disorder and from classic multiple sclerosis. In-vivo imaging of the MOGAD patient central nervous system has shown some distinguishing features when evaluating magnetic resonance imaging of the brain, spinal cord and optic nerves, as well as retinal imaging using optical coherence tomography. In this review, we discuss key clinical and neuroimaging characteristics of paediatric and adult MOGAD. We describe how these imaging techniques may be used to study this group of disorders and discuss how image analysis methods have led to recent insights for consideration in future studies.

Evidence for and against subclinical disease activity and progressive disease in MOG antibody disease and neuromyelitis optica spectrum disorder

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and aquaporin-4 IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD) are generally considered to be relapsing disorders, without clinical progression or subclinical disease activity outside of clinical relapses, in contrast to multiple sclerosis (MS). With advances in the diagnosis and treatment of these conditions, prolonged periods of remission without relapses can be achieved, and the question of whether progressive disease courses can occur has re-emerged. In this review, we focus on studies exploring evidence for and against relapse-independent clinical progression and/or subclinical disease activity in patients with MOGAD and AQP4-IgG+ NMOSD.

Clinical and Imaging Features of Patients With Encephalitic Symptoms and Myelin Oligodendrocyte Glycoprotein Antibodies

Background

Myelin oligodendrocyte glycoprotein-antibody (MOG-ab)-associated disease (MOGAD) has highly heterogenous clinical and imaging presentations, in which encephalitis is an important phenotype. In recent years, some atypical presentations in MOG-ab-associated encephalitis (MOG-E) have been increasingly reported but have not yet been described well. The aim of the study was to describe the clinical and imaging features of patients with MOG-E in our center. Atypical phenotypes would be reported, which is expected to expand the spectrum of MOGAD.

Methods

We reviewed medical records of 59 patients with MOGAD diagnosed in our center and identified cases who had ever experienced encephalitic symptoms. Three hundred ten patients with autoimmune encephalitis (AE) were also reviewed, and cases with positive MOG-ab were identified. Besides, patients with chronically progressive encephalitis were identified from 13 MOG-E and 310 AE patients. We collected demographic, clinical, laboratory, radiological, and outcome data to explore clinical and imaging characteristics in MOG-E, especially in the atypical phenotype of chronically progressive encephalitis.

Results

We identified 13 patients (7 males, 6 females) with MOG-E. The median age at onset was 33 years (range 13~62 years). Most (9/13, 69.2%) of patients showed acute or subacute onset of encephalitic symptoms. Brain MRI abnormalities were observed in all patients. The most common lesion locations on MRI were cortical/subcortical (11/13, 84.6%), deep/periventricular white matter (10/13, 76.9%) and corpus callosum (4/13, 30.8%). Brain MRI patterns were categorized into four phenotypes. The most common pattern was cortical encephalitis with leptomeningeal enhancement/brain atrophy (10/13, 76.9%). Eight (8/13, 61.5%) patients had a good response to immunotherapy. Four (4/13, 30.8%) patients with chronically progressive course were identified from MOG-E cohort. They showed leukodystrophy-like pattern, multifocal hazy lesions, or cortical encephalitis on MRI. With immunotherapy, they only showed mild or no improvement. We also identified four (4/310, 1.3%) patients with chronically progressive course from AE cohort. They had better outcomes than counterparts in MOG-E.

Conclusions

This study demonstrates that encephalitic presentations in MOGAD had complex clinical patterns. Chronically progressive encephalitis may be a new phenotype of MOGAD. We recommend to test MOG-ab in subacute and chronic progressive dementia with leukodystrophy-like MRI lesions.

Multifocal visual evoked potential evaluation for diagnosis of acute optic neuritis and for prediction of visual outcome and ganglion cell layer thinning following optic neuritis

BACKGROUND

While damage to the optic nerve following optic neuritis (ON) is readily quantifiable, the evaluation of prognosis for visual function and neuroaxonal loss in the acute ON is challenging.

OBJECTIVE

The objective of this study is to investigate the value of multifocal visual evoked potential (mfVEP) in acute ON, diagnostically for acute ON and prognostically for visual outcome and subsequent ganglion cell/inner plexiform layer thickness (GCLIPLt).

METHODS

A prospective cohort study of mfVEP and full-field visual evoked potential (ffVEP) in acute, unilateral ON (onset < 31 days) was conducted. Comparisons with healthy controls (n = 30) and association analysis with follow-up optical coherence tomography (OCT) measurements (of the GCLIPLt) and visual function (Sloan low-contrast visual acuity (LCVA)) were conducted.

RESULTS

Seventy-nine ON patients were included (mean: 17 days from onset). Excluding measurements with conduction block, ffVEP (n = 54) and mfVEP (n = 44) showed sensitivities of 89% and 84% to a specificity of 97%. 65/79 patients were re-examined (mean: 200 days follow-up). mfVEP amplitude and latency inter-eye asymmetry in acute ON correlated with GCLIPLt (r = 0.587 and Spearman's ρ = 0.597, for both, p < 0.001). mfVEP amplitude correlated with LCVA inter-eye asymmetry at follow-up (r = 0.421, p < 0.001), mfVEP latency did not.

CONCLUSION

mfVEP may support the prognostic evaluation of acute ON patients and prove valuable in future neuroprotective and remyelinating trials. In acute ON, the increase in diagnostic value of mfVEP to ffVEP may be limited due to widespread conduction block.

[Epidemiology of neuromyelitis optica spectrum disorder]

Neuromyelitis optica spectrum disorder (NMOSD) is a group of rare and mostly severe autoimmune demyelinating central nervous system disorders which prevalence is 0.7-1 per 100.000 population and incidence is 0.037-0.73 per 100.000 person-years. NMOSD may present as a combination of uni- or bilateral optic neuritis, transverse myelitis or lesions of brain stem and other brain regions. The symptoms are mostly relapsing (up to 97.5%) and progressive. Occurrence of relapses is associated with seropositivity for aquaporin-4 (up to 80% of NMOSD patients) and bears a less favorable prognosis (mortality up to 32%). Women seropositive for aquaporin 4 constitute 90% of NMOSD patients. Compared to other demyelinating disorders, NMOSD is characterized by late onset (mean age is about 39 years) and association with other autoimmune disorders, including systemic lupus erythematosus, myasthenia gravis and Sjogren's syndrome. A genetic predisposition was found among Blacks and Asians, with HLA-DRB1*03:01 gene associated with higher risk of NMOSD in Asians. The course of the disease tends to be more severe in Blacks. There are clusters of an increased incidence of NMOSD in the Carribeans and in the Far East. Continued increase of prevalence and incidence of NMOSD worldwide compels continued epidemiological research in order to provide early diagnosis and treatment for this disorder.

Comparisons of clinical phenotype, radiological and laboratory features, and therapy of neuromyelitis optica spectrum disorder by regions: update and challenges

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) associated with autoantibody (ab) to aquaporin-4 (AQP4). There is obvious variation between regions and countries in the epidemiology, clinical features and management in NMOSD. Based on published population-based observation and cohort studies, the different clinical pattern of NMOSD has been seen in several geographical regions and some of these patients with NMOSD-like features do not fully meet the current diagnostic criteria, which is needed to consider the value of recently revised diagnostic criteria. At present, all treatments applied in NMOSD have made great progress, however, these treatments failed in AQP4 ab negative and refractory patients. Therefore, it is necessary to turn into an innovative idea and to open a new era of NMOSD treatment to develop novel and diverse targets and effective therapeutic drugs in NMOSD and to conduct the trails in large clinical samples and case-control studies to confirm their therapeutic effects on NMOSD in the future, which still remain a challenge.