Life-Threatening MOG Antibody-Associated Hemorrhagic ADEM With Elevated CSF IL-6.

Acute disseminated encephalomyelitis (ADEM) is one characteristic manifestation of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). A previously healthy man presented with retro-orbital headache and urinary retention 14 days after Tdap vaccination. Brain and spine MRI suggested a CNS demyelinating process. Despite treatment with IV steroids, he deteriorated, manifesting hemiparesis and later impaired consciousness, requiring intubation. A repeat brain MRI demonstrated new bilateral supratentorial lesions associated with venous sinus thrombosis, hemorrhage, and midline shift. Anti-MOG antibody was present at a high titer. CSF IL-6 protein was >2,000 times above the upper limits of normal. He improved after plasma exchange, then began monthly treatment alone with anti-IL-6 receptor antibody, tocilizumab, and has remained stable. This case highlights how adult-onset MOGAD, like childhood ADEM, can rapidly become life-threatening. The markedly elevated CSF IL-6 observed here supports consideration for evaluating CSF cytokines more broadly in patients with acute MOGAD.

Cerebrospinal fluid eosinophils in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Eosinophils in cerebrospinal fluid (CSF) are an uncommon finding most often associated with parasitic infections, but have also been described in some neuroinflammatory disorders. Eosinophilic infiltration is not thought to be a typical feature of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). We aim to describe the rate of CSF eosinophil positivity in a cohort of pediatric MOGAD patients. METHODS: Single-center retrospective chart review of pediatric MOGAD patients. Clinical and laboratory data was collected from the electronic medical record and analyzed. RESULTS: Of 46 pediatric patients with positive serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG) identified, 38 patients fulfilling internationally proposed MOGAD diagnostic criteria were included for analysis. 6 patients with MOGAD were excluded as no CSF data was available, and 2 patients with positive MOG-IgG but diagnosis more consistent with MS were excluded. Median age was 7.3 years, and 19/38 (50 %) were female. Acute disseminated encephalomyelitis (ADEM) was the most common presenting phenotype (23/38, 61 %), and other phenotypes included optic neuritis (10/38, 26 %), transverse myelitis (3/38, 8 %), and neuromyelitis optica spectrum disorder (NMOSD) (2/38, 5 %). 12 of 36 (33 %) patients with all lumbar puncture (LP) data available had CSF eosinophils present, with eosinophil mean of 3 % and range from 1 % to 18 % of CSF while blood cells. CONCLUSION: CSF eosinophils were present in one third of pediatric MOGAD patients, which is a higher rate than previously reported in either MOGAD or aquaporin-4 antibody positive NMOSD cohorts. Understanding the CSF composition of pediatric MOGAD patients helps to facilitate more prompt diagnosis and treatment and may shed light onto underlying pathologic mechanisms of disease with the goal to inform future therapeutic targets.

Central nervous system immune-related disorders after SARS-CoV-2 vaccination: a multicenter study.

Background: COVID-19 vaccines have been approved due to their excellent safety and efficacy data and their use has also permitted to reduce neurological complications of SARS-CoV-2. However, clinical trials were underpowered to detect rare adverse events. Herein, the aim was to characterize the clinical spectrum and immunological features of central nervous system (CNS) immune-related events following SARS-CoV-2 vaccination. Methods: Multicenter, retrospective, cohort study (December 1, 2020-April 30, 2022). Inclusion criteria were (1) de novo CNS disorders developing after SARS-CoV-2 vaccination (probable causal relationship as per 2021 Butler criteria) (2); evidence for an immune-mediated etiology, as per (i) 2016 Graus criteria for autoimmune encephalitis (AE); (ii) 2015 Wingerchuk criteria for neuromyelitis optica spectrum disorders; (iii) criteria for myelitis. Results: Nineteen patients were included from 7 tertiary referral hospitals across Italy and France (one of them being a national referral center for AE), over almost 1 year and half of vaccination campaign. Vaccines administered were mRNA-based (63%) and adenovirus-vectored (37%). The median time between vaccination and symptoms onset was 14 days (range: 2-41 days). CSF was inflammatory in 74%; autoantibodies were detected in 5%. CSF cytokine analysis (n=3) revealed increased CXCL-10 (IP-10), suggesting robust T-cell activation. The patients had AE (58%), myelitis (21%), acute disseminated encephalomyelitis (ADEM) (16%), and brainstem encephalitis (5%). All patients but 2 received immunomodulatory treatment. At last follow-up (median 130 days; range: 32-540), only one patient (5%) had a mRS>2. Conclusion: CNS adverse events of COVID-19 vaccination appear to be very rare even at reference centers and consist mostly of antibody-negative AE, myelitis, and ADEM developing approximately 2 weeks after vaccination. Most patients improve following immunomodulatory treatment.

Acute disseminated encephalomyelitis and transverse myelitis following COVID-19 vaccination - A self-controlled case series analysis.

Acute Disseminated Encephalomyelitis (ADEM) and Transverse Myelitis (TM) are within the group of immune mediated disorders of acquired demyelinating syndromes. Both have been described in temporal association following various vaccinations in case reports and case series and have been evaluated in observational studies. A recent analysis conducted by The Global Vaccine Data Network (GVDN) observed an excess of ADEM and TM cases following the adenoviral vectored ChAdOx1 nCoV-19 (AZD1222) and mRNA-1273 vaccines, compared with historically expected background rates from prior to the pandemic. Further epidemiologic studies were recommended to explore these potential associations. We utilized an Australian vaccine datalink, Vaccine Safety Health-Link (VSHL), to perform a self-controlled case series analysis for this purpose. VSHL was selected for this analysis as while VSHL data are utilised for GVDN association studies, they were not included in the GVDN observed expected analyses. The VSHL dataset contains vaccination records sourced from the Australian Immunisation Register, and hospital admission records from the Victorian Admitted Episodes Dataset for 6.7 million people. These datasets were used to determine the relative incidence (RI) of G040 (ADEM) and G373 (TM) ICD-10-AM coded admissions in the 42-day risk window following COVID-19 vaccinations as compared to control periods either side of the risk window. We observed associations between ChAdOx1 adenovirus vector COVID-19 vaccination and ADEM (all dose RI: 3.74 [95 %CI 1.02,13.70]) and TM (dose 1 RI: 2.49 [95 %CI: 1.07,5.79]) incident admissions. No associations were observed between mRNA COVID-19 vaccines and ADEM or TM. These findings translate to an extremely small absolute risk of ADEM (0.78 per million doses) and TM (1.82 per million doses) following vaccination; any potential risk of ADEM or TM should be weighed against the well-established protective benefits of vaccination against COVID-19 disease and its complications. This study demonstrates the value of the GVDN collaboration leveraging large population sizes to examine important vaccine safety questions regarding rare outcomes, as well as the value of linked population level datasets, such as VSHL, to rapidly explore associations that are identified.

Visual outcome measures in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) comprises various age-dependent clinical phenotypes and may be monophasic, multiphasic, or chronic. Optic neuritis (ON) is a common manifestation and frequently appears in combination with other MOGAD phenotypes, particularly in young children. Despite permanent structural damage to the retinal nerve fiber layer (RNFL), children often experience complete visual recovery. AIMS: To analyze the progression and impact of MOGAD on the visual system of pediatric patients independently of the history of ON. METHODS: This retrospective study included children who met specific criteria: myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG) seropositivity, acute presentation of MOGAD, and written general consent. Main outcome measures were global peripapillary retinal nerve fiber layer (pRNFL) thickness, and near and distance visual acuity, analyzed using descriptive statistics. RESULTS: We identified 10 patients with median age of 7.7 years at first event: 7 patients manifested with acute disseminated encephalomyelitis (ADEM) (with ON 5/7, ADEM only 1/7, with transverse myelitis (TM) 1/7), 2 with isolated ON, and 1 patient with neuromyelitis optica spectrum disorder (NMOSD)-like phenotype with ON. Among ON patients, 5/8 were affected bilaterally, with 3 initially diagnosed with unilateral ON but experiencing subsequent involvement of the fellow eye. None of the patients without previous ON showed a deterioration of visual acuity and, if evaluated, a reduction of the pRNFL. CONCLUSION: Most pediatric MOGAD-ON patients in our cohort presented with acute vison loss and optic disc edema. All patients achieved complete visual recovery, independent of number of relapses or initial visual loss. The pRNFL thickness decreased for several months and stabilized at reduced levels after 12 months in the absence of further relapses. MOGAD may not have subclinical/'silent' effects on the visual system, as visual acuity and pRNFL were not affected in patients without ON.

The role of plasmapheresis in severe acute disseminated encephalomyelitis with clinical findings of transverse myelitis.

INTRODUCTION: Acute disseminated encephalomyelitis is a rare acute demyelinating disease of the central nervous system (CNS). The pathogenesis remains unclear but is suspected to be autoimmune. High doses of methylprednisolone (HDMP) are currently considered standard of treatment. Plasmapheresis (PE) is typically given in steroid refractory cases. There is currently limited evidence supporting its use in ADEM. MATERIALS AND METHODS: We report a 16-year-old girl with ADEM who improved rapidly after initiating PE. RESULTS: The patient presented with acute onset of multifocal CNS symptoms, including encephalopathy, requiring intensive care unit management. Despite HDMP administration, her clinical condition continued to deteriorate. PE was therefore initiated on the same day as HDMP. Her clinical condition improved significantly following the first session. She was extubated and discharged from the intensive care unit the following day. CONCLUSION: HDMP combined with PE may be an effective first-line treatment in patients with fulminant ADEM.

Influenza B-induced longitudinally extensive transverse myelitis and bithalamic acute disseminated encephalomyelitis.

In the COVID-era, other viral pathogens, like influenza B, gain less attention in scientific reporting. However, influenza still is endemic, and rarely affects central nervous system (CNS). Here, we report the case of a 35-year-old male who presented with fever since 1 week, and developed acute ascending flaccid paralysis and urinary retention. The clinical presentation of paraparesis in combination with the inflammation proven by the lumbar puncture, and the MRI full spine, fulfilled the diagnostic criteria of longitudinally extensive transverse myelitis (LETM). In this case, it is most likely based on a post-viral Influenza type B. Additionally, the brain MRI showed a necrotizing encephalopathy bilaterally in the thalamus. Both locations of inflammatory disease were part of one auto-immune-mediated, monophasic CNS disorder: influenza-induced ADEM which is very unique, fortunately with favorable outcome.

Encefalomielite aguda disseminada com provável etiologia de Bartonella henselae / Acute disseminated encephalomyelitis with probable Bartonella henselae etiology

RESUMO A encefalomielite aguda disseminada é uma doença rara, aguda, inflamatória e desmielinizante do sistema nervoso central, presumivelmente associada, em mais de três quartos dos casos, a infecções (virais, bacterianas ou inespecíficas) e imunizações ou sem qualquer antecedente indentificável. Habitualmente, apresenta um curso monofásico com início de sintomas inespecíficos na fase prodrómica, podendo evoluir com alterações neurológicas multifocais e até à perda total da acuidade visual. Descrevemos o caso de um menino de 9 anos com quadro inicial de edema de papila causado por encefalomielite aguda disseminada devido a Bartonella henselae. Apesar da gravidade da doença, o diagnóstico e o tratamento precoce proporcionaram bons desfechos.

ABSTRACT Acute disseminated encephalomyelitis is a rare, acute, inflammatory, and demyelinating disease of the central nervous system. Presumably associated in more than three quarters of cases by infections (viral, bacterial, or nonspecific) and immunizations or without any identifiable antecedent. It usually presents a monophasic course with onset of nonspecific symptoms in the prodromal phase and may evolve with multifocal neurological changes and even visual acuity loss. We describe a case of a 9-year-old boy with an initial picture of papillary edema caused by acute disseminated encephalomyelitis due to Bartonella henselae. Despite the severity of the disease, early diagnosis and treatment provided good outcomes.

[Catatonia as an initial presentation of acute disseminated encephalomyelitis]. / Katatonie als initiële uiting van acute gedissemineerde encefalomyelitis.

We describe a case of a 36-year-old woman with no psychiatric or somatic history who was presented to the emergency department with a profound change in mental status, more precisely a catatonic status and auditory hallucinations. Due to the unclear aetiology and suspicion of underlying psychiatric problems, the patient was admitted to the psychiatric ward. After discharge against medical advice, readmission was necessary due to deterioration and sudden onset of myoclonus. On further examination, acute disseminated encephalomyelitis (ADEM) was diagnosed. This case illustrates that ADEM can present itself as an initial psychiatric problem and emphasizes the importance of extensive medical clearance at presentation and continued attention for possible somatic origin, even when the initial clearance turns out to be negative.

Intravenous immunoglobulin treatment for acute attacks in myelin oligodendrocyte glycoprotein antibody disease.

BACKGROUND: The potential therapeutic benefit of intravenous immunoglobulins (IVIGs) for acute attacks of myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is unknown. OBJECTIVE: The objective was to describe the outcomes of IVIG treatment for acute MOGAD attacks. METHODS: A retrospective observational study involving seven tertiary neuroimmunology centers. Data collection included patients' demographics, Expanded Disability Status Scale (EDSS), and visual acuity (VA) before the attack, at the nadir of the attack before IVIG treatment, and at follow-up visits ⩾3 months after treatment. RESULTS: Thirty-nine patients were included, of which 21 (53.8%) were female. The median age was 23 years (range 5-74 years), and the median disease duration was 4 months (range 0-93 months). The most common type of attack treated with IVIG was isolated optic neuritis (ON) (unilateral n = 14, bilateral n = 5, associated with transverse myelitis (TM), n = 1), followed by acute disseminated encephalomyelitis (ADEM) (n = 8), multifocal (n = 7), TM (n = 3), brainstem (n = 1), and other encephalitis (n = 1). A significant improvement in both the EDSS and VA measures was observed at follow-up compared to the time of IVIG treatment initiation (p < 0.0001 for both outcome measures). CONCLUSION: IVIG may be an effective treatment option for acute MOGAD attacks. Further prospective studies are warranted to validate our results.

[A case of anti-myelin oligodendrocyte glycoprotein antibody-positive multiphasic disseminated encephalomyelitis showing significant recovery after immunoadsorption plasmapheresis].

The patient is an 18-year-old female. She had a history of acute disseminated encephalomyelitis at the age of 6 and 7. She visited our hospital due to acute disturbance of consciousness, quadriplegia, and numbness of left upper and lower extremities. Brain MRI showed multiple DWI/FLAIR high-signal lesions in the bilateral cerebral hemispheres, cerebellum, and brainstem. Qualitative test indicated that serum anti-MOG antibodies was positive, and she was diagnosed with anti-MOG antibody-positive polyphasic disseminated encephalomyelitis. Intravenous mPSL pulse therapy was performed twice, but the symptoms worsened. As a second line treatment, plasma exchange was started. However, she developed transfusion related acute lung injury. Alternatively, she was treated with immunoadsorption plasmapheresis. Her symptoms were significantly improved. This case seems to be valuable because there are few reports showing effectiveness of immunoadsorption therapy on anti-MOG antibody-related diseases, especially for polyphasic disseminated encephalomyelitis.

Acute encephalomyelitis in a 52-year-old male post messenger ribonucleic acid severe acute respiratory syndrome coronavirus 2 vaccination: a case report.

BACKGROUND: Acute disseminated encephalomyelitis is a well-known, but rare, side effect of some vaccines, or symptom following a febrile illness. CASE: A 69-year-old, otherwise healthy Hispanic male presented with acute fever, confusion, and later progressive weakness after receiving the first dose of the mRNA-1273 (Moderna) severe acute respiratory syndrome coronavirus 2 vaccine. Considering the progressive deterioration of the patient, despite being on multiple immunosuppressive agents, a brain biopsy was obtained, which revealed nonspecific meningoencephalitis. CONCLUSION: In this case, we highlight the need for a regulatory framework to assist clinicians and patients with coverage of treatment for acute disseminated encephalomyelitis. The use of intravenous immunoglobulin in conjunction with glucocorticoids seems to be an effective treatment option.

Neurological sequelae of vaccines.

IMPORTANCE: Vaccines are a safe and efficacious way to prevent a variety of infectious diseases. Over the course of their existence, vaccines have prevented immeasurable morbidity and mortality in humans. Typical symptoms of systemic immune activation are common after vaccines and may include local soreness, myalgias, nausea, and malaise. In the vast majority of cases, the severity of the infectious disease outweighs the risk of mild adverse reactions to vaccines. Rarely, vaccines may be associated with neurological sequela that ranges in severity from headache to transverse myelitis, acute disseminated encephalomyelitis, and Guillain-Barre syndrome (GBS). Often, a causal link cannot be confirmed, and it remains unclear if disease onset is directly related to a recent vaccination. OBSERVATIONS: This review serves to summarize reported neurologic sequelae of commonly used vaccines. It will also serve to discuss potential pathogenesis. It is important to note that many adverse events or reactions to vaccines are self-reported into databases, and causal proof cannot be obtained. CONCLUSIONS AND RELEVANCE: Recognition of reported adverse effects of vaccines plays an important role in public health and education. Early identification of these symptoms can allow for rapid diagnosis and potential treatment. Vaccines are a safe option for prevention of infectious diseases.

Spinal cord involvement in COVID-19: A review.

Context: Recent literature points towards myelitis, like encephalitis, as a common central nervous system complication of COVID-19. This review elaborates on disorders of the spinal cord caused by the SARS-CoV-2 virus.Objectives: To review the published data about SARS-CoV-2-associated spinal cord disorders and assess their clinical, neuroimaging, treatment, and prognostic aspects.Methods: The PubMed and Google Scholar databases were searched for published cases using the search items "COVID-19 OR SARS-CoV-2 AND myelitis", "COVID-19 OR SARS-CoV-2 AND myelopathy", and "COVID-19 OR SARS-CoV-2 AND spinal cord".Results: Thirty-three isolated cases were included in the present review, of which 14 were aged 60 years and above (range: 3-70 years). Eighteen patients had lung abnormalities on chest imaging. Eight patients had developed either an areflexic paraparesis or quadriparesis. In 17 patients, neuroimaging demonstrated longitudinally extensive transverse myelitis, while 3 cases showed neuroimaging changes in the spinal cord as a part of acute disseminated encephalomyelitis syndrome. Cerebrospinal fluid (CSF) examinations revealed inflammatory changes in 18 patients. However, the SARS-CoV-2 virus in the CSF was discovered in 2 patients. In 2 patients, anti-SARS-CoV-2 antibodies were demonstrated in the CSF. Following treatment, 13 patients were able to walk.Conclusions: A variety of COVID-19-related spinal cord manifestations, such as acute transverse myelitis, acute necrotizing myelitis, SARS-CoV-2 myelitis, acute disseminated encephalomyelitis, neuromyelitis optica spectrum disorder, hypoxic myelopathy, MOG antibody-associated myelitis, spinal cord infarction, and spinal epidural abscess, have been reported. The possible mechanisms of this involvement being direct invasion, cytokine storm, coagulopathy, and an autoimmune response. However, response to treatment has been generally unsatisfactory, with many patients having residual weakness necessitating long-term rehabilitation.

Levamisole-associated multifocal inflammatory encephalopathy: clinical and MRI characteristics, and diagnostic algorithm.

Levamisole-associated multifocal inflammatory encephalopathy (LAMIE) is a devastating adverse effect of levamisole (LEV) treatment. In Russia, people often use LEV without a doctor's prescription for anthelmintic prophylaxis. LAMIE often misdiagnosed as the first episode of MS or acute disseminated encephalomyelitis (ADEM). The aim of our study was to describe clinical, laboratory and morphological characteristics of LAMIE, magnetic resonance imaging (MRI) patterns and create an algorithm for the differential diagnosis. This study was a prospective observational study with retrospective analysis of cases. It was performed at two hospitals with ambulatory service for MS. We included 43 patients with LAMIE with follow-up was from 1 year to 5 years. Age was 19-68 y.o. with female predominance. The most typical manifestations of LAMIE were cerebellar, pyramidal and cognitive symptoms, and majority of patients had biphasic course of the disease. Three main types of MRI patterns were described: ADEM-like, MS-like, atypical demyelination. About 40% of patients had CSF specific oligoclonal bands synthesis, but only 20 % of them converted to MS during the period from 1 month until 2 years. The CSF albumin levels and immunoglobulin G index were elevated in LAMIE patients compared to reference values. We described results of brain biopsy in two cases. Therefore LAMIE should be considered in patients with demyelinating or inflammatory conditions with biphasic onset of the disease and variable MRI presentation.

Eight-and-a-half syndrome as manifestation of acute disseminated adenovirus encephalomyelitis.

Acute disseminated encephalomyelitis is an immune mediated inflammatory-demyelinizing disease that usually manifests after infection or vaccination in school-age children. It typically presents a prodromal phase with flu-like symptoms, followed by a phase with varied clinical symptoms, neuro-ophthalmological alterations such as ophthalmoplegia or optic neuritis may occur. The differential diagnosis includes tumor, vascular, infectious, inflammatory and demyelinating diseases. Diagnosis is based on the clinical history and the characteristics of brain magnetic resonance imaging, the gold standard test. The study of the cerebrospinal fluid can help to guide the clinical picture. The prognosis is favorable, with an excellent response to corticosteroids and immunoglobulins, with minimal long-term sequelae in most cases. We report the case of an 8-year-old male with acute demyelinating disease due to adenovirus whose manifestation was an eight-and-a-half syndrome.

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.

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.