Myelin Oligodendrocyte Glycoprotein Antibody Associated Cerebral Cortical Encephalitis: Case Reports and Review of Literature

Myelin oligodendrocyte glycoprotein antibody-associated disease presenting as unilateral cerebral cortical encephalitis: a case report

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune disorder with diverse clinical manifestations including myelitis, meningitis, encephalitis, and optic neuritis. MOGAD rarely presents with unilateral cerebral cortical encephalitis (CCE), rendering the diagnosis difficult in these cases. Furthermore, MOGAD is frequently accompanied by other autoimmune diseases such as thyroid disease or inflammatory bowel disease. Herein, we report a case of unilateral CCE with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. In addition, our patient presented with systemic symptoms as well as neurologic symptoms and was finally diagnosed with ulcerative colitis (UC). A 60-year-old female was admitted to the hospital with an acute onset of headache and fever. Neurological examination revealed left-sided homonymous hemianopsia with intermittent visual hallucinations as flickering red-circular spots in the left visual field. Brain magnetic resonance imaging showed focal hyperintensities and enhancement in the right temporo-parieto-occipital cortex. Electroencephalography indicated a focal seizure in the right occipital cortex. After the administration of an antiepileptic drug, the patient showed clinical and radiological improvements. She tested positive for serum anti-MOG antibodies and was diagnosed with anti-MOG-associated unilateral CCE. However, the gastrointestinal symptoms persisted, thus, a sigmoidoscopy was performed. The patient was diagnosed with comorbid UC. Steroids were administered to treat the UC and the gastrointestinal symptoms improved. To the best of our knowledge, this is the first case of MOGAD presenting as a unilateral CCE in Korea. This case highlights the clinical phenotypes of MOGAD and the need to assess comorbid autoimmune diseases in patients with MOGAD.

Less common phenotypes of myelin oligodendrocyte glycoprotein antibody-related diseases in children deserve more attention

BACKGROUND

To facilitate the identification of less common clinical phenotypes of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in children.

METHODS

We retrospectively reviewed medical records of 236 patients with MOGAD. The following phenotypes were considered to be typical for MOGAD: ADEM, ON, TM, and NMOSD. Less common onset clinical phenotypes were screened out; their clinical and magnetic resonance imaging (MRI), diagnosis, treatment, and prognosis were summarized and analyzed.

RESULTS

16 cases (6.8%) presented as cortical encephalitis, with convulsions, headache, and fever as the main symptoms. 15 cases were misdiagnosed in the early period. 13 cases (5.5%) showed the overlapping syndrome of MOGAD and anti-N-methyl-D aspartate receptor encephalitis (MNOS), with seizures (92.3%) being the most common clinical symptom. 11 cases (84.6%) showed relapses. The cerebral leukodystrophy-like phenotype was present in seven cases (3.0%), with a recurrence rate of 50%. Isolated seizures without any findings on MRI phenotype was present in three cases (1.3%), with the only clinical symptom being seizures of focal origin. Three cases (1.3%) of aseptic meningitis phenotype presented with prolonged fever.

CONCLUSION

40/236 (16.9%) of children with MOGAD had less common phenotypes. Less common clinical phenotypes of pediatric MOGAD are susceptible to misdiagnosis and deserve more attention.

IMPACT

This is the first comprehensive analysis and summary of all less commonl clinical phenotypes of MOGAD in children, while previous studies have only focused on a specific phenotype or case reports. We analyzed the characteristics of MOGAD in children and further revealed the reasons why these less common clinical phenotypes are prone to misdiagnosis and deserve more attention. Our research on treatment has shown that early detection of MOG antibodies and early treatment are of great significance for improving the prognosis of these patients.

FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures overlaying anti-N-methyl-D-aspartate receptor encephalitis: A case report

RATIONALE

FLAIR-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein (MOG)-associated encephalitis with seizures (FLAMES) is a rare clinical phenotype of anti-MOG; immunoglobulin G-associated disease is often misdiagnosed as viral encephalitis in the early stages. Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis caused by antibodies targeting the GluN1 subunit of the NMDAR. The coexistence of anti-NMDAR encephalitis and FLAMES is very rare.

PATIENT CONCERNS

A 20-year-old female patient initially presented with seizures accompanied by daytime sleepiness.

DIAGNOSES

Magnetic resonance imaging revealed FLAIR-hyperintense lesions in unilateral cerebral cortex. NMDAR antibodies was positive in the cerebrospinal fluid and MOG antibodies in the serum.

INTERVENTIONS

Steroid therapy was administrated.

OUTCOMES

The symptoms completely relieved. At 6-month follow-up, the patient's condition remained stable. Magnetic resonance imaging showed no abnormalities in the unilateral cerebral cortex.

CONCLUSION

When a patient with anti-NMDAR encephalitis or FLAMES is encountered in clinical practice, the coexistence of these diseases with double-positive anti-NMDAR and MOG antibodies should be considered and adopt appropriate evaluation and treatment.

Two case reports and a systematic review of the literature on adult cerebral cortical encephalitis with anti-myelin oligodendrocyte glycoprotein antibody

Background and purpose

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has gained recognition in recent years as an immune-mediated inflammatory demyelinating disease of the central nervous system. The clinical features and prognosis of MOGAD adult cerebral cortical encephalitis (adult CCE) have not been fully elucidated. This study aims to further characterize the clinical symptoms, magnetic resonance imaging (MRI) findings, and prognosis of CCE with anti-MOG antibody.

Methods

We present two adult cases of CCE with anti-MOG antibody and summarize the clinical symptoms, magnetic resonance imaging (MRI) findings, and prognosis of this phenotype as per a completed systematic review of the literature.

Results

We found a total of 39 cases of MOGAD adult CCE (36% females; average age of onset of 29 years). Among them, 85% had seizure, 82% had headache, 64% had cortical symptoms, 64% had fever, 54% had changes of consciousness, and 38% had ocular symptoms. All cases demonstrated cerebral cortical T2 fluid-attenuated inversion recovery (FLAIR) lesions on MRI. Of the 25 patients (with seizure or not) who had EEG reports, 76% of patients showed abnormal EEG. Cerebrospinal fluid (CSF) white blood cell count of 90% of patients and CSF total protein of 67% of patients were elevated. In 16 patients with available CSF cytology data, 11 (69%) had abnormal cytology findings with monocytic predominance. In the 15 cases for which MOG antibody IgG was tested in both serum and CSF, 14 (93%) demonstrated a higher positive MOG IgG titer in serum than CSF. The majority of patients were treated with immunosuppressive therapy (97% corticosteroids, 15% mycophenolate mofetil, 13% IVIg, 5% azathioprine, and 5% other). The majority of patients had a favorable prognosis after treatment, as exemplified by improved clinical symptoms and imaging. Two patients relapsed.

Conclusions

The clinical presentation and prognosis of adult CCE remain less understood in comparison to more common MOGAD phenotypes. It is important to consider MOGAD as an underlying etiology for adult CCE, as early detection and immunotherapy may improve outcomes.

Cerebral Cortical Encephalitis in Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

Cerebral cortical encephalitis (CCE) is a recently described myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) phenotype. In this observational retrospective study, we characterized 19 CCE patients (6.7% of our MOGAD cohort). Headache (n = 15, 79%), seizures (n = 13, 68%), and encephalopathy (n = 12, 63%) were frequent. Magnetic resonance imaging revealed unilateral (n = 12, 63%) or bilateral (n = 7, 37%) cortical T2 hyperintensity and leptomeningeal enhancement (n = 17, 89%). N-Methyl-D-aspartate receptor autoantibodies coexisted in 2 of 15 tested (13%). CCE pathology (n = 2) showed extensive subpial cortical demyelination (n = 2), microglial reactivity (n = 2), and inflammatory infiltrates (perivascular, n = 1; meningeal, n = 1). Most received high-dose steroids (n = 17, 89%), and all improved, but 3 had CCE relapses. This study highlights the CCE spectrum and provides insight into its pathogenesis. ANN NEUROL 2023;93:297-302.

Meningo-cortical manifestations of myelin oligodendrocyte glycoprotein antibody-associated disease: Review of a novel clinico-radiographic spectrum

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an inflammatory demyelinating disease that is distinct from multiple sclerosis. Initial manifestations of MOGAD that were reported in the literature included optic neuritis, myelitis, brainstem demyelination and encephalitis, with emphasis placed on acute disseminated encephalomyelitis (ADEM) as the primary encephalitic presentation. In 2017, however, Ogawa et al. described four patients with seizures, unilateral cortical hyperintensities on brain magnetic resonance imaging T2-fluid-attenuated inversion recovery sequences, and anti-MOG positivity, indicating a potentially novel form of encephalitis in MOGAD. In 2019, we systematically reviewed the literature to better characterize this unique syndrome, which we referred to as unilateral cortical FLAIR-hyperintense Lesions in Anti-MOG-associated Encephalitis with Seizures (FLAMES). Subsequently, anti-MOG positivity in patients with a variety of cortical and meningeal disease presentations has been reported, indicating a broader spectrum of meningo-cortical manifestations in MOGAD that we review herein.

Case report: Overlapping syndrome mimicking infectious meningoencephalitis in a patient with coexistent MOG, NMDAR, mGluR5 antibody positivity

A 38-year-old Chinese Han man presented with fever, headache and difficulty in language expression. The initial cerebrospinal fluid (CSF) analysis revealed lymphocytic-predominant pleocytosis with a normal glucose level, and magnetic resonance imaging (MRI) showed extensive cortical edema in left cerebral hemisphere. He received the antiviral treatment. However, one week later, he developed psychomotor agitation and seizures. Lumbar puncture was performed again and further testing for autoantibodies was conducted in both the CSF and serum. His CSF was positive for anti-myelin oligodendrocyte glycoprotein (MOG), anti-N-methyl-D-aspartate receptor (NMDAR) and anti-metabotropic glutamate receptor 5 (mGluR5) antibodies. He was diagnosed with overlapping syndrome of MOG antibody-related cerebral cortical encephalitis and anti-NMDAR, anti-mGluR5 autoimmune encephalitis. He received intravenous methylprednisolone and immunoglobulin, followed by oral prednisone and mycophenolate mofetil. His psychomotor agitation and seizures were relieved, and he gradually recovered his language expression ability. We reported for the first time a case that was positive for coexistent MOG, NMDAR, mGluR5 antibodies, which was initially misdiagnosed as infectious meningoencephalitis. This case widens the clinical spectrum of the overlapping syndrome recently reported.

Seizures and epilepsy in multiple sclerosis, aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Seizure is one of the manifestations of central nervous system (CNS) inflammatory demyelinating diseases, which mainly include multiple sclerosis (MS), aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). "Acute symptomatic seizures secondary to MS / AQP4-NMOSD / MOGAD" occur in the acute phase of the diseases, and are more frequent in MOGAD. In contrast, recurrent non-provoked seizures, mainly attributed to "autoimmune-associated epilepsy", occur in the non-acute phase of the diseases. Seizures in MS / AQP4-NMOSD / MOGAD mostly have a focal-onset. MS patients with concomitant systemic infections, an earlier onset and a higher disease activity are more likely to have seizures, whereas factors such as higher MS severity, the presence of status epilepticus and cortical damage indicate a greater risk of developing epilepsy. In MOGAD, cerebral cortical encephalitis, acute disseminated encephalomyelitis (ADEM)-like phenotypes (predominately ADEM and multiphasic disseminated encephalomyelitis) indicate a higher seizure risk. Multiple relapses with ADEM-like phenotypes predict epilepsy in pediatrics with MOGAD. Pathophysiologically, acute symptomatic seizures in MS are associated with neuronal hyperexcitability secondary to inflammation and demyelination. Chronic epilepsy in MS is largely due to gliosis, neuronal dysfunction and synaptic abnormalities. The mainstay of treatment for seizures secondary to MS / AQP4-NMOSD / MOGAD include immunotherapy along with antiseizure medications. This critical review discusses the most-updated evidence on epidemiology, clinical correlates, and inflammatory mechanisms underlying seizures and epilepsy in MS / AQP4-NMOSD / MOGAD. Treatment cautions including drug-drug interactions and the impact of treatments on the other are outlined. We also highlight pitfalls and challenges in managing such patients and future research perspectives to address unsolved questions.