The Clinical Features of FLAIR-Hyperintense Lesions in Anti-MOG Antibody Associated Cerebral Cortical Encephalitis with Seizures: Case Reports and Literature Review

Abstract

BackgroundThe presence of fluid attenuated inversion recovery (FLAIR)-hyperintense lesions in anti-myelin oligodendrocyte glycoprotein (MOG) antibody-associated cerebral cortical encephalitis with seizures (FLAMCES) was recently reported. However, the clinical characteristics and outcome of this rare clinico-radiographic syndrome remain unclear.MethodsThe present study reported two new cases. In addition, cases in the literature were systematically reviewed to investigate the clinical symptoms, magnetic resonance imaging (MRI) abnormalities, treatments and prognosis for this rare clinico-radiographic syndrome.ResultsA total of 21 cases were identified during a literature review, with a mean patient age at onset of 26.8 years. The primary clinicopathological characteristics included seizures (100%), headache (71.4%), fever (52.3%) and other cortical symptoms associated with the encephalitis location (61.9%). The common seizure types were focal to bilateral tonic-clonic seizures (28.6%) and unknown-onset tonic-clonic seizures (38.1%). The cortical abnormalities on MRI FLAIR imaging were commonly located in the frontal (58.8%), parietal (70.6%) and temporal (64.7%) lobes. In addition, pleocytosis in the cerebrospinal fluid was reported in the majority of the patients (95.2%). All patients received a treatment regimen of corticosteroids and 9 patients received anti-epileptic drugs. Clinical improvement was achieved in all patients; however, one-third of the patients reported relapse following recovery from cortical encephalitis.ConclusionsFLAMCES is a rare phenotype of MOG-associated disease. Thus, the wider recognition of this rare syndrome may enable timely diagnosis and the development of suitable treatment regimens.

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

“…We finally obtained 33 cases from 25 articles and combined with our two cases, a total of 35 cases were reviewed systematically ( Ogawa et al, 2017 ; Hamid et al, 2018 ; Ikeda et al, 2018 ; Budhram et al, 2019 , 2020 ; Haddad et al, 2019 ; Patterson et al, 2019 ; Fujimori et al, 2020b ; Hochmeister et al, 2020 ; Katsuse et al, 2020 ; Matoba et al, 2020 ; Otani et al, 2020 ; Russ et al, 2020 ; Takamatsu et al, 2020 ; Tao et al, 2020 ; Ahsan et al, 2021 ; Chang et al, 2021 ; Doig et al, 2021 ; Jain et al, 2021 ; Kim et al, 2021 ; Maniscalco et al, 2021 ; Nie et al, 2021 ; Stamenova et al, 2021 ; Tian et al, 2021 ; Wang et al, 2021 ; Table 1 ). The main demographic data, clinical characteristics, laboratory results, and imaging results are presented in Table 2 .…”

“…Since MOG antibody (MOG-Ab)-related cerebral cortical encephalitis (CCE) was first reported by Ogawa et al (2017) , many cases of this rare clinical phenotype have been reported globally, which may have been diagnosed with unexplained steroid-responsive encephalitis in the early stages of the disease ( Wang et al, 2021 ). CCE is a syndrome with an unclear clinical definition and is characterised by grey matter lesions on brain MRI, primarily involving the cerebral cortex and sulcus, but not the subcortical and deep white matter ( Krupp et al, 2013 ; Ogawa et al, 2017 ; Hamid et al, 2018 ).…”

Clinical Features and Imaging Findings of Myelin Oligodendrocyte Glycoprotein-IgG-Associated Disorder (MOGAD)

“…FLAMCES is a recently reported subtype of MOGAD that is mainly characterized by hyperintense lesions on MRI FLAIR sequences, cortical encephalitis, and seizures. Approximately 21 cases have now been reported ( Budhram et al, 2019 ; Mirian et al, 2021 ; Wang et al, 2021 ). According to Wang’s review, the age of onset was younger (26.8 years on average), with a larger proportion of males (76.2%).…”

“…All the patients received glucocorticoid therapy and showed recovery of symptoms and lesions. Some patients (9/21) were treated with antiepileptic drugs, and no unprovoked seizures were reported ( Wang et al, 2021 ). Because seizures are thought to be caused by encephalitis, long-term antiepileptic drugs are not recommended.…”

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

“…Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an inflammatory demyelinating disease of the central nervous system (CNS), and typically presents as optic neuritis, transverse myelitis, brainstem demyelination and acute disseminated encephalomyelitis (1). Recently, MOG antibody-related cerebral cortical encephalitis, a rare clinical phenotype of MOGAD, has been reported (2,3). Of note, atypical clinical manifestations for demyelinating diseases including fever, seizures, headaches, and cerebral cortical symptoms such as aphasia, mental disorder, and memory impairment, are common in MOG cortical encephalitis (1).…”