Isolated seizures during the first episode of relapsing myelin oligodendrocyte glycoprotein antibody‐associated demyelination in children

Abstract

Myelin oligodendrocyte glycoprotein (MOG) antibodies have a strong association with acute disseminated encephalomyelitis (ADEM) in children, and bilateral and recurrent optic neuritis in children and adults. Recent reports suggest that seizures and encephalopathy may occur in children and adults with MOG antibody-associated disease. We describe the clinical, laboratory, and radiological course of four MOG antibody-positive children who first presented with isolated seizures without fulfilling clinical or radiological criteria for ADEM or other central nervous system demyelination syndromes, who months to years later developed more typical demyelination. This case series highlights a novel observation that isolated seizures in the absence of ADEM may be the index presentation for MOG antibody-associated disease, which should therefore be considered a form of autoimmune epilepsy. It would be reasonable to test for MOG antibodies in children with seizures accompanied by subtle inflammatory changes on magnetic resonance imaging or cerebrospinal fluid analyses, particularly if followed by demyelination, given the clinical and therapeutic implications of an expedited diagnosis in minimizing long-term disability. WHAT THIS PAPER ADDS: Isolated seizures in the absence of acute disseminated encephalomyelitis may be the index presentation for myelin oligodendrocyte glycoprotein antibody-associated demyelination.

The widening spectrum of myelin oligodendrocyte glycoprotein antibody‐associated disorders in children

“…It wraps around axons in the central nervous system to improve neuronal conductivity. MOG antibodies are associated with acquired demyelination of the central nervous system (CNS) . The spectrum of these disorders which includes optic neuritis, acute disseminated encephalomyelitis (ADEM), brainstem encephalitis, and transverse myelitis is evolving …”

“…Patients may have an isolated attack, multifocal attacks, or recurrent attacks. ADEM and other monophasic attacks are more common in children than adults . Clinically, presentations can look similar to aquaporin‐4 neuromyelitis optica, although pathologically they look different and recovery of function tends to be better in MOG antibody positive patients.…”

“…A proportion of patients with MOG are also left with significant disability . To date, seizures have been described with MOG antibody positivity in the setting of other neurological features . Radiologically there can be some overlap between ADEM, neuromyelitis optica, and multiple sclerosis, though neuromyelitis optica and MOG antibodies have never been reported together.…”

“…In 2018 an international panel of experts on demyelinating disorders met and established guidelines on when to suspect MOG antibody related disorders . In the recent case series by Ramanathan et al, the authors describe four MOG antibody positive paediatric cases who initially presented with focal seizures, without features of optic neuritis, brainstem encephalitis, transverse myelitis, or ADEM. Further, classic radiological and cerebrospinal fluid changes were absent in three of the cases, with only one child having cerebrospinal fluid inflammation and two children having non‐specific brain lesions at their original presentations.…”

“…The authors make the case that MOG antibody should be added to the increasing list of cell surface antibodies associated with autoimmune epilepsy. They recommend that children with first seizures with features of inflammation in their cerebrospinal fluid or on brain imaging should be considered for MOG antibody testing in order to institute early immunotherapy . Whether isolated seizures as a forme fruste of MOG antibody‐associated demyelination is a rare phenomenon remains to be determined, but the spectrum of MOG antibody disorders is widening.…”