Acute symptomatic seizures secondary to myelin oligodendrocyte glycoprotein antibody-associated disease

Objective: To report the clinical presentations and outcomes of patients with seizure and myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD). Methods: We retrospectively reviewed the electronic medical records for clinical and paraclinical features among patients with seizures and MOG-IgG (immunoglobulin G) seropositivity. Results: We identified 213 patients with MOG-IgG seropositivity who fulfilled criteria for MOGAD. Seizures attributed to central nervous system (CNS) autoimmunity were observed in 10% of patients (n = 23: 19 children, 4 adults). The majority (n = 19, 83%) had pediatric disease onset. Focal motor seizures were the most common seizure semiology (16/23; 70%). Focal to bilateral tonic-clonic seizures were present in 12 patients (53%), and 3 patients (13%) developed status epilepticus. All patients had features of encephalitis at onset of seizures. Cerebral cortical encephalitis (CCE) was the most common radiological finding (10 unilateral and 5 bilateral cases). Eight of 23 patients (35%) had only CCE, six of 23 patients (26%) had only acute disseminated encephalomyelitis (ADEM), and seven of 23 patients (30%) had features of both. Fifteen patients (65%) had leptomeningeal enhancement. Three patients (13%) had coexistence of N-methyl-d-aspartate receptor (NMDAR) IgG. Only 3 of 23 patients (13%) developed drug- resistant epilepsy. Although the majority had MOGAD relapses (14/23, 60%) had only 5 of 23 patients had recurrence of episodes of encephalitis with associated seizures. Twenty-one of 23 patients (91%) had seizure freedom at last follow-up. Significance: MOG-IgG evaluation should be considered in patients who present with encephalitis and focal motor and/or focal to bilateral tonic-clonic seizures, especially pediatric patients with magnetic resonance imaging (MRI) brain findings consistent with CCE, ADEM, or other MOGAD presentations. The majority of these seizures are self-limited and do not require maintenance/chronic antiseizure medications. Although seizure recurrence is uncommon, many patients have MOGAD relapses in the form of encephalitis and optic neuritis.