Clinical characteristics and treatment of patients with overlapping MOG and anti-NMDAR encephalitis

This study was designed to analyse the clinical manifestations, cerebrospinal fluid (CSF), imaging features, and treatment of patients who were CSF was positive for NMDAR antibodies (NMDAR-ab) and seropositive for MOG antibodies (MOG-ab). The clinical manifestations of thirteen patients with overlapping antibodies and presenting signs and symptoms of general encephalitis, such as fever and headache, impaired consciousness, mental and behavioural disturbances, and seizures, at the initial onset of disease were reviewed. Cranial MRI suggested that the most frequently involved areas were cortical and subcortical, and meningeal enhancement was observed in a few patients. Intravenous methylprednisolone (IVMP) and intravenous immunoglobulin (IVIG) are the mainstays of treatment in the acute phase. The median mRS score was 2 (1, 2.5) before treatment and 1 (0.5, 1) after treatment. Compared with the MOGAD group, the overlapping antibodies group had a greater proportion of adult patients who were admitted to the intensive care unit (ICU), experienced common mental and behavioural disturbances, had cortex or subcortical involvement on cranial MRI, and had less enhancement on gadolinium-enhanced scans (P < 0.05). Compared with the anti-NMDAR encephalitis group, the overlapping antibodies group had lower incidences of mental and behavioural abnormalities and seizures, and the brachium pontis was more prone to abnormal signals on cranial MRI (P < 0.05). Kaplan-Meier survival analysis revealed that during the 6–48 month follow-up period, there was no statistically significant difference in the recurrence rate between the overlapping antibodies group and the MOGAD group or the anti-NMDAR encephalitis group (P > 0.05).