Clinical features and prognosis of the adult patients positive for both N-methyl-d-aspartate receptor (NMDAR) and myelin oligodendrocyte glycoprotein (MOG) antibodies

Yifang Ma^1*Binting Liu²Xiaojiao Ci²Jie Lu^2*

• ¹Department of Neuro-Psychiatric Institute, The Affiliated Brain Hospital of Nanjing Medical University, Nanjing, China
• ²Nanjing Brain Hospital, Nanjing, China

The coexistence of the MOG antibody (MOG-ab) and NMDAR antibody (NMDAR-ab), which is known as the MOG-ab and NMDAR-ab overlapping syndrome (MNOS), is the most common in overlapping syndromes of neural autoantibodies. The study aimed to analyze the clinical features and outcomes in adult patients suffering from MNOS and investigate the mechanisms of the disorder. The study included 23 adult patients of MNOS. Moreover, the clinical symptoms and prognosis of 23 MNOS patients were compared with those of 51 anti-NMDAR encephalitis (anti-NMDARE) patients and 30 MOG antibody-associated disorders (MOGAD) patients, respectively. The study cohort comprised 20 males (86.96%) and 3 females (13.04%), with a mean age of onset of 36.17±11.21 years. Prodromal infection was observed in 9 patients (39.13%). Sleep disorder was most common (69.57%), followed by psychiatric disorder and cognitive impairment (65.22%), consciousness disorder (60.87%), seizures (56.52%), speech disorder (39.13%), and headache (39.13%). Radiologically, 5 patients (21.74%) had damage to the cerebral cortex and basal ganglia. 4 patients (17.39%) had damage to the brainstem. All patients received first-line immunotherapy, and 16 (69.57%) of these patients received second-line treatment and long-term immunotherapy. Across 23 clinical attacks, the median modified Rankin Scale score (mRS) improved from 3 (interquartile range (IQR): 3,4) pre-treatment to 1 (IQR: 0,1) post-treatment. Relapses occurred in 6 patients (26.09%). In terms of gender, psychiatric disorder, and brainstem involvement, there were significant differences between the anti-NMDARE group and the MNOS group. Regarding visual impairment, limb weakness, deep white matter lesion, and QAlb, differences were observed between the MOGAD group and the MNOS group. When atypical clinical symptoms and imaging results appear, clinicians should consider the possibility of antibody overlap. During anti-NMDARE relapse, attention should be paid to whether anti-MOG antibodies are co-present.