[Clinical observation on the overlapping syndrome of myelin oligodendrocyte glycoprotein antibody and anti-N-methyl-D aspartate receptor in children].

Objective: To investigate the clinical features, imaging findings and prognosis of children with overlapping syndrome of myelin oligodendrocyte glycoprotein (MOG) antibody disease and anti-N-methyl-D aspartate receptor (NMDAR) encephalitis (MNOS). Methods: The clinical manifestations, immunological antibodies in blood and cerebrospinal fluid, cranial image, treatment and follow-up of 11 patients diagnosed as MNOS in the Department of Neurology, Beijing Children's Hospital from January 2011 to April 2019 were analyzed retrospectively. Results: A total of 11 patients, including 4 males and 7 females were analyzed, the age of onset was (10.4±2.3) years. A total of 29 episodes occurred in 11 children. At the last follow-up, 8 cases showed relapsed remission course, the interval of recurrence was 3 to 60 months. The onset symptoms of 11 patients included convulsions (10 cases), lethargy (6 cases), psychosis (6 cases). Among 29 episodes, the common symptoms were convulsions (16 episodes), psychosis (13 episodes),and lethargy (10 episodes). According to the diagnostic criteria of anti-NMDAR encephalitis and MOG-antibody disease, 29 episodes were divided into three phenotypes, including anti-NMDAR encephalitis(4 episodes), MOG-antibody diseases (10 episodes) and overlapping types (15 episodes).Twenty-seven times of acute stage cranial magnetic resonance imaging (MRI) were available, common lesions included cortical focus (22 times), subcortical white matter (7 times), brainstem (9 times). All patients were sensitive to first-line immunotherapy. Eight patients had recurrence during glucocorticoid reduction, 6 of them were treated with additional second-line immunosuppressive therapy, including cyclophosphamide (1 case) and mycophenolate mofetil (5 cases). The follow-up time of patients were 5-99 months. At the last follow-up, all patients were in remission, the pediatric cerebral performance category (PCPC) score was 1 (10 cases) and 2 (1 cases). Conclusions: MNOS mainly affects older children. In the period of acute episodes, convulsions and psychosis are common. The cranial MRI showed extensive brain involvement and mainly in the cortex. The recurrence rates of MNOS are relatively high, patients are sensitive to first-line immunotherapy. No significant neurological dysfunction was left in the remission stage.