[Clinical analysis of 71 cases of anti-N-methyl-D-aspartate receptor encephalitis in children]

Objective: To investigate the clinical features, treatment strategies and long term outcomes of children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Methods: The data of clinical features, auxiliary examinations, treatments and prognosis in children with anti-NMDAR encephalitis in Xiangya Hospital of Central South University from March 2014 to October 2017 were collected and retrospectively analyzed. A total of 71 patients were enrolled, including 33 males and 38 females. The youngest age of onset was 4 months old, and the age of onset was (9±4) years. The first-line immunotherapy treatment for anti-NMDAR encephalitis was short course corticosteroid (high-dose impulse therapy and oral maintenance therapy for 1 month in acute period) and (or) immunoglobulin. The clinical evaluation was performed 2 weeks after first-line immunotherapy treatment. The second-line immunotherapy treatment, including rituximab and (or) cyclophosphamide, would be started if the symptoms did not improve significantly and the modified Rankin scale (mRS) score ≥3. All patients were followed up and evaluated for prognosis. T-test, Mann-Whitney U, Chi square test and Fisher's exact probability method were used for comparison between good outcome group and poor outcome group, first-line immunotherapy group and first-line immunotherapy combined with second-line immunotherapy group. Results: The more common clinical manifestations were psychiatric symptoms (n=61, 86%), dyskinesia (n=55, 77%) and convulsions (n=51, 72%). Two cases (3%) had tumors. Electroencephalogram (EEG), cerebro-spinal fluid (CSF) and brain magnetic resonance imaging (MRI) studies were abnormal in 83% (59/71), 39% (27/69) and 38% (27/71) patients, respectively. For the treatment regimens, all the 71 patients underwent first-line immunotherapy, resulting in improvement within 14 days in 40 cases (56%), and 1 case (1%) died. The rest 30 cases (42%) received second-line immunotherapy. The patients were followed up for 5.0-41.8 months, with a median of 19.3 months. At the last follow-up, 49 cases (69%) recovered completely, 15 cases (21%) had mild disability, 6 cases (8%) had severe disability, 1 case (1%) died and 3 cases (4%) had relapse. There were significant differences between the groups with good prognosis and poor prognosis on admission to pediatric intensive care unit (PICU) and consciousness disorder (10/64 vs. 5/7, 39/64 vs. 7/7, P=0.047, 0.004). There were significant differences between first-line immunotherapy group and the first-line combined second-line immunotherapy group on admission to PICU, consciousness disorder, sleep disorder and first mRS score (12% (5/41) vs. 33% (10/30), 44% (18/41) vs. 93% (28/30), 56% (23/41) vs. 90% (27/30), 3 (1-5) vs. 4 (3-5), respectively; χ(2)=4.645, 18.555, 9.560, Z=5.184, P=0.031, <0.01, 0.002, <0.01, respectively). Conclusions: Anti-NMDAR encephalitis can occur in all ages of children. The most common clinical manifestations are psychotic symptoms, dyskinesia and convulsions. Paraneoplastic cases are less common in children. Immunotherapy is effective. The second-line immunotherapy should be given after the failure of first-line therapy (mRS score≥3).