[Clinical features of autoimmune encephalitis secondary to epidemic encephalitis B in 5 children].

OBJECTIVES: To study the clinical features of children with autoimmune encephalitis (AE) secondary to epidemic encephalitis B (EEB). METHODS: A retrospective analysis was performed on the medical data of five children with EEB with "bipolar course" who were treated in Children's Hospital Affiliated to Zhengzhou University from January 2020 to June 2022. RESULTS: Among the five children, there were three boys and two girls, with a median age of onset of 7 years (range 3 years 9 months to 12 years) and a median time of 32 (range 25-37) days from the onset of EEB to the appearance of AE symptoms. The main symptoms in the AE stage included dyskinesia (5/5), low-grade fever (4/5), mental and behavioral disorders (4/5), convulsion (2/5), severe disturbance of consciousness (2/5), and limb weakness (1/5). Compared with the results of cranial MRI in the acute phase of EEB, the lesions were enlarged in 3 children and unchanged in 2 children showed on cranial MRI in the AE stage. In the AE stage, four children were positive for anti-N-methyl-D-aspartate receptor antibody (one was also positive for anti-γ-aminobutyric acid type B receptor antibody), and one was negative for all AE antibodies. All five children in the AE stage responded to immunotherapy and were followed up for 3 months, among whom one almost recovered and four still had neurological dysfunction. CONCLUSIONS: EEB can induce AE, with anti-N-methyl-D-aspartate receptor encephalitis as the most common disease. The symptoms in the AE stage are similar to those of classical anti-N-methyl-D-aspartate receptor encephalitis. Immunotherapy is effective for children with AE secondary to EEB, and the prognosis might be related to neurological dysfunction in the acute phase of EEB.