In Children, N-Methyl-D-Aspartate Receptor Antibody Encephalitis Incidence Exceeds That of Japanese Encephalitis in Vietnam

Abstract

Background The recognition of autoimmune causes of encephalitis has led to epidemiological shifts in the worldwide characteristics. N-Methyl-D-Aspartate receptor antibody encephalitis leads to well-established complex neuropsychiatric manifestations. In low- and middle-income countries, including Vietnam, its relative incidence, especially in children, is unknown and most neurologists currently consider infectious encephalitis prior to autoimmune etiologies. Methods The study was prospectively conducted at Children’s Hospital 1 in Ho Chi Minh City between March 2020 and December 2022. Any child admitted to the Department of Infectious Diseases and Neurology fulfilling the case definition of encephalitis, was eligible to participate. Cerebrospinal fluid samples were collected alongside meta-clinical data for analysis. Results We recruited 164 children with a clinical diagnosis of encephalitis. Etiologies were determined as N-Methyl-D-Aspartate receptor antibody encephalitis in 23/164 cases (14.0%), Japanese Encephalitis Virus in 14/164 (8.5%) and Herpes Simplex Virus in 4/164 (2.4%). Clinical categorizations suggested idiopathic viral encephalitis in another 71 (43.3%), and autoimmune encephalitis of unknown origin in the remaining 52. Factors including demographics, specific clinical features, cerebrospinal fluid and electroencephalogram findings, and length of hospital stay were significantly different between N-Methyl-D-Aspartate receptor antibody encephalitis and Japanese encephalitis. Conclusions At a tertiary children’s hospital in Vietnam, the prevalence of N-Methyl-D-Aspartate receptor antibody encephalitis exceeds that of Japanese encephalitis, the most common infectious encephalitis cause in Southeast Asia. N-Methyl-D-Aspartate receptor antibody encephalitis is associated with long hospital stay and poor outcomes. These findings should change paediatric diagnostics, to earlier consider autoimmune treatments in this clinical setting.