Teaching NeuroImages: Japanese encephalitis

Abstract

A 20-year-old woman presented with 3 days' history of fever and deteriorating consciousness. Physical examination showed positive Kerning sign. Brain MRI revealed hyperintensity involving bilateral thalami and substantia nigra (figure). Although CSF tests for white blood cells, protein, glucose, chlorine, and TORCH antibodies were normal, Japanese encephalitis (JE) virus immunoglobulin M antibody was positive. Therefore, a diagnosis of JE was made. The patient recovered from coma, and brain lesions were disappearing after 3 months supportive care (figure). As a common human viral encephalitis in the world, JE is usually very severe with high case-fatality rate.1 Symmetric thalami and substantia nigra involvement are characteristic in JE.2