Isolated involvement of substantia nigra in Japanese encephalitis.

A 16-year-old boy presented with febrile encephalopathy with meningeal signs, abnormal eye movements and extrapyramidal features. Clinical impression was meningo-encephalitis due to infective aetiology. He was diagnosed as a case of Japanese encephalitis. MRI brain revealed bilateral, symmetrical hyperintensities of substantia nigra. This neuro-imaging finding is very rarely reported in Japanese encephalitis.