Isolated involvement of substantia nigra in Japanese encephalitis

Area of Science:

• Neurology
• Infectious Diseases
• Radiology

Background:

• Japanese encephalitis is a significant cause of viral encephalitis in Asia.
• Encephalopathy with meningeal signs, abnormal eye movements, and extrapyramidal features can indicate severe neurological involvement.

Observation:

• A 16-year-old male presented with acute febrile encephalopathy, meningeal irritation, abnormal eye movements, and extrapyramidal symptoms.
• Initial clinical diagnosis suggested meningo-encephalitis of infectious origin.

Findings:

• The patient was diagnosed with Japanese encephalitis.
• Magnetic Resonance Imaging (MRI) of the brain revealed bilateral, symmetrical hyperintensities in the substantia nigra.
• These specific MRI findings are exceptionally uncommon in reported cases of Japanese encephalitis.

Implications:

• This case underscores the diverse and sometimes rare neuroimaging manifestations of Japanese encephalitis.
• The substantia nigra involvement suggests potential mechanisms of viral neurotoxicity affecting motor pathways.
• Further research into the pathobiology of JE may elucidate these rare imaging findings and their clinical significance.