Bilateral thalamic involvement in scrub typhus meningoencephalitis: a case report of an uncommon neuroimaging pattern mimicking Japanese encephalitis.

BACKGROUND

Scrub typhus is a major but under-recognised cause of acute febrile illness in Southeast Asia. Neurological involvement occurs in up to 20% of cases, but bilateral thalamic lesions, which are classically associated with Japanese encephalitis (JE), are rare in scrub typhus.

CASE PRESENTATION: A 45-year-old woman presented during the monsoon season with high-grade fever, altered mental status and generalised tonic-clonic seizure. MRI revealed bilateral symmetric thalamic T2/FLAIR hyperintensities with diffusion restriction, initially raising strong suspicion for JE. Serological testing showed positive scrub typhus IgM/IgG and negative JE IgM. Lumbar puncture was deferred due to raised intracranial pressure. She was managed with intravenous doxycycline, ceftriaxone, acyclovir (later discontinued), hypertonic saline, corticosteroids and supportive ICU care.

CONCLUSION

This case highlights a rare neuroimaging manifestation of scrub typhus that closely mimics JE. In endemic regions, scrub typhus should be considered in febrile neurological illness even in the absence of eschar or typical imaging findings.