A Rare Case of ADEM after Japanese Encephalitis

Acute disseminated encephalomyelitis (ADEM) is a monophasic demyelinating disease of central nervous system (CNS) which is most frequently associated with an antecedent infection (identified in ~ 50-77%). 5% of ADEM cases follow immunization. Post infectious autoimmune events associated with Japanese encephalitis (JE) have been limited to Guillian Barre Syndrome (GBS) and JE virus vaccine related ADEM. We hereby report a case of 18 year boy who presented to us with fever, urinary retention, bilateral diminution of vision and acute onset paraparesis. Japanese encephalitis was diagnosed by elevated IgM titres against JE virus in cerebrospinal fluid (CSF). ADEM was confirmed by MRI brain and spinal cord. Our patient also developed bilateral eye optic neuritis presenting clinically as sudden onset blurring of vision in both eye one day after admission and confirmed by visual evoked potential (VEP) study. His symptoms improved after giving high dose intravenous methylprednisolone.