Abstract
Acute disseminated encephalomyelitis (ADEM) is a monophasic autoimmune demyelinating disease of the central nervous system, which typically follows acute viral or bacterial infection or vaccination. We report a case of ADEM associated with hepatitis C virus (HCV) infection with positive serum and cerebrospinal fluid (CSF) anti-HCV antibody. After steroid treatment, neurologic symptoms were improved. Virus triggers autoimmunity or direct viral invasion plays a part in the genesis of ADEM. This is the first reported case of ADEM with anti-HCV antibody in the CSF.