Longstanding spastic paraparesis in a patient infected with hepatitis C virus and seropositive for aquaporin-4 antibody - Case report and review of the literature.

Nervous system involvement in Hepatitis C virus infection (HCV) has been associated to neuro-immunological deregulation, particularly in interferon-alpha treated patients. We present a case of optic and brainstem demyelinating disorder associated with aquaporin-4 (AQP4) antibodies. A 48 year-old woman, with previous diagnosis of non-treated hepatitis C, presented with a 10-year history of long-standing gait disturbance. Neurological examination disclosed a grade 4 spastic paraparesis, lower limb hyperreflexia, right positive Hoffmann sign, bilateral Babinski sign and spastic gait only possible with bilateral support. Spinal cord magnetic resonance imaging (MRI) was normal. Brain MRI showed an asymmetric, bilateral pontine and left mesencephalic hypersignal in T2 and FLAIR, with no gadolinium enhancement. Visual evoked potential revealed bilateral pre-chiasmatic conduction delay. Blood tests showed a positive anti-HCV antibody and a positive AQP4 antibody. Cerebrospinal fluid (CSF) analysis was normal, with no oligoclonal bands. The patient started intravenous (IV) methylprednisolone followed by oral prednisolone; simultaneously, interferon-alpha and ribavirin. There was a slight clinical improvement within the first weeks. There are 7 cases describing association between HCV infection and central nervous system (CNS) demyelination with positive AQP4 antibody, 4 patients under interferon-α. AQP4 antibodies should be tested in patients infected with HCV and CNS demyelination.