[A case of brainstem encephalitis following multiple cranial neuropathy in a hepatocellular carcinoma patient--association with cytomegalovirus and varicella-zoster virus infection].

A 72-year-old male with liver cirrhosis and hepatocellular carcinoma experienced general fatigue. Four days later he was admitted to our hospital because of dizziness, dysbasia and left facial palsy (day 1). On day 6, a neurological examination revealed left trigeminal neuralgia, left medial longitudinal fasciculus (MLF) syndrome, skew deviation, hypacusia, tongue deviation and left limb ataxia. Magnetic resonance imaging of the brain including diffusion-weighted imaging showed previous lacunar infarctions at the left thalamus and pons. The immunological investigation for viral infection in his serum samples showed high titers of IgM antibody against cytomegalovirus (CMV). Cerebrospinal fluid (CSF) investigation revealed mononuclear pleocytosis, elevated protein levels and high titers of IgG antibody against the varicella-zoster virus (VZV). Anti-CMV antibody measurement and CMV-DNA detection by the polymerase chain reaction in CSF revealed that the central nervous system (CNS) was not infected by CMV. We diagnosed this case as brainstem encephalitis following multiple cranial neuropathy associated with CMV and VZV infections. The neurological symptoms gradually improved with aciclovir and prednisolone therapy. The titers of antibody for CMV in his serum samples normalized 4 months later after onset. Although there was no evidence of CMV infection in the CNS was obtained, parainfection or autoimmune mediated responses followed by viral infections might have led to brainstem encephalitis with multiple cranial nerve involvements in our patient.