West Nile viral encephalitis mimicking hepatic encephalopathy

West Nile encephalitis (WNE) has become endemic in the United States since 1999. The clinical spectrum of WNE includes aseptic meningitis, meningoencephalitis, or encephalitis with or without flaccid paralysis. The severity of WNE ranges from asymptomatic serum conversion to severe neurologic deficits or a fatal outcome. Several systemic disorders may present with encephalitis as part of the clinical presentation, for example, Legionnaires' disease, neoplasms with metastases to the central nervous system, Mycoplasma meningoencephalitis, brucellosis, Listeria, Rocky Mountain spotted fever, ehrlichiosis, and malaria. The most common infectious causes of encephalitis that need to be differentiated from WNE include herpes simplex virus 1, meningoencephalitis, and enteroviral meningoencephalitis. We present a case of apparent hepatic encephalopathy secondary to pancreatic carcinoma with liver involvement that presented as hepatic encephalopathy mimicking WNE. We conclude that patients presenting with encephalitis in the summer months should have serum/cerebrospinal fluid serologic studies sent for WNE even if an alternate explanation seems to explain the clinical syndrome.