The patient was a 70-year-old man seen for a two-day history of headaches and changes in mental status. The examination did not reveal any other conditions beyond subtle personality changes. A CSF demonstrated 419 cells/µL, normal glucose, and increased protein of 93 mg/dL. He was given antimicrobial agents for bacterial and herpetic meningitis. Two days after treatment began, he developed a fever, his mental status deteriorated, and he required intubation. He was admitted to the ICU when he developed left-sided weakness.
Eleven days later, WNV IgM was positive at a titer of 1:8. He was diagnosed with West Nile encephalitis. He was hospitalized for 42 days. After discharge, he had residual left-sided weakness, but his mental status was normal.
