A 70-year-old West Texas woman presented with progressive neurological symptoms including confusion, ataxia, and expressive aphasia, initially suspected to be a cerebrovascular accident. Her condition worsened, developing seizures and coma. Brain imaging revealed diffuse encephalitis, and extensive diagnostic workup, including CSF analysis and serology, was performed. Ultimately, serological testing confirmed West Nile virus (WNV) infection, specifically IgM antibodies in cerebrospinal fluid. This case highlights the importance of considering arboviral encephalitis, particularly WNV, in patients with unexplained neurological deterioration in endemic regions, even in the absence of typical seasonal presentation. Prompt and accurate diagnosis is crucial for appropriate management.
Key note: West Nile virus encephalitis should be considered in elderly patients with unexplained neurological deterioration, even outside typical seasons, especially in endemic areas.