West Nile Virus Neuroinvasive Disease: Lessons From Two Cases.

Background and objective: West Nile neuroinvasive disease (WNND) displays a wide range of clinical manifestations due to its involvement of various structures within the central nervous system and peripheral nervous system, often including prolonged unresponsiveness as the presenting symptom.

Methods and results: We describe 2 patients presenting with coma and bilateral thalamic lesions on brain magnetic resonance imaging, found to have WNND after extensive workup. These cases illustrate some of the challenges associated with evaluating coma in general and specifically in diagnosing WNND.

Conclusion: The clinical diagnosis of WNND requires a high index of suspicion, particularly in immunocompromised and elderly patients. Brain and spine magnetic resonance imaging findings can help narrow down the differential diagnosis, although other diseases may manifest similarly. Serological studies on the cerebrospinal fluid are essential to confirm the diagnosis but have inherent limitations. Given these challenges, WNND should be considered in all patients living in endemic areas who present with unexplained altered mental status during the late summer and early fall seasons.