An Atypical Presentation of West Nile Virus With Successful Treatment After Plasma Exchange and Intravenous Immunoglobulin.

West Nile (WN) disease is a relatively rare arboviral virus. Neuroinvasive cases of WN account for less than 1% of the total cases. The case described had difficult symptomatology and radical presentation, which included ascending paralysis. To date, there have been very few reports of West Nile cases that present with ascending paralysis. We describe the case of a 63-year-old white male who presented with a fever and proximal muscle weakness in the thighs and legs that rapidly worsened and ascended, eventually resulting in diaphragmatic paralysis. He was intubated after respiratory failure and given intravenous immunoglobulin and plasma exchange. The patient remained ventilated with persistent weakness. However, this improved after intravenous immunoglobulin and plasma exchange therapy. This case serves as a reminder to keep the diagnosis of WN on the differential, a primer on advanced treatments in the setting of aggressive atypical WN, and a lesson on similarly presenting diseases and distinguishing characteristics that may help rule out these diseases from WN.