To describe vignettes of neuroinvasive West Nile associated disease (N-WNAD) successfully treated with intravenous immunoglobulin (IVIG).

Most West Nile virus (WNV) infections are asymptomatic. However, 1% of infected individuals develop N-WNAD including meningitis, encephalitis, and acute flaccid paralysis. Overall case fatality is 5-10%. While supportive care is considered the current standard of care, earlier studies suggested a possible role for IVIG.

Case series and literature review.

Patient-1, A young man in his twenties developed headaches, severe cognitive and memory alterations, and opsoclonus myoclonus after spending time in Wisconsin. IgM antibodies were detected in spinal fluid and serum against WNV. MRI brain was unrevealing. Timely IVIG and dexamethasone administration resulted in progressive improvement. Six months later, he had complete resolution of all neurological symptoms.  Patient-2, An older man in his eighties developed fever, disorientation, and vomiting after spending time in Michigan. IgM antibodies were detected in spinal fluid and serum against WNV. MRI brain showed bilateral T2-hyperintensity in temporal lobes. Mentation worsened over time to the point that he developed a catatonic state. Electroencephalogram revealed no seizures. Supportive care did not improve his cognitive symptoms. However, following the administration of IVIG, his mentation improved, though waxed and waned; he became partially oriented, started talking, and followed simple commands. MRI brain showed resolution of bitemporal hyperintensities.

Current research showed mixed interpretations of the role of IVIG use in N-WNAD. Both clinical and preclinical studies have alluded to a possible beneficial role for IVIG treatment. However, a small phase-II randomized trial failed to establish a benefit from IVIG treatment.

Our observation is in-line with other clinical reports of successful use of IVIG in the treatment of N-WNAD. This calls for further multi-center studies to identify characteristics of patients who may benefit from this treatment.