Opsomyoclonus: A rare complication of West Nile virus.

West Nile virus is a mosquito-borne illness that usually presents as asymptomatic or with a viral syndrome, and normally is treated with supportive care or immunotherapy. However, some patients can develop neurologic symptoms of viral meningoencephalitis. This article describes a patient who developed opsomyoclonus, a rare complication of West Nile virus meningoencephalitis. She was treated with immunotherapy with no resolution of her symptoms. Symptom improvement occurred with subsequent treatment with clonazepam and dexamethasone.