Influenza A virus-associated acute necrotizing encephalopathy in the United States.

During the past several years, influenza-associated acute necrotizing encephalopathy has been well-recognized in Asia but has not yet been reported in the United States. We describe a 28-month-old patient who displayed the classical clinical features of acute necrotizing encephalopathy in association with a documented influenza A infection. This disease is characterized by fever, a rapid alteration in consciousness and seizures, with radiologic involvement of the bilateral thalami and cerebellum.