We report an immunocompetent patient who had fatal encephalopathy after mild influenza. He rapidly died after unusual symptoms related to intracerebral thrombosis and hemorrhage. A brain biopsy specimen was positive for influenza A(H1N1)pdm09 virus RNA, but a lung biopsy specimen and cerebrospinal spinal fluid samples were negative.
Keywords: adult; cerebral venous thrombosis; encephalitis; encephalopathy; influenza; influenza A(H1N1)pdm09; influenza virus; neurologic complication; seizure; viruses.