title: Acute hemorrhagic leukoencephalitis and hypoxic brain injury associated with H1N1 influenza.
abstract: OBJECTIVE
  To describe the first adult with neurologic complications associated with H1N1 influenza virus infection.
  
  
  METHODS
  Case report. Patient A 40-year-old man with severe H1N1 influenza infection with prolonged hypoxia and critical illness who remained comatose after withdrawal of sedatives and paralytics.
  
  
  METHODS
  Clinical examination and magnetic resonance imaging.
  
  
  RESULTS
  Brain imaging revealed multifocal T2 hyperintense lesions, edema, and hemorrhages consistent with acute hemorrhagic leukoencephalitis (AHL) and restricted diffusion in the basal ganglia consistent with hypoxic brain injury. The patient remained in a severely disabled state following treatment with plasma exchange and high-dose corticosteroids.
  
  
  CONCLUSIONS
  This is the first study of neurologic complications associated with H1N1 influenza infection in adults. Severe brain injury can occur by 2 distinct mechanisms: a fulminant autoimmune demyelinating insult (AHL) and hypoxic brain injury. Clinicians should be aware of these potential complications so that appropriate imaging and treatment can be considered.
authors.affiliation: Department of Neurology, West 8B, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Fugate
authors.forename: Erek M
authors.initials: EM
authors.lastname: Lam
authors.forename: Alejandro A
authors.initials: AA
authors.lastname: Rabinstein
authors.forename: Eelco F M
authors.initials: EF
authors.lastname: Wijdicks
mesh_terms: D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D006801:Humans; D002534:Hypoxia, Brain / Q000175:diagnosis / Q000209:etiology* / Q000821:virology; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications*; D004684:Leukoencephalitis, Acute Hemorrhagic / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D009460:Neurologic Examination