title: Encephalitis and postinfectious encephalitis.
abstract: OBJECTIVE
  Encephalitis and postinfectious encephalitis represent two important conditions for the neurologist, both in terms of their presentations as neurologic emergencies and their potential to cause death or serious neurologic impairment. This article reviews the major infectious and noninfectious causes of encephalitis and discusses postinfectious encephalitis as an indirect effect of systemic illness.
  
  
  RESULTS
  Encephalitis caused by herpes simplex virus type 1 and West Nile virus are of major importance. In addition, within the past few years we have gained improved understanding of the neurologic syndromes caused by varicella-zoster virus, the recognition of enterovirus 71 as a significant human pathogen, and the realization that encephalitis may also occur by autoimmune mechanisms requiring immunosuppressive therapy. We have also learned that postinfectious encephalitis may be recurrent rather than monophasic, and that children and adults initially diagnosed with postinfectious encephalitis may later develop classic multiple sclerosis.
  
  
  CONCLUSIONS
  Encephalitis and postinfectious encephalitis present as neurologic emergencies requiring prompt diagnosis and initiation of treatment. Important concerns are to identify infectious conditions requiring antibiotic or antiviral therapy and postinfectious or other autoimmune encephalitides requiring immunosuppression.
authors.affiliation: University of Utah, Clinical Neuroscience Center, 175 North Medical Dr E, Salt Lake City, UT 84132, USA. john.greenlee@hsc.utah.edu
authors.forename: John E
authors.initials: JE
authors.lastname: Greenlee
mesh_terms: D000212:Acyclovir / Q000627:therapeutic use; D000293:Adolescent; D000998:Antiviral Agents / Q000627:therapeutic use; D001927:Brain Diseases / Q000175:diagnosis / Q000209:etiology; D004660:Encephalitis / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D020803:Encephalitis, Herpes Simplex / Q000175:diagnosis / Q000188:drug therapy; D020804:Encephalitis, Varicella Zoster / Q000175:diagnosis / Q000188:drug therapy; D018792:Encephalitis, Viral / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D004769:Enterovirus Infections / Q000175:diagnosis / Q000821:virology; D017809:Fatal Outcome; D005260:Female; D050031:Hashimoto Disease / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D004684:Leukoencephalitis, Acute Hemorrhagic / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014901:West Nile Fever / Q000175:diagnosis / Q000821:virology; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D000212:Acyclovir