title: Electroencephalography for diagnosis and prognosis of acute encephalitis.
abstract: OBJECTIVE
  To confirm the previously identified EEG characteristics for HSV encephalitis and to determine the diagnostic and predictive value of electroencephalography (EEG) features for etiology and outcome of acute encephalitis in adults. In addition, we sought to investigate their independence from possible clinical confounders.
  
  
  METHODS
  This study was performed in the Intensive Care Units of two academic tertiary care centers. From 1997 to 2011, all consecutive patients with acute encephalitis who received one or more EEGs were included. Examination of the diagnostic and predictive value of EEG patterns regarding etiology, clinical conditions, and survival was performed. The main outcome measure was in-hospital death.
  
  
  RESULTS
  Of 103 patients with encephalitis, EEGs were performed in 76 within a median of 1 day (inter quartile range 0.5-3) after admission. Mortality was 19.7%. Higher proportions of periodic discharges (PDs) (p=0.029) and focal slowing (p=0.017) were detected in Herpes Simplex virus (HSV) encephalitis as compared to non-HSV encephalitis, while clinical characteristics did not differ. Normal EEG remained the strongest association with a low relative risk for death in multivariable analyses (RR<0.001, p<0.001) adjusting for confounders as coma, global cerebral edema and mechanical ventilation. None of the patients with a normal EEG had a GCS of 15.
  
  
  CONCLUSIONS
  Normal EEG predicted survival independently from possible confounders, highlighting the prognostic value of EEG in evaluating patients with encephalitis. EEG revealed higher proportions of PDs along with focal slowing in HSV encephalitis as compared to other etiologies.
  
  
  CONCLUSIONS
  EEG significantly adds to clinical, diagnostic and prognostic information in patients with acute encephalitis.
authors.affiliation: Division of Neurosciences Critical Care, Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, MD, USA; Department of Neurology University Hospital Basel, Basel, Switzerland; Clinic of Intensive Care Medicine, University Hospital Basel, Basel, Switzerland. Electronic address: Raoul.Sutter@usb.ch.
authors.forename: Raoul
authors.initials: R
authors.lastname: Sutter
authors.affiliation: Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, MD, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kaplan
authors.affiliation: Division of Epilepsy, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Mackenzie C
authors.initials: MC
authors.lastname: Cervenka
authors.affiliation: Johns Hopkins Encephalitis Center, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Kiran T
authors.initials: KT
authors.lastname: Thakur
authors.affiliation: Johns Hopkins Encephalitis Center, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Asemota
authors.affiliation: Johns Hopkins Encephalitis Center, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Venkatesan
authors.affiliation: Division of Neurosciences Critical Care, Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Johns Hopkins Encephalitis Center, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Romergryko G
authors.initials: RG
authors.lastname: Geocadin
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D004660:Encephalitis / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011379:Prognosis
keywords: EEG patterns; Electroencephalography; Encephalitis; Neurocritical care