title: Yield of intermittent versus continuous EEG in comatose survivors of cardiac arrest treated with hypothermia.
abstract: BACKGROUND
  Electroencephalography (EEG) has a central role in the outcome prognostication in subjects with anoxic/hypoxic encephalopathy following a cardiac arrest (CA). Continuous EEG monitoring (cEEG) has been consistently developed and studied; however, its yield as compared to repeated standard EEG (sEEG) is unknown.
  
  
  METHODS
  We studied a prospective cohort of comatose adults treated with therapeutic hypothermia (TH) after a CA. cEEG data regarding background activity and epileptiform components were compared to two 20-minute sEEGs extracted from the cEEG recording (one during TH, and one in early normothermia).
  
  
  RESULTS
  Thirty-four recordings were studied. During TH, the agreement between cEEG and sEEG was 97.1% (95% CI: 84.6 to 99.9%) for background discontinuity and reactivity evaluation, while it was 94.1% (95% CI 80.3 to 99.2%) regarding epileptiform activity. In early normothermia, we did not find any discrepancies. Thus, concordance results were very good during TH (kappa 0.83), and optimal during normothermia (kappa = 1). The median delay between CA and the first EEG reactivity testing was 18 hours (range: 4.75 to 25) for patients with perfect agreement and 10 hours (range: 5.75 to 10.5) for the three patients with discordant findings (P = 0.02, Wilcoxon).
  
  
  CONCLUSIONS
  Standard intermittent EEG has comparable performance with continuous EEG both for variables important for outcome prognostication (EEG reactivity) and identification of epileptiform transients in this relatively small sample of comatose survivors of CA. This finding has an important practical implication, especially for centers where EEG resources are limited.
authors.forename: Vincent
authors.initials: V
authors.lastname: Alvarez
authors.forename: Alba
authors.initials: A
authors.lastname: Sierra-Marcos
authors.forename: Mauro
authors.initials: M
authors.lastname: Oddo
authors.forename: Andrea O
authors.initials: AO
authors.lastname: Rossetti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003128:Coma / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017741:Survivors; D016896:Treatment Outcome; D014741:Video Recording / Q000379:methods