title: Continuous electroencephalography in the medical intensive care unit.
abstract: OBJECTIVE
  To examine predictors and the prognostic value of electrographic seizures (ESZs) and periodic epileptiform discharges (PEDs) in medical intensive care unit (MICU) patients without a primary acute neurologic condition.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  MICU in a university hospital.
  
  
  METHODS
  A total of 201 consecutive patients admitted to the MICU between July 2004 and January 2007 without known acute neurologic injury and who underwent continuous electroencephalography monitoring (cEEG) for investigation of possible seizures or changes in mental status.
  
  
  METHODS
  None.
  
  
  RESULTS
  Median time from intensive care unit (ICU) admission to cEEG was 1 day (interquartile range 1-4). The majority of patients (60%) had sepsis as the primary admission diagnosis and 48% were comatose at the time of cEEG. Ten percent (n = 21) of patients had ESZs, 17% (n = 34) had PEDs, 5% (n = 10) had both, and 22% (n = 45) had either ESZs or PEDs. Seizures during cEEG were purely electrographic (no detectable clinical correlate) in the majority (67%) of patients. Patients with sepsis had a higher rate of ESZs or PEDs than those without sepsis (32% vs. 9%, p < 0.001). On multivariable analysis, sepsis at ICU admission was the only significant predictor of ESZs or PEDs (odds ratio 4.6, 95% confidence interval 1.9-12.7, p = 0.002). After controlling for age, coma, and organ dysfunction, the presence of ESZs or PEDs was associated with death or severe disability at hospital discharge (89% with ESZs or PEDs, vs. 39% if not; odds ratio 19.1, 95% confidence interval 6.3-74.6, p < 0.001).
  
  
  CONCLUSIONS
  In this retrospective study of MICU patients monitored with cEEG, ESZs and PEDs were frequent, predominantly in patients with sepsis. Seizures were mainly nonconvulsive. Both seizures and periodic discharges were associated with poor outcome. Prospective studies are warranted to determine more precisely the frequency and clinical impact of nonconvulsive seizures and periodic discharges, particularly in septic patients.
authors.affiliation: Department of Neurology, Division of Critical Care, Neurological Institute, Columbia University Medical Center, New York, New York, USA.
authors.forename: Mauro
authors.initials: M
authors.lastname: Oddo
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Carrera
authors.forename: Jan
authors.initials: J
authors.lastname: Claassen
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Mayer
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Hirsch
mesh_terms: D000368:Aged; D001927:Brain Diseases / Q000175:diagnosis* / Q000209:etiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012640:Seizures / Q000175:diagnosis* / Q000209:etiology*; D018805:Sepsis / Q000150:complications* / Q000503:physiopathology*