Continuous electroencephalography in the medical intensive care unit

Mauro Oddo, Emmanuel Carrera, Jan Claassen, Stephan A. Mayer, Lawrence J. Hirsch

Research output: Contribution to journalArticlepeer-review

310 Scopus citations


Objectives: 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. Design: Retrospective study. Setting: MICU in a university hospital. Patients: 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. Intervention: None. Measurements and main 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). Conclusion: 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.

Original languageEnglish
Pages (from-to)2051-2056
Number of pages6
JournalCritical Care Medicine
Issue number6
StatePublished - May 2009
Externally publishedYes


  • Acute brain dysfunction
  • Electrographic seizures
  • ICU delirium
  • Medical ICU
  • Nonconvulsive seizures
  • Outcome
  • Sepsis-associated encephaloapathy
  • Septic encephalopathy


Dive into the research topics of 'Continuous electroencephalography in the medical intensive care unit'. Together they form a unique fingerprint.

Cite this