Neurocritical Care

, Volume 19, Issue 3, pp 336–341 | Cite as

Diagnostic Yield of Electroencephalography in the Medical and Surgical Intensive Care Unit

  • Hooman Kamel
  • John P. Betjemann
  • Babak B. Navi
  • Manu Hegde
  • Karl Meisel
  • Vanja C. Douglas
  • S. Andrew Josephson
Original Article



To determine the incidence of electrographic seizures during continuous electroencephalography (cEEG) in the medical and surgical ICU.


We retrospectively reviewed the records of all adults who underwent cEEG in our medical and surgical ICU over a 4.5 year period. Patients with acute brain injury were excluded. Our primary outcome was cEEG documentation of an electrographic seizure, defined as a rhythmic discharge or spike and wave pattern demonstrating definite evolution and lasting at least 10 s. To assess inter-rater variability in cEEG interpretation, two electrophysiologists independently reviewed all available cEEGs of subjects with electrographic seizures documented on their clinical cEEG report and those of an equal number of randomly selected subjects from the remaining cohort.


Kappa analysis showed a value of 0.88, indicating excellent inter-rater agreement. Electrographic seizures were identified in 12 of 105 patients (11 %, 95 % CI 5–18 %). This rate did not change after excluding patients with a history of seizure, remote brain injury, or seizure-like events before cEEG. In an ordinal logistic regression model controlling for age, sex, and SOFA score, electrographic seizures were associated with lower odds of good outcomes on the Glasgow Outcome Scale at discharge (OR 0.3, 95 % CI 0.1–0.8).


In a tertiary care medical and surgical ICU, electrographic seizures were seen on 11 % of cEEGs ordered for the evaluation of encephalopathy, and were associated with worse functional outcomes at discharge. Our findings confirm the results of a prior study suggesting a substantial burden of electrographic seizures in critically ill encephalopathic patients.


Encephalopathy Intensive care unit Seizure Status epilepticus Electroencephalography 





  1. 1.
    Pandian JD, Cascino GD, So EL, Manno E, Fulgham JR. Digital video-electroencephalographic monitoring in the neurological-neurosurgical intensive care unit: clinical features and outcome. Arch Neurol. 2004;61:1090–4.PubMedGoogle Scholar
  2. 2.
    Vespa P, Martin NA, Nenov V, et al. Delayed increase in extracellular glycerol with post-traumatic electrographic epileptic activity: support for the theory that seizures induce secondary injury. Acta Neurochir Suppl. 2002;81:355–7.PubMedGoogle Scholar
  3. 3.
    Towne AR, Waterhouse EJ, Boggs JG, et al. Prevalence of nonconvulsive status epilepticus in comatose patients. Neurology. 2000;54:340–5.PubMedCrossRefGoogle Scholar
  4. 4.
    Vespa PM, Nuwer MR, Nenov V, et al. Increased incidence and impact of nonconvulsive and convulsive seizures after traumatic brain injury as detected by continuous electroencephalographic monitoring. J Neurosurg. 1999;91:750–60.PubMedCrossRefGoogle Scholar
  5. 5.
    Claassen J, Jette N, Chum F, et al. Electrographic seizures and periodic discharges after intracerebral hemorrhage. Neurology. 2007;69:1356–65.PubMedCrossRefGoogle Scholar
  6. 6.
    Dennis LJ, Claassen J, Hirsch LJ, Emerson RG, Connolly ES, Mayer SA. Nonconvulsive status epilepticus after subarachnoid hemorrhage. Neurosurgery. 2002;51:1136–43. discussion 1144.PubMedCrossRefGoogle Scholar
  7. 7.
    Abend NS, Dlugos DJ, Hahn CD, Hirsch LJ, Herman ST. Use of EEG monitoring and management of non-convulsive seizures in critically ill patients: a survey of neurologists. Neurocrit Care. 2010;12:382–389.Google Scholar
  8. 8.
    Lowenstein DH, Aminoff MJ. Clinical and EEG features of status epilepticus in comatose patients. Neurology. 1992;42:100–4.PubMedCrossRefGoogle Scholar
  9. 9.
    Oddo M, Carrera E, Claassen J, Mayer SA, Hirsch LJ. Continuous electroencephalography in the medical intensive care unit. Crit Care Med. 2009;37:2051–6.PubMedCrossRefGoogle Scholar
  10. 10.
    Dellinger RP, Levy MM, Carlet JM, et al. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock: 2008. Crit Care Med. 2008;36:296–327.PubMedCrossRefGoogle Scholar
  11. 11.
    Vincent JL, Moreno R, Takala J, et al. The SOFA (sepsis-related organ failure assessment) score to describe organ dysfunction/failure. On behalf of the working group on sepsis-related problems of the European society of intensive care medicine. Intensive Care Med. 1996;22:707–10.PubMedCrossRefGoogle Scholar
  12. 12.
    Aminoff MJ. Electrodiagnosis in clinical neurology. 5th ed. London: Churchill Livingstone; 2005.Google Scholar
  13. 13.
    Jennett B, Snoek J, Bond MR, Brooks N. Disability after severe head injury: observations on the use of the Glasgow Outcome Scale. J Neurol Neurosurg Psychiatry. 1981;44:285–93.PubMedCrossRefGoogle Scholar
  14. 14.
    Husain AM, Horn GJ, Jacobson MP. Non-convulsive status epilepticus: usefulness of clinical features in selecting patients for urgent EEG. J Neurol Neurosurg Psychiatry. 2003;74:189–91.PubMedCrossRefGoogle Scholar
  15. 15.
    Vespa PM, O’Phelan K, Shah M, et al. Acute seizures after intracerebral hemorrhage: a factor in progressive midline shift and outcome. Neurology. 2003;60:1441–6.PubMedCrossRefGoogle Scholar
  16. 16.
    Claassen J, Mayer SA, Kowalski RG, Emerson RG, Hirsch LJ. Detection of electrographic seizures with continuous EEG monitoring in critically ill patients. Neurology. 2004;62:1743–8.PubMedCrossRefGoogle Scholar
  17. 17.
    Meldrum BS, Horton RW. Physiology of status epilepticus in primates. Arch Neurol. 1973;28:1–9.PubMedCrossRefGoogle Scholar
  18. 18.
    Sloviter RS. Decreased hippocampal inhibition and a selective loss of interneurons in experimental epilepsy. Science. 1987;235:73–6.PubMedCrossRefGoogle Scholar
  19. 19.
    Cock HR, Tong X, Hargreaves IP, et al. Mitochondrial dysfunction associated with neuronal death following status epilepticus in rat. Epilepsy Res. 2002;48:157–68.PubMedCrossRefGoogle Scholar
  20. 20.
    Pollard H, Charriaut-Marlangue C, Cantagrel S, et al. Kainate-induced apoptotic cell death in hippocampal neurons. Neuroscience. 1994;63:7–18.PubMedCrossRefGoogle Scholar
  21. 21.
    DeGiorgio CM, Correale JD, Gott PS, et al. Serum neuron-specific enolase in human status epilepticus. Neurology. 1995;45:1134–7.PubMedCrossRefGoogle Scholar
  22. 22.
    Rabinowicz AL, Correale JD, Bracht KA, Smith TD, DeGiorgio CM. Neuron-specific enolase is increased after nonconvulsive status epilepticus. Epilepsia. 1995;36:475–9.PubMedCrossRefGoogle Scholar
  23. 23.
    Salmenpera T, Kalviainen R, Partanen K, Mervaala E, Pitkanen A. MRI volumetry of the hippocampus, amygdala, entorhinal cortex, and perirhinal cortex after status epilepticus. Epilepsy Res. 2000;40:155–70.PubMedCrossRefGoogle Scholar
  24. 24.
    Chu K, Kang DW, Kim JY, Chang KH, Lee SK. Diffusion-weighted magnetic resonance imaging in nonconvulsive status epilepticus. Arch Neurol. 2001;58:993–8.PubMedCrossRefGoogle Scholar
  25. 25.
    Adachi N, Kanemoto K, Muramatsu R, et al. Intellectual prognosis of status epilepticus in adult epilepsy patients: analysis with Wechsler Adult Intelligence Scale-revised. Epilepsia. 2005;46:1502–9.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Hooman Kamel
    • 1
  • John P. Betjemann
    • 2
  • Babak B. Navi
    • 1
  • Manu Hegde
    • 2
  • Karl Meisel
    • 2
  • Vanja C. Douglas
    • 2
  • S. Andrew Josephson
    • 2
  1. 1.Department of Neurology and NeuroscienceWeill Cornell Medical CollegeNew YorkUSA
  2. 2.Department of NeurologyUniversity of CaliforniaSan FranciscoUSA

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