The first-hour-of-the-day sleep EEG reliably identifies interictal epileptiform discharges during long-term video-EEG monitoring

Seizure. 2018 Dec:63:48-51. doi: 10.1016/j.seizure.2018.10.015. Epub 2018 Oct 26.


Purpose: To determine the usefulness of the first-hour sleep EEG recording in identifying interictal epileptiform discharges (IEDs) during long-term video-EEG monitoring.

Method: We retrospectively reviewed 255 consecutive patients who underwent continuous long-term video-EEG monitoring in the adult epilepsy monitoring unit (EMU) at the University of Chicago. The complete video-EEG recording was reviewed, and the occurrence of IEDs was determined for each patient. We compared the occurrence of IEDs observed during the first-hour sleep EEG recordings with the occurrence of IEDs observed during the complete video-EEG recordings.

Results: Overall, IEDs were observed in 134 (53%) of 255 patients during the full long-term video-EEG recording with a mean duration of 4 days. IEDs were identified in the first-hour sleep EEG in 125 (49%) of 225 patients. Comparing to reviewing full records, the first hour sleep EEG identified IEDs in 125 (93%) of 134 patients. Of the IED subtypes, the first-hour sleep EEG identified 92 (94%) of 98 patients with temporal lobe IEDs, 11 (92%) of 12 patients with frontal lobe IEDs, 3 (100%) of 3 patients with parietal lobe IEDs, 1(50%) of the 2 patients with occipital lobe IEDs, 16 (94%) of 17 patients with generalized IEDs, and 2 (100%) 2 patients with multi-focal IEDs.

Conclusions: The first-hour sleep EEG reliably predicts the occurrence of IEDs during the long-term video-EEG recording, and therefore can be a time-efficient tool for identifying patients with IEDs during long-term video-EEG recording in the adult epilepsy monitoring unit.

Keywords: Epilepsy monitoring unit; Interictal epileptiform discharges; Seizures; Sleep; Video-EEG monitoring.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Brain / physiopathology*
  • Electroencephalography*
  • Epilepsy / diagnosis*
  • Epilepsy / physiopathology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neurophysiological Monitoring
  • Polysomnography
  • Reproducibility of Results
  • Retrospective Studies
  • Sleep / physiology*
  • Time Factors
  • Video Recording
  • Young Adult