Slow modulations of high-frequency activity (40-140-Hz) discriminate preictal changes in human focal epilepsy.

Academic Article


  • Recent evidence suggests that some seizures are preceded by preictal changes that start from minutes to hours before an ictal event. Nevertheless an adequate statistical evaluation in a large database of continuous multiday recordings is still missing. Here, we investigated the existence of preictal changes in long-term intracranial recordings from 53 patients with intractable partial epilepsy (in total 531 days and 558 clinical seizures). We describe a measure of brain excitability based on the slow modulation of high-frequency gamma activities (40-140 Hz) in ensembles of intracranial contacts. In prospective tests, we found that this index identified preictal changes at levels above chance in 13.2% of the patients (7/53), suggesting that results may be significant for the whole group (p < 0.05). These results provide a demonstration that preictal states can be detected prospectively from EEG data. They advance understanding of the network dynamics leading to seizure and may help develop novel seizure prediction algorithms.
  • Authors

    Published In

  • Scientific Reports  Journal
  • Keywords

  • Adolescent, Adult, Brain Waves, Child, Child, Preschool, Electroencephalography, Epilepsies, Partial, Female, Humans, Male, Middle Aged, Young Adult
  • Digital Object Identifier (doi)

    Author List

  • Alvarado-Rojas C; Valderrama M; Fouad-Ahmed A; Feldwisch-Drentrup H; Ihle M; Teixeira CA; Sales F; Schulze-Bonhage A; Adam C; Dourado A
  • Start Page

  • 4545
  • Volume

  • 4