title: Slow modulations of high-frequency activity (40-140-Hz) discriminate preictal changes in human focal epilepsy.
abstract: 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.affiliation: Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM) INSERM UMRS 975 - CNRS UMR 7225-UPMC, Hôpital de la Pitié-Salpêtrière, Paris, FRANCE.
authors.forename: C
authors.initials: C
authors.lastname: Alvarado-Rojas
authors.affiliation: Department of Biomedical Engineering, Universidad de Los Andes, Bogotá, COLOMBIA.
authors.forename: M
authors.initials: M
authors.lastname: Valderrama
authors.affiliation: Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM) INSERM UMRS 975 - CNRS UMR 7225-UPMC, Hôpital de la Pitié-Salpêtrière, Paris, FRANCE.
authors.forename: A
authors.initials: A
authors.lastname: Fouad-Ahmed
authors.affiliation: 1] Bernstein Center Freiburg, University of Freiburg, Freiburg, GERMANY [2] Freiburg Center for Data Analysis and Modeling, University of Freiburg, GERMANY [3] Epilepsy Center, University Hospital of Freiburg, GERMANY [4] Department of Neurobiology and Biophysics, Faculty of Biology, University of Freiburg, Freiburg, GERMANY.
authors.forename: H
authors.initials: H
authors.lastname: Feldwisch-Drentrup
authors.affiliation: Epilepsy Center, University Hospital of Freiburg, GERMANY.
authors.forename: M
authors.initials: M
authors.lastname: Ihle
authors.affiliation: CISUC-Centro de Informatica e Sistemas da Universidade de Coimbra, Faculty of Sciences and Technology, University of Coimbra, Coimbra, PORTUGAL.
authors.forename: C A
authors.initials: CA
authors.lastname: Teixeira
authors.affiliation: Hospitais da Universidade de Coimbra, PORTUGAL.
authors.forename: F
authors.initials: F
authors.lastname: Sales
authors.affiliation: 1] Bernstein Center Freiburg, University of Freiburg, Freiburg, GERMANY [2] Epilepsy Center, University Hospital of Freiburg, GERMANY.
authors.forename: A
authors.initials: A
authors.lastname: Schulze-Bonhage
authors.affiliation: 1] Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM) INSERM UMRS 975 - CNRS UMR 7225-UPMC, Hôpital de la Pitié-Salpêtrière, Paris, FRANCE [2] AP-HP, Epilepsy Unit, Groupe Hospitalier Pitié-Salpêtrière, FRANCE.
authors.forename: C
authors.initials: C
authors.lastname: Adam
authors.affiliation: CISUC-Centro de Informatica e Sistemas da Universidade de Coimbra, Faculty of Sciences and Technology, University of Coimbra, Coimbra, PORTUGAL.
authors.forename: A
authors.initials: A
authors.lastname: Dourado
authors.affiliation: Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM) INSERM UMRS 975 - CNRS UMR 7225-UPMC, Hôpital de la Pitié-Salpêtrière, Paris, FRANCE.
authors.forename: S
authors.initials: S
authors.lastname: Charpier
authors.affiliation: 1] Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM) INSERM UMRS 975 - CNRS UMR 7225-UPMC, Hôpital de la Pitié-Salpêtrière, Paris, FRANCE [2] AP-HP, Epilepsy Unit, Groupe Hospitalier Pitié-Salpêtrière, FRANCE.
authors.forename: V
authors.initials: V
authors.lastname: Navarro
authors.affiliation: Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière (CRICM) INSERM UMRS 975 - CNRS UMR 7225-UPMC, Hôpital de la Pitié-Salpêtrière, Paris, FRANCE.
authors.forename: M
authors.initials: M
authors.lastname: Le Van Quyen
mesh_terms: D000293:Adolescent; D000328:Adult; D058256:Brain Waves; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult