title: Approximate entropy of the electroencephalogram in healthy awake subjects and absence epilepsy patients.
abstract: The approximate entropy (ApEn) of signals in the electroencephalogram (EEG) was evaluated in 8 healthy volunteers and in 10 patients with absence epilepsy, both during seizure-free and seizure intervals. We estimated the nonlinearity of each 3-sec EEG segment using surrogate data methods. The mean (+/- SD) ApEn in EEG was 0.83 +/- 0.22 in healthy subjects awake with eyes closed. It was significantly lower during epileptic seizures (0.48 +/- 0.05) than during seizure-free intervals (0.80 +/- 0.13) (P < 0.001). Nonlinearity was clearly detected in EEG signals from epileptic patients during seizures but not during seizure-free intervals or in EEG signals from healthy subjects. The ApEn of EEG signals estimated over consecutive intervals could serve to determine pathological brain activity such as that occurring during absence epilepsy.
authors.affiliation: Division of Medical Oncology and Molecular Respirology, Faculty of Medicine, Tottori University, 36-1 Nishimachi, Yonago 683-8504, Japan. burioka@grape.med.tottori-u.ac.jp
authors.forename: Naoto
authors.initials: N
authors.lastname: Burioka
authors.forename: Germaine
authors.initials: G
authors.lastname: Cornélissen
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Maegaki
authors.forename: Franz
authors.initials: F
authors.lastname: Halberg
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Kaplan
authors.forename: Masanori
authors.initials: M
authors.lastname: Miyata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Fukuoka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Endo
authors.forename: Hisashi
authors.initials: H
authors.lastname: Suyama
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tomita
authors.forename: Eiji
authors.initials: E
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D002648:Child; D004569:Electroencephalography; D004832:Epilepsy, Absence / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests