Discerning nonstationarity from nonlinearity in seizure-free and preseizure EEG recordings from epilepsy patients.
A number of recent studies indicate that nonlinear electroencephalogram (EEG) analyses allow to define a state predictive of an impending epileptic seizure. In this paper, we combine a method for detecting nonlinear determinism with a novel test for stationarity to characterize EEG recordings from both the seizure-free interval and the preseizure phase. We discuss differences between these periods, particularly an increased occurrence of stationary, nonlinear segments prior to seizures. These differences seem most prominent for recording sites within the seizure-generating area and for EEG segments less than one minute's length.
Rieke
Christoph
C
Department of Epileptology, University of Bonn, Sigmund Freud Str.25, 53105 Bonn, Germany. rieke@iskp.uni-bonn.de
Mormann
Florian
F
Andrzejak
Ralph G
RG
Kreuz
Thomas
T
David
Peter
P
Elger
Christian E
CE
Lehnertz
Klaus
K
D004569:Electroencephalography / Q000379:methods*; D004828:Epilepsies, Partial / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D017711:Nonlinear Dynamics; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012640:Seizures / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D013269:Stochastic Processes