Nonlinear EEG analysis in epilepsy: Its possible use for interictal focus localization, seizure anticipation, and prevention

Several recent studies emphasize the high value of nonlinear EEG analysis p articularly for improved characterization of epileptic brain states. In thi s review the authors report their work to increase insight into the spatial and temporal dynamics of the epileptogenic process. Specifically, they dis cuss possibilities for seizure anticipation, which is one of the most chall enging aspects of epileptology. Although there are numerous studies explori ng basic neuronal mechanisms that are likely to be associated with seizures , to date no definite information is available regarding how, when, or why a seizure occurs. Nonlinear EEG analysis now provides strong evidence that the interictal-ictal state transition is not an abrupt phenomenon. Rather, findings indicate that it is indeed possible to detect a preseizure phase. The unequivocal definition of such a state with a sufficient length would e nable investigations of basic mechanisms leading to seizure initiation in h umans, and development of adequate seizure prevention strategies.