An autoregressive method for the measurement of synchronization of interictal and ictal EEG signal.
1Maryland Epilepsy Center, Department of
Neurology, University of Maryland School of Medicine and Medical
Center, Baltimore, Maryland 21201, USA.
2Department of Physiology, University of Maryland
School of Medicine, Baltimore, Maryland 21201, USA.
We propose a new measure of synchronization of multichannel ictal and interictal EEG signals. The measure is based on the residual covariance matrix of a multichannel autoregressive model. A major advantage of this measure is its ability to be interpreted both in the framework of stochastic and deterministic models. A preliminary analysis of EEG data from three patients using this measure documents the expected increased synchronization during ictal periods but also reveals that increased synchrony persists for prolonged periods (up to 2 hours or more) in the postictal period.
Biological Cybernetics, 81, 3-9 (1999).