A thalamus-to-cortex seizure pathway: a new coherence approach using sinusoidal modelling

A new method of measuring coherence between EEG channels is proposed for modeling the level of linear association during epileptic seizures. This method relies upon modelling the clonic seizure activity as a sum of sinusoids. The authors estimate contributions from correlated and uncorrelated sinusoidal components from information contained in auto- and cross-correlation matrices. Coherence estimates are formed from the ratio of correlated to total power. The authors illustrate the value of this method by examination of the strength of correlation between seizure EEG from specific thalamic nuclei and cortex in an animal model of generalized epilepsy.