Bicoherence of Intracranial EEG: A Novel Precursor of Seizure Activity in Canine Epilepsy

Abstract

Seizure forecasting relies on the adequate identification of seizure activity precursors from electroencephalography (EEG). This work evaluates the suitability of the bicoherence, a measure of non-linear phase-phase coupling based on the higher order spectra (HOS), for seizure prediction in canine epilepsy. Quantitative features were extracted from the bicoherence of recordings and statistical tests assessed the existence of significant differences between preictal and interictal HOS features. Results displayed a statistically significant HOS change during the preictal period in both hemispheres for all 3 dogs diagnosed with focal epilepsy. This work demonstrates the existence of a preictal period characterized by a statistically significant change in bicoherence, highlighting the feasibility of seizure forecasting based on HOS features.