High-frequency components in epileptiform EEG.

We analyzed the spectral content of interictal and ictal EEG of rats treated with metrazol. Significant power was present in the EEG between 100 and 800 Hz ictally but not interictally. Since high-frequency activities appeared to accompany spiking episodes, a computer algorithm was developed to recognize rapid voltage fluctuations or high-frequency components in EEG. The algorithm turned out to be effective in the identification of seizure spikes. The significance of high frequencies in EEG spikes and the advantage of the spike selection algorithm are discussed.