Extreme events on EEG signals of rodents with induced stroke

In present work we studied extreme events that occur on elecroencephalogram of rodents with induced stroke. These events were registered as epileptic seizures with form of sudden high-amplitude oscillations, that emerge during first 2-3 hours after the stroke. Time-frequency structure analysis of electroencephalogram showed, that extreme events manifest themselves as sharp increase in wavelet energy distribution for characteristic frequency range. At the same time, wavelet energy in the rest part of spectrum remained unchanged. Revealed distinct features of extreme events were used for their detection on electroencephalogram. Quantification of extreme behaviour was held with help of construction of probability distribution functions for wavelet energy maxima and their approximation with different analitical distribution functions.