Quantification of high frequency oscillations in preictal dynamic states

MAURO GRANADO; FERNANDO MONTANI; ROMAN BARAVALLE

Buenos Aires

Conferencia; 27th International Conference on Statistical Physics, StatPhys 27; 2019

IUPAP

In the mesoscale of brain activity, the LFP signals reproduce an integrated version of spikes, and therefore represent the activity from many nearby neurons registered by the microelectrodes in the intracranial electroencephalography (iEEG) recordings, which provides information about the neuronal network. On the other hand, in the macroscale of the iEEG, the signals have the typical forms, such as interictal discharges, ictal or even high frequency oscillations (HFO). We estimate the intrinsic correlation structure of iEEG signals within the Complexity versus Entropy plane, and of the Entropy versus Fisher Information plane. We investigated the intrinsic dynamics of iEEG signals for preictal times to the crisis episode of epilepsy, identifying the frequency band for which the transmission of information is optimal, which will allow us to evaluate its possible role as epileptic biomarkers. Importantly, we found gamma resonant peaks in the power spectral density that are present in the preictal but not in the basal state. This finding allows us to conclude that these resonances, corresponding to high frequency oscillations, could be the precursors of the ictal state emphasizing the role of the HFOs in the transition from preictal to ictal in epileptic patiens.