Analysis of Absence Epileptic Seizures Using Depth Cortical Measurements

Analyse des Crises d’Epilepsie à l’Aide de Mesures de Profondeur

Saeed Akhavanbahabadi (1)

1 GIPSA-VIBS - GIPSA - Vision and Brain Signal Processing

Absence epilepsy syndrome is accompanied with sudden appearance of seizures in different regions of the brain. The sudden generalization of absence seizures to every region of the brain shows the existence of a mechanism which can quickly synchronizes the activities of the majority of neurons in the brain. The presence of such a mechanism challenges our information about the integrative properties of neurons and the functional connectivity of brain networks. For this reason, many researchers have tried to recognize the main origin of absence seizures. Recent studies have suggested a theory regarding the origin of absence seizures which states that somatosensory cortex drives the thalamus during the first cycles of absence seizures, while thereafter, cortex and thalamus mutually drive each other and continue absence seizures.This theory motivated the neuroscientists in Grenoble Institute of Neurosciences (GIN) to record data from different layers of somatosensory cortex of Genetic Absence Epilepsy Rats from Strasbourg (GAERS), which is a well-validate animal model for absence epilepsy, to explore the main starting region of absence seizures locally. An electrode with E = 16 sensors was vertically implanted in somatosensory cortex of GAERS, and potentials were recorded. In this study, we aim to localize the onset layers of somatosensory cortex during absence seizures and investigate the temporal evolution and dynamics of absence seizures using the recorded data. It is worth mentioning that all previous studies have investigated absence seizures using the data recorded from different regions of the brain, while this is the first study that performs the local exploration of absence seizures using the data recorded from different layers of somatosensory cortex, i.e., the main starting region of absence seizures.Using factor analysis, source separation, and blind deconvolution methods in different scenarios, we show that 1) the top and bottom layers of somatosensory cortex activate more than the other layers during absence seizures, 2) there is a background epileptic activity during absence seizures, 3) there are few activities or states which randomly activate with the background epileptic activity to generate the absence seizures, and 4) one of these states is dominant, and the others are unstable.

Le doctorant n'a pas délivré de résumé en français

Mots clés: EEG analysis; Tensor Decomposition; Source Separataion

Mots clés: Analyser des electroencephalogrammes; Décomposition du tenseur; Séparation de source

Domaines: Traitement du signal et de l'image [eess.SP]

Saeed Akhavanbahabadi. Analysis of Absence Epileptic Seizures Using Depth Cortical Measurements. Signal and Image processing. Université Grenoble Alpes; University of Teheran, 2019. English. ⟨NNT : 2019GREAT063⟩. ⟨tel-02527359⟩