title: Fast Activity Evoked by Intracranial 50 Hz Electrical Stimulation as a Marker of the Epileptogenic Zone.
abstract: Epilepsy is a disease characterized by aberrant connections between brain areas. The altered activity patterns generated by epileptic networks can be analyzed with intracerebral electrodes during pre-surgical stereo-electroencephalographic (EEG) monitoring in patients candidate to epilepsy surgery. The responses to high frequency stimulation (HFS) at 50 Hz performed for diagnostic purposes during SEEG were analyzed with a new algorithm, to evaluate signal parameters that are masked to visual inspection and to define the boundaries of the epileptogenic network. The analysis was focused on 60-80 Hz activity that represented the largest frequency component evoked by HFS. The distribution of HFS-evoked fast activity across all (up to 162) recording contacts allowed to define different clusters of contacts that retrospectively correlated to the epileptogenic zone identified by the clinicians on the basis of traditional visual analysis. The study demonstrates that computer-assisted analysis of HFS-evoked activities may contribute to the definition of the epileptogenic network on intracranial recordings performed in a pre-surgical setting.
authors.affiliation: Unit of Epileptology and Experimental Neurophysiology, Fondazione IRCCS, Istituto Neurologico Carlo Besta, 20133 Milano, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bellistri
authors.affiliation: Claudio Munari Epilepsy Surgery Center, Ospedale, Niguarda Ca' Granda, Milano, Italy.
authors.forename: Ivana
authors.initials: I
authors.lastname: Sartori
authors.affiliation: Claudio Munari Epilepsy Surgery Center, Ospedale, Niguarda Ca' Granda, Milano, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Pelliccia
authors.affiliation: Claudio Munari Epilepsy Surgery Center, Ospedale, Niguarda Ca' Granda, Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Francione
authors.affiliation: Claudio Munari Epilepsy Surgery Center, Ospedale, Niguarda Ca' Granda, Milano, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cardinale
authors.affiliation: Unit of Epileptology and Experimental Neurophysiology, Fondazione IRCCS, Istituto Neurologico Carlo Besta, 20133 Milano, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: de Curtis
authors.affiliation: Unit of Epileptology and Experimental Neurophysiology, Fondazione IRCCS, Istituto Neurologico Carlo Besta, 20133 Milano, Italy.
authors.forename: Vadym
authors.initials: V
authors.lastname: Gnatkovsky
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001921:Brain / Q000503:physiopathology* / Q000601:surgery; D001931:Brain Mapping / Q000379:methods; D002675:Child, Preschool; D016000:Cluster Analysis; D046690:Deep Brain Stimulation / Q000379:methods*; D000069279:Drug Resistant Epilepsy / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D000069280:Electrocorticography / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D012815:Signal Processing, Computer-Assisted
keywords: Focal epilepsy; epilepsy surgery; high-frequency stimulation; intracerebral recordings; stereo-EEG