title: Beyond the lesion: the epileptogenic networks around cavernous angiomas.
abstract: The relationship between epileptogenic lesions and the extension of epileptogenicity is a major challenge in presurgical evaluation of drug resistant epilepsies. In this study, we aimed at quantifying the epileptogenic properties of brain structures explored by depth electrodes in patients investigated by stereoelectroencephalography (SEEG) and suffering from focal drug-resistant epilepsy associated with cavernous angioma (CA). Epileptogenicity of the perilesional region and distant brain areas was calculated according to the "epileptogenicity index" (EI), a technique that allows mathematical quantification of rapid discharges at seizure onset taking into account the time at which the discharge occurs. Thirteen seizures from 6 patients were studied. Localization of the cavernoma was the frontal lobe (two cases), the temporal lobe (three cases) or the anterior insula (one case). Visual inspection of the ictal discharge showed that in the majority of cases (5/6) the perilesional region was either not involved or involved with other distant sites. Using EI quantification, complex patterns of epileptogenicity were observed in five patients. A large number of brain regions out of the lesional region disclosed higher values than the lesion site. Mean values in the perilesional region and in the extralesional sites were not significantly different (p=0.34). Complex organization of the epileptogenic zone may be found in drug-resistant CA associated epilepsy. Thus, this result should be borne in mind when patients with CA and drug resistant epilepsy are investigated. If there is a suspicion of a larger epileptogenic zone than the lesion, intra-cerebral exploration by SEEG may be required before surgery that may be guided by the definition of the EZ.
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Sevy
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France; INSERM, U1106, Marseille F-13005, France; Aix Marseille Université, Faculté de Médecine, Marseille F-13005, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Gavaret
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France; INSERM, U1106, Marseille F-13005, France; Aix Marseille Université, Faculté de Médecine, Marseille F-13005, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Trebuchon
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France; INSERM, U1106, Marseille F-13005, France; Aix Marseille Université, Faculté de Médecine, Marseille F-13005, France.
authors.forename: Lisa
authors.initials: L
authors.lastname: Vaugier
authors.affiliation: INSERM, U1099, Université Rennes 1, Rennes, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Wendling
authors.affiliation: Service de Neurochirurgie fonctionnelle et Stéréotaxie, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Carron
authors.affiliation: Service de Neurochirurgie fonctionnelle et Stéréotaxie, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Regis
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France; INSERM, U1106, Marseille F-13005, France; Aix Marseille Université, Faculté de Médecine, Marseille F-13005, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Chauvel
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France; INSERM, U1106, Marseille F-13005, France; Aix Marseille Université, Faculté de Médecine, Marseille F-13005, France.
authors.forename: Aileen Mc
authors.initials: AM
authors.lastname: Gonigal
authors.affiliation: CHU Timone, Service de Neurophysiologie Clinique, Assistance Publique des Hôpitaux de Marseille, Marseille F-13005, France; INSERM, U1106, Marseille F-13005, France; Aix Marseille Université, Faculté de Médecine, Marseille F-13005, France. Electronic address: fabrice.bartolomei@ap-hm.fr.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bartolomei
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000150:complications / Q000503:physiopathology*; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D020786:Hemangioma, Cavernous, Central Nervous System / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology*; D055815:Young Adult
keywords: Cavernous angioma; Epileptogenicity index; Partial epilepsy; SEEG