title: Occipital and occipital "plus" epilepsies: A study of involved epileptogenic networks through SEEG quantification.
abstract: Compared with temporal or frontal lobe epilepsies, the occipital lobe epilepsies (OLE) remain poorly characterized. In this study, we aimed at classifying the ictal networks involving OLE and investigated clinical features of the OLE network subtypes. We studied 194 seizures from 29 consecutive patients presenting with OLE and investigated by stereoelectroencephalography (SEEG). Epileptogenicity of occipital and extraoccipital regions was quantified according to the 'epileptogenicity index' (EI) method. We found that 79% of patients showed widespread epileptogenic zone organization, involving parietal or temporal regions in addition to the occipital lobe. Two main groups of epileptogenic zone organization within occipital lobe seizures were identified: a pure occipital group and an occipital "plus" group, the latter including two further subgroups, occipitotemporal and occipitoparietal. In 29% of patients, the epileptogenic zone was found to have a bilateral organization. The most epileptogenic structure was the fusiform gyrus (mean EI: 0.53). Surgery was proposed in 18/29 patients, leading to seizure freedom in 55% (Engel Class I). Results suggest that, in patient candidates for surgery, the majority of cases are characterized by complex organization of the EZ, corresponding to the occipital plus group.
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Angela
authors.initials: A
authors.lastname: Marchi
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bonini
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Lagarde
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Aileen
authors.initials: A
authors.lastname: McGonigal
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Gavaret
authors.affiliation: APHM, Timone Hospital, Paediatric Neurosurgery Department, Marseille 13005, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Scavarda
authors.affiliation: APHM, Timone Hospital, Functional and Stereotactical Neurosurgery Department, Marseille 13005, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Carron
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Aubert
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Villeneuve
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France.
authors.forename: Samuel
authors.initials: S
authors.lastname: Médina Villalon
authors.affiliation: Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Bénar
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France.
authors.forename: Agnes
authors.initials: A
authors.lastname: Trebuchon
authors.affiliation: APHM, Timone Hospital, Clinical Neurophysiology and Epileptology Department, Marseille 13005, France; Aix-Marseille Université, Institut de Neuroscience des Systèmes, UMR_S 1106, Marseille 13005, France. Electronic address: fabrice.bartolomei@ap-hm.fr.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bartolomei
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004569:Electroencephalography / Q000379:methods*; D004828:Epilepsies, Partial / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D009778:Occipital Lobe / Q000503:physiopathology* / Q000601:surgery; D013702:Temporal Lobe / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult
keywords: Epilepsy surgery; Epileptogenicity index; Focal epilepsy; Occipital lobe