title: Seizure-onset patterns in focal cortical dysplasia and neurodevelopmental tumors: Relationship with surgical prognosis and neuropathologic subtypes.
abstract: The study of intracerebral electroencephalography (EEG) seizure-onset patterns is crucial to accurately define the epileptogenic zone and guide successful surgical resection. It also raises important pathophysiologic issues concerning mechanisms of seizure generation. Until now, several seizure-onset patterns have been described using distinct recording methods (subdural, depth electrode), mostly in temporal lobe epilepsies or with heterogeneous neocortical lesions.
  
  
  
  We analyzed data from a cohort of 53 consecutive patients explored by stereoelectroencephalography (SEEG) and with pathologically confirmed malformation of cortical development (MCD; including focal cortical dysplasia [FCD] and neurodevelopmental tumors [NDTs]).
  
  
  
  We identified six seizure-onset patterns using visual and time-frequency analysis: low-voltage fast activity (LVFA); preictal spiking followed by LVFA; burst of polyspikes followed by LVFA; slow wave/DC shift followed by LVFA; theta/alpha sharp waves; and rhythmic spikes/spike-waves. We found a high prevalence of patterns that included LVFA (83%), indicating nevertheless that LVFA is not a constant characteristic of seizure onset. An association between seizure-onset patterns and histologic types was found (p = 001). The more prevalent patterns were as follows: (1) in FCD type I LVFA (23.1%) and slow wave/baseline shift followed by LVFA (15.4%); (2) in FCD type II burst of polyspikes followed by LVFA (31%), LVFA (27.6%), and preictal spiking followed by LVFA (27.6%); (3) in NDT, LVFA (54.5%). We found that a seizure-onset pattern that included LVFA was associated with favorable postsurgical outcome, but the completeness of the EZ resection was the sole independent predictive variable.
  
  
  
  Six different seizure-onset patterns can be described in FCD and NDT. Better postsurgical outcome is associated with patterns that incorporate LVFA.
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Lagarde
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bonini
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Aileen
authors.initials: A
authors.lastname: McGonigal
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Chauvel
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Gavaret
authors.affiliation: Department of Pediatric Neurosurgery, APHM, Timone Hospital, Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Scavarda
authors.affiliation: Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.|Department of Functional and Stereotactic Neurosurgery, APHM, Timone Hospital, Marseille, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Carron
authors.affiliation: Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.|Department of Functional and Stereotactic Neurosurgery, APHM, Timone Hospital, Marseille, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Régis
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Aubert
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Villeneuve
authors.affiliation: Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Giusiano
authors.affiliation: Department of Anatomopathology, APHM, Timone Hospital, Marseille, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Figarella-Branger
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Trebuchon
authors.affiliation: Clinical Neurophysiology and Epileptology Department, APHM, Timone Hospital, Marseille, France.|Inserm, Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bartolomei
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D058256:Brain Waves / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004569:Electroencephalography; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D054220:Malformations of Cortical Development / Q000145:classification / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D012640:Seizures / Q000175:diagnosis* / Q000209:etiology*; D018709:Statistics, Nonparametric; D015898:Tomography Scanners, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
keywords: Epilepsy; Epilepsy surgery; Epileptogenic zone; Focal cortical dysplasia; Malformation of cortical development; Neurodevelopmental tumors; Seizure onset; Stereoelectroencephalography