title: Clinical relevance of source location in frontal lobe epilepsy and prediction of postoperative long-term outcome.
abstract: OBJECTIVE
  To evaluate the value of magnetoencephalography (MEG) source localization in localization of epileptic activities and predicting surgical outcome in frontal lobe epilepsies (FLE).
  
  
  METHODS
  Forty-six patients with presurgical MEG evaluation and intractable FLE surgery (28 male patients) were analyzed retrospectively with a mean follow-up of 5 years. Dipole analysis was performed for MEG source imaging (MSI). The localization of dipole clusters in relation to the dominant hemisphere, lesions, resection cavity and functional cortex were analyzed. The predictive value of MSI in respect to clinical outcome with long-term postoperative follow up was evaluated.
  
  
  RESULTS
  Interictal focal epileptic activities were found in 82.6% (38/46) patients with monofocal activity 81.6% (31/38) and multifocal activities 18.4% (7/38). Seizure free rate was 47.9% at the mean follow-up of 5.0 ± 4.0 years (median 11.5, range 2-57). Seizure recurrence mainly occurred in the first 1 year after surgery. In the monofocal epileptic activity group, 58.1% (18/31) of the patients were seizure free, predicitng postoperative seizure freedom better than multifocal localization 0% (0/7) (p=0.028). Dipole clusters were completely resected in 70.9% of monofocal activity patients, which had higher seizure free rates compared to partial resection (p=0.002). In patients with surgery in the dominant hemisphere, seizure control was less likely (p=0.006).
  
  
  CONCLUSIONS
  MSI contributes to the clinical prediction of postoperative outcome in FLE patients. MSI may non-invasively disclose early epileptogenic lesions, pointing to a resectable lesion, and it then facilitates shortcut route of presurgical evaluation.
authors.affiliation: Department of Neurology, University Hospital Erlangen, Erlangen, Germany; Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China. Electronic address: mujie2010@foxmail.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Mu
authors.affiliation: Department of Neurology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rampp
authors.affiliation: Reference Center for Refractory Epilepsy, Ghent University Hospital, Ghent, Belgium.
authors.forename: Evelien
authors.initials: E
authors.lastname: Carrette
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Roessler
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Bjoern
authors.initials: B
authors.lastname: Sommer
authors.affiliation: Department of Neurology, University Hospital Magdeburg, Magdeburg, Germany.
authors.forename: Friedhelm Carl
authors.initials: FC
authors.lastname: Schmitt
authors.affiliation: Laboratoire de Cartographie Fonctionnelle du Cerveau, ULB-Hôpital Erasme & UNI-ULB Neuroscience Institute, Université libre de Bruxelles (ULB), Brussels, Belgium.
authors.forename: Xavier
authors.initials: X
authors.lastname: De Tiège
authors.affiliation: Department of Neurology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Hajo
authors.initials: H
authors.lastname: Hamer
authors.affiliation: Reference Center for Refractory Epilepsy, Ghent University Hospital, Ghent, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: Boon
authors.affiliation: Department of Neurology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Pauli
authors.affiliation: Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Ingmar
authors.initials: I
authors.lastname: Bluemcke
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Buchfelder
authors.affiliation: Department of Neurology, University Hospital Erlangen, Erlangen, Germany. Electronic address: Hermann.Stefan@uk-erlangen.de.
authors.forename: Hermann
authors.initials: H
authors.lastname: Stefan
mesh_terms: D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy / Q000379:methods*; D002648:Child; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000601:surgery*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
keywords: Focal cortical dysplasia; Frontal lobe epilepsy; Magnetoencephalography; Postoperative outcome; Seizure freedom