title: Source reconstruction based on subdural EEG recordings adds to the presurgical evaluation in refractory frontal lobe epilepsy.
abstract: OBJECTIVE
  In presurgical investigations of refractory frontal lobe epilepsy, subdural EEG recordings offer extensive cortical coverage, but may overlook deep sources. Electrical Source Localization (ESL) from subdural recordings could overcome this sampling limitation. This study aims to assess the clinical relevance of this new method in refractory frontal lobe epilepsy associated with focal cortical dysplasia.
  
  
  METHODS
  In 14 consecutive patients, we retrospectively compared: (i) the ESL of interictal spikes to the conventional irritative and seizure onset zones; (ii) the surgical outcome of cases with congruent ESL and resection volume to cases with incongruent ESL and resection volume. Each spike type was averaged to serve as a template for ESL by the MUSIC and sLORETA algorithms. Results were superimposed on the corresponding pre and post-surgical MRI.
  
  
  RESULTS
  Both ESL methods were congruent and consistent with conventional electroclinical analysis in all patients. In 7 cases, ESL identified a common deep source for spikes of different 2D localizations. The inclusion of ESL in the resection volume correlated with seizure freedom.
  
  
  CONCLUSIONS
  ESL from subdural recordings provided clinically relevant results in patients with refractory frontal lobe epilepsy.
  
  
  CONCLUSIONS
  ESL complements the conventional analysis of subdural recordings. Its potential in improving tailored resections and surgical outcomes should be prospectively assessed.
authors.affiliation: Epilepsy Center, University of Freiburg, Breisacher Str. 64, 79106 Freiburg, Germany. georgia.ramantani@uniklinik-freiburg.de
authors.forename: Georgia
authors.initials: G
authors.lastname: Ramantani
authors.forename: Delphine
authors.initials: D
authors.lastname: Cosandier-Rimélé
authors.forename: Andreas
authors.initials: A
authors.lastname: Schulze-Bonhage
authors.forename: Louis
authors.initials: L
authors.lastname: Maillard
authors.forename: Josef
authors.initials: J
authors.lastname: Zentner
authors.forename: Matthias
authors.initials: M
authors.lastname: Dümpelmann
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D057234:Preoperative Period; D013355:Subdural Space; D016896:Treatment Outcome