title: Seizures Outcome After Stereoelectroencephalography-Guided Thermocoagulations in Malformations of Cortical Development Poorly Accessible to Surgical Resection.
abstract: BACKGROUND
  Radiofrequency thermocoagulation (RFTC) guided by stereoelectroencephalography (SEEG) has proved to be a safe palliative method to reduce seizure frequency in patients with drug-resistant partial epilepsy. In malformation of cortical development (MCD), increasing the number of implanted electrodes over that needed for mapping of the epileptogenic zone could help to maximize RFTC efficiency.
  
  
  OBJECTIVE
  To evaluate the benefit of SEEG-guided RFTC in 14 patients suffering from drug-resistant epilepsy related to MCD located in functional cortical areas or in regions poorly accessible to surgery.
  
  
  METHODS
  Ten men and 4 women were treated by RFTC. Thermolesions were produced by applying a 50-V, 120-mA current for 10 to 30 seconds within the epileptogenic zone as identified by the SEEG investigation.
  
  
  RESULTS
  An average of 25.8 ± 17.5 thermolesions were made per procedure. The median follow-up after the procedure was 41.7 months. Sixty-four percent of the patients experienced a long-term decrease in seizure frequency of >50%, of whom 6 (43%) presented long-lasting freedom from seizure. When a focal low-voltage fast activity was present at seizure onset on SEEG recordings, 87.5% of patients were responders or seizure free. All of the patients in whom electric stimulation reproduced spontaneous seizures were responders.
  
  
  CONCLUSIONS
  Our results show the good benefit-risk ratio of the SEEG-guided procedure for patients suffering from MCD in whom surgery is risky. This study identifies 2 factors, focal low-voltage, high-frequency activity at seizure onset and lowered epileptogenic threshold in the coagulated area, that could be predictive of a favorable seizure outcome after RFTC.
authors.affiliation: *Service de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Bron, France; ‡Centre de Recherche en Neurosciences, INSERM U1028, CNRS 5292, UCBL-1, Lyon, France; §Service de Neurochirurgie Fonctionnelle, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, Bron, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Catenoix
authors.forename: François
authors.initials: F
authors.lastname: Mauguière
authors.forename: Alexandra
authors.initials: A
authors.lastname: Montavont
authors.forename: Philippe
authors.initials: P
authors.lastname: Ryvlin
authors.forename: Marc
authors.initials: M
authors.lastname: Guénot
authors.forename: Jean
authors.initials: J
authors.lastname: Isnard
mesh_terms: D000328:Adult; D000368:Aged; D004564:Electrocoagulation / Q000379:methods*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications / Q000601:surgery*; D008875:Middle Aged; D012306:Risk; D012640:Seizures / Q000209:etiology / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult