title: Usefulness of intraoperative electrical subcortical mapping during surgery for low-grade gliomas located within eloquent brain regions: functional results in a consecutive series of 103 patients.
abstract: OBJECTIVE
  Although a growing number of authors currently advocate surgery to treat low-grade gliomas, controversy still persists, especially because of the risk of inducing neurological sequelae when the tumor is located within eloquent brain areas. Many researchers performing preoperative neurofunctional imaging and intraoperative electrophysiological methods have recently reported on the usefulness of cortical functional mapping. Despite the frequent involvement of subcortical structures by these gliomas, very few investigators have specifically raised the subject of fiber tracking. The authors in this report describe the importance of mapping cortical and subcortical functional regions by using intraoperative real-time direct electrical stimulations during resection of low-grade gliomas.
  
  
  METHODS
  Between 1996 and 2001, 103 patients harboring a corticosubcortical low-grade glioma in an eloquent area, with no or only mild deficit, had undergone surgery during which intraoperative electrical mapping of functional cortical sites and subcortical pathways was performed throughout the procedure. Both eloquent cortical areas and corresponding white fibers were systematically detected and preserved, thus defining the resection boundaries. Despite an 80% rate of immediate postoperative neurological worsening, 94% of patients recovered their preoperative status within 3 months--10% even improved--and then returned to a normal socioprofessional life. Eighty percent of resections were classified as total or subtotal based on control magnetic resonance images.
  
  
  CONCLUSIONS
  The use of functional mapping of the white matter together with cortical mapping allowed the authors to optimize the benefit/risk ratio of surgery of low-grade glioma invading eloquent regions. Given that preoperative fiber tracking with the aid of neuroimaging is not yet validated, we used intraoperative real-time cortical and subcortical stimulations as a valuable adjunct to the other mapping methods.
authors.affiliation: Department of Neurosurgery, Hôpital de la Salpétrière, Paris, France. hugues.duffau@psl.ap-hop-paris.fr
authors.forename: Hugues
authors.initials: H
authors.lastname: Duffau
authors.forename: Laurent
authors.initials: L
authors.lastname: Capelle
authors.forename: Dominique
authors.initials: D
authors.lastname: Denvil
authors.forename: Nicole
authors.initials: N
authors.lastname: Sichez
authors.forename: Peggy
authors.initials: P
authors.lastname: Gatignol
authors.forename: Luc
authors.initials: L
authors.lastname: Taillandier
authors.forename: Manuel
authors.initials: M
authors.lastname: Lopes
authors.forename: Mary-Christine
authors.initials: MC
authors.lastname: Mitchell
authors.forename: Sabine
authors.initials: S
authors.lastname: Roche
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Muller
authors.forename: Ahmad
authors.initials: A
authors.lastname: Bitar
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Sichez
authors.forename: Rémy
authors.initials: R
authors.lastname: van Effenterre
mesh_terms: D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000150:complications / Q000473:pathology / Q000601:surgery; D004558:Electric Stimulation / Q000295:instrumentation; D005260:Female; D005910:Glioma / Q000150:complications / Q000473:pathology / Q000601:surgery; D006801:Humans; D007430:Intraoperative Care; D007806:Language Disorders / Q000175:diagnosis / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000473:pathology; D019635:Neurosurgical Procedures / Q000295:instrumentation*; D011300:Preoperative Care; D012189:Retrospective Studies; D012720:Severity of Illness Index