title: Awake craniotomy for aggressive resection of primary gliomas located in eloquent brain.
abstract: OBJECTIVE
  To determine with intraoperative neurologic and language examinations the maximal tumor resection achievable with acceptable postoperative neurologic dysfunction in patients undergoing awake stereotactic glial tumor resection in eloquent regions of the brain.
  
  
  METHODS
  Between October 1995 and December 2000, 65 patients underwent frameless stereotactic resection of glial tumors located in functioning tissue. During the resection, continuous examinations by a neurologist and speech pathologist were performed. The goal of surgery was to resect the maximum neurologically permissible tumor volume defined on preoperative T2 imaging. Tumor resection was stopped at the onset of neurologic dysfunction. Novel segmentation software was used to measure tumor cytoreduction based on pre- and postoperative magnetic resonance imaging. All patients underwent 3-month postoperative neurologic examinations to determine functional outcomes.
  
  
  RESULTS
  The cortical and subcortical white matter tracts at risk for injury were the left frontal operculum in 15 patients, the central lobule in 38, the insula in 11, and the left angular gyrus in 1. Thirty-four (52%) had a greater than 90% reduction in T2 signal postoperatively. In 26 patients thought to have low-grade tumors based on preoperative imaging, 12 proved to have grade 3 gliomas. Forty-eight patients (74%) developed intraoperative deficits; 34 (71%) recovered to a modified Rankin grade of 0 or 1 at 3 months postoperatively, 11 (23%) achieved a modified Rankin grade of 2, and 3 patients (6%) achieved a modified Rankin grade of 3 or 4 at 3-month follow-up. There was no operative mortality; 17 patients (26%) died from tumor progression during the follow-up period.
  
  
  CONCLUSIONS
  Combining frameless computer-guided stereotaxis with cortical stimulation and repetitive neurologic and language assessments facilitates tumor resection in functioning brain regions. Resecting tumor until the onset of neurologic deficits allows for a good functional recovery. Imaging software can objectively and accurately measure preoperative and postoperative tumor volumes.
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic, Rochester, Minn 55905, USA. meyer.fredric@mayo.edu
authors.forename: F B
authors.initials: FB
authors.lastname: Meyer
authors.forename: L M
authors.initials: LM
authors.lastname: Bates
authors.forename: S J
authors.initials: SJ
authors.lastname: Goerss
authors.forename: J A
authors.initials: JA
authors.lastname: Friedman
authors.forename: W L
authors.initials: WL
authors.lastname: Windschitl
authors.forename: J R
authors.initials: JR
authors.lastname: Duffy
authors.forename: W J
authors.initials: WJ
authors.lastname: Perkins
authors.forename: B P
authors.initials: BP
authors.lastname: O'Neill
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000175:diagnosis / Q000601:surgery*; D016292:Procedural Sedation / Q000379:methods*; D003399:Craniotomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007807:Language Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009367:Neoplasm Staging; D009460:Neurologic Examination; D013238:Stereotaxic Techniques; D016896:Treatment Outcome; D014851:Wakefulness