title: Preoperative language mapping by repetitive navigated transcranial magnetic stimulation and diffusion tensor imaging fiber tracking and their comparison to intraoperative stimulation.
abstract: BACKGROUND
  Repetitive navigated transcranial magnetic stimulation (rTMS) can be used for preoperative language mapping, but it still suffers from comparatively high sensitivity and low specificity when compared to direct cortical stimulation (DCS). Therefore, this study evaluates whether the additional consideration of rTMS-based diffusion tensor imaging fiber tracking (DTI FT) for identifying language-positive brain regions improves specificity when compared to DCS.
  
  
  METHODS
  We performed rTMS, rTMS-based DTI FT, and DCS during awake surgery combined with object naming in 20 patients suffering from left-sided perisylvian brain lesions. For rTMS, different error rate thresholds (ERTs) and error types were considered, and DTI FT was conducted with individualized fractional anisotropy thresholds (FATs). Then, receiver operating characteristics (ROC) for rTMS vs. DCS, rTMS-based DTI FT vs. DCS, and rTMS spots confirmed by rTMS-based DTI FT vs. DCS were calculated.
  
  
  RESULTS
  In general, rTMS vs. DCS was in good accordance with previous literature (sensitivity/specificity: 92.7/13.3 % for all naming errors without ERT). In addition, rTMS-based DTI FT vs. DCS led to balanced results when tracking was based on all errors as well (sensitivity/specificity: 62.8/64.3 % for 100 % FAT). However, rTMS combined with rTMS-based DTI FT vs. DCS did not lead to any improvement in specificity when compared to rTMS vs. DCS alone.
  
  
  CONCLUSIONS
  The additional use of rTMS-based DTI FT to rTMS did not improve the identification of DCS-positive language areas during awake surgery. Yet, concerning rTMS-based DTI FT, this new technique must be validated itself by intraoperative subcortical stimulation.
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.|TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Sollmann
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.
authors.forename: Antonia
authors.initials: A
authors.lastname: Kubitscheck
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.|TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Maurer
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.|TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ille
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.|TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Hauck
authors.affiliation: Section of Neuroradiology, Department of Radiology, Klinikum rechts der Isar, Technische Universität München, München, Germany.
authors.forename: Jan S
authors.initials: JS
authors.lastname: Kirschke
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Ringel
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meyer
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, München, 81675, Germany. sandro.krieg@tum.de.|TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, München, Germany. sandro.krieg@tum.de.
authors.forename: Sandro M
authors.initials: SM
authors.lastname: Krieg
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D002648:Child; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D007802:Language; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology; D011300:Preoperative Care / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Diffusion tensor imaging; Direct cortical stimulation; Fiber tracking; Language; Navigated transcranial magnetic stimulation