title: Impairment of preoperative language mapping by lesion location: a functional magnetic resonance imaging, navigated transcranial magnetic stimulation, and direct cortical stimulation study.
abstract: OBJECTIVE
  Language mapping by repetitive navigated transcranial magnetic stimulation (rTMS) is increasingly used and has already replaced functional MRI (fMRI) in some institutions for preoperative mapping of neurosurgical patients. Yet some factors affect the concordance of both methods with direct cortical stimulation (DCS), most likely by lesions affecting cortical oxygenation levels. Therefore, the impairment of the accuracy of rTMS and fMRI was analyzed and compared with DCS during awake surgery in patients with intraparenchymal lesions.
  
  
  METHODS
  Language mapping was performed by DCS, rTMS, and fMRI using an object-naming task in 27 patients with left-sided perisylvian lesions, and the induced language errors of each method were assigned to the cortical parcellation system. Subsequently, the receiver operating characteristics were calculated for rTMS and fMRI and compared with DCS as ground truth for regions with (w/) and without (w/o) the lesion in the mapped regions.
  
  
  RESULTS
  The w/ subgroup revealed a sensitivity of 100% (w/o 100%), a specificity of 8% (w/o 5%), a positive predictive value of 34% (w/o: 53%), and a negative predictive value (NPV) of 100% (w/o: 100%) for the comparison of rTMS versus DCS. Findings for the comparison of fMRI versus DCS within the w/ subgroup revealed a sensitivity of 32% (w/o: 62%), a specificity of 88% (w/o: 60%), a positive predictive value of 56% (w/o: 62%), and a NPV of 73% (w/o: 60%).
  
  
  CONCLUSIONS
  Although strengths and weaknesses exist for both rTMS and fMRI, the results show that rTMS is less affected by a brain lesion than fMRI, especially when performing mapping of language-negative cortical regions based on sensitivity and NPV.
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ille
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Nico
authors.initials: N
authors.lastname: Sollmann
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Theresa
authors.initials: T
authors.lastname: Hauck
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Maurer
authors.affiliation: Faculty of Linguistics, Philology, & Phonetics, University of Oxford, Oxford, United Kingdom.
authors.forename: Noriko
authors.initials: N
authors.lastname: Tanigawa
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Thomas
authors.initials: T
authors.lastname: Obermueller
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Chiara
authors.initials: C
authors.lastname: Negwer
authors.affiliation: Department of Anesthesiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; and.
authors.forename: Doris
authors.initials: D
authors.lastname: Droese
authors.affiliation: Section of Neuroradiology, Department of Radiology, and.
authors.forename: Tobias
authors.initials: T
authors.lastname: Boeckh-Behrens
authors.affiliation: Department of Neurosurgery.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meyer
authors.affiliation: Department of Neurosurgery.
authors.forename: Florian
authors.initials: F
authors.lastname: Ringel
authors.affiliation: Department of Neurosurgery.|TUM-Neuroimaging Center.
authors.forename: Sandro M
authors.initials: SM
authors.lastname: Krieg
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D002540:Cerebral Cortex / Q000473:pathology / Q000601:surgery*; D003399:Craniotomy; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
keywords: BOLD = blood-oxygen-level dependent; CPS = cortical parcellation system; DCS = direct cortical stimulation; DTI-FT = diffusion tensor imaging fiber tracking; NPV = negative predictive value; PPV = positive predictive value; PTI = picture-to-trigger interval; RMT = resting motor threshold; ROC = receiver operating characteristic; TMS = transcranial magnetic stimulation; awake surgery; diagnostic and operative techniques; fMRI = functional MRI; functional magnetic resonance imaging; language; rTMS = repetitive navigated TMS; transcranial magnetic stimulation; tumor