title: Intra- and interobserver variability of language mapping by navigated transcranial magnetic brain stimulation.
abstract: BACKGROUND
  Repetitive navigated transcranial magnetic stimulation (rTMS) has been used for studying language organization in healthy volunteers and patients, and to detect cortical areas involved in language processing. However, little is known about the reliability of this method. To determine the reliability of rTMS language mapping, we conducted both an interobserver and an intraobserver investigation.
  
  
  METHODS
  Ten right-handed healthy subjects underwent language mapping by rTMS and the same object-naming task three times. Intraobserver and interobserver reliability of seven different error types were tested by two investigators. Analysis was performed blinded to the previous results and stimulated cortical sites.
  
  
  RESULTS
  Overall, the results of both the interobserver and the intraobserver investigations show variable accordance. This is demonstrated by comparing the error rates of all different error types of the three examinations. Considering the most important error type, "no response", there is only small variability in inter- and intraobserver mapping.
  
  
  CONCLUSIONS
  With our current protocol, interobserver and intraobserver comparisons only corresponded partially. Thus, although rTMS seems a promising method for preoperative planning as well as neuropsychological research, the current protocol needs further improvement.
authors.affiliation: Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str, 22, 81675 Munich, Germany. Sandro.Krieg@lrz.tum.de.
authors.forename: Nico
authors.initials: N
authors.lastname: Sollmann
authors.forename: Theresa
authors.initials: T
authors.lastname: Hauck
authors.forename: Alexander
authors.initials: A
authors.lastname: Hapfelmeier
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meyer
authors.forename: Florian
authors.initials: F
authors.lastname: Ringel
authors.forename: Sandro M
authors.initials: SM
authors.lastname: Krieg
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007802:Language; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult