gms | German Medical Science

67th Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Korean Neurosurgical Society (KNS)

German Society of Neurosurgery (DGNC)

12 - 15 June 2016, Frankfurt am Main

Language function distribution in left-handers: a navigated transcranial magnetic stimulation study

Meeting Abstract

  • Nico Sollmann - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Germany
  • Lorena Tussis - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Germany
  • Tobias Boeckh-Behrens - Abteilung für Diagnostische und Interventionelle Neuroradiologie, Klinikum rechts der Isar, Technische Universität München, Germany
  • Bernhard Meyer - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Germany
  • Sandro M. Krieg - Neurochirurgische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Germany

Deutsche Gesellschaft für Neurochirurgie. 67. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 1. Joint Meeting mit der Koreanischen Gesellschaft für Neurochirurgie (KNS). Frankfurt am Main, 12.-15.06.2016. Düsseldorf: German Medical Science GMS Publishing House; 2016. DocMI.15.09

doi: 10.3205/16dgnc327, urn:nbn:de:0183-16dgnc3276

Published: June 8, 2016

© 2016 Sollmann et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objective: Recent studies suggest that in left-handers, the right hemisphere (RH) is more involved in language function when compared to right-handers. Since data on lesion-based approaches is lacking, we aimed to investigate language distribution of left-handers by repetitive navigated transcranial magnetic stimulation (rTMS).

Method: rTMS was applied to both hemispheres in fifteen healthy left-handers during an object-naming task, and resulting naming errors were categorized. Then we calculated error rates (ER = number of errors per number of stimulations) and defined the hemispheric dominance ratio (HDR) as the quotient of the left- through the right-sided ER (HDR > 1 = left dominant; HDR < 1 = right dominant).

Results: No significant difference in ERs was found between the RH and left hemisphere (LH) (all errors: mean LH 18.0 ± 11.7%, mean RH 18.1 ± 12.2%, p=0.94; all errors without hesitation: mean LH 12.4 ± 9.8%, mean RH 12.9 ± 10.0%, p=0.67; no responses: mean LH 9.3 ± 9.3%, mean RH 11.5 ± 10.2%, p=0.91). However, left-handers present a lower HDR compared to right-handers (source data of another study) for all errors and all errors without hesitation (all errors: mean 1.1 ± 0.3 vs. 1.8 ± 0.8, p=0.0001; all errors without hesitation: mean 1.0 ± 0.4 vs. 1.8 ± 1.0, p=0.0008), but not for no-response errors (mean: 1.1 ± 0.9 vs. 1.5 ± 1.5, p= 0.78).

Conclusions: According to our rTMS approach, left-handers present a comparatively homogeneous language distribution across the LH and RH with language dominance being nearly equally distributed between hemispheres in contrast to right-handers.