gms | German Medical Science

73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

29.05. - 01.06.2022, Köln

Remote effects of paired-pulse TMS reflect language network connectivity

Fernwirkungen von Doppelpuls-TMS als Surrogatparameter für die Konnektivität des Sprachnetzwerkes

Meeting Abstract

  • presenting/speaker Greta Sonström - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland
  • Ricardo Louçäo - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland
  • Elisa Kallioniemi - Kuopio University Hospital, Department of Neurophysiology, Kuopio, Finnland
  • Petro Julkunen - University of Eastern Finland, Department of Physics, Kuopio, Finnland
  • Charlotte Nettekoven - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland
  • Julia Pieczewski - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland
  • Volker Neuschmelting - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland
  • Christian Grefkes - Universitätsklinikum Köln, Klinik für Neurologie, Köln, Deutschland; Forschungszentrum Jülich, Institut für Kognitive Neurowissenschaften, Jülich, Deutschland
  • Roland Goldbrunner - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland
  • Kristina Jonas - Universität zu Köln, Humanwissenschaftliche Fakultät, Köln, Deutschland
  • Carolin Weiß-Lucas - Universitätsklinikum Köln, Zentrum für Neurochirurgie, Köln, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie. Köln, 29.05.-01.06.2022. Düsseldorf: German Medical Science GMS Publishing House; 2022. DocV068

doi: 10.3205/22dgnc073, urn:nbn:de:0183-22dgnc0730

Published: May 25, 2022

© 2022 Sonström 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: Cortical silent periods (cSPs; i.e., temporary silencing of ongoing electromyographic activity), induced by paired-pulse transcranial magnetic stimulation (pp-TMS), are a common measure of the excitability status of the motor cortex. We could previously show that pp-TMS applied during an overt language task can elicit cSPs in face/jaw muscles even outside cortical motor areas. Overall, a correlation between these cSPs with impaired task performance (i.e., naming) was observed, suggesting remote effects of pp-TMS on the speech network. We, therefore, hypothesized that there might be a direct structural connection between these language-associated areas and the primary motor cortex (M1).

Methods: pp-TMS and diffusion-weighted imaging data of nine right-handed volunteers (five males, median age: 30 years, range: 25-41 years) were analyzed. FSL and MRtrix were used for probabilistic tractography. The diffusion-weighted images were denoised and corrected for susceptibility, motion, and eddy-induced distortions. Then, model fitting by constrained spherical deconvolution (CSD) was performed. The stimulation sites at which pp-TMS (over the left hemisphere) elicited cSPs in facial muscles were chosen as starting regions of interest (ROIs) for tractography. M1 was defined as the target ROI. Resulting tracts were identified according to a standard white matter atlas template.

Results: From every brain region where cSPs occured, fibres followed tracts which are known to connect to the motor cortex. TMS sites located in the temporal lobe were, i.a., associated with M1 via the arcuate fasciculus. The superior longitudinal fascicle (SLF) 3 connected seed points in the frontal lobe to M1. Originating from the supplementary motor cortex, U-shaped fibres reached the M1. The ROIs located in the parietal lobe were connected to M1 via the SLF.

Conclusion: The results support our hypothesis of remote pp-TMS effects on the speech-related primary motor system (i.e., face and jaw muscles). Despite limitations inherent to virtual dissection methods, our data drive the assumption that cSP could qualify as a marker to measure TMS-induced interference with cortical functioning even beyond the (primary) motor cortex.