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71. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
9. Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

21.06. - 24.06.2020

Disturbed beta synchronisation after transcranial magnetic stimulation in chronic stroke

Gestörte Synchronisation der sensomotorischen β-Oszillationen nach transkranieller Magnetstimulation bei chronischen Schlaganfallpatienten

Meeting Abstract

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  • presenting/speaker Georgios Naros - Eberhard Karls Universität Tübingen, Klinik für Neurochirurgie, Tübingen, Deutschland
  • Bettina Trunk - Eberhard Karls Universität Tübingen, Klinik für Neurochirurgie, Tübingen, Deutschland
  • Alireza Gharabaghi - Eberhard Karls Universität Tübingen, Klinik für Neurochirurgie, Tübingen, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 71. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 9. Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. sine loco [digital], 21.-24.06.2020. Düsseldorf: German Medical Science GMS Publishing House; 2020. DocP227

doi: 10.3205/20dgnc513, urn:nbn:de:0183-20dgnc5134

Published: June 26, 2020

© 2020 Naros 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: The combination of neurostimulation (i.e. transcranial magnetic stimulation) and neuroimaging (i.e. electroencephalography, EEG) enables insights in the cortical physiology after brain damage, such as stroke. However, the available data is sparse. In the present study, we applied TMS-EEG to probe cortico-cortical integrity in 17 severely affected chronic stroke patients as well as in ten healthy age-matched controls. Electrophysiological findings were compared to clinical outcome measures and lesion characteristics

Methods: For this purpose, we applied magnetic pulses over both the affected and the unaffected hemisphere of severely-affected stroke patients while concomitantly recording electroencephalographic (TMS-EEG) signal. Subsequently data was analyzed evaluating the time-locked brain response in the timeseries and frequency domain. TMS-EEG experiment was repeated on both hemispheres of ten age-matched healthy subjects.

Results: In the stroke patients, magnetic stimulation of the unaffected hemisphere leads to an early (0-100 ms) and late (250-300 ms after TMS) synchronization in the beta frequencies. This behavior was significantly attenuated over the affected hemisphere. While the reduction of the early beta synchronization was related to the involvement of motor cortex, late beta synchronization was conserved in patients with contralesional upper limb MEPs. There was no correlation between the TMS-EEG findings and lesion size. Finally, there were no hemispheric differences in age-matched healthy subjects.

Conclusion: We conclude that early beta synchronization after TMS might serve as a biomarker for cortico-cortical integrity while late beta synchronization might indicate cortico-spinal integrity. In severe chronic stroke the motor network fails to restore the physiological motor frequencies indicating a massive cortical dysfunction. TMS-EEG recordings could be used in future to evaluate cortico-cortical integrity before and after neurosurgical interventions.