gms | German Medical Science

63rd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Japanese Neurosurgical Society (JNS)

German Society of Neurosurgery (DGNC)

13 - 16 June 2012, Leipzig

Motor cortex plasticity in brain tumor patients

Meeting Abstract

  • M.T. Forster - Klinik für Neurochirurgie, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt/Main
  • C. Senft - Klinik für Neurochirurgie, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt/Main
  • E. Hattingen - Klinik für Neuroradiologie, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt/Main
  • M. Lorei - Klinik für Neuroradiologie, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt/Main
  • V. Seifert - Klinik für Neurochirurgie, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt/Main
  • A. Szelényi - Klinik für Neurochirurgie, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt/Main

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS). Leipzig, 13.-16.06.2012. Düsseldorf: German Medical Science GMS Publishing House; 2012. DocDO.11.08

doi: 10.3205/12dgnc106, urn:nbn:de:0183-12dgnc1069

Published: June 4, 2012

© 2012 Forster et al.
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Outline

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Objective: Although reorganization of cerebral function networks has been largely discussed during the past decade, only few reports on brain plasticity in brain tumor surgery have been made. We therefore aimed to investigate cerebral reorganization in patients operated on WHO grade II and III gliomas in or adjacent to the motor cortex by navigated transcranial magnetic stimulation (nTMS), thereby assessing the usefulness of this non-invasive brain mapping method.

Methods: Five patients were examined preoperatively as well as after a follow-up period of 17.7 ± 6.8 months. As a control, five healthy age-matched subjects were equally studied by nTMS in two sessions, spaced 12.6 (range 2–35) days apart. Resting motor thresholds (RMT), hotspots and centers of gravity (CoG) were identified for first dorsal interosseous (ID1), abductor pollicis brevis (APB), extensor digitorum (ED), tibialis anterior (TA) and abductor hallucis (AH) muscles.

Results: Participants showed moderate to excellent reliability measurement of the RMT (ICC = 0.69–0.94). Average movement of their CoGs across sessions was 0.68 ± 0.34 cm in the dominant and 0.76 ± 0.38 cm in the non-dominant hemisphere, whereas their hotspots experienced mean displacements by 0.87 ± 0.51 cm and 0.82 ± 0.45 cm, respectively. Movement was more important along the x- than the y-axis for both CoGs and hotspots, confirmed by coefficients of variance ranging from 12.61% to 54.51% and from 4.64% to 8.53%, accordingly.

In one patient these parameters differed unambiguously from the control group, presenting an average shift of CoGs by 1.94 ± 0.34 cm and of hotspots by 2.02 ± 0.49 cm between sessions (p < 0.05 for both CoG and hotspots when compared to the corresponding average movement across all healthy subjects and both sessions). Overall, patients' CoGs moved 1.12 ± 0.93 cm, whereas hotspots lay 1.06 ± 0.7 cm apart. Again, assessed parameters experienced displacement mainly in the lateral direction.

Conclusions: By this study we propose a new method for evaluating cortical reorganization using nTMS. In brain tumor surgery this procedure may contribute to the understanding of cerebral dynamics, thus influencing surgical decisions.