gms | German Medical Science

63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

13. - 16. Juni 2012, Leipzig

Test/retest variability of navigated transcranial magnetic stimulation in healthy subjects and brain tumor patients

Meeting Abstract

  • A. Zdunczyk - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland
  • R. Fleischmann - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland
  • J. Schulz - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland
  • T. Picht - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland
  • P. Vajkoczy - Klinik für Neurochirurgie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland

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.11.02

doi: 10.3205/12dgnc100, urn:nbn:de:0183-12dgnc1008

Veröffentlicht: 4. Juni 2012

© 2012 Zdunczyk et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: Navigated transcranial magnetic stimulation (nTMS) is an emerging method used routinely for presurgical motor mapping. Its excellent correlation with direct cortical stimulation has been demonstrated before. In order to further evaluate the reliability of the method we set out to analyze the test retest reliability.

Methods: The primary motor cortex of 10 healthy subjects was mapped with nTMS by two investigators with different hands-on experience (beginner, expert). After 2 weeks the examination was repeated in an identical manner. In an analogous way 10 patients with distorted anatomy of the central region due to expansive glioma growth were mapped preoperatively. For each session the resting motor threshold, hotspot and center of gravity were determined individually. Statistical testing was performed in order to compare the two groups with respect to inter and intra-examiner variability.

Results: Both analyses revealed a high reliability in the two groups. Center of gravity was the parameter that showed the highest consistency. The mean ± SEM inter-examiner variability was 4,64 ± 0,57 mm in healthy subjects. In the same group, analyzing the retest session for the expert investigator revealed an intra-examiner variability of 3,82 ± 0,54 mm. The assessment of the center of gravity in the patient group showed a mean ± SEM difference of 5,82 ± 0,82 mm between the two investigators. Quality of EMG recording and mapping area size had a significant impact on the variability.a mean ± SEM difference of 5,82 ± 0,82 mm between the two investigators. Quality of EMG recording and mapping area size had a significant impact on the variability.

Conclusions: The assessment of nTMS test retest variability demonstrated a high degree of consistency irregardless of the examiner's experience. Inconsistency can be caused by low EMG quality and may also reflect the actual complex somatotopy of the primary motor cortex.