gms | German Medical Science

55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

25. bis 28.04.2004, Köln

Multimodal intraoperative neurophysiological monitoring during spinal surgery

Multimodales neurophysiologisches Monitoring bei spinalen Eingriffen

Meeting Abstract

Suche in Medline nach

  • corresponding author Theodoros Kombos - Neurochirurgische Klinik , Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin
  • O. Süss - Neurochirurgische Klinik , Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin
  • M. Brock - Neurochirurgische Klinik , Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin

Deutsche Gesellschaft für Neurochirurgie. Ungarische Gesellschaft für Neurochirurgie. 55. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 1. Joint Meeting mit der Ungarischen Gesellschaft für Neurochirurgie. Köln, 25.-28.04.2004. Düsseldorf, Köln: German Medical Science; 2004. DocDI.02.10

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2004/04dgnc0164.shtml

Veröffentlicht: 23. April 2004

© 2004 Kombos 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 vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective

Intraoperative monitoring of somatosensory evoked potentials (SEP) has been mainly applied to spinal operations such as stabilization after trauma, resection of spinal tumors and scoliosis surgery. However little experience exists with intraoperative motor evoked potentials (MEP) during spinal surgery. This prospective study combines MEP and SEP in a protocol for intraoperative monitoring of the spinal cord functional systems. The protocol was evaluated according to its safety and sensitivity for clinical relevant potential alterations.

Methods

In this prospective study, 53 patients were examined intraoperatively according to a standardized electrophysiological protocol. SEPs were generated by stimulation of the median (n= 25) or tibial (n= 28) nerve bilaterally. MEPs were elicited by a transcranial high-frequency (500 Hz; Train of 3 impulses) electrical stimulation (HFTS) of the motor cortex. Stimulation intensity varied between 41,6 and 100 mA. Subdermal needle electrodes placed in the thenar, forearm flexor, quadriceps and tibial muscles were used for recording. Anesthesia was performed without neuromuscular blocking agents.

Results

Intraoperative SEP recording was possible in 50 patients (94.3%). MEPs were elicited following HFTS in 48 cases (90.6%). In 5 cases no MEP was recorded, not even after maximal stimulation intensity, however SEPs were recordable. On the other hand, HFTS elicited MEPS in 2 cases with no recordable SEPs. Thus, combining SEP-PR and MCS allowed intraoperative localization of the sensorimotor cortex in 98.1% of the cases. In one case both SEPs and MEPs were not recordable. The monitoring SEP and MEP parameters (latency and amplitude) had a broad interindividual range of variation. A correlation between individual intraoperative potential changes and postoperative neurological deterioration was observed in 10 (18.8%) cases. A spontaneous shift in MEP latency of more than 15%, or a sudden reduction in MEP amplitude of more than 80% correlated significantly (p < 0.01) with postoperative neurological deterioration. Intraoperative SEP changes had a less significant correlation with postoperative clinical deterioration of the motor system.

Conclusions

Amplitude reduction by more than 80% and latency prolongation of more than 15% can be interpreted as intraoperative warning signs of risk of mechanical damage to the motor system. Both intraoperative SEP and MEP have technical, anatomical and neurophysiological limitations. However, a sensitivity of 98.1% was achieved despite these limitations, by combining the two methods. Intraoperative MEP monitoring is more sensitive for the prediction of postoperative clinical deterioration.