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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

Doubtful benefit of intra-operative somatosensory evoked potentials (SEP) monitoring including pre-operative positioning tests in patients with degenerative cervical disease

Zweifelhafter Nutzen des intraoperativen SEP-Monitorings inklusive präoperativer Lagerungstests bei Patienten mit degenerativen HWS-Veränderungen

Meeting Abstract

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  • corresponding author Jochen Helm - Universitätsklinikum Leipzig, Klinik für Neurochirurgie, Leipzig
  • C. Rudolph - Universitätsklinikum Leipzig, Klinik für Anästhesie und Intensivmedizin, Leipzig
  • J. Meixensberger - Universitätsklinikum Leipzig, Klinik für Neurochirurgie, Leipzig

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.02.11

The electronic version of this article is the complete one and can be found online at:

Published: April 23, 2004

© 2004 Helm et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




A benefit of intraoperative SSEP monitoring in decompressive surgery for degeneration of cervical spine is generally accepted. In view of the low complication rate and unspecific intraoperative SSEP changes, a final evaluation remains difficult. The aim of the study was an acquisition of preoperative SSEP data in normal, reclined and inclined neck positions and to verify a correlation to the risk of intraoperative changes and postoperative neurological deficits.


From 03/01 to 03/03 we recorded pre-operative and intra-operative SSEP data from 33 patients undergoing operation. We registered the baseline SSEPs as well as influence of pre-operative positioning tests, intra-operative alterations, surgeons reactions and post-operative deficits.


In 24% of the patients there was a pre-operative deterioration of median nerve SSEP (MSEP) signals in positioning tests, in 9% MSEPs improved, in 67% there were stable potentials (TSEP 42% worse, 15% better, 42% unaltered). Intra-operative MSEP deterioration was detected in 76% of the patients, MSEP deterioration in 76% as well. Only in four patients (12%) did we register stable intraoperative SSEP signals. In 8 situations there was an influence of intraoperative SSEP monitoring on the course of the surgery (positioning alteration, increased caution, one operation was aborted). In 4 patients there were postoperative deficits (1 brachiocervical plexus palsy, 2 radicular sensory deficits, 1 new spinal ataxia). Positioning tests of these patients revealed unilateral MSEP twice, and unilateral TSEP deterioration twice; in one patient position testing was without influence on SSEP. In one of the patients there were no intra-operative SSEP changes. In two patients intra-operative alterations did not correlate to neurological deficits, only the patient with the plexus palsy showed unilateral MSEP reduction and delay.


A deterioration of SSEP signals in pre-operative positioning indicated a higher risk of post-operative neurological deficit. However intra-operative alterations were mostly unspecific and did not correlate to post-operative deficits in 3 of our 4 complication patients. The risk of post-operative neurological deficits being reduced by a combination of pre-operative positioning tests and intra-operative SSEP monitoring remains unclear.