gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Outcome prediction of a single parameter analysis in present somatosensory and acoustic evoked potentials after severe traumatic brain injury

Vorhersage der klinischen Langzeitergebnisse durch Einzelparameteranalyse der frühen somatosensibel und akkustisch evozierten Potentiale nach schwerem Schädel-Hirn-Trauma

Meeting Abstract

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  • corresponding author M.H. Morgalla - Neurochirurgische Klinik, Universität Tübingen
  • J. Bauer - Neurochirurgische Klinik, Universität Tübingen
  • M. Tatagiba - Neurochirurgische Klinik, Universität Tübingen

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 03.37

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

Published: May 8, 2006

© 2006 Morgalla 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.



Objective: The prognosis after severe traumatic brain injury is difficult to determine. The purpose of this study was to examine the prognostic value of a present single parameter in early somatosensory (SSEP) and acoustic (EAEP) evoked potentials in order to predict long-term clinical results.

Methods: This is a retrospective analysis of 100 patients (age 14-85 years, mean age 43,8 years) who suffered from severe traumatic brain injury grade III or IV. On these patients SSEP and EAEP were recorded and the following single parameters examined: Latency and amplitude of N20, latency of N13, central conduction time, amplitude ratio of N20/N13, amplitude difference of N20, amplitudes of peak I-V, absolute latencies of peak I-V, interpeak latencies I-III and III-V and amplitude ratio V/I. The patients were divided into different outcome groups according to the Glasgow outcome scale (GOS) and re-evaluated after 1,3 – 3,9 years (mean 2,65 years) post trauma. Each parameter of the evoked potentials was correlated to the later outcome and the predictive value calculated.

Results: There was no statistical difference between the different mean values of the central conduction time of the N20 (p=0,14). The amplitude ratio of N20 left / N20 right was 1,12 (GOS 1) and 0,98 (GOS 5) with no statistical difference between the different groups (p<0,05). The mean latency of peak V was 6,15 ms (GOS 1) and 5,82 ms (GOS 5). A statistical difference was not evident (p=0,214). The interpeak latency I-V was 4,31 ms (GOS 1) and 4,17 ms (GOS 5) with no statistical difference (p=0,39). The amplitude ratio of peak V/I was 1,57 (GOS 1) and 1,78 (GOS 5). Again, no statistical differences between the single outcome groups could be found (p<0,21).

Conclusions: All examined parameters could not be used alone to predict a long-term clinical result. To achieve this purpose specific combined parameter systems like the Riffel score are necessary.