gms | German Medical Science

59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

01. - 04.06.2008, Würzburg

Automated real-time monitoring: Intraoperative evaluation of facial nerve function during vestibular schwannoma surgery

Automatisiertes Echtzeit-Monitoring: Die intraoperative Beurteilung der Fazialisfunktion bei Operationen an Vestibularisschwannomen

Meeting Abstract

  • corresponding author J. Prell - Department of Neurosurgery, Martin-Luther-University Halle-Wittenberg
  • S. Rampp - Department of Neurosurgery, Martin-Luther-University Halle-Wittenberg
  • J. Rachinger - Department of Neurosurgery, Martin-Luther-University Halle-Wittenberg
  • C. Scheller - Department of Neurosurgery, Martin-Luther-University Halle-Wittenberg
  • C. Strauss - Department of Neurosurgery, Martin-Luther-University Halle-Wittenberg

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 100

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2008/08dgnc368.shtml

Veröffentlicht: 30. Mai 2008

© 2008 Prell 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: One of the main problems of neurophysiologic monitoring is the ubiquitous time delay needed for analysis of the aquired data. Thus, real-time neuromonitoring is a strongly desired goal. The electrophysiological parameter “traintime” is known to be closely correlated with the extent of postoperative facial nerve paresis. It is a quantitative expression of overall A-train activity. The system presented was designed to monitor traintime in real-time.

Methods: A dedicated hard- and software-platform for automated analysis of the intraoperative facial nerve EMG was specifically designed. It is capable of monitoring 16 EMG-channels simultaneously. The automatic detection of A-trains is performed by a software-algorithm which incorporates several new techniques for real-time analysis of non-stationary biosignals. It is based on morphology, frequency and rhythmic characteristics of electrophysiological EMG-patterns.

Results: Intraoperative A-trains can be detected and measured automatically by the described method for real-time analysis. With the occurrence of A-trains, an acoustic warning-signal is emitted. Each of the three main branches of the facial nerve is monitored with three overlapping channels of virtual bipolar EMG. The predominant channel of each branch is automatically detected and traintime from the three resulting, predominant channels is calculated automatically for the estimation of overall A-train „power“. Traintime is monitored continuously and in real-time via a “traffic lights” display and also shown as an absolute numerical value during the operation. The system was tested in a consecutive series of 16 patients. It correctly foresaw disfiguring facial nerve palsy with high reliability (sensitivity 100%, specificity 67%, negative predictive value 100%, positive predictive value 70%).

Conclusions: Automated real-time-analysis of the intraoperative facial nerve EMG can critically contribute to the estimation of functional outcome in the course of the operative procedure. This option for reliable prognostic statements at any time during the operation can aid in achieving better functional outcomes in acoustic neuroma surgery.