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J Neurol Surg A Cent Eur Neurosurg 2021; 82(04): 308-316
DOI: 10.1055/s-0040-1701616
Original Article

Facial Nerve EMG: Low-Tech Monitoring with a Stopwatch

Julian Prell
1   Department of Neurosurgery, University of Halle, Halle, Germany
,
Christian Scheller
1   Department of Neurosurgery, University of Halle, Halle, Germany
,
Sebastian Simmermacher
1   Department of Neurosurgery, University of Halle, Halle, Germany
,
Christian Strauss
1   Department of Neurosurgery, University of Halle, Halle, Germany
,
Stefan Rampp
1   Department of Neurosurgery, University of Halle, Halle, Germany
› Institutsangaben Funding Source All the authors report grants from Deutsche Forschungsgemeinschaft DFG (PR1275/1-2) during the conduct of the study.
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Abstract

Objective The quantity of A-trains, a high-frequency pattern of free-running facial nerve electromyography, is correlated with the risk for postoperative high-grade facial nerve paresis. This correlation has been confirmed by automated analysis with dedicated algorithms and by visual offline analysis but not by audiovisual real-time analysis.

Methods An investigator was presented with 29 complete data sets measured during actual surgeries in real time and without breaks in a random order. Data were presented either strictly via loudspeaker (audio) or simultaneously by loudspeaker and computer screen (audiovisual). Visible and/or audible A-train activity was then quantified by the investigator with the computerized equivalent of a stopwatch. The same data were also analyzed with quantification of A-trains by automated algorithms.

Results Automated (auto) traintime (TT), known to be a small, yet highly representative fraction of overall A-train activity, ranged from 0.01 to 10.86 s (median: 0.58 s). In contrast, audio-TT ranged from 0 to 1,357.44 s (median: 29.69 s), and audiovisual-TT ranged from 0 to 786.57 s (median: 46.19 s). All three modalities were correlated to each other in a highly significant way. Likewise, all three modalities correlated significantly with the extent of postoperative facial paresis. As a rule of thumb, patients with visible/audible A-train activity < 1 minute presented with a more favorable clinical outcome than patients with > 1 minute of A-train activity.

Conclusion Detection and even quantification of A-trains is technically possible not only with intraoperative automated real-time calculation or postoperative visual offline analysis, but also with very basic monitoring equipment and real-time good quality audiovisual analysis. However, the investigator found audiovisual real-time-analysis to be very demanding; thus tools for automated quantification can be very helpful in this respect.

Keywords

facial nerve - neurophysiologic monitoring - vestibular schwannoma - facial palsy - electromyography


Publikationsverlauf

Eingereicht: 19. März 2019

Angenommen: 03. Juli 2019

Artikel online veröffentlicht:
08. Januar 2021

© 2021. Thieme. All rights reserved.

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  • References

  • 1 Hammerschlag PE, Cohen NL. Intraoperative monitoring of facial nerve function in cerebellopontine angle surgery. Otolaryngol Head Neck Surg 1990; 103 (5[Pt 1]): 681-684
    CrossrefPubMedSuche in Google Scholar
  • 2 Harper CM, Daube JR. Facial nerve electromyography and other cranial nerve monitoring. J Clin Neurophysiol 1998; 15 (03) 206-216
    CrossrefPubMedSuche in Google Scholar
  • 3 Jellinek DA, Tan LC, Symon L. The impact of continuous electrophysiological monitoring on preservation of the facial nerve during acoustic tumour surgery. Br J Neurosurg 1991; 5 (01) 19-24
    CrossrefPubMedSuche in Google Scholar
  • 4 Kombos T, Suess O, Kern BC, Funk T, Pietilä T, Brock M. Can continuous intraoperative facial electromyography predict facial nerve function following cerebellopontine angle surgery?. Neurol Med Chir (Tokyo) 2000; 40 (10) 501-505 ; discussion 506–507
    CrossrefPubMedSuche in Google Scholar
  • 5 Prass RL, Kinney SE, Hardy Jr RW, Hahn JF, Lüders H. Acoustic (loudspeaker) facial EMG monitoring: II. Use of evoked EMG activity during acoustic neuroma resection. Otolaryngol Head Neck Surg 1987; 97 (06) 541-551
    CrossrefPubMedSuche in Google Scholar
  • 6 Prass RL, Lüders H. Acoustic (loudspeaker) facial electromyographic monitoring: Part 1. Evoked electromyographic activity during acoustic neuroma resection. Neurosurgery 1986; 19 (03) 392-400
    CrossrefPubMedSuche in Google Scholar
  • 7 Romstöck J, Strauss C, Fahlbusch R. Continuous electromyography monitoring of motor cranial nerves during cerebellopontine angle surgery. J Neurosurg 2000; 93 (04) 586-593
    CrossrefPubMedSuche in Google Scholar
  • 8 Prell J, Rachinger J, Scheller C, Alfieri A, Strauss C, Rampp S. A real-time monitoring system for the facial nerve. Neurosurgery 2010; 66 (06) 1064-1073 ; discussion 1073
    CrossrefPubMedSuche in Google Scholar
  • 9 Prell J, Rampp S, Romstöck J, Fahlbusch R, Strauss C. Train time as a quantitative electromyographic parameter for facial nerve function in patients undergoing surgery for vestibular schwannoma. J Neurosurg 2007; 106 (05) 826-832
    CrossrefPubMedSuche in Google Scholar
  • 10 Prell J, Strauss C, Rachinger J. et al. Facial nerve palsy after vestibular schwannoma surgery: dynamic risk-stratification based on continuous EMG-monitoring. Clin Neurophysiol 2014; 125 (02) 415-421
    CrossrefPubMedSuche in Google Scholar
  • 11 House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985; 93 (02) 146-147
    CrossrefPubMedSuche in Google Scholar
  • 12 Stalberg E, Trontelj JV. Single Fiber Electromyography. Studies in Healthy and Diseased Muscle. 2nd ed. New York, NY: Raven Press; 1994
    Suche in Google Scholar
  • 13 Rampp S, Rachinger J, Scheller C, Alfieri A, Strauss C, Prell J. How many electromyography channels do we need for facial nerve monitoring?. J Clin Neurophysiol 2012; 29 (03) 226-229
    CrossrefPubMedSuche in Google Scholar
  • 14 Prell J, Strauss C, Rachinger J. et al. The intermedius nerve as a confounding variable for monitoring of the free-running electromyogram. Clin Neurophysiol 2015; 126 (09) 1833-1839
    CrossrefPubMedSuche in Google Scholar
  • 15 Alfieri A, Fleischhammer J, Peschke E, Strauss C. The nervus intermedius as a variable landmark and critical structure in cerebellopontine angle surgery: an anatomical study and classification. Acta Neurochir (Wien) 2012; 154 (07) 1263-1268
    CrossrefPubMedSuche in Google Scholar
  • 16 Alfieri A, Fleischhammer J, Prell J. The functions of the nervus intermedius. AJNR Am J Neuroradiol 2011; 32 (07) E144 ; author reply E145
    CrossrefPubMedSuche in Google Scholar
  • 17 Alfieri A, Rampp S, Strauss C. et al. The relationship between nervus intermedius anatomy, ultrastructure, electrophysiology, and clinical function. Usefulness in cerebellopontine microsurgery. Acta Neurochir (Wien) 2014; 156 (02) 403-408
    CrossrefPubMedSuche in Google Scholar
  • 18 Dong CC, Macdonald DB, Akagami R. et al. Intraoperative facial motor evoked potential monitoring with transcranial electrical stimulation during skull base surgery. Clin Neurophysiol 2005; 116 (03) 588-596
    CrossrefPubMedSuche in Google Scholar
  • 19 Fukuda M, Oishi M, Takao T, Saito A, Fujii Y. Facial nerve motor-evoked potential monitoring during skull base surgery predicts facial nerve outcome. J Neurol Neurosurg Psychiatry 2008; 79 (09) 1066-1070
    CrossrefPubMedSuche in Google Scholar
  • 20 Liu BY, Tian YJ, Liu W. et al. Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma. Chin Med J (Engl) 2007; 120 (04) 323-325
    CrossrefPubMedSuche in Google Scholar
  • 21 Matthies C, Raslan F, Schweitzer T, Hagen R, Roosen K, Reiners K. Facial motor evoked potentials in cerebellopontine angle surgery: technique, pitfalls and predictive value. Clin Neurol Neurosurg 2011; 113 (10) 872-879
    CrossrefPubMedSuche in Google Scholar
  • 22 Schmitt WR, Daube JR, Carlson ML. et al. Use of supramaximal stimulation to predict facial nerve outcomes following vestibular schwannoma microsurgery: results from a decade of experience. J Neurosurg 2013; 118 (01) 206-212
    Suche in Google Scholar