Background: The use of intraoperative neurophysiological monitoring, including direct
nerve stimulation (especially the facial nerve), acoustic evoked potentials (AEP) and
somatosensory evoked potentials (SSEP), is a helpful tool in the microsurgery of
vestibular schwannoma to prevent nerve injury. Patient characteristics and intraoperative
and postoperative variables might also influence the postoperative facial nerve function.
The study was performed to investigate these variables and the intraoperative
neurophysiological monitoring values.
Methods: Seventy-nine patients with vestibular schwannoma were included
consecutively into this study. Intraoperative neurophysiological monitoring, including
SSEP, AEP, and direct nerve stimulation for facial and trigeminal nerve electromyography,
was performed utilizing digital data storage in all cases. The intensity (in volts) of the direct
stimulation and the latency (in ms) for the orbicularis oculi and the orbicularis oris muscle
and the amplitude (in mV) was measured. Univariate and multivariate statistical analyses
concerning the different parameters was performed directly after the operation and in the
subsequent follow-ups 3 and 6 months after the operation.
Results: The mean intensity was 0.79 V (SD.29). The latency and amplitude for the
oris muscle was 5.2ms (SD 2.07) and 0.68mV (SD.57), respectively. The mean latency
for the occuli muscle was 5.58ms (SD 2.2) and the amplitude was 0.58mV (SD 1.04).
The univariate and multivariate statistical analyses showed significance concerning the
postoperative facial nerve function and the amplitude of the direct stimulation of the
facial nerve in the orbicularis oris muscle (p = 0.03), so repeated direct nerve stimulation
might show FN function deterioration. The mean diameter of the tumors was 24mm
(range 10–57mm). Cross total resection and near total was achieved in 76 patients
(96%) and subtotal in three patients (4%). The preoperative House–Brakeman score
(HBS) 1 was constant in 65 (82%) cases. The mortality in our series was 0%; the overall
morbidity was 10%. The HBS was not influenced concerning the extent of resection.
The mean follow-up was 28 months (range 6 to 60 months). The limitations of the
study might be a low number of patients and the retrospective character of the study.
Conclusion: Intraoperative neurophysiological monitoring is crucial in vestibular
schwannoma surgery. Repeated direct nerve stimulation and a detected decreased
amplitude might show facial nerve function deterioration.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:86624 |
| Date | 27 July 2023 |
| Creators | Arlt, Felix, Kasper, Johannes, Winkler, Dirk, Jähne, Katja, Fehrenbach, Michael Karl, Meixensberger, Jürgen, Sander, Caroline |
| Publisher | Frontiers Research Foundation |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1664-2295, 850326 |
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