Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Management of Patients With Vestibular Schwannoma

Vestibular Schwannoma Guidelines Task Force. (2017).

Schaumburg (IL): Congress of Neurological Surgeons, Retrieved January 17, 2018 from https://www.cns.org/guidelines/browse-guidelines-detail/1-introduction-methods.

This group of guidelines developed by the guidelines committee of the Joint Tumor Section of the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) in 2017  includes nine chapters of recommendations organized by topics for the management of vestibular schwannoma (VS). Only chapters and topics within the scope of audiology are included in this summary. The stated objectives of these guidelines are "to establish the best evidence-based management of VSs, including initial otologic evaluation, imaging diagnosis, use of surgical techniques, assessment of tumor pathology, and the administration of radiation therapy" (Chapter 1, p. 4).

Congress of Neurological Surgeons

Joint Guidelines Committee of the American Association of Neurological Surgeons

<p>This document contains a number of guidelines, only some of which are related to audiology practice. Of particular relevance to the article's recommendations are the following:</p> <ul> <li>Carlson, M. L., Vivas, E. X., et al. (2017). <i>Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Hearing Preservation Outcomes in Patients With Sporadic Vestibular Schwannomas</i>. Retrieved January 17, 2018 from <a href="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-hearing-preservation.pdf" title="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-hearing-preservation.pdf" class="ApplyClass">https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-hearing-preservation.pdf</a></li> <li>Olson, J. J., Kalkanis, S. N., et al. (2017). <i>Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Treatment of Adults With Vestibular Schwannomas: Introduction and Methods</i>. Retrieved January 17, 2018 from <a href="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-introduction-methods.pdf" title="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-introduction-methods.pdf">https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-introduction-methods.pdf</a></li> <li>Olson, J. J., Kalkanis, S. N., et al. (2018). Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Treatment of Adults With Vestibular Schwannomas: Executive Summary. <i>Neurosurgery, 82</i>(2), 129-134. doi:10.1093/neuros/nyx586</li> <li>Sweeney, A. D., Carlson, M. L., et al. (2017). <i>Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Otologic and Audiologic Screening for Patients With Vestibular Schwannomas</i>. Retrieved January 17, 2018 from <a href="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-audiologic-screening.pdf" title="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-audiologic-screening.pdf">https://www.cns.org/sites/default/files/guideline-chapter-pdf/vestibular-schwannoma-audiologic-screening.pdf</a></li> <li>Vivas, E. X., Carlson, M. L., et al. (2017). <i>Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on Intraoperative Cranial Nerve Monitoring in Vestibular Schwannoma Surgery</i>. Retrieved January 17, 2018 from <a href="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vs_cranial_nerve_monitoring.pdf" title="https://www.cns.org/sites/default/files/guideline-chapter-pdf/vs_cranial_nerve_monitoring.pdf">https://www.cns.org/sites/default/files/guideline-chapter-pdf/vs_cranial_nerve_monitoring.pdf</a></li> </ul> <p>The full listing of documents can be found on the <a href="https://www.cns.org/guidelines/browse-guidelines" title="https://www.cns.org/guidelines/browse-guidelines" class="ApplyClass">Congress of Neurological Surgeons'</a> webpage.</p>

<div>Patients should be referred for additional MRI screening to determine the presence of vestibular schwannoma (VS) if they demonstrate one of the following characteristics during their audiologic assessment:</div> <div> <ul> <li>"&gt; 10 dB of interaural difference at 2 or more contiguous frequencies or &ge; 15 dB at one frequency";&nbsp;</li> <li>"&ge; 15 dB of interaural difference at 3000 Hz alone";&nbsp;</li> <li>Asymmetric tinnitus; or</li> <li>Sudden sensorineural hearing loss (Level 3 Evidence; Chapter 2, p. 3).</li> </ul> </div>

<div>Intraoperative monitoring should be utilized during vestibular schwannoma surgery to monitor the facial nerve. Intraoperative electromyogram electrical response of facial nerve is not a reliable predictor of long-term facial nerve function (Level 3 Evidence; Chapter 4).</div>

"Intraoperative eighth cranial nerve monitoring should be used during vestibular schwannoma surgery when hearing preservation is attempted" (Level 3 Evidence; Chapter 4, p. 4). <div>&nbsp;</div> <div>There is insufficient evidence whether direct monitoring of the eighth cranial nerve is superior to the use of far-field auditory brain stem response (Level 3 Evidence; Chapter 4).</div>

Patients receiving conservative observation of their vestibular schwannomas should be counseled on the likelihood of hearing preservation of serviceable hearing across time, at two years, five years, and ten years following diagnosis. Prognostic features to consider for estimating likelihood of hearing preservation include: <div> <ul> <li>Baseline hearing class or grade;</li> <li>Good preoperative word recognition and/or pure tone thresholds with variable cut-points; and</li> <li>Non-growth of the tumor (Level 3 Evidence; Chapter 3).</li> </ul> </div>