Developing Intraoperative Cochlear Nerve Monitoring during Vestibular Schwannoma Surgery

Abstract BACKGROUND Neurofibromatosis type 2 (NF2) often results in profound hearing loss and cochlear implantation is an emerging hearing rehabilitation option. However, cochlear implant (CI) outcomes in this population vary, and intraoperative monitoring to predict cochlear nerve viability and subsequent outcomes is not well-established. OBJECTIVE To review the use of intraoperative electrically evoked cochlear nerve monitoring in patients with NF2 simultaneous translabyrinthine (TL) vestibular schwannoma (VS) resection and cochlear implantation. METHODS A retrospective review was performed of 3 patients with NF2 that underwent simultaneous TL VS resection and cochlear implantation with electrical auditory brainstem response (eABR) measured throughout tumor resection. Patient demographics, preoperative assessments, surgical procedures, and outcomes were reviewed. RESULTS Patients 1 and 3 had a reliable eABR throughout tumor removal. Patient 2 had eABR pretumor removal, but post-tumor removal eABR presence could not be reliably determined because of electrical artifact interference. All patients achieved auditory percepts upon CI activation. Patients 1 and 2 experienced a decline in CI performance after 1 yr and after 3 mo, respectively. Patient 3 continues to perform well at 9 mo. Patients 2 and 3 are daily users of their CI. CONCLUSION Cochlear implantation is attainable in cases of NF2-associated VS resection. Intraoperative eABR may facilitate cochlear nerve preservation during tumor removal, though more data and long-term outcomes are needed to refine eABR methodology and predictive value for this population.

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Vestibular schwannoma surgery: Intraoperative cochlear nerve action potential monitoring

Otolaryngology ◽

10.1016/s0194-5998(97)80454-8 ◽

1997 ◽

Vol 117 (2) ◽

pp. P204-P204

Author(s):

J ROBERSONJR ◽

J MCAULEY

Keyword(s):

Action Potential ◽

Vestibular Schwannoma ◽

Cochlear Nerve ◽

Nerve Action ◽

Potential Monitoring

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Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a “Test Intracochlear Electrode”

Journal of Neurological Surgery Reports ◽

10.1055/s-0038-1673649 ◽

2019 ◽

Vol 80 (01) ◽

pp. e1-e9 ◽

Cited By ~ 2

Author(s):

Anand Kasbekar ◽

Yu Chuen Tam ◽

Robert Carlyon ◽

John Deeks ◽

Neil Donnelly ◽

...

Keyword(s):

Cochlear Implant ◽

Vestibular Schwannoma ◽

Intraoperative Monitoring ◽

Neurofibromatosis Type ◽

Auditory Brainstem ◽

Cochlear Nerve ◽

Auditory Brainstem Responses ◽

Tertiary Referral Center ◽

Objective Evidence ◽

Brainstem Response

Objectives A decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. Design We describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. Setting This study was set at a tertiary referral center for skull base pathology. Main outcome measure Preserved auditory brainstem responses leading to cochlear implantation. Results Electrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. Conclusion Electrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf.

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Stability of hearing preservation and regeneration capacity of the cochlear nerve following vestibular schwannoma surgery via a retrosigmoid approach

Journal of Neurosurgery ◽

10.3171/2015.10.jns15926 ◽

2016 ◽

Vol 125 (5) ◽

pp. 1277-1282 ◽

Cited By ~ 10

Author(s):

Christian Scheller ◽

Andreas Wienke ◽

Marcos Tatagiba ◽

Alireza Gharabaghi ◽

Kristofer F. Ramina ◽

...

Keyword(s):

Vestibular Schwannoma ◽

Strong Association ◽

Pure Tone Audiometry ◽

Hearing Preservation ◽

Cochlear Nerve ◽

Speech Discrimination ◽

Regeneration Capacity ◽

Postoperative Course ◽

Link Type ◽

Hearing Abilities

OBJECTIVE The purpose of this research was to examine the stability of long-term hearing preservation and the regeneration capacity of the cochlear nerve following vestibular schwannoma (VS) surgery in a prospective study. METHODS A total of 112 patients were recruited for a randomized multicenter trial between January 2010 and April 2012 to investigate the efficacy of prophylactic nimodipine treatment versus no prophylactic nimodipine treatment in VS surgery. For the present investigation, both groups were pooled to compare hearing abilities in the early postoperative course and 1 year after the surgery. Hearing was examined using pure-tone audiometry with speech discrimination, which was performed preoperatively, in the early postoperative course, and 12 months after surgery and was subsequently classified by an independent otorhinolaryngologist using the Gardner-Robertson classification system. RESULTS Hearing abilities at 2 time points were compared by evaluation in the early postoperative course and 1 year after surgery in 102 patients. The chi-square test showed a very strong association between the 2 measurements in all 102 patients (p < 0.001) and in the subgroup of 66 patients with a preserved cochlear nerve (p < 0.001). CONCLUSIONS There is no significant change in cochlear nerve function between the early postoperative course and 1 year after VS surgery. The result of hearing performance, as evaluated by early postoperative audiometry after VS surgery, seems to be a reliable prognosticator for future hearing ability. Clinical trial registration nos.: 2009-012088-32 (clinicaltrialsregister.eu) and DRKS 00000328 (“AkNiPro,” drks-neu.uniklinik-freiburg.de/drks_web/)

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Our Experience With Facial Nerve Monitoring in Vestibular Schwannoma Surgery Under Partial Neuromuscular Blockade

Acta Otorrinolaringologica (English Edition) ◽

10.1016/j.otoeng.2014.08.003 ◽

2015 ◽

Vol 66 (4) ◽

pp. 192-198

Author(s):

Jorge Vega-Céliz ◽

Emili Amilibia-Cabeza ◽

José Prades-Martí ◽

Nuria Miró-Castillo ◽

Marta Pérez-Grau ◽

...

Keyword(s):

Facial Nerve ◽

Neuromuscular Blockade ◽

Vestibular Schwannoma ◽

Nerve Monitoring ◽

Facial Nerve Monitoring ◽

Partial Neuromuscular Blockade

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Tumor origin and hearing preservation in vestibular schwannoma surgery

Journal of Neurosurgery ◽

10.3171/2011.7.jns102092 ◽

2011 ◽

Vol 115 (5) ◽

pp. 900-905 ◽

Cited By ~ 9

Author(s):

Jens Rachinger ◽

Stefan Rampp ◽

Julian Prell ◽

Christian Scheller ◽

Alex Alfieri ◽

...

Keyword(s):

Vestibular Schwannoma ◽

Tumor Size ◽

Hearing Preservation ◽

Vestibular Nerve ◽

Cochlear Nerve ◽

Nerve Function ◽

Nerve Preservation ◽

Tumor Origin ◽

Inferior Vestibular Nerve ◽

Vs Removal

Object Preservation of cochlear nerve function in vestibular schwannoma (VS) removal is usually dependent on tumor size and preoperative hearing status. Tumor origin as an independent factor has not been systematically investigated. Methods A series of 90 patients with VSs, who underwent surgery via a suboccipitolateral route, was evaluated with respect to cochlear nerve function, tumor size, radiological findings, and intraoperatively confirmed tumor origin. All patients were reevaluated 12 months after surgery. Results Despite comparable preoperative cochlear nerve status and larger tumor sizes, hearing preservation was achieved in 42% of patients with tumor originating from the superior vestibular nerve, compared with 16% of those with tumor originating from the inferior vestibular nerve. Conclusions Tumor origin is an important prognostic factor for cochlear nerve preservation in VS surgery.

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