Cochlear Implantation in Sporadic Vestibular Schwannoma: A Systematic Literature Review

Cochlear implant procedure. Italian Clinical Practice Guidelines of the Italian Society of Otorhinolaryngology (SIOeChCF) and Italian Society of Audiology and Phoniatrics (SIAF). Part 1: cochlear implants in adults

Objective

Cochlear implant (CI) is a well-established treatment for adults with sensorineural hearing loss and without benefit from hearing aids. The Italian guidelines date back 15 years; given the expansion of indications for CI, including single side deafness and asymmetrical hearing loss, it became necessary to establish updated guidelines.

Methods

Thirteen experts and 2 patient representatives selected the key questions and drew up recommendations. The document was developed following GRADE methodology. The methodological team of the Mario Negri Pharmacological Research Institute performed systematic reviews for each question and supported the overall process.

Results

Five key questions were identified and recommendations formulated, with subgroups and considerations on implementation.

Conclusions

Though the systematic research of scientific literature found a scarcity of randomised trials and an overall poor conduct and reporting quality of primary studies and systematic reviews, strong or conditional recommendations in favour of CI have been formulated for different subgroups of patients. Further studies should enrol a larger number of participants and use consistent instruments to evaluate hearing outcomes, in order to increase the comparability of results and data pooling with meta-analysis.

Brazilian Society of Otology task force - cochlear implant ‒ recommendations based on strength of evidence

OBJECTIVE

To make evidence-based recommendations for the indications and complications of Cochlear Implant (CI) surgery in adults and children.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on cochlear implantation were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Evaluation of candidate patients and indications for CI surgery; (2) CI surgery - techniques and complications.

CONCLUSIONS

CI is a safe device for auditory rehabilitation of patients with severe-to-profound hearing loss. In recent years, indications for unilateral hearing loss and vestibular schwannoma have been expanded, with encouraging results. However, for a successful surgery, commitment of family members and patients in the hearing rehabilitation process is essential.

Comparing Cochlear Implant Outcomes in 100 Patients With Sporadic Vestibular Schwannoma Managed With Observation, Radiosurgery, or Microsurgery: A Multi-Institutional Review

OBJECTIVE

To compare cochlear implant (CI) speech perception outcomes in patients with sporadic vestibular schwannoma (VS) managed with observation, radiosurgery, or microsurgery.

STUDY DESIGN

Retrospective review.

SETTING

Eleven tertiary academic medical centers.

PATIENTS

One hundred patients with sporadic VS who received an ipsilateral CI.

INTERVENTIONS

Ipsilateral cochlear implantation.

MAIN OUTCOME MEASURES

Pure-tone thresholds, monosyllabic speech perception testing scores, and rates of open-set speech acquisition.

RESULTS

Of the 100 patients studied, 54 underwent microsurgery, 26 underwent radiosurgery, 19 continued observation, and 1 underwent multimodal therapy. Among all patients, the median post-implantation pure-tone average was 31 dB (interquartile range [IQR] 25-39 dB) and the median monosyllabic speech perception score was 30% (IQR 0-60%) at a median of 12 months (IQR 5-25 months) post-implantation. Patients who were managed with microsurgery (median speech perception score 11%, IQR 0-52%) exhibited poorer implant outcomes overall compared with those managed with observation (median speech perception score 52%, IQR 40-72%) or radiosurgery (median speech perception score 30%, IQR 16-60%). Open-set speech perception was achieved in 61% of patients managed with microsurgery, 100% with observation, and 80% with radiosurgery. In a multivariable setting, those managed with observation (p = 0.02) or who underwent radiosurgery (p = 0.04) were significantly more likely to achieve open-set speech perception compared with patients who underwent microsurgery.

CONCLUSIONS

Cochlear implants offer benefit in selected patients with sporadic VS. Although achieved in over half of people after microsurgery, open-set speech perception is more reliably attained in patients who are treated with observation or radiosurgery compared with microsurgical resection. These data may inform patient counseling and VS tumor management in people who may benefit from implantation.

Brazilian Society of Otology task force - Vestibular Schwannoma ‒ evaluation and treatment

OBJECTIVE

To review the literature on the diagnosis and treatment of vestibular schwannoma.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on vestibular schwannoma were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Diagnosis - audiologic, electrophysiologic tests, and imaging; (2) Treatment - wait and scan protocols, surgery, radiosurgery/radiotherapy, and systemic therapy.

CONCLUSIONS

Decision making in VS treatment has become more challenging. MRI can diagnose increasingly smaller tumors, which has disastrous consequences for the patients and their families. It is important to develop an individualized approach for each case, which highly depends on the experience of each surgical team.

A novel intraoperative continuous monitoring method combining dorsal cochlear nucleus action potentials monitoring with auditory nerve test system

Highly accurate real-time cochlear nerve monitoring to preserve cochlear nerve function is essential for simultaneous cochlear implantation and ipsilateral vestibular schwannoma resection. In the present study, we developed a novel real-time monitoring system that combines dorsal cochlear nucleus action potential monitoring with intracochlear stimulating electrodes (Auditory Nerve Test System, ANTS). We used this system for a case with vestibular schwannoma resection via the translabyrinthine approach. The monitoring system developed in this study detected highly reliable evoked potentials from the cochlear nerve every two seconds continuously during tumor resection. Near-total tumor resection was achieved, and cochlear implantation was performed successfully after confirming the preservation of cochlear nerve function in a case. The patient's hearing was well compensated by cochlear implantation after surgery. Our novel method continuously achieved real-time monitoring of the cochlear nerve every two seconds during vestibular schwannoma resection. The usefulness of this monitoring system for simultaneous tumor resection and cochlear implantation was demonstrated in the present case. The system developed in this study is compatible with continuous facial nerve monitoring. This highly accurate and novel monitoring method will broaden the number of candidates for this type of surgery in the future.

Hearing Rehabilitation in Vestibular Schwannoma

The most common complaint among patients with vestibular schwannoma (VS) is hearing loss. This significantly affects the quality of life before, during, and after treatment for patients with VS. Untreated hearing loss in VS patients may even lead to depression and feelings of social isolation. A variety of devices are available for hearing rehabilitation for patients with vestibular schwannoma. These include contralateral routing of hearing signals (CROSs), bone-anchored hearing devices, auditory brainstem implants (ABI), and cochlear implants. In the United States, ABI is approved for patients 12 years of age and older with neurofibromatosis type 2. In the past few years, cochlear implantation has been offered simultaneously or sequentially with tumor resection or irradiation, or even to patients whose VS have been monitored with serial imaging. However, determining the functional integrity of the auditory nerve in patients with vestibular schwannoma is a challenge. This review article consists of (1) the pathophysiology of vestibular schwannoma (VS), (2) hearing loss in VS, (3) treatment of VS and associated hearing loss, (4) options for auditory rehabilitation in patients with VS with their individual benefits and limitations, and (5) challenges in hearing rehabilitation in this cohort of patients to determine auditory nerve functionality. (6) Future directions.

Cochlear Implantation in Sporadic Vestibular Schwannoma and Neurofibromatosis Type II

Cochlear implantation offers significantly better hearing outcomes than auditory brainstem implantation in patients with vestibular schwannoma. Neither the primary treatment modality nor the cause of the tumor (neurofibromatosis type 2 related or sporadic) seems to have a significant effect on hearing outcome with cochlear implantation. Some uncertainty remains regarding long-term hearing outcomes; however, cochlear implantation in vestibular schwannoma serves to offer patients, with a functioning cochlear nerve, the probability of open set speech discrimination with a consequent positive impact on quality of life.

Cochlear Implantation Outcomes in Patients With Retrocochlear Pathology: A Systematic Review and Pooled Analysis

OBJECTIVE

To review the current literature regarding cochlear implantation in patients with retrocochlear pathologies and extract speech perception scores between 6 months and 1 year after surgery.

DATABASES REVIEWED

PubMed/MEDLINE, Embase and Cochrane CENTRAL via Ovid, CINAHL Complete via Ebsco, and Web of Science.

METHODS

The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Search strategies included keywords and subject headings to maximize retrieval and reflect cochlear implants and retrocochlear pathologies. Patients with previously resected vestibular schwannoma (VS) were excluded.

RESULTS

There were 2,524 abstracts screened against inclusion criteria, and 53 studies were included, with individual data available for 171 adult patients. Pathologies included were either observed or irradiated VS (previously operated tumors were excluded) (n = 99, 57.9%), superficial siderosis (n = 39, 22.8%), neurosarcoidosis (n = 11, 6.4%), and previous central nervous system or skull base radiation (n = 22, 12.9%). Mean (standard deviation) postoperative consonant-nucleus-consonant (CNC) word scores were 45.4% (24.2) for observed VS, 44.4% (20.8) for irradiated VS, 43.6% (21.0) for superficial siderosis, 89.5% (3.0) for neurosarcoidosis, and 30.0% (30.2) in patients with previous central nervous system or skull base irradiation. Irradiated compared with observed VS had similar postoperative CNC word scores (effect size, 0.06; p = 0.71). Age, sex, maximal tumor dimension, and neurofibromatosis type 2 status did not significantly impact cochlear implant performance in patients with VS. Eighty-two percent of patients with reported device usage were daily users, and overall, 82% of cases benefitted from cochlear implantation.

CONCLUSION

Cochlear implantation in patients with concomitant retrocochlear pathology generally results in improved speech discrimination scores sustained over time.

Is the intra-operative morphology of the cochlear nerve a good predictor of the results of simultaneous ipsilateral cochlear implantation in vestibular schwannoma surgery?

OBJECTIVE

There are currently no guidelines for simultaneous vestibular schwannoma surgery and cochlear implantation. This paper therefore provides our experience and our results regarding predictive parameters of good hearing.

METHODS

Morphological appearance of the cochlear nerve after tumour resection was used as the main criterion for implantation in the case series. Patients were then divided into responders and non-responders to cochlear implantation, and potential outcome predicting factors were evaluated in the two groups.

RESULTS

Nine of the 16 patients showed a response to cochlear implantation. Pre-surgery serviceable hearing was significantly more common in the responder group, while no difference was found in the two groups for other variables.

CONCLUSION

This study highlights how the morphological appearance of the cochlear nerve can be useful to predict the hearing outcome and indicates that satisfactory hearing results are closely related to pre-surgery serviceable hearing.

Progression of Hearing Loss in Observed Non-Growing Vestibular Schwannoma

OBJECTIVE

To assess hearing outcomes in observed vestibular schwannoma (VS) with focus on non-growing tumors.

STUDY DESIGN

Retrospective review.

SETTING

Two tertiary neurotology centers.

PATIENTS AND INTERVENTIONS

Patients with sporadic VS undergoing at least 3 years' observation.

MAIN OUTCOME MEASURES

Changes in pure tone averages (PTA) and word recognition scores (WRS) normalized to the contralateral ear.

RESULTS

During the study period, 39 of 105 included patients (37.1%) had tumor growth. Patients with tumor growth had a mean normalized increase in PTA of 8.0 dB HL (p = 0.008) corresponding to a normalized average worsening of their PTA of 1.8 dB per year. Patients with non-growing tumors less than 5 mm in maximal dimension did not have significant ongoing normalized hearing loss (p > 0.05). Patients with non-growing tumors more than or equal to 5 mm had a mean normalized increase in PTA of 7.4 dB HL (p = 0.001) corresponding to an average of 2.0 dB HL per year, which was similar to the loss observed in growing tumors regardless of size (p > 0.05). Normalized decline in PTA of at least 5 dB HL was seen in 72% of patients with growing tumors, 53% of patients with nongrowing tumors more than or equal to 5 mm, and 38% of patients with non-growing tumors less than 5 mm.

CONCLUSIONS

A long-term analysis of hearing outcomes in observed vestibular schwannoma is presented. With observation, VS more than or equal to 5 mm is associated with continued hearing loss even without tumor growth, while non-growing tumors less than 5 mm are not associated with continuing hearing loss. These data inform expectations for observed VS for providers and patients.

Cochlear implant in vestibular schwannomas: long-term outcomes and critical analysis of indications

PURPOSE

To describe our institutional experience in cochlear implantation after vestibular schwannoma (VS) resection, and compare the audiological outcomes between sporadic and neurofibromatosis type 2 (NF2) VS sub-cohorts of patients, and in relation to preoperative contralateral hearing.

METHODS

Seventeen patients (8 sporadic and 9 NF2-associated VSs) who had undergone VS resection and cochlear implant (CI) were analyzed retrospectively. Audiological outcomes at 24 months were correlated with preoperative clinical variables. The results according to VS type (sporadic vs. NF2-associated) and contralateral hearing (impaired vs. normal) were compared.

RESULTS

Fourteen CIs were actively used by the patients (77.8%). Twenty-four months after CI activation, the median postoperative PTA (pure tone average) was 45.6 dB nHL and a measurable WRS (Word Recognition Score) was achieved by 44.4% of patients (median WRS = 40%). The median postoperative PTA in the implanted ear resulted better in the group with an impaired contralateral hearing (36.3 dB nHL vs. 78.8 dB nHL, p = 0.019). Good preoperative contralateral hearing status (A-B classes of AAO-HNS) was a negative prognostic factor for CI performance on open-set discrimination (OR = 28.0, 95% CI 2.07-379.25, p = 0.012).

CONCLUSIONS

CI is a viable rehabilitative option for patients with sporadic or NF2-associated VS. A good contralateral hearing adversely affects CI outcome and should be taken into consideration for patients' selection and rehabilitation programs.

Hearing Preservation Microsurgery in Vestibular Schwannomas: Worth Attempting in "Larger" Tumors?

OBJECTIVES/HYPOTHESIS

To review hearing preservation after microsurgical resection of sporadic vestibular schwannomas according to tumor size.

STUDY DESIGN

Retrospective cohort.

METHODS

Baseline, intraoperative, and postoperative patient and tumor characteristics were retrospectively collected for a cohort who underwent hearing preservation microsurgery. Serviceable hearing was defined by a pure tone average ≤50 dB and word recognition score ≥50%.

RESULTS

A total of 243 patients had serviceable hearing preoperatively. Fifty (21%) tumors were confined to the internal auditory canal, and the median tumor size was 16.2 mm (interquartile range [IQR] 11.3-23.2) for tumors with cerebellopontine angle extension. Serviceable hearing was maintained in 64% of patients with tumors confined to the internal auditory canal, 28% with cerebellopontine angle extension <15 mm, and 9% with cerebellopontine angle extension ≥15 mm. On multivariable analysis, the odds ratios of acquiring nonserviceable hearing postoperatively for tumors extending <15 mm and ≥15 mm into the cerebellopontine angle were 5.75 (95% confidence interval [CI] 2.13-15.53; P < .001) and 22.11 (95% CI 7.04-69.42; P < .001), respectively, compared with intracanalicular tumors.

CONCLUSIONS

The strongest predictor of hearing preservation with microsurgery after multivariable adjustment is tumor size. Approximately 10% of patients with tumors ≥15 mm of cerebellopontine angle extension will retain serviceable hearing after microsurgery. Furthermore, hearing preservation techniques offer cochlear nerve preservation and cochlear patency allowing for possible future cochlear implantation. An attempt at hearing preservation, including avoiding surgical approaches that necessarily sacrifice hearing, is worthwhile even in larger tumors if serviceable hearing is present preoperatively.

LEVEL OF EVIDENCE

IV Laryngoscope, 2021.

Cochlear Implantation in Vestibular Schwannoma: A Systematic Literature Review

Objective  Ipsilateral cochlear implantation (CI) in vestibular schwannoma (VS) has been an emerging trend over the last two decades. We conducted the first systematic review of hearing outcomes comparing neurofibromatosis 2 (NF2) and sporadic VS undergoing CI. A comparison of the two populations and predictor of outcome was assessed. This is an update to a previously presented study. Data Sources  Systemic data searches were performed in PubMed NCBI and Scopus by an academic librarian. No restrictions based on the year of publication were used. Study Selection  Studies were selected if patients had a diagnosis of NF2 and a CI placed in the affected side with reports of hearing outcome. Two independent reviewers screened each abstract and full-text article. Data Extraction  Studies were extracted at the patient level, and the assessment of quality and bias was evaluated according to the National Institutes of Health Quality Assessment Tool. Main Outcome Measures  Outcome predictors were determined by using the chi-square test and Student's t -test. Results  Overall, most CI recipients functioned in the high-to-intermediate performer category for both sporadic and NF2-related VS. Median AzBio (Arizona Biomedical Institute Sentence Test) was 72% (interquartile range [IQR]: 50) in NF2 patients and 70% (IQR: 7.25) in sporadic patients. Larger tumor size predicted a poorer final audiometric outcome. Conclusions  Categorization of hearing outcome into superior performance and inferior performance based on sentence recognition revealed a generally good hearing outcome regardless of treatment or patient population. Select patients with sporadic and NF2 VS may benefit from CI.

Simultaneous Cochlear Implantation After Translabyrinthine Vestibular Schwannoma Resection: A Report of 41 Cases

OBJECTIVE

To study the auditory outcome of simultaneous translabyrinthine vestibular schwannoma (VS) resection and cochlear implantation (CI) after successful cochlear nerve preservation.

STUDY DESIGN

A retrospective case series and patient questionnaire.

SETTING

Quaternary referral center for skull base pathologies.

PATIENTS

Patients with small (<2 cm) sporadic or neurofibromatosis 2 related tumors were included in this study.

INTERVENTION

Vestibular schwannoma resection + simultaneous cochlear implantation.

MAIN OUTCOME MEASURE

Audiological performance postimplantation and perceived patients' benefits.

RESULTS

Forty-one patients were included. Thirty-three were sporadic VS and eight were neurofibromatosis 2. Auditory perception postimplantation was achieved in 33 patients (80.5%). At the last follow-up, 20 patients (48.8%) were users and 21 (51.2%) were nonusers. In the users' group, and after 1 year of implant activation, vowel identification was 75.3%, disyllabic word recognition 54%, sentence recognition 60.7%, and common phrase comprehension 61%, whereas in the nonusers' group and after 1 year of implant activation, vowel identification was 22.9%, disyllabic word recognition 14.8%, sentence recognition 15.3%, and common phrase comprehension 14%. Sixteen users were classified into 10 high performers, three intermediate performers, and three poor performers. In the user' group, the mean postimplantation pure tone average was 63.4 dB and the mean speech discrimination score was 63.7%.

CONCLUSIONS

Simultaneous CI and VS resection is a viable option with many patients achieving auditory perception and nearly half the patients are CI users at long follow-up.

Iatrogenic Third Window After Retrosigmoid Approach to a Vestibular Schwannoma Managed with Cochlear Implantation

OBJECTIVE

To present a case of an iatrogenic inner ear third window after vestibular schwannoma microsurgery.

PATIENTS

A 42-year-old male presented 9-months after left-sided retrosigmoid approach for an intracanalicular vestibular schwannoma with hearing-preservation attempt performed elsewhere. Immediately postoperatively, he developed the following disabling and persistent symptoms on the ipsilateral side: autophony, pulsatile tinnitus, high-pitched ringing tinnitus, and hearing his footsteps. He denied vertigo. Otoscopy was normal. Tuning fork (512-Hz) lateralized to the left and Rinne was negative on the left. Audiogram demonstrated a severe mixed hearing loss and 10% aided word-recognition score. High-resolution CT demonstrated violation of the common crus and dehiscence of bone along the medial vestibule suggestive of an iatrogenic inner ear third window.

INTERVENTIONS

Labyrinthectomy and concurrent cochlear implantation.

MAIN OUTCOME MEASURES

Resolution of third window symptoms, open-set speech recognition, tinnitus suppression.

RESULTS

Patient reported immediate resolution of third window symptoms after labyrinthectomy and cochlear implantation. He demonstrates open-set word recognition of 64% at 1-year postoperatively and tinnitus suppression with his cochlear implant on.

CONCLUSIONS

Iatrogenic third window symptoms can occur after hearing-preservation vestibular schwannoma microsurgery. Patients with sufficient hearing preservation who are disabled by third window symptoms yet lack sound clarity and useful hearing may be considered for labyrinthectomy and concurrent cochlear implantation. This intervention effectively extinguishes third window symptoms by destroying residual auditory function and simultaneously provides an opportunity to restore useful hearing and suppress tinnitus, thereby enhancing overall quality of life.

Hydroxyapatite cement cranioplasty in the setting of simultaneous translabyrinthine resection of cerebellopontine angle tumors and cochlear implantation

Cochlear implantation (CI) has become an option for the treatment of hearing loss after translabyrinthine resection of vestibular schwannomas. The surgical video presents the case of a 67-year-old male who had translabyrinthine resection of vestibular schwannoma with simultaneous CI and closure with a hydroxyapatite (HA) cement cranioplasty. HA cement cranioplasty can be utilized in place of abdominal fat graft for the closure of translabyrinthine approaches with similar efficacy and complication profile. To the authors’ knowledge, this is the first reported case of a simultaneous CI and translabyrinthine resection of vestibular schwannoma with HA cement cranioplasty.

The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID211

Cochlear Implantation Outcomes in Observed Vestibular Schwannoma: A Preliminary Report

OBJECTIVE

Over the last decade there has been a trend toward observation for small nongrowing vestibular schwannoma (VS). Even without tumor growth, patients commonly experience ipsilateral hearing decline, and hearing rehabilitation remains challenging. This study analyzes hearing and speech performance outcomes after cochlear implantation (CI) in observed VS.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary referral center.

METHODS

Chart review was used to include patients with observed VS who had undergone ipsilateral CI, pre- and postimplantation audiometry, and speech performance. Tumor size pre- and postimplantation was measured with volumetric analysis.

RESULTS

Seven patients with ipsilateral VS and CI were identified. Preimplantation tumor volume was 0.11 to 1.02 cm³. Five subjects were implanted with a straight electrode and two with a perimodiolar electrode. The average preimplant pure tone average was 91.3 dB (range, 80-117 dB) and 61.2 dB (range, 12-118 dB) for the implanted and nonimplanted ears, respectively. In all subjects with at least 1 year of listening experience (n = 6), consonant-nucleus-consonant word scores improved at 6 months and 1 year in the CI-alone and bimodal listening conditions. AzBio scores in quiet also improved at 6 months and 1 year. Of subjects with serial pre- and postoperative magnetic resonance imaging, volumetric analysis demonstrated no tumor growth.

CONCLUSION

Our results demonstrate that CI is a successful option for subjects with small nongrowing VS. All subjects had improved performance postimplantation. VS may continue to be observed with serial magnetic resonance imaging given increasing conditionality among CI manufacturers and ability to assess cerebellopontine angle extension despite implant artifact.

Cochlear implantation after radiosurgery for vestibular schwannoma

OBJECTIVE

The object of this study was to ascertain outcomes of cochlear implantation (CI) following stereotactic radiosurgery (SRS) for vestibular schwannoma (VS).

METHODS

The authors conducted a retrospective chart review of adult patients with VS treated with SRS who underwent CI between 1990 and 2019 at a single tertiary care referral center. Patient demographics, tumor features, treatment parameters, and pre- and postimplantation audiometric and clinical outcomes are presented.

RESULTS

Seventeen patients (18 ears) underwent SRS and ipsilateral CI during the study period. Thirteen patients (76%) had neurofibromatosis type 2 (NF2). Median age at SRS and CI were 44 and 48 years, respectively. Median time from SRS to CI was 60 days, but notably, 4 patients underwent SRS and CI within 1 day and 5 patients underwent CI more than 7 years after SRS. Median marginal dose was 13 Gy. Median treatment volume at the time of SRS was 1400 mm3 (range 84-6080 mm3, n = 15 patients). Median post-CI PTA was 28 dB HL, improved from 101 dB HL preoperatively (p < 0.001). Overall, 11 patients (12 ears) exhibited open-set speech understanding. Sentence testing was performed at a median of 10 months (range 1-143 months) post-CI. The median AzBio sentence score for patients with open-set speech understanding was 76% (range 19%-95%, n = 10 ears). Two ears exhibited Hearing in Noise Test (HINT) sentence scores of 49% and 95%, respectively. Four patients achieved environmental sound awareness without open-set speech recognition. Two had no detectable auditory percepts.

CONCLUSIONS

Most patients who underwent CI following SRS for VS enjoyed access to sound at near-normal levels, with the majority achieving good open-set speech understanding. Implantation can be performed immediately following SRS or in a delayed fashion, depending on hearing status as well as other factors. This strategy may be applied to cases of sporadic or NF2-associated VS.

ABBREVIATIONS

AAO-HNS = American Academy of Otolaryngology-Head and Neck Surgery; ABI = auditory brainstem implant; CI = cochlear implantation; CN = cranial nerve; CNC = consonant-nucleus-consonant; CPA = cerebellopontine angle; EPS = electrical promontory stimulation; ESA = environmental sound awareness; HINT = Hearing in Noise Test; IAC = internal auditory canal; NF2 = neurofibromatosis type 2; OSP = open-set speech perception; PTA = pure tone average; SRS = stereotactic radiosurgery; VS = vestibular schwannoma; WRS = word recognition score.

Cochlear Implantation in Sporadic Vestibular Schwannoma and Other Retrocochlear Pathology: A Case Series

OBJECTIVE

To describe outcomes with cochlear implantation (CI) for rehabilitation of hearing loss in patients with sporadic vestibular schwannomas (VS) and other retrocochlear pathologies.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary-care center.

PATIENTS

Twenty three cases in 19 patients (53% men, mean age 55.8 yr) with non-neurofibromatosis type 2 related retrocochlear pathology.

INTERVENTIONS

Unilateral or bilateral CI.

MAIN OUTCOME MEASURES

Word recognition score, device usage.

RESULTS

Etiology of deafness included sporadic VS (n = 9, 39%), radiation after head and neck or central nervous system (CNS) malignancy (n = 8, 35%), superficial siderosis (n = 3, 13%), neurosarcoidosis (n = 2, 9%), and pontine stroke (n = 1, 4%). Mean follow-up duration was 2.3 years (standard deviation [SD] 3.0; range, 0.2-9.4). Auditory perception was achieved in 20 out of 22 patients (91%) who have been activated. Mean WRS in patients with sporadic VS was 18% (SD 20; range, 0-44). Mean WRS in patients with non-VS retrocochlear pathology was 55% (SD 30; range, 0-94). Data logs showed 7.0 h/d of average use (SD 4.3; range, 0-13).

CONCLUSIONS

Appropriately selected patients with retrocochlear pathology may benefit from CI so long as the patient has a cochlear fluid signal and an intact cochlear nerve. Patients with sporadic VS patients and normal contralateral hearing exhibited guarded outcomes with CI, whereas most patients with non-VS retrocochlear pathologies demonstrated open-set speech understanding scores comparable to or slightly worse than conventional CI candidates. Since variable performance benefit is observed with CI in patients with retrocochlear pathology, counseling is imperative to align patient expectations with realistic outcomes.

Management of transmodiolar and transmacular cochleovestibular schwannomas with and without cochlear implantation

Introduction

Hearing rehabilitation with cochlear implants has attracted increasing interest also for patients with cochleovestibular schwannoma. The authors report their experience with the surgical management of tumors with rare transmodiolar or transmacular extension and outcomes after cochlear implantation (CI).

Methods

This retrospective case series included nine patients with either primary intralabyrinthine tumors or secondary invasion of the inner ear from the internal auditory canal. The primary endpoint with CI, performed in six patients, was word recognition score at 65 dB SPL (sound pressure level). Secondary endpoints were intra- and postoperative electrophysiological parameters, impedance measures, the presence of a wave V in the electrically evoked (via the CI) auditory brainstem responses, the specifics of postoperative CI programming, and adverse events.

Results

Hearing rehabilitation with CI in cases of transmodiolar tumor growth could be achieved only with incomplete tumor removal, whereas tumors with transmacular growth could be completely removed. All six patients with CI had good word recognition scores for numbers in quiet conditions (80–100% at 65 dB SPL, not later than 6 to 12 months post CI activation). Four of these six patients achieved good to very good results for monosyllabic words within 1–36 months (65–85% at 65 dB SPL). The two other patients, however, had low scores for monosyllables at 6 months (25 and 15% at 65 dB SPL, respectively) with worsening of results thereafter.

Conclusions

Cochleovestibular schwannomas with transmodiolar and transmacular extension represent a rare entity with specific management requirements. Hearing rehabilitation with CI is a principal option in these patients.

Video online

The online version of this article (10.1007/s00106-020-00919-9) includes a video (2D and 3D versions) of the described surgical technique. Article and supplementary material are available at www.springermedizin.de. Please enter the title of the article in the search field, the supplementary material can be found under “Ergänzende Inhalte”.

Surgical management for large vestibular schwannomas: a systematic review, meta-analysis, and consensus statement on behalf of the EANS skull base section

BACKGROUND AND OBJECTIVE

The optimal management of large vestibular schwannomas continues to be debated. We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of this problem from a European perspective.

MATERIAL AND METHODS

A systematic review of MEDLINE database, in compliance with the PRISMA guidelines, was performed. A subgroup analysis screening all surgical series published within the last 20 years (January 2000 to March 2020) was performed. Weighted summary rates for tumor resection, oncological control, and facial nerve preservation were determined using meta-analysis models. This data along with contemporary practice patterns were discussed within the task force to generate consensual recommendations regarding preoperative evaluations, optimal surgical strategy, and follow-up management.

RESULTS

Tumor classification grades should be systematically used in the perioperative management of patients, with large vestibular schwannomas (VS) defined as > 30 mm in the largest extrameatal diameter. Grading scales for pre- and postoperative hearing (AAO-HNS or GR) and facial nerve function (HB) are to be used for reporting functional outcome. There is a lack of consensus to support the superiority of any surgical strategy with respect to extent of resection and use of adjuvant radiosurgery. Intraoperative neuromonitoring needs to be routinely used to preserve neural function. Recommendations for postoperative clinico-radiological evaluations have been elucidated based on the surgical strategy employed.

CONCLUSION

The main goal of management of large vestibular schwannomas should focus on maintaining/improving quality of life (QoL), making every attempt at facial/cochlear nerve functional preservation while ensuring optimal oncological control, thereby allowing to meet patient expectations. Despite the fact that this analysis yielded only a few Class B evidences and mostly expert opinions, it will guide practitioners to manage these patients and form the basis for future clinical trials.

[Management of transmodiolar and transmacular cochleovestibular schwannomas with and without cochlear implantation. German version]

INTRODUCTION

Hearing rehabilitation with cochlear implants has attracted increasing interest also for patients with cochleovestibular schwannoma. The authors report their experience with the surgical management of tumors with rare transmodiolar or transmacular extension and outcomes after cochlear implantation (CI).

METHODS

This retrospective case series included nine patients with either primary intralabyrinthine tumors or secondary invasion of the inner ear from the internal auditory canal. The primary endpoint with CI, performed in six patients, was word recognition score at 65 dB SPL (sound pressure level). Secondary endpoints were intra- and postoperative electrophysiological parameters, impedance measures, the presence of a wave V in the electrically evoked (via the CI) auditory brainstem responses, the specifics of postoperative CI programming, and adverse events.

RESULTS

Hearing rehabilitation with CI in cases of transmodiolar tumor growth could be achieved only with incomplete tumor removal, whereas tumors with transmacular growth could be completely removed. All six patients with CI had good word recognition scores for numbers in quiet conditions (80-100% at 65 dB SPL, not later than 6 to 12 months post CI activation). Four of these six patients achieved good to very good results for monosyllabic words within 1-36 months (65-85% at 65 dB SPL). The two other patients, however, had low scores for monosyllables at 6 months (25 and 15% at 65 dB SPL, respectively) with worsening of results thereafter.

CONCLUSIONS

Cochleovestibular schwannomas with transmodiolar and transmacular extension represent a rare entity with specific management requirements. Hearing rehabilitation with CI is a principal option in these patients.

[Hearing classification in patients with vestibular schwannoma using German-language test procedures]

BACKGROUND

Hearing function in patients with vestibular schwannoma is often classified according to the Gardner and Robertson (1988) or the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS, 1995) systems. These classification systems are based on English-language test procedures, there is no German-language equivalent. The aim of the study was to investigate the influence of various target parameters on hearing classification and to derive a recommendation for the use of German-language test methods.

MATERIALS AND METHODS

The rules for speech audiometry based on English-language test procedures were applied to German speech test materials. In 91 patients with vestibular schwannoma, pure tone hearing thresholds, speech recognition thresholds, and speech discrimination at different sound pressure levels were measured. The patients were categorized according to the Gardner and Robertson and AAO-HNS classifications.

RESULTS

In both the Gardner-Robertson and the AAO-HNS classifications, the number of patients in the hearing classes with serviceable hearing function (measured as Pure Tone Average across three (3PTA) or four (4PTA) frequencies) was highest when using the 3PTA_{0,5;1;2 kHz} condition, followed by 4PTA_{0,5;1;2;3 kHz}, 4PTA_{0,5;1;2;4 kHz}, and 4PTA_{0,5;1;2;"3"kHz}. If maximum word recognition score (WRS_max) was used instead of word recognition 40 dB above the sensation level (WRS_40SL), more patients were classified into the hearing classes with serviceable hearing function, irrespective of the mean pure tone hearing threshold.

CONCLUSION

The Gardner-Robertson and AAO-HNS classifications can be used in German-speaking settings. The Freiburg monosyllabic test can be used to determine speech discrimination scores or maximum word recognition.

Evolving Criteria for Adult and Pediatric Cochlear Implantation

The indications for cochlear implantation have gradually expanded as advancements in technology have evolved, resulting in improved audiologic outcomes for both adult and children. There remains a significant underutilization of cochlear implant technology in the United States, and recognition of the potential benefits of cochlear implantation for non-traditional indications is critical for encouraging the evolution of candidacy criteria. Adult cochlear implantation candidacy has progressed from patients with bilateral profound sensorineural hearing loss (SNHL) to include patients with greater degrees of residual hearing, single-sided deafness and asymmetric hearing, and atypical etiologies of hearing loss (eg, vestibular schwannoma, Ménière's disease, and otosclerosis). Indications for pediatric cochlear implantation have similarly evolved from children with bilateral severe to profound SNHL to implanting children at a younger age, including those with residual hearing, asymmetric hearing loss, inner ear malformations, as well as cochlear nerve deficiency. In this editorial, the literature investigating cochlear implantation for nontraditional indications is reviewed with an aim to use the best available evidence to encourage the evolution of candidacy criteria.