Cochlear implantation outcomes in patients with far advanced otosclerosis

Endoscopic-Assisted Cochlear Implantation in Far Advanced Otosclerosis

OBJECTIVES

To evaluate the effectiveness of cochlear implantation (CI) in case of far advanced otosclerosis and to evaluate the value of using intraoperative otoendoscopy to facilitate the identification of the round window membrane and the scala tympani without the need to remove the posterior canal wall or to perform a subtotal petrosectomy.

STUDY DESIGN

Retrospective case-series study.

SETTING

Tertiary academic CI center.

PATIENTS AND METHODS

This study was conducted on patients with far advanced otosclerosis who underwent endoscopic-assisted CI between January 2010 and June 2020 at the same CI center. The minimum follow-up period was 2 years after surgery.

RESULTS

Fourteen patients were included in the study. Ten patients had undergone a previous stapedotomy. Electrode insertion in the scala tympani was successfully accomplished in all cases included in the study. There was a statistically significant improvement in pure-tone average and speech discrimination scores in all cases of the study group (p < 0.0001). There were no statistically significant differences in postoperative pure-tone average or speech discrimination scores between cases with and without cochlear ossification or between cases with and without a previous stapedotomy (p > 0.05).

CONCLUSION

Endoscopic-assisted CI is an effective option for hearing restoration in patients with far advanced otosclerosis. Otoendoscopy can facilitate visualization and access to the scala tympani without the need to remove the posterior canal wall or to perform a subtotal petrosectomy.

Stapedotomy Versus Cochlear Implantation for Far Advanced Otosclerosis: Insights From a Patient With Matched Preoperative and Postoperative Function

OBJECTIVE

To examine patient preference after stapedotomy versus cochlear implantation in a unique case of a patient with symmetrical profound mixed hearing loss and similar postoperative speech perception improvement.

PATIENTS

An adult patient with bilateral symmetrical far advanced otosclerosis, with profound mixed hearing loss.

INTERVENTION

Stapedotomy in the left ear, cochlear implantation in the right ear.

MAIN OUTCOME MEASURE

Performance on behavioral audiometry, and subjective report of hearing and intervention preference.

RESULTS

A patient successfully underwent left stapedotomy and subsequent cochlear implantation on the right side, per patient preference. Preoperative audiometric characteristics were similar between ears (pure-tone average [PTA] [R: 114; L: 113 dB]; word recognition score [WRS]: 22%). Postprocedural audiometry demonstrated significant improvement after stapedotomy (PTA: 59 dB, WRS: 75%) and from cochlear implant (PTA: 20 dB, WRS: 60%). The patient subjectively reported a preference for the cochlear implant ear despite having substantial gains from stapedotomy. A nuanced discussion highlighting potentially overlooked benefits of cochlear implants in far advanced otosclerosis is conducted.

CONCLUSION

In comparison with stapedotomy and hearing aids, cochlear implantation generally permits greater access to sound among patients with far advanced otosclerosis. Though the cochlear implant literature mainly focuses on speech perception outcomes, an underappreciated benefit of cochlear implantation is the high likelihood of achieving "normal" sound levels across the audiogram.

Cochlear implantation in advanced otosclerosis: utility of pre-operative radiological assessment in predicting intra-operative difficulty and final electrode position

OBJECTIVE

This study aimed to determine if pre-operative radiological scoring can reliably predict intra-operative difficulty and final cochlear electrode position in patients with advanced otosclerosis.

METHOD

A retrospective cohort study of advanced otosclerosis patients who underwent cochlear implantation (n = 48, 52 ears) was compared with a larger cohort of post-lingually deaf adult patients (n = 1414) with bilateral hearing loss and normal cochlear anatomy. Pre-operative imaging for advanced otosclerosis patients and final electrode position were scored and correlated with intra-operative difficulty and speech outcomes.

RESULTS

Advanced otosclerosis patients benefit significantly from cochlear implantation. Mean duration of deafness was longer in the advanced otosclerosis group (19.5 vs 14.3 years; p < 0.05).

CONCLUSION

Anatomical changes in advanced otosclerosis can result in increased difficulty of surgery. Evidence of pre-operative cochlear luminal changes was associated with intra-operative difficult insertion and final non-scala tympani position. Nearly all electrodes implanted in the advanced otosclerosis cohort were peri-modiolar. No reports of facial nerve stimulation were observed.

Stapes Surgery in Far-Advanced Otosclerosis

INTRODUCTION

Surgical treatment of patients with far-advanced otosclerosis (FAO) has not yet been standardized. Patients with FAO are the candidates for stapes surgery or cochlear implant (CI). Although many surgeons consider stapes surgery as the first choice, other authors prefer CI because of the excellent hearing results.

OBJECTIVE

The authors discuss their experience in the treatment of patients with FAO, potentially candidates for CI, who underwent stapedotomy.

MATERIALS AND METHODS

Eleven adult patients with FAO underwent stapedotomy from 2006 to 2016. Pure-tone average (PTA) between 0.5-1-2-3 kHz and speech perception test with hearing aids were determined before and after stapedotomy.

RESULTS

The results show a statistically significant improvement in air condition threshold (PTA) and satisfactory results with regard to speech recognition in 9 (81.8%) cases. Postoperative results are not influenced by the type of stapedotomy prosthesis employed and do not change during follow-up (3 years).

CONCLUSIONS

The authors suggest first performing stapes surgery in patients with FAO and reserving CI in case of failure.

Brazilian Society of Otology task force - Otosclerosis: evaluation and treatment

OBJECTIVES

To review and provide evidence-based recommendations for the diagnosis and treatment of otosclerosis.

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 otosclerosis 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 and radiologic; 2) Treatment - hearing AIDS, pharmacological therapy, stapes surgery, and implantable devices - bone-anchored devices, active middle ear implants, and Cochlear Implants (CI).

CONCLUSIONS

The pathophysiology of otosclerosis has not yet been fully elucidated, but environmental factors and unidentified genes are likely to play a significant role in it. Women with otosclerosis are not at increased risk of worsening clinical condition due to the use of contraceptives or during pregnancy. Drug treatment has shown little benefit. If the patient does not want to undergo stapedotomy, the use of hearing aids is well indicated. Implantable systems should be indicated only in rare cases, and the CI should be indicated in cases of profound deafness.

The Pathogenesis of Cytomegalovirus and Other Viruses Associated with Hearing Loss: Recent Updates

Virus infection is one of the most common etiologies of hearing loss. Hearing loss associated with viral infection can be unilateral or bilateral, mild or severe, sudden or progressive, and permanent or recoverable. Many viruses cause hearing loss in adults and children; however, the pathogenesis of hearing loss caused by viral infection is not fully understood. This review describes cytomegalovirus, the most common virus causing hearing loss, and other reported hearing loss-related viruses. We hope to provide a detailed description of pathogenic characteristics and research progress on pathology, hearing phenotypes, possible associated mechanisms, treatment, and prevention measures. This review aims to provide diagnostic and treatment assistance to clinical workers.

Treatment of Far-Advanced Otosclerosis: Stapedotomy Plus Hearing Aids to Maximize the Recovery of Auditory Function-A Retrospective Case Series

Far-advanced otosclerosis (FAO) refers to severe otosclerosis with scarce auditory functions. The identification of the best method to correctly listen to sound and speech has a large impact on patients' quality of life. We retrospectively analyzed the auditory function of 15 patients affected by FAO who were treated with stapedectomy plus hearing aids independent of the severity of their auditory deficit before surgery. The combination of surgery and hearing aids allowed excellent recovery of the perception of pure tone sounds and speech. Four patients, because of poor auditory thresholds, needed a cochlear implant after stapedectomy. Despite being based on a small sample of patients, our results suggest that stapedotomy plus hearing aids could improve the auditory capacities of patients with FAO independent of their auditory thresholds at T0. The careful selection of patients is fundamental to obtain the best outcomes.

Comparison of the efficacy of cochlear implantation and stapes surgery in far advanced otosclerosis: a meta-analysis study

OBJECTIVE

This study is to compare the hearing outcomes and complications of stapes surgery and cochlear implantation (CI) in patients with far-advanced otosclerosis (FAO).

DATA SOURCES

A comprehensive electronic search of PubMed/MEDLINE, Scopus, Web of science and Cochrane Library was conducted in June 2021 for articles in the literature till this year.

STUDY SELECTION

Studies are published in English language, conducted on human subjects, concerned with comparison of CI and stapes surgery in the management of FAO, not Laboratory study and not Opinion study. The current review followed the guidelines of preferred reporting items for systematic reviews and meta-analysis statement 2009 (PRISMA).

DATA EXTRACTION

Twenty-six studies were included with 334 patients in CI group and 241 patients in stapes surgery group. Comparison between both groups was done in terms of postoperative complications, audiological outcomes, rete of revision surgery and patients' satisfaction rate.

RESULTS

Postoperative complications rate was significantly lower in CI (13.6%) than stapes surgery (18.6%). CI had a significantly lower rate of revision surgery (8.1%) than stapes surgery (16.4%). CI had a better mean for pure tone average (29.1 dB) than stapedectomy (52.3 dB) while stapes surgery had a higher mean for recognition of monosyllables and disyllables than CI. CI had significantly higher satisfaction rate than stapes surgery.

CONCLUSION

Both Stapes surgery and CI are reliable treatment options for FAO with close success rates. Statistics of CI are greater than stapes surgery and CI has a consistent improvement in audiometric outcomes in comparison to stapes surgery.

Cochlear re-implantation with the use of multi-mode grounding associated with anodic monophasic pulses to manage abnormal facial nerve stimulation

Objectives: To investigate the outcomes of cochlear re-implantation using multi-mode grounding stimulation associated with anodic monophasic pulses to manage abnormal facial nerve stimulation (AFNS) in cochlear implant (CI) recipients. Methods: Retrospective case report. An adult CI recipient with severe AFNS and decrease in auditory performance was re-implanted with a new CI device to change the pulse shape and stimulation mode. Patient's speech perception scores and AFNS were compared before and after cochlear re-implantation, using monopolar stimulation associated with cathodic biphasic pulses and multi-mode stimulation mode associated to anodic monophasic pulses, respectively. The insertion depth angle and the electrode-nerve distances were also investigated, before and after cochlear re-implantation. Results: AFNS was resolved, and the speech recognition scores rapidly increased in the first year after cochlear re-implantation while remaining stable. After cochlear re-implantation, the e15 and e20 electrodes showed shorter electrode-nerve distances compared to their correspondent e4 and e7 electrodes, which induced AFNS in the first implantation. Conclusions: Cochlear re-implantation with multi-mode grounding stimulation associated with anodic monophasic pulses was an effective strategy for managing AFNS. The patient's speech perception scores rapidly improved and AFNS was not detected four years after cochlear re-implantation.

Facial nerve stimulation in adult cochlear implant recipients with far advanced otosclerosis

Objectives

The objective of this study was to predict occurrence of facial nerve stimulation (FNS) in cochlear implanted patients for far-advanced otosclerosis (FAO) by correlating preoperative computed tomography (CT)-scan data to FNS and to evaluate FNS impact on hearing outcomes.

Methods

Retrospective analysis on 91 ears (76 patients) implanted for FAO. Electrodes were straight (50%) or perimodiolar (50%). Demographic data, extension of otosclerosis on preoperative CT scan, occurrence of FNS, and speech performance were analyzed.

Results

Prevalence of FNS was 21% (19 ears). FNS appeared during the first month (21%), 1-6 months (26%), 6-12 months (21%), and over 1 year (32%) postimplantation. Cumulative incidence of FNS at 15 years was 33% (95% CI = [14-47%]). Extension of otosclerotic lesions on preimplantation CT-scan was more severe in FNS ears compared to No-FNS (p < .05): for Stage III, 13/19 (68%) and 18/72 (25%) ears for FNS and No-FNS groups, respectively (p < .05). Location of otosclerotic lesions relative to the facial nerve canal was similar whatever the presence or not of FNS. Electrode array had no impact on FNS occurrence. At 1 year post-implantation, duration of profound hearing loss (≥5 years) and previous stapedotomy were negatively associated with speech performance. FNS did not impact hearing outcomes, despite a lower percentage of activated electrodes (p < .01) in the FNS group. Nevertheless, FNS were associated with a decrease of speech performance both in quiet (p < .001) and in noise (p < .05).

Conclusion

Cochlear implanted patients for FAO are at greater risk of developing FNS affecting speech performance over time, probably due to a higher percentage of deactivated electrodes. High resolution CT-scan is an essential tool allowing FNS prediction but not time of onset.

Level of evidence

2b, Laryngoscope Investigative Otolaryngology, 2022.

Cochlear Implantation in Far Advanced Otosclerosis: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate speech outcomes and facial nerve stimulation (FNS) rates in patients with far advanced otosclerosis (FAO) after cochlear implantation.

METHODS

A systematic review was performed using standardized methodology of Medline, EMBASE, PubMed, Cochrane, and Web of Science databases. Studies were included if adults with FAO underwent cochlear implantation. Exclusion criteria included concurrent otologic history (e.g., Meniere's disease, superior canal dehiscence), non-English-speaking implant users, case reports, abstracts, and letters/commentaries. Bias was assessed using the Newcastle-Ottawa Scale for cohort studies and the National Institute of Health Scale for case series. The primary outcome measure was speech discrimination and the secondary outcomes were rates of partial insertion and FNS.

RESULTS

Twenty-seven studies evaluated cochlear implantation in FAO. Due to the heterogeneity of testing methods, statistical pooling of speech discrimination was not feasible, but qualitative synthesis indicated a positive effect of implantation. Pooled rates of FNS were 18% (95% confidence interval, CI 12%-27%) and the rate of partial insertion was 10% (95% CI 7%-15%).

CONCLUSION

Cochlear implantation in FAO demonstrates significant gains in speech discrimination scores with higher rates of FNS and partial insertion. Laryngoscope, 2022.

Cochlear Implant Outcomes in Patients With Otosclerosis: A Systematic Review

OBJECTIVE

This study aimed to establish hearing outcomes after cochlear implantation in patients with otosclerosis.

MATERIALS AND METHODS

We conducted a systematic review and narrative synthesis. Databases searched were as follows: MEDLINE, PubMed, Embase, Web of Science, Cochrane Collection, and ClinicalTrials.gov . No limits were placed on language or year of publication. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

RESULTS

Searches identified 474 abstracts and 180 full texts, with 68 studies meeting the inclusion criteria and reporting outcomes in a minimum of 481 patients with at least 516 implants. Patient-reported outcome measures (PROMs) were reported in five studies involving 51 patients. Intraoperative adverse events/surgical approach details and preoperative radiological assessment were reported in 46 and 38 studies, respectively. The methodological quality of included studies was modest, predominantly consisting of case reports and noncontrolled case series with small numbers of patients. Most studies were Oxford Centre for Evidence Based Medicine grade IV.

DISCUSSION

Access to good rehabilitation support is essential to achieving the good hearing outcomes and PROMs that can be expected by 12 months after implantation in most cases. There was a significant association between the radiological severity of otosclerosis and an increase in surgical and postoperative complications. Postoperative facial nerve stimulation can occur and may require deactivation of electrodes and subsequent hearing detriment.

CONCLUSIONS

Hearing outcomes are typically good, but patients should be counseled on associated surgical complications that may compromise hearing. Modern diagnostic techniques may help to identify potentially difficult cases to aid operative planning and patient counseling. Further work is needed to characterize PROMs in this population.

Cochlear Implantation in Advanced Otosclerosis: Pitfalls and Successes

Purpose of Review

This review will highlight recent outcome-based evidence guiding decision making for cochlear implantation in advanced otosclerosis, related complications, and technical surgical considerations in otosclerosis and the obstructed cochlea.

Recent Findings

Cochlear implantation in advanced otosclerosis results in consistent, excellent auditory outcomes with improvement in both objective speech recognition scores and subjective quality of life measures. Facial nerve stimulation may occur at higher rates in otosclerosis cochlear implant recipients. Cochlear implantation in the setting of luminal obstruction in osteosclerotic patients may be managed with altered surgical technique to achieve successful auditory improvements. Pre-operative imaging with high resolution CT or MRI may help anticipate intraoperative challenges and post-operative complications in cochlear implantation.

Summary

Cochlear implantation is an established, successful treatment for profound hearing loss in advanced otosclerosis. Surgeon knowledge of outcomes, complications, and potential surgical challenges is important to appropriately counsel patients regarding auditory rehabilitation options in advanced otosclerosis.

Cochlear implantation outcomes in patients with otosclerosis: a single-centre study

PURPOSE

To analyse surgical and auditory outcomes after cochlear implantation in otosclerosis and to compare them to the outcomes in patients with post-lingual hearing loss with different aetiology.

METHODS

Medical records of 17 subjects (22 ears) diagnosed with otosclerosis were compared to 21 controls (25 ears) matched by age, sex, duration of hearing loss and experience with cochlear implant in years. Demographic characteristics, surgical complications, facial nerve stimulation, number and reason for deactivated electrodes and auditory outcome (monosyllabic word score) were analysed. The auditory outcome was further evaluated according to the anatomical localisation of the otosclerotic lesions (grades) and compared between patients with active and deactivated electrodes.

RESULTS

Otosclerotic patients showed similar surgical outcome in comparison to the controls. A low frequency (13.6%) of facial nerve stimulation was observed in otosclerosis. A significantly higher (p = 0.014) number of deactivated electrodes (4.3%) in subjects with otosclerosis in comparison to non-otosclerosis patients (1.6%) was found. A trend of less speech discrimination of monosyllabic words (65%) in otosclerosis than in non-otosclerosis patients (80%) (p = 0.109) and no difference in the postoperative auditory assessment with regard to the disease grade and electrode disabling was found.

CONCLUSIONS

Cochlear implantation by otosclerosis provides excellent auditory outcome with a low rate of surgical complications. Alteration in fitting strategy as electrodes disabling is frequently needed to overcome complications as incomplete insertion, facial nerve stimulation and poor sound quality.

Cochlear implantation among patients with otosclerosis: a systematic review of clinical characteristics and outcomes

PURPOSE

There have been considerable advancements in cochlear implants in different clinical scenarios; however, their use in patients with otosclerosis remains challenging. This review aimed to investigate the surgical and clinical outcomes of cochlear implantation in patients with otosclerosis.

METHODS

An electronic literature search was performed using four main databases through February 2021 to identify original studies of cochlear implantation in patients with otosclerosis for inclusion in this systematic review. The study protocol was registered with the Prospectively Registered Systematic Reviews and Meta-analyses (reference number: CRD42021234753).

RESULTS

A total of 23 studies including 3162 patients were enrolled. Of these patients, only 392 had otosclerosis and underwent cochlear implantation. The duration of deafness was reported in only eight studies, extending up to 50 years. Far-advanced otosclerosis was observed in 153 patients. A total of 56 patients used hearing aids. Stapedectomy and stapedotomy were performed in 118 and 63 patients, respectively. In three studies, the temporary success of stapedectomy and stapedotomy was 6 (43%) and 5 (71%) patients, respectively. Computed tomography was used as a preoperative assessment tool in most studies (n = 14, 60.9%). Incomplete implant insertion occurred in 17 patients, while facial nerve stimulation occurred in 36 patients after implantation.

CONCLUSION

Cochlear implantation is a relatively safe modality that can provide promising audiological outcomes in patients with otosclerosis. However, several factors, including cochlear ossification, duration of deafness, and previous operations, can affect its outcomes. Further studies with a larger sample population are recommended.

OTOPLAN in Cochlear Implantation for Far-advanced Otosclerosis

AIM

To evaluate OTOPLAN software in the surgical planning of far-advanced otosclerosis (FAO) candidates to cochlear implant (CI) were considered. We aimed to preliminarily investigate if this software could influence the electrode length choice, or predict surgical difficulties.

METHODS

We reviewed the outcome of five consecutive FAO patients that underwent unilateral CI. OTOPLAN was used to evaluate preoperative computed tomography imaging. A comparison was made with historical data (eight FAO patients).

RESULTS

The mean cochlear duct length estimated by OTOPLAN was 32.4 mm. Evaluating OTOPLAN reconstructed images, we ruled out cochlear lumen fibrosis/ossification in three FAO patients and the longest electrodes according to cochlear dimensions were preferred. We disclosed fibrosis in the middle and apical turns of two patients. These findings allowed us to change surgical plans, choosing a shorter electrode (24 and 28 mm instead of 31 mm) to avoid incomplete insertion due to cochlear fibrosis. OTOPLAN reconstructed images identified preoperatively the two patients with round window niche ossification that required additional drilling during surgery. In the present series, we experienced no incomplete insertion. In two cases out of eight historical FAO patients, array insertion (24 mm) was incomplete. One years after unilateral CI, the mean speech reception threshold and disyllabic word recognition score of the five considered FAO patients were 36 dB and 94%, respectively (39 dB and 84% for the eight historical patients). There was no facial nerve stimulation or any other complication during the 1-year follow-up.

CONCLUSION

According to our preliminary results, OTOPLAN was useful for the appropriate choice of array length.

Factors Influencing Aberrant Facial Nerve Stimulation Following Cochlear Implantation: A Systematic Review and Meta-analysis

OBJECTIVE

The purpose of this study was to systematically evaluate the literature to evaluate the rate of and associated factors with aberrant facial nerve stimulation (AFNS) following cochlear implantation. Additionally, management strategies for AFNS were assessed.

DATA SOURCES

A systematic search was performed in PubMed, Cochrane Database of Systematic Reviews, and Web of Science to identify peer reviewed research.

STUDY SELECTION

Eligible studies were those containing peer-reviewed research in English addressing AFNS following cochlear implantation. Studies with paired data were included in the meta-analysis.

DATA EXTRACTION

Three investigators independently reviewed all articles and extracted data. Bias was assessed using the National Institutes of Health Study Quality Assessment Tool.

DATA SYNTHESIS

Thirty-seven articles were included, representing 5,694 patients. The overall reported AFNS rate was 5.6% (range, 0.68-43%). Array type demonstrated a significant association with AFNS with lateral wall electrodes having a higher odds ratio than perimodiolar electrodes (odds ratio [OR] = 3.92, 95% confidence interval [CI] 1.46-10.47, p = 0.01). CI recipients with otosclerosis were also more likely to experience AFNS compared with non-otosclerosis pathology (OR = 13.73, 95% CI 3.57-52.78, p < 0.01). Patients with cochlear malformations had an overall AFNS rate of 28% (range, 5.3-43%) and those with otosclerosis had an overall rate of 26% (range, 6.25-75%). Reprogramming with or without electrode deactivation was successful for AFNS elimination. Four patients of 3,015 required explantation.

CONCLUSION

Array type and underlying cochlear pathology are associated with AFNS and implant reprogramming is an overall successful management strategy. Further research is needed to elucidate mechanism of AFNS and develop management strategies that limit impact on hearing outcomes.

Evaluation of computed tomography parameters in patients with facial nerve stimulation post-cochlear implantation

PURPOSE

To compare the preoperative computed tomography (CT) parameters, including the thickness and density of the bone separating the upper basal turn of the cochlea (UBTC) and the labyrinthine segment of the facial nerve (LSFN), in patients with and without facial nerve stimulation (FNS) in post-cochlear implants (CI).

METHODS

A retrospective case review of 1700 CI recipients in a tertiary referral center between January 2010 and January 2020 was performed; out of the 35 recipients who were found to have FNS, 29 were included in the study. The control group comprised the same number of randomly selected patients. CT parameters of the patients were measured independently by three fellowship-trained neuro-otologists blinded to the postoperative status of the patients. Thickness in axial and coronal views and density of the bone separating the UBTC and the LSFN were measured.

RESULT

There was satisfactory agreement between the readings of the three reviewers. The distances (in mm) between the UBTC and LSFN obtained from the coronal (0.43 ± 0.24 vs. 0.63 ± 0.2) and axial (0.42 ± 0.25 vs. 0.6 ± 0.18) views were statistically lower in the FNS group (p = 0.001 and 0.005, respectively). The density (in HU) of the bony partition was also statistically lower in the FNS group (1038 ± 821 vs. 1409 ± 519; p = 0.029).

CONCLUSION

Patients who experienced FNS postoperatively had significantly lower distance and bone density between the UBTC and the LSFN. This finding can help surgeons in preoperative planning in an attempt to decrease the occurrence of FNS.

Surgical considerations and audiological results of cochlear implantation in patients with otosclerosis

Background/aim

To emphasize the role of cochlear implantation (CI) in the auditory rehabilitation of patients with otosclerosis (OS) and share our surgical experiences on this rare group of patients.

Materials and methods

Retrospective analysis of the patients who have a diagnosis of otosclerosis and implanted between January 1998–May 2019 was performed. Preoperative and postoperative clinical, radiological, audiological and surgical findings are presented.

Results

Among 2195 patients who have been implanted in our institution, 12 (0.54%) met the diagnostic criteria of OS according to their preoperative (clinical, radiological, audiological) and peroperative (surgical) findings. Electrode insertion was performed via “round window membrane and cochleostomy” in 8 and 4 patients, respectively. No major complications occured. All patients showed satisfactory performances by means of audiometric scores postoperatively. Nonauditory stimulation (NAS) which manifested as “facial twitching” was a challenging problem in one patient during the surgery and subsided after the operation.

Conclusion

Our experience on CI in patients with OS revealed that the implantation was a relatively safe procedure and had satisfactory impact on audiological performances.

Cochlear implantation in far-advanced otosclerosis: hearing results and complications

Severe forms of otosclerosis known as far-advanced otosclerosis (FAO) can lead to severe to profound sensorineural hearing loss and can justify cochlear implantation. Because of the pathophysiology of otosclerosis, patients implanted for FAO may experience an increased rate of complications, such as facial nerve stimulation or electrode dislocation, and may have poorer hearing outcomes than expected. This retrospective study aimed to compare cochlear implantation hearing outcomes, surgical difficulties and complications in FAO patients versus non-FAO patients. Moreover, we evaluated whether high resolution computed tomography (CT scan) findings were predictive of perioperative problems, complications and hearing outcomes. FAO patients were diagnosed based on medical history, examination and CT scan. Thirty-five ears from FAO patients were compared to 38 control ears. Audiometric results were assessed at least 12 months after implantation by pure tone average, speech reception threshold, monosyllabic and disyllabic word recognition score (WRS) and Central Institute for the Deaf (CID) sentences test. Complications and surgical difficulties were compiled. CT scan findings were categorised within 3 grades of otosclerotic extension. No significant difference was found between FAO and non-FAO hearing outcomes, except that monosyllabic WRS were lower for FAO patients, especially those who underwent previous stapedotomy. Facial nerve symptomatology occurred in 8.6% of FAO patients; among these, one required explantation-reimplantation surgery. 86% of FAO implanted patients had retrofenestral extension on CT. These were associated with poorer disyllabic WRS (51% vs 68%, p < 0.05) than those with only fenestral involvement. Although not significant, high grade of severity on CT tended to be associated with surgical difficulties and complications. Cochlear implantation in FAO patients is an effective treatment technique. Though the overall complication rate is low, it tends to be higher in cases of severe extension on CT. Patient counselling should be adjusted accordingly.

Cochlear Implant Users with Otosclerosis: Are Hearing and Quality of Life Outcomes Worse than in Cochlear Implant Users without Otosclerosis?

Background: The otosclerotic process may influence the performance of the cochlear implant (CI). Difficulty in inserting the electrode array due to potential ossification of the cochlea, facial nerve stimulation, and instability of the results are potential challenges for the CI team. Objectives: To evaluate hearing results and subjective outcomes of CI users with otosclerosis and to compare them with those of CI users without otosclerosis. Method: Retrospective review of 239 adults with bilateral profound postlingual deafness who underwent unilateral cochlear implantation between 1992 and 2017. Hearing and speech understanding were assessed via pure-tone audiometry and speech perception tests. Subjective outcomes were assessed via the Nijmegen Cochlear Implant Questionnaire (NCIQ), the Glasgow Benefit Inventory (GBI), and the Hearing Implant Sound Quality Index (HISQUI19) at 6 months, 12 months, and at the last follow-up. Results: Subjects were 22 CI users with otosclerosis and 217 without otosclerosis. Both groups had a similar duration of deafness and age at CI implantation. Results did not significantly differ according to group: no significant intergroup difference was found regarding the frequency of complete electrode insertion, facial stimulation, reimplantation, or PTA4 scores at the last follow-up. Regarding speech perception, no significant intergroup difference was found on any test or at any interval. Further, subjective outcomes, as measured by the GBI, NCIQ, and HISQUI19, did not significantly differ between groups. Conclusions: Adults with otosclerosis and profound hearing loss derive significant benefit from CI use. Audiological and self-reported outcomes are not significantly different from that of other CI users with postlingual deafness.

Can Preoperative CT Scans Be Used to Predict Facial Nerve Stimulation Following CI?

OBJECTIVES

1) To determine the ability of preoperative computed tomography (CT) to predict facial nerve stimulation (FNS) after cochlear implantation (CI). 2) To recognize the limitations of CT in predicting FNS.

STUDY DESIGN

Patient control study.

SETTING

Tertiary care academic medical center.

SUBJECTS

Adult patients with CI from 2003 to 2015.

METHODS

Patients with severe FNS (n = 4) were compared with randomly selected CI patients (n = 28). Three blinded reviewers evaluated preoperative temporal bone CT scans to measure the distance from the labyrinthine segment of the facial nerve to the basal turn of the cochlea and attempted to predict whether or not the subject had FNS after CI.

RESULTS

In total, 32 CT scans were evaluated representing 49 ears that underwent CI.The distances (mm) measured from the labyrinthine segment of the facial nerve to the basal turn of the cochlea in both the axial (0.3 ± 0.3 versus 0.6 ± 0.3) and coronal (0.4 ± 0.2 versus 0.6 ± 0.2) orientation were significantly different between the two groups (p = 0.0001 and p = 0.0034) respectively. The intraclass correlation coefficient demonstrated good (K > 0.7) reviewer correlation in both the reviewers' measurements and predictions. The sensitivity, specificity, positive predictive value, and negative predictive value for preoperative CT scans to predict FNS were 38.5, 85.1, 19.2, and 93.8% respectively. The reviewers were 23% accurate in predicting FNS.

CONCLUSION

Based on a blinded retrospective patient-control study, CT scan measurements show a significantly reduced distance between the labyrinthine facial nerve and the basal turn of the cochlea in patients with FNS. However, it is difficult to predict who will have FNS based on these measurements.

Cochlear implantation in patients with otosclerosis of the otic capsule

OBJECTIVE

To evaluate outcomes of cochlear implantation of patients with otosclerosis of the otic capsule.

STUDY DESIGN

A retrospective case series of 6 patients (7 ears).

PATIENTS

6 patients (7 ears), 5 patients with severe to profound sensorineural hearing loss; 1 patient with mild to profound sensorineural hearing loss, with radiologic evidence of otosclerosis. All patients were adult males, with or without history of stapes surgery.

INTERVENTION

Cochlear implantation of 7 ears. 5 patients with severe to profound sensorineural hearing loss received the Nucleus Contour Advance peri-modiolar electrode array with binaural implantation performed in one patient. One patient with mild to profound sensorineural hearing loss received a Cochlear® Nucleus Hybrid L24 device.

METHODS

Preoperative temporal bone CT, audiometric and speech perception testing scores were reviewed, confirming presence of otosclerosis of the cochlea as well as cochlear implant candidacy. Speech perception testing included CNC words, HINT sentences and AZ Bio scores to measure hearing outcomes post implantation.

RESULTS

All recipients of the contour advance device had a significant improvement in hearing at both 3 and 6month follow up.The hybrid device recipient experienced loss of residual hearing in the implanted ear without improvement at 3months and mild improvement at 6months.

CONCLUSION

Cochlear implantation has proven to be effective in the treatment of patients with sensorineural hearing loss, including those with otosclerosis of the cochlea.Hybrid candidacy in the setting of otosclerosis of the cochlea may require consideration of alternative electrode devices, most likely a peri-modiolar device.

Intracochlear Drug Delivery Through the Oval Window in Fresh Cadaveric Human Temporal Bones

HYPOTHESIS

Drug delivered to the oval window can diffuse to the apex of the human cochlea.

BACKGROUND

We have previously demonstrated that zoledronate, a nitrogen-containing bisphosphonate, can arrest the sensorineural hearing loss in cochlear otosclerosis. We have also shown that, in animals, delivery of bisphosphonate into the cochlea can dramatically increase delivery efficiency. Intracochlear drug delivery has the potential to increase local concentration of drug while decreasing the risk of systemic toxicity. In the present study, a fluorescently labeled bisphosphonate compound (6-FAM-ZOL) was introduced into the human cochlea through the oval window and its distribution within the temporal bone was quantified.

METHODS

In three fresh human temporal bones, we introduced 6-FAM-ZOL via the oval window. We compared these specimens to control specimens treated with artificial perilymph alone. Specimens were then processed, embedded into methyl methacrylate, and ground to the mid-modiolar axis. We quantified the fluorescence in confocal images.

RESULTS

We found 6-FAM-ZOL to be distributed up to the apical cochlear turn. In specimens treated with 6-FAM-ZOL, we identified a strong baso-apical gradient of fluorescent signal along the lateral cochlear wall and the modiolus both in the scala vestibuli and in the scala tympani.

CONCLUSION

Bisphosphonate introduced via the oval window in the human cochlea can be delivered up to the apical cochlear turn. Interscalar communication is likely to play an important role in determining patterns of drug delivery in the inner ear.

Inner Ear Active Hearing Device in Non-Otosclerotic, Severe, Mixed Hearing Loss

OBJECTIVE

To verify the efficacy of a powerful active hearing device in a patient different from far-advanced otosclerosis, specifically when the stapes footplate is mobile.

PATIENT

A patient with severe-to-profound mixed hearing loss, who was not benefiting from the use of a conventional hearing aid, was selected for an inner ear active implant. This was justified by a bone conductive threshold above 60 dB, which had discouraged any other rehabilitative solutions such as a bone conductive implant, or an active middle ear implant (AMEI).

INTERVENTION

The hearing device was surgically applied using a combined transmastoid/transcanal approach. During surgery, a mobile stapes were found and was perforated for the insertion of a piston prosthesis, crimped on the new-incus of the device.

MAIN OUTCOME MEASURE

The bone conduction threshold was assessed postoperatively to identify any possible surgery-related hearing deterioration. Pure tone audiometry was conducted in a sound field, and a speech reception threshold test was performed with the contralateral ear masked. The hearing outcome was assessed soon after the implant activation (6 weeks after surgery), and 6 months after surgery.

RESULTS

Upon activation of the device, a PTA of 45 dB was obtained (at 0.5, 1, 2 and 4 kHz). At 6 months after surgery, the speech discrimination score reached 90% at 80 dB SPL.

CONCLUSION

The application of the Codacs device has shown to be compatible with a mobile stapes footplate, as demonstrated in this report. The footplate perforation did not cause any further hearing deterioration, and has allowed to achieve a favorable auditory outcome.

Non-Ototoxic Local Delivery of Bisphosphonate to the Mammalian Cochlea

HYPOTHESIS

Local delivery of bisphosphonates results in superior localization of these compounds for the treatment of cochlear otosclerosis, without ototoxicity.

BACKGROUND

Otosclerosis is a common disorder of abnormal bone remodeling within the human otic capsule. It is a frequent cause of conductive hearing loss from stapes fixation. Large lesions that penetrate the cochlear endosteum and injure the spiral ligament result in sensorineural hearing loss. Nitrogen-containing bisphosphonates (e.g., zoledronate) are potent inhibitors of bone remodeling with proven efficacy in the treatment of metabolic bone diseases, including otosclerosis. Local delivery to the cochlea may allow for improved drug targeting, higher local concentrations, and the avoidance of systemic complications. In this study, we use a fluorescently labeled bisphosphonate compound (6-FAM-ZOL) to determine drug localization and concentration within the otic capsule. Various methods for delivery are compared. Ototoxicity is evaluated by auditory brainstem responses and distortion product otoacoustic emissions.

METHODS

6-FAM-ZOL was administered to guinea pigs via intraperitoneal injection, placement of alginate beads onto the round window membrane, or microfluidic pump infusion via a cochleostomy. Hearing was evaluated. Specimens were embedded into resin blocks, ground to a mid-modiolar section, and quantitatively imaged using fluorescence microscopy.

RESULTS

There was a dose-dependent increase in fluorescent signal after systemic 6-FAM-ZOL treatment. Local delivery via the round window membrane or a cochleostomy increased delivery efficiency. No significant ototoxicity was observed after either systemic or local 6-FAM-ZOL delivery.

CONCLUSION

These findings establish important preclinical parameters for the treatment of cochlear otosclerosis in humans.

Cochlear implantation outcomes in advanced otosclerosis

INTRODUCTION

Several studies support the use of cochlear implants (CI) in far-advanced otosclerosis (FAO).

MATERIAL AND METHODS

We compared our results of CI in patients with FAO and unknown origin hearing loss (UOHL) and our incidence of facial electrical stimulation and difficult insertion of the electrode bundle up to 3 to 5 years from surgery.

RESULTS

We found 17 patients with CI in FAO and UOHL. FAO patients achieved better results on the pure tone average (PTA) and recognition of monosyllables by GEE test (p=0.022; p=0.006), and particularly at 1 year on the PTA (p=0.002), at 6 months and a year in monosyllables (p=0.002; p=0.001), and at 6 months in disyllables (p=0.004). There were no differences toward complications.

CONCLUSION

In our experience, placement of CI in FAO has proven successful, with results comparable to other similar cohorts, and with low complications.

The pathologic basis of facial nerve stimulation in otosclerosis and multi-channel cochlear implantation

HYPOTHESIS

Unintentional electrical stimulation of the facial nerve by cochlear implants occurs when advanced otosclerosis invades the endosteum of both the upper basal turn of the cochlea (UBTC) and the facial nerve canal (FNC) and all the bone between these 2 structures.

BACKGROUND

A complication of cochlear implantation is facial nerve stimulation (FNS) known to be more common in otosclerosis. Otosclerotic involvement of the enchondral bone of the otic capsule results in areas of bone resorption, new bone formation, vascular proliferation, and a connective tissue stroma. This may reduce impedance, shunting current to the facial nerve. The cause of FNS has not been fully elucidated, and remarkable differences in FNS rates have been reported using different types of electrode arrays.

METHODS

Thirteen implanted temporal bones from 11 patients with otosclerosis, 10 with straight, and 3 with perimodiolar electrodes, were histologically processed after death. The data were analyzed using Fisher's exact test.

RESULTS

In the straight electrode group (n = 10), only those subjects with temporal bones showing involvement by otosclerosis of the UBTC and of FNC endosteum and the bone between these 2 structures (n = 4; 40%) showed FNS during life (p = 0.005), which was consistent with the location of problematic electrodes during life. None of the cases in the perimodiolar group had FNS even with endosteal involvement by otosclerosis.

CONCLUSION

FNS is a common complication of cochlear implantation in patients with otosclerosis and occurs most commonly with straight electrode implants where the endosteum of both UBTC and FNC and the intervening bone are otosclerotic.

Viral causes of hearing loss: a review for hearing health professionals

A number of viral infections can cause hearing loss. Hearing loss induced by these viruses can be congenital or acquired, unilateral or bilateral. Certain viral infections can directly damage inner ear structures, others can induce inflammatory responses which then cause this damage, and still others can increase susceptibility or bacterial or fungal infection, leading to hearing loss. Typically, virus-induced hearing loss is sensorineural, although conductive and mixed hearing losses can be seen following infection with certain viruses. Occasionally, recovery of hearing after these infections can occur spontaneously. Most importantly, some of these viral infections can be prevented or treated. For many of these viruses, guidelines for their treatment or prevention have recently been revised. In this review, we outline many of the viruses that cause hearing loss, their epidemiology, course, prevention, and treatment.