Hearing Preservation With the Use of Flex20 and Flex24 Electrodes in Patients With Partial Deafness

Outcomes of attempted hearing preservation after cochlear implantation (HPCI): a prognostic factor (PF) systematic review of the literature

OBJECTIVE

There's a need to highlight prognostic factors (PFs) determining hearing preservation in cochlear implantation (HPCI), as currently there is large variability in outcomes. Given the potential benefits of HPCI, it is important to understand the factors influencing this variation. We apply a novel methodology to outline and assess the accuracy of prognostic factors reporting for HPCI.

DATA SOURCES

A preferred reporting item for systematic reviews and meta-analyses compliant systematic review, searches applied to Medline, EMBASE, and Cochrane.

STUDY SELECTION

The CHARMS-PF tool assessed the strength of PF study designs.

DATA EXTRACTION

The QUIPS tool assessed for risk of bias.

DATA SYNTHESIS AND RESULTS

Ninety-two papers were suitable for data extraction. The domain's preoperative hearing loss, size of the round window opening, round window accessibility, surgical insertion speed and route (Round window or cochleostomy), electrode length and type were identifiable exploratory PFs for HPCI. Overall, the study's heterogeneity and risk of bias precluded reporting by forest plots and meta-analysis.

CONCLUSIONS

Most exploratory PF studies for HPCI are hindered by the risk of bias. This systematic review identifies potential independent PFs which should be measured, and adjusted for, in future confirmatory studies using a multivariate analysis. This would determine the independent prognostic effects associated with HPCI while facilitating prognostic model development and the predict individual HPCI.

Is Partial Deafness Dysphonia Gender Related?

Partial deafness (PD) is a hearing impairment that presents with normal hearing thresholds at low frequencies (up to 1 kHz), and deep hypoacusis at high frequencies. For many years, this type of hypoacusis has not been treated with typical hearing aids because of a low level of speech understanding improvement. Since the first worldwide PD cochlear implantation conducted in 2002, this type of hearing impairment became a subject of research also in the aspect of its influence on the patient's voice.

PURPOSE

This study aimed to examine whether voice disorders accompanying postlingual PD in adults present gender differences.

METHODS

The study group involved 30 patients with post lingual PD (15 females and 15 males) in whom pre existing voice disorders were excluded. Voice samples were recorded and analyzed using Multi-dimensional Voice Program by Kay Pentax.

CONCLUSIONS

The study showed that adults with PD develop voice dysfunctions; however, no major differences between females and males were found.

PURPOSE

This study aimed to examine whether voice disorders accompanying postlingual PD in adults present gender differences. The word gender in the paper is understood as a set of biological attributes associated with physical and physiological features; therefore, is used as the equivalent of sex.

Quality of Voice in Patients With Partial Deafness Before and After Cochlear Implantation

Partial deafness is a condition characterised by normal hearing thresholds in low frequencies and increased hearing thresholds (nearly deafness) for high frequencies. Typical hearing aids are rather of a very limited use in this condition as they do not improve understanding of speech. Patients with partial deafness can be presently treated with cochlear implants, which had not been used before due to the risk of damage of hearing remains by electrode introduced into cochlea. The purpose of our study was an objective and subjective assessment of voice quality in partial deafness patients before and after cochlear implantation. The subjects in this study were 25 post-lingual, bilaterally partially deaf patients, 13 females and 12 males. The reference group composed of 55 normal hearing individuals (28 females and 27 males). The acoustic analysis was performed with a multidimensional voice analysis MDVP (Multi Dimension Voice Program), and the subjective assessment was done with GRBAS scale. Initial analysis of voice changes in partial deafness patients was performed versus normal hearing individuals, then voice parameters were measured and perceptual voice assessment was done before and 9 months after cochlear implantation. Measurements of acoustic voice parameters in partially deaf patients showed changes in most of frequency, amplitude, noise and subharmonic components versus normal hearing control group. The most significant, statistically important changes were observed in fundamental frequency variation (vF0), absolute jitter (Jita), jitter percent (Jitt), amplitude perturbation quotient (APQ), smoothed amplitude perturbation quotient (sAPQ), relative average perturbation (RAP), peak amplitude variation (vAm), relative amplitude modulation (Shim), percent shimmer (%Shim), pitch perturbation quotient (PPQ), smoothed pitched perturbation quotient (sPPQ), degree of subharmonics (DSH), degree of voiceless (DUV), number of subharmonic segments (NSH), noise-to-harmonic ratio (NHR), voice turbulence index (VTI). All patients in the study group were subjects to cochlear implantation. After 9 months objective and subjective assessment of patients` voices were performed again. Statistically important changes were identified in average fundamental frequency variability (vF0), relative amplitude modulation index (ShdB), noise-to-harmonic ratio (NHR), number of subharmonics NSH, degree of subharmonics (DSH) and the degree of voiceless (DUV). Comparison of the objective voice parameters changes after cochlear implantation with subjective, perceptual voice quality assessments leads to observation, that improvement of subjective voice quality after cochlear implantation takes place parallelly with improvement of certain objective acoustic voice parameters and some correlations exist. We found, that G correlates with vF0 and Shim, R correlates with DSH and NSH, B correlates with NSH and NHR, A correlates with DUV. We did not prove correlation of S with any of the objective parameters in our research group. Our study proved, that acoustic and perceptual features of voice in partially deaf adults are different than in normally hearing people and cochlear implantation in partial deafness patients is an effective tool to improve hearing and leads to improvement of the acoustic structure of the voice.Partial deafness is a condition characterised by normal hearing thresholds in low frequencies and increased hearing thresholds (nearly deafness) for high frequencies. Typical hearing aids are rather of a very limited use in this condition as they do not improve understanding of speech. Patients with partial deafness can be presently treated with cochlear implants, which had not been used before due to the risk of damage of hearing remains by electrode introduced into cochlea. The purpose of our study was an objective and subjective assessment of voice quality in partial deafness patients before and after cochlear implantation. The subjects in this study were 25 post-lingual, bilaterally partially deaf patients, 13 females and 12 males. The reference group composed of 55 normal hearing individuals (28 females and 27 males). The acoustic analysis was performed with a multidimensional voice analysis MDVP (Multi Dimension Voice Program), and the subjective assessment was done with GRBAS scale. Initial analysis of voice changes in partial deafness patients was performed versus normal hearing individuals, then voice parameters were measured and perceptual voice assessment was done before and 9 months after cochlear implantation. Measurements of acoustic voice parameters in partially deaf patients showed changes in most of frequency, amplitude, noise and subharmonic components versus normal hearing control group. The most significant, statistically important changes were observed in fundamental frequency variation (vF0), absolute jitter (Jita), jitter percent (Jitt), amplitude perturbation quotient (APQ), smoothed amplitude perturbation quotient (sAPQ), relative average perturbation (RAP), peak amplitude variation (vAm), relative amplitude modulation (Shim), percent shimmer (%Shim), pitch perturbation quotient (PPQ), smoothed pitched perturbation quotient (sPPQ), degree of subharmonics (DSH), degree of voiceless (DUV), number of subharmonic segments (NSH), noise-to-harmonic ratio (NHR), voice turbulence index (VTI). All patients in the study group were subjects to cochlear implantation. After 9 months objective and subjective assessment of patients` voices were performed again. Statistically important changes were identified in average fundamental frequency variability (vF0), relative amplitude modulation index (ShdB), noise-to-harmonic ratio (NHR), number of subharmonics NSH, degree of subharmonics (DSH) and the degree of voiceless (DUV). Comparison of the objective voice parameters changes after cochlear implantation with subjective, perceptual voice quality assessments leads to observation, that improvement of subjective voice quality after cochlear implantation takes place parallelly with improvement of certain objective acoustic voice parameters and some correlations exist. We found, that G correlates with vF0 and Shim, R correlates with DSH and NSH, B correlates with NSH and NHR, A correlates with DUV. We did not prove correlation of S with any of the objective parameters in our research group. Our study proved, that acoustic and perceptual features of voice in partially deaf adults are different than in normally hearing people and cochlear implantation in partial deafness patients is an effective tool to improve hearing and leads to improvement of the acoustic structure of the voice.

Outcomes of Cochlear Implantation Using FLEX26 Electrode: Audiological Results and Quality of Life after 12 Months

INTRODUCTION

The electrode length is one of the many factors impacted on results of cochlear implantation. Among lateral wall flexible electrode arrays the latest one is FLEX26 (MED-EL GmbH, Innsbruck, Austria). The main aim of the study was to evaluate the preservation of residual hearing, the level of speech understanding, and quality of life after cochlear implantation with FLEX26 electrode array.

METHODS

The study was conducted in a tertiary referral centre. Fifty-two patients implanted unilaterally with FLEX26, including 10 EAS patients (electric acoustic stimulation) and 42 ES patients (electric stimulation). The intervention was minimally invasive cochlear implantation via the round window. Pure-tone audiometry (0.125-8 kHz) was performed preoperatively and at 1, 6, and 12 months postoperatively. Twelve-month hearing preservation was established using HEARRING group formula. Quality of life was measured with AQoL-8D (Assessment of Quality of Life-8 Dimensions) pre- and postoperatively.

RESULTS

Residual hearing was preserved in 88.8% EAS patients. Quality of life was significantly better postoperatively in comparison to preoperative period (the effect size for overall quality of life was 0.49). Especially, it increased in relationships and senses dimensions (the effect sizes 0.47 and 0.44, respectively).

CONCLUSION

Preservation of residual hearing can be achieved in the majority of patients implanted with FLEX26. Improvement of quality of life was also documented. FLEX26 seems to be an option for surgeons who seek an electrode providing sufficient cochlear coverage.

Clinical perspective on hearing preservation in cochlear implantation, the University of Iowa experience

Preservation of residual acoustic hearing has emerged as an important concept for those individuals undergoing cochlear implantation with residual low frequency hearing. Acoustic plus electric speech processing improves hearing outcomes in quiet, enables melody recognition, preserves spatial hearing if there is acoustic hearing in both ears and significantly improves hearing in noise. The development of our experience with acoustic plus electric processing is reviewed along with clinical trials and patient outcomes that our team has documented over the past twenty years.

Preliminary study to determine an optimal mode for favorable residual hearing at low frequencies: Full electrical stimulation, electric acoustic stimulation, and electrical complement

Objective

In this prospective study, each subject experienced three modes electric acoustic stimulation (EAS), full electrical stimulation (FES), and electrical complement (EC), and the performance of each mode and subject preference were evaluated.

Methods

Eight ears (seven patients) with successfully preserved residual hearing after cochlear implantation (CI) were included. EAS, FES, and EC programs were set up on each patient's device, and each mode was used for at least 1 h per day for a month. The Speech Intelligibility test, the Speech, Spatial and Qualities of Hearing Scale, and the Hearing in Noise test (HINT) results in each stimulation mode.

Results

The mean monosyllabic word score (EAS: 90.3 ± 4.0; FES: 81.2 ± 16.1) and the mean sentence score (EAS: 98.3 ± 1.7; FES: 95.0 ± 3.0) were significantly higher in the EAS mode than in the FES mode. The mean bisyllabic word score (EAS: 95.6 ± 5.6; EC: 90.1 ± 5.6) was higher in the EAS mode than in the EC mode. In HINT, the signal-to-noise ratios under the noise front (EAS: 4.7 ± 2.5; FES: 7.9 ± 4.4) and noise composite conditions (EAS: 4.2 ± 2.7; FES: 6.6 ± 4.0) were significantly smaller in the EAS mode than in the FES mode. After trials of the three modes, five subjects preferred EAS, one preferred EC, and two preferred FES.

Conclusion

Among the three stimulation modes, EAS produced slightly better results, and subjects generally preferred EAS (five of seven patients, 71.4%). The use of hearing aids before CI was considered an important factor in mode preference. FES may be preferred when CI was performed at a young age and subjects had little experience with hearing aids. However, adults may prefer EC over EAS if there was little or no hearing-aid use before CI.

Magnetic Steering of Robotically Inserted Lateral-wall Cochlear-implant Electrode Arrays Reduces Forces on the Basilar Membrane In Vitro

HYPOTHESIS

Undesirable forces applied to the basilar membrane during surgical insertion of lateral-wall cochlear-implant electrode arrays (EAs) can be reduced via robotic insertion with magnetic steering of the EA tip.

BACKGROUND

Robotic insertion of magnetically steered lateral-wall EAs has been shown to reduce insertion forces in vitro and in cadavers. No previous study of robot-assisted insertion has considered force on the basilar membrane.

METHODS

Insertions were executed in an open-channel scala-tympani phantom. A force plate, representing the basilar membrane, covered the channel to measure forces in the direction of the basilar membrane. An electromagnetic source generated a magnetic field to steer investigational EAs with permanent magnets at their tips, while a robot performed the insertion.

RESULTS

When magnetic steering was sufficient to pull the tip of the EA off of the lateral wall of the channel, it resulted in at least a 62% reduction of force on the phantom basilar membrane at insertion depths beyond 14.4 mm (p < 0.05), and these beneficial effects were maintained beyond approximately the same depth, even with 10 degrees of error in the estimation of the modiolar axis of the cochlea. When magnetic steering was not sufficient to pull the EA tip off of the lateral wall, a significant difference from the no-magnetic-steering case was not found.

CONCLUSIONS

This in vitro study suggests that magnetic steering of robotically inserted lateral-wall cochlear-implant EAs, given sufficient steering magnitude, can reduce forces on the basilar membrane in the first basilar turn compared with robotic insertion without magnetic steering.

Adaptation of the Standardized Hearing Outcomes Scattergram to Hearing Preservation in Cochlear Implantation

OBJECTIVE

Encourage adaptation of a standardized format for reporting hearing preservation outcomes in cochlear implantation (CI).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

One hundred seventy-eight postlingually deafened adults with bilateral SNHL and a preoperative low-frequency pure-tone average (LFPTA) 80 dB HL or better at 125, 250, and 500 Hz in the ear to be implanted.

INTERVENTIONS

Subjects underwent unilateral CI from 2013 to 2019 at a large referral center. Pre- versus postoperative LPFTA was used to generate a scattergram.

MAIN OUTCOMES MEASURES

Pre- versus postoperative activation LPFTA, percentage of patients fit with electric and acoustic stimulation, scattergram plot.

RESULTS

Average postoperative LFPTA was 68.6 dB HL (range 18-68) compared with 48.7 dB (range 5-80), preoperatively. At activation, the average LFPTA shift at CI activation was 20.5 dB HL (range 0-60) and 83.5% (n = 137) patients had hearing preserved, of whom 41.6% were fit with electric and acoustic stimulation throughout the study period. The scattergram successfully illustrates the distribution and number of patients with their respective audiometric outcomes.

CONCLUSIONS

The scattergram developed for reporting hearing outcomes in clinical trials is highly adaptable to reporting hearing preservation results in cochlear implant surgery. It represents a transparent and accessible option for reporting outcomes that can be used as a consistent format to allow for interstudy comparison and future meta-analysis.

Cost-Utility Analysis of Bilateral Cochlear Implantation in Adults With Severe to Profound Sensorineural Hearing Loss in Poland

OBJECTIVE

The aim of the study was to develop a Markov model and apply it for the evaluation of three different treatment scenarios for adult patients with severe to profound bilateral sensorineural hearing loss.

STUDY DESIGN

Prospective Observational Study.

SETTINGS

Hospital.

PATIENTS

A clinical group of 22 adult patients (59.1% men, 40.9% women) aged from 59.13 ± 8.9 years were included in the study. The study comprised two arms: patients in group 1 received the second cochlear implant one to three months after the first implant; while patients in group 2 got the second cochlear implant approximately one year after the first implant.

MAIN OUTCOME MEASURES

All participants were first asked to complete an AQoL-8D questionnaire. For the cost-effectiveness analyses, a Markov model analyzed as microsimulation was developed to compare the different treatment options.

RESULTS

The analyses show that bilateral cochlear implantation strategies are cost-effective compared to the 'no treatment' alternative when having a 10-year model time horizon. When all three model scenarios are compared, the bilateral simultaneous cochlear implantation strategy (Scenario 3) compared to the 'no treatment' option is even more cost-effective than the Scenarios 1 and 2, compared with the 'no treatment' alternative.

CONCLUSIONS

The model results summarize that bilateral (sequential and simultaneous) cochlear implantation that are represented in the model scenarios, are cost-effective strategies for Polish adult patients with bilateral severe to profound sensorineural hearing loss.

A New CT Parameter for Predicting Residual Hearing Preservation in Cochlear Implantation: The "Basal Turn-Facial Ridge Angle"

OBJECTIVES

We suggest a simple measurement, called the "basal turn-facial ridge (BT-FR) angle," for determining the electrode insertion axis using preoperative temporal bone computed tomography (CT) to predict hearing preservation (HP) in cochlear implantation (CI).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Eighty-two ears that underwent CI between 2010 and 2018 were included. Ears with preoperative thresholds less than or equal to 80 dB HL at 125, 250, and 500 Hz were enrolled and grouped using the criteria of Skarżyński et al.: Group 1, complete or partial HP; Group 2, minimal HP or complete hearing loss.

INTERVENTION

All subjects underwent CI with soft surgery techniques through the round window approach.

MAIN OUTCOME MEASURES

The BT-FR angle is the angle between the basal turn line (BT-line), which is a straight line passing through the center of the longitudinal axis of the BT, and the facial ridge line, which is a straight line running from the endpoint of the BT-line to a point just above the facial ridge.

RESULTS

The BT-FR angle was 2.5 ± 2.9 degrees in Group 1 and -0.3 ± 2.7 degrees in Group 2 (p = 0.003). The angle and hearing loss showed a significant negative correlation (r = -0.401, p = 0.002). In multiple linear regression, "age at operation" (β coefficient 0.260; p = 0.001) and the "BT-FR angle" (-1.967; p = 0.001) were significant variables affecting the degree of residual hearing loss.

CONCLUSIONS

The BT-FR angle, which can be measured simply, may be useful to predict residual HP after CI.

Benefits of Binaural Integration in Cochlear Implant Patients with Single-Sided Deafness and Residual Hearing in the Implanted Ear

The purpose of the study is to gauge the benefits of binaural integration effects (redundancy and squelch) due to preserved low-frequency residual hearing in the implanted ear of cochlear implant users with single-sided deafness. There were 11 cochlear implant users (age 18-61 years old) who had preserved low-frequency hearing in the implanted ear; they had a normal hearing or mild hearing loss in the contralateral ear. Patients were tested with monosyllabic words, under different spatial locations of speech and noise and with the cochlear implant activated and deactivated, in two listening configurations-one in which low frequencies in the implanted ear were masked and another in which they were unmasked. We also investigated how cochlear implant benefit due to binaural integration depended on unaided sound localization ability. Patients benefited from the binaural integration effects of redundancy and squelch only in the unmasked condition. Pearson correlations between binaural integration effects and unaided sound localization error showed significance only for squelch (r = -0.67; p = 0.02). Hearing preservation after cochlear implantation has considerable benefits because the preserved low-frequency hearing in the implanted ear contributes to binaural integration, presumably through the preserved temporal fine structure.

Genetic testing has the potential to impact hearing preservation following cochlear implantation

Background: Recent advances in less-invasive surgery and electrode design allow for a high degree of hearing preservation (HP) after cochlear implantation (CI), although residual hearing still deteriorates in some patients. To date, the factors predictive of preserving residual hearing remain a controversial topic.Objective: The aim of this study was to investigate the predictive factors, including the etiology of hearing loss (HL) as a patient-related factor, influencing residual HP after CI.Methods: Forty-four patients (50 ears, 41 families) with residual acoustic hearing who underwent CI were included. Auditory thresholds before and at 6 months after initial activation were measured. Genetic testing was performed to identify the responsible genes for HL.Results: We identified the cause of HL in 21 families (51.2%). HP was marginally correlated with age at implantation, while it was independent of pre-operative low-frequency hearing thresholds, cochlear duct length, and electrode length. We found that patients who had pathogenic variants in the CDH23, MYO7A, or MYO15A gene showed statistically better HP scores compared with patients with HL due to other causes (p = .002).Conclusions: Identification of the etiology of HL using genetic testing is likely to facilitate the prediction of HP after implant surgery.