Cochlear implantation in Waardenburg syndrome: Systematic review and meta-analysis

OBJECTIVE

Waardenburg syndrome (WS) is a genetic condition associated with moderate to profound sensorineural hearing loss. The aim of this review is to characterize cochlear implant (CI) outcomes in patients with a confirmed clinical diagnosis of WS.

DATA SOURCES

MEDLINE, Ovid EMBASE, and Cochrane Library.

REVIEW METHODS

All reports describing defined sets of patients with WS who underwent CI and subsequent evaluation of clinical outcomes were included. To harmonize outcome data between studies that used different measures, a binary variable Favored CI was developed to capture success of procedures (1 = favored, 0 = unfavored) based on original authors' description, commentary, discussion, and conclusions. Expert reviewers independently reviewed and selected articles, extracted data and scored Favored CI values. Synthetic and analytic meta-analyses were implemented using standard analytic techniques.

RESULTS

Twenty articles meeting inclusion criteria provided data on 192 WS patients and 210 CIs. The mean age at CI was 3.8 years (95% confidence interval [95%CI]; 3.1-4.5 years), and the mean duration of follow up was 5.2 years (95% CI; 3.4-7.0 years). Surgical complications were rare (11/210 implants, 5.2%) where gusher was the most common complication. CIs yielded favorable hearing outcomes in 90% (95% CI; 84-94%) of cases, and appear successful for those with temporal bone anomalies (p = 0.04).

CONCLUSIONS

Quantitative synthesis of the study data demonstrates that in the majority of patients with WS, CI yield favorable hearing outcomes and low rates of surgical complications. CI has shown to provide clinical benefits in patients with WS.

Bilateral intracochlear schwannomas: histopathological confirmation and outcomes following tumour removal and cochlear implantation with lateral wall electrodes

Intracochlear schwannomas (ICS) are very rare benign tumours of the inner ear. We present histopathological proof of the extremely rare bilateral occurrence of intracochlear schwannomas with negative blood genetic testing for neurofibromatosis type 2 (NF2). Bilateral schwannomas are typically associated with the condition NF2 and this case is presumed to have either mosaicism for NF2 or sporadic development of bilateral tumours. For progressive bilateral tumour growth and associated profound hearing loss, surgical intervention via partial cochleoectomy, tumour removal, preservation of the modiolus, and simultaneous cochlear implantation with lateral wall electrode carrier with basal double electrode contacts was performed. The right side was operated on first with a 14-month gap between each side. The hearing in aided speech recognition for consonant-nucleus-consonant (CNC) phonemes in quiet improved from 57% to 83% 12 months after bilateral cochlear implantation (CI). Bilateral intracochlear schwannomas in non-NF2 patients are extremely rare but should be considered in cases of progressive bilateral hearing loss. Successful tumour removal and cochlear implantation utilizing a lateral wall electrode is possible and can achieve good hearing outcomes.

Evaluation of musical emotion perception and language development in children with cochlear implants

OBJECTIVES

While the primary purpose of cochlear implant (CI) fitting is to improve individuals' receptive and expressive skills, musical emotion perception (MEP) is generally ignored. This study assesses the MEP and language skills (LS) of children using CI.

METHODS

26 CI users and 26 matched healthy controls between the ages of 6 and 9 were included in the study. The Test of Language Development (TOLD) was applied to evaluate the LS of the participants, and the Montreal Emotion Identification Test (MEI) was applied to evaluate the MEP.

RESULTS

MEI test scores and all subtests of TOLD were statistically significantly lower in the CI group. Also, there was a statistically significant and moderate correlation between the listening subtest of TOLD and the MEI test.

CONCLUSIONS

MEP and language skills are poor in children with CI. Although language skills are primarily targeted in CI performance, improving MEP should also be included in rehabilitation programs. The relationship between music and the TOLD's listening subtest may provide evidence that listening skills can be improved by paying attention to the MEP, which is frequently ignored in rehabilitation programs.

Spread of activation and interaction between channels with multi-channel optogenetic stimulation in the mouse cochlea

For individuals with severe to profound hearing loss resulting from irreversibly damaged hair cells, cochlear implants can be used to restore hearing by delivering electrical stimulation directly to the spiral ganglion neurons. However, current spread lowers the spatial resolution of neural activation. Since light can be easily confined, optogenetics is a technique that has the potential to improve the precision of neural activation, whereby visible light is used to stimulate neurons that are modified with light-sensitive opsins. This study compares the spread of neural activity across the inferior colliculus of the auditory midbrain during electrical and optical stimulation in the cochlea of acutely deafened mice with opsin-modified spiral ganglion neurons (H134R variant of the channelrhodopsin-2). Monopolar electrical stimulation was delivered via each of four 0.2 mm wide platinum electrode rings at 0.6 mm centre-to-centre spacing, whereas 453 nm wavelength light was delivered via each of five 0.22 × 0.27 mm micro-light emitting diodes (LEDs) at 0.52 mm centre-to-centre spacing. Channel interactions were also quantified by threshold changes during simultaneous stimulation by pairs of electrodes or micro-LEDs at different distances between the electrodes (0.6, 1.2 and 1.8 mm) or micro-LEDs (0.52, 1.04, 1.56 and 2.08 mm). The spread of activation resulting from single channel optical stimulation was approximately half that of monopolar electrical stimulation as measured at two levels of discrimination above threshold (p<0.001), whereas there was no significant difference between optical stimulation in opsin-modified deafened mice and pure tone acoustic stimulation in normal-hearing mice. During simultaneous micro-LED stimulation, there were minimal channel interactions for all micro-LED spacings tested. For neighbouring micro-LEDs/electrodes, the relative influence on threshold was 13-fold less for optical stimulation compared electrical stimulation (p<0.05). The outcomes of this study show that the higher spatial precision of optogenetic stimulation results in reduced channel interaction compared to electrical stimulation, which could increase the number of independent channels in a cochlear implant. Increased spatial resolution and the ability to activate more than one channel simultaneously could lead to better speech perception in cochlear implant recipients.

Audiovisual integration in children with cochlear implants revealed through EEG and fNIRS

Sensory deprivation can offset the balance of audio versus visual information in multimodal processing. Such a phenomenon could persist for children born deaf, even after they receive cochlear implants (CIs), and could potentially explain why one modality is given priority over the other. Here, we recorded cortical responses to a single speaker uttering two syllables, presented in audio-only (A), visual-only (V), and audio-visual (AV) modes. Electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) were successively recorded in seventy-five school-aged children. Twenty-five were children with normal hearing (NH) and fifty wore CIs, among whom 26 had relatively high language abilities (HL) comparable to those of NH children, while 24 others had low language abilities (LL). In EEG data, visual-evoked potentials were captured in occipital regions, in response to V and AV stimuli, and they were accentuated in the HL group compared to the LL group (the NH group being intermediate). Close to the vertex, auditory-evoked potentials were captured in response to A and AV stimuli and reflected a differential treatment of the two syllables but only in the NH group. None of the EEG metrics revealed any interaction between group and modality. In fNIRS data, each modality induced a corresponding activity in visual or auditory regions, but no group difference was observed in A, V, or AV stimulation. The present study did not reveal any sign of abnormal AV integration in children with CI. An efficient multimodal integrative network (at least for rudimentary speech materials) is clearly not a sufficient condition to exhibit good language and literacy.

Auditory Spatial Discrimination and Sound Localization in Single-Sided Deaf Participants Provided with a Cochlear Implant

INTRODUCTION

Spatial hearing is most accurate using both ears, but accuracy decreases in persons with asymmetrical hearing between ears. In participants with deafness in one ear but normal hearing in the other ear (single-sided deafness [SSD]), this difference can be compensated by a unilateral cochlear implant (CI). It has been shown that a CI can restore sound localization performance, but it is still unclear to what extent auditory spatial discrimination can be improved.

METHODS

The present study investigated auditory spatial discrimination using minimum audible angles (MAAs) in 18 CI-SSD participants. Results were compared to 120 age-matched normal-hearing (NH) listeners. Low-frequency (LF) and high-frequency (HF) noise bursts were presented from 4°, 30°, and 60° azimuth on the CI side and on the NH side. MAA thresholds were tested for correlation with localization performance in the same participants.

RESULTS

There were eight good performers and ten poor performers. There were more poor performers for LF signals than for HF signals. Performance on the CI side was comparable to performance on the NH side. Most difficulties occurred at 4° and at 30°. Eight of the good performers in the localization task were also good performers in the MAA task. Only the localization ability at 4° on the CI side was positively correlated with the MAA at that location.

CONCLUSION

Our data suggest that a CI can restore localization ability but not necessarily auditory spatial discrimination at the same time. The ability to discriminate between adjacent locations may be trainable during rehabilitation to enhance important auditory skills.

Personal experience with the remote check telehealth in cochlear implant users: from COVID-19 emergency to routine service

PURPOSE

To critically illustrate the personal experience with using the "Remote Check" application which remotely monitors the hearing rehabilitation level of cochlear implant users at home and further allows clinicians to schedule in-clinic sessions according to the patients' needs.

METHODS

12-month prospective study. Eighty adult cochlear implant users (females n = 37, males n = 43; age range 20-77 years) with ≥ 36 months of cochlear implant experience and ≥ 12 months of stable auditory and speech recognition level volunteered for this 12-month long prospective study. For each patient, at the beginning of the study during the in-clinic session to assess the stable aided hearing thresholds and the cochlear implant integrity and patient's usage, the "Remote Check" assessment baseline values were obtained. "Remote Check" outcomes were collected at different times in the subsequent at-home sessions, to identify the patients that had to reach the Center. Chi-square test has been used for statistical analysis of the comparison of the "Remote Check" outcomes and in-clinic session results.

RESULTS

"Remote Check" application outcomes demonstrated minimal or no differences between all sessions. The at-home Remote Check application reached the same clinical outcomes as the in-clinic sessions in 79 out 80 of participants (99%) with high statistical significance (p < 0.05).

CONCLUSIONS

"Remote Check" application supported hearing monitoring in cochlear implant users that were not able to attend the in-clinic review during COVID-19 pandemic time. This study demonstrates that the application can be a useful routine tool also for clinical follow-up of cochlear implant users with stable aided hearing.

Association of Cochlear Implant Management Skills of Parents and Outcomes in Their Cochlear Implanted Wards: An Indian Perspective

Parental involvement in the rehabilitation process is one of the critical factors for the success of cochlear implants in their wards. Skills to use a cochlear implant (CI) device appropriately and manipulate the different settings are essential to gain maximum benefits. There was a need to have a tool in Hindi to assess the skills of parents to manage the CI device. The study was conducted with the following aims: To translate and adapt Self-administered Cochlear Implant Management Skills (CIMSSelf) into the Hindi language. To find an association between the CI management skills of parents and outcomes in their implanted wards. To compare pre-post retraining scores on CIMS-self in Hindi (HN) and to find out factors affecting the scores. CIMS-self (English) was translated into Hindi using the forward and backward translation method. CIMS-self (HN) was administered to 22 parents of cochlear implanted children to evaluate their CI device management skills in the pretraining phase. The questionnaire was re-administered between 2 and 4 weeks to check the reliability. The outcome of CI in the children was assessed using the test tools viz. Categories of Auditory Perception, Integrated Scales of Development, Speech Intelligibility Rating, and Meaningful Auditory Integration Scale (MAIS). Subjects with less than 100% score received retraining on CI device management skills. CIMS-self (HN) was readministered two weeks after completing training, and results were compared between pre-post training sessions. There was no significant correlation between CIMS-self (HN) scores and demographic of the parents and their implanted wards, CI device factors, and clinical outcomes. A significant correlation was found between the CIMS-self (HN) and MAIS scores (p < .05). The Cronbach's alpha for test-retest reliability of the CIMS-self (HN) survey was 0.998. Participants showed a significant improvement in CIMS-self (HN) scores following the intervention, demonstrating that the CIMS-self (HN) is sensitive enough to detect changes in CI device management following retraining. A client who self-reports difficulty may benefit from consultation if it helps to improve their confidence in CI device management. The CIMS-self (HN) survey can be used to evaluate and re-evaluate CI device management skills at regular intervals and may save clinical time.

MRI surveillance after translabyrinthine vestibular schwannoma resection and cochlear implantation: is it feasible?

PURPOSE

Cochlear implantation in patients with vestibular schwannomas is of increasing importance and interest. Two remaining challenges are the assessment of conduction of the cochlear nerve and the possibility of postoperative surveillance with magnetic resonance imaging. The aim of the current study was to assess follow-up imaging and determine the visibility of the internal auditory canal after vestibular schwannoma resection and cochlear implantation as well as in patients with persistent vestibular schwannomas and cochlear implants in place. Visibility of the internal auditory canal, cerebellopontine angle, and labyrinth were evaluated and graded.

METHODS

For this retrospective study, 15 MR examinations of 13 patients after translabyrinthine vestibular schwannoma resection and ipsilateral cochlear implantation were included. All patients had been implanted with an MED-EL cochlear implant. Magnetic resonance imaging was carried out on a 1.5T device. All patients were prepped according to the manufacturer's recommendations.

RESULTS

All 15 examinations were carried out without any adverse event during imaging, such as pain, magnet dislocation, or malfunction. The internal auditory canal and the cerebellopontine angle were sufficiently visible in all cases to allow for vestibular schwannoma follow-up.

CONCLUSION

Magnetic resonance imaging surveillance of the internal auditory canal following vestibular schwannoma resection and cochlear implantation is feasible and safe with modern implants with a 1.5T magnetic resonance imaging device using metal artifact reduction sequences. Necessary follow-up imaging should not be a contraindication for cochlear implantation in patients with vestibular schwannomas.

Impact of processing-latency induced interaural delay and level discrepancy on sensitivity to interaural level differences in cochlear implant users

PURPOSE

This study investigated whether an interaural delay, e.g. caused by the processing latency of a hearing device, can affect sensitivity to interaural level differences (ILDs) in normal hearing subjects or cochlear implant (CI) users with contralateral normal hearing (SSD-CI).

METHODS

Sensitivity to ILD was measured in 10 SSD-CI subjects and in 24 normal hearing subjects. The stimulus was a noise burst presented via headphones and via a direct cable connection (CI). ILD sensitivity was measured for different interaural delays in the range induced by hearing devices. ILD sensitivity was correlated with results obtained in a sound localization task using seven loudspeakers in the frontal horizontal plane.

RESULTS

In the normal hearing subjects the sensitivity to interaural level differences deteriorated significantly with increasing interaural delays. In the CI group, no significant effect of interaural delays on ILD sensitivity was found. The NH subjects were significantly more sensitive to ILDs. The mean localization error in the CI group was 10.8° higher than in the normal hearing group. No correlation between sound localization ability and ILD sensitivity was found.

CONCLUSION

Interaural delays influence the perception of ILDs. For normal hearing subjects a significant decrement in sensitivity to ILD was measured. The effect could not be confirmed in the tested SSD-CI group, probably due to a small subject group with large variations. The temporal matching of the two sides may be beneficial for ILD processing and thus sound localization for CI patients. However, further studies are needed for verification.

Caloric function as a predictor of cochlear implant performance

OBJECTIVES

Changes in vestibular function have been demonstrated following cochlear implantation (CI). The functional impact of these changes on CI performance has not been well-studied. We sought to assess whether caloric changes postimplantation could predict CI performance.

METHODS

Retrospective review of a prospectively collected database at a tertiary care hospital. Patients who underwent CI over a 22-year period (1999-2021) and had videonystagmography (VNG) testing pre- and postimplantation were included. Caloric responses were compared pre- versus post-implantation, and assessed for their ability to predict CI performance as evaluated using AzBio +10 decibels signal-to-noise ratio (dB S/N) scores.

RESULTS

43 CI recipients were included. There was a significant difference in the average maximal slow-phase velocity in response to caloric irrigation in the implanted ear pre- versus post-operatively (21.2 vs. 18.5 deg/s; p = 0.02). Controlling for age and pre-implantation speech recognition performance, pre- and post-implantation caloric responses in the implanted ear significantly predicted CI performance at 0-6 months and >6 months post-implantation. Caloric changes following implantation were not significantly correlated with CI performance.

CONCLUSION

CI impacts vestibular function as evidenced by changes in caloric responses. Vestibular function pre- and possibly post-CI may be clinically useful metrics for predicting some proportion of CI performance variability.

Cochlear Implantation in Children with Auditory Neuropathy: Meta-Analysis

BACKGROUND

Auditory neuropathy (AN) is a nosological entity of unknown etiology, which is associated with fluctuations in rates of speech discrimination. Its diagnosis is based on presence of otoacoustic emissions and lack of, or abnormal, brainstem auditory evoked potential. With respect to treatment, we have variable results in the literature about development of speech perception and skills, in children with AN and cochlear implant (CI) rehabilitation.

OBJECTIVES

Comparatively assessing results recorded for the development of auditory and speech skills in children with auditory neuropathy spectrum disorder (ANSD), who were subjected to cochlear implantation, in comparison to results recorded for children with sensorineural hearing loss associated with other causes was the objective of this study.

METHOD

A systematic literature review with meta-analysis was performed, with studies published from 1975 to 2023.

RESULTS

Nineteen studies were included in the systematic review, and eight were selected for the meta-analysis, which showed there was no evidence allowing the conclusion that the two groups were different from each other about results in speech performance after 1 year of CI placement.

CONCLUSION

Therefore, this study shows that CI provides the comparable benefit to children with ANSD in comparison to children with neurosensory hearing loss associated with other causes in their speech development.

Sheep as a large animal model for hearing research: comparison to common laboratory animals and humans

Sensorineural hearing loss (SNHL), caused by pathology in the cochlea, is the most common type of hearing loss in humans. It is generally irreversible with very few effective pharmacological treatments available to prevent the degenerative changes or minimise the impact. Part of this has been attributed to difficulty of translating "proof-of-concept" for novel treatments established in small animal models to human therapies. There is an increasing interest in the use of sheep as a large animal model. In this article, we review the small and large animal models used in pre-clinical hearing research such as mice, rats, chinchilla, guinea pig, rabbit, cat, monkey, dog, pig, and sheep to humans, and compare the physiology, inner ear anatomy, and some of their use as model systems for SNHL, including cochlear implantation surgeries. Sheep have similar cochlear anatomy, auditory threshold, neonatal auditory system development, adult and infant body size, and number of birth as humans. Based on these comparisons, we suggest that sheep are well-suited as a potential translational animal model that bridges the gap between rodent model research to the clinical use in humans. This is especially in areas looking at changes across the life-course or in specific areas of experimental investigation such as cochlear implantation and other surgical procedures, biomedical device development and age-related sensorineural hearing loss research. Combined use of small animals for research that require higher throughput and genetic modification and large animals for medical translation could greatly accelerate the overall translation of basic research in the field of auditory neuroscience from bench to clinic.

Contribution of macrophages to neural survival and intracochlear tissue remodeling responses following cochlear implantation

BACKGROUND

Cochlear implants (CIs) restore hearing to deafened patients. The foreign body response (FBR) following cochlear implantation (post-CI) comprises an infiltration of macrophages, other immune and non-immune cells, and fibrosis into the scala tympani, a space that is normally devoid of cells. This FBR is associated with negative effects on CI outcomes including increased electrode impedances and loss of residual acoustic hearing. This study investigates the extent to which macrophage depletion by an orally administered CSF-1R specific kinase (c-FMS) inhibitor, PLX-5622, modulates the tissue response to CI and neural health.

MAIN TEXT

10- to 12-week-old CX3CR1 + /GFP Thy1 + /YFP mice on C57BL/6J/B6 background was fed chow containing 1200 mg/kg PLX5622 or control chow for the duration of the study. 7 days after starting the diet, 3-channel cochlear implants were implanted in the ear via the round window. Serial impedance and neural response telemetry (NRT) measurements were acquired throughout the study. Electric stimulation began 7 days post-CI until 28 days post-CI for 5 h/day, 5 days/week, with programming guided by NRT and behavioral responses. Cochleae harvested at 10, 28 or 56 days post-CI were cryosectioned and labeled with an antibody against α-smooth muscle actin (α-SMA) to identify myofibroblasts and quantify the fibrotic response. Using IMARIS image analysis software, the outlines of scala tympani, Rosenthal canal, modiolus, and lateral wall for each turn were traced manually to measure region volume. The density of nuclei, CX3CR1 + macrophages, Thy1 + spiral ganglion neuron (SGN) numbers, and the ratio of the α-SMA + volume/scala tympani volume were calculated. Cochlear implantation in control diet subjects caused infiltration of cells, including macrophages, into the cochlea. Fibrosis was evident in the scala tympani adjacent to the electrode array. Mice fed PLX5622 chow showed reduced macrophage infiltration throughout the implanted cochleae across all time points. However, scala tympani fibrosis was not reduced relative to control diet subjects. Further, mice treated with PLX5622 showed increased electrode impedances compared to controls. Finally, treatment with PLX5622 decreased SGN survival in implanted and contralateral cochleae.

CONCLUSION

The data suggest that macrophages play an important role in modulating the intracochlear tissue response following CI and neural survival.

How standardised are antibiotic regimens in otologic surgery?

BACKGROUND

Within otologic surgery, a paucity of well-controlled studies assessing the use of systemic antibiotic to reduce surgical site infections exists. Moreover, discrepancies in wound classification of procedures challenge consensus in antimicrobial prescribing patterns. We sought to compare surgeons from two different health systems to examine how surgeons' prescribing habits compared to practice guidelines for numerous otologic procedures.

METHODS

An online questionnaire was distributed to 33 Canadian and 32 Austrian surgeons who regularly perform otologic surgery. Current systemic antibiotic prescribing habits for cochlear implantation, cholesteatoma surgery, stapes surgery, and tympanoplasty ± ossiculoplasty were collected.

RESULTS

Eighteen of 33 (54.5%) Canadian surgeons provided responses, while 18 of 32 (56.3%) of Austrian surgeons answered. Clear consistency with clinical practice guidelines exists for pre-operative antibiotics use in cochlear implant surgery and infected cholesteatoma surgery. However, for stapes surgery and tympanoplasty ± ossiculoplasty, consensus is lacking for both pre- and post-operative antibiotic prescribing habits. Notable differences between the two countries include post-operative antibiotics for cochlear implant surgery (Austria: 36.4%, Canada: 71.4%) and uninfected cholesteatoma surgery (Austria: 33.3%, Canada: 77.8%). Across all procedures, both induction and post-operative antibiotic administration was not significantly associated with surgeon seniority when stratified by five-year increments.

CONCLUSION

The lack of consensus among each country's otologic surgeons underscores the uncertainty in wound classification and thus, adherence to clinical practice guidelines.

Validation of the Norwegian Version of the Speech, Spatial and Qualities of Hearing Scale (SSQ)

INTRODUCTION

The main objective of the study was to validate the Norwegian translation of the Speech, Spatial and Qualities of Hearing Scale (SSQ) and investigate the SSQ disability profiles in a cochlear implant (CI) user population.

METHODS

The study involved 152 adult CI users. The mean age at implantation was 55 (standard deviation [SD] = 16), and the mean CI experience was 5 years (SD = 4.8). The cohort was split into three groups depending on the hearing modality: bilateral CIs (BCIs), a unilateral CI (UCI), and bimodal (CI plus contralateral hearing aid; HCI). The SSQ disability profiles of each group were compared with those observed in similar studies using the English version and other translations of the SSQ. Standard values, internal consistency, sensitivity, and floor and ceiling effects were investigated, and the missing-response rates to specific questions were calculated. Relationships to speech perception were measured using monosyllabic word scores and the Norwegian Hearing in Noise Test scores.

RESULTS

In the BCI group, the average scores were around 5.0 for the speech and spatial sections and 7.0 for the qualities section (SD ∼2). The average scores of the UCI and HCI groups were about one point lower than those of the BCI group. The SSQ disability profiles were comparable to the profiles in similar studies. The slopes of the linear regression lines measuring the relationships between the SSQ speech and monosyllabic word scores were 0.8 per 10% increase in the monosyllabic word score for the BCI group (explaining 35% of the variation) and 0.4 for the UCI and HCI groups (explaining 22-23% of the variation).

CONCLUSION

The Norwegian version of the SSQ measures hearing disability similar to the original English version, and the internal consistency is good. Differences in the recipients' pre-implantation variables could explain some variations we observed in the SSQ responses, and such predictors should be investigated. Data aggregation will be possible using the SSQ as a routine clinical assessment in global CI populations. Moreover, pre-implantation variables should be systematically registered so that they can be used in mixed-effects models.

Can an individual with low frequency hearing in the candidate ear benefit from a cochlear implant even if they have normal hearing in the other ear?

PURPOSE

To determine hearing preservation and subjective benefit after cochlear implant (CI) surgery in patients with low frequency hearing in the ear to be implanted (i.e., they have partial deafness, PD) and close to normal hearing in the other.

METHODS

There were two study groups. The test group was made up of 12 adult patients (mean age 43.4 years; SD 13.6) with normal hearing or mild hearing loss in one ear, and with PD in the ear to be implanted. The reference group consisted of 12 adult patients (mean age 44.5 years; SD 14.1) who had PD in both ears and who underwent unilateral implantation in their worse ear. Hearing preservation was assessed 1 and 14 months after CI surgery using the Skarzynski Hearing Preservation Classification System. The APHAB questionnaire was used to evaluate the benefit from the CI.

RESULTS

The differences in HP% between the groups were not significant: mean hearing preservation (HP%) in the test group was 82% one month after CI surgery and 75% some 14 months after implantation; corresponding results in the reference group were 71% and 69%. However, on the APHAB background noise subscale, the benefit in the test group was significantly larger than in the reference group.

CONCLUSION

To a large extent it was possible to preserve low-frequency hearing in the implanted ear. This means that individuals with low frequency hearing in the implanted ear (partial deafness) and with normal hearing in the other generally received more benefits from cochlear implantation than did patients with partial deafness in both ears. We conclude that residual low frequency hearing in the ear to be implanted should not be considered a contraindication for a CI in a patient with single-sided deafness.

Effects of an evidence-based model for cochlear implant aftercare delivery on clinical efficiency and patient outcomes

OBJECTIVES

To assess an evidence-based model (EBM) approach to cochlear implant (CI) aftercare that includes a modified, reduced treatment schedule for newly-implanted adult CI recipients consisting of four appointments (initial activation, 1-, 3- and 6- months postactivation) in the first year post-surgery.

METHOD

This prospective multicenter proof-of-concept study was conducted across three clinics in the United States by five experienced CI clinicians. Seventeen newly-implanted adult patients with postlingual hearing loss enrolled in the study. Hearing outcomes were measured using objective speech testing and subjective self-report measures.

RESULTS

Most recipients (14/17; 82%) were able to follow the four-appointment EBM schedule. The reduced number of visits translated into an average time savings of 3 hours per patient. Significant improvements in speech perception were observed at both 3- and 6-months postactivation, as measured by CNC words in quiet and AzBio sentences at +10 dB SNR, consistent with published results achieved by traditional practices. Recipients were significantly satisfied with telephone, music, small group conversation, and television listening at 6 months postactivation. Recipient satisfaction with overall service was rated as "excellent" by 14/14 (100%) respondents.

CONCLUSION

The four-appointment EBM approach delivered efficient and effective audiological aftercare to CI recipients in the first year following CI implantation.

Importance of congenital cytomegalovirus in the neonatal hearing screening program

INTRODUCTION

In newborns, hearing loss secondary to congenital Cytomegalovirus (CMVc) infection, despite its low prevalence, can cause a serious problem in the personal development and social integration of patients. Therefore, it is important to include the determination of CMV DNA as a neonatal screening tool.

MATERIALS AND METHODS

We have carried out a 5-year retrospective study, by describing the CMVc in the Autonomous Community of the Basque Country in newborns who did not pass the hearing screening in the early hearing loss detection program. The times of detection, confirmation (incidence) and intervention (treatment) are described.

RESULTS

Of 18,782 subjects studied, 58 (three per thousand live births) presented hearing loss. Of these, CMVc is guaranteed in four patients (one woman and three men). The mean time to hearing screening was 6.5 days (SD: ±3.69) and to detect CMV by polymerase chain reaction (PCR) in urine and saliva was 4.2 days (SD: ± 3.94). Time to confirm hearing loss by BAEP and audiological intervention 2.2 (SD: ±0.957) and 5 months (SD: ±3.741), respectively. Four hearing aid adaptations and one cochlear implant were performed.

DISCUSSION AND CONCLUSION

Neonatal hearing screening has established itself as a good public health program. The determination of viral DNA allows an early, specific and interdisciplinary diagnosis and treatment, in which otorhinolaryngology plays a fundamental role. Our study highlights the importance of including CMV PCR as a universal screening tool.

Overcoming developing-world challenges in cochlear implantation: A Nigerian perspective

The emergence of cochlear implantation (CI) in the mid-20th century was a transformation to the field of restorative otology. The advance in this field has not been felt in lower-income countries where a huge burden of profound hearing loss lies. The authors sought to review the literature on the practice of cochlea implantation in Nigeria. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews, we conducted a scoping review of the literature on CI in Nigeria. All observational studies with information on cochlear implants and/or implantation in Nigeria were included with no limitations on outcomes. The authors extracted the following data; age, sample size, sex, aetiology, outcome, type of devices, complications, challenges and the location of the surgery. The results were pooled and reported as frequencies and percentages. Three studies were utilised in this review. The study included 25 patients. The age of the identified patients ranged from 1.2 months to 63 years. There were slightly more males than females (52% males). The most common aetiology of deafness in the participants was following a febrile illness (40%), followed by deafness post-meningitis (24%). The challenges identified included high cost, lack of full rehabilitative facilities and staff, scepticism, and lack of funding. CI remains the most effective for those that are profoundly deaf. Although successful CI programmes exist in Nigeria, the number of implant programmes and the affordability are not yet commensurate to the needs of the entire Nigerian population.

Simultaneous cochlear implantation during resection of a cerebellopontine angle meningioma: case report

Cerebellopontine angle (CPA) meningiomas commonly involve the internal auditory canal (IAC). We report a case of a 68-year-old lady with idiopathic profound bilateral deafness with a meningioma which was discovered on workup for cochlear implantation. We performed simultaneous excision of her CPA and IAC meningioma with insertion of a cochlear implant (CI). She regained functional hearing with marked improvement in quality of life. Intraoperative electrophysiological testing can be used to confirm preservation of the cochlear nerve enabling simultaneous implantation which is preferable for clinical and logistical reasons. This creates an option for hearing rehabilitation at the time of IAC/CPA tumour surgery in appropriate patients.

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.

Matching the pitch perception of the cochlear implanted ear with the contralateral ear in patients with single-sided deafness: a novel approach

PURPOSE

Single-sided deaf patients following cochlear implantation often compare the sound quality of their implanted ear with normal hearing. The interaural differences can result in dissatisfaction with speech comprehension and reduced time of usage of the speech processor; hence, prolonging auditory adaptation time. The proposed calibration method presented in this study demonstrates how the frequency distribution of the cochlear implant can be set to adequately approximate the pitch perception of the contralateral normal hearing ear towards improving speech intelligibility in a noisy environment.

METHODS

In 12 postlingual single-sided deaf patients, subjective interaural pitch-matching was carried out to determine new central frequencies for the reallocation of the frequency bands of their speech processor (CP910, CP950 or CP1000, Cochlear, Australia). The patients were asked to compare the pitch of the tones presented to their normal hearing ear to the pitch of individual channels of their cochlear implant (CI522 or CI622, Cochlear, Australia). A third-degree polynomial curve was fit to the acquired matching frequencies to create the new frequency allocation table. Audiological measurements (free-field aided thresholds, speech reception thresholds, and monosyllabic word recognition score) in noise, together with a Speech, Spatial and Qualities of Hearing Scale (SSQ12) questionnaire (short version of the original SSQ) results were evaluated prior to the pitch-matching procedure, and again, 2 weeks later.

RESULTS

The free-field aided thresholds of the patients showed no greater shift than ± 5 dB following the procedure; however, their monosyllabic word recognition score in noise improved significantly (mean - 9.58%, SD 4.98%, matched pairs t test comparison: p < 0.001). The results of the SSQ12 questionnaire also showed significant improvement in speech intelligibility, sound localization, and sound quality (mean 0.96 points, SD 0.45 points, matched pairs t test comparison: p < 0.001).

CONCLUSIONS

Matching the pitch perception of the implanted cochlea with the sensation of the normal hearing contralateral ear, resulted in significant changes in the quality of hearing in patients with single-sided deafness. It is plausible the procedure can usher positive results in bimodal patients or following sequential bilateral cochlear implantation.

Postoperative optimization of cochlear implantation for single sided deafness and asymmetric hearing loss: a systematic review

OBJECTIVE

Identify and evaluate the effectiveness of methods for improving postoperative cochlear implant (CI) hearing performance in subjects with single-sided deafness (SSD) and asymmetric hearing loss (AHL).

DATA SOURCES

Embase, PubMed, Scopus.

REVIEW METHODS

Systematic review and narrative synthesis. English language studies of adult CI recipients with SSD and AHL reporting a postoperative intervention and comparative audiometric data pertaining to speech in noise, speech in quiet and sound localization were included.

RESULTS

32 studies met criteria for full text review and 6 (n = 81) met final inclusion criteria. Interventions were categorized as: formal auditory training, programming techniques, or hardware optimization. Formal auditory training (n = 10) found no objective improvement in hearing outcomes. Experimental CI maps did not improve audiologic outcomes (n = 9). Programed CI signal delays to improve synchronization demonstrated improved sound localization (n = 12). Hardware optimization, including multidirectional (n = 29) and remote (n = 11) microphones, improved sound localization and speech in noise, respectively.

CONCLUSION

Few studies meeting inclusion criteria and small sample sizes highlight the need for further study. Formal auditory training did not appear to improve hearing outcomes. Programming techniques, such as CI signal delay, and hardware optimization, such as multidirectional and remote microphones, show promise to improve outcomes for SSD and AHL CI users.

Optimizing the efficiency of ECAP measurements due to interpolation

BACKGROUND

Thresholds of electrically evoked compound action potentials (TECAP) may serve as starting points for electrophysiologically based fitting of cochlear implants. Absent TECAP data at single electrodes reduces the number of data points available for fitting and can be substituted by interpolation of measured data points.

AIM

To compare complete TECAP profiles with interpolated TECAP profiles of 5/22 (∼22.7%) and 11/22 (50%) electrode contacts.

MATERIAL AND METHODS

Single-centre, retrospective, observational study of data from 624 ears implanted with a Slim Modiolar (CI ×32) or Contour Advance (CI ×12, CI24RE(CA)) electrode array (Cochlear Ltd). The deviation of the complete measured TECAP profile from the same profile with missing and therefore interpolated TECAP values was quantified.

RESULTS

Interpolated TECAP profiles significantly differ from complete measured profiles especially at the basal and apical electrodes. Reference data for Slim Modiolar and Contour Advance electrodes mean profiles are provided.

CONCLUSIONS AND SIGNIFICANCE

Reducing the number of measured TECAP electrodes has to be weighted against losses in the TECAP accuracy of interpolated values. A clinically acceptable compromise may be a reduction from 22 to 11 even non-equidistant data points. While reducing ECAP measurement time, it is accompanied by a minimal loss of accuracy of the TECAP threshold profile.