Music and psychoacoustic perception abilities in cochlear implant users with auditory neuropathy spectrum disorder

OBJECTIVE

Auditory neuropathy spectrum disorder (ANSD) is a condition wherein the pre-neural or cochlear outer hair cell activity is intact, but the neural activity in the auditory nerve is disrupted. Cochlear implant (CI) can be beneficial for subjects with ANSD; however, little is known about the music perception and psychoacoustic abilities of CI users with ANSD. Music perception in CI users is a multidimensional and complex ability requiring the contribution of both auditory and nonauditory abilities. Even though auditory abilities lay the foundation, the contribution of patient-related variables such as ANSD may affect the music perception. This study aimed to evaluate the psychoacoustic and music perception abilities of CI recipients with ANSD.

STUDY DESIGN

Twelve CI users with ANSD and twelve age- and gendermatched CI users with sensorineural hearing loss (SNHL) were evaluated. Music perception abilities were measured using the Turkish version of the Clinical Assessment of Music Perception (T-CAMP) test. Psychoacoustic abilities were measured using the spectral ripple discrimination (SRD) and temporal modulation transfer function (TMTF) tests. In addition, the age of diagnosis and implantation was recorded.

RESULTS

Pitch direction discrimination (PDD), timbre recognition, SRD, and TMTF performance of CI users with ANSD were concordant with those reported in previous studies, and differences between ANSD and SNHL groups were not statistically significant. However, the ANSD group performed poorly compared with SNHL group in melody recognition subtest of T-CAMP, and the difference was statistically significant.

CONCLUSION

CI can prove beneficial for patients with ANSD with respect to their music and psychoacoustic abilities, similar to patients with SNHL, except for melody recognition. Recognition of melodies requires both auditory and non-auditory abilities, and ANSD may have an extensive but subtle effect in the life of CI users.

The effect of hearing loss on the use of lexical categories by Hebrew-speaking mothers of deaf children with cochlear implants

BACKGROUND AND OBJECTIVES

The frequency of use of nouns versus verbs in child-directed speech (CDS) of mothers to their normal hearing (NH) children has been investigated in various languages. Recent studies have shown that CDS to deaf children is affected by hearing loss. Thus, the main aim of the present study was to examine the effect of hearing loss on the use of content words by NH Hebrew-speaking mothers to their deaf children using CIs. The second aim was to compare the use of content words by mothers speaking to CI children to that of NH children of the same chronological age and NH children with the same hearing experience.

METHOD

Three groups of mother-child dyads participated: Ten mothers of deaf children with bilateral CIs (CIs) (age range 20-48 months), ten mothers of NH children matched to the deaf children by their chronological age (NCA), and ten mothers of NH children matched to the deaf children by their hearing experience (NHE). Data were collected from mother-child dyads performing natural activities. Two hundred utterances were transcribed and analyzed both quantitatively (tokens) and qualitatively (types) according to the use of lexical categories (noun, verb, adjective, and adverb).

RESULTS

The frequency of verbs and nouns, both types and tokens, was significantly higher than the frequency of adverbs and adjectives in the CDS of mothers to their children both with CIs and NH. No significant differences were found between the use of verb and noun tokens by mothers of children with NH in both groups. However, in the speech of mothers to the CI group, the use of verb tokens was significantly higher than the use of noun tokens, and the verb to noun ratio of tokens was significantly higher than that of the NHE group, and demonstrated a trend with the NCA group.

CONCLUSION

The fact that mothers of CI children use more verb than noun tokens strengthens the claim that they adopt a more directive style and controlling behaviors while interacting with their CI children. Also, it seems that mothers speaking to CI children are more sensitive to the children's linguistic needs according to the hearing experience and linguistic stage rather than the chronological age. The clinical implications are discussed.

Assessment of temporal processing functions in early period cochlear implantation

PURPOSE

The purpose of this study is to compare the temporal processing performance of children with cochlear implant (CI) according to the age of implantation and to determine their relation with auditory perception scores.

METHODS

In this study, 30 cochlear implant users and ten normal hearing children at 9 and 10 years were included. Children with cochlear implants are divided into two groups according to the age of implantation: group I includes participants whose implantation age is between 13 and 35 months (20 children), group II includes participants whose implantation age is between 36 and 45 months (10 children). Individuals were evaluated with random gap detection test (RGDT), duration pattern test (DPT), frequency pattern test (FPT), the Mr. Potato Head task, word recognition, and sentence recognition test.

RESULTS

A significant difference was found between the control and CI groups in temporal processing performance. The temporal processing ability of CI groups was significantly worse than those of normal hearing. Although there was no significant difference among the groups with cochlear implant in terms of temporal processing performance, children who started to use CI at an earlier age showed a tendency of better performance on temporal processing tasks. There was a significant relationship between Daily Sentence Test and FPT, and the Mr. Potato Head task and FPT rev (the score calculated by accepting the reverse patterns correctly). There was a significant relationship between duration of implant use and temporal ordering performance CONCLUSION: In this study, children with CI cannot perform as well as normal-hearing peers on temporal processing tasks, even if they had started to use their CIs at an early age. It is important to evaluate temporal processing in implanted individuals and to guide auditory training considering the evaluation results.

Development of a rapidly made, easily personalized drug-eluting polymer film on the electrode array of a cochlear implant during surgery

OBJECTIVE

To develop a drug-eluting polymer film which can be easily personalized and rapidly made on the electrode array of a cochlear implant during surgery.

METHODS

A precursor solution was prepared with poly lactic-co-glycolic acid (PLGA) and trichloromethane. Using a dip-coating method, the silicone electrode array (HiFocus 1J, Advanced Bionics) was coated in polymer film produced from the precursor solution containing one of three drugs: dexamethasone sodium phosphate (DSP), cytosine arabinoside hydrochloride (Ara-C), or nicotinamide adenine dinucleotide (NAD), and the release of these drugs from the polymer film was studied. The drug-eluting film on the electrode array was analyzed by environmental scanning electron microscopy (ESEM). The water contact angle and the impedance of the electrode array were measured before and after coating. Drug release kinetics was evaluated in a quasi-stationary release model, using high performance liquid chromatography every 24 h for 15 days.

RESULTS

Five electrode arrays were tested with each of the three drugs in the polymer film coating. Before and after coating, ESEM studies revealed that the drug-loaded PLGA coating yielded a smooth covering with an average thickness of 1.02 ± 0.05 μm. The mass of the coated electrode increased by 1.00 ± 0.03 mg. The water contact angle decreased after coating (102 ± 0.6° vs 77 ± 1.6°, p < 0.01) but there was no significant change in the average impedance of the electrodes after coating (0.9 ± 0.22 kΩ vs 1.0 ± 0.18 kΩ, p > 0.05). An in vitro drug kinetics study revealed a faster release in the first 24 h (63.4 ± 0.6%) and a sustained release over the following 15 days (78.3 ± 1.7% in 2 days, 95.6 ± 1.0% in 7 days and 99.1 ± 0.4% in 14 days). The release rate was not affected by the drug, dose or the thickness of the coating.

CONCLUSION

The dip-coating method is feasible for rapid casting of a drug-eluting PLGA film on an electrode array during CI surgery. The coated electrode array maintained its original morphology and became more hydrophilic. The loaded drug is released in a sustained manner and is easily regulated, and so the method might represent a potential application for clinical use in cochlear implantation.

Dynamic current steering with phantom electrode in cochlear implants

Phantom electrode (PE) stimulation can extend the lower limit of pitch perception with cochlear implants (CIs) by using simultaneous out-of-phase stimulation of the most apical primary electrode and the adjacent basal compensating electrode. The total electrical field may push the excitation pattern beyond the most apical electrode to elicit a lower pitch, depending on the ratio of current between the compensating and primary electrodes (i.e., the compensation coefficient σ). This study tested the hypothesis that dynamic current steering of PE stimuli can be implemented by varying σ over time to encode spectral details in low frequencies. To determine the range of σ for current steering and the corresponding current levels, Experiment 1 tested CI users' loudness balance and pitch ranking of static PE stimuli with σ from 0 to 0.6 in steps of 0.2. It was found that the equal-loudness most comfortable level significantly increased with σ and can be modeled by a piecewise linear function of σ. Consistent with the previous findings, higher σ elicited either lower or similar pitches without salient pitch reversals than lower σ. Based on the results of Experiment 1, Experiment 2 created flat, rising, and falling pitch contours of 300-1000 ms using dynamic PE stimuli with time-varying σ from 0 to 0.6 and equal-loudness current levels. In a pitch contour identification (PCI) task, CI users scored 80% and above on average. Increasing the stimulus duration from 300 to 1000 ms slightly but did not significantly improve the PCI scores. Across subjects, the 1000-ms PCI scores in Experiment 2 were significantly correlated with the cumulative pitch-ranking sensitivity in Experiment 1. It is thus feasible to use dynamic current steering with PE to encode low-frequency pitch cues for CI users.

The effect of dopamine on the comprehension of spectrally-shifted noise-vocoded speech: a pilot study

Objectives: Cochlear implantation has proven beneficial in restoring hearing. However, success is variable, and there is a need for a simple post-implantation therapy that could significantly increase implantation success. Dopamine has a general role in learning and in assigning value to environmental stimuli. We tested the effect of dopamine in the comprehension of spectrally-shifted noise-vocoded (SSNV) speech, which simulates, in hearing individuals, the signal delivered by a cochlear implant (CI).Design and study sample: Thirty-five participants (age = 38.0 ± 10.1 SD) recruited from the general population were divided into three groups. We tested SSNV speech comprehension in two experimental sessions. In one session, a metabolic precursor of dopamine (L-DOPA) was administered to participants in two of the groups; a placebo was administered in the other session.Results: A single dose of L-DOPA interacted with training to improve perception of SSNV speech, but did not significantly accelerate learning.Conclusions: These findings are a first step in exploring the use of dopamine to enhance speech understanding in CI patients. Replications of these results using SSNV in individuals with normal hearing, and also in CI users, are needed to determine whether these effects can translate into benefits in everyday language comprehension.

Surgical complications of cochlear implantation: a 25-year retrospective analysis of cases in a tertiary academic center

PURPOSE

Despite the advances made in cochlear implantation techniques, the associated complication rates are still high. Here, we aimed to analyze cases, with extensive follow-up data, associated with a large sample of patients to identify complications related to cochlear implants and to present our surgical experience and the technique that we used in order to follow surgical rules/medical purpose to avoid any complications.

METHODS

We retrospectively examined cases involving 2597 patients (1342 males; 1255 females; age 1-88 years) who underwent cochlear implantation procedures between November 1995 and July 2019, and we classified complications as minor and major.

RESULTS

The mean age at the time of implantation was 6.48 (Min: 1/Max: 88) years. The cause of deafness was congenital in 76.5% of the patients and acquired in 16.8%. The overall rate of complications in the study was 3.7% (n = 97). The minor and major complication rates were 3.0 and 0.7, respectively. Further, while the most common minor complication we encountered was vertigo, the most common major complication was implant extrusion.

CONCLUSION

Fixing the cochlear implant receiver-stimulator with the bone-recess technique and sealing the posterior tympanotomy site with a piece of muscle in order to follow surgical rules/medical purpose to avoid any complications. Following the insertion of the electrode into the cochlea, the muscle closure of the cochleostomy site or the round window restores the original anatomy and in order to follow surgical rules/medical purpose to avoid any complications. We have developed this highly effective technique with years of experience and have not had a major surgical complication in 5 years.

Does bimodal hearing increase self-assessed abilities and hearing outcomes when compared to unilateral cochlear implantation?

Objective: The primary objective of this study was to compare the applicability and benefit of providing unilateral cochlear implant (CI) users with a contralateral hearing aid (HA).Design: This retrospective (case-control) study was conducted in a hospital-based CI centre. Participants self-assessed their hearing via two questionnaires (SSQ₁₂ and HISQUI₁₉). Objective postoperative speech perception was assessed via aided thresholds and speech perception tests (monosyllabic words, disyllabic words, and sentences) in quiet and noise.Study sample: A CI-only group (n = 113, mean age 55.1 ± 14.2 years) and a bimodal group (n = 50, mean age 56.7 ± 15.2) participated in the study.Results: No significant difference in SSQ₁₂ or HISQUI₁₉ scores was observed between groups. The bimodal group had a significantly better aided hearing level (p = 0.020) and speech discrimination score (p = 0.019).Conclusions: Bimodal (CI + HA) users have significantly better speech understanding than unilateral CI-only users, although this benefit may not be reflected in self-assessed outcomes. Counselling about bimodal hearing must cover expectations about potential benefits.

Application of Wireless Contralateral Routing of Signal (CROS) Technology in Unilateral Cochlear Implant Users

INTRODUCTION

Single cochlear implantation usually provides substantial speech intelligibility benefits but bilaterally deaf, unilaterally implanted subjects will continue to experience limitations due to the head shadow effect, like single-sided deaf individuals. In the treatment of individuals with single-sided deafness one option is contralateral routing of signal (CROS) devices, which constitute a non-surgical intervention of the second ear in unilaterally implanted individuals.

METHOD

Twelve experienced adult cochlear implant users with Naída Q70 processor and the CROS device used in combination participated in the study. For the study 3 conditions were provided: cochlear implant only, omnidirectional microphone mode (CROS deactivated); cochlear implant plus CROS activated, omnidirectional microphone mode and cochlear implant plus CROS activated, UltraZoom mode. Speech reception thresholds were determined in quiet and noise. Subjective feedback regarding the practical usability of the CROS device and the perceived benefit were collected.

RESULTS

There was a 27.6% improvement in speech understanding in quiet and 32.5% improvement in noise when CROS device was activated. Using advanced directional microphones, a statistically significant benefit of 35% was obtained. The responses to the questionnaires revealed that the subjects perceived benefit in their everyday lives when using the CROS device with their cochlear implants.

CONCLUSION

The investigated CROS device used by unilateral CI recipients in cases where bilateral implantation is not an option provides both subjective and objective speech recognition benefit when the signal is directed to the CROS device. Unfavourable conditions where speech is presented from the cochlear implant side and noise from the CROS side or diffusely were not included in this evaluation since the CROS device adds additional noise and performance is expected to decrease as has previously been shown.

Sculpting the temporal bone: an easy reversible cochlear implant electro-array stabilization technique

PURPOSE

Since the beginning of cochlear implant (CI) surgery, several techniques to fixate the electrode array at the cochleostomy and stabilize it have been described; however, most techniques use autologous tissues such as fascia, muscle, fat or fibrin glue. We describe a new surgical technique aimed to stabilize the electrode array of a CI without using autologous tissues or artificial materials.

MATERIALS AND METHODS

The surgical technique described consists in creating three stabilizing channels in the temporal bone for the electrode array. The first one in a partially opened aditus, the second one in a partially preserved Koerner's septum (KS) and the last one in the sinodural angle. The procedure was performed in five human temporal bones using a straight array; a radiography was made to confirm the correct placement of the electrode array and afterwards all temporal bones were shaken using a Titramax 1000 platform. The correct placement of the array post-shaking was then confirmed using the microscope and another radiography.

RESULTS

No migration of the electrodes outside the cochlea was observed. The CI cable remained in the same position at the aditus and the KS in all the temporal bones. In three cases (60%), the electrode array moved away from the groove carved in the sinodural angle.

CONCLUSIONS

The new surgical technique described stabilizes the electrode array using the temporal bone's normal anatomy, preserving the middle ear spaces, facilitating the ulterior explantation and reimplantation if necessary, and may reduce cost and surgery time.

Ultrasonic Wave Bone Cutting Technique (Piezotome) in Cochlear Implant Surgery by Veria Technique

To study use of ultrasonic wave bone cutting technique (piezotome) in cochlear implant surgery by veria technique. The Piezoelectric device is a bone cutting tool that transmits ultrasonic high frequency vibrations through a metallic tip to selectively cut bone while sparing the surrounding soft tissues. We have used the piezo tools instead of the perforator in over 50 cases of Cochlear Implant by the non mastoidectomy Veria technique [which uses a specially designed hand piece perforator with a guide (Kiratzidisa et al. in ORL J Otorhinolaryngol Relat Spec 64:413-416, 2002)]. These tools are helpful in: straightening the posterior bony canal wall, making the well for Implant bed, making space for excess electrodes and removing bone tissue close to dura without risk of injury to dura. Though use of Piezo tools in various otologic surgeries has been described but we feel the piezo tools will be an important tool in a CI surgeon's armament.

A novel frameshift mutation in SOX10 causes Waardenburg syndrome with peripheral demyelinating neuropathy, visual impairment and the absence of Hirschsprung disease

Waardenburg syndrome (WS) is a group of genetic disorders associated with varying components of sensorineural hearing loss and abnormal pigmentation of the hair, skin, and eyes. There exist four different WS subtypes, each defined by the absence or presence of additional features. One of the genes associated with WS is SOX10, a key transcription factor for the development of neural crest-derived lineages. Here we report a 12-year-old boy with a novel de novo SOX10 frameshift mutation and unique combination of clinical features including primary peripheral demyelinating neuropathy, hearing loss and visual impairment but absence of Hirschsprung disease and the typical pigmentary changes of hair or skin. This expands the spectrum of currently recognized phenotypes associated with WS and illustrates the phenotypic heterogeneity of SOX10-associated WS.

What can we learn from adult cochlear implant recipients with single-sided deafness who became elective non-users?

Objective: This retrospective study investigates the incidence of elective cochlear implant (CI) non-use amongst a cohort of adult CI recipients with single-sided deafness (SSD), identifies the causes that led to non-use, and assesses how non-use could be prevented. Methods: All adults with SSD who received a CI between 2008 and 2018 and who became elective CI non-users were included. Elective non-users were defined as CI recipients who decided to stop using their CI or, if explantation was necessary, refused reimplantation. Results: 5/114 (4.4%) adults with SSD who received a CI became elective non-users. The 5 non-users were a mean 44.2 years old (range 33-70 years) at implantation, had a mean duration of deafness of 7.1 years (range 0.5-20 years) at implantation, and used their CI for a mean 11.5 months (range 1.5-60 months) before (fully) discontinuing use. The primary cause of elective non-use was postoperative discouragement due to unrealistic expectations (4 participants) regarding sound perception with the CI or about the greater than expected level of commitment necessary for rehabilitation. Conclusions: Elective non-use among adult CI recipients with single-sided deafness was very rare and could be further prevented by comprehensive counselling to ensure that candidates have realistic expectations about the rehabilitation requirements and the outcomes with the CI.

Incomplete partition type III revisited-long-term results following cochlear implant

BACKGROUND

Incomplete partition type III (IP III) is defined by a missing lamina cribrosa between the cochlea and the internal auditory canal (IAC). Cochlear implantation (CI) may result in an insertion of the electrode array into the IAC. The aim of this study is to evaluate CI surgery protocols, long-term audiological outcome, mapping and electrophysiological data after CI in IP III patients.

MATERIALS AND METHODS

Nine IP III patients were implanted with perimodiolar electrode arrays between 1999 and 2014; eight of them were included in this study. We evaluated mapping data, stapedius reflexes, electrode impedances and ECAP thresholds. We matched them with 3 CI patients each with normal cochlear morphology regarding sex, age, side, implant type and surgical date. Speech discrimination was evaluated with the Oldenburger sentence test for adults, Göttingen audiometric speech test for children and the Freiburger monosyllabic word test.

RESULTS

3 years after CI IP III patients showed a significant increase in pulse width, calculated electric load and electrode impedances in basal electrodes. Intraoperative electrically-evoked stapedius reflexes could be measured in all patients. Speech recognition scores were lower than average scores for matched patients, but without statistical significance.

CONCLUSIONS

The significant increase of pulse width, electric load and electrode impedances of basal electrodes over time seem to be characteristic for IP III patients probably occurring due to fibrosis and neurodegeneration of the cochlear nerve. The long term audiological results are stable. Intraoperative imaging and stapedius reflexes are highly recommended to control the right position of the electrode array.

Mothers' emotional experiences related to their child's diagnosis of deafness and cochlear implant surgery: Parenting stress and child's language development

OBJECTIVES

The present study aims to assess the emotional experiences, specifically parenting stress, of mothers of children with cochlear implants (CIs), and their children's language development before surgery and at three and six months after CI activation.

METHODS

Twenty mothers of children with CIs were interviewed before their children's surgery about their experiences in connection with the diagnosis of deafness, the surgery and the activation of the CI. The Parenting Stress Index questionnaire and the MacArthur-Bates-Communication Development Inventory were administered before the surgery and at 3 and 6 months after the CI activation.

RESULTS

Analysis of the qualitative data resulting from the interviews showed that the mothers' emotional experiences before the CI surgery were complex. Mothers reported both positive and negative emotions related to deafness, diagnosis and surgery, benefits of the CI, coping strategies and future expectations. The mothers of children with more advanced lexical production six months after CI activation displayed a high frequency of themes related to positive emotions, thoughts and coping strategies before the surgery. Distress on the part of the mothers, perceptions of difficulties in their child and instances of parent-child dysfunctional interaction were negatively and significantly related to the child's language and communication development.

CONCLUSIONS

The findings support the importance of assessing the mother's emotional experience in relation to diagnosis and CI activation before the surgery. IMPLICATIONS FOR CLINICAL PRACTICE ARE DISCUSSED: specifically, the importance of the support offered to the parents, aimed at enhancing both their awareness of their expectations about their child's rehabilitation process and their self-efficacy in supporting the child's adaptation to the use of the CI.

Impact of cochlear abnormalities on hearing outcomes for children with cochlear implants

OBJECTIVE

Evaluate the impact of cochlear anomalies on hearing outcomes for pediatric patients with cochlear implants.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care center.

SUBJECTS AND METHODS

Charts were retrospectively reviewed for cases where pediatric cochlear implant surgery was performed between 2002 and 2018 at a single, tertiary care institution. Patients were divided into groups based on the presence or absence of radiological cochlear abnormalities, which were further classified as low or high risk anomalies. Hearing outcomes were evaluated by measuring pure tone averages and word recognition scores preoperatively, 3 and 12 months postoperatively, in addition to the most recent test results.

RESULTS

There were 154 ears implanted in our cohort of 100 patients. 107 ears had normal cochlear anatomy, 31 had low risk, and 16 had high risk abnormalities. The most common modality of preoperative imaging was CT scan. Postoperative mean pure tone average (PTA) was significantly higher in patients with inner ear anomalies compared to those with normal anatomy. No significant difference in PTA was noted between low versus high risk patients. <50% of patients had word recognition scores available within the first year following surgery.

CONCLUSION

Abnormalities of the inner ear significantly influenced hearing outcomes over time following cochlear implant surgery when compared to pediatric patients with normal anatomy. Obtaining hearing testing can be difficult in very young children and therefore future studies are warranted to further investigate the impact that cochlear abnormalities may have on hearing outcomes following cochlear implant surgery.

Cochlear implant outcomes in children with attention-deficit/hyperactivity disorder: Comparison with controls

OBJECTIVES

The coincidence of attention-deficit/hyperactivity disorder (ADHD) and hearing loss in the children has adverse effects in speech, cognition, communication and motor development. This can influence cochlear implant (CI) outcomes negatively. The aim of this study was to compare auditory, language, speech, cognition, communication and motor outcomes between CI children with versus without ADHD.

METHODS

Nineteen CI children with ADHD and twenty-three age and gender matched children without ADHD at the Shiraz CI center ranging in age from 37 to 60 months were participated in this cross-sectional study. The developmental quotient in auditory, receptive and expressive language, speech and cognition skills was evaluated through Newsha Developmental Scale. The Persian version of the Ages and Stages Questionnaire (ASQ) was used to assess children's developmental status in fine and gross movements, communication, problem solving, and personal-social domains. A comparison of the results between two groups was made by the Mann-Whitney test.

RESULTS

CI children with ADHD had significantly lower Newsha developmental quotients in cases of auditory, receptive and expressive language, speech and cognition skills compared to the control group (P = 0.027 to <0.001). A significant difference was observed between children with and without ADHD in fine and gross movements, communication, problem solving, and personal-social domains of ASQ at 60 months (P = 0.029 to 0.003).

CONCLUSION

Children with ADHD showed decreased ability in auditory, language, speech, cognition, motor and communication skills following CI compared to children without ADHD. It can guide clinician to provide these children with more specific rehabilitation program to improve their skills.

Binaural cue sensitivity in cochlear implant recipients with acoustic hearing preservation

Bilateral acoustic hearing in cochlear implant (CI) recipients with hearing preservation may allow access to binaural cues. Sensitivity to acoustic binaural cues has been shown in some listeners combining electric and acoustic stimulation (EAS), yet remains poorly understood and may be subject to limitations imposed by the electrical stimulation and/or amplification asymmetries. The purpose of this study was to investigate the effect of stimulus level, frequency-dependent gain, and the addition of unilateral electrical stimulation on sensitivity to low-frequency binaural cues. Thresholds were measured for interaural time and level differences (ITD and ILD) carried by a low-frequency, bandpass noise (100-800 Hz). 16 adult CI EAS listeners (mean age = 50.2 years) each participated in three listening conditions: acoustic hearing only at 90 dB SPL, acoustic hearing only at 60 dB SPL with frequency-dependent gain, and acoustic hearing plus unilateral CI at 60 dB SPL with frequency-dependent gain applied to the acoustic channels only. Results revealed thresholds within the ecologically relevant ITD and/or ILD range for most EAS listeners. No significant effects of presentation level, frequency-dependent gain, or the addition of unilateral electrical stimulation on the resultant thresholds for ITDs or ILDs were observed at the group level. Correlational analyses related ITD and ILD thresholds to the degree of EAS benefit (i.e., advantage of acoustic hearing in the implanted ear) for speech recognition in diffuse noise. There was a significant relationship between EAS benefit and ITD thresholds, but no statistically significant relationship between EAS benefit and ILD thresholds. In summary, the results of this study are not consistent with our previous data obtained with simulated EAS in normal-hearing listeners, which showed significant binaural interference by a unilateral electrical "distractor" (Van Ginkel et al., 2019). The difference between studies suggests that chronic exposure to unilateral electrical stimulation combined with bilateral acoustic stimulation may reduce interference effects, perhaps because listeners adapt to the presence of the constant but binaurally incongruous CI stimulus. These results are consistent with past studies that demonstrated no interference in spatial hearing tasks due to the addition of a unilateral CI in adult EAS listeners.

The relation of hearing-specific patient-reported outcome measures with speech perception measures and acceptable noise levels in cochlear implant users

Objective: To investigate the relation of a hearing-specific patient-reported outcome measure (PROM) with speech perception and noise tolerance measurements. It was hypothesised that speech intelligibility in noise and noise tolerance may explain a larger part of the variance in PROM scores than speech intelligibility in quiet.Design: This cross-sectional study used the Speech, Spatial, Qualities (SSQ) questionnaire as a PROM. Speech recognition in quiet, the Speech Reception Threshold in noise and noise tolerance as measured with the acceptable noise level (ANL) were measured with sentences.Study sample: A group of 48 unilateral post-lingual deafened cochlear implant (CI) users.Results: SSQ scores were moderately correlated with speech scores in quiet and noise, and also with ANLs. Speech scores in quiet and noise were strongly correlated. The combination of speech scores and ANL explained 10-30% of the variances in SSQ scores, with ANLs adding only 0-9%.Conclusions: The variance in the SSQ as hearing-specific PROM in CI users was not better explained by speech intelligibility in noise than by speech intelligibility in quiet, because of the remarkably strong correlation between both measures. ANLs made only a small contribution to explain the variance of the SSQ. ANLs seem to measure other aspects than the SSQ.

Potential insertion complications with cochlear implant electrodes

Objectives: The aim of this discussion paper and literature review was to estimate the incidence of a variety of complications associated with the surgical placement of cochlear implant (CI) electrode arrays and to discuss the implications and management of sub-optimal electrode placement. Results: A review of the peer-reviewed literature suggests that the incidence of incomplete electrode insertion and kinking is more prevalent in straight arrays and not more than about 2% in CI recipients with normal cochlear anatomy/patency. Incidence of tip fold-over is greater with perimodiolar arrays but also occurs with straight arrays and is typically less than 5%. Conversely, electrode migration is more common with straight arrays, and high rates (up to 46%) have been reported in some studies. Scalar translocations have also been reported for both perimodiolar and straight arrays. Higher rates have been reported for stylet-based perimodiolar electrodes inserted via cochleostomy (up to 56%), but with much lower rates (<10%) with both sheath-based perimodiolar arrays and lateral wall arrays. Electrode positioning complications represent a significant proportion of perioperative CI complications and compromise the level of benefit from the device. Careful surgical planning and appropriate pre- and intraoperative imaging can reduce the likelihood and impact of electrode positioning complications. There is also evidence that newer array designs are less prone to certain complications, particularly scalar translocation. Conclusions: It is important that implanting surgeons are aware of the impact of sub-optimal electrode placement and the steps that can be taken to avoid, identify and manage such complications.

Cochlear implantation in Ménière's disease: a systematic review of literature and pooled analysis

Objective: The aim of this study was to evaluate the effect of cochlear implantation (CI) in advanced Ménière's disease (MD).Design: The initial search on PubMed, EMBASE, and Cochrane databases yielded 171 articles; no language restriction was applied.Study sample: A total of 11 articles met the inclusion criteria and were included in this systematic review. Six articles provided patient-level data on improvement in speech recognition testing after CI.Results: The methodological quality of included studies was assessed by examining the study design, level of evidence, method of measurement and adequacy of outcome reporting. A random-effect model was fitted for calculating weighted means. Post-operative improvement in word recognition score (WCS) was 50.8% (95% confidence interval: 34.6-67.1%); general improvement of vestibular symptoms after CI was found in 67% of the pooled patients; when reported in the studies, quality of life (QoL) and tinnitus were also generally improved after CI.Conclusions: CI in advanced MD is a valid option providing good outcomes in terms of speech performances, regardless of the disease duration, uni- or bilaterality, age at implantation, previous therapeutic procedures and stage of activity of MD.

The emerging role of hearing loss rehabilitation in patients with vestibular schwannoma treated with Gamma Knife radiosurgery: literature review

Stereotactic radiosurgery (SRS) is currently the most common treatment for small- to medium-size vestibular schwannoma (VS). Despite favorable outcome, hearing deterioration still remains an underestimated problem, and the role of hearing rehabilitation is an underinvestigated topic. Among available technologies, cochlear implant (CI) should represent a valid alternative in sporadic VS with single-sided deafness and in neurofibromatosis (NF2) with bilateral profound hearing loss. A literature review of the current clinical data was performed searching scientific literature databases. From all of the articles found, 16 papers were selected. Forty-four subjects treated with radiosurgery (18 male, 19 female, and in 7 cases, sex were not specified; 43 NF2 and 1 sporadic VS) were included in the analysis. Epidemiological, clinical, tumor, treatment, and audiological data were collected. Clinical outcome at last follow-up showed an audiological improvement in 25 of the 44 patients. The audiological outcome was unchanged in 16 cases. Audiological deterioration was recorded in 3 cases. Severity of NF2 phenotype, long history of ipsilateral profound deafness before implantation, progressive tumor growth, and high radiation dose (20 and 40 Gy) were found in patients with a worst audiological outcome. Hearing rehabilitation can improve audiological results for VS patients following SRS in selected cases. Hearing rehabilitation with cochlear implant (CI) in SSD leads to partial restoration of binaural hearing with an improvement in speech comprehension in noise and in sound localization, and partial suppression of subjective incapacitating tinnitus. SRS followed by CI may represent in selected cases a potential emerging option in the management of these patients, aimed at improving their quality of life. Possible implications for the follow-up of these patients are still present, although partially resolved.

Evolution of Cochlear implant mapping and vestibular function in a pediatric case of Labyrinthitis

Background

Vestibular symptoms such as vertigo and imbalance are known to occur in some cochlear implant patients during the immediate postoperative period; however, acute vertigo in implanted children occurring remotely from the postoperative period has not been previously well-described.

Case presentation

A three-year-old girl with a history of bilateral sequential cochlear implantation presented with acute labyrinthitis associated with sudden onset of vertigo, balance impairment, and decline in right cochlear implant function 2 years after her most recent implant surgery. We describe her audiological and vestibular testing results during both the acute phase and following medical management and recovery.

Conclusion

Acute labyrinthitis should be considered when sudden onset vertigo and/or imbalance presents in children with cochlear implants outside of the perioperative period. Such symptoms should prompt early assessment of cochlear implant function, so that the device can be reprogrammed accordingly.

Long-term functional outcomes of hearing and speech rehabilitation efficacy among paediatric cochlear implant recipients in Shandong, China

Purpose: To evaluate the auditory performance and speech intelligibility of 100 children with bilateral profound sensorineural hearing loss up to 3 years after cochlear implantation.Methods: A cohort study was established consisting of 100 children who received cochlear implantation at Shandong Ear Nose and Throat Hospital from 2012 to 2015. Children were examined after 1 month, 1, 2, and 3 years of implantation to assess auditory performance and speech intelligibility using standard tools. The paired Wilcoxon signed-rank test was used to assess whether the scores obtained at different testing points differed significantly. The Mann-Whitney test was utilized to examine the between-group differences (e.g., age at implantation).Results: Three years after implantation, 60% out of 100 children reached the maximal category (7) of categorical auditory performance and 37% achieved the highest category (5) of speech intelligibility rating. Significant improvements were found over time in categorical auditory performance category and speech intelligibility rating (from month 1 to year 1, p < 0.001; from year 1 to year 2, p < 0.001; and from year 2 to year 3, p < 0.001). Larger improvements in auditory outcomes and speech intelligibility were observed in children with a younger age at implantation and those who received speech therapy.Conclusions: Cochlear implantation appears to make a significant, positive contribution to the development of communication skills of young congenital and prelingually deaf children in China. These improvements continue for up to 3 years after implantation. Positive outcomes appear to be associated with earlier age at implantation and receipt of speech therapy.Implications for rehabilitationBilateral sensorineural hearing loss.Bilateral sensorineural hearing loss in children can cause delay in speech development, poor language skills and potentially disorders in psychological behaviour and social isolation.Cochlear implantation (CI) is an effective strategy that helps children with bilateral sensorineural hearing loss gain the ability to hear and continue to develop language.This study shows that the auditory performance and speech intelligibility of deaf children who speak Mandarin continued to improve up to 3 years of implantation, when follow-up ceased.

Endoscopic approach to the round window through posterior tympanotomy for cochlear implantation in children: A study on feasibility

OBJECTIVE

To demonstrate the feasibility of rigid endoscopy through posterior tympanotomy, which provides both a view of the round window and direction of the scala tympani in children.

METHODS

After a standard mini-invasive surgical approach with postauricular access and transmastoid posterior tympanotomy of 2 mm, a 0°, 1.9 mm diameter and 11 cm long endoscope is positioned in proximity of the upper part of the posterior tympanotomy to obtain a panoramic view of the inferior part of the medial wall of the tympanic cavity. Surgical complications and changes in hearing threshold were analyzed.

RESULTS

Eight children were submitted to cochlear implantation with endoscopic assistance through posterior tympanotomy. Complete visualization of the round window niche was possible in every ear. No complications related to the procedure were observed. Preoperative threshold was preserved in 9 of 10 ears.

CONCLUSIONS

Direct endoscopic view through the posterior tympanotomy allows visualization of the entire round window niche as well as the angle of introduction of the multi-electrode array along the direction of the scala tympani.