Hearing loss and cochlear implantation in Chudley McCullough syndrome: A case series

Lessons from LOCHI.

Pediatric Cochlear Implantation: Who is a Candidate in 2020?

THE ARGUMENT FOR FITTING BIMODALLY If you see a child tomorrow with a hearing loss in both ears, will you recommend one hearing aid or two? The obvious answer is two. You would have a hard time finding a dispensing professional today who does not agree that the benefits of bilateral hearing aid fitting make it the standard of care for those with binaural hearing loss. While the benefits of binaural hearing and the advantage of bilateral fitting are beyond the scope of this article (e.g., see Litovsky et al.,1 Kochkin2), these facts are undisputed in hearing healthcare circles. The industry's confidence in bilateral hearing aids is supported by current trends in fitting. In 1980 only 27% of hearing aid fittings were bilateral.3 Today, it is an amazing 86% for those with binaural hearing loss.4 So, what is bimodal fitting and why should dispensing professionals care? Bimodal fitting means different stimuli are presented to each ear. For the purposes of this paper, it means a cochlear implant in one ear and a hearing aid in the other. But, you may ask, don't cochlear implant audiologists take care of that? The answer is no, at least not usually. Personal experience (first author), communication with cochlear implant audiologists, and the literature5 suggest that most hearing aids in bimodal devices are fitted outside the cochlear implant center. Thus, if you have a patient who receives a cochlear implant in one ear, you will most likely be the one responsible for the continuing care of the hearing aid in the contralateral ear. It is in the best interests of both your patient and you to know how to optimize the hearing aid fitting for the best bimodal performance. If you fit hearing aids on children, the question is not if you will be responsible for managing a child with bimodal devices, but rather when. The number of unilateral cochlear implant recipients who continue to use contralateral hearing aids is clearly increasing (Figure 1). The conventional wisdom that cochlear implants and hearing aids should not be used simultaneously is archaic,6,7as we will show in this paper.Figure 1: Percentage of unilateral cochlear implant users choosing to wear a hearing aid in the contralateral ear. Sources: Tyler et al.,8 Cowan and Chin-Lenn9.BIMODAL DEVICE USE IN CI WEARERS Significant advances over the years in cochlear implant technology, speech-coding strategies, and surgical techniques have resulted in substantial improvements in the auditory-only speech-understanding abilities of cochlear implant recipients.10 As a result, the candidacy criteria approved for cochlear implantation in the United States has progressively expanded. When Cochlear Corporation, Ltd., introduced the original Nucleus® cochlear implant in 1985, the only candidates approved by the Food and Drug Administration were adults with profound bilateral sensorineural hearing loss of post-linguistic origin who had 0% open-set speech recognition using hearing aids. Now, under the FDA criteria approved in 2005, candidates can be adults or children aged 12 months and older, and can have either pre- or post-lingual onset of hearing loss. Although mid- and high-frequency hearing must still be profound (hearing thresholds >90 dB HL), low-frequency hearing loss can be moderate for adults (hearing thresholds >40 dB HL) and severe for children over age 2 (hearing thresholds >70 dB HL). Further, best-aided pre-operative speech-recognition criteria have been raised from 0% to <60%. Figure 2 shows the current criteria for each age group.Figure 2: Current FDA-approved audiometric and speech-recognition criteria for cochlear implantation with the Nucleus device, by age group. (For children, the open-set word-recognition test recommended is the Lexical Neighborhood Test [LNT] or Multisyllabic Lexical Neighborhood Test [MLNT], which are available from www.auditec.com.)For persons with bilaterally profound sensorineural deafness (the purple-shaded area in Figure 2), cochlear implants are clearly the intervention of choice because many obtain little or no benefit from hearing aids. However, for children aged 2 years and up and for adults, there is a range of low-frequency thresholds (the green and yellow areas, respectively) that fall within the approved audiometric range for cochlear implants. Hearing aids often fail to provide adequate performance for these patients,11but a unilateral cochlear implant alone does not provide all the known benefits that arise from listening with two ears rather than one. Binaural benefits from perception of interaural differences in time and intensity are well known to improve speech-recognition performance, particularly in background noise, due to a combination of head shadow, binaural redundancy, and binaural squelch effects (e.g., see Byrne, 198112 for a review). Further, bilateral inputs provide the potential for good localization ability. Finally, a strong argument can be made for bilateral stimulation, especially in children, in light of the impact of auditory deprivation on perception. When a hearing-impaired ear remains unaided, speech-recognition ability in that ear significantly deteriorates over time,13,14 and there appears to be a limited window of opportunity for auditory system stimulation if the patient is to achieve maximal binaural functioning.15 Bilateral implantation is not for everyone. For example, there might be significant usable hearing in one ear. There may be insurance reimbursement or financial barriers. Parents may worry about surgery or preserving one ear for possible future technology or treatments. These concerns may or may not be well-founded. Insurance reimbursement is not the obstacle it once was. Cochlear brand implants are designed to be “backward compatible” so future advances can be applied to implants done today. Cotanche reported that treatment, e.g., hair cell regeneration, may be 20 years or more away.16 However, unilateral versus bilateral implantation in children is ultimately the parents' choice and their wishes must be respected. The less expensive, non-invasive fitting of a hearing aid on the ear contralateral to a cochlear implant allows preservation of hearing in that ear and may provide the benefits of binaural stimulation. SUMMARY OF THE LITERATURE The bimodal fitting approach was first reported in the literature in the early 1990s (e.g., Shallop et al., 199217). Concerns were initially expressed that patients might be unable to combine the two very different sound sources for central processing. Fortunately, this has not proven to be the case. In fact, some researchers have argued that bimodal stimulation may provide “complementary” cues for processing of signals that may be advantageous to speech perception.18 Specifically, the lower frequencies provided by the hearing aid can provide information about the fundamental frequencies of a talker's voice and vowel information, while the mid- and high-frequency information from the cochlear implant can provide information needed on manner and place of articulation of consonants. It has also been suggested that localization ability, sound quality, and music perception may be enhanced by bimodal devices compared with bilateral cochlear implants.19,20 Studies have reported significant speech-recognition improvements for bimodal listening compared to either the patients' pre-operative bilateral hearing aid use or their post-operative use of the hearing aid or cochlear implant alone. This has been shown in adults17,21–23 and in children.24–26 For example, in a study by Luntz et al.,26 12 subjects (3 post-lingually impaired adults and 9 pre-lingually impaired adults and children aged 7 and older) were tested on sentences in noise after 7 to 12 months of using bimodal devices. Both speech (at 55 dB HL) and noise (at 45 dB HL) were presented from a frontal loudspeaker. Average speech-recognition scores were only 12.9% for the hearing aid alone and 60.7% for the cochlear implant alone, but bimodal listening produced an average score of 75.6% correct. Localization abilities have been shown to improve with bimodal devices relative to use of either device alone for some, although not all, adult2728 and pediatric1,24 patients. Many users of bimodal devices have also reported higher levels of satisfaction and perceived benefit than with hearing aids worn pre-implantation, although cosmetic and handling concerns of using the two devices have sometimes been expressed,29 emphasizing the need for sufficient counseling and training. It is also important to consider that children may need more time to learn to use bimodal cues.25 There is debate over the relative effectiveness of bilateral cochlear implants versus bimodal devices. Overall, however, the published literature on bimodal devices has been quite positive (e.g. see Ching et al. for a review18). A judicious approach would be to fit a hearing aid contralaterally to the implant on patients who show sufficient benefit from the hearing aid and are able to use the binaural cues provided. FACTORS IN FITTING THE HEARING AID Certain aspects of the fitting need to be considered and possibly modified for optimal use of bimodal devices. Dispensing professionals who follow proven, evidence-based protocols for hearing aid fitting, however, will require minimal adaptation of their normal procedure. The American Academy of Audiology has published a Pediatric Amplification Protocol and all professionals dispensing hearing aids to children should be familiar with it.30 Optimization of the hearing aid in bimodal fittings essentially requires three steps. First, the cochlear implant map must be stable. You will need to communicate with the cochlear implant audiologist to know when this has been accomplished. Second, a frequency response should be selected for the hearing aid that will provide the best speech intelligibility. This is established by starting with a hearing aid that has been fitted and verified using a prescriptive formula. While the first author has had success using NAL-NL1,31 and Ching recommended it as an optimal starting point,32 those who are proficient with DSL[i/o]33 or another validated prescriptive approach should not be discouraged from using it as the starting point. From the initial prescription, two alternate frequency responses should be programmed into the hearing aid and adjusted for equal loudness. This is easy in multiple-memory digital hearing aids. As the limits of the hearing aid permit, program one should be the selected prescriptive formula frequency response. Program two should have 6-dB per octave less amplification in the low frequencies (-6 dB at 1000 Hz, -12 dB at 500 Hz, and -18 dB at 250 Hz). Program three should have 6-dB per octave more amplification in the low frequencies (+6 dB at 1000 Hz, +12 dB at 500 Hz, and +18 dB at 250 Hz). Once the programs are established, the child should listen to connected discourse while the audiologist switches between programs to determine which one provides the clearest speech. This can be done by playing a recorded story or watching a child-friendly video. The cochlear implant should be turned off during this frequency response selection process. Ching reported that this procedure is appropriate for children as young as 6 years.32 For younger children, the professional may choose to default to the prescriptive response. Finally, the third step in the fitting protocol is to match overall loudness between the hearing aid and cochlear implant. Both the implant and the aid are turned on and the child is asked to report if the hearing aid is louder or softer than the cochlear implant. The aid is then adjusted accordingly. This can also be done while the child listens to a recorded story or watches a video. A chart like that in Figure 3 can be helpful for this task. Some children might experience loudness discomfort from amplification. If so, Ullauri et al. suggest starting with a lower volume setting on the hearing aid and raising it over time as acclimatization occurs until the level of balanced loudness is achieved.34Figure 3: Loudness balancing scale. Source: Cochlear in-house material.A flow chart for fitting the hearing aid in bimodal devices is shown in Figure 4. This recommended protocol has been validated in children and found to provide good binaural benefits.24 For the reader wishing more in-depth training, a tutorial is available at www.cochlearcollege.com. Ching et al. have also published excellent articles on fitting and adjusting the hearing aid for children wearing bimodal devices.2,35Figure 4: Optimizing the hearing aid in bimodal fitting. Source: Cochlear in-house material.CONCLUSIONS The use of bimodal devices is the recommended treatment option for children who meet cochlear implant candidacy but who either have some usable hearing in one ear or for other reasons get only one implant. Bimodal devices can be a successful alternative to bilateral hearing aids or to one cochlear implant alone. It is important to remember these three vital rules: (1) Work with the implant center to make sure the implant map is stable. (2) Fit the hearing aid frequency response for maximal speech intelligibility. (3) Balance the loudness with the cochlear implant and hearing aid. Bimodal fitting can provide optimal use of the different, but potentially complementary, bilateral cues provided by the acoustic amplifier and the electric stimulation from the implant.

Inter-trial coherence as a marker of cortical phase synchrony in children with sensorineural hearing loss and auditory neuropathy spectrum disorder fitted with hearing aids and cochlear implants

On the basis of strong research, universal newborn screening should be performed before age 1 month with repeat or follow-up testing for those who do not pass performed before age 3 months and intervention started before age 6 months. On the basis of strong research and consensus statement, tympanostomy tubes should be considered for individuals with bilateral persistent middle ear effusion for 3 months or greater and a documented conductive hearing loss. On the basis of consensus statement, all children with suspected hearing loss should have an age appropriate hearing test. On the basis of strong research, the most common form of congenital hearing loss is genetic. Most of this is nonsyndromic hearing loss.

Objective: The results of cochlear implantation in patients that present with auditory neuropathy spectrum disorder (ANSD) patients have been variably reported. The effectiveness of the treatment modality varies in such patients. Hearing rehabilitation in this group of patients has been very challenging. Considerable controversy exists whether to provide conventional amplification (hearing aids or personal FM systems) or cochlear implants (CI) to children with ANSD. With this background, we present our experience with select subset of ANSD cases that derived benefit from cochlear implant. Methodology: We studied and evaluated all the paediatric cases (i.e. less than 12 years of age) using audiological test battery. The cases with other co-morbidities, abnormality of auditory nerve and cochlea were excluded. Diagnosed cases of ANSD were given bilateral, behind the ear, digital hearing aids as per their behavioural responses for 6 months and enrolled for communication development in the auditory verbal habilitation program. They were evaluated for auditory perception using Category of Auditory Performance scoring system. The ANSD cases that derived “intermediate benefit” as per our criteria at 6 months post hearing aids were taken up for unilateral cochlear implant. All the implanted ANSD cases continued in auditory verbal habilitation program of our hospital and their progress on auditory perception post cochlear implant was monitored using CAP scoring system. Results: A total of 1313 cases were evaluated for hearing loss. Out of these 65 cases were detected to have ANSD (42 bilateral and 23 unilateral ANSD).Unilateral ANSD cases were excluded from the study. Hearing aids were fitted in all the bilateral ANSD cases. After 6 months of hearing aid fitting thirteen ANSD cases showed “intermediate benefit” and were taken up for cochlear implant. After 6 months of implant usage all ANSD cases showed “good” progress on CAP. Conclusion: Hearing aid trial should be given to all the cases diagnosed with ANSD and those who derive “intermediate benefit” from hearing aids and AVT should be considered for cochlear implant.

Best practices concerning the audiological management of the child diagnosed with auditory neuropathy spectrum disorder (ANSD) have not been definitively defined nor fully understood. One reason is that previous studies have demonstrated conflicting findings regarding the outcomes of cochlear implantation for children with ANSD. Thus, the question remains whether children with ANSD are able to achieve similar outcomes following cochlear implantation as those children with sensorineural hearing loss (SNHL). To assess speech perception outcomes for children with cochlear implants who have a diagnosis of ANSD as well as their age-matched peers who have sensorineural hearing loss. Retrospective study Thirty-five subject pairs (n = 70) ranging in age at implant activation from to 10 to 121 mo (mean 39.2 mo) were included in this retrospective study. Subjects were matched on variables including age at initial implant activation and months of implant use at postoperative test point. Speech recognition scores for monosyllabic and multisyllabic stimuli were compared across the subject groups. For those not developmentally and/or linguistically ready for completion of open-set speech recognition testing with recorded stimuli, GASP (Glendonald Auditory Screening Procedure) word recognition and/or questionnaire data using either the LittlEARS or Meaningful Auditory Integration Scale were compared across the groups. Statistical analysis using a repeated-measures analysis of variance (ANOVA) evaluated the effects of etiology (ANSD or SNHL) on postoperative outcomes. The results of this study demonstrate that children with ANSD can clearly benefit from cochlear implantation and that their long-term outcomes are similar to matched peers with SNHL on measures of speech recognition. There were no significant differences across the ANSD and SNHL groups on any of the tested measures. Cochlear implantation is a viable treatment option for children with a diagnosis of ANSD who are not making auditory progress with hearing aids that have been fit using the Desired Sensation Level method (DSL v5.0). Expected outcomes of cochlear implantation for children with ANSD, excluding children with cochlear nerve deficiency, are no different than for children with non-ANSD SNHL. These results are important for counseling families on the expected outcomes and realistic expectations following cochlear implantation for children with ANSD who demonstrate no evidence of cochlear nerve deficiency.

This study asks whether the LittlEARs Auditory Questionnaire (LEAQ), a caregiver measure, can differentiate between the early auditory development of children with bilateral cochlear implants (CIs), bilateral hearing aids (HAs), and children with Auditory Neuropathy Spectrum Disorder (ANSD) who wear CIs or HAs. The LEAQ is sensitive to impaired auditory development but has not previously been used to distinguish developmental changes between groups of children using different hearing technologies or with different types of hearing loss. We collected retrospective longitudinal LEAQ results from 43 children with HAs, 43 with CIs, and 18 with ANSD. The children with ANSD wore hearing technology. They were a similar age to the children without ANSD (23 months; SD = 15), while the CI group (14 months; SD = 8) was younger than the HA group (24 months; SD = 18) [F(2,98.48) = 3.4; p = 0.04]. The CI group often participated in their first LEAQ pretreatment. Participants completed between one and seven LEAQs. Scores ranged between zero and 35 (mean = 18.36). We conducted a linear mixed-effects analysis, which included age or time since device fitting, hearing type (HA, CI, or ANSD), and presence of a comorbidity as fixed effects. A secondary analysis assessed effects of device audibility, measured by the Speech Intelligibility Index or Articulation Index, and consistency of device use obtained from device datalogs. Children with CIs progressed faster than their peers with HAs or ANSD [χ2(8) = 24.51; p = 0.002]. However, within a subsample that included consistency of device use (β7 = -0.20 ± 0.38, t = -0.52; β8 = 0.93 ± 0.82, t = 1.13) and audibility (β6 = -0.70 ± 1.45, t = -1.87; β7 = 0.87 ± 0.89, t = 0.98), study group did not significantly influence rate of improvement on the LEAQ. In addition, children with developmental delays in all three study groups demonstrated significantly slower LEAQ score improvement [χ2(6) = 23.60; p < 0.001] and a trend toward decreased consistency of device use [F(1) = 3.31; p = 0.07]. As we expected, children in the CI and HA groups were more likely to achieve auditory skills indicated in early rather than later LEAQ questions. There was less variability in the responses of the ANSD group [CI: interquartile range (IQR) = 9; HA: IQR = 8; ANSD: IQR = 1]. There was no connection between LEAQ growth and speech perception outcomes in a subsample [r(6) = 0.42; p = 0.30]. The LEAQ is a useful tool for monitoring initial auditory development in very young children and can inform early treatment decisions.

GPSM2 Mutations Cause the Brain Malformations and Hearing Loss in Chudley-McCullough Syndrome

Current evidence supports the benefits of cochlear implants (CIs) in children with hearing loss, including those with auditory neuropathy spectrum disorder (ANSD). However, there is limited evidence regarding factors that hold predictive value for intervention outcomes. This retrospective case-control study consisted of 66 children with CIs, including 22 with ANSD and 44 with sensorineural hearing loss (SNHL) matched on sex, age, age at CI activation, and the length of follow-up with CIs (1:2 ratio). The case and control groups were compared in the results of five open-set speech perception tests, and a Forward Linear Regression Model was used to identify factors that can predict the post-CI outcomes. There was no significant difference in average scores between the two groups across five outcome measures, ranging from 88.40% to 95.65%. The correlation matrix revealed that younger ages at hearing aid fitting and CI activation positively influenced improvements in speech perception test scores. Furthermore, among the variables incorporated in the regression model, the duration of follow-up with CIs, age at CI activation, and the utilization of two CIs demonstrated prognostic significance for improved post-CI speech perception outcomes. Children with ANSD can achieve similar open-set speech perception outcomes as children with SNHL. A longer CI follow-up, a lower age at CI activation, and the use of two CIs are predictive for optimal CI outcome.

The limitation of risk factors as a means of prognostication in auditory neuropathy spectrum disorder of perinatal onset

Purpose: To record language and auditory skills development before and after cochlear implantation (CI) in children with Auditory neuropathy spectrum disorder (ANSD), and to determine the outcome after cochlear implant in patients with ANSD in comparison to patients with sensorineural hearing loss (SNHL). Materials and methods: Cases Included in this study were divided into two groups. Group I: includes, 13 children diagnosed with ANSD, of them 7 cases were subjected to CI. Group II: includes, 20 cases of SNHL, of them 10 patients were subjected to cochlear implant. For all cases language therapy was given regularly for 6 months pre-operatively and 6 months post-operatively. Auditory Skills Checklist (ASC) and The Arabic language test (receptive, expressive and total language Quotients) were used to monitor the progress concerning auditory skills and language development. Results: There was significant improvement in SNHL group and ANSD group after cochlear implantation regarding auditory skills (AS) and language development and almost the same outcome was obtained in both groups. Conclusion: Cases with ANSD improved markedly after cochlear implantation and No differences were noticed in outcome between SNHL & ANSD groups.

Background: Cochlear implantation (CI) has emerged as a promising intervention for children with auditory neuropathy spectrum disorder (ANSD). Several studies have investigated the efficacy of CIs in children with ANSD, demonstrating improvements in auditory performance and language skills following implantation. Whether the benefits and outcomes of CIs in children with ANSD are comparable to children with sensorineural hearing loss (SNHL) is still debatable. The present updated systematic review and meta-analysis evaluated the outcomes of CI for children with ANSD compared to children with SNHL. Methods: A meta-analysis was conducted on studies that included pediatric patients and the outcomes of CI in patients with ANSD versus SNHL were compared. A comprehensive search was performed using the following electronic databases: PubMed, Scopus, Web of Science, EBSCOhost, and Cochrane Central Register of Controlled Trials (CENTRAL). Results: Fourteen studies (number of patients = 722 patients) were included. The total number of patients in the ANSD and SNHL groups in the present systematic review was 212 and 520, respectively. The most utilized assessment tests were the Speech Intelligibility Rating (SIR) and Categories of Auditory Performance (CAP) scores. The pooled estimate showed that patients with ANSD had comparable CAP scores compared to patients with SNHL (MD: −0.52, 95% CI [−1.34, 0.29], p = 0.21). Likewise, three studies reported the SIR after CI and showed comparable findings between ANSD and SNHL patients. The pooled estimate showed that patients with ANSD had comparable SIR scores compared to patients with SNHL (MD: −0.26, 95% CI [−0.65, 0.13], p = 0.19). Conclusion: While the results show mixed findings across various outcome measures, the overall impact of CI on speech recognition and language development appears to be positive and comparable between ANSD and SNHL.

Objective The objective of this study was to determine the prevalence, risk factors, and audiological characteristics of auditory neuropathy spectrum disorder (ANSD) in the pediatric population. Design A retrospective review of medical charts was conducted for children visiting two hospitals in Saudi Arabia. Study Sample Medical records of 1025 patients with sensorineural hearing loss (SNHL) were reviewed. We analyzed the databases for results of audiological examinations, risk factors, and outcomes of intervention including hearing aid (HA) and cochlear implantation (CI). Results Out of 1025 children with SNHL, 101 patients (9.85%) were identified to have ANSD. Audiological characteristics of the ANSD group revealed a severe-to-profound degree of hearing loss, all showed type A tympanogram and absent reflexes, absent auditory brainstem response (ABR) findings with present cochlear microphonic while otoacoustic emissions were absent in 54.5% of patients. The most prevalent risk factors for ANSD in this group were family history of hearing loss, consanguinity, hyperbilirubinemia, and low birth weight. Pure tone and speech detection thresholds improved significantly with CI compared to HA use in this sample of patients with ANSD. Conclusion This study shows that ANSD is not extremely rare among Saudi children with severe to profound hearing loss, with a prevalence of 9.85%.

Does parental experience of the diagnosis and intervention process differ for children with auditory neuropathy?