No Difference in Behavioral and Self-Reported Outcomes for Simultaneous and Sequential Bilateral Cochlear Implantation: Evidence From a Multicenter Randomized Controlled Trial

Objective: The primary aim of this study was to longitudinally compare the behavioral and self-reported outcomes of simultaneous bilateral cochlear implantation (simBiCI) and sequential BiCI (seqBiCI) in adults with severe-to-profound postlingual sensorineural hearing loss.Design: This study is a multicenter randomized controlled trial with a 4-year follow-up period after the first moment of implantation. Participants were allocated by randomization to receive bilateral cochlear implants (CIs) either, simultaneously (simBiCI group) or sequentially with an inter-implant interval of 2 years (UCI/seqBiCI group). All sequential patients where encouraged to use their hearing aid on the non-implanted ear over of the first 2 years. Patients were followed-up on an annual basis. The primary outcome was speech perception in noise coming from a source directly in front of the patient. Other behavioral outcome measures were speech intelligibility-in-noise from spatially separated sources, localization and speech perception in quiet. Self-reported outcome measures encompassed questionnaires on quality of life, quality of hearing and tinnitus. All outcome measures were analyzed longitudinally using a linear or logistic regression analysis with an autoregressive residual covariance matrix (generalized estimating equations type).Results: Nineteen participants were randomly allocated to the simBiCI group and 19 participants to the UCI/seqBiCI group. Three participants in the UCI/seqBiCI group did not proceed with their second implantation and were therefore unavailable for follow-up. Both study groups performed equally well on speech perception in noise from a source directly in front of the patient longitudinally. During all 4 years of follow-up the UCI/seqBiCI group performed significantly worse compared to the simBiCI group on spatial speech perception in noise in the best performance situation (8.70 dB [3.96 – 13.44], p < 0.001) and localization abilities (largest difference 60 degrees configuration: -44.45% [-52.15 – -36.74], p < 0.0001). Furthermore, during all years of follow-up, the UCI/seqBiCI group performed significantly worse on quality of hearing and quality of life questionnaires. The years of unilateral CI use were the reason for the inferior results in the UCI/SeqBiCI group. One year after receiving CI2, the UCI/seqBiCI group performance did not statistically differ from the performance of the simBiCI group on all these outcomes. Furthermore, no longitudinal differences were seen in tinnitus burden prevalence between groups. Finally, the complications that occurred during this trial were infection, dysfunction of CI, facial nerve palsy, tinnitus and vertigo.Conclusion: This randomized controlled trial on bilaterally severely hearing impaired participants found a significantly worse longitudinal performance of UCI/seqBiCI compared to simBiCI on multiple behavioral and self-reported outcomes regarding speech perception in noise and localization abilities. This difference is associated with the inferior performance of the UCI/seqBiCI participants during the years of unilateral CI use. After receiving the second CI however, the performance of the UCI/seqBiCI group did not significantly differ from the simBiCI group.Trial Registration: Dutch Trial Register NTR1722

The Effect of Earplugs in Preventing Hearing Loss From Recreational Noise Exposure : A Systematic Review

Importance: The prevalence of hearing loss among children and adolescents is rising dramatically, caused mainly by increased exposure to recreational noise. Objective: To present a systematic overview of the effectiveness of wearing earplugs to music venues, such as nightclubs and concert halls, to prevent hearing loss and tinnitus directly after exposure. Evidence Acquisition: PubMed, EMBASE, and the Cochrane Library databases were searched for articles from database inception to June 22, 2015, using the keywords music and earplugs and all synonyms. Titles, abstracts, and full text of retrieved articles were screened for eligible articles. The directness of evidence (relevance of the assessed articles) and risk of bias of eligible articles were assessed. For the included articles, the study characteristics and data on our outcomes of interest (hearing loss and tinnitus) were extracted. Data analysis occurred from June 22 to July 3, 2015. Findings: Of 228 articles screened, 4 were eligible for critical appraisal. After critical appraisal, 2 studies with a high directness of evidence and low or moderate risk of bias remained for data extraction. Only 1 of these articles was a randomized clinical trial, which found significantly lower postconcert differences in thresholds and a lower proportion of threshold shifts in the group using earplugs compared with the unprotected group. In the other study, only 3 individuals wore earplugs, and no significant differences were found between the 2 groups. Conclusions and Relevance: The available evidence on the effectiveness of earplugs in preventing hearing damage directly after recreational music exposure is scarce. Only 1 well-conducted randomized clinical trial was found, which showed that wearing earplugs to concerts is effective in reducing postconcert threshold shifts. There is a need for further research on this topic to strengthen the level of evidence. Physicians should promote awareness on the risks of recreational noise and recommend the use of earplugs among their patients who visit music venues

Effectiveness of Earplugs in Preventing Recreational Noise-Induced Hearing Loss : A Randomized Clinical Trial

IMPORTANCE: The incidence of hearing loss has risen in past years. Attendance at music festivals and concerts may contribute to this increasing problem. OBJECTIVE: To assess the effectiveness of earplugs in preventing temporary hearing loss immediately following music exposure. DESIGN, SETTING, AND PARTICIPANTS: A randomized, single-blind clinical trial was conducted on September 5, 2015, at an outdoor music festival in Amsterdam, the Netherlands. Normal-hearing adult volunteers were recruited via social media. An exclusion criterion was the participants' intention to wear earplugs. Of the 86 volunteers assessed, 51 were included in the study. All analyses were performed on an intention-to-treat basis. INTERVENTIONS: Participants were randomly assigned to a group using earplugs or an unprotected group during a 4½-hour festival visit. MAIN OUTCOMES AND MEASURES: The primary study outcome was a temporary threshold shift (TTS) on the audiogram, primarily for frequencies at 3 and 4 kHz. Secondary study outcomes included distortion product otoacoustic emission (DPOAE) measurements and claims of tinnitus using a questionnaire and tinnitus matching experiments. RESULTS: Of 51 participants included, 25 were randomized to the earplug group and 26 to the unprotected group. Nine in each group (36% and 35%, respectively) were men, and the mean (SD) ages were 27.3 (5.6) years in the earplug group and 27.0 (6.2) years in the unprotected group. Baseline demographics were similar in both groups. The time-averaged, equivalent A-weighted sound pressure level experienced was 100 dBA during the festival. A TTS over frequencies at 3 and 4 kHz after exposure was seen in 4 of 50 ears (8%) in the earplug group compared with 22 of 52 ears (42%) in the unprotected group (P < .001). The relative risk for a TTS after exposure was 5.3 (95% CI, 2.0-14.3) for the unprotected group vs the earplug group. The number needed to treat with earplugs for preventing 1 TTS was 2.9. The DPOAE amplitudes decreased significantly more over the frequencies 2 to 8 kHz in the unprotected group: the mean (SD) decrease in magnitude was 0.6 (2.8) dB in the earplug group vs 2.2 (1.9) dB in the unprotected group (P = .04). Newly induced tinnitus following sound exposure occurred in 3 of the 25 participants (12%) in the earplug group vs 10 of 25 (40%) in the unprotected group (difference, 28%; 95% CI, 3.6%-49.0%; P = .02). CONCLUSIONS AND RELEVANCE: Earplug use is effective in preventing temporary hearing loss after loud music exposure. The present randomized clinical trial adds proof to the scarce evidence and knowledge on this topic, which is a growing global problem. TRIAL REGISTRATION: trialregister.nl Identifier: NTR5401

No Squelch Effect After Sequential Bilateral Cochlear Implantation in Postlingually Deafened Adults : Is There a First Ear Advantage?

OBJECTIVES: To investigate whether a squelch effect develops in postlingually deafened adults after sequential bilateral cochlear implantation. STUDY DESIGN: Prospective study as part of a randomized controlled trial on the difference between simultaneous versus sequential bilateral cochlear implantation. SETTING: Tertiary referral center. PARTICIPANTS: Sixteen postlingually deafened adults. INTERVENTION: Sequential bilateral cochlear implantation with a 2-year interimplant interval. MAIN OUTCOME MEASURE: A squelch effect was defined as a better bilateral score than unilateral score on a speech-intelligibility-in-noise test with spatially separated sources. The squelch effect was evaluated for the participants' best performing cochlear implant (CI) ear, the left CI in the condition with speech from -60 degrees azimuth and noise from +60 degrees azimuth (S-60 N+60), the right CI (N-60 S+60), CI1 and CI2. Evaluations took place 1, 2 and median 4 years after sequential implantation. RESULTS: No significant squelch effect was found, except for the right CI (N-60 S+60) after 2 years. No differences in speech perception-in-noise from straight ahead were seen between CI1 and CI2. Comparing performance of participants whose better or worse ear was implanted first did not reveal differences either. For the best performing situation, 7/16, 6/16, and 3/12 participants exhibited a squelch effect after 1, 2, and 4 years of follow-up. CONCLUSIONS: Participants who underwent sequential bilateral cochlear implantation with a 2-year interimplant interval did not develop an evident squelch effect on group level after a median follow-up of 4 years. Individual participants were able to make use of the squelch effect. The less evident squelch effect is at odds with our group of simultaneously implanted bilateral cochlear implant users. Neither a difference between CI1 and CI2, nor implanting the better or worse ear first could explain the less evident squelch effect in these patients. TRIAL REGISTRATION: Dutch Trial Register NTR1722

Factors that influence outcomes in cochlear implantation in adults, based on patient related characteristics - a retrospective study

OBJECTIVE: Outcomes in speech perception following cochlear implantation in adults vary widely. Many studies have been carried out to identify and quantify factors that influence outcomes. This paper adds a new dimension to pre-existing literature. DESIGN: Single center retrospective cohort study. SETTING: University Medical Center Utrecht, The Netherlands. PARTICIPANTS: 428 adults with bilateral severe-to-profound sensorineural hearing loss, unilaterally implanted between February 1988 and March 2014. MAIN OUTCOME MEASURES: Univariable and multivariable linear regression analyses was carried out to identify factors that may influence outcomes from cochlear implantation. Consonant-vowel-consonant' word scores (CNCs) were recorded pre- and post-implant and were used as outcome measures in two groups of patients (pre- and postlingually deafened adults). As an added dimension, multiple imputation was implemented and evaluated to tackle 4% (17/407) missing data. RESULTS: For postlinguals, pre-implant speech perception score and age at onset of deafness are positive predictors and meningitis and otosclerosis as cause of deafness are negative predictors of post-implant speech perception. This model accounted for 26% of variance. For prelinguals, pre-implant speech perception score is the only strong positive predictor (Beta 0.524; p<0.001). This model accounted for 31% of variance. Age at implantation was not a significant predictor in either group. CONCLUSIONS: Speech perception is predicted by pre-implant speech perception, age at onset of deafness and etiology (meningitis and otosclerosis) for postlinguals and solely pre-implant speech perception for prelinguals. Age at implantation is of lesser importance in predicting speech perception outcome post-implant. Multiple imputation is a useful statistical techniques when analysing incomplete data sets. This article is protected by copyright. All rights reserved

Factors that influence outcomes in cochlear implantation in adults, based on patient related characteristics - a retrospective study

OBJECTIVE: Outcomes in speech perception following cochlear implantation in adults vary widely. Many studies have been carried out to identify and quantify factors that influence outcomes. This paper adds a new dimension to pre-existing literature. DESIGN: Single center retrospective cohort study. SETTING: University Medical Center Utrecht, The Netherlands. PARTICIPANTS: 428 adults with bilateral severe-to-profound sensorineural hearing loss, unilaterally implanted between February 1988 and March 2014. MAIN OUTCOME MEASURES: Univariable and multivariable linear regression analyses was carried out to identify factors that may influence outcomes from cochlear implantation. Consonant-vowel-consonant' word scores (CNCs) were recorded pre- and post-implant and were used as outcome measures in two groups of patients (pre- and postlingually deafened adults). As an added dimension, multiple imputation was implemented and evaluated to tackle 4% (17/407) missing data. RESULTS: For postlinguals, pre-implant speech perception score and age at onset of deafness are positive predictors and meningitis and otosclerosis as cause of deafness are negative predictors of post-implant speech perception. This model accounted for 26% of variance. For prelinguals, pre-implant speech perception score is the only strong positive predictor (Beta 0.524; p<0.001). This model accounted for 31% of variance. Age at implantation was not a significant predictor in either group. CONCLUSIONS: Speech perception is predicted by pre-implant speech perception, age at onset of deafness and etiology (meningitis and otosclerosis) for postlinguals and solely pre-implant speech perception for prelinguals. Age at implantation is of lesser importance in predicting speech perception outcome post-implant. Multiple imputation is a useful statistical techniques when analysing incomplete data sets. This article is protected by copyright. All rights reserved

Towards Clinical Application of Neurotrophic Factors to the Auditory Nerve; Assessment of Safety and Efficacy by a Systematic Review of Neurotrophic Treatments in Humans

Animal studies have evidenced protection of the auditory nerve by exogenous neurotrophic factors. In order to assess clinical applicability of neurotrophic treatment of the auditory nerve, the safety and efficacy of neurotrophic therapies in various human disorders were systematically reviewed. Outcomes of our literature search included disorder, neurotrophic factor, administration route, therapeutic outcome, and adverse event. From 2103 articles retrieved, 20 randomized controlled trials including 3974 patients were selected. Amyotrophic lateral sclerosis (53%) was the most frequently reported indication for neurotrophic therapy followed by diabetic polyneuropathy (28%). Ciliary neurotrophic factor (50%), nerve growth factor (24%) and insulin-like growth factor (21%) were most often used. Injection site reaction was a frequently occurring adverse event (61%) followed by asthenia (24%) and gastrointestinal disturbances (20%). Eighteen out of 20 trials deemed neurotrophic therapy to be safe, and six out of 17 studies concluded the neurotrophic therapy to be effective. Positive outcomes were generally small or contradicted by other studies. Most non-neurodegenerative diseases treated by targeted deliveries of neurotrophic factors were considered safe and effective. Hence, since local delivery to the cochlea is feasible, translation from animal studies to human trials in treating auditory nerve degeneration seems promising

Tinnitus after Simultaneous and Sequential Bilateral Cochlear Implantation

ImportanceThere is an ongoing global discussion on whether or not bilateral cochlear implantation should be standard care for bilateral deafness. Contrary to unilateral cochlear implantation, however, little is known about the effect of bilateral cochlear implantation on tinnitus.ObjectiveTo investigate tinnitus outcomes 1 year after bilateral cochlear implantation. Secondarily, to compare tinnitus outcomes between simultaneous and sequential bilateral cochlear implantation and to investigate long-term follow-up (3 years).Study designThis study is a secondary analysis as part of a multicenter randomized controlled trial.MethodsThirty-eight postlingually deafened adults were included in the original trial, in which the presence of tinnitus was not an inclusion criterion. All participants received cochlear implants (CIs) because of profound hearing loss. Nineteen participants received bilateral CIs simultaneously and 19 participants received bilateral CIs sequentially with an inter-implant interval of 2 years. The prevalence and severity of tinnitus before and after simultaneous and sequential bilateral cochlear implantation were measured preoperatively and each year after implantation with the Tinnitus Handicap Inventory (THI) and Tinnitus Questionnaire (TQ).ResultsThe prevalence of preoperative tinnitus was 42% (16/38). One year after bilateral implantation, there was a median difference of −8 (inter-quartile range (IQR): −28 to 4) in THI score and −9 (IQR: −17 to −9) in TQ score in the participants with preoperative tinnitus. Induction of tinnitus occurred in five participants, all in the simultaneous group, in the year after bilateral implantation. Although the preoperative and also the postoperative median THI and TQ scores were higher in the simultaneous group, the median difference scores were equal in both groups. In the simultaneous group, tinnitus scores fluctuated in the 3 years after implantation. In the sequential group, four patients had an additional benefit of the second CI: a total suppression of tinnitus compared with their unilateral situation.ConclusionWhile bilateral cochlear implantation can have a positive effect on preoperative tinnitus complaints, the induction of (temporary or permanent) tinnitus was also reported.Clinical Trial RegistrationDutch Trial Register NTR1722

Tinnitus after Simultaneous and Sequential Bilateral Cochlear Implantation

Importance: There is an ongoing global discussion on whether or not bilateral cochlear implantation should be standard care for bilateral deafness. Contrary to unilateral cochlear implantation, however, little is known about the effect of bilateral cochlear implantation on tinnitus. Objective: To investigate tinnitus outcomes 1 year after bilateral cochlear implantation. Secondarily, to compare tinnitus outcomes between simultaneous and sequential bilateral cochlear implantation and to investigate long-term follow-up (3 years). Study design: This study is a secondary analysis as part of a multicenter randomized controlled trial. Methods: Thirty-eight postlingually deafened adults were included in the original trial, in which the presence of tinnitus was not an inclusion criterion. All participants received cochlear implants (CIs) because of profound hearing loss. Nineteen participants received bilateral CIs simultaneously and 19 participants received bilateral CIs sequentially with an inter-implant interval of 2 years. The prevalence and severity of tinnitus before and after simultaneous and sequential bilateral cochlear implantation were measured preoperatively and each year after implantation with the Tinnitus Handicap Inventory (THI) and Tinnitus Questionnaire (TQ). Results: The prevalence of preoperative tinnitus was 42% (16/38). One year after bilateral implantation, there was a median difference of -8 (inter-quartile range (IQR): -28 to 4) in THI score and -9 (IQR: -17 to -9) in TQ score in the participants with preoperative tinnitus. Induction of tinnitus occurred in five participants, all in the simultaneous group, in the year after bilateral implantation. Although the preoperative and also the postoperative median THI and TQ scores were higher in the simultaneous group, the median difference scores were equal in both groups. In the simultaneous group, tinnitus scores fluctuated in the 3 years after implantation. In the sequential group, four patients had an additional benefit of the second CI: a total suppression of tinnitus compared with their unilateral situation. Conclusion: While bilateral cochlear implantation can have a positive effect on preoperative tinnitus complaints, the induction of (temporary or permanent) tinnitus was also reported. Clinical Trial Registration: Dutch Trial Register NTR1722