Pediatric Bilateral Sensorineural Hearing Loss: Minimum Test Battery and Referral Criteria for Cochlear Implant Candidacy Evaluation.

Among the various cochlear implant systems approved by the Food and Drug Administration, current labeling for pediatric usage encompasses (1) bilateral profound bilateral sensorineural hearing loss in children aged 9 to 24 months and bilateral severe to profound sensorineural hearing loss in children older than 2 years; (2) use of appropriately fitted hearing aids for 3 months (this can be waived if there is evidence of ossification); and (3) demonstration of limited progress with auditory, speech, and language development. Pediatric guidelines require children to have significantly worse speech understanding before qualifying for cochlear implantation. The early years of life have been shown to be critical for speech and language development, and auditory deprivation is especially detrimental during this crucial time.Level of evidence: 2.

Unilateral Cochlear Implants for Severe, Profound, or Moderate Sloping to Profound Bilateral Sensorineural Hearing Loss: A Systematic Review and Consensus Statements.

Importance: Cochlear implants are a treatment option for individuals with severe, profound, or moderate sloping to profound bilateral sensorineural hearing loss (SNHL) who receive little or no benefit from hearing aids; however, cochlear implantation in adults is still not routine. Objective: To develop consensus statements regarding the use of unilateral cochlear implants in adults with severe, profound, or moderate sloping to profound bilateral SNHL. Design, Setting, and Participants: This study was a modified Delphi consensus process that was informed by a systematic review of the literature and clinical expertise. Searches were conducted in the following databases: (1) MEDLINE In-Process & Other Non-Indexed Citations and Ovid MEDLINE, (2) Embase, and (3) the Cochrane Library. Consensus statements on cochlear implantation were developed using the evidence identified. This consensus process was relevant for the use of unilateral cochlear implantation in adults with severe, profound, or moderate sloping to profound bilateral SNHL. The literature searches were conducted on July 18, 2018, and the 3-step Delphi consensus method took place over the subsequent 9-month period up to March 30, 2019. Main Outcomes and Measures: A Delphi consensus panel of 30 international specialists voted on consensus statements about cochlear implantation, informed by an SR of the literature and clinical expertise. This vote resulted in 20 evidence-based consensus statements that are in line with clinical experience. A modified 3-step Delphi consensus method was used to vote on and refine the consensus statements. This method consisted of 2 rounds of email questionnaires and a face-to-face meeting of panel members at the final round. All consensus statements were reviewed, discussed, and finalized at the face-to-face meeting. Results: In total, 6492 articles were identified in the searches of the electronic databases. After removal of duplicate articles, 74 articles fulfilled all of the inclusion criteria and were used to create the 20 evidence-based consensus statements. These 20 consensus statements on the use of unilateral cochlear implantation in adults with SNHL were relevant to the following 7 key areas of interest: level of awareness of cochlear implantation (1 consensus statement); best practice clinical pathway from diagnosis to surgery (3 consensus statements); best practice guidelines for surgery (2 consensus statements); clinical effectiveness of cochlear implantation (4 consensus statements); factors associated with postimplantation outcomes (4 consensus statements); association between hearing loss and depression, cognition, and dementia (5 consensus statements); and cost implications of cochlear implantation (1 consensus statement). Conclusions and Relevance: These consensus statements represent the first step toward the development of international guidelines on best practices for cochlear implantation in adults with SNHL. Further research to develop consensus statements for unilateral cochlear implantation in children, bilateral cochlear implantation, combined electric-acoustic stimulation, unilateral cochlear implantation for single-sided deafness, and asymmetrical hearing loss in children and adults may be beneficial for optimizing hearing and quality of life for these patients.

Recommendations for Measuring the Electrically Evoked Compound Action Potential in Children With Cochlear Nerve Deficiency.

OBJECTIVES: This study reports a method for measuring the electrically evoked compound action potential (eCAP) in children with cochlear nerve deficiency (CND). DESIGN: This method was developed based on experience with 50 children with CND who were Cochlear Nucleus cochlear implant users. RESULTS: This method includes three recommended steps conducted with recommended stimulating and recording parameters: initial screen, pulse phase duration optimization, and eCAP threshold determination (i.e., identifying the lowest stimulation level that can evoke an eCAP). Compared with the manufacturer-default parameters, the recommended parameters used in this method yielded a higher success rate for measuring the eCAP in children with CND. CONCLUSIONS: The eCAP can be measured successfully in children with CND using recommended parameters. This specific method is suitable for measuring the eCAP in children with CND in clinical settings. However, it is not suitable for intraoperative eCAP recordings due to the extensive testing time required.

Pediatric cochlear implantation: A quarter century in review.

Objective: To review the growth of a pediatric cochlear implant (CI) program at one large tertiary care medical center over a 25-year period in order to (1) describe the population of pediatric cochlear implant recipients, (2) document word recognition outcomes, and (3) describe changes in candidacy criteria over time. Design: A retrospective review of population demographics and trends included etiology of hearing loss, device use and type, expansion of inclusion criteria, and word recognition outcomes. Results: Ninety-one percent of the children studied were from North Carolina and reflect the ethnic distribution of the state. The population is heterogeneous for etiology and the presence of syndromes and/or co-morbidities. A trend of lower age of implant and greater residual hearing was documented overtime. As a single metric, monosyllable word recognition for the children assessed is good with the mean CNC test word score of 76.13% (range 0-100, S.D = 19.94). Conclusions: Pediatric cochlear implant candidacy criteria have evolved despite no change in FDA-approved regulations since 2000. There is great diversity among recipients but word recognition outcomes are generally good in this population and have improved over time. Professionals who may refer children for cochlear implantation should be aware of current clinical practices and general outcomes.

Remote Programming of Cochlear Implants.

OBJECTIVE: This study investigated the safety and efficacy of remote programming of cochlear implants. STUDY DESIGN: Single-subject design SETTING:: Four North American clinical sites PATIENTS:: Forty cochlear implant recipients aged 12 years or older INTERVENTION:: Subjects had their cochlear implants programmed at a location that was remote from their audiologist using telecommunication with and without the support of a facilitator. MAIN OUTCOME MEASURES: Consonant-Nucleus-Consonant (CNC) word scores and the Speech, Spatial, and Qualities of Hearing Scale-C (SSQ-C) were compared using the subject's in-office MAP (program) and MAPs programmed remotely with and without the assistance of a facilitator. Additional subjective preference data were gathered from subjects and audiologists via questionnaires. RESULTS: MAPs programmed via the three different models did not yield significantly different group mean CNC word scores. No device/procedure-related adverse events occurred. SSQ-C questionnaire results indicated that recipients received similar subjective benefit from familiar in-office, remote-facilitated, and remote-unassisted MAPs. CONCLUSIONS: Remote programming is an effective means of cochlear implant service delivery. The practice was approved by the FDA on November 17, 2017 supported by the results of this study.

Hearing Preservation in Pediatric Recipients of Cochlear Implants.

OBJECTIVE: To determine factors that influence low-frequency hearing preservation following pediatric cochlear implantation and compare hearing preservation outcomes between 20 and 24 mm depth lateral wall electrodes. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary academic referral center. PATIENTS: Pediatric cochlear implant recipients (under the age of 18) who presented preoperatively with a low-frequency pure tone average (LFPTA; 125, 250 and 500 Hz) ≤ 70 dB HL. INTERVENTION: Cochlear implantation MAIN OUTCOME MEASURES:: Multiple logistic regression evaluating the influence of variables on change in LFPTA including preoperative low-frequency hearing, lateral wall or perimodiolar electrode, progressive vs stable hearing, side, time from surgery, and the presence or the absence of enlarged vestibular aqueduct. A second analysis reviews the 12-month postactivation hearing preservation of a subset of subjects implanted with modern lateral wall electrodes. RESULTS: A total of 105 subjects were included from the last 10 years for our multiple logistic regression analysis. This demonstrated a significant correlation of poorer preoperative low-frequency hearing with change in LFPTA. A significant negative effect of electrode type, specifically perimodiolar electrodes was also seen. Forty-five subjects from the last 3 years undergoing cochlear implantation with a lateral wall electrode demonstrated an overall 12-month preservation rate (LFPTA < 90 dB) of 82%. Differences in preservation rates existed between different electrodes. CONCLUSION: Preservation of low-frequency hearing following cochlear implantation is predicted both by preoperative low-frequency hearing as well as type of electrode implanted. Consistent low-frequency hearing preservation is possible in pediatric subjects receiving lateral wall electrodes, although differences exist between electrode types.

Electric-Acoustic Stimulation Outcomes in Children.

OBJECTIVES: This study investigates outcomes in children fit with electric-acoustic stimulation (EAS) and addresses three main questions: (1) Are outcomes with EAS superior to outcomes with conventional electric-only stimulation in children? (2) Do children with residual hearing benefit from EAS and conventional electric-only stimulation when compared with the preoperative hearing aid (HA) condition? (3) Can children with residual hearing derive benefit from EAS after several years of listening with conventional electric-only stimulation? DESIGN: Sixteen pediatric cochlear implant (CI) recipients between 4 and 16 years of age with an unaided low-frequency pure tone average of 75 dB HL in the implanted ear were included in two study arms. Arm 1 included new recipients, and Arm 2 included children with at least 1 year of CI experience. Using a within-subject design, participants were evaluated unilaterally with the Consonant-Nucleus-Consonant (CNC) word list in quiet and the Baby Bio at a +5 dB SNR using an EAS program and a conventional full electric (FE) program. Arm 1 participants' scores were also compared with preoperative scores. RESULTS: Speech perception outcomes were statistically higher with the EAS program than the FE program. For new recipients, scores were significantly higher with EAS than preoperative HA scores for both the CNC and Baby Bio in noise; however, after 6 months of device use, results in the FE condition were not significantly better than preoperative scores. Long-term FE users benefited from EAS over their FE programs based on CNC word scores. CONCLUSIONS: Whether newly implanted or long-term CI users, children with residual hearing after CI surgery can benefit from EAS. Cochlear implantation with EAS fitting is a viable option for children with HAs who have residual hearing but have insufficient access to high-frequency sounds and poor speech perception.

Residual Cochlear Function in Adults and Children Receiving Cochlear Implants: Correlations With Speech Perception Outcomes.

OBJECTIVES: Variability in speech perception outcomes with cochlear implants remains largely unexplained. Recently, electrocochleography, or measurements of cochlear potentials in response to sound, has been used to assess residual cochlear function at the time of implantation. Our objective was to characterize the potentials recorded preimplantation in subjects of all ages, and evaluate the relationship between the responses, including a subjective estimate of neural activity, and speech perception outcomes. DESIGN: Electrocochleography was recorded in a prospective cohort of 284 candidates for cochlear implant at University of North Carolina (10 months to 88 years of ages). Measurement of residual cochlear function called the "total response" (TR), which is the sum of magnitudes of spectral components in response to tones of different stimulus frequencies, was obtained for each subject. The TR was then related to results on age-appropriate monosyllabic word score tests presented in quiet. In addition to the TR, the electrocochleography results were also assessed for neural activity in the forms of the compound action potential and auditory nerve neurophonic. RESULTS: The TR magnitude ranged from a barely detectable response of about 0.02 µV to more than 100 µV. In adults (18 to 79 years old), the TR accounted for 46% of variability in speech perception outcome by linear regression (r = 0.46; p < 0.001). In children between 6 and 17 years old, the variability accounted for was 36% (p < 0.001). In younger children, the TR accounted for less of the variability, 15% (p = 0.012). Subjects over 80 years old tended to perform worse for a given TR than younger adults at the 6-month testing interval. The subjectively assessed neural activity did not increase the information compared with the TR alone, which is primarily composed of the cochlear microphonic produced by hair cells. CONCLUSIONS: The status of the auditory periphery, particularly of hair cells rather than neural activity, accounts for a large fraction of variability in speech perception outcomes in adults and older children. In younger children, the relationship is weaker, and the elderly differ from other adults. This simple measurement can be applied with high throughput so that peripheral status can be assessed to help manage patient expectations, create individually-tailored treatment plans, and identify subjects performing below expectations based on residual cochlear function.

Longitudinal Changes in Electrically Evoked Auditory Event-Related Potentials in Children With Auditory Brainstem Implants: Preliminary Results Recorded Over 3 Years.

OBJECTIVES: This preliminary study aimed (1) to assess longitudinal changes in electrically evoked auditory event-related potentials (eERPs) in children with auditory brainstem implants (ABIs) and (2) to explore whether these changes could be accounted for by maturation in the central auditory system of these patients. DESIGN: Study participants included 5 children (S1 to S5) with an ABI in the affected ear. The stimulus was a train of electrical pulses delivered to individual ABI electrodes via a research interface. For each subject, the eERP was repeatedly measured in multiple test sessions scheduled over up to 41 months after initial device activation. Longitudinal changes in eERPs recorded for each ABI electrode were evaluated using intraclass correlation tests for each subject. RESULTS: eERPs recorded in S1 showed notable morphological changes for five ABI electrodes over 41 months. In parallel, signs or symptoms of nonauditory stimulation elicited by these electrodes were observed or reported at 41 months. eERPs could not be observed in S2 after 9 months of ABI use but were recorded at 12 months after initial stimulation. Repeatable eERPs were recorded in S3 in the first 9 months. However, these responses were either absent or showed remarkable morphological changes at 30 months. Longitudinal changes in eERP waveform morphology recorded in S4 and S5 were also observed. CONCLUSIONS: eERP responses in children with ABIs could change over a long period of time. Maturation of the central auditory system could not fully account for these observed changes. Children with ABIs need to be closely monitored for potential changes in auditory perception and unfavorable nonauditory sensations. Neuroimaging correlates are needed to better understand the emergence of nonauditory stimulation over time in these children.

The Electrically Evoked Auditory Change Complex Evoked by Temporal Gaps Using Cochlear Implants or Auditory Brainstem Implants in Children With Cochlear Nerve Deficiency.

OBJECTIVES: This study aimed to (1) establish the feasibility of measuring the electrically evoked auditory change complex (eACC) in response to temporal gaps in children with cochlear nerve deficiency (CND) who are using cochlear implants (CIs) and/or auditory brainstem implants (ABIs); and (2) explore the association between neural encoding of, and perceptual sensitivity to, temporal gaps in these patients. DESIGN: Study participants included 5 children (S1 to S5) ranging in age from 3.8 to 8.2 years (mean: 6.3 years) at the time of testing. All subjects were unilaterally implanted with a Nucleus 24M ABI due to CND. For each subject, two or more stimulating electrodes of the ABI were tested. S2, S3, and S5 previously received a CI in the contralateral ear. For these 3 subjects, at least two stimulating electrodes of their CIs were also tested. For electrophysiological measures, the stimulus was an 800-msec biphasic pulse train delivered to individual electrodes at the maximum comfortable level (C level). The electrically evoked responses, including the onset response and the eACC, were measured for two stimulation conditions. In the standard condition, the 800-msec pulse train was delivered uninterrupted to individual stimulating electrodes. In the gapped condition, a temporal gap was inserted into the pulse train after 400 msec of stimulation. Gap durations tested in this study ranged from 2 up to 128 msec. The shortest gap that could reliably evoke the eACC was defined as the objective gap detection threshold (GDT). For behavioral GDT measures, the stimulus was a 500-msec biphasic pulse train presented at the C level. The behavioral GDT was measured for individual stimulating electrodes using a one-interval, two-alternative forced-choice procedure. RESULTS: The eACCs to temporal gaps were recorded successfully in all subjects for at least one stimulating electrode using either the ABI or the CI. Objective GDTs showed intersubject variations, as well as variations across stimulating electrodes of the ABI or the CI within each subject. Behavioral GDTs were measured for one ABI electrode in S2 and for multiple ABI and CI electrodes in S5. All other subjects could not complete the task. S5 showed smaller behavioral GDTs for CI electrodes than those measured for ABI electrodes. One CI and two ABI electrodes in S5 showed comparable objective and behavioral GDTs. In contrast, one CI and two ABI electrodes in S5 and one ABI electrode in S2 showed measurable behavioral GDTs but no identifiable eACCs. CONCLUSIONS: The eACCs to temporal gaps were recorded in children with CND using either ABIs or CIs. Both objective and behavioral GDTs showed inter- and intrasubject variations. Consistency between results of eACC recordings and psychophysical measures of GDT was observed for some but not all ABI or CI electrodes in these subjects.

Pediatric Auditory Brainstem Implantation: Surgical, Electrophysiologic, and Behavioral Outcomes.

OBJECTIVES: The objectives of this study were to demonstrate the safety of auditory brainstem implant (ABI) surgery and document the subsequent development of auditory and spoken language skills in children without neurofibromatosis type II (NFII). DESIGN: A prospective, single-subject observational study of ABI in children without NFII was undertaken at the University of North Carolina at Chapel Hill. Five children were enrolled under an investigational device exemption sponsored by the investigators. Over 3 years, patient demographics, medical/surgical findings, complications, device mapping, electrophysiologic measures, audiologic outcomes, and speech and language measures were collected. RESULTS: Five children without NFII have received ABIs to date without permanent medical sequelae, although 2 children required treatment after surgery for temporary complications. All children wear their device daily, and the benefits of sound awareness have developed slowly. Intra-and postoperative electrophysiologic measures augmented surgical placement and device programming. The slow development of audition skills precipitated limited changes in speech production but had little impact on growth in spoken language. CONCLUSIONS: ABI surgery is safe in young children without NFII. Benefits from device use develop slowly and include sound awareness and the use of pattern and timing aspects of sound. These skills may augment progress in speech production but progress in language development is dependent upon visual communication. Further monitoring of this cohort is needed to better delineate the benefits of this intervention in this patient population.

Audiological Outcomes and Map Characteristics in Children With Perimodiolar and Slim Straight Array Cochlear Implants in Opposite Ears.

OBJECTIVE: To identify differences in outcomes and map characteristics in pediatric bilateral cochlear implants with modiolar conforming and lateral wall arrays in opposite ears. STUDY DESIGN: Retrospective case series. SETTING: Tertiary care pediatric referral center. PATIENTS: Fourteen children who received a perimodiolar array in one ear and a slim straight array in the opposite ear in sequential surgeries. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Consonant-nucleus-consonant test (CNC) word recognition score, battery life, power levels, electrical compound action potential (ECAP) thresholds, and electrical threshold and comfort charge levels. RESULTS: Speech perception outcomes were poorer in the lateral wall ears than the perimodiolar ears, and scores in the bilateral condition were better than with the lateral wall device alone. Sequential placement was a factor with differences in preoperative candidacy time correlating with greater difference in speech perception. There was no difference in charge levels between ears, in spite of higher ECAP threshold values for the lateral wall devices. CONCLUSION: While bilateral speech perception was good, speech perception with the lateral wall device alone was poorer. This cannot be explained solely by the device, as differences in preoperative candidacy time were a significant factor. ECAP thresholds are significantly higher for lateral wall electrodes, but that did not translate in to higher psychophysical measurements.

Clinical role of electrocochleography in children with auditory neuropathy spectrum disorder.

OBJECTIVES: To assess electrocochleography (ECochG) to tones as an instrument to account for CI speech perception outcomes in children with auditory neuropathy spectrum disorder (ANSD). MATERIALS & METHODS: Children (<18 years) receiving CIs for ANSD (n = 30) and non-ANSD (n = 74) etiologies of hearing loss were evaluated with ECochG using tone bursts (0.25-4 kHz). The total response (TR) is the sum of spectral peaks of responses across frequencies. The compound action potential (CAP) and the auditory nerve neurophonic (ANN) in ECochG waveforms were used to estimate nerve activity and calculate nerve score. Performance on open-set monosyllabic word tests was the outcome measure. Standard statistical methods were applied. RESULTS: On average, TR was larger in ANSD than in non-ANSD subjects. Most ANSD (73.3%) and non-ANSD (87.8%) subjects achieved open-set speech perception; TR accounted for 33% and 20% of variability in the outcomes, respectively. In the ANSD group, the PTA accounted for 69.3% of the variability, but there was no relationship with outcomes in the non-ANSD group. In both populations, nerve score was sensitive in identifying subjects at risk for not acquiring open-set speech perception, while the CAP and the ANN were more specific. CONCLUSION: In both subject groups, the TRs correlated with outcomes but these measures were notably larger in the ANSD group. There was also strong correlation between PTA and speech perception outcome in ANSD group. In both subject populations, weaker evidence of neural activity was related to failure to achieve open-set speech perception.

The Electrically Evoked Compound Action Potential: From Laboratory to Clinic.

The electrically evoked compound action potential (eCAP) represents the synchronous firing of a population of electrically stimulated auditory nerve fibers. It can be directly recorded on a surgically exposed nerve trunk in animals or from an intra-cochlear electrode of a cochlear implant. In the past two decades, the eCAP has been widely recorded in both animals and clinical patient populations using different testing paradigms. This paper provides an overview of recording methodologies and response characteristics of the eCAP, as well as its potential applications in research and clinical situations. Relevant studies are reviewed and implications for clinicians are discussed.

Considerations for Pediatric Cochlear Implant Recipients With Unilateral or Asymmetric Hearing Loss: Assessment, Device Fitting, and Habilitation.

PURPOSE: The purpose of this clinical report is to present case studies of children who are nontraditional candidates for cochlear implantation because they have significant residual hearing in 1 ear and to describe outcomes and considerations for their audiological management and habilitation. METHOD: Case information is presented for 5 children with profound hearing loss in 1 ear and normal or mild-to-moderate hearing loss in the opposite ear and who have undergone unilateral cochlear implantation. Pre- and postoperative assessments were performed per typical clinic routines with modifications described. Postimplant habilitation was customized for each recipient using a combination of traditional methods, newer technologies, and commercial materials. RESULTS: The 5 children included in this report are consistent users of their cochlear implants and demonstrate speech recognition in the implanted ear when isolated from the better hearing ear. CONCLUSIONS: Candidacy criteria for cochlear implantation are evolving. Children with single-sided deafness or asymmetric hearing loss who have traditionally not been considered candidates for cochlear implantation should be evaluated on a case-by-case basis. Audiological management of these recipients is not vastly different compared with children who are traditional cochlear implant recipients. Assessment and habilitation techniques must be modified to isolate the implanted ear to obtain accurate results and to provide meaningful therapeutic intervention.

Electrically Evoked Auditory Event-Related Responses in Patients with Auditory Brainstem Implants: Morphological Characteristics, Test-Retest Reliability, Effects of Stimulation Level, and Association with Auditory Detection.

OBJECTIVE: This study aimed to (1) characterize morphological characteristics of the electrically evoked cortical auditory event-related potentials (eERPs) and explore the potential association between onset eERP morphology and auditory versus nonauditory stimulation; (2) assess test-retest reliability of onset eERPs; (3) investigate effects of stimulation level on onset eERPs; and (4) explore the feasibility of using the onset eERP to estimate the lowest stimulation level that can be detected for individual stimulating electrodes in patients with auditory brainstem implants (ABIs). DESIGN: Study participants included 5 children (S1 to S5) and 2 adults (S6 to S7) with unilateral Cochlear Nucleus 24M ABIs. Pediatric ABI recipients ranged in age from 2.6 to 10.2 years (mean: 5.2 years) at the time of testing. S6 and S7 were 21.2 and 24.6 years of age at the time of testing, respectively. S6 and S7 were diagnosed with neurofibromatosis II (NF2) and implanted with an ABI after a surgical removal of the tumors. All pediatric subjects received ABIs after being diagnosed with cochlear nerve deficiency. The lowest stimulation level that could be detected (behavioral T level) and the estimated maximum comfortable level (C level) was measured for individual electrodes using clinical procedures. For electrophysiological measures, the stimulus was a 100-msec biphasic pulse train that was delivered to individual electrodes in a monopolar-coupled stimulation mode at stimulation levels ranging from subthreshold to C levels. Electrophysiological recordings of the onset eERP were obtained in all subjects. For studies evaluating the test-retest reliability of the onset eERP, responses were measured using the same set of parameters in two test sessions. The time interval between test sessions ranged from 2 to 6 months. The lowest stimulation level that could evoke the onset eERP was defined as the objective T level. RESULTS: Onset eERPs were recorded in all subjects tested in this study. Inter- and intrasubject variations in morphological characteristics of onset eERPs were observed. Onset eERPs with complex waveforms were recorded for electrodes that evoked nonauditory sensations, based on feedback from subjects, as well as for electrodes without any indications of nonauditory stimulations. Onset eERPs in patients with ABIs demonstrated good test-retest reliability. Increasing stimulation levels resulted in increased eERP amplitudes but showed inconsistent effects on response latencies in patients with ABIs. Objective and behavioral T levels were correlated. CONCLUSIONS: eERPs could be recorded in both non-NF2 and NF2 patients with ABIs. eERPs in both ABI patient groups show inter- and intrasubject variations in morphological characteristics. However, onset eERPs measured within the same subject in this study tended to be stable across study sessions. The onset eERP can potentially be used to estimate behavioral T levels in patients with ABIs. Further studies with more adult ABI recipients are warranted to investigate whether the onset eERP can be used to identify electrodes with nonauditory stimulations.

The effect of interdevice interval on speech perception performance among bilateral, pediatric cochlear implant recipients.

OBJECTIVES/HYPOTHESIS: To determine if prolongation of the interdevice interval in children receiving bilateral cochlear implants adversely affects speech perception outcomes. STUDY DESIGN: Retrospective chart review. METHODS: Retrospective review of our pediatric cochlear implant database was performed. Children who had undergone revision surgery or had less than 12 months listening experience with either the first or second implant were excluded. The interdevice interval, best Phonetically Balanced Kindergarten word lists (PBK) score from each ear, and demographic data about each patient were collected. A ratio of PBK was generated (PBK second side/PBK first side) to minimize potential confounding from other individual patient factors that affect speech outcomes. RESULTS: Two hundred forty children met the study criteria. Mean age at first cochlear implantation (CI) was 3.2 years (0.6-17.9), and the second was 6.6 years (0.8-22.4). Mean best PBK score from the first CI side was 83.8% (0-100), and the second was 67.5% (0-100) (P < .001). When the PBK ratio was plotted against interdevice interval, R(2) was 0.47 (P < .001). When analyzed for hearing stability, those with a progressive loss history demonstrated less influence of prolonged interdevice interval on performance. Multivariate analysis did not identify other factors influencing the ratio. A line of best fit for those with stable hearing loss suggested best outcomes were with an interdevice interval less than 3 to 4 years. Beyond 7 to 8 years, very few achieved useful speech recognition from the second CI. CONCLUSIONS: Where possible, the second implant should be received within 3 to 4 years of the first to maximize outcome in those with stable, severe to profound sensorineural hearing loss. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:2389-2394, 2016.

The electrically evoked cortical auditory event-related potential in children with auditory brainstem implants.

OBJECTIVE: This study explored the feasibility of measuring electrically evoked cortical auditory event-related potentials (eERPs) in children with auditory brainstem implants (ABIs). DESIGN: Five children with unilateral ABIs ranging in age from 2.8 to 10.2 years (mean: 5.2 years) participated in this study. The stimulus was a 100-msec biphasic pulse train that was delivered to individual electrodes in a monopolar stimulation mode. Electrophysiological recordings of the onset eERP were conducted in all subjects. RESULTS: The onset eERP was recorded in four subjects who demonstrated auditory perception. These eERP responses showed variations in waveform morphology across subjects and stimulating electrode locations. No eERPs were observed in one subject who received no auditory sensation from ABI stimulation. CONCLUSIONS: eERPs can be recorded in children with ABIs who develop auditory perception. The morphology of the eERP can vary across subjects and also across stimulating electrode locations within subjects.

Intraoperative round window electrocochleography and speech perception outcomes in pediatric cochlear implant recipients.

OBJECTIVES: The goal was to measure the magnitude of cochlear responses to sound in pediatric cochlear implant recipients at the time of implantation and to correlate this magnitude with subsequent speech perception outcomes. DESIGN: A longitudinal cohort study of pediatric cochlear implant recipients was undertaken. Intraoperative electrocochleographic (ECoG) recordings were obtained from the round window in response to a frequency series at 90 dB nHL in 77 children totaling 89 ears (12 were second side surgeries) just before device insertion. The increase in intraoperative time was approximately 10 min. An ECoG "total response" metric was derived from the summed magnitudes of significant responses to the first, second, and third harmonics across a series of frequencies. A subset of these children reached at least 9 months of implant use and were old enough for the phonetically balanced kindergarten (PB-k) word test to be administered (n = 26 subjects and 28 ears). PB-k scores were compared to the ECoG total response and other biologic and audiologic variables using univariate and multiple linear regression analyses. RESULTS: ECoG responses were measurable in almost all ears (87 of 89). The range of ECoG total response covered about 60 dB (from ~0.05 to 50 µV). Analyzing individual ECoG recordings in bilaterally implanted children revealed poor concordance between the measured response in the first versus second ear implanted (r = 0.21; p = 0.13; n = 12). In a univariate linear regression, the ECoG total response was significantly correlated with PB-k scores in the subset of 26 subjects who were able to be tested and accounted for 32% of the variance (p = 0.002, n = 28). Preoperative pure-tone average (PTA) accounted for slightly more of the variance (r = 0.37, p = 0.001). However, ECoG total response and PTA were significantly but only weakly correlated (r = 0.14, p = 0.001). Other significant predictors of speech performance included hearing stability (stable versus progressive) and age at testing (22 and 16% of the variance, respectively). In multivariate analyses with these four factors, the ECoG accounted for the most weight (ß = 0.36), followed by PTA (ß = 0.26). In a hierarchical multiple regression analysis, the most parsimonious models that best predicted speech perception outcomes included three variables: ECoG total response, and any two of preoperative PTA, age at testing, or hearing stability. The various three factor models each predicted approximately 50% of the variance in word scores. Without the ECoG total response, the other three factors predicted 36% of variance. CONCLUSIONS: Intraoperative round window ECoG recordings are reliably and easily obtained in pediatric cochlear implant recipients. The ECoG total response is significantly correlated with speech perception outcomes in pediatric implant recipients and can account for a comparable or greater proportion of variance in speech perception than other bio-audiologic factors. Intraoperative recordings can potentially provide useful prognostic information about acquisition of open set speech perception in implanted children.

Is "no response" on diagnostic auditory brainstem response testing an indication for cochlear implantation in children?

OBJECTIVES: To compare the results of a "no response" (NR) result on auditory brainstem response (ABR) testing with those of behavioral pure-tone audiometry and ultimate clinical tracking to cochlear implantation (CI). DESIGN: Retrospective review of pediatric patients who underwent multifrequency ABR testing in a 5 year span. Total of 1143 pediatric patients underwent ABR testing during the study period and 105 (9.2%) were identified with bilateral NR based on absent responses to both click and tone burst stimuli. For the children with NR, various clinical parameters were evaluated as these children progressed through the CI evaluation process. Children were grouped based on whether they underwent ABRs for diagnostic or for confirmatory purposes. RESULTS: Of the 105 children who met inclusion criteria, 94 had sufficient follow-up to be included in this analysis. Ninety-one (96.8%) of 94 children with bilateral NR ABRs were ultimately recommended for and received a CI. Three (3.2%) children were not recommended for implantation based on the presence of multiple comorbidities rather than auditory factors. None of the children (0%) had enough usable residual hearing to preclude CI. For those who had diagnostic ABRs, the average time at ABR testing was 5.4 months (SD 6.2, range 1-36) and the average time from ABR to CI was 10.78 months (SD 5.0, range 3-38). CONCLUSIONS: CI should tentatively be recommended for children with a bilateral NR result with multifrequency ABR, assuming confirmatory results with behavioral audiometric testing. Amplification trials, counseling, and auditory-based intervention therapy should commence but not delay surgical intervention, as it does not appear to change the eventual clinical course. Children not appropriate for this "fast-tracking" to implantation might include those with significant comorbidities, auditory neuropathy spectrum disorder, and unreliable or poorly correlated results on behavioral audiometric testing.