Delaying Cochlear Implantation Impacts Postoperative Speech Perception of Nontraditional Pediatric Candidates.

INTRODUCTION: As pediatric cochlear implant (CI) candidacy expands, children with greater degrees of residual hearing are receiving CIs. These nontraditional candidates have audiometric thresholds that meet adult manufacturer labeling but are better than current pediatric guidelines allow. The purpose of this study was to determine the impact of delayed cochlear implantation on speech perception in nontraditional pediatric CI recipients. METHODS: Pediatric CI recipients with a history of progressive hearing loss and a preoperative 4-frequency pure-tone average of ≤75 dB HL at the time of implantation were considered for this retrospective study. Preoperative serial audiograms and word recognition scores were reviewed, and a method was created to establish a date when each individual ear 1st met nontraditional candidacy. The length of time between the date of candidacy and implantation was calculated and defined as the "delay time." A multiple linear regression investigated delay time, age at surgery, surgery type (1st vs. 2nd side), and array type as predictive factors of maximum postoperative Consonant-Nucleus-Consonant (CNC) word scores. A one-way ANCOVA was performed comparing the postoperative CNC scores between subjects grouped by delay time. RESULTS: A significant regression was found (F(4, 38) = 5.167, p = 0.002, R2 = 0.353). Both age at implantation (p = 0.023) and delay time (p = 0.002) predicted CNC word scores. Longer delay time was associated with poorer word recognition scores, while older age at implantation correlated with higher CNC word scores in this progressive hearing loss group. A significant difference was noted between subjects implanted with <1 year of delay and those with 3 or more years of delay (p = 0.003). All ears implanted within a year of candidacy achieved word recognition abilities that are generally accepted as above average (M = 84.91). CONCLUSION: CI candidacy for adults has evolved to allow for greater degrees of residual hearing, while audiometric guidelines for children have not changed since 2000. Our findings suggest that delay of cochlear implantation, even for children with significant levels of residual hearing, leads to poorer outcomes. Modified candidacy guidelines for children should be established to expedite referral to multidisciplinary CI teams and minimize delays in this population.

Cochlear implantation in children with auditory neuropathy spectrum disorder.

OBJECTIVE: To report the patient's characteristics, preoperative audiological profiles, surgical outcomes, and postoperative performance for children with auditory neuropathy spectrum disorder (ANSD) who ultimately received cochlear implants (CIs). DESIGN: Prospective, longitudinal study of children with ANSD who received CIs after a stepwise management protocol that included electrophysiologic and medical assessment, documentation of behavioral audiometric thresholds and subsequent fitting of amplification according to Desired Sensation Level targets, auditory-based intervention with careful monitoring of skills development and communication milestones, and finally implantation when progress with the use of acoustic amplification was insufficient. RESULTS: Of 140 children with ANSD, 52 (37%) received CIs in their affected ears (mean duration of use of 41 mos). Many of these children were born prematurely (42%) and impacted by a variety of medical comorbidities. More than one third (38%) had abnormal findings on preoperative magnetic resonance imaging of the brain and inner ear, and 81% had a greater than severe (>70 dB HL) degree of hearing loss before implantation. Although 50% of the implanted children with ANSD demonstrated open-set speech perception abilities after implantation, nearly 30% of them with >6 months of implant experience were unable to participate in this type of testing because of their young age or developmental delays. No child with cochlear nerve deficiency (CND) in their implanted ear achieved open-set speech perception abilities. In a subgroup of children, good open-set speech perception skills were associated with robust responses elicited on electrical-evoked intracochlear compound action potential testing when this assessment was possible. CONCLUSIONS: This report shows that children with ANSD who receive CIs are a heterogeneous group with a wide variety of impairments. Although many of these children may ultimately benefit from implantation, some will not, presumably because of a lack of electrical-induced neural synchronization, the detrimental effects of their other associated conditions, or a combination of factors. When preoperative magnetic resonance imaging reveals central nervous system pathology, this portends a poor prognosis for the development of open-set speech perception, particularly when CND is evident. These results also show that electrical-evoked intracochlear compound action potential testing may help identify those children who will develop good open-set speech perception. Instead of recommending CI for all children with electrophysiologic evidence of ANSD, the stepwise management procedure described herein allows for the identification of children who may benefit from amplification, those who are appropriate candidates for cochlear implantation, and those who, because of bilateral CND, may not be appropriate candidates for either intervention.

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.

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.