Systematic Review on Late Cochlear Implantation in Early-Deafened Adults and Adolescents: Clinical Effectiveness.

OBJECTIVES: Cochlear implantation in early-deafened patients, implanted as adolescents or adults, is not always advised due to poor expected outcomes. In order to judge whether such reluctance is justified, the current systematic review aimed to gather all available evidence on postoperative outcomes obtained by early-deafened patients using a state-of-the art cochlear implant (CI). DESIGN: Five electronic databases (PubMed, Embase, the Cochrane library, CINAHL, and PsycInfo) were systematically searched for studies in English, French, German, or Dutch, published between 2000 and September 2017. Studies that reported pre- and postoperative outcomes on any measure of speech or sound perception, audiovisual or subjective benefit (quality of life) were included. Study quality was assessed with the Institute of Health Economics quality appraisal tool for case series studies. RESULTS: The systematic search and subsequent full-text evaluation identified 38 studies meeting the inclusion criteria. Only a limited number of studies were judged to be of high quality according to the Institute of Health Economics tool, with lack of (clear) presentation of relevant study information being a recurring problem. Twenty-five studies presented viable outcomes on open-set speech understanding in quiet: mean postoperative scores obtained with CI remained below 50% for the vast majority of studies; significant postoperative improvements were found in 16 studies, although this number might have been higher if appropriate statistical testing had been performed in all studies. Eight studies observed increased audiovisual performance after implantation, which was statistically significant in six studies. A validated measure of hearing-related quality of life was used in only 5 of the 16 studies assessing subjective outcomes, showing significant postoperative improvements for most questionnaire domains. The relation between auditory and subjective outcomes was assessed in two studies, with contradictory results. CONCLUSIONS: The current review showed that late cochlear implantation in early-deafened subjects resulted in significantly improved open-set speech perception, audiovisual speech perception, and (hearing-related) quality of life in the majority of the studies involved. Nonetheless, more and especially higher-quality research is needed in order to gain a more detailed understanding of the outcomes of cochlear implantation in this population.

Systematic Review on Late Cochlear Implantation in Early-Deafened Adults and Adolescents: Predictors of Performance.

OBJECTIVES: Early-deafened, late-implanted adolescents and adults constitute a unique group of cochlear implant (CI) users, showing a large variability in outcomes. The current systematic review aimed to determine which preimplantation factors are relevant in predicting postoperative outcomes in this patient group. DESIGN: A systematic search for studies published between 2000 and September 2017 was performed in five electronic databases (PubMed, Embase, the Cochrane library, CINAHL, and PsycInfo). Prognostic studies that assessed the relation between patient-related factors and CI outcomes in early-deafened but late-implanted adolescent and adult CI users were included. Study quality was assessed with the Quality In Prognosis Studies (QUIPS) tool. RESULTS: The systematic search and subsequent full-text evaluation identified 13 studies that had a clear prognostic study goal. Eight out of these 13 studies had a high risk of bias for at least one of the five QUIPS domains. Analysis of the outcomes identified that communication mode (in childhood), preoperative speech intelligibility, and preoperative speech recognition scores were significantly related to speech perception outcomes for this group of CI users. A number of additional factors considered worth for further investigation were also identified. CONCLUSIONS: The analysis of the studies assessing the effect of a number of patient-related factors on outcome with CI in early-deafened adolescents and adults identified three potential prognostic factors and a number of additional factors to be incorporated in future research. More high-quality prognosis studies in the investigated patient population are still needed.

Fitting prelingually deafened adult cochlear implant users based on electrode discrimination performance.

OBJECTIVE: This study investigated the hypotheses that (1) prelingually deafened CI users do not have perfect electrode discrimination ability and (2) the deactivation of non-discriminable electrodes can improve auditory performance. DESIGN: Electrode discrimination difference limens were determined for all electrodes of the array. The subjects' basic map was subsequently compared to an experimental map, which contained only discriminable electrodes, with respect to speech understanding in quiet and in noise, listening effort, spectral ripple discrimination and subjective appreciation. STUDY SAMPLE: Subjects were six prelingually deafened, late implanted adults using the Nucleus cochlear implant. RESULTS: Electrode discrimination difference limens across all subjects and electrodes ranged from 0.5 to 7.125, with significantly larger limens for basal electrodes. No significant differences were found between the basic map and the experimental map on auditory tests. Subjective appreciation was found to be significantly poorer for the experimental map. CONCLUSIONS: Prelingually deafened CI users were unable to discriminate between all adjacent electrodes. There was no difference in auditory performance between the basic and experimental map. Potential factors contributing to the absence of improvement with the experimental map include the reduced number of maxima, incomplete adaptation to the new frequency allocation, and the mainly basal location of deactivated electrodes.

Amplitude Modulation Detection and Speech Recognition in Late-Implanted Prelingually and Postlingually Deafened Cochlear Implant Users.

OBJECTIVES: Many late-implanted prelingually deafened cochlear implant (CI) patients struggle to obtain open-set speech understanding. Because it is known that low-frequency temporal-envelope information contains important cues for speech understanding, the goal of this study was to compare the temporal-envelope processing abilities of late-implanted prelingually and postlingually deafened CI users. Furthermore, the possible relation between temporal processing abilities and speech recognition performances was investigated. DESIGN: Amplitude modulation detection thresholds were obtained in eight prelingually and 18 postlingually deafened CI users, by means of a sinusoidally modulated broadband noise carrier, presented through a loudspeaker to the CI user's clinical device. Thresholds were determined with a two-down-one-up three-interval oddity adaptive procedure, at seven modulation frequencies. Phoneme recognition (consonant-nucleus-consonant [CNC]) scores (percentage correct at 65 dB SPL) were gathered for all CI users. For the prelingually deafened group, scores on two additional speech tests were obtained: (1) a closed-set monosyllable-trochee-spondee test (percentage correct scores at 65 dB SPL on word recognition and categorization of the suprasegmental word patterns), and (2) a speech tracking test (number of correctly repeated words per minute) with texts specifically designed for this population. RESULTS: The prelingually deafened CI users had a significantly lower sensitivity to amplitude modulations than the postlingually deafened CI users, and the attenuation rate of their temporal modulation transfer function (TMTF) was greater. None of the prelingually deafened CI users were able to detect modulations at 150 and 200 Hz. High and significant correlations were found between the results on the amplitude modulation detection test and CNC phoneme scores, for the entire group of CI users. In the prelingually deafened group, CNC phoneme scores, word scores on the monosyllable-trochee-spondee test, and speech tracking scores correlated significantly with the mean amplitude modulation detection threshold of the modulation frequencies between 5 and 100 Hz and with almost all separate amplitude modulation thresholds. High correlations with these speech measures were also found for the attenuation rate of and the surface area below the TMTF. In postlingually deafened CI users, CNC phoneme scores only correlated significantly with the 100-Hz and 150-Hz amplitude modulation thresholds, as well as with the attenuation rate of and surface area below the TMTF. CONCLUSIONS: Prelingually deafened CI users were less sensitive to temporal modulations than postlingually deafened CI users, and the attenuation rate of their TMTF was steeper. For all CI users, subjects with better amplitude modulation detection skills tended to score better on measures of speech understanding. Significant correlations with low modulation frequencies were found only for the prelingually deafened CI users and not for the postlingually deafened CI users.

Predictors of spoken language development following pediatric cochlear implantation.

OBJECTIVES: Although deaf children with cochlear implants (CIs) are able to develop good language skills, the large variability in outcomes remains a significant concern. The first aim of this study was to evaluate language skills in children with CIs to establish benchmarks. The second aim was to make an estimation of the optimal age at implantation to provide maximal opportunities for the child to achieve good language skills afterward. The third aim was to gain more insight into the causes of variability to set recommendations for optimizing the rehabilitation process of prelingually deaf children with CIs. DESIGN: Receptive and expressive language development of 288 children who received CIs by age five was analyzed in a retrospective multicenter study. Outcome measures were language quotients (LQs) on the Reynell Developmental Language Scales and Schlichting Expressive Language Test at 1, 2, and 3 years after implantation. Independent predictive variables were nine child-related, environmental, and auditory factors. A series of multiple regression analyses determined the amount of variance in expressive and receptive language outcomes attributable to each predictor when controlling for the other variables. RESULTS: Simple linear regressions with age at first fitting and independent samples t tests demonstrated that children implanted before the age of two performed significantly better on all tests than children who were implanted at an older age. The mean LQ was 0.78 with an SD of 0.18. A child with an LQ lower than 0.60 (= 0.78-0.18) within 3 years after implantation was labeled as a weak performer compared with other deaf children implanted before the age of two. Contralateral stimulation with a second CI or a hearing aid and the absence of additional disabilities were related to better language outcomes. The effect of environmental factors, comprising multilingualism, parental involvement, and communication mode increased over time. Three years after implantation, the total multiple regression model accounted for 52% of the variance in receptive language scores and 58% of the variance in expressive language scores. CONCLUSIONS: On the basis of language test scores of this large group of children, an LQ of 0.60 or lower was considered a risk criterion for problematic language development compared with other deaf children using CIs. Children attaining LQs below 0.60 should be monitored more closely and perhaps their rehabilitation programs should be reconsidered. Improved language outcomes were related to implantation under the age of two, contralateral stimulation, monolingualism, sufficient involvement of the parents, and oral communication by the parents. The presence of an additional learning disability had a negative influence on language development. Understanding these causes of variation can help clinicians and parents to create the best possible circumstances for children with CIs to acquire language.

Quality-of-life benefit from cochlear implantation in the elderly.

OBJECTIVE: To compare the audiologic results of geriatric patients receiving cochlear implants with younger age groups and to evaluate the quality of life after cochlear implantation in the geriatric population by means of validated quality-of-life questionnaires. STUDY DESIGN: Cross-sectional study involving 89 postlingually deafened cochlear implant subjects. SETTING: Tertiary referral center. PATIENTS: A total of 89 postlingually deafened patients were included in the study, among which were 25 patients who were aged 70 years or older. INTERVENTIONS: All patients received a cochlear implant. Subjects were implanted with either the Laura, Nucleus 24, or Med-el Combi 40+ cochlear implant systems implementing the SPEAK, ACE, CIS, or CIS+ coding strategies. MEAN OUTCOME MEASURES: Speech recognition was determined by means of phonetically balanced monosyllabic word lists. The Hearing Handicap Inventory for Adults, the Glasgow Benefit Inventory, and the scale for the prediction of hearing disability in sensorineural hearing loss were used to quantify the quality of life. RESULTS: Mean audiologic performance for the three groups increased significantly after implantation (p < 0.001). Postoperative audiologic performance of the geriatric population led to useful hearing, but these scores were significantly lower than for the younger age groups (p = 0.002). However, the quality-of-life outcomes for the geriatric group were similar to those of the younger age groups (p = 0.411 for the Hearing Handicap Inventory for Adults; p = 0.886 for the Glasgow Benefit Inventory). CONCLUSION: The results of this study prove that cochlear implantation in the elderly provides improvements in quality of life and speech understanding, similar to those for younger adult cochlear implant recipients.

Bilateral cochlear implantation in children.

AIMS: to determine the benefit of bilateral cochlear implantation in a child on speech and language development. METHOD: This child got her first implant, a Nucleus 24-system, on the right side at the age of 2.5 years. The left side was implanted at the age of 4.4 years with a Nucleus 24Contour-system. On the right side she's now wearing an Esprit 24-speechprocessor (SPR). On the left side she has a Sprint-SPR. M. goes to a mainstream school and receives Speech and Language therapy in a Speech and Hearing Rehab Centre. The etiology of her deafness was hyperbilirubinemia. Auditory capacity and speech recognition tests were performed for both ears separately and together. RESULTS: Aided thresholds give a PTA of 28 dBA with the first implant, 22 dBA with the second implant and with both implants we get a PTA of 23 dBA. Results for speech identification and recognition demonstrated an increased performance when both implants are used together. Speech and language development was equivalent to the mean of age 4.5. At the time of testing M. was 4.8 years. At this time the speech and language development show no delays with normal hearing children. CONCLUSIONS: bilateral cochlear implantation in children may have additional value for their speech and language development. Also, implantation may be considered when auditory neuropathy is likely.

Effect of pediatric bilateral cochlear implantation on language development.

OBJECTIVE: To examine spoken language outcomes in children undergoing bilateral cochlear implantation compared with matched peers undergoing unilateral implantation. DESIGN: Case-control, frequency-matched, retrospective cross-sectional multicenter study. SETTING: Two Belgian and 3 Dutch cochlear implantation centers. PARTICIPANTS: Twenty-five children with 1 cochlear implant matched with 25 children with 2 cochlear implants selected from a retrospective sample of 288 children who underwent cochlear implantation before 5 years of age. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURES: Performance on measures of spoken language comprehension and expression (Reynell Developmental Language Scales and Schlichting Expressive Language Test). RESULTS: On the receptive language tests (mean difference [95% CI], 9.4 [0.3-18.6]) and expressive language tests (15.7 [5.9-25.4] and 9.7 [1.5-17.9]), children undergoing bilateral implantation performed significantly better than those undergoing unilateral implantation. Because the 2 groups were matched with great care on 10 auditory, child, and environmental factors, the difference in performance can be mainly attributed to the bilateral implantation. A shorter interval between both implantations was related to higher standard scores. Children undergoing 2 simultaneous cochlear implantations performed better on the expressive Word Development Test than did children undergoing 2 sequential cochlear implantations. CONCLUSIONS: The use of bilateral cochlear implants is associated with better spoken language learning. The interval between the first and second implantation correlates negatively with language scores. On expressive language development, we find an advantage for simultaneous compared with sequential implantation.