J.P.L. Brokx

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.

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.

The relation between age at the time of cochlear implantation and long-term speech perception abilities in congenitally deaf subjects

The issue of whether an upper age limit should be set for cochlear implantation in congenitally deaf subjects has often been debated. To gain more insight, the speech perception abilities were analyzed of 12 congenitally deaf subjects whose age at the time of cochlear implantation ranged from 4 to 33 years. Subjects implanted during adulthood only showed progress during the first few months after the speech processor had been fitted and their long-term results were poor compared to those of children implanted early in life. This latter group showed steady improvement over the whole evaluation period. The present results support the notion that the earlier in life implantation is performed, the better the development of speech perception. Based on the progress-over-time profiles and data on actual daily use of the cochlear implant, it can be suggested that implantation of congenitally deaf subjects during or after puberty offers only limited benefit.

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.

The ASSR: clinical application in normal-hearing and hearing-impaired infants and adults, comparison with the click-evoked ABR and pure-tone audiometry

The objective of this study was to investigate the clinical application of the ASSR (GSI Audera). It was completed in two parts: Study 1. Correlation between the ASSR-based threshold estimations and the conventional pure-tone thresholds in adults; and Study 2. Correlation between the average of the 2–4 kHz ASSR-based threshold estimations and c-ABR thresholds in children.The ASSRs were recorded in awake adults and sleeping infants with a range of hearing loss at CFs of 0.5 to 4 kHz and MFs between 46 and 95 Hz. The results show that in hearing-impaired adults (thresholds > 40 dBHL) good correlations can be observed between the behavioural thresholds and the ASSR-based threshold estimations. For the normal- to near-normal-hearing adults, a significant correspondence exists between the ASSR-based threshold estimations and FPTA. In children, strong correlations were found between the c-ABR and the 2–4 kHz ASSR-based threshold estimation average. These studies illustrate that the GSI Audera ASSR can accurately predict the behavioural audiogram in hearing-impaired subjects. In subjects with normal hearing the individual ASSR-based threshold estimations scatter too much. Instead the average of the ASSR-based threshold estimations corresponds well with the FPTA.

The risk of vestibular function loss after intracochlear implantation

Sixty patients were selected for cochlear implantation and 50 of them received an intracochlear implant (Nucleus). Vestibular function was evaluated before and after surgery using a caloric test and a velocity step test. Sixteen patients had normal or residual vestibular function before surgery, 11 bilateral and 5 unilateral; in 3 of the latter patients, the ear with vestibular areflexia was elected for implantation, which reduced the number of patients at risk for vestibular dysfunction to 13. Vestibular function was preserved in all of these patients except for 4; the risk of vestibular function loss can therefore be rated at about 31%.

Sensitivity to Interaural Level Difference and Loudness Growth with Bilateral Bimodal Stimulation

The interaural level difference (ILD) is an important cue for the localization of sound sources. The sensitivity to ILD was measured in 10 users of a cochlear implant (CI) in one ear and a hearing aid (HA) in the other severely impaired ear. For simultaneous presentation of a pulse train on the CI side and a sinusoid on the HA side the just noticeable difference (JND) in ILD and loudness growth functions were measured. The mean JND for pitch-matched electric and acoustic stimulation was 1.7 dB. A linear fit of the loudness growth functions on a decibel-versus-microampere scale shows that the slope depends on the subject’s dynamic ranges.

Good speech recognition and quality-of-life scores after cochlear implantation in patients with DFNA9.

Objective: To compare audiometric and quality-of-life results in DFNA9 patients who received a cochlear implant with cochlear implant patients with adult-onset progressive sensorineural hearing loss. Study Design: Prospective comparative design; results were collected cross-sectionally. Setting: Tertiary referral center. Patients: Eleven DFNA9 patients were included in the study as well as a comparative group of 39 postlingually deafened cochlear implant subjects with adult-onset progressive sensorineural hearing loss. Interventions: All patients received a cochlear implant. Subjects were implanted with either the Nucleus 24M/RCS or Med-el Combi 40+ cochlear implant systems implementing the SPEAK, ACE, 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: The results show that the speech perception and the quality of life of the DFNA9 patients do not differ significantly from the control group (p = 0.179; p = 0.56). Conclusion: In spite of the fact that DFNA9 is a disease that is known to involve cochlear dendrites, cochlear implantation is a good option for treatment of deafness in DFNA9.

Hearing-aid fitting in profoundly hearing-impaired children. Comparison of prescription rules

Generally, the performance of a hearing-impaired child with his or her hearing aids is the major criterion in selection programmes for cochlear implantation. Thereto, it has to be considered whether the hearing-aid fitting is optimal. For this purpose, methods which prescribe hearing-aid gain are valuable, especially in young preverbal children. Three of these methods were evaluated by comparing the calculated and measured gain as a function of frequency in a selected group of profoundly hearing-impaired children (n = 16), all of whom were successful users of hearing aids. Fair agreement was found for the modified NAL rule applicable in profoundly hearing-impaired subjects and the DSL method (desired sensation level method).

Oral language acquisition in children assessed with the Reynell Developmental Language Scales.

Oral language development of ten children, prelingually deafened by meningitis, was assessed with a Dutch version of the Reynell Developmental Language Scales. The test was administered pre-operatively and at regular intervals after implantation. The average rate of language development between two consecutive evaluations was computed. This rate was defined as the quotient of the increase of the language age and the increase of the chronological age between the evaluations. A normal language development has a rate of 1; this means 12 months language development in 12 months time. In case of language retardation the rate of language development is less than 1. The rate of receptive language development showed a gradual increase. In the interval between 12 and 24 months of implant use the ratio was 0.9. This implies a language development that is quite similar with the development in normal hearing children. The rate of expressive language development showed a fast improvement in the period between 6 and 12 months after implantation, up to 1.4. If this rate of development continues the children with C.I. will catch up with their normal hearing peers.