Inter-implant Interval Research Articles

Sequential Bilateral Cochlear Implantation in Children: Outcome of the Second Implant and Long-Term Use.

The aim of this retrospective cohort study was to assess speech perception outcomes of second-side cochlear implants (CI2) relative to first-side implants (CI1) in 160 participants who received their CI1 as a child. The predictive factors of CI2 speech perception outcomes were investigated. In addition, CI2 device use predictive models were assessed using the categorical variable of participant's decision to use CI2 for a minimum of 5 years after surgery. Findings from a prospective study that evaluated the bilateral benefit for speech recognition in noise in a participant subgroup (n = 29) are also presented. Participants received CI2 between 2003 and 2009 (and CI1 between 1988 and 2008), and were observed from surgery to a minimum of 5 years after sequential surgery. Group A (n = 110) comprised prelingually deaf children (severe to profound) with no or little acquired oral language before implantation, while group B (n = 50) comprised prelingually deaf children with acquired language before implantation, in addition to perilingually and postlingually deaf children. Speech perception outcomes included the monosyllable test score or the closed-set Early Speech Perception test score if the monosyllable test was too difficult. To evaluate bilateral benefit for speech recognition in noise, participants were tested with the Hearing in Noise test in bilateral and "best CI" test conditions with noise from the front and noise from either side. Bilateral advantage was calculated by subtracting the Hearing in Noise test speech reception thresholds in noise obtained in the bilateral listening mode from those obtained in the unilateral "best CI" mode. On average, CI1 speech perception was 28% better than CI2 performance in group A, the same difference was 20% in group B. A small bilateral speech perception benefit of using CI2 was measured, 3% in group A and 7% in group B. Longer interimplant interval predicted poorer CI2 speech perception in group A, but only for those who did not use a hearing aid in the interimplant interval in group B. At least 5 years after surgery, 25% of group A and 10% of group B did not use CI2. In group A, prediction factors for nonuse of CI2 were longer interimplant intervals or CI2 age. Large difference in speech perception between the two sides was a predictor for CI2 nonuse in both groups. Bilateral advantage for speech recognition in noise was mainly obtained for the condition with noise near the "best CI"; the addition of a second CI offered a new head shadow benefit. A small mean disadvantage was measured when the noise was located opposite to the "best CI." However, the latter was not significant. Generally, in both groups, if CI2 did not become comparable with CI1, participants were more likely to choose not to use CI2 after some time. In group A, increased interimplant intervals predicted poorer CI2 speech perception results and increased the risk of not using CI2 at a later date. Bilateral benefit was mainly obtained when noise was opposite to CI2, introducing a new head shadow benefit.

Speech recognition in bilaterally cochlear implanted adults in Tokyo, Japan

Introduction: The clinical effects of bilateral cochlear implantation (BCI) include binaural summation and better hearing under noise conditions. This study retrospectively examined the utility of BCI compared to unilateral cochlear implantation (CI) in adults.Patients and methods: We investigated 34 adults who underwent BCI, comparing speech recognition between BCI and first CI under silent and noise conditions. We assessed correlations between speech recognition after first and second CIs, and between the interval from first to second CI surgery and speech recognition of second CI.Results: Word recognition score (WRS) and sentence recognition score (SRS) were significantly better after BCI than after first CI under conditions of silence and noise. No significant correlation was found between speech recognition after first CI and that after second CI, or between inter-implant interval and speech recognition of second CI for either WRS or SRS.Conclusions: The utility of BCI in Japanese patients was shown. Patients have no need to be pessimistic about hearing after the second implantation even if speech recognition after the first implantation is poor. A long interval from first CI does not necessarily contraindicate contralateral implantation in adults.

United Kingdom national paediatric bilateral project: Demographics and results of localization and speech perception testing

Objectives: To assess longitudinal outcomes in a large and varied population of children receiving bilateral cochlear implants both simultaneously and sequentially.Methods: This observational non-randomized service evaluation collected localization and speech recognition in noise data from simultaneously and sequentially implanted children at four time points: before bilateral cochlear implants or before the sequential implant, 1 year, 2 years, and 3 years after bilateral implants. No inclusion criteria were applied, so children with additional difficulties, cochleovestibular anomalies, varying educational placements, 23 different home languages, a full range of outcomes and varying device use were included.Results: 1001 children were included: 465 implanted simultaneously and 536 sequentially, representing just over 50% of children receiving bilateral implants in the UK in this period. In simultaneously implanted children the median age at implant was 2.1 years; 7% were implanted at less than 1 year of age. In sequentially implanted children the interval between implants ranged from 0.1 to 14.5 years. Children with simultaneous bilateral implants localized better than those with one implant. On average children receiving a second (sequential) cochlear implant showed improvement in localization and listening in background noise after 1 year of bilateral listening. The interval between sequential implants had no effect on localization improvement although a smaller interval gave more improvement in speech recognition in noise. Children with sequential implants on average were able to use their second device to obtain spatial release from masking after 2 years of bilateral listening. Although ranges were large, bilateral cochlear implants on average offered an improvement in localization and speech perception in noise over unilateral implants.Conclusion: These data represent the diverse population of children with bilateral cochlear implants in the UK from 2010 to 2012. Predictions of outcomes for individual patients are not possible from these data. However, there are no indications to preclude children with long inter-implant interval having the chance of a second cochlear implant.

Sequential bilateral cochlear implantation in the adolescent population.

To examine the variables affecting outcomes for sequential bilateral cochlear implantation patients in the adolescent population. Retrospective chart review at tertiary care center. Main outcome measures were open set speech recognition tests at the word (Consonant-Nucleus-Consonant/Phonetically Balanced Kindergarten List Test [CNC/PBK]) and sentence levels in noise (Hearing in Noise Test-Noise [HINT-N]) in different test conditions with respect to the age at first and sequential implantation, as well as the interval between implants. Despite a mean age at sequential implantation of 13.5 years, sequential bilateral implanted adolescents revealed significant improvement in the sequential cochlear implant (CI2) ear. The mean time interval between implants was 8.2 years. A wide range of performance was noted, and age at implantation and interval between first cochlear implant (CI1) and CI2 did not predict outcome. Mean CNC/PBK score with CI1 alone was 83.0%, with the CI2 alone was 56.5%, and with bilateral implants was 86.8%. Sentence scores (HINT-N) were 89.5% for CI1, 74.2% for CI2, and 94.4% for bilateral CI condition. The clinical relevance of these enhanced perception abilities requires attention to individual device use, performance with the first implant, and subjective benefits reported by patients. Bilateral sequential cochlear implantation leads to improved speech perception in the adolescent population and should be considered in this population, even after a long period of deafness and despite a prolonged interval between implants. Numerous factors affect the ability to predict performance, but age at implantation and interimplant interval were not correlated with performance measures. Extensive preoperative counseling and individualized evaluation are critical to ensure that patients and families understand the range of possible outcomes. 4

Functional Listening Performance of Children with Sequential Bilateral Cochlear Implantation in Daily Life

Received November 13, 2014 Revised December 22, 2014 Accepted January 2, 2015 Address for correspondence Yun-Hoon Choung, MD, DDS, PhD Department of Otolaryngology, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon 443-380, Korea Tel +82-31-219-5263 Fax +82-31-219-5264 E-mail yhc@ajou.ac.kr Background and ObjectivesZZThis study aims to identify whether the sequential bilateral cochlear implantation in children with a long inter-implant interval provides functional benefits in everyday situation. Subjects and MethodZZSeventeen children with sequential bilateral cochlear implants (BiCIs) (mean age at first implantation, 2.6 years; mean age at second implantation, 8.5 years; mean inter-implant interval, 6.0 years) and 17 children with unilateral cochlear implants (UniCIs) were included in this study. The questionnaire SSQ (The Speech, Spatial, and Qualities of hearing scale for parents of children with impaired hearing, Galvin, 2007) was used to evaluate the performance of two groups by individually interviewing the parents of the subjects. For the BiCIs, anecdotal reports of the performance in everyday listening situation and device use were also collected in interviews. ResultsZZThe BiCI group showed significantly better performance in all three areas (speech perception, spatial hearing, and other qualities of hearing) of the SSQ than did the UniCI group. The differences between the two groups were significantly larger in performance on ‘spatial hearing’ and ‘other qualities of hearing’ than on ‘speech perception’. All subjects with bilateral cochlear implants had a positive attitude on bilateral hearing. Anecdotal reports indicated that bilateral hearing has positive effects such as reduced repeated questions, increased participation in conversation, facilitated language and learning acquisition, and improved concentration. ConclusionZZChildren who received sequential bilateral cochlear implantation with a long inter-implant interval could obtain functional benefits in daily life. Also it turned out that these benefits have positive effects on children’s communication, language, learning, and socio-emotional areas. Korean J Otorhinolaryngol-Head Neck Surg 2015;58(7):463-8

Effects of the Inter-Implant Interval and Listening Condition on Speech Perception in Children with Sequential Bilateral Cochlear Implants

배경 및 목적: 본 연구에서는 집단(양측 인공와우이식 간격이 짧은 아동, 양측 인공와우 간격이 긴 아동, 일측인공와우 아동)과 듣기 조건(조용한 조건, 소음 조건)에 따른 말지각을 살펴보았다. 그리고 양측 인공와우 아동의 첫 번째와 두 번째 인공와우이식 연령, 인공와우이식 간격, 양측 인공와우 착용 기간이 소음 조건에서의 말지각에 유의한 영향을 미치는지...

Bilateral cochlear implantation in children and the impact of the inter‐implant interval

To determine the effectiveness of simultaneous versus sequential bilateral cochlear implantation on postoperative outcomes in children with bilateral deafness and to evaluate the impact of the inter-implant interval and age at second implantation on postoperative outcomes in children who already received their first cochlear implant. PubMed, Embase, and Web of Science. All studies comparing the effects of simultaneous with sequential bilateral cochlear implantation on postoperative outcomes and those evaluating the impact of the inter-implant interval and age at second implantation were retrieved. Four studies compared the effects of simultaneous with sequential bilateral cochlear implantation. All studies lacked randomization. Of these, three reported better speech perception and expressive language development at one year of bilateral experience for simultaneous cochlear implantation. Of the nineteen publications on the impact of the inter-implant interval on postoperative outcomes, the risk of bias was low-moderate for seven studies which were derived from five different study populations. In two of these populations no impact of the inter-implant interval was found, while in three a longer inter-implant interval was associated with poorer speech and language development. Observational studies suggest that simultaneous implantation in children may be associated with improved speech and language development, and that a prolonged inter-implant interval between both implantations may have a negative impact on these postoperative outcomes. Randomized trials are, however, needed to demonstrate whether simultaneous implantation indeed is superior to sequential bilateral implantation in children with bilateral deafness. NA.

Speech Comprehension in Children and Adolescents After Sequential Bilateral Cochlear Implantation With Long Interimplant Interval

Identify likely predictors for the outcome after contralateral cochlear implantation with a long interimplant delay. Retrospective case reviews. Outpatient cochlear implant (CI) center. Seventy-three children and adolescents who underwent sequential bilateral cochlear implantation with an interval between both implantations of 5 years or longer. The mean age of the patients at the first and second cochlear implantations was 2.72 ± 1.52 and 11.57 ± 2.9 years, respectively. The mean duration of experience with both implants was 4.01 ± 1.57 years. Rehabilitative. All 73 patients underwent periodic speech perception testing in quiet and noise. The most recent unilateral data for each side were statistically analyzed. The speech test results were evaluated by the age at first implantation, the interval between both implantations, the duration of hearing aid use in the second side, and the duration of the bilateral CI use. A statistically significant difference for speech test results was obtained between the early-implanted ears and the late-implanted ears for all children. These results were dependent on the interimplant interval. All age groups demonstrated significant differences (p > 0.05) for the second side between the speech test results and the interval between both cochlear implantations. In addition, statistically significant differences influenced by the duration of hearing aid use were found for speech test results for the second side. Experience was also a factor for the second CI, yielding significantly higher speech test scores with longer use. The development of hearing abilities in a second-implanted side depends on the interimplant interval, the hearing aid use, and the duration of the second CI use.

Sound localising ability in children with bilateral sequential cochlear implants

ObjectivesTo evaluate the sound localisation ability in children with sequential bilateral cochlear implants and the potential influence of age at the time of the first implantation, years of experience with the first implanted ear and the inter-implant interval (time between the first and the second cochlear implantation). MethodsSixty-three prelingually deaf children (mean age, 11.03; range, 6.5–17 years; SD, 3.09) were tested after 12 and 24 months of using bilateral cochlear implants. Every child was tested with each ear alone and both ears together. Five loudspeakers were placed in a 180° horizontal arch with 45° of separation between each loudspeaker. The child was placed 1.5m from the speakers. For each test run, three stimuli were presented at 65dB (A) from each speaker for a total of 15 stimulus presentations. For each test run, we calculated the mean angular error (MAE) and the proportion of correct speakers identified (CSS: correct speaker score). Performance by chance for the MAE was 72° and for the CSS was 20% (1 of 5 speakers). ResultsAfter 12 months of using bilateral CIs, the added effect of the second CI in the MAE was minor, and there was no significant difference in CSS between listening in the unilateral condition and listening in bilateral condition. After 24 months, however, the added effect of the second CI in the MAE was significant (mean diff=12.2°; 95% CI; 4.5–20.0°, p=0.003). The mean bilateral CSS increased significantly to 38% (diff=7.7%; 95% CI; 1.4–14.0%; p=0.019) while the mean unilateral CSS remained at a similar level (27%). The influence of age at the time of the first implantation on CSS after 24 months was not significant (p=0.96). However, the inter-implant interval showed a significant decrease in score by 1.4% per year between the two implants (p=0.04). ConclusionSound localisation with two versus one CI in children with a sequential bilateral cochlear implantation was significantly improved 24 months (but not 12 months) after the second implantation. A shorter inter-implant interval showed a small but significant beneficial effect on sound localisation.

Comparison of bilateral and unilateral cochlear implants in children with sequential surgery

Objective The objective of this study was to evaluate the effect of bilateral versus unilateral cochlear implants and the importance of the inter-implant interval. Methods Seventy-three prelingually deaf children received sequential bilateral cochlear implants. Speech recognition in quiet with the first, second and with both implants simultaneously was evaluated at the time of the second implantation and after 12 and 24 months. Results Mean bilateral speech recognition 12 and 24 months after the second implantation was significantly higher than that obtained with either the first or the second implant. The addition of a second implant was demonstrated to have a beneficial effect after both 12 and 24 months. Speech recognition with the second implant increased significantly during the first year. A small, non-significant improvement was observed during the second year. The inter-implant interval significantly influenced speech recognition with the second cochlear implant both at 12 and 24 months, and bilateral speech recognition at 12 months, but not at 24 months. Conclusions A small, but statistically significant improvement in speech recognition was found with bilateral cochlear implants compared with a unilateral implant. A major increase in speech recognition occurred with the second cochlear implant during the first year. A shorter time interval between the two implantations resulted in better speech recognition with the second implant. However, no definitive time-point was found for when the second implant could no longer add a positive effect.

Horizontal Sound Localization in Children With Bilateral Cochlear Implants

To study sound localization performance in relation to auditory experience and age at implantation in children with bilateral cochlear implants. Clinical study. University hospital. Sixty-two sequentially and 4 simultaneously bilaterally implanted children participated in this clinical sound localization study, at a median age of 5.6 years. They underwent sequential implantations at median ages of 1.9 and 4.2 years, respectively. Simultaneous implantations were performed at a median age of 2.0 years. Localization performance was measured with pink noise presented in random order from 5 loudspeakers in the frontal horizontal plane. Twenty-one subjects participated in repeated testing. Sound localization performance as quantified with an Error Index. On group level, bilaterally implanted children pinpointed the sounding loudspeaker in the frontal horizontal plane. Sound localization performance improved significantly with increasing bilateral cochlear implant experience, as observed in the entire study group and intraindividually, albeit large interindividual variability existed. Regression analyses in the entire study group and in the sequentially implanted children did not reveal any relationship between sound localization performance and ages at first and second implantation, interimplant interval, or age. However, second implantation before 4 years of age contributed to faster sound localization improvement with increasing bilateral cochlear implant experience. Median perceived azimuths coincided with presented azimuths. We suggest that listening experience after bilateral cochlear implantation affects sound localization performance, possibly owing to the ongoing stimulus-driven maturation of the central auditory system. The amount of time listening with bilateral implants has methodologic implications on sound localization assessment in bilaterally implanted children.

The benefits of sequential bilateral cochlear implantation for hearing-impaired children

Conclusion. Sequential bilateral implantation offers listening advantages demonstrable on speech recognition in noise and for lateralization. Whilst the trend was for shorter inter-implant intervals and longer implant experience to positively impact binaural advantage, we observed no contraindications for binaural advantage. Objective. To evaluate the benefits of sequential bilateral cochlear implantation over unilateral implantation in a multicentre study evaluating speech recognition in noise and lateralization of sound. Subjects and methods. Twenty children, implanted bilaterally in sequential procedures, had the following characteristics: they were native German-speaking, were3 years or older and had a minimum of 1 year inter-implant interval and had between 2 months and 4 years 7 months binaural listening experience. Binaural advantage was assessed including speech recognition in noise using the Regensburg modification of the Oldenburger Kinder-Reimtest (OLKI) and lateralization of broadband stimuli from three speakers. Results. A significant binaural advantage of 37% was observed for speech recognition in noise. Binaural lateralization ability was statistically superior for the first and second implanted ear (p=0.009, p=0.001, respectively). Binaural experience was shown to correlate moderately with absolute binaural speech recognition scores, with binaural advantage for speech recognition and with binaural lateralization ability. The time interval between implants correlated in an inverse direction with binaural advantage for speech recognition.