Sequential bilateral implantation in older children: Inter‐implant map differences and their effects on functional outcomes

Long-term effects of second cochlear implantation with sequential bilateral cochlear implantation in Japanese children

OBJECTIVE

This study aimed to longitudinally evaluate speech perception ability and sound-field thresholds with the first, second, or bilateral cochlear implants (CIs) and MAP parameters of second CI in children.

METHODS

Eighteen children who underwent bilateral cochlear implantation at Kyoto University Hospital were included. We evaluated speech perception under quiet and noisy conditions using the first, second, or bilateral CIs, CI-aided sound-field thresholds using the first or second CI, and MAP parameter values (C-levels, T-levels, and dynamic range) of the second CI of more than 5 years after the second implantation.

RESULTS

Patients with a second CI after 7 years of age had significantly worse speech perception ability with the second CI even long after the surgery than those with a second CI before 7 years of age. CI-aided sound-field thresholds using the first or second CI were similar, regardless of the second implantation timing. Speech perception in noise with bilateral CIs was enhanced by the addition of a second CI, even after 7 years of age. Patients undergoing second cochlear implantation before 3.5 years of age showed significantly higher C-levels and wider dynamic ranges in the second CI MAP parameters.

CONCLUSIONS

When the second implantation was performed after 7 years of age, the second CI effects were limited even with long-term use, which is attributed to unstable MAP parameters. The second CI-aided sound-field threshold contributed to the better outcome of bilateral CIs in noise, even if the second implantation was performed at age of ≥7 years.

New approach in programming sequentially implanted children: Towards balanced dynamic ranges (DR)

There is a tendency for children undergoing sequential cochlear implant after a long period of unilateral implant use to have a smaller dynamic range in their second implant compared to their first implant. This study aimed to investigate if balancing the dynamic ranges between the two implants influenced functional outcomes in sequentially implanted children. Nineteen participants with long inter-implant time delays were randomly assigned to a study group or a control group. Children in the study group received progressive minimal changes to both first and second implants over a period of nine months to achieve balanced dynamic ranges, while the children in the control group received only changes to their sequential implant. Functional outcomes were collected 24-months after sequential implantation and consisted of speech discrimination scores, spatial localisation, device use and quality of life measures. Results show that spatial discrimination skills improved over time for both groups of children; however children in the study group had smaller localisation errors compared with the children in the control group. No other differences between the two groups were observed. Balanced dynamic ranges in sequentially implanted children can contribute to better performance, particularly in spatial discrimination tasks that rely in inter-aural level differences.

Enhancement of interaural level differences for bilateral cochlear implant users

Bilateral cochlear implant (BiCI) users do not localize sounds as well as normal hearing (NH) listeners do. NH listeners rely on two binaural cues to localize sounds in the horizontal plane, namely interaural level differences (ILDs) and interaural time differences. BiCI systems, however, convey these cues poorly. In this work, we investigated two methods to improve the coding of ILDs in BiCIs. The first method enhances ILDs by applying an artificial current-versus-angle function to the clinical levels delivered by the basal electrodes of the CI contralateral to the target sound. The second method enhances ILDs by using bilaterally linked N-of-M band selection. Results indicate that the participants were able to discriminate the location of the sound more accurately at narrow azimuths when the ILD enhancement was applied, compared to when they were using natural ILDs. Also, the results show that linking the band selection had a positive effect on left/right discrimination accuracy at larger azimuths for three out of the 10 tested participants, when compared to unlinked band selection. Based on these results, we conclude that ILD enhancement besides linked N-of-M band selection can help some BiCI participants to discriminate sound sources on the frontal horizontal plane.

Bilateral Cochlear Implantation in Children: Long-Term Outcome in the Adult Population With Special Emphasis on the Bilateral Benefit

OBJECTIVE

To investigate the benefit of bilateral cochlear implantation in adults, who had been implanted being a child under the age of 10 years.

STUDY DESIGN

Retrospective data analysis.

SETTING

Tertiary referral center with a large cochlear implant program.

MAIN OUTCOME MEASURES

Speech understanding in the Freiburg monosyllabic words in quiet and the HSM sentence test in quiet and in background noise.

PATIENTS

Seventy-seven bilaterally cochlear implantation implanted adults.

RESULTS

Bilateral cochlear implantation in children under the age of 10 years results in a significant benefit in speech comprehension in adulthood. In addition, a dependency regarding the time between the implantations and speech intelligibility was found.

CONCLUSION

The results emphasize the benefit of bilateral cochlear implantation with a short interval between the operations in young children not only during formative years but also in adulthood.

The Clinical Effects of Steroids Therapy in the Preserving Residual Hearing after Cochlear Implantation with the OTICON Neuro Zti EVO

Background: A prospective clinical study was conducted to investigate whether two different pharmacotherapy strategies of steroid administration impact hearing preservation in adult patients who underwent cochlear implantation with the Oticon Medical Neuro cochlear implant system. Methods: Twenty nine adult participants were included. Pure tone audiometry was performed before implantation, during processor activation and 12 months after activation. There were three treatment groups: (1) intravenous steroid therapy (standard steroid therapy with dexamethasone administrated intravenously at the dose 0.1 mg/kg body mass twice a day); (2) combined oral and intravenous steroid therapy (extended steroid therapy with dexamethasone administrated intravenously at the dose 0.1 mg/kg b.m. twice a day and prednisone (orally) at the dose 1 mg/kg body mass/24 h), and (3) no steroid therapy (a control group). Patients’ hearing thresholds before implantation were on average 103 dB HL, 89 dB HL, and 93 dB HL, respectively. Results: Deterioration of hearing thresholds was observed in all three patients’ groups. Twelve months after surgery the patients with and without steroid therapy had similar hearing thresholds. Conclusions: The steroid regimen used in this study did not play a significant role in patients with non-functional residual hearing, who underwent cochlear implantation with the Oticon Medical Neuro cochlear implant system.

A retrospective review of parents' perceptions of the impact of bilateral cochlear implants on their child's quality of life

OBJECTIVE

To evaluate the impact of simultaneous and sequential bilateral cochlear implantation on deaf children's quality of life (QoL) and to investigate the impact of inter-implant time delay for the sequentially implanted children.

METHODS

All completed questionnaires of the Brief Assessment of Parental Perception (BAPP), which had been routinely filled out by parents at annual review, were analysed for children with at least 12 months of bilateral implant experience. The responses for the simultaneous implanted group were compared to those who received sequential implants. Within the sequential group, the impact of shorter (<7 years) and longer (>7 years) inter-implant delays on QoL were compared.

RESULTS

There were a total of 176 children in the sequential group and 97 in the simultaneous group. Results indicated that most children wore their devices regularly and significant improvements in QoL were reported for all children particularly in communication and learning. QoL scores were higher for the children with simultaneous implants, followed by children with a shorter time delay between implants.

CONCLUSION

Both simultaneous and sequential bilateral cochlear implants significantly improved the functioning and QoL of deaf children.