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Updated: Jun 13, 2026
Cochlear Implant Surgery and Electrically-evoked Auditory Brainstem Response Recordings in C57BL/6 Mice
Published on: January 9, 2019
Electrically evoked auditory brainstem responses in children with sequential bilateral cochlear implants
Marloes Sparreboom1, Andy J Beynon, Ad F M Snik
1Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen, The Netherlands. m.sparreboom@kno.umcn.nl
Insights
Sequential bilateral cochlear implantation (CI) shows auditory brainstem maturation, but the second implant (CI2) side may lag behind the first (CI1). Age at CI2 does not significantly impact latency differences over time.
Area of Science:
- Neuroscience
- Audiology
- Pediatric Medicine
Background:
- Sequential bilateral cochlear implantation (CI) is a common treatment for prelingual deafness.
- Understanding auditory brainstem maturation after CI is crucial for optimizing auditory development.
- The impact of the age at second CI (CI2) on brainstem maturation remains an area of investigation.
Purpose of the Study:
- To investigate the effect of sequential bilateral cochlear implantation on auditory brainstem maturation.
- To determine the influence of the age at receiving the second cochlear implant (CI2) on auditory brainstem development.
Main Methods:
- A prospective cohort study was conducted at a tertiary academic referral center.
- Thirty prelingually deaf children received sequential bilateral cochlear implantation (CI1 at 1.8 years, CI2 at 5.3 years).
- Electrically evoked auditory brainstem responses (eABRs) were measured intraoperatively and at 6, 12, and 24 months postoperatively.
Main Results:
- Wave V latency was initially prolonged on the CI2 side compared to CI1, but this difference became non-significant after 12-24 months.
- Interwave interval III-V latencies remained significantly prolonged on the CI2 side.
- Age at CI2 did not correlate with individual latency differences across all measured waveforms.
Conclusions:
- Auditory brainstem maturation occurs after sequential bilateral cochlear implantation, even after a period of unilateral deafness.
- The CI2 side shows some persistent abnormalities compared to the CI1 side, suggesting incomplete catch-up.
- While interaural latencies decrease over time, longer follow-up may reveal full maturation of the CI2 side.
Objective:
To examine the effect of sequential bilateral cochlear implantation on auditory brainstem maturation and the effect of age in receiving the second implant (CI2).
Study Design:
Prospective cohort study.
Setting:
Tertiary academic referral center.
Patients:
Thirty prelingually deaf children, who received their first implant (CI1) at a mean age of 1.8 year and their CI2 at a mean age of 5.3 years.
Intervention:
Sequential bilateral cochlear implantation.
Main Outcome Measure:
Electrically evoked auditory brainstem responses on the 2 implant sides were measured intraoperatively and postoperatively after 6, 12, and 24 months of bilateral implant use.
Results:
Electrically evoked auditory brainstem response latencies on the 2 implants were compared within subjects over time. Wave III did not show any significant differences between the 2 sides, whereas Wave V was initially prolonged on the CI2 side compared with the CI1 side. Although still apparent, this interaural latency difference of Wave V was no longer significant after 12 and 24 months. Interwave interval III to V latencies remained significantly prolonged on the CI2 side. Age in receiving the CI2 did not account for the individual differences in latencies for all waveforms.
Conclusion:
The present data suggest that auditory brainstem maturation will occur after a relatively long period of unilateral deafness irrespective of the age in receiving the CI2. Because some abnormalities were still seen at the upper part of the brainstem, our results indicate that the CI2 side has not caught up with the CI1 side. Nevertheless, within our follow-up time, interaural (interwave) latencies decrease significantly, and longer-term data might reveal that the CI2 eventually will catch up with the CI1 side.
