From Bimodal Hearing to Sequential Bilateral Cochlear Implantation in Children-A Within-Subject Comparison.

Objective: To evaluate the performance changes after sequential bilateral cochlear implantation in a pediatric population of bimodal cochlear implant (CI) users. To evaluate the factors which influence the parental and recipient decision to discontinue hearing aid use and seek a second implant.

Study Design: Retrospective case review, within-subject comparison.

Setting: Tertiary referral center.

Patients: Thirty-one pediatric (<18 yr) bimodal CI users who underwent sequential bilateral CI.

Interventions: Sequential bilateral CI.

Main Outcome Measures: Parental and/or recipient's reasons for discontinuing their hearing aid and pursuing a second implant, device usage from datalogs, speech understanding in the bimodal and bilateral CI condition.

Results: Parents/patients were motivated to pursue sequential bilateral CI based on their positive performance with CI1, the expectation of further improvement with a second CI, and the prospect of having a second independently functional ear. In the bimodal condition, mean word recognition score (WRS), sentence recognition in quiet (SIQ), and sentence recognition in noise (SIN) scores were 87.4, 97.3, and 92.9% respectively. At 1-year post-sequential bilateral CI, the mean WRS, SIQ, and SIN score were 92.7, 98.7, and 97.7%, respectively. The improvement in bilateral CI speech scores compared with bimodal scores was statistically significant for WRS (p = 0.015). A ceiling effect limited the ability to detect further meaningful differences on speech perception testing.

Conclusions: The bilateral CI condition demonstrates equivalent or slightly superior performance compared with the bimodal condition. Several non-speech benefits were elicited from parents as reasons for pursuing a second implant. Close monitoring of the residual acoustic hearing, inquiring about the perceived benefits provided by the HA, and early counseling regarding the potential for sequential bilateral CI are important aspects in determining if and when a second implant is indicated.