Long-term outcomes and electrophysiological measures of children with inner ear malformations and cochlear implants

Objectives: To compared auditory and speech performance outcomes of children with cochlear implants (CI), between those with inner ear malformations (IEMs) and with normal ear anatomy; and to describe differences in electrophysiological measurements. Study design: A retrospective study. Setting: A tertiary care pediatric medical center. Patients: Forty-one children with IEMs who underwent CI during 2003–2017, and 41 age-matched CI recipients with normal ear anatomy (control group). Main outcome measures: Post-CI auditory performance outcomes including educational setting, Categories of Auditory Performance (CAP), and Speech Intelligibility Rating (SIR); and electrophysiological measurements, Including maximal comfortable electrical levels (CLs) and impedances along CI electrodes. Results: The ANOVA on ranks revealed lower CAP scores in the study than control group: H3 = 18.8, P < 0.001. Among children with IEMs, CAP scores were better in children with enlarged vestibular aqueduct (EVA) (P < 0.04). SIR scores of the control group did not differ from those with isolated EVA; however, SIR scores of the IEMs without EVA subgroup were lower than all the other study subgroups (P < 0.01). The proportion of the control group that was integrated with full inclusion educational settings into the regular mainstream schools was higher than for those with IEMs without EVA (47 % vs. 15 %, P < 0.05), but similar to those with isolated EVA. For the study group versus control group, maximal comfortable electrical levels (CLs) were higher)P > 0.03) while impedance measurements were similar. Conclusions: Outcomes of pediatric recipients with normal anatomy were better than those with IEMs. Among pediatric recipients of CI with IEMs, auditory performance was better and CLs were lower among children with isolated EVA than all other IEM subgroups.