Etiology and therapy indication for cochlear implantation in children with single-sided deafness : Retrospective analysis.

OBJECTIVE: The characteristics of children with single-sided deafness (SSD) who become candidates for unilateral cochlear implantation (uCI) were identified. STUDY DESIGN: In all, 118 children with SSD presenting from 2013-2019 to a tertiary pediatric children's hospital were retrospectively assessed regarding candidacy for uCI. RESULTS: Of the 118 children, 103 had completed uCI candidacy assessment, while 15 were undergoing this assessment at the time of review. More than half of children did not go on to implantation (63/103, 61%), with the 2 main reasons being (1) half (31/63) did not meet candidacy criteria for implantation, most commonly due to cochlear nerve aplasia/hypoplasia (31/82 who were assessed with MRI, 38%) and (2) families (30/103; 29%) declined participation in the surgical arm of the trial. The most common etiologies of SSD in the 37/103 (36%) children who both met candidacy and consented to implantation were congenital cytomegalovirus (cCMV; 16/37, 43%), unknown (6/37, 16%), cochleovestibular anomaly and trauma (each 5/37, 14%). CONCLUSIONS: Many children with SSD who present for implant candidacy assessment do not ultimately receive uCI. Major factors contributing to noncandidacy are cochlear nerve aplasia and parental acceptance of the intervention. While approximately half of children with SSD in our cohort were candidates for implantation, only 1/3 of the total cohort proceeded with implantation with the main predictors of acceptability of this intervention being an etiology (i.e., cCMV) that carries risk of progressive deterioration in the better hearing ear or SSD that was sudden in onset. These findings provide important insight into this new population of cochlear implant users and the emerging acceptance of intervention in children with SSD.

Stimulation parameters differ between current anti-modiolar and peri-modiolar electrode arrays implanted within the same child.

OBJECTIVE: To compare stimulation parameters of peri-modiolar and anti-modiolar electrode arrays using two surgical approaches. METHODS: Impedance, stimulation thresholds, comfortably loud current levels, electrically evoked compound action potential thresholds and electrically evoked stapedial reflex thresholds were compared between 2 arrays implanted in the same child at 5 time points: surgery, activation/day 1, week 1, and months 1 and 3. The peri-modiolar array was implanted via cochleostomy in all children (n = 64), while the anti-modiolar array was inserted via a cochleostomy in 43 children and via the round window in 21 children. RESULTS: The anti-modiolar array had significantly lower impedance, but required higher current levels to elicit thresholds, comfort, electrically evoked compound action potential thresholds and electrically evoked stapedial reflex thresholds than the peri-modiolar array across all time points, particularly in basal electrodes (p < 0.05). The prevalence of open electrodes was similar in anti-modiolar (n = 5) and peri-modiolar (n = 3) arrays. CONCLUSION: Significant but clinically acceptable differences in stimulation parameters between peri-modiolar and anti-modiolar arrays persisted four months after surgery in children using bilateral cochlear implants. The surgical approach used to insert the anti-modiolar array had no overall effect on outcomes.