Neurotology Fellow UC San Diego San Diego, California
Objectives: Describe the nuances regarding cochlear implant(CI) fitting and programming in children with cochleovestibular nerve(CVN) abnormalities.
Study Design: Retrospective case series examining patients with abnormal CVN with marginal benefit from CI. followed by reprogramming by an audiologist.
Setting: Outpatient.
Patients: Pediatric CI patients with abnormal CVNs and with unsatisfactory hearing outcomes.
Interventions: Following CI, patients underwent reprogramming and adjustment with an audiologist.
Main Outcome Measures: Clinical features, hearing data, imaging, and CI settings.
Results: Nine CI patients(16 ears) were included. Imaging data was available for four patients(7 ears). Mean imaging age was 8 months(range 4-12). Five had an abnormal modiolus and all had a normal cochlea. Six (85%) ears had an absent CVN within the internal auditory canal. Mean implantation age was 40 months (range 12-138). Nine ears had preprogramming by an outside audiologist prior to reprogramming by audiologist (J.H.). In all patients, all electrodes were activated across all frequencies. Following reprogramming, all CIs had stimulation reduced. Five (56%) had a pulsewidth reduction. Additionally, 5(28%) had all electrodes activated, 6(33%) had low frequencies deactivated, 4(22%) had high frequencies deactivated, and 1(6%) had a mixture of frequencies deactivated. Following reprogramming, hearing perception was available for 8 CIs. The average speech recognition threshold was 35 (range 25-50). An open-set word list was used for 6(75%) ears. Word percentile perception was over 50% in 3(38%) CIs.
Conclusions: All patients benefited from CI, despite many having an absent CVN. Aside from the surgical pitfalls associated with implantation, this subset of patients may require nontraditional CI programming with specific electrode frequency activation to maximize hearing benefit.
Define Professional Practice Gap & Educational Need: The canonical thought is that CIs are ineffective or have unpredictable response in patients with abnormal CVN and hearing loss; thus, these patients often do not undergo implantation. We present a case series demonstrating that bilateral implantation and CI programing strategies improved hearing outcomes in this population.
Learning Objective: Illustrate that pediatric patients with abnormal CVNs can benefit from CIs, and clarify the nuances in their CI settings.
Desired Result: Encourage physicians and audiologists encountering patients with abnormal CVNs to consider bilateral cochlear implantation, and a corresponding reprograming methodology. We hope to bring awareness to the CI programming modifications specific to this population.
Level of Evidence: Level V
Indicate IRB or IACUC: University of California, San Diego IRB #190938: Congenital hearing loss