Audiological Outcomes and Map Characteristics in Children with Perimodiolar and Slim Straight Array Cochlear Implants in Opposite Ears

Objective: To identify differences in outcomes and map characteristics in pediatric bilateral cochlear implants with modiolar conforming and lateral wall arrays in opposite ears. Study Design: Retrospective case series. Setting: Tertiary care pediatric referral center. Patients: Fourteen children who received a perimodiolar array in one ear and a slim straight array in the opposite ear in sequential surgeries. Interventions: None. Main Outcome Measures: Consonant-nucleus-consonant test (CNC) word recognition score, battery life, power levels, electrical compound action potential (ECAP) thresholds, and electrical threshold and comfort charge levels. Results: Speech perception outcomes were poorer in the lateral wall ears than the perimodiolar ears, and scores in the bilateral condition were better than with the lateral wall device alone. Sequential placement was a factor with differences in preoperative candidacy time correlating with greater difference in speech perception. There was no difference in charge levels between ears, in spite of higher ECAP threshold values for the lateral wall devices. Conclusion: While bilateral speech perception was good, speech perception with the lateral wall device alone was poorer. This cannot be explained solely by the device, as differences in preoperative candidacy time were a significant factor. ECAP thresholds are significantly higher for lateral wall electrodes, but that did not translate in to higher psychophysical measurements.