Predictors of vestibulo-ocular reflex gain changes in cochlear implanted children.

INTRODUCTION: Using a video head impulse test (vHIT) remote camera, risk factors of changes in vestibulo-ocular reflex (VOR) gain in children after cochlear implantation (CI) were studied. METHODOLOGY: Tertiary center prospective case study included 63 pediatric CI cases: 21 children were implanted unilaterally and 21 bilaterally. VOR gain of semicircular canals (SCCs) was measured before CI and at two follow-up points (4 months and 1 year post-implantation). Analyzed were impacts of electrode length, insertion difficulty, inner ear morphology, etiology, neonatal intensive care unit (ICU) stay, muscle hypotonia, and motor development delay on VOR gain changes. vHIT success rates were compared across age categories. RESULTS AND DISCUSSION: CI affects VOR gain for posterior SCC, albeit within physiological borders. CI's safety for the ampullar compartment was confirmed. Nevertheless, children with inner ear malformations, ICU stays, muscle hypotonia, or delayed motor development showed decreased VOR gain, particularly in posterior SCC. Except for transient decrease in cases of more difficult surgeries, electrode length and insertion difficulty did not significantly influence VOR gain. Analysis by etiology identified DFNB1 as a risk factor for negative relationship to posterior SCC VOR gain. vHIT is highly feasible, especially for lateral SCC (97%), across all pediatric age groups and routinely should be included in CI programs.