Preliminary results of video Head Impulse Testing (vHIT) in children with cochlear implants.

Objective: To evaluate the lateral semicircular canal high frequency vestibulo-oculomotor reflex (LSC HF VOR) in children with cochlear implant.

Methods: 16 children (10 females and 6 males, age range = 5-17 years) receiving a unilateral (n = 12) or a bilateral (n = 4) cochlear implant were included and compared to a control group of 20 age-matched normal-hearing (NH) children. Both implanted and NH children received a vestibular function test battery, including a Vestibulo-Ocular Reflex (VOR) gain assessment by means of a video-Head Impulse Test (vHIT), which represented the main outcome measure. In implanted subjects, vHIT was measured on both sides in the "CI-ON" and "CI-OFF" conditions.

Results: Overall, no significant LSC HF VOR gain difference was found between CI users and NH peers. In the unilaterally implanted group, the LSC HF VOR gain measured in the "CI-ON" condition was significantly higher than in the "CI-OFF" condition, both in the implanted and in the non-implanted ear. In the bilaterally implanted group there was no such a difference between the two conditions, on either side.

Conclusion: This is the first study investigating the LSC HF VOR gain in children with unilateral and bilateral CI. The study demonstrates that the LSC HF VOR of bilaterally implanted children is comparable to normal hearing children.