VESTIBULAR FUNCTIONS IN UNILATERAL COCHLEAR IMPLANT USERS WITH VERTIGO AND DIZZINESS

Material and Methods: In this retrospective study, the vHIT, VEMPs, and caloric test results of 12 unilateral CI users (28.0 ± 19.4) with normal inner ear structures who applied to our clinic due to vertigo and dizziness complaints between January 2018 and September 2021 test were analyzed.

Results: In this study, the most common vestibular symptom (n=7, 58%) in unilateral CI users was determined as positional vertigo. High-frequency VOR gains on the implant side were within normal limits in 67% (n=8) of individuals, while it was below normal limits in 33% (n=4). On the implant side, 73% of individuals had abnormal saccular functions, while on the non-implant side, 27 % of them had abnormal saccular functions (p > 0.05). On the non-implanted side, 64% of individuals had abnormal utricular functions; on the implanted side, 100% of individuals experienced vestibular loss in utricular functions (p > 0.05). The caloric test revealed that 5 of 7 people (71%) showed unilateral caloric weakness on the cochlear implant side.

Conclusion: Regular vestibular examination in the post-implantation period is suggested in unilateral CI users with vertigo and dizziness. It is really critical to use the complete vestibular test battery to follow-up the vestibular functions of CI users. It should also be kept in mind that CI users are at risk for BPPV in the future. Keywords : Cochlear implant, vertigo, dizziness, video head impulse test, vestibular evoked myogenic potentials, caloric test