Role of Vestibular Function Tests in Cochlear Implantation

Abstract

Objective: Vestibular function tests are often undertaken before cochlear implantation, in part to help select the side of surgery. We aim to determine whether implantation on the side of better vestibular function leads to greater dizziness than implantation on the side of worse or similar function. Method: A total of 177 unilateral implant recipients were reviewed in 2 groups. A: Those implanted in the ear with worse or similar caloric function. B: Those implanted in the ear with greater (>20%) caloric function. All were assessed with the Dizziness Handicap Inventory and supplementary questions after a minimum 2 months. Results: A total of 57% of both groups reported dizziness in the first 7 days postoperatively. At 2 months 20% of group A and 34% of group B experienced some dizziness. A total of 14% of group A and 10% of group B felt that cochlear implantation had resulted in impaired balance. The DHI scores of 86% of group A (median score 0) and 76% of group B (median score 10) corresponded with low handicap. None of these results differed significantly between groups A and B. Conclusion: While cochlear implantation may result in dizziness it is almost always short-lived and mild, even when the ear with a stronger caloric response is implanted.