Vestibular function in cochlear implantation: Correlating objectiveness and subjectiveness

Abstract

Objective: To evaluate vestibular function before and after cochlear implantation (CI) STUDY DESIGN: A prospective descriptive study.

Material and methods: Thirty consecutive patients with profound sensorineural hearing loss undergoing CI. Objective assessment of vestibular function was performed with the caloric test and video head impulse test (vHIT) in patients before and after CI. Dizziness Handicap Inventory (DHI) was used for subjective assessment before and after CI.

Results: Thirty patients received CI with 21 by round window approach and nine by anteroinferior cochleostomy. Vestibular results were categorized into four groups: no changes (20 patients), changes in the caloric test and vHIT (3 patients, all with DHI changes; P = 0.0001), changes in vHIT gain but not in caloric test (3 patients, all with DHI changes; P = 0.005), no changes in the caloric test and vHIT gain but only saccades appear (4 patients, all with DHI changes; P = 0.011).

Conclusions: Although CI is a safe surgery with few major complications, it is a procedure that can produce dizziness. The vHIT reveals that 30% of patients demonstrate postoperative change in vestibular function. Therefore, when examining a CI patient with postoperative symptoms of dizziness, results of the vHIT test and gain as well as the presence of saccades, along with an increase DHI score, are parameters to consider in their evaluation.

Level of evidence: 4.

Keywords: Cochlear implant; dizziness; vestibular function; video head impulse test.