Vestibular Function in Cochlear Implantation With a Focus on Preoperative and Postoperative Testing in the Adult Population: A Scoping Review

BACKGROUND: Currently, there is an absence of standardized vestibular guidelines governing cochlear implant candidacy criteria and postoperative evaluations. In response to this gap, a scoping review was completed to help identify trends among the literature regarding preoperative and postoperative testing. PURPOSE: The primary goal of this study was to improve understanding of vestibular outcomes within the cochlear implant population, particularly the adult population, and to support referrals for preoperative and postoperative vestibular testing. METHOD—ELIGIBILITY CRITERIA: To be included in this review, articles were composed of adult cochlear implant recipients and analyze preoperative and/or postoperative vestibular test measures such as video head impulse test, vestibular evoked myogenic potentials (VEMPs), caloric irrigations, videonystagmography, posturography, or functional vestibular tests. Articles were published through PubMed from 2017 to 2024 and were available in English. RESULTS: There were 35 articles selected for a final review. The studies revealed recurring themes that highlight considerations such as age-related factors, postoperative subjective symptoms, and the composition of the vestibular assessment. The most common vestibular test measures, notably abnormal postoperatively, were caloric irrigations and cervical VEMPs. The current literature is lacking in data regarding the late-life population, particularly those over the age of 80 years. However, of the population tested, it is noted that impact from cochlear implantation may be greater for the aging group. Additionally, the overall quality of the articles included were at a higher risk of bias and typically consisted of small sample sizes. CONCLUSIONS: Cochlear implantation leads to a risk for vestibular impairment, primarily of the horizontal semicircular canal and/or saccule. This risk could increase with age; however, literature is lacking objective data on the older adult population, particularly over the age of 80 years. As a future direction for this work, research could focus on vestibular outcomes and appropriate protocols for older cochlear implant recipients.