Vestibular dysfunction and postural balance in cochlear implant users: a narrative literature review

Juliana Jandre Melo,Paula Carolina Dias Gibrin,Luciana Lozza De Moraes Marchiori

doi:10.1590/1982-021620182019016

Abstract

ABSTRACT Cochlear implants directly stimulate nerve fibers and ganglion cells of the auditory nerve, which transform sound energy into low levels of electrical current, stimulating the remaining fibers of the auditory nerve in patients with severe to profound hearing loss, in order to provide the significant range of auditory sensation and speech comprehension. Due to the close relationship between cochlea and vestibular receptors, some patients may present vestibular and postural balance changes concomitantly after surgery. This study aimed to perform a narrative review of the main studies that relate vestibular symptoms in patients implanted in the last six years. The research was performed through the databases: SciELO, LILACS and PubMed, using associated descriptors for "cochlear implant", "vestibular dysfunction", "vertigo" and "balance", totalizing 21 studies that fitted the inclusion criteria. The results were described in a chronological order of publication, showing the main conclusions. Of the total studies analyzed, 18 related vestibular function to cochlear implant and only 3 studies did not find such a relationship. The literature characterize the effects of the cochlear implant on the vestibular system, however, the results are contradictory.

Highlights

The cochlear implant (CI) represents the most important advance in the treatment of persons with severe and profound hearing disability[1]
Since some patients evolved with dizziness after CI, researches have been carried out correlating vestibular tests in time before and after the surgery, according to a literature review carried out in the period from 1977 to 20082, in large part, the results proved to be controversial
As criteria for inclusion of studies, it was opted to select prospectives and retrospectives and with comparison pre and after CI, with option of researches developed with children and adults of both genders and different ages, which evaluated the results of the balance after the uni or bilateral CI, available in its entirety in Portuguese and English, in the pre-set time period

Summary

Introduction

The cochlear implant (CI) represents the most important advance in the treatment of persons with severe and profound hearing disability[1]. This implant has the purpose to stimulate, directly, the nervous fibers and the ganglion cells of the auditory nerve[2], which are damaged or are not present, transforming the sound energy at low levels of electrical current, stimulating the remaining fibers of the auditory nerve[3], in order to provide a significant range of the auditory sensation and the speech comprehension. No more doubts that the CI can bring benefits to children with pre-lingual hearing disability. For pre and postoperative monitoring of patients with CI, it is necessary the work of a multidisciplinary team capable of performing several evaluations and procedures, being such a team consisting of an otological surgeon, professionals in the areas of neurology, Pediatrics, Genetics, psychology, social assistance and speech therapy, in which the later professional is responsible for vestibular, auditory and language rehabilitation[1,3]

Objectives

Methods

Findings

Conclusion