Impaired fixation suppression is a risk factor for vertigo after cochlear implantation

Abstract

To analyse the correlation between visual fixation suppression test results and the occurrence of post-operative vertigo in patients receiving a cochlear implant, and to compare this with other possible risk factors. In a prospective study setting, caloric vestibular responses, visual fixation suppression and subjective vertigo symptoms were assessed in 59 adult patients undergoing cochlear implantation. These parameters were compared in patients with post-operative vertigo versus vertigo-free patients. Vertigo symptoms were reported by 49 per cent of patients. Thirty-nine per cent of the patients had a decrease in caloric response on the implanted side. There was no statistically significant difference between the two patient groups regarding canal paresis, age, sex, implanted electrode type, implant side, surgeon, cause of deafness, petrous bone computed tomography findings and incidence of pre-operative vertigo. Patients with post-operative vertigo had a significantly greater prevalence of insufficient visual fixation suppression. All patients who suffered long-term post-operative vertigo had insufficient visual fixation suppression. Pre-operative impaired visual fixation suppression is a major risk factor for the occurrence of vertigo after cochlear implantation.