Affiliations: [a] Department of Surgery, Otolaryngology, University of Melbourne
| [b] Department of Surgery, Faculty of Medicine, Nursing and Health Sciences, Monash University
| [c] Royal Victorian Eye and Ear Hospital, Melbourne | [d] Department of Psychology, University of Sydney
Correspondence:
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Corresponding author: Prof Stephen O’Leary, Department of Surgery, Otolaryngology, University of Melbourne, Royal Victorian Eye and Ear Hospital. 32 Gisborne St, Melbourne East, 3002, Australia. Tel.: +613 9929 8366; Fax: +613 9663 1958; E-mail: sjoleary@unimelb.edu.au.
Abstract: BACKGROUND:Dizziness is a common perioperative complication after cochlear implantation (CI). To date, the exact cause behind this phenomenon remains unclear. There is recent evidence to suggest that otolith function, specifically utricular, may be affected shortly after CI surgery, however whether these changes are related to patient symptoms has not yet been investigated. OBJECTIVE:To determine whether CI surgery and perioperative dizziness is associated with changes in utricular function. METHODS:We performed an observational study on patients undergoing routine CI surgery. Utricular function was assessed using the Subjective Visual Vertical (SVV), and perioperative dizziness was determined using a questionnaire. The study followed patients before surgery and then again 1-day, 1-week and 6-weeks after implantation. RESULTS:Forty-one adult CI recipients participated in the study. The SVV deviated away from the operated ear by an average of 2.17° a day after implantation, 0.889° 1 week and –0.25° 6 weeks after surgery. Dizziness contributed to a tilt of 0.5° away from the implanted ear. These deviations were statistically significant. CONCLUSIONS:CI surgery causes utricular hyperfunction in the operated ear that resolves over 6 weeks. SVV tilts were greater in participants experiencing dizziness, suggesting that utricular hyperfunction may contribute to the dizziness.
