The occurrence of tinnitus after CI surgery in patients with severe hearing loss: A retrospective study

Objective: An often reported side-effect of a cochlear implant (CI) is suppression of tinnitus. However, induction of tinnitus is also a known complication of CI surgery. To date, it remains unclear why some CI recipients experience larger tinnitus complaints due to CI surgery while most others do not. The goal of this study was to investigate the effect of deterioration of residual hearing due to CI surgery on tinnitus. Design: In this retrospective database study, pre- and postoperative audiometric hearing thresholds were retrieved from patients' clinical files. Furthermore, tinnitus questionnaires were sent to all patients who fitted inclusion criteria. Study sample: Of the 512 CI patients who were implanted within the last ten years, 197 patients fitted the inclusion criteria and returned the questionnaires. Results: We identified 39 cases (19.8%) who suffered from a newly developed (25) or deteriorated (14) tinnitus following CI surgery. No statistically significant association between perioperative deterioration of hearing thresholds measured by pure-tone audiometry and the development or deterioration of tinnitus was found. Conclusions: There is a small risk for deteriorated residual hearing after cochlear implantation. However, for patients with preoperative residual hearing, there appears to be no increased risk of developing chronic tinnitus after hearing deterioration due to cochlear implantation.