The effect of cochlear implantation on tinnitus in patients with bilateral hearing loss : A systematic review

OBJECTIVES: To present an overview of the effect of cochlear implantation on tinnitus in adults with bilateral sensorineural hearing loss. DATA SOURCES: PubMed, Cochrane Library, CINAHL, and Embase databases were searched for articles from database inception up to January 13, 2015. METHODS: A systematic search was conducted. Original studies reporting on cochlear implantation and the effect on tinnitus, measured with a tinnitus questionnaire, were included. The directness of evidence and risk of bias were assessed. Studies with a moderate or high directness of evidence and a low or moderate risk of bias were included for analysis. The pre- and postimplantation tinnitus scores were extracted. RESULTS: In total, 786 unique articles were retrieved. Although there was lack of high level of evidence studies, 10 articles satisfied the eligibility criteria. Overall, there was a reduction of mean tinnitus score. There was a decrease in tinnitus score in 25% to 72%, and a total suppression of tinnitus after implantation was reported in 8% to 45% of patients. Tinnitus was stable in 0% to 36% of patients, and increase of tinnitus occurred in 0% to 25%. Tinnitus induction rates in the patients without preoperative tinnitus varied from 0% to 10%. CONCLUSIONS: There are no high level of evidence studies concerning cochlear implantation and the effect on tinnitus. Overall, current literature shows that there is a decrease of mean tinnitus questionnaire score after unilateral cochlear implantation. However, there is also a chance of increasing burden of existing tinnitus, and the induction of tinnitus is reported. LEVEL OF EVIDENCE: NA Laryngoscope, 125:2584-2592, 2015