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.