Can cochlear implants decrease tinnitus?

Suppression of tinnitus by electrical stimulation via a cochlear implant has been studied in recent years. Some individuals who undergo cochlear implant surgery report total or partial relief of the symptoms even in the contralateral ear. The mechanisms involved in this suppression are not clear. The results obtained in our study demonstrated an improvement of 71% in 29 implant cases, confirming data found in the literature. Our aim was to study tinnitus in individuals before surgery and after cochlear implant activation and to observe improvement in the perception of tinnitus, comparing these results with data in the literature. We conducted a retrospective study of 29 postlingual adults who had profound sensorineural hearing loss and underwent cochlear implant surgery at the cochlear implant sector of the Otorhinolaryngology, Head and Neck Surgery Department, University of Campinas, São Paulo, Brazil, between May 2003 and June 2005. The device employed in this procedure was the Nucleus 24K multichannel device (Cochlear Ltd, Lane Cove, Australia). After the internal component was activated, patients completed a questionnaire. Before surgery, 21 of the 29 patients (72%) who later underwent cochlear implant surgery presented with tinnitus, which was bilateral in 14 cases (67%). After the cochlear implant was activated, seven patients (33%) presented with total suppression, and eight patients (39%) reported partial relief. In the 14 cases with bilateral symptoms, tinnitus was totally suppressed or decreased in both ears in 12 cases (86%). Individuals who underwent multichannel cochlear implant surgery presented with reduced tinnitus even in the contralateral ear.