Tinnitus & Cochlear Implants

A cochlear implant is an electronic device that can help to restore hearing in patients who have severe bilateral sensorineural hearing loss. This thesis aims to obtain more insight into the number of patients that might benefit from cochlear implantation concerning tinnitus. We did two questionnaire studies, which showed that the prevalence of tinnitus in cochlear implant patients is 51-66%. The tinnitus severity is generally mild to moderate. Cochlear implantation reduces tinnitus in an important part of the patients (56-75%), but in a small part of the patients (0-28%) cochlear implantation has a negative influence on tinnitus. However, in the patients who show tinnitus deterioration the tinnitus handicap does not increase and in the patients who show tinnitus onset after implantation the tinnitus handicap is mild. Based on the questionnaire studies we created a prognostic model that showed that the lower the preoperative tinnitus handicap and the preoperative hearing handicap, the higher the chance that cochlear implantation will worsen tinnitus. This result suggests that preoperative screening with tinnitus- and hearing handicap questionnaires could be meaningful. Further, we performed a study in which we explored single electrode stimulation to reduce tinnitus perception. We found that the effect of single-electrode stimulation on tinnitus is relatively small in comparison to the effect of full-array stimulation, but in some cases sustained single electrode stimulation may be beneficial for tinnitus management.