Tinnitus suppression by electrical stimulation of the cochlear wall and by cochlear implantation.

Some recent studies have reported on tinnitus suppression by electrical stimulation of the cochlear wall and by cochlear implant. In the present study, the degree of tinnitus in cochlear implant candidates was determined and the effects of promontory stimulation and cochlear implantation on tinnitus were investigated. Of the cochlear implant candidates, all of whom were either severely hearing impaired or totally deaf, 87% experienced tinnitus. When electrical stimulation was applied to the cochlear wall (promontory stimulation test), tinnitus was abolished in 23% and improved in 46% of the patients. Thus, electrical stimulation of the cochlear wall effectively suppressed tinnitus in 69% of the patients. Following cochlear implantation, tinnitus was abolished in 35% and decreased in 42%. Thus, intracochlear electrical stimulation was effective for treatment of tinnitus in 77% of the patients. The suppression of tinnitus continued for several hours after the patients switched off the implant device. In 60% of the patients whose tinnitus was suppressed or abolished after the cochlear implant surgery, tinnitus was also suppressed in the contralateral ear.