Cochlear Implantation in Ménière's Disease With and Without Labyrinthectomy.

OBJECTIVE: To investigate outcomes of cochlear implantation (CI) in patients with Ménière's disease (MD) with and without surgical labyrinthectomy. STUDY DESIGN: Retrospective study. SETTING: Multiple tertiary referral centers. SUBJECTS: Thirty one ears from 27 patients (17 men, 10 women, aged 42-84) with CI in ipsilateral MD ear. INTERVENTION: CI in ears with intact labyrinths (Group 1), CI with simultaneous surgical labyrinthectomy (Group 2), and CI sequential to surgical labyrinthectomy (Group 3). MAIN OUTCOME MEASURE: Within-subject improvement on Bamford Kowal Bench test or City University of New York open set sentence tests. RESULTS: Majority of ears achieved excellent open-set speech recognition by 12 months post-CI, irrespective of intervention group. Preoperative details including patient age and sex, implant, MD and previous intervention, and audiological test results did not significantly affect outcomes. Patients with MD undergoing CI only may experience vestibular dysfunction which may cause long-term concerns. Incidental finding was noted of eight ears with fluctuating symptoms in ipsilateral ear during 12-month period post-CI, with five of eight ears showing objective fluctuating impedances and mapping. CONCLUSION: CI in MD can yield good hearing outcomes in all three groups and this is possible even after a long delay after labyrinthectomy. Bilateral MD patients are complex and prospective quality of life (QoL) measures would be beneficial in being better able to manage the vestibular outcomes as well as the audiological ones.

Cochlear Implant Impedance Fluctuation in Ménière's Disease: A Case Study.

OBJECTIVE: To contribute to the understanding of hearing fluctuation in Ménière's disease (MD) by disseminating a case study of a cochlear implanted ear with ongoing fluctuation of electrode impedances with episodic tinnitus and no associated vestibular symptoms. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral audiology clinic. PATIENT: Man, born in 1936, with a total hearing loss in the right ear because of Mumps at age 8 years and a fluctuating progressive hearing loss in the left ear because of Ménière's disease since age 63 years. INTERVENTION: Sequential bilateral cochlear implantation right ear in August 2002 and left ear in March 2006. MAIN OUTCOME MEASURE: Impedance measurements of implanted intracochlear electrodes via common ground stimulation using proprietor programming software. RESULTS: Electrode impedances in the MD showed significant ongoing variation since implantation, whereas the contralateral non-MD ear remained stable over a period of 9 years. CONCLUSION: Electrode impedances in the ear with MD showed a variation pattern similar to that found in the hearing fluctuation characteristic of the disease. These findings raise the possibility that the same physiological mechanisms of hearing fluctuation may be responsible for intracochlear electrode impedance changes. We hypothesize that impedance fluctuation is because of changes in the permeability of the blood-labyrinth barrier because of cyclic immune activity in the inner ear which alters the electrical resistance between scala tympani and blood.