Audiometric performance and tinnitus suppression in an Auditory Brainstem Implant Patient with unilateral profound sensorineural hearing loss.

Background: Cochlear implantation (CI) has been found to be an effective technique for hearing restoration and tinnitus suppression in patients with severe to profound sensorineural hearing loss and ipsilateral incapacitating tinnitus. While the effects of CI on tinnitus is an aria of active investigation, the effect of electrical brainstem stimulation by use of an auditory brainstem implant (ABI) on tinnitus perception has scarcely been reported and mainly in NF2 patients. Aim of the study: To investigate the effects of auditory brainstem implantation in a patient with unilateral profound sensorineural hearing loss and incapacitating tinnitus. Methods: The present study reports on a case study of a 59 - year - old male patient with an asymmetrical sensorineural hearing loss with ipsilateral incapacitating tinnitus after labyrinthitis. First, the patient underwent cochlear implantation (MED-EL Pulsar100 FL) in the deaf ear. In the contralateral ear, he was wearing a hearing aid. Due to obliteration of the cochlea, the electrode array could only be partially (4 electrodes) inserted. Consequently, hearing performance was unsatisfactory and tinnitus suppression decreased over time until there was only minimal tinnitus suppression. Therefore, the patient received an ABI (MED-EL Concerto) at the same ear 6 years post-cochlear implantation. He was evaluated pre- ABI implantation and up to 5 years after ABI implantation. Audiological test battery comprised free field pure-tone audiometry (PTA500, 1000 and 2000Hz), speech perception in quiet (phonetically balanced monosyllabic word lists) and in noise (LIST sentences). Tinnitus was assessed with the Visual Analogue Scale for loudness (VAS). Results: Daily ABI use was reported by the patient. A PTA(500, 1000 and 2000Hz) of 45 dB HL with ABI was obtained. With activation of the ABI, the tinnitus decreased. Pre- implantation, the tinnitus loudness was rated 9.3/10 on the VAS and was reduced to 3/10 12 months after ABI implantation, 5/10 36 months post-ABI and 4.5/10 after 48 months. When the ABI was switched off, tinnitus immediately appeared with a loudness of 8-9/10 on the VAS. The patient obtained a 61% score on the Dutch opens set monosyllabic word list (NVA) at the 48 month interval with ABI alone, 45% with hearing aid only and a 94% score with the combination of the ABI and the contralateral hearing aid. 4 years after the ABI implantation, speech in noise scores showed a speech to noise ratio from +10 dB SNR with ABI only, +7 dB SNR with hearing aid alone and +4 dB SNR with the combination of the ABI and a contralateral hearing aid Conclusion: This case study reports on a patient with unilateral profound sensorineural hearing loss and ipsilateral incapacitating tinnitus after labyrinthitis. The patient benefitted from tinnitus suppression and improved speech recognition in quiet and in noise through auditory brainstem implantation at the deaf side. [ABSTRACT FROM AUTHOR]