Limitation of High Pitch Sound Perception in Nontumor Patients with Auditory Brainstem Implantation

Hyun Seung Choi, Jae Young Choi, In Seok Moon, Mi Ran Bae, Bo Gyung Kim, Minbum Kim, Jin Woo Chang, Junhui Jeong
2018 Korean Journal of Otorhinolaryngology - Head and Neck Surgery  
and ObjectivesZZAuditory brainstem implantation (ABI) is another option for hearing rehabilitation in non-neurofibromatosis type 2 patients who cannot undergo cochlear implantation (CI). However, the average performance of ABI is worse than that of CI. We analyzed the psycho-electrical parameters of each electrode and psycho-acoustic response to different frequency sounds in nontumor patients with ABI. Subjects and MethodZZSixteen patients with ABI from July 2008 to May 2013 were included in
more » ... were included in the study. They were followed up for 4 to 56 months. Among them, 12 were prelingual deaf with a narrow internal auditory canal or cochlear ossification. The remaining four were postlingual deaf adults with severely ossified cochleae. We analyzed the electrical parameters [impedance, threshold level (T level), and dynamic range] of each of the 12 electrodes. We also evaluated the sound field pure-tone threshold, Ling 6 sound detection-identification test (Ling 6 test), and pitch ranking data of these patients. ResultsZZThe impedance, T level, and dynamic range did not significantly differ among electrodes. However, the pure-tone threshold to sound field stimulation was elevated in the high tone area, where more variables were found than in the low frequency area. Patients could not identify /S/ and /Sh/ sounds in the Ling 6 test. The mean T level and the dynamic range of the three highest pitch-perceiving electrodes in each patient was higher and narrower, respectively, than those of the three lowest pitch-perceiving electrodes. ConclusionZZThe nontumor patients with ABI have difficulty perceiving high pitch sound. More sophisticated penetrating type electrodes and, if possible, bimodal stimulation with CI, could be considered. Key WordsZZ Auditory brainstem implantation ㆍCochlear ossification ㆍ Narrow internal auditory canal ㆍNontumor ㆍOutcomes. Otology Korean J Otorhinolaryngol-Head Neck Surg 2018;61(5):235-41 / pISSN 2092-5859 / eISSN 2092-6529
doi:10.3342/kjorl-hns.2017.00444 fatcat:67skcsf5vrcmvann7huozkeiwi