Recent advances in molecular genetic testing (MGT) have improved identification of genetic aetiology of candidates for cochlear implantation (CI). However, whether genetic information increases CI outcome predictability in post-lingual deafness remains unclear. Therefore, we evaluated the outcomes of CI with respect to genetic aetiology and clinical predictors by comparing the data of study subjects; those with an identified genetic aetiology (GD group), and those without identifiable variants (GUD group). First, we identified the genetic aetiology in 21 of 40 subjects and also observed genetic etiologic heterogeneity. The GD group demonstrated significantly greater improvement in speech perception scores over a 1-year period than did the GUD group. Further, inverse correlation between deafness duration and the 1-year improvement in speech perception scores was tighter in the GD group than in the GUD group. The weak correlation between deafness duration and CI outcomes in the GUD group might suggest the pathophysiology underlying GUD already significantly involves the cortex, leading to lesser sensitivity to further cortex issues such as deafness duration. Under our MGT protocol, the correlation between deafness duration and CI outcomes were found to rely on the presence of identifiable genetic aetiology, strongly advocating early CI in individual with proven genetic aetiologies.

Objectives. To investigate the neurocognition of aged patients with chronic tinnitus and reveal the possible association between tinnitus severity and cognitive function, with attention to mild cognitive impairment (MCI).Methods. Fifty-eight elderly patients (≥65 years old) with chronic tinnitus (≥6 months) were prospectively enrolled in this study. All patients assessed the neurocognitive batteries including the Korean version of the patient health questionnaire-9 (K-PHQ-9), the Lawton instrumental activities of daily living scale (K-IADL), and the Montreal cognitive assessment (MoCA-K). After initial evaluation to exclude moderate or severe cognitive impairment by a psychiatrist, the patients were classified into two groups: MCI and non-MCI, according to the MoCA-K scores (cutoff value, 22/23). All patients underwent audiological examinations including psychoacoustic tests of tinnitus.Results. Of 58 patients, 10 (17.2%) met the MCI criteria. The tinnitus handicap inventory (THI) score in the MCI group was significantly higher than that in the non-MCI group. Based on multivariate regression analysis, a significant association between tinnitus severity and MoCA-K score was also detected. Specifically, bothersome tinnitus (THI score ≥30) was closely linked to the presence of MCI. Meanwhile, the impact of MCI on both K-PHQ-9 and K-IADL scores was not evident in patients with chronic tinnitus.Conclusion. Tinnitus severity appears to be a potential independent determinant for predicting the MCI, suggesting the underlying mechanism between chronic tinnitus and cognitive deficit. Given that MCI highly links to dementia, the evaluation of cognitive functions in aged patients with chronic tinnitus need to be considered at the initial assessment of tinnitus.

Objective: To investigate the effects of cavitating lesions involving the internal auditory canal (IAC) in subjects with cochlear otosclerosis with regard to poststapedotomy hearing outcome. Study Design: Retrospective study. Setting: Tertiary referral center. Patients: A retrospective chart review of 134 subjects with otosclerosis treated from January 2011 to June 2017 at Seoul National University Bundang Hospital was conducted. Sixteen subjects (23 ears) with temporal bone computed tomography (TBCT)-confirmed cochlear otosclerosis who underwent stapedotomy were included in the study. Main Outcome Measures: Pure tone audiometry (PTA) (i.e., air and bone conduction; AC and BC, respectively) thresholds and air–bone gap (ABG), measured at 6 months postoperatively were compared between cochlear otosclerosis with and without IAC involvement (IAC group and non-IAC group, respectively). Results: A total of 14 of 23 ears showed involvement of the IAC. There were no significant differences in age, side of otosclerosis, or preoperative hearing threshold between the two groups. The mean postoperative AC and BC thresholds and ABG of the IAC group were significantly poorer (45.7 dB, 33.8 dB, and 11.8 dB, respectively) than those of the nonIAC group (24.1 dB, 20.0 dB, and 4.1 dB, respectively). Conclusions: Cochlear otosclerosis with cavitating lesions involving the IAC showed significantly poorer postoperative audiological outcomes than those without any cavitating lesion. Cavitation extending to the IAC may act as a third window providing a route for sound energy shunting, and thus precluding successful hearing outcome in some subjects with cavitating otosclerosis after stapedotomy.

Although tinnitus retraining therapy (TRT) based on Jastreboff’s classical neurophysiological model is efficacious in most patients, its effects on the cortical activity changes responsible for the improvement of tinnitus are still unclear. In this study, we compared pre- and post-TRT resting-state quantitative electroencephalography (rs-qEEG) findings to identify power changes that could explain TRT-induced improvements. Thirty-seven patients with severe tinnitus were enrolled in the study, and rs-qEEG data recorded before the initial TRT sessions and 6 months after TRT were compared. In addition, associations between the changes in qEEG and percentage improvements in Tinnitus Handicap Inventory (THI) scores and numeric rating scale (NRS) scores of tinnitus loudness and tinnitus perception were examined. The mean THI score decreased significantly 6 months after the initial TRT session. Also, significant improvements were observed 6 months after the initial TRT session compared with the pre-treatment scores in NRS loudness, distress, and perception. As compared with the pre-TRT status, post-TRT 6 months status showed significantly decreased powers in the left primary and secondary auditory cortices for the gamma frequency band. Changes in the alpha 1 frequency band power in the right insula and orbitofrontal cortex (OFC) appeared to be positively correlated with the percentage changes in NRS distress. These results suggested that TRT improved tinnitus-related distress by reducing the power of the top-down autonomic response modulator or peripheral physiological responses to emotional experiences. That is, TRT induced habituation via modulation of functional connections between the auditory system and the limbic and autonomic nervous systems. Our results confer additional basis for understanding the neurophysiological model and the newly suggested integrative model of tinnitus by De Ridder et al. (2014) in the context of the long-term efficacy of TRT.