Browsing by Subject "Sensorineural hearing loss"

Now showing 1 - 3 of 3
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    A multi-channel EEG mini-cap can improve reliability for recording auditory brainstem responses in chinchillas
    (Elsevier, 2023) Ginsberg, Hannah M.; Singh, Ravinderjit; Bharadwaj, Hari M.; Heinz, Michael G.; Neurology, School of Medicine
    Background: Disabling hearing loss affects nearly 466 million people worldwide (World Health Organization). The auditory brainstem response (ABR) is the most common non-invasive clinical measure of evoked potentials, e.g., as an objective measure for universal newborn hearing screening. In research, the ABR is widely used for estimating hearing thresholds and cochlear synaptopathy in animal models of hearing loss. The ABR contains multiple waves representing neural activity across different peripheral auditory pathway stages, which arise within the first 10 ms after stimulus onset. Multi-channel (e.g., 32 or higher) caps provide robust measures for a wide variety of EEG applications for the study of human hearing. However, translational studies using preclinical animal models typically rely on only a few subdermal electrodes. New method: We evaluated the feasibility of a 32-channel rodent EEG mini-cap for improving the reliability of ABR measures in chinchillas, a common model of human hearing. Results: After confirming initial feasibility, a systematic experimental design tested five potential sources of variability inherent to the mini-cap methodology. We found each source of variance minimally affected mini-cap ABR waveform morphology, thresholds, and wave-1 amplitudes. Comparison with existing method: The mini-cap methodology was statistically more robust and less variable than the conventional subdermal-needle methodology, most notably when analyzing ABR thresholds. Additionally, fewer repetitions were required to produce a robust ABR response when using the mini-cap. Conclusions: These results suggest the EEG mini-cap can improve translational studies of peripheral auditory evoked responses. Future work will evaluate the potential of the mini-cap to improve the reliability of more centrally evoked (e.g., cortical) EEG responses.
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    A single-cell level comparison of human inner ear organoids with the human cochlea and vestibular organs
    (Cell Press, 2023) van der Valk, Wouter H.; van Beelen, Edward S. A.; Steinhart, Matthew R.; Nist-Lund, Carl; Osorio, Daniel; de Groot, John C. M. J.; Sun, Liang; van Benthem, Peter Paul G.; Koehler, Karl R.; Locher, Heiko; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Inner ear disorders are among the most common congenital abnormalities; however, current tissue culture models lack the cell type diversity to study these disorders and normal otic development. Here, we demonstrate the robustness of human pluripotent stem cell-derived inner ear organoids (IEOs) and evaluate cell type heterogeneity by single-cell transcriptomics. To validate our findings, we construct a single-cell atlas of human fetal and adult inner ear tissue. Our study identifies various cell types in the IEOs including periotic mesenchyme, type I and type II vestibular hair cells, and developing vestibular and cochlear epithelium. Many genes linked to congenital inner ear dysfunction are confirmed to be expressed in these cell types. Additional cell-cell communication analysis within IEOs and fetal tissue highlights the role of endothelial cells on the developing sensory epithelium. These findings provide insights into this organoid model and its potential applications in studying inner ear development and disorders.
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    Cochlear Implantation in US Military Veterans: A Single Institution Study
    (Sage, 2023-05-12) Totten, Douglas J.; Saltagi, Abdul; Libich, Karen; Pisoni, David B.; Nelson, Rick F.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Objective: Military veterans have high rates of noise-induced hearing loss (NIHL) which is associated with more significant spiral ganglion neuronal loss. This study explores the relationship between NIHL and cochlear implant (CI) outcomes in veterans. Study design: Retrospective case series of veterans who underwent CI between 2019 and 2021. Setting: Veterans Health Administration hospital. Methods: AzBio Sentence Test, Consonant-Nucleus-Consonant (CNC) scores, and Speech, Spatial, and Qualities of Hearing Scale (SSQ) were measured pre- and postoperatively. Linear regression assessed relationships between outcomes and noise exposure history, etiology of hearing loss, duration of hearing loss, and Self-Administered Gerocognitive Exam (SAGE) scores. Results: Fifty-two male veterans were implanted at an average (standard deviation) age of 75.0 (9.2) years without major complications. The average duration of hearing loss was 36.0 (18.4) years. The average time of hearing aid use was 21.2 (15.4) years. Noise exposure was reported in 51.3% of patients. Objectively, AzBio and CNC scores 6 months postoperatively showed significant improvement of 48% and 39%, respectively. Subjectively, average 6-month SSQ scores showed significant improvement by 34 points (p < .0001). Younger age, SAGE score ≥17, and shorter duration of amplification were associated with higher postoperative AzBio scores. Greater improvement in AzBio and CNC scores was associated with lower preoperative scores. Noise exposure was not associated with any difference in CI performance. Conclusion: Despite high levels of noise exposure and advanced age, veterans derive substantial benefits from cochlear implantation. SAGE score ≥17 may be predictive of overall CI outcomes. Noise exposure does not impact CI outcomes.