Conductive hearing loss during development does not appreciably alter the sharpness of cochlear tuning.
AUDITORY pathways; CONDUCTIVE hearing loss; HAIR cells; SENSORINEURAL hearing loss; SIGNAL-to-noise ratio
An increasing number of studies show that listeners often have difficulty hearing in situations with background noise, despite normal tuning curves in quiet. One potential source of this difficulty could be sensorineural changes in the auditory periphery (the ear). Signal in noise detection deficits also arise in animals raised with developmental conductive hearing loss (CHL), a manipulation that induces acoustic attenuation to model how sound deprivation changes the central auditory system. This model attributes perceptual deficits to central changes by assuming that CHL does not affect sensorineural elements in the periphery that could raise masked thresholds. However, because of efferent feedback, altering the auditory system could affect cochlear elements. Indeed, recent studies show that adult-onset CHL can cause cochlear synapse loss, potentially calling into question the assumption of an intact periphery in early-onset CHL. To resolve this issue, we tested the long-term peripheral effects of CHL via developmental bilateral malleus displacement. Using forward masking tuning curves, we compared peripheral tuning in animals raised with CHL vs age-matched controls. Using compound action potential measurements from the round window, we assessed inner hair cell synapse integrity. Results indicate that developmental CHL can cause minor synaptopathy. However, developmental CHL does not appreciably alter peripheral frequency tuning.
Ye Y; Ihlefeld A; Rosen MJ
Scientific Reports
2021
2021-02-17
journalArticle
<a href="http://doi.org/10.1038/s41598-021-83115-1" target="_blank" rel="noreferrer noopener">10.1038/s41598-021-83115-1</a>
Use of biologics for treatment of autoimmune inner ear disease
Objective: Biologic medications are novel therapeutics in the treatment of Autoimmune Inner Ear Disease (AIED), an etiology of Sensorineural Hearing Loss (SNHL). The goal of this study is to review the currently available literature on the efficacy of biologic medications on autoimmune-mediated hearing loss and associated symptomology among patients with AIED.
Methods: A systematic review of Pubmed, Scopus, Cochrane, and Web of Science databases was conducted to identify studies investigating the impact of biologic medications on hearing outcomes. Bias assessment was independently conducted by three authors and studies were stratified based on risk of bias.
Results: Of 174 unique abstracts screened, 12 articles met inclusion criteria for formal review. One randomized control trial, seven prospective cohort studies, and four retrospective cohort studies were included. Seven biologic medications, Etanercept, Infliximab, Adalimumab, Golimumab, Rituximab, Anakinra, and Canakinumab, were identified targeting three unique molecular targets, TNF-α, CD20, and IL-1.
Conclusion: The effects of biologic medications in treating SNHL was highly variable without clear efficacy of a drug or drug category, likely due to rarity of disease, multifactorial etiologies of AIED, and cohort heterogeneity. However, several medications alleviate symptoms associated with AIED, such as vertigo and tinnitus. While biologic medications may be promising therapeutics in AIED patients, the evidence is currently inconclusive. Large-scale randomized control trials and prospective cohort reviews are required to establish the efficacy of biologic medications in treating hearing loss.
Bailey Balouch
Ryan Meehan
Aishwarya Suresh
Haniah A Zaheer
Abdur Rahman Jabir
Anas M Qatanani
Vishal Suresh
Syed Z Kaleem
Brian J McKinnon
Am J Otolaryngol
. 2022 Sep-Oct;43(5):103576. doi: 10.1016/j.amjoto.2022.103576. Epub 2022 Aug 5.
2022
English