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Published on: July 28, 2022
Cochlear third window in the scala vestibuli: an animal model
Michal Preis1, Joseph Attias, Tuvia Hadar
1Department of Otorhinolaryngology and Head and Neck Surgery, Rabin Medical Center, Beilinson Campus, Petach Tikva, Israel. mickiep@bezeqint.net
Summary
Creating a cochlear third window in fat sand rats significantly reduced air-conducted sound sensitivity. This finding supports the theory that a third mobile होईलwindow in the cochlea impacts hearing thresholds.
Area of Science:
- Otolaryngology
- Auditory Neuroscience
- Inner Ear Physiology
Background:
- A pathologic third window, often involving the superior semicircular canal, is a known condition affecting hearing.
- Investigating a cochlear third window provides insights into auditory function and potential therapeutic targets.
Purpose of the Study:
- To investigate the impact of a surgically created cochlear third window in the scala vestibuli on auditory thresholds.
- To utilize the unique inner ear anatomy of fat sand rats for surgical accessibility.
Main Methods:
- A cohort of 7 healthy fat sand rats (10 ears) underwent surgical induction of a third window over the scala vestibuli.
- Auditory brainstem responses (ABRs) were measured using air and bone conduction before and after fenestration.
- Care was taken to preserve the membranous labyrinth during the procedure.
Main Results:
- Preoperative air-conduction thresholds (ACTs) were approximately 9-10 dB, with bone-conduction thresholds around 2.9-4.5 dB.
- Post-fenestration ACTs significantly increased to 41-42.2 dB (p < 0.01), while bone-conduction thresholds remained low (1.1-4.3 dB).
- The substantial elevation in ACTs indicates a significant decrease in hearing sensitivity to air-conducted sound.
Conclusions:
- A cochlear third window in the scala vestibuli demonstrably impairs hearing sensitivity to air-conducted sound.
- These experimental results align with theoretical models and clinical observations of third window conditions.
- The fat sand rat serves as a viable animal model for studying cochlear third window effects.
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