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This work was supported by the National Science Council (grant no. NSC 97-2314-B002-094-MY3) and National Taiwan University Hospital (no. NTUH97-M-1009), Taipei, Taiwan. The authors have no other funding, financial relationships, or conflicts of interest to disclose.
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Otology
A novel inner ear monitoring system for evaluating ototoxicity of gentamicin eardrops in guinea pigs†
Article first published online: 12 MAY 2010
DOI: 10.1002/lary.20923
Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc.
Additional Information
How to Cite
Yang, T.-H., Liu, S.-H. and Young, Y.-H. (2010), A novel inner ear monitoring system for evaluating ototoxicity of gentamicin eardrops in guinea pigs. The Laryngoscope, 120: 1220–1226. doi: 10.1002/lary.20923
- †
Publication History
- Issue published online: 21 MAY 2010
- Article first published online: 12 MAY 2010
- Manuscript Accepted: 2 MAR 2010
- Manuscript Revised: 24 FEB 2010
- Manuscript Received: 21 JAN 2010
Funded by
- National Science Council. Grant Number: NSC 97-2314-B002-094-MY3
- National Taiwan University Hospital. Grant Number: NTUH97-M-1009
- Abstract
- Article
- References
- Cited By
Keywords:
- Eardrops;
- gentamicin;
- ototoxicity;
- cervical vestibular-evoked myogenic potential;
- ocular vestibular-evoked myogenic potential;
- Level of Evidence: 2c.
Abstract
Objective/Hypothesis:
Although most studies have identified damage in the cochlea and semicircular canals as the primary sites of aminoglycoside toxicity, little attention has been devoted to the toxic effects on the otolithic organs. This study aimed to assess the toxic effect of gentamicin eardrops on the inner ear end organs via a novel inner ear monitoring system combined with morphological examination.
Study Design:
Prospective study.
Methods:
Guinea pigs were treated with 50 μL saline (n = 10) and 50 μL gentamicin (40 mg/mL; n = 10) on the right and left round window membranes, respectively. An inner ear monitoring system, including auditory brainstem response (ABR), caloric, ocular vestibular-evoked myogenic potential (oVEMP), and cervical VEMP (cVEMP) tests, was used to assess ototoxicity in guinea pigs at 2 weeks after treatment. The animals were then sacrificed for morphological study via confocal microscopy.
Results:
Normal results in ABR, caloric, cVEMP, and oVEMP tests were shown in all saline-treated ears, whereas elevated ABR threshold and absent responses in caloric, oVEMP, and cVEMP tests were noted in all gentamicin-treated ears. The cochlear and vestibular explants harvested from the gentamicin-treated ears revealed substantial loss of hair cells.
Conclusions:
The inner ear monitoring system, including ABR, caloric, oVEMP, and cVEMP tests, might help to evaluate toxicity information of the topical eardrops or agents on the inner ear end organs, including cochlea, semicircular canals, utricle, and saccule.