Ben I. Nageris, MD, Joseph Attias, DSC, and Michal Preis, MD contributed equally to this work as first authors.
A third window of the posterior semicircular canal: An animal model†
Article first published online: 26 JAN 2010
Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc.
Volume 120, Issue 5, pages 1034–1037, May 2010
How to Cite
Nageris, B. I., Attias, J., Shemesh, R., Hadar, T. and Preis, M. (2010), A third window of the posterior semicircular canal: An animal model. The Laryngoscope, 120: 1034–1037. doi: 10.1002/lary.20831
The authors have no funding, financial relationships, or conflicts of interest to disclose.
- Issue published online: 21 APR 2010
- Article first published online: 26 JAN 2010
- Accepted manuscript online: 26 JAN 2010 12:00AM EST
- Manuscript Accepted: 3 DEC 2009
- Vestibular window;
- third window;
- animal model;
- posterior canal dehiscence;
- Level of Evidence: 2c.
A third window in the vestibular apparatus has been investigated in both animals and humans, specifically in superior semicircular canal dehiscence. There are as yet no animal model studies of the effect of a third vestibular window of the posterior semicircular canal.
Original basic research study.
A fenestration was drilled in the bony labyrinth over the posterior semicircular canal, preserving the membranous labyrinth, in seven healthy, 6-month-old, fat sand rats (total 10 ears). Auditory brain stem responses to low- and high-frequency acoustic stimuli delivered by air conduction and bone conduction were recorded before and after fenestration.
On the preoperative auditory brainstem recordings, air-conduction thresholds to clicks and tone bursts averaged, respectively, 6.5 dB and 7.5 dB, and bone-conduction thresholds, 8 dB and 4.5 dB. Postoperatively, air-conduction thresholds averaged 14.5 dB, and bone-conduction thresholds 10.5 dB and 5 dB. The change in air-conduction thresholds was statistically significant (P < .01), whereas the bone conduction thresholds remained unchanged.
A vestibular third window in the posterior semicircular canal decreases the sensitivity to air-conducted sound stimuli, raising the air-conduction threshold. There is no change in the bone-conduction threshold. These findings agree with the theoretical model and clinical findings. Laryngoscope, 2010