Brainstem Auditory-Evoked Responses in Horses with Temporohyoid Osteoarthropathy
Article first published online: 4 AUG 2008
Copyright © 2008 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 22, Issue 5, pages 1196–1202, September–October 2008
How to Cite
Aleman, M., Puchalski, S.M., Williams, D.C., Kass, P.H. and Holliday, T.A. (2008), Brainstem Auditory-Evoked Responses in Horses with Temporohyoid Osteoarthropathy. Journal of Veterinary Internal Medicine, 22: 1196–1202. doi: 10.1111/j.1939-1676.2008.0158.x
- Issue published online: 25 AUG 2008
- Article first published online: 4 AUG 2008
- Submitted January 10, 2008; Revised March 25, 2008; Accepted June 13, 2008.
Background: Facial and vestibulocochlear nerve dysfunction occurs commonly in horses with temporohyoid osteoarthropathy (THO); however, auditory dysfunction has not been thoroughly assessed.
Objective: To determine if auditory abnormalities occur in horses with THO.
Animals: Eleven diseased and 8 control horses.
Methods: This is a prospective study in which brainstem auditory-evoked responses (BAER) were recorded in 11 horses diagnosed with THO through neurologic, endoscopic, radiographic, or computed tomographic examinations. BAER findings were compared with those recorded from 8 adult control horses.
Results: All horses with THO were found to have BAER abnormalities that included complete unilateral BAER loss (82%, n = 9/11), partial unilateral BAER loss (18%, n = 2/11) on the most affected side, and contralateral partial BAER loss (46%, n = 5/11). Nine horses had bilateral THO based on diagnostic imaging findings; of these, 5 (56%) horses also had bilateral BAER abnormalities. The complete absence of BAER in affected horses was most consistent with peripheral sensorineural hearing loss. There was a significant association between complete BAER loss and neurologic and diagnostic abnormalities.
Conclusions and Clinical Importance: Auditory abnormalities such as complete or partial BAER loss are common in horses with THO. The BAER test is an objective diagnostic tool that can aid along with other diagnostic modalities in the assessment, management, and follow-up of horses with THO. Furthermore, BAER studies may help to elucidate the pathophysiology of THO in horses.