Brain stem auditory-evoked response in the nonanesthetized horse and pony.
Abstract: The brain stem auditory-evoked response (BAER) was measured in 10 horses and 7 ponies under conditions suitable for clinical diagnostic testing. Latencies of 5 vertex-positive peaks and interpeak latency and amplitude ratio on the 1st and 4th peaks were determined. Data from horses and ponies were analyzed separately and were compared. The stimulus was a click (n = 3,000) ranging from 10- to 90-dB hearing level (HL). Neither horses nor ponies responded with a BAER at 10 dB nor did they give reliable responses at less than 50 dB. The 2nd of the BAER waves appeared in the record at lower stimulus intensities than did the 1st wave for the horse and pony. Horses and ponies had a decreasing latency for all waves, as a result of increasing stimulus intensity. Latencies were shorter for the ponies than for the horses at all stimulus intensities for the 1st, 2nd, 3rd, and 4th waves, but not the 5th wave. At 60-dB HL, the mean latencies for the 1st through 5th wave, respectively, for the horse were 1.73, 3.08, 3.93, 4.98, and 6.00 ms and for the pony 1.48, 2.73, 3.50, 4.56, and 6.58 ms. Interpeak latencies, 1st to 4th wave, averaged 3.22 ms (horse) and 3.11 ms (pony) for all stimulus intensities from 50- to 90-dB HL and had a tendency to decrease slightly as stimulus intensity increased. Amplitude ratios (4th wave/1st wave) were less than 1 for all stimulus intensities in the horse. In the pony, the ratio was less than 1 at greater than or equal to 70-dB HL and greater than 1 at less than or equal to 60-dB HL.
Publication Date: 1985-07-01 PubMed ID: 4026024
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- Journal Article
Summary
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The research examined the brain stem auditory-evoked response (BAER) under clinical diagnostic conditions in horses and ponies. It showed variations in amplitude ratio and latency duration based on the stimulus intensity and the species.
Methodology
- The researchers measured the brain stem auditory-evoked response (BAER), a test for hearing and brainstem function, in 10 horses and 7 ponies.
- The animals were tested under conditions mimicking those of clinical diagnostic testing, meaning they were not anesthetized and were exposed to various noise intensity levels.
- The stimulus used was a click sound played 3,000 times at intensities that varied from 10 to 90 decibels (dB) Hear Level (HL).
Findings
- None of the horses or ponies gave a BAER at a stimulus intensity of 10 dB, indicating that this was too low to elicit a response.
- Standard responses also weren’t seen at less than 50 dB, suggesting a higher intensity is required for reliable results.
- Through increased stimulus intensity, latencies (the times taken for a signal to reach the brain) of all waves decreased for both horses and ponies. This shows that louder noises get processed more quickly.
- Latencies were shorter for ponies than horses for the first four waves but not the fifth, showing audiological differences between the species.
- The mean latencies for the five waves in horses and ponies varied, with ponies generally having faster response times.
Interpeak Latencies and Amplitude Ratios
- Interpeak latency, the delay between waves, slightly decreased as stimulus intensity increased. Interpretation of this necessitates further research.
- Amplitude ratios (the size of the 4th wave response divided by the size of the 1st wave response) were less than 1 at all stimulus intensities in the horse. This shows the response was weaker in the later wave and may reflect differences in auditory processing or stimuli perception in horses.
- In ponies, the amplitude ratio was less than 1 for higher intensities (greater than or equal to 70-dB HL) but more than 1 at lower ones (less than or equal to 60-dB HL), meaning their response changed depending on the loudness of the noise.
Cite This Article
APA
Marshall AE.
(1985).
Brain stem auditory-evoked response in the nonanesthetized horse and pony.
Am J Vet Res, 46(7), 1445-1450.
Publication
Researcher Affiliations
MeSH Terms
- Animals
- Brain Stem / physiology
- Electrodes / veterinary
- Evoked Potentials, Auditory
- Female
- Hearing Disorders / diagnosis
- Hearing Disorders / veterinary
- Hearing Tests
- Horse Diseases / diagnosis
- Horses / physiology
- Male
- Reaction Time
- Reference Values
Citations
This article has been cited 8 times.- Wiśniewska A, Janczarek I, Ryżak M, Tkaczyk E, Kędzierski W. Behavioural responses of Konik Polski horses to natural, familiar sound of thunderstorm, and unfamiliar similar-sounding sounds of volcanic eruption and sea storms. BMC Vet Res 2022 May 30;18(1):207.
- Aleman M, Madigan JE, Williams DC, Holliday TA. Brainstem auditory evoked responses in an equine patient population. Part II: foals. J Vet Intern Med 2014 Jul-Aug;28(4):1318-24.
- Aleman M, Holliday TA, Nieto JE, Williams DC. Brainstem auditory evoked responses in an equine patient population: part I--adult horses. J Vet Intern Med 2014 Jul-Aug;28(4):1310-7.
- Webb AA. Brainstem auditory evoked response (BAER) testing in animals. Can Vet J 2009 Mar;50(3):313-8.
- Arai S. Brainstem auditory evoked potentials in cattle sedated with xylazine. Can J Vet Res 2008 Apr;72(3):287-90.
- Harland MM, Stewart AJ, Marshall AE, Belknap EB. Diagnosis of deafness in a horse by brainstem auditory evoked potential. Can Vet J 2006 Feb;47(2):151-4.
- Steiss JE. A survey of current techniques in veterinary electrodiagnostics: EEG, spinal evoked and brainstem auditory evoked potential recording. Vet Res Commun 1988;12(4-5):281-8.
- Olkowski AA, Gooneratne SR, Crichlow EC, Rousseaux CG, Christensen DA. Effects of high dietary sulfur on brain functions using evoked potentials technique. Can J Vet Res 1990 Jan;54(1):113-8.
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