Difference between revisions of "Laryngeal Hemiplegia"
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(Created page with "*In Horses: *Unilateral paralysis of arytenoids *Common 2-13% training thoroughbreds *Damaged/ dysfunctional recurrent laryngel nerve (branch of vagus) *Mostly left side affected...") |
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**Neoplasia | **Neoplasia | ||
**Trauma | **Trauma | ||
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| + | * These horses are also known as "'''roarers'''" | ||
| + | * Equine laryngeal hemiplegia is a very common condition. | ||
| + | |||
| + | ===Pathogenesis=== | ||
| + | |||
| + | # The disease starts with an idiopathic degeneration of the left recurrent laryngeal nerve. | ||
| + | # This leads to atrophy of the left dorsal cricoarytenoid muscle. | ||
| + | # Without the use of this muscle, the horse is unable to abduct the left arytenoid cartilage and vocal fold. | ||
| + | # Airways are therefore partially obstructed on inspiration. | ||
| + | |||
| + | [http://w3.vet.cornell.edu/nst/nst.asp?Fun=F_KSsrch&kw=HEMIPLEGIA View images courtesy of Cornell Veterinary Medicine] | ||
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[[Category:Larynx - Pathology]] | [[Category:Larynx - Pathology]] | ||
[[Category:Respiratory System - Degenerative Pathology]] | [[Category:Respiratory System - Degenerative Pathology]] | ||
| + | [[Category:Respiratory Diseases - Horse]] | ||
| + | [[Category:Central Nervous System - Degenerative Pathology]] | ||
Revision as of 14:11, 8 March 2011
- In Horses:
- Unilateral paralysis of arytenoids
- Common 2-13% training thoroughbreds
- Damaged/ dysfunctional recurrent laryngel nerve (branch of vagus)
- Mostly left side affected, occasionally also the right nerve
- Demyelination of nerve fibres, and leading to atrophy of intrinsic laryngeal muscles particularly the adductor (cricoarytenoid) which allows the left arytenoid cartilage to lean into the laryngeal lumen
- The 'roaring' is noticeable after exercising
- The aetiology is not properly established but suggested factors are:
- Length of the left recurrent nerve
- Extension neuritis in guttural pouch mycosis
- Neurotoxins - organophosphorus compounds may produce similar degenerative changes in the nerves
- Enlarged retropharyngeal lymph nodes
- Neoplasia
- Trauma
- These horses are also known as "roarers"
- Equine laryngeal hemiplegia is a very common condition.
Pathogenesis
- The disease starts with an idiopathic degeneration of the left recurrent laryngeal nerve.
- This leads to atrophy of the left dorsal cricoarytenoid muscle.
- Without the use of this muscle, the horse is unable to abduct the left arytenoid cartilage and vocal fold.
- Airways are therefore partially obstructed on inspiration.
View images courtesy of Cornell Veterinary Medicine