Stridor 2/14/17 Dr. Yvorchuck Flashcards
What is ILH
Left laryngeal hemiplegia
word association:
Left Laryngeal Hemiplegia > nerve?
Left recurrent laryngeal n.
word association:
Left Laryngeal Hemiplegia > involvement
Cricoarytenoid dorsalis mm. (CAD)
atrophy of the CAD m. on left side
word association:
ILH > what type of -pathy
axonopathy
word association:
ILH > tx of
“tie back” or laryngoplasty
ILH pathophysiology
correlation between axon density & CAD m. volume > correlation between CAD m. volume & dysfunction (grade of LH)
distal axonopathy of RLN
large horses -> long necks
repetitive trauma (think drafts & collar worn while pulling)
trauma from othr sources (think venipuncture gone wrong)
Non-ILH pathophysiology
(Right or Bilateral Laryngeal Hemiplegia)
consider as manifestation of generalaized or localized neurologic dysfunction
- perivascular injections
- Guttural pouch dz
- dz of neck & cranial thorax
ILH CS
exercise intolerance
INSPIRATORY noise = “roar”
possible EIPH
Finish the sentence:
Good to remember when you change the mechanics in respiratory tract…
you can have several dz occur together!
Not unusual to see DDSP + EIPH, DDSP + ILH, DDSP + EIPH + ILH
what 2 dz won’t you see together
ILH developing subsequent to EE or vice versa
they have nothing to do with each other (mechanically speaking!)
T or F
It is possible for an animal to present for a noise & not exercise intolerance
True
If it not working at a level that requires the full respiratory capacity there might not be a performance issue
ILH dx
CS & Hx
ENDOSCOPY (may require treadmill eval)
EXTERNAL ULTRASOUND
external laryngeal palpation (feel for asymmetry)
describe how to tell which side is affected
when the arytenoid m. is atrophied the arytenoid will be position more axial
draw line straight down from center and see which side is smaller width -> affected side!
what is grading system for laryngeal function (not grading laryngeal hemiplegia)
Grade 1 - Normal
Grade 2 - Asynchronous movement/ full abduction
Grade 3 - asynchronous movement/ incomplete abduction
Grade 4 - complete paralysis
since the grading system is at rest, when do you need endoscopy at exercise?
if a horse has a Grade 3!
- there are subgroups of grade 3s the important one is the Grade 3 that at exercise is: asynchronous. but abducts fully, and stays abducted - in that case even though the animal has LH that is probably not the cause of exercise intolerance!*
- the other type is the one that initially abducts fully (still asynchronous) but then fatiques and does not (turning into an obstruction).*
LH Tx
Determine Goal &/or presenting complaint (e.g. noise)
possible ventriculochordectomy alone (just correcting noise)
in drafts often done bilaterally as standing sx
To reestablish airway mechanics = Sx
LARYNGOPLASTY (“tie back”)
bilateral VENTRICULOCHORDECTOMY
occasionally - arythenoidectomy
why would you want to do a standing ventriculochordectomy in a draft horse
concerns about post anesthetic myopathy (with GA)
what is your dx
EE
