CS: Wobbly Animals Flashcards
Ddx for a hyperacute onset, non progressive, strongly lateralised, non painful T3-L3 myelopathy
- non-painful -> in SC
- Non-progressive ->
> infarct (FCE) aetiology unknown or
> HVLD non-compressive nucleus pulposus EXTRUSION (not the same as IVDD)
What is a HVLD ?
- high velocity low volume??
- acute non-compressive nucleus pulposus extrusion
- > contusion but not compression
- sometimes painful
Tx and prog for HVLD?
Good, tx not surgical just physio and hydrotherapy
Do infarcts of the SC appear hypo or hyperintense?
Hyper
What are the 2 potential stages of pathology wrt IVDD?
- initial contusive injury
+- 2* ompressive injury if material hangs around
Where does a 2 engie gait indicate the lesion to be?
C6-T2
What is cervical spondylomyopathy?
= wobblers (covers many disease processes!!)
> 2 distinct types
- disk assocaited (multiple sites so hard to dx)
- osseus associated (cranial)
How is a hemivertebra defined?
> 25* angle of kyphosis
What is a flare up of a chronic disease termed?
Acute on chronic presentation
What may cause acute on chronic presentation of CVM/s?
Trauma can exacerbate underlying deformity
Diagnostic techniques for IVDD in the dog?
> survey spinal rads (suggestive but not dx)
myelography (cord compression and malacia)
CT (fat v soft tissue, can seee extruded mineralised disk material)
MRI (T2W)
CSF analysis
What an be seen on rads with IVDD?
- narrowed intervertebral space
- altered shape of intervertebral foramina
- radiopaque material in the vertebral canal [with chondroid type 1 dz]/superimposed on foramen
- v size dorsal articular joint space
- spondylosis deformans
- sclerosis of end plates
- do NOT necessarily correlate with clinical significance or spine/n. compression
What can myelography be useful for?
- ID siteo f cord compression
- myelomalacia
What is CT useful for with IVDD?
- fat v soft tissue
- can kind of see extruded dsik material if mineralised
What may be seen on MRI with IVDD?
> T2W
- normal hydrated nucleus pulposus is hyperintense cf. annulus fibrosus
- becoems iso/hypointense as loses hydration
- extrusion of degenerate nucleus pulposus appears as hypoinense extradural SC compression
Is degreee of compression of the SC correlated to prognosis?
NO - presence of deep pain only prognostic indicator
What CSF changes can be seen with IVDD?
- caudal to lesion ^ protein conc
+- pleiocytoisis w/ predominance of LYMPHOCYTES if examined >7d after onset
What is spondylosis deformans?
LOOK UP
MEdical conservative tx of IVDD? When is this indicated? What is the “hope” with medical management?
> decision based on severity of clinical signs (milkdly affected = pain alone/mild paresis)
- only suggest if VERY SURE it is IVDD and nothing more sinister!
- disk isease v. rare >10yo so more indepth work up needed for these
hope that compressive material will dissipate and dorsal annulus will heal over and not re-herniate
Tx
- cage confinement min 2 weeks (4-6 better)
- >2 weeks no improvement - consider surgery
- if improvement seen continue cage rest 1-2 weeks after clinical resolution
- gentle physio ad short lead walks
corticosteroids NOT indicated despite advice you might hear.
Surgical tx of IVDD? Whaen is this indicated?
> indicated if unable to supportt weight
Aim: surgical decompression of SC (if retain deep pain before surgery 90% chance of walking after surgery aim to carry out
How long after surgery does a lack of deep pain indicate v poor prognosis?
2-4 weeks
Pathogenesis of EHV myelopathy?
- endotheliotropic virus
- vasculitis
- local areas of BBB break down
- protein and pigment, then cells leak into CSF (pleiocytosis)
Which diagnostic tests are useful for dx of CVM/S?
> neuro exam
- sway test for paresis (@walk)
- slap test (withers-larynx) crude
radiology
- plain lateral rads (transverse processes must be lined up for a tru lateral!!) @C1-C2, C3-C5, C6-C7
- measure inter/intravertebral ratios
- ski ramping (caudal epiphyseal flare)
- caudal extension of dorsa llamina
- step
- subluxation
contrast myelography to prove compression
- GA and recumbency required so referral only
- neutral, flex and extension radiographs to ID dynamic compression
- always necessary if contemplating surgery
CSF
- normal with CVM/S
- can r/o other dx
experimental endoscopy/myeloscopy of arachnoid space (between dura and pia)
Outline hwo to calculate intra- and intervertebral ratios. WHat clinical significance are these?
a= minimum width of vertebral canal b= minimum distance from physis to preceding dorsal bit of spine c= ??? A= maximum width of vertebral physis B= max width of next vertebra along caudally > Intervertebral = b/B or c/B > Intravertebral = a/A - If intRAvertebral ratio
How may presence of bog spavin be linked to myelopathies?
- Bog spavin OCD -> 2* OA
- link between presence of OCD in hocks and other joints
- so presence of bog spavin -> ^ risk OCD in neck joints
Aetiology of CVM/S?
- developmental condition of well fed foals, esp TB colts
- ? genetic: OCD lesions seen on articular surfces and vertebral body growth plates
- often biggest, strongest foal - fed more to encourage growth
- abnormalities of vertebral bodies, dorsal laminae and/or articular processes
- dynamic and static stenosis of vertebral canal and focal compression of the SC
What are the 2 types of CVM/S?
> type 1 (dynamic)
- usually C2- C6
- epiphyseal flaring -> narrowing @ cranio/caudal orifices
type 2 (static)
- usually C5-C7
- dmaage ascending [-> ataxia] and descending [-> paresis] tracts
Potential anagement/tx of CVM/S?
> conservative (more successful for dynamic)
- v growth rate (Pace diet)
- 6mo box rest (prone to accidents)
- adjust Ca/Ph ration
- feedd/waer elevated
- articular process joint mediccation (u/s guidance; not useful for ataxia but good for neck pain)
surgical
- drill out intervertebral space, screw to arthrodese the vertebrae in extension
- success depends on duration of clinical signs, severity and age (young horses tx early = greatest success)
- cervical fusion to immobilise affected vertebral spaces -> regression of enlarged intervertebral joints and decompression
Prognosis of CVM/S?
- guarded for return to usfulness (1/2 return to work) have to wait min 6 months post op to evaluate
- suitable for breeding
- prog worse for static
Safety implications for horses with CVM/S?
- always say ride at your own risk!!
- Grade 2 or worse ataxia = dont ride
- Grade 1 ataxia = probably ok, such a subjective scale anyway
> older horses more guarded prognosis
What breeds of dog are pdf IVDD?
- chondrodystrophic breeds
- butt all dogs can get it !! inc large breed
> young - middle age commonly, not necessarily ^ risk with age
