Myelopathies pt 2 Flashcards
types of spinal trauma
- Endogenous
e.g. IVD extrusion
<><> - EXOGENOUS (e.g. hit by car)
Spinal cord contusion
Vertebral fracture / luxation
Traumatic IVDH extrusion
Hemorrhage
Spinal trauma: Initial management
Trauma patient: Life-threatening injuries?!
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1. ABC
2.
a) Minimal manipulation, immobilization
b) Physical, orthopedic examinations
c) Brief neurologic examination
Lateral recumbence
Localize, severity
Deep pain
Spinal trauma: Diagnosis
Bloodwork / Thoracic Rx /Abdominal Ux
Spinal radiographs: Whole spine
Myelogram, CT, CT-myelogram, MRI
Spinal trauma:Treatment
- for primary vs secondary injuries
many techniques, surgeon preference
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Primary injury
◦ Decompression
◦ Stabilization
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Secondary injury
◦ Maintenance spinal cord perfusion (BP, PO2)
> bloodflow reqs of CNS are very high
> at least keep on fluids
◦ Steroids???…controversial
radiographs or myelogram for FCEM diagnosis?
useless, basically
common causes of chronic myelopathies
IVDH: protrusion
Atlantoaxial subluxation
Degenerative myelopathy
Caudal cervical spondylomyelopathy
Degenerative lumbosacral stenosis
IVDH: protrusion
- pathogenesis, progression
Fibroid degeneration of the intact disc
> HANSEN TYPE II DEGENERATION
> Normal aging process
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Progressive thickening dorsal annulus
Chronic, slow compressive myelopathy
IVDH protrusion:
- clinical signs?
- who gets this?
- where anatomincally?
Chronic, progressive (weeks-years)
Non-chondrodystrophic large dogs:
◦ German Shepherd, Retrievers… > most common reason for older german shepherds to have trouble walking
◦ But happens in any canine breed (even cats)
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Age: > 5 year-old (5-12y)
Cervical vs thoracolumbar
Spinal pain: mild/moderate vs none
IVDH protrusion: diagnosis
- Myelogram
- CT-myelogram
- MRI
<><> - radiograph alone totally useless, need something beyond that
IVD protrusion: Treatment options, success rate
Conservative:
Restricted activity
Anti-inflammatory drugs: STEROIDS:
> They actually work for this! totally different pathophysiology
> Useful for chronic spinal cord injury
> Prednisone
Many controlled long time
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Surgical:
Lower success than acute IVDH (guarded prognosis)
> can be mulitple sites - which is most significant? where do we cut?
> tend to use conservative treatment more here
Atlantoaxial subluxation - what is this? forms
Instability between C1-C2
Dorsal displacement C2
◦ Spinal cord compression
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Forms:
◦ Congenital
◦ Acquired (trauma)
Atlantoaxial subluxation common congenital causes:
- fractured dens
- aplastic or absent dens
- deviated dens
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> dorsal atlantoaxial ligament will snap. C1 can compress brainstem.
Atlantoaxial subluxation Clinical signs
C1-C5 myelopathy
Chronic vs acute
Progressive
Severe neck pain
Dyspnea
Atlantoaxial subluxation - who gets the congential form? why? what about acquired?
Congenital:
Small-toy canine breeds (Yorkshire terrier, Chihuahua, Miniature Schnauzer…)
Usually < 1 year-old
Failure ligament support or C2 dens development (hypoplasia/aplasia, dorsal angulation)
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Acquired:
Trauma in any dog and cat, acute onset
Atlantoaxial subluxation - diagnosis, considerations
Spinal radiographs:
◦ Usually diagnostic
◦ Increased space dorsal lamina atlas – dorsal spinous process axis (C2)
◦ Extreme care manipulation
◦ Better if awake patient
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Myelogram, CT, MRI: if needed
Atlantoaxial subluxation Surgical treatment, risks
Stabilization ± dens removal
High morbidity / mortality
Risk respiratory arrest and death
Atlantoaxial subluxation conservative treatments, who they are for, complications
Young animals with mild signs
External splint ≥ 6 weeks
Risk of recurrences
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we try this before going to surgery - at the end of the day, if it is a congenital issue, chances of a recurrence are quite high
Degenerative myelopathy - what is this? pathogenesis?
Degeneration spinal cord white matter
Mainly T3-L3
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Pathogenesis:
Genetic
* Form of amyotrophic lateral sclerosis (ALS)
* Genetic marker identified
Degenerative myelopathy Signalment
Mainly large-breed dogs:
German Shepherd
Boxer
Pembrokeshire Welsh Corgi
Others
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Age:
> 5 year-old (mean: 9y)
> chronic, slow process
Degenerative myelopathy Clinical signs
Chronic, progressive
T3-L3
◦ Severe PL proprioceptive ataxia
◦ Paraparesis to Paraplegia (6-12m)
◦ Sometimes: decreased patellar reflexes (L4-L6 nerve roots)
No spinal pain
Degenerative myelopathy diagnosis
Rule-out other chronic T3-L3 myelopathies
IVD protrusion, neoplasia…
Normal spinal imaging
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Genetic marker (DNA test)
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Definitive diagnosis: Histopathology
Degenerative myelopathy treatment, prognosis
Supportive
Physical therapy
Vitamins, aminocaproic ac, steroids? > Not proved efficacy.
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Prognosis:
Poor
Euthanasia 6-12m
Can progress to thoracic limbs if kept alive
what is Wobbler’s syndrome?
Caudal cervical spondylomyelopathy (CCSM)
- cervical stenotic myelopathy, cervical malformation/malarticulation…
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- Vertebral malformations / malarticulation affecting caudal cervical vertebrae and associated structures (ligaments, articular facets, intervertebral discs):
> Progressive vertebral canal stenosis and compressive cervical myelopathy
CCSM: Forms
- who gets them? pathogenesis?
- Disc-associated CCSM:
Large-breed dogs: Doberman
Middle aged-older (3-9 year-old)
IVD protrusion
<><><><> - Osseous-associated CCSM:
Giant-breed dogs: Great Dane
< 3 year-old
Articular facets DJD/hypertrophy, synovial cysts, vertebral canal stenosis
> bone is enlarged, and is compressing the spinal cord (articular facets)
CCSM: Clinical signs
Chronic, progressive
C6-T2 > C1-C5
Tetraparesis
◦ Pelvic limbs much worse
◦ Pelvic limbs: Severe ataxia and paresis
◦ Thoracic limbs: Short, stilted, choppy gait (hypometria)
Neck pain (50% cases)
CCSM: Diagnosis
Spinal radiographs
Myelogram
CT-myelogram
MRI > Identifies intramedullary lesions
CCSM: Treatment options
Conservative therapy:
◦ Restricted exercise, physical therapy, anti-inflammatory (steroids)
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Surgical therapy:
* Ventral approach
> Ventral slot ± stabilization
> Disc-associated form
* Dorsal approach
> Dorsal laminectomy
> Osseous-associated form
CCSM: Prognosis
Long recovery period
Surgical treatment:
> Good prognosis on short-term but high recurrence rate on long-term
“Domino effect” (surgical stabilization)
> stabilize one area and its gets better, but gradually other areas may get worse
Degenerative lumbosacral stenosis (DLSS)
- what is this?
Compression cauda equina nerve roots due to degenerative changes at L7-S1
Cauda equina syndrome, lumbosacral malarticulation / malformation, lumbosacral instability, lumbosacral spondylopathy…
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- nerve roots as opposed to spinal cord - nreve roots can tolerate compression much better
- this compression will not result in the same clinical signs and consequences that we will see in other areas
DLSS: Pathogenesis
Chronic instability?
IVD protusion L7-S1
Hypertrophy:
> Ligaments (interarcuate-flavum)
> Articular facets (DJD, synovial cysts)
Subluxation L7-S1
DLSS: Signalment
- Large-breed dogs > German Shepherd
- Age: Middle-aged to older
- Males > females?
DLSS: Clinical signs, presentation
LUMBOSACRAL PAIN
Reluctance to rise, sit, jump…
Lameness
PLs tucked under abdomen
Low tail carriage
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Other clinical signs often not present
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Detection LS pain:
> Dorsal palpation LS joint, hyperextension PLs, raising up tail, rectal palpation LS joint
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LMN lesion caudal to L7 (sciatic, pudendal, coccygeal)
Paraparesis (short-stride gait, not ataxia or mild)
Mild proprioceptive deficits PLs
Tail paralysis (low tail carriage)
PLs muscle atrophy (sciatic innervated)
Decreased withdrawal reflexes (hock)
Urinary / fecal incontinence
Paraesthesias (tail, feet, rump biting)
DLSS: Diagnosis
Spinal radiographs, myelogram (but spinal cord ends at L6 in large dogs), CT, epidurography, discography
MRI
DLSS:Treatment options, success rate
Conservative
◦ First episode / intermittent pain
◦ Restricted exercise
◦ Anti-inflammatory
◦ Success: ≈ 55%
<><><><>
Surgical
◦ Dorsal laminectomy L7-S1
◦ ± stabilization L7-S1
◦ Success: 70% ?
DLSS: Prognosis
Surgery requires ≥12 weeks confinement
Recurrences: More likely in active-working dogs
Only pain: Good-Excellent
Motor deficits: Good-Guarded
Incontinence: guarded-POOR
