Term
| What are the two types of intervertebral disk dz? |
|
Definition
-Hansen Type I: intervertebral disk herniation
-Hansen Type II: intervertebral disk protrusion |
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Term
| What are the components of the intervertebral disk? |
|
Definition
-annulus fibrosus: outer portion made up of rings of lamellae that is thicker ventrally
-nucleus pulposus: centrally & slightly dorsally (eccentric) |
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Term
| Why are the cartilagenous vertebral end plates important? |
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Definition
| -source of nutrients for intervertebral disk via diffusion |
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Term
| What is the function of the intervertebral disk? What determines its ability to do this? |
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Definition
-shock absorption & distribution
-determined by proteoglycans in nucleus & elasticity of the annulus |
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Term
| What causes intervertebral disk herniation from a physiologic stand point? |
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Definition
-aka chondroid metaplasia
-loss of water content + deposition of mineral + alteration of proteoglycans = less compliant disc = intradiscal pressure inc |
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Term
| How do the proteoglycans change w/ chondroid metaplasia? |
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Definition
| -chondroitin sulfate becomes keratin sulfate |
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Term
| What is the typical signalment of intervertebral disk herniation (chondroid metaplasia)? |
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Definition
-chondrodystrophic breeds: Dachshund
-3-5y = TL
-8-12y = cervical spinal cord |
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Term
| How does intervertebral disk herniation present clinically? |
|
Definition
-compressive myelopathy
-contusion injury
-acute, progressive |
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Term
| Severity of intervertebral disk herniation depends on what factors? |
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Definition
-location of compression
-duration of compression
-velocity/force of herniation
-volume of disc herniation (nucleus material) |
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Term
| Describe the clinical sings in detail w/ intervertebral disk herniation. |
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Definition
-paraspinal hyperesthesia: abdominal discomfort, reluctance to ambulate, hunched back, guarded neck, vocalization, forelimb lameness (nerve root signature)
-ataxia/paresis
-paralysis (plegia) |
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Term
| What is the typical incidence of cervical intervertebral disk herniation? Common locations? CS more specific? |
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Definition
-25-33%
-C2-3 to C5-6
-pain alone more common |
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Term
| What is the typical incidence of thoracolumbar intervertebral disk herniation? Locations? CS more specific? |
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Definition
-66-75%
-T10-11 to L6-7
-pain AND NEURO DEFICITS |
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Term
| Why do we not get intervertebral disk herniation at T1-T9? |
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Definition
| -protected by intercapital ligament from rib heads |
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Term
| Why is thoracolumbar intervertebral disk herniation more commonly seen w/ neuro sings? |
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Definition
| -because cervical spinal cord has mroe room around spinal cord |
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Term
| Why would we take rads for intervertebral disk herniation? How accurate are they? What do you look for? |
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Definition
-rule out other differentials
-35% accurate
-look for foraminal changes/mineralization, narrowing/wedging of sick space, mineralized disk IN SITU |
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Term
| Why do we use caution if we ID a mineralized disk in situ in a suspected intervertebral disk herniation on rads? |
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Definition
-does not mean this is the issue if in its correct spot
-could just be an incidental finding |
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Term
| How do we actually diagnose intervertebral disk herniation? |
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Definition
-myelogram: really historical b/c causes seizurs but does allow CSF collection too
-CT
-MRI: best |
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Term
| When is medical management alone successful w/ intervertebral disk herniation? |
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Definition
-acute pain only: 90%
-ambulatory paresis: 90% |
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Term
| If intevertebral disk herniation is protracted pain only, what do we do? |
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Definition
| -poor w/ med, thus surgery (90%) |
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Term
| When are we stuck b/n medical management and surgical management? |
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Definition
-nonambulatory paresis: meds = 50% & sx = 90%
-plegia w/ deep pain: meds = 50% & sx = 90% |
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Term
| How do we handle an intervertebral disk herniation case w/ plegia w/out deep pain w/in the first 24 hrs? |
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Definition
| -meds is guarde dprognosis but sx is only 50-60% |
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Term
| How do we handle an intervertebral disk herniation case w/ plegia w/out deep pain in the frst 48 hrs? |
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Definition
| -grave med prognosis but sx < 5% |
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Term
| What are the goals of medical management w/ intervertebral disk herniation? |
|
Definition
-reduce inflammaiton
-disk resorption |
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Term
| How do we medically manage intervertebral disk herniation? |
|
Definition
-dec motion: crate rest 4w w/ leash walks for bathroom
-pain meds: Tramadol/NSAID +/- gabapentin |
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Term
| Which intervertebral disk herniation cases are managed medically? |
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Definition
-pain only
-ambulatory paresis |
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Term
| What are the goals of surgical management of intervertebral disk herniation? |
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Definition
-remove compression
-reduce inflammation/pain |
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Term
| Which intervertebral disk herniation cases are managed surgically? |
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Definition
-nonambulatory paresis
-plegia/paralysis |
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Term
| Which surgical procedures are used to surgically treat intervertebral disk herniation? Post op? |
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Definition
-ventral slot diskectomy: cerivcal
-hemilaminectomy: dorsal TL
-manage medically post-op for 4w |
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|
Term
| HOw common is intervertebral disk hernation recurrence? |
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Definition
-15-20%
-50% risk w/ >5 mineralized disks in SITU
-disk inc w/ inappropriate management |
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Term
| What is a percutaneous laser disk ablation (LDA) for intervertebral disk herniation? Why would we do it? |
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Definition
-approach to remove (ablate) the nucleus pulposus
-performed from T10-11 thru L4-5
-intended to reduce risk of recurrence: 4.5% |
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Term
| What is the other name for intervertebral disk protrusion? What happens physiologically? |
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Definition
-fibroid metaplasia
-dorsal annulus weakens and nucleus pulposus protrudes into the annulus |
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Term
| What are the resulting effects of itnervertebral disk protrusion? |
|
Definition
-ischemic myelopathy
-dec blood circulation
-demyelination/axonal degen
-SLOOOOOOOOW PROGRESSION OF MYELOPATHY |
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Term
| What is the typical signalment if intervertebral disk protrusion? |
|
Definition
-largebreed, non-chondrodystrophic: Labs
-middle-aged to older: 5-12y |
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Term
| What do we see clinically w/ intervertebral disk protrusion? Common locations? |
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Definition
-slow (ww-mm) progressive ataxia
-pain at site of protrusion
-TL >>> cervical |
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Term
| What are our big differentials for intervertebral disk protrusion? |
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Definition
-neoplasia
-degen myelopathy
-infeciton/inflammation
-musculoskeletal dz |
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Term
| How useful are rads for intervertebral disk protrusion? |
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Definition
| -only useful to rule out differentials b/c cannot ever be seen on rads |
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|
Term
| How do we diagnose intervertebral disk protrusion? |
|
Definition
|
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Term
| How do we treat interbertebral disk protrusion? |
|
Definition
-meds >> sx
-pain meds: Tramadol/NSAID +/- gabapentin
-nursing/supportive care: sling support, padded bedding, good fooring, bladder management |
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Term
| What are the goals of surgical management if intervertebral disk protrusion? |
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Definition
-decompression
-restoration of blood flow
-axonal regeneration |
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Term
| What sx procedure do we use for intervertebral disk protrusion? |
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Definition
|
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Term
| Why is medical management preferred for intervertebral disk protrusion over surgical? |
|
Definition
-acute worsening of neuro sings
-deterioration of signs w/in 1 year
continue medical management protocol |
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Term
| What is different about lumbosacral movement? |
|
Definition
-mainly flexion
-restricted degrees of lateral bending, rotation, extension |
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Term
| What are some degenerative causes of lumbosacral disease? |
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Definition
-disc protrusion
-ligamentum flavum degen
-dorsal longitudinal ligament hypertrophy
-articular facet hypertrophy
-spondylosis
-instability |
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Term
| What are some congenital lumbosaral diseases? |
|
Definition
-stenosis of canal
-malarticultion/malformation
-transitional vertebrae
-osteochondrosis of bertebral end plate |
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Term
| What is the typical signalment of lumbosacral disease? |
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Definition
-large-breed, middle-aged
-active working (GSD) |
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Term
| What are the clinical signs of lumbosacral disease? |
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Definition
-reluctance to jump
-less active
-stiff hindlimb gat
-low tail carriage
-urinar or fecal incontinence
-lower back pain/weakness due to vascular compromise and/or nerve root compression
-pain +/- neuro deficits |
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Term
| What are our major differenitals for lumbosacral dz? |
|
Definition
-neoplasia
-hip dysplasia
-degen myelopathy |
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Term
| How do we differentiate hip/leg pain & lumbosacral pain? |
|
Definition
-tail jack
-dorsal pressure on rectal
-lay down and pressure on hips |
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Term
| What is pseudohyperreflexia seen w/ lumbosacral dz? Explain it. |
|
Definition
-exaggerated patellar reflex
-lumbosacral dz often affects the sciatic n but spares the femoral n thus the lack of antagonistic muscle action makes patellar reflex look exaggerated |
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Term
| How do we diagnose lumbosacral dz? |
|
Definition
-rads: spondylosis, narrowed disc, endplate sclerosis, transitional vertebrae
-CT
-MRI |
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Term
| How do we medically treat lumbosacral dz? |
|
Definition
-pain meds: tramadol +/- gabapentin
-rest
-epidural steroid injections: only really works for pain, not neuro deficits
-appropriate bedding
-bladder control if needed |
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Term
| What are the goals of surgical treatment of lumbosacral dz? |
|
Definition
-decompression
-pain reliefe
-axonal regeneration |
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Term
| What are or options for surgically managing lumbosacral dz? |
|
Definition
-laminectomy + discectomy
-distraction & stabilization |
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Term
| What is the prognosis of laminectomy & discectomy w/ lumbosacral dz? |
|
Definition
|
|
Term
| What is the best surgical outcome w/ lumbosacral dz? |
|
Definition
-w/ mild dz
-50% success rate w/ severe neuro signs |
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Term
| What are the causes of recurrence of lumbosacral dz? |
|
Definition
-new bone formation
-scar tissue formation |
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|
Term
| What are some of the names for Wobbler Syndrome? |
|
Definition
-cervical spondylomyelopathy
-cervical vertebral instability
-cervical spondylopathy
-cervical malformation-malarticulation
-cervical spondylolisthesis |
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|
Term
|
Definition
| -cervical malformation => compression of spinal cord/nerve roots => pain/neuro signs |
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|
Term
| What are the different types of wobblers? |
|
Definition
-disc-assoc
-osseous-assoc compression |
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Term
| What is the typical signalment of disc-assoc Wobblers? Where does it occur? |
|
Definition
-middle-large breed: Dobies
-C5-6/6-7 |
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Term
| What actually happens w/ wobblers physiologically? |
|
Definition
-more torsion of caudal cervical spine leads to intervertebral disc protrusion
-you can also get ligamentum flavum hypertrophy |
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Term
| What is the typical signalment of osseous-assoc wobblers? |
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Definition
| -young giant breed: Great Dane |
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Term
| What actually happens w/ osseous-assoc wobblers? |
|
Definition
-ligamentum flavum hypertrophy
-vertebrall canal stenossi |
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Term
| What causes vertebral canal stenosis w/ osseous-assoc wobblers? |
|
Definition
-proliferation of vertebral arch
-articular process proliferation
-pedicle proliferation |
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Term
| What is the clinical presentation of Wobblers? |
|
Definition
-chronic, progressive: weeks to moths
-acute presentation: neck pain
-mild to mod: proprioceptive, deficits/ataxia, lameness |
|
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Term
| With a large breed signalment, is Wobblers more likely to be a single or multiple presentation? What is the most commonly affected location? |
|
Definition
-50% single site & 50% multiple site
-C6-7 |
|
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Term
| Is Wobblers more likely to be single site or multiple site w/ giant breed signalment? Which site is most commonly affected? |
|
Definition
-20% single site & 80% multiple sites
-C6-7 most common |
|
|
Term
| How do we diagnose Wobblers? |
|
Definition
-rads
-CT: see compression
-MRI: gold standard: see spinal cord parenchyma |
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|
Term
| How do we medically treat wobblers? |
|
Definition
-RESERVED FOR MILD CASES
-exercise restriction
-harness instead of leash
-pain meds: NSAIDs or steroids
-good footing, padded bedding |
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|
Term
| What is the rate of success w/ medical management of Wobblers? |
|
Definition
-54% improved
-27% unchanged neurologcally
-CS improved or stable 1% |
|
|
Term
| What are the indications for surgical treatment? |
|
Definition
-more severe neuro signs and pain
-lack of response to medical management
-short and long-term expectations of owner
-presence of concurrent problems |
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|
Term
| What is the rate of success w/ surgical treatment of Wobblers? |
|
Definition
| -improvement of 81% of cases |
|
|
Term
| What is our surgical technique for static lesions causing Wobblers? |
|
Definition
| -direct decompression: ventral slot, dorsal laminectomy |
|
|
Term
| What is our surgical technique for dynamic lesions causing Wobblers? |
|
Definition
| -distraction, stabilization: decompress disc protrusion, stabilize disc space w/ spacer/implants |
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|
Term
| What is the liklihood of neuro deterioration after Wobblers dz? |
|
Definition
| -most significant with a continuous laminectomy (70%) |
|
|
Term
| What is a domino effect w/ Wobblers? |
|
Definition
-adjacent segment syndrome (20%) mainly occuring w/ distracton techniques
-altered biomechanis at operated site leads to stress/load at adjacent site |
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|
Term
| What is the general prognosis w/ Wobblers? |
|
Definition
-up to 80% improvement
-risk of recurrence: 25% |
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|
Term
| What is atlantoaxial instability? |
|
Definition
| -cranial displacement of axis in relation to atlas into the spinal cord causing compression/concussion of cranial cervical spinal cord |
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|
Term
| What causes atlantoaxial instability? |
|
Definition
-ligamentous instability
-osseous abnormalitie |
|
|
Term
| What abnormalities directly lead to atlantoaxial instability? |
|
Definition
-aplasia of the dens
-dens hypoplasia
-dorsal dens angulation
-separation of the dens
-ligamentous instability |
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|
Term
| True or False: Up to 24% of dogs w/ A-A instability have a normal dens. |
|
Definition
|
|
Term
| What is the typical signalment of atlantoaxial instability? |
|
Definition
-young small breed dogs <1y
-toy poodle, Yorkies, Chihuahua |
|
|
Term
| What are the clinical signs of atlantoaxial instability? |
|
Definition
-neck pain: most traumatic but 30-60% congenital
-neuro deficites (95%): progressive tetraparesis, ataxia |
|
|
Term
| How do we diagnose atlantoaxial instability? |
|
Definition
-PE: DO NOT FLEX NECK
-signalment
-rads: inc distanc b/n dorsal arch of C1 & dorsal spinous process of C2
-CT
-MRI |
|
|
Term
| What are our major differentials for atlantoaxial instability? |
|
Definition
-maningitis
-syringomyelia
-discospondylitis
-disc dz |
|
|
Term
| What is the goal of medical management of atlantoaxial instability? |
|
Definition
| -stabilize joint hwile ligamentous structures heal |
|
|
Term
| Who are good candidates for medical treatment of atlantoaxial instability? |
|
Definition
-acute onset of CS w/out prior hx
-young dog w/ immature bone
-financial constraints |
|
|
Term
| How do we medically manage atlantoaxial instability? Outcome? |
|
Definition
-strict confinement: 6-8w
-neck brace
-pain meds
-good long-term outcome IF MINIMALLY AFFECTED |
|
|
Term
| What is the goal of surgical management of atlantoaxial isntability? |
|
Definition
-reduce further compression of spinal cord
-definitive stabilization of A-A joint (fusion) |
|
|
Term
| What is the typical complication rate seen w/ surgical management of atlantoaxial instability? Typical perioperative mortality? |
|
Definition
-50-70%
-GOLD STANDARD
-perioperative mortality: 10-30% |
|
|
Term
| What is the typical prognosis w/ medical management of A-A instability? |
|
Definition
-good long term prognosis in 40% of cases
-better if CS < 30d |
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