Lecture 9

Question 1

What are the characteristics of spondylosis deformans?

Answer 1

-bony spurs adjacent to disc
-non-inflammatory
-usually incidental
-lateral and ventral osteophytes
-may bridge disc space
-sclerotic endplates

Question 2

What is shown in this image?

Answer 2

spondylosis deformans

Question 3

What is shown in this image?

Answer 3

spondylosis deformans

Question 4

What is shown in this image?

Answer 4

spondylosis deformans

Question 5

What is discospondylitis?

Answer 5

actual infection of the disc and surrounding bone that can cause back pain and neurologic deficits

Question 6

What are the characteristics of degenerative myelopathy?

Answer 6

-aka german shepherd myelopathy
-progressive degeneration of axons and myelin in thoracolumbar white matter
-mutation in superoxide dismutase 1 (same gene as human ALS)
-seen in older german shepherds, boxers, and pembroke welsh corgis
-insidious onset of paraparesis

Question 7

What is shown in this image?

Answer 7

staining of myelin supportive of degenerative myelopathy (should be completely blue in white matter)

Question 8

How is degenerative myelopathy diagnosed?

Answer 8

-postural deficits in pelvic limbs
-normal or exaggerated spinal reflexes
-not painful (spinal cord has no pain receptors)
-genetic testing
-rule out other causes

Question 9

What are the differentials for degenerative myelopathy?

Answer 9

-chronic disc protrusion
-neoplasia
-lumbosacral stenosis
-myelitis
-orthopedic disorders

Question 10

What are the characteristics of degenerative myelopathy progression?

Answer 10

-no effective treatment
-neurologic deficits progress slowly; leads to euthanasia
-often unable to walk by ~ 6 months after diagnosis
-often become incontinent
-can affect front legs and brain with time

Question 11

What is degenerative lumbosacral stenosis?

Answer 11

-narrowing of lumbosacral vertebral canal with compression of cauda equina
-consists of ligament hypertrophy and fibrous disc protrusion

Question 12

Which dogs typically experience lumbosacral stenosis?

Answer 12

-middle aged, large breeds
-german shepherds
-other breeds of working dogs

Question 13

What is the typical history in lumbosacral stenosis patients?

Answer 13

-stiffness and pain
-pelvic limb lameness
-incontinence
-tail weakness

Question 14

What are the physical exam findings in lumbosacral stenosis?

Answer 14

-lumbosacral pain
-weak flexor reflexes
-weak perineal reflexes

Question 15

What are the radiographic findings in lumbosacral stenosis?

Answer 15

-spondylosis
-malalignment
-non-specific changes

Question 16

Which imaging modalities are best for diagnosing lumbosacral stenosis?

Answer 16

CT and MRI (MRI best)

Question 17

What are the characteristics of dorsal laminectomy for lumbosacral stenosis?

Answer 17

-hemilaminectomy not possible due to location of ileum
-done in cases with large disc protrusions
-often have to cut the discs out to correct problem
-may be accompanied by lumbosacral stabilization to decompress cord and stabilize the space

Question 18

What are the characteristics of cervical spondylomyelopathy/wobbler syndrome?

Answer 18

-compression of cervical cord due to malformation or malarticulation of vertebrae
-usually caudal cervical vertebrae

Question 19

What are the components of cervical spondylomyelopathy?

Answer 19

-stenosis
-malformed articular processes
-disc protrusion
-ligament hypertrophy

Question 20

Which dogs experience cervical spondylomyelopathy?

Answer 20

-young great danes and mastiffs
-older dobermans
-occasionally other breeds

Question 21

How does osseous wobbler differ from disc-associated wobbler?

Answer 21

-osseous wobbler has bony proliferation
-disc-associated wobbler is often in a doberman with one or more cervical disc protrusions

Question 22

What are the signs of cervical spondylomyelopathy?

Answer 22

-acute or chronic onset
-ataxia and paresis of all limbs
-neck pain

Question 23

What findings on radiographs correlate with cervical spondylomyelopathy?

Answer 23

-stenosis of canal
-subluxation
-malformation of vertebral body
-collapsed disc space
-degenerative changes

Question 24

What is shown on this myelogram?

Answer 24

ventral, extradural compression at C5 to C6 and C6 to C7

Question 25

How can extension and flexion of the neck be used in cervical spondylomyelopathy diagnosis?

Answer 25

compression may be exacerbated with either flexion or extension and show up better on imaging

Question 26

What is shown in these images?

Answer 26

left: normal CT right: bony stenosis

Question 27

What is the treatment for cervical spondylomyelopathy?

Answer 27

-dorsal laminectomy -stabilization with hardware and bone graft

Question 28

What is the prognosis for cervical spondylomyelopathy?

Answer 28

-variable and difficult to predict -worse for long-standing or multiple lesions -worse for dobermans with hypothyroidism, cardiomyopathy, and/or von Willebrand's dz which could prevent surgical treatment