Chpt 10 - SA Spinal cord

Question 1

Clinical signs of spinal shock

Answer 1

SYMMETRIC hypotonia/atonia pelvic limbs. Spinal reflexes absent or depressed. o Primates persist 2-3 weeks o Domestic animals – ↓ patellar reflexes persist few hours. ↓ W/D reflex may persist 10-14 days

Question 2

Where are border cells located? Where do the axons travel and synapse onto?

Answer 2

dorsolateral border of ventral gray in the L1-5 spinal cord segments. Axons travel in fasciculus proprius and synapse onto extensor LMN in cervical intumesence

Question 3

Explain central neurogenic pain

Answer 3

theorized disinhibition of the CBO in dorsal gray column that project into lateral/ventral spinothalamic tract. (see end of chpt 9)

Question 4

“FCEM is rare in chondrodystrophic breeds”. True or False?

Answer 4

True

Question 5

FCEM embolus which 2 locations can they originate from?

Answer 5

1. Nucleus pulposus 2. Cartilage from vertebral endplates of growing dogs

Question 6

Schmorl’s node. what is that? Is it more common in biped vs quadruped?

Answer 6

Disk material protrude through the endplate and into the adjacent vertebral body. Common in bipeds and rare in quadrupeds. Also dogs have thick cortical bone at the end plate

Question 7

Nephroblastoma 1) Location along spinal cord? 2) Location in spinal canal (intra/extradural? Intra/extramedullary?)

Answer 7

1) T10-L2 2) intradural extramedullary

Question 8

Nephroblastoma 1) what is it called in children? And where is it located in the human vs dog? 2) Mutation in which chromosome? 3) histopath findings of Wilm’s tumor? In human vs. dog 4) immunohistochem marker?

Answer 8

1) Wilm’s tumor - usually occurs in kidney. In dogs more common adj to spinal cord but can also occur in kidney. Not reported to occur in both locations in the same patient. 2) Chromosome 11 3) 3 components: (i) sheets or unorganized epith cells (blastemal cells) (ii) tubular elementsl lined by cells varying from squamous to cuboidal (iii) Fibrous component consisting of bundles of collagen ** canines only have first 2 components** 4) polysialic acid marker

Question 9

Diskospondylitis 1) most common isolate 2) other isolates? (name 4) 3) Name 1 breed predisposition

Answer 9

o Most common isolate = Staphylococcus pseudintermedius o Other isolates: Streptococcus spp, E. coli, Brucella canis o GSD that are not responding well to AB, consider fungal infection o Airedale breed may be predisposed - ↓ serum IgA, ↑ serum B1-globulins, and blastogenesis suppressing factors Other notes: o Auscultate for murmur – bacterial endocarditis may be the source o Migrating plant awn

Question 10

Multiple cartilaginous exostosis 1) what is it? 2) common areas affected? 3) Features of disease in dogs vs cat?

Answer 10

uncommon disorder of young animals that can involve spinal cord. Benign proliferations of cartilage and bone associated with growth plates. o Common areas: long bones, ribs, vertebrae o Stop growing when normal growth plates stop o But in the cat they continue to grow Note: Occasionally becomes neoplastic and continues to grow.

Question 11

The most common spinal cord neoplasm in cats

Answer 11

lymphoma

Question 12

The most common spinal cord neoplasm in cattle

Answer 12

lymphoma

Question 13

IVDD: What kind of metaplasia do chondrodystrophic dogs undergo? Describe what that is in terms of pathology the disk and any other surrounding structures

Answer 13

Chondroid metaplasia • hyalin cartilage replaces nucleus, further degen causes calcification of nucleus. ↑ rigidity in nucleus leads to tears in annulus and extrusion of degen material • Degenerative joint disease of fibrocartilagenous joint • Proliferation of annular fibers secondary to degen of nucleus and chronic malarticulation → protrusion

Question 14

IVDD: what kind of metaplasia do non chondrodystrophic breeds undergo?

Answer 14

Fibrous metaplasia – nonchondrodystrophic breeds. Degen starts 4-5 years old • Replacement of nucleus with fibrocartilage

Question 15

what is an explanation that the T1-T10 vertebrae are more resistant to IVDE?

Answer 15

Between T1-T10 there is intercapital ligament that courses transversely across the dorsal surface of the disk to connect heads of the ribs where they articulate with adj vertebrae. Added support may prevent IVDE.

Question 16

Degenerative myelopathy: describe the neuropath findings

Answer 16

1) neuropathology: • Missense mutation of SOD1 • Diffuse axonal necrosis primarily in lateral and ventral funiculi of TL spinal cord segments • Secondary demyelination and astrogliosis associated with the axonopathy • +/- neuronal cell body degeneration in few brainstem nuclei

Question 17

Degenerative myelopathy: Describe the 4 stages of progression of clinical signs

Answer 17

i. Ambulatory pelvic limb UMN paresis and GP ataxia ii. Nonambulatory paraparesis, GP ataxoa → paraplegia and areflexia, mild muscle atrophy, incontinence iii. LMN paraplegia with thoracic limb paresis and ataxia iv. LMN tetraplegia, severe atrophy, dysphagia, tongue paresis

Question 18

Superoxide dismutase 1 what does this protein do?

Answer 18

Enzyme converting oxygen radical –> H2O2 and O2 antioxidant property

Question 19

Young Shiloh dogs and TL disease - what comes to mind?

Answer 19

Young Shiloh Shepherd dogs – DJD of one more articulating facet joints between T11-L2, causing compression of spinal cord. Occur

Question 20

Afghan Hound myelinolysis: 1) Age of onset 2) mode of inheritance 3) underlying etiology 4) Pathology 5) Clinical signs and progression

Answer 20

1) Onset clinical signs 3-13 months of age 2) autosomal recessive gene disorder. 3) Primary demyelination disorder. 4) Necrosis of myelin, sparing axons. Bilateral symmetric in all funiculi but spares fasiculus proprius o Most have same 1° demyelin of axons around the dorsal nucleus of trapezoid body. No clinical signs attributable here o Starts midthoracic and progresses cranially and caudally 5) Starts mild pelvic limb spasticity, paresis, ataxia → loss of trunk muscles by 7-10 days o Recumbency by 14-21 days

Question 21

Which disk space in the cervical spine is normally narrower than others?

Answer 21

C2-3

Question 22

Which is the most common cervical vertebra to fracture?

Answer 22

cranial aspect of C2

Question 23

Which is the most common site in the cervical spine to have intervertebral disk disease

Answer 23

C2-3

Question 24

How do you categorize these spinal cord neoplasms in terms of location? (e.g. intra vs extradural, etc) 1. meningioma 2. nerve sheath tumor

Answer 24

1. meningioma - intradural, extramedullary 2. PNST - intradural, extramedullary

Question 25

In the spine, where are meningiomas most likely located

Answer 25

C1-2

Question 26

Name the ossification centers.

The dotted lines indicate where centers of ossication fuse. Give the times of fusion

Answer 26

Question 27

Meningeal fibrosis what is it?

Young or old?

Breeds? name 3

Answer 27

Meningeal fibrosis – fibrosis of arachnoid trabeculae, thickening of the dura causing compressive myelopathy.

YOUNG, LARGE-BREED dogs: Rottweiler, Bernese Mountain Dog, Labrador Retriever
Assoc subarachnoid diverticulum and syrinx common
Edema of cord caudal to fibrosis common

Question 28

A disruption to the UMN control to the sympathetic nerves can cause a change in skin temperature.

Does it make the skin warmer or cooler?

Answer 28

warmer

Question 29

Globoid cell leukodystrophy (Krabbe’s disease in children)

1) Name 2 breeds
2) Mode of inheritance?
3) Pathophysiology

Answer 29

Globoid cell leukodystrophy (Krabbe disease in children) –

1) most common in West Highland Terrier and Cairn Terrier.
2) Autosomal recessive

3) Deficiency in lysosomal enzyme – galactosylceramidase 1 (beta-galactocerebrosidase)
Type of storage disease – accumulation of pychosine (galactosylsphingosine) – toxic to oligodendrocytes and Schwann cells à primary demyelination disorder
Diffused progressive white matter tract signs
Recumebency, dementia, blindness, death in 1-2 years
Globoid cells are macrophages (gitter cells) filled with phagocytized myelin remnants