Spinal cord injury

Question 1

Grade 1	
Grade 2	
Grade 3	
Grade 4	
Grade 5

Answer 1

Grade 1	No deficits
Grade 2	Paresis, walking
Grade 3	Paresis, nonambulatory
Grade 4	Paralysis
Grade 5	Paralysis, no deep pain

Question 2

Two stages of spinal cord injury follow trauma:

Answer 2

primary tissue damage - direct mechanical disruption secondary damage via biochemical and vascular events

Question 3

excitatory NT - Glutamate binds to:

mech compression compromises:

Answer 3

NMDA receptors - voltage-sensitive Ca and Na
= increased intracellular Ca Na

blood flow

Question 4

trauma and nonambulatory animal should be:

Answer 4

• placed on a flat board and strapped down

- full spinal rads

Question 5

only spinal cord segments ____ and ____ are located in the vertebral body with the same vertebral number

-more caudally along the spine, the spinal cord segments lie in the spinal canal____ to the vertebrae with the same number

important to consider when evaluating ____ of the spine

i.e. fx L5 = abnormality of spinal cord segments:

Answer 5

C1, C2, and T13, L1, L2

cranial

rads

L7, S1, S2, S3, and Cd1

Question 6

floating limbs - localize
two-engine gait

cervical intumescence gives rise to spinal nerves:

Answer 6

Spinal ataxia C1-C5
C6-T2

subscapular
suprascapular
musculocutaneous
axillary
radial
median
ulnar nerves

Question 7

Spinal Shock:
cranial or caudal or both to lesion?
duration:
emplifies the importance of:

Answer 7

profound depression of segmental reflexes
caudal
transiently - 12 to 24 hours after an injury
serial exams

Question 8

animal limping or carry a thoracic limb ddx:

ddx

Additional signs may include absence of:

_____’s syndrome
decreased thoracic wall movement

Answer 8

ortho vs nerve root signature

proprioceptive deficits
nonuniform muscle atrophy over the limb
electrodiagnostic testing

may be absent (unilateral or bilateral) as a result of damage to the LMNs that contribute to the lateral thoracic nerve (C8-T1)

miosis, ptosis, and enophthalmos
damage to the sympathetic fibers that leave the spinal cord at this level

bc inability of the brainstem to control intercostal nerve function. If only the phrenic nerve is functioning properly, diaphragmatic (abdominal) breathing may be seen

Question 9

cutaneous trunci reflex is tested at

MoA:
sensory n. dermatome enters spinal cord approx:

.:. absence of a cutaneous trunci reflex at L5 =

plus pain helps ID

Answer 9

level of the L5 vertebral body

interruption of sensory input from stimulated dermatome 2 vertebral bodies cranial to the level of stim.

lesion at vertebral body L3
but spinal n segment approx L4-6

Question 10

Schiff-Sherrington phenomenon MoA:

ddx from C1-C5:

Answer 10

increased tone to the thoracic limbs from T3-L3 lesion

• lack of ascending inhibitory input to the thoracic limbs –
• originating from the border cells located T3-L3
• border cells responsible for tonic inhibition of extensor muscle α-motor neurons in the cervical intumescence

normal CP, voluntary motor function

Question 11

L4-S1 lumbar intumescence and give rise:

Answer 11

femoral (not shared with S1-S3)
obturator
sciatic
pelvic
pudendal nerves

Question 12

S1-S3 give rise:

femoral nerve is spared with an injury .:. spinal reflex:

Answer 12

sensory fibers that contribute:
sciatic
pelvic
pudendal
perineal nerves (not shared with L4-S1)

coxofemoral joint flexion
without flexion of the tarsocrural joint

Question 13

dx:
radiographs most useful sign
senistivity
PPV (i.e. miss)

Ct is good for what breed:

CT misses:

Answer 13

narrowed intervertebral space
moderate sensitive: 65%
moderate predictive value: 70% (miss 30%)

chondrodystrophoid
-bc commonly develops intervertebral disk mineralization

• peracute small volume disc extrusion
• intramedullary lesions
• noncompressive nuclear pulposus extrusions

Question 14

Tx:

why IVFT?

Answer 14

-presumed compromise of spinal cord vasculature
-inhibits the normal autoregulation
=blood flow to spinal cord is dependent on MAP

Question 15

Surgical treatments per location:

Displaced or unstable fractures of the cervical spine:

Thoracic or lumbar vertebral column:

IVDD:

Answer 15

• for animals with statis neurologic status
• external support and strict rest
• due to the high incidence of mortality (approx 40%) associated with surgical intervention for cervical fractures
• smaller dogs may be splinted ventral cervical region
• larger dogs often need dorsal and ventral
• splinting the thoracic/lumbar challenging
• surgical stabilization is recommended for:
• displaced or unstable fractures

1. Grade 3 or greater deficits (non-ambulatory paresis)
2. recurrent episodes
3. episodes unresponsive to mx tx

Question 16

Sacrococcygeal or intracoccygeal fractures or luxations
-common injury after trauma in cats
b/c of:
neurologic deficits devastating in cats because:

Px: depends on the extent of the injury. Prompt surgical Tx:

Answer 16

tractional injury to the tail

extension of the spinal cord more caudally (to the level of the sacrum) compared with dogs

depends on the extent of the injury
surgical stabilization and tail amputation

Question 17

AA subluxations
Px: conservatively (i.e., splint stabilization):
relapse:

surgically:

Surgical fixation has been indicated as the treatment of choice why?:

Answer 17

-resulting in severe neurologic deficits
-treated conservatively good to guarded px:
(good outcome in 62.5% of dogs)
25%

good to guarded px
success 61% to 91%

prevent recurrence of signs

Question 18

Fracture criteria necessitating repair:

Luxations requiring repair:

B/c:

Answer 18

• incorporates articular facets
• vertebral body, or both

compromised the ventral buttress:
vertebral body
dorsal and ventral longitudinal ligaments
intervertebral disks

-susceptible to rotation

Question 19

Trauma = spinal lux. fx and LOSS OF DEEP PAIN:
px.

loss of deep pain for > 12 to 24 hours after injury

Answer 19

grave
9 cases of traumatic injuries = loss of deep pain
-none of the dogs regained deep pain
6 treated conservatively
3 treated surgically
2/9 regain the ability to walk (spinal walking)

loss of deep pain sensation bc thoracolumbar luxation or fracture = <10% recovery rate (i.e., motor ability)

poor to grave prognosis

Question 20

IVDD and loss deep pain:

Answer 20

varying rates of recovery (25% to 76%)

lack of deep pain perception
surgically via decompressive hemilaminectomy
58% regained the ability to walk and DPP
11% regained the ability to walk but not DPP

Question 21

paraplegia but retained deep pain px:

Answer 21

86% to 96% success

Question 22

10% IVDD loss of deep pain develop

Answer 22

ascending descending myelomalacia

Question 23

Progressive myelomalacia (PMM) is one of the most sinister complications of:

MoA:

Answer 23

thoracolumbar intervertebral disc extrusion

progressive ascending and/or descending
-hemorrhagic necrosis of the cord following acute, severe thoracolumbar spinal cord injury (SCI) due to acute IVDE

Question 24

CS:

Answer 24

complete sensorimotor loss in the pelvic limbs and the tail, loss of spinal reflexes in the pelvic limbs, loss of abdominal tone

• advancement of the caudal border of the cutaneous trunci muscle reflex
• loss of reflexes in the thoracic limbs, bilateral Horner’s syndrome and respiratory distress

Question 25

time:
prevalence in all:
paraplegic pain perception negative dogs:
breed:

Answer 25

usually 48 hours of trauma - may be delayed
2%
9 to 17.5%
33% was reported in French bulldogs