Principles of spinal and lumbosacral disease

Question 1

What occupies the lumbosacral vertebral canal?

Answer 1

the cauda equina (collection of spinal nerves)

Question 2

Why is the vertebral column longer than the spinal cord?

Answer 2

spinal cord ends around L6-L7 in most dogs and extends further caudally as the cauda equina

Question 3

What are the 4 functional segments of the spinal cord?

Answer 3

c1-c5
c6-t2
t3-l3
l4-s3

Question 4

Which spinal cord section control bladder function?

Answer 4

t3-l3 (bladder relaxation and integral sphincter contraction
l4-s3 (bladder contraction and external sphincter contraction)

Question 5

What are the main clinical signs in an animal with spinal cord disease?

Answer 5

ataxia, paresis, plegia
spinal hyperaesthesia
bladder dysfunction

gait abnormality usually = ataxia + paresis

Question 6

What is ataxia?

Answer 6

without order
incoordination
sensory phenomenon

Question 7

What is paresis?

Answer 7

decreased voluntary movement
motor phenomenon
ambulatory or non ambulatory
UMN or LMN in nature

Question 8

What is plegia?

Answer 8

absence/complete loss of voluntary movement

Question 9

What causes spinal hyperaesthesia?

Answer 9

spinal cord has no pain receptors but surrounding structures have an abundance

intrinsic spinal cord disorders will not be painful

Question 10

What is the difference between urinary/fecal continence and incontinence?

Answer 10

continence: ability to fill and empty bladder/intestines voluntarily

incontinence: loss of ability to fill and empty bladder/intestines voluntarily

Question 11

What type of bladder dysfunction is seen when lesions are in the thoracolumbar spinal cord segments?

Answer 11

UMN bladder
increased tone detrusor muscle
increased tone urethral musculature

bladder keeps filling but can’t empty = could overflow/rupture
resistance to manual expression
inconsistent leakage from overly full

Question 12

What type of bladder dysfunction is seen when lesions are in the s1-s3 spinal cord segments?

Answer 12

LMN bladder
decreased tone detrusor muscle
decreased tone urethral musculature

bladder leaks without any pressure at all
can leak urine spontaneously causing skin irritation and UTIs

Question 13

What does urine retention increase risk of?

Answer 13

urinary tract infections
common in non-ambulatory

Question 14

How can we manage bladders in animals with spinal disease?

Answer 14

should be emptied in non-ambulatory spinal patient to avoid problems
- manual bladder expression or with a catheter

Question 15

What are clinical presentations of dogs with cauda equina syndrome?

Answer 15

often vague and unspecific clinical signs
paresis without ataxia
pelvic limb lameness
spinal hyperaesthesia can be present
often pain on extension hips and on dorsal extension tail
decreased tail tone
urinary/faecal incontinence

often no neuro deficits

Question 16

What is a schiff-sherrington posture?

Answer 16

acute t3-l3 injuries

provide inhibition to extensor muscles of thoracic limbs
indiction of localisation NOT prognosis

Question 17

How can the gait tell us if an animal has spinal cord vs lumbosacral disease

Answer 17

spinal: ataxia and paresis

lumbosacral: paresis or lameness

Question 18

What can proprioception tell us about an animal?

Answer 18

reliable indicator for presence of neuro disease!!!
deficits can be seen in animals with spinal, brainstem and forebrain disease

Question 19

What is the progressive sequence of neuro deficits in animals with acute spinal disease?

Answer 19

proprioceptive deficits
paresis and ataxia
plegia
bladder dysfunction
tail dysfunction
pain sensation/nociception

** proprioceptive deficits always occur before gait abnormalities

Question 20

What does an absent or decreased spinal reflex indicate?

Answer 20

lesion is localised in reflex arc

Question 21

What characterizes animals with lumbosacral disease?

Answer 21

sciatic nerve dysfunction
splits into peroneal nerve and tibial nerve

Question 22

What is the clinical presentation of tibial nerve dysfunction?

Answer 22

dropped hock, plantigrade stance in cats
loss of hock flexion during withdrawal

Question 23

When is it necessary to test nociception?

Answer 23

plegic animals
differentiate stupor from coma
suspicion of sensory neuropathy (rare)

Question 24

Does limb withdrawal indicate pain perception?

Answer 24

NO
needs a conscious reaction: vocalisation, trying to flee, trying to bite, etc.

Question 25

What are the indications for LMN lesions?

Answer 25

loss of stimulation or excitation
decreased muscle tone: flaccid paralysis
decreased spinal reflexes

Question 26

What are the indications for UMN lesions?

Answer 26

loss of inhibition = disinhibition
excessive stimulation or excitation
increased muscle tone: spastic paresis
increased spinal reflexes

Question 27

How do we know if an animal is for sure neurological?

Answer 27

PROPRIOCEPTION

Question 28

How can number of limbs tell us about the spinal neuro-anatomical localisation?

Answer 28

all 4: c1-c5 or c6-t2
only pelvic: t3-l3 or l4 s3

Question 29

How can spinal reflexes/muscle tone tell us about spinal neuro-anatomical localisation?

Answer 29

increased: c1-c5 or t3-l3
decreased: c6-t2 or l4-s3

Question 30

What are the 10 most common spinal conditions in dogs?

Answer 30

type 1 intervertebral disc disease
type 2 intervertebral disc disease
ischaemic myelopathy
neoplasia
syringomyelia
immune-mediated myelitis
acute non-compressive nucleus pulpous extrusion
degenerative lumbosacral stenosis
cervical spondylomyelopathy
steroid responsive meningitis arteritis
spinal arachnoid diverticulum

Question 31

What are the 10 most common spinal conditions in cats?

Answer 31

neoplasia other than lymphoma
intervertebral disc disease
vertebral fracture and luxation
ischaemic myelopathy
feline infectious peritonitis virus
spinal lymphoma
thoracic vertebral canal stenosis
acute non-compressive nucleus pulpous extrusion
traumatic spinal cord contusion
spinal arachnoid diverticulum