Principles of spinal and lumbosacral disease Flashcards
What occupies the lumbosacral vertebral canal?
the cauda equina (collection of spinal nerves)
Why is the vertebral column longer than the spinal cord?
spinal cord ends around L6-L7 in most dogs and extends further caudally as the cauda equina
What are the 4 functional segments of the spinal cord?
c1-c5
c6-t2
t3-l3
l4-s3
Which spinal cord section control bladder function?
t3-l3 (bladder relaxation and integral sphincter contraction
l4-s3 (bladder contraction and external sphincter contraction)
What are the main clinical signs in an animal with spinal cord disease?
ataxia, paresis, plegia
spinal hyperaesthesia
bladder dysfunction
gait abnormality usually = ataxia + paresis
What is ataxia?
without order
incoordination
sensory phenomenon
What is paresis?
decreased voluntary movement
motor phenomenon
ambulatory or non ambulatory
UMN or LMN in nature
What is plegia?
absence/complete loss of voluntary movement
What causes spinal hyperaesthesia?
spinal cord has no pain receptors but surrounding structures have an abundance
intrinsic spinal cord disorders will not be painful
What is the difference between urinary/fecal continence and incontinence?
continence: ability to fill and empty bladder/intestines voluntarily
incontinence: loss of ability to fill and empty bladder/intestines voluntarily
What type of bladder dysfunction is seen when lesions are in the thoracolumbar spinal cord segments?
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
What type of bladder dysfunction is seen when lesions are in the s1-s3 spinal cord segments?
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
What does urine retention increase risk of?
urinary tract infections
common in non-ambulatory
How can we manage bladders in animals with spinal disease?
should be emptied in non-ambulatory spinal patient to avoid problems
- manual bladder expression or with a catheter
What are clinical presentations of dogs with cauda equina syndrome?
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
What is a schiff-sherrington posture?
acute t3-l3 injuries
provide inhibition to extensor muscles of thoracic limbs
indiction of localisation NOT prognosis
How can the gait tell us if an animal has spinal cord vs lumbosacral disease
spinal: ataxia and paresis
lumbosacral: paresis or lameness
What can proprioception tell us about an animal?
reliable indicator for presence of neuro disease!!!
deficits can be seen in animals with spinal, brainstem and forebrain disease
What is the progressive sequence of neuro deficits in animals with acute spinal disease?
proprioceptive deficits
paresis and ataxia
plegia
bladder dysfunction
tail dysfunction
pain sensation/nociception
** proprioceptive deficits always occur before gait abnormalities
What does an absent or decreased spinal reflex indicate?
lesion is localised in reflex arc
What characterizes animals with lumbosacral disease?
sciatic nerve dysfunction
splits into peroneal nerve and tibial nerve
What is the clinical presentation of tibial nerve dysfunction?
dropped hock, plantigrade stance in cats
loss of hock flexion during withdrawal
When is it necessary to test nociception?
plegic animals
differentiate stupor from coma
suspicion of sensory neuropathy (rare)
Does limb withdrawal indicate pain perception?
NO
needs a conscious reaction: vocalisation, trying to flee, trying to bite, etc.
