Principles of Spinal Disease Flashcards
What makes up the grey and white matter in the spinal cord?
Grey - nerve cell bodies
White - axons
How are spinal cord disorders typically characterised?
A comination of sensory and motor dysfunction - ataxia and paresis.
How do ataxia and paresis differ?
Ataxia - Loss of coordination, sensory dysfunction
Paresis - weakness, motor dysfunction
Why are intrinsic spinal cord disorders not painful?
The spinal cord has no pain receptors
Where in the spine does the spinal cord end?
L6-L7
What are the four functional segments of the spinal cord?
C1-C5
C6-T2
T3-L3
L4-S3
What parts of the spinal cord are responsible for innervation to the bladder?
L1-4 Dog
L2-5 Cats
S1-S3
Define myelopathy…
A disorder of the spinal cord
Define paresis and plegia…
Paresis - decreased voluntary movement
Plegia - absence of voluntary movement
Define: Mono- Para- Hemi- Tetra-
Mono - one limb affected
Para - Both pelvic limbs affected
Hemi - Ipsilater thoracic and plevic limb affected
Tetra - all four limbs affected
Define urinary/faecal incontinence.
Loss of ability to fill and empty the bladder/intestines voluntarily
What are the signs of urinary incontinence?
Dripping of urine constantly
No urine output
Give 3 examples of postures seen in spinal cord disorders…
Crouched
Low head carriage
Schiff-Scherrington
What tests can be used to identify the segment of spinal cord affected in disease?
Spinal reflexes
What are the spinal reflexes tested?
Patella reflex
Withdrawal reflex
Cutaneous trunci
What can cause decreased spinal reflexes? What are the signs seen?
Lesions in the reflex arc of C6-T2 or L4-S3
LMN signs
What can cause exaggerated spinal reflexes? What signs are seen?
Lesion located cranial from the reflex arc - in C1-C5 or T3-L3
UMN signs
Why do UMN lesions cause exaggerated spinal reflexes?
UMN system normally inhibits/controls muscle tone and reflexes of LMN.
When is it appropriate to test nociception in the neurological exam? Why?
If an animal is paraplegic only.
Pain sensation is lost only once an animal has become paraplegic, not before.
What are the clinical signs of spinal disease?
No gait abnormalities Spinal hyperaesthesia Ataxia or paresis Plegia Bladder dysfunction
What abnormailites are found on neuro exam with spinal disease?
Proprioceptive deficits
+/- spinal reflexes
+/- spinal hyperaesthesia
Reduced nociception in plegic animals
What are the signs of a lesion located in C1-C5?
Tetraparesis, ataxia in all limbs
Proprioceptive deficits in all limbs
Intact/increased spinal reflexes in all limbs
Normal/increased muscle tone in all limbs
+/- Horner’s syndrome
What are the signs of a lesion located in C6-T2?
Tetraparesis, ataxia in all limbs
Proprioceptive deficits in all limbs
Intact/decreased spinal reflexes and muscle tone in thoracic limgs
Intact/increased spinal reflexes in pelvic limgs
Disconnected gait
+/- Horner’s
What are the signs of a lesion located in T3-L3?
Normal thoracic limbs Paraparesis and ataxia in pelvic limbs \+/- paraplegia Intact/increased spinal reflexes and muscle tone in pelvic limbs Urinary dysfunction \+/- Schiff-Sherrington posture
