Disc Degeneration and Prognosis Flashcards
Disc degeneration can be sub classified how?
Chondroid
Fibroid
What breed is fibroid disc degeneration seen in?
Non-chondrodystrophoid breeds
What breed is chondroid disc degeneration seen in?
Chondrodystrophoid breeds
What age does chondroid degeneration occur in?
Early life
What age is fibroid degeneration seen in?
Later in life
In the thoracolumbar region, 85% of the disc pathology is found between ?
T10-L2
What is commonly the first sign seen?
Pain
Other than pain, what are the common signs of cervical lesions?
Muscular spasms
Gait abnormality
Why do gait abnormalities only tend to be seen with significant extrusion of disc material?
High spinal cord to vertebral canal ratio in the cervical spine
Hansen Type I Disc Extrusion:
A) What % of disc dx are Thoracolumbar discs?
B) Age at onset at clinical signs?
A) 65 %
B) 3-6 years
Hansen Type I Disc Extrusion:
A) Painful?
B) Acute vs chronic?
C) What breed?
A) Yes
B) Acute
C) Chondrodystrophic
Hansen type I disc extrusions are commonly seen in what specific breeds? (7)
Dachshunds,
terriers,
Basset Hounds,
Beagles,
Corgis,
French bulldogs
English Bulldogs
Hansen type I disc extrusion;
when does the degeneration happen, when are onset of clinical signs?
Degeneration in early life; usually between 3-6 years
Hansen type I disc extrusion
What happens?
Extrusion of nuclear disc material through the annulus fibrosus and as a result there is spinal cord compression AND contusion due to rapid extrusion of disc material.
How to diagnose Hansen type I extrusion? Modality of choice (*)
- Myelography
- CT myelogram
- Plain CT
- MRI - **
When does conservative therapy have a good prognosis with hansen type I extrusion?
Pain only or mild signs
What procedure is most commonly performed in the thoracolumbar spine to enable decompression of the entire area of spinal compression?
hemilaminectomy
How many hemilaminectomies can be performed without significant secondary spinal instability?
Up to 4
Hansen type II disc protrusion:
A) Age of onset of clinical sings?
B) Acute or chronic?
A) 8years +
B) Chronic
Hansen type II disc protrusion
A) Pain?
B) How common is mineralisation?
A) Not associated with pain
B) Rare
Fill in the blank: In Hansen type II lesions, there is generally [blank] of the dorsal annulus fibrosus.
Hyperthrophy
How does Hansen type II result in chronic spinal cord compression?
hypertrophy of the dorsal annulus fibrosus
With Hansen type II what happens over time? (2)
neuronal degeneration
spinal cord atrophy
Which modality is the best to diagnose Hansen type II lesions?
MRI
Other than MRI, what can be used to diagnose Hansen type II be diagnosed? (2)
- Myelography
- CT myelogram
What are the most commonly performed treatments for a Hansen Type II protrusion?
Lateral corpectomies
What do lateral corpectomies allow with the spinal cord?
decompression of the spinal cord with minimal manipulation of the spinal cord
Risks of lateral corpectomy? (2)
haemorrhage from the venous sinus
iatrogenic damage to the nerve root/peripheral nerve following the lateral approach.
Most common grading scale for disc dx?
5 points was developed by Ian Griffiths and modified by Wheeler and Sharp
What is the issue with the more detailed 1-14 scale?
Less practical to use for every day cases despite being more accurate.
With the 5 point scale, define grade 1?
Pain/no neurological deficits
With the 5 point scale, define grade 2?
Ataxia/ambulatory paresis
With the 5 point scale, define grade 3?
Non-ambulatory paresis
With the 5 point scale, define grade 4?
Plegia
With the 5 point scale, define grade 5?
Plegia with no nociception
With a grade I;
What is the % prognosis with:
A) Conservative?
B) Surgical?
A) 100
B) 97
With a grade I;
What is the recovery time with:
A) Conservative?
B) Surgical?
A) 3w
B) <2w
With a grade II;
What is the % prognosis with:
A) Conservative?
B) Surgical?
A) 84
B) 95
With a grade II;
What is the recovery time with:
A) Conservative?
B) Surgical?
A) 6w
B) <2w
With a grade III;
What is the % prognosis with:
A) Conservative?
B) Surgical?
A) 84
B) 95
With a grade III;
What is the recovery time with:
A) Conservative?
B) Surgical?
A) 6w
B) <2w
With a grade IV;
What is the % prognosis with:
A) Conservative?
B) Surgical?
A) 81
B) 95
With a grade IV;
What is the recovery time with:
A) Conservative?
B) Surgical?
A) 9-12w
B) 1-4w
With a grade V;
What is the % prognosis with:
A) Conservative?
B) Surgical?
A) 7
B) 64
With a grade V;
What is the recovery time with:
A) Conservative?
B) Surgical?
A) N/A
B) 5-10w
if a grade 5 is not presented for surgery within 48 hours, what is the prognosis?
<5%
Approximately half of the dogs that never recover deep pain sensation will demonstrate ambulation when?
at 18 months.
Other factors assciated with spinal dx outcome? (7)
Evidence of myelomalacia.
Lesions at the lumbar- or cervicothoracic intumescences.
Intramedullary changes (especially haemorrhage).
Hansen type II vs Hansen type I
Unfavourable underlying disease.
Age and body weight. The prognosis is usually worse with older and heavier patients.
Prolonged loss of nociception (especially when >48h).
What is Progressive myelomalacia (PMM) ?
A non-reversible fatal condition secondary to an acute spinal cord injury.
Progressive myelomalacia (PMM) is reported in how many Grade V dogs suffering from an acute spinal cord injury secondary to a thoracolumbar disc extrusion (Hansen type I)?
10-15%
PMM is a progressive ischaemic necrosis spreading where from the initial lesion?
Cranially and caudally
Fill in the blank: Myelomalacia; Clinically the patient will start to exhibit [blank] in the pelvic limbs, the cutaneous trunci cut off will progress cranially and the front legs will be affected as well as ability to ventilate, Horner’s syndrome can also be noticed (unilateral or bilateral).
LMN
Myelomalacia; Where will the cutaenous trunci cut off?
will progress cranially and the front legs will be affected as well as ability to ventilate
What syndrome maybe noticed with Myelomalacia?
Horners
