NEUROLOGY - Diseases of the spinal cord

Zygapophyseal joints (farticualar facets)


Anulus fibrosis


Nucleus pulposis


What indicates a normal intervertebral disc on MRI?

Well hydrated nucleus pulposis (white segment) and normal disc space width

What indicates a normal intervertebral disc degeneration on MRI?

Poorly hydrated nucleus pulposis (smaller white segment)

What is the pathogenesis of normal intervertebral disc degeneration?

Fibrous metaplasia where there is dehydration and proliferation replacement of the nucleus with collagen

What is often a normal ageing feature of the spine?

Spondylosis and rarely causes nerve entrapment (not an indicator for spinal disease)

What are the 3 main types of disc disease?

Non-compressive hydrated nucleus pulses extrusion (traumatic or running really fast), disc extrusion and disc protrusion

What is Hansen type 1?

Disc extrusion caused by chondroid degeneration of the nucleus pulposis, becomes calcified; associated with compression and contusion of the spinal cord

What is Hansen type 2?

Disc protrusion caused by continued progressive fibroid degeneration, annulus degeneration, tearing and hypertrophies causing progressive compression

Which disc disease is associated with chondrodystrophic breeds?

Hansen Type 1 (extrusion)

What breeds are typically associated with traumatic disc disease?

Typically GSD and sight hounds (but can be any)

What breeds are typically associated with Hansen Type 1 disc disease?

Chondrodystrophic such as Dachshunds, French Bulldogs, also GSDs, over the age of 2

What breeds are typically associated with Hansen Type 2 disc disease?

Typically non-chondrodystrophic large breeds over the age of 2

Which disc disease presents as peracute and non-progressive?


Which disc disease presents as acute and non-progressive?

Disc extrusion (or traumatic)

Which disc disease presents as insidious but progressive?

Disc protrusion

Which disc disease may be very painful?

Disc extrusion or traumatic initially

Which disc disease is not usually associated with pain (or very mild)?

Disc protrusion

Which disc disease is strongly asymmetrical?

Traumatic or disc extrusion

Which disc disease is mildly asymmetrical?

Disc protrusion

What are the principles of conservative treatment for thoracolumbar disc extrusion?

Rest up to 5 weeks to prevent further extrusion, steroid are not effective but NSAIDs may be indicated for pain.

How long does spinal contusion take to resolve?

Oedema resolves of 3-6 weeks

How long does spinal compression take to resolve?

Revascularisation takes place over weeks to months

What is the principle of surgical treatment for thoracolumbar disc disease?

Approach is determined by localisation of the compression

Where is the most common location for spinal cord compression?


What surgical approach is indicated for ventrolateral spinal cord compression?


What surgical approach is indicated for lateral or dorsolateral spinal cord compression?

Hemilaminectomy or corpectomy

What is the description of Grade 1-2 disc extrusions?

Pain only or ambulatory paraparetic

What is the description of Grade 3 disc extrusions?

Non-ambulatory paraparetic (partially paralysed)

What is the description of Grade 4 disc extrusions?


What is the description of Grade 5 disc extrusions?

Pain negative

For which grades of dic extrusions would there be little benefit of surgery?

Dogs that can walk

For which grades of dic extrusions would the benefit of surgery significantly be better than no-surgery?

Those that are pain negative (5), 60% recovery with and 10% without

What is outcome of dic extrusions not dependent on?

Time to surgery and duration of clinical signs

Why are dogs that have had surgery at a lower risk of relapse?

Fenestrations of the disc at risk are always done at the same time

Which spinal disc diseases will not benefit from decompresscive surgery?

Acute non-compressive hydrate nucleate pulposis extrusions

What is the prognosis if nothing is done following disc protrusions

May improve and recover esp. if mild ataxia and pain only, 18% recurrence rate

When would you consider surgery for disc extrusions?

If non-ambulatory

When would you consider PTS for disc extrusions?

If surgery is not an options and the disc extrusion is grade 5

When is surgery indicated for thoracolumbar disc protrusions?

For progressive cases

What is the improvement rate following surgery for thoracolumbar disc protrusions?


What may be the presentations of cervical disc extrusions?

Usually very painful (unless they have neuro deficit) and this may be the only sign but may also be tetraparetic, acute onset and progressive, symmetrical

What signalment will never be associated with disc disease?

Animals less than 2

What is treatment for cervical disc extrusions?

Ventral slot or rest

What is the prognosis for cervical disc extrusions?

50-80% for conservative treatment but may recur, excellent with surgery

What are the two types of disc problems that are make up the Wobbler's disease

Disc protrusions or hyperplasia

What are the degenerative changes associated with disc protrusions?

Flaval and dorsal ligament hypertrophy, disc prolapse

Flaval ligament


What changes are associated with degenerative hyperplasia; Wobbler's Syndrome Type 2?

Articular facet hypertrophy (more moon) and vertebral malformation (less common)

Which breeds are particularly associated with Wobblers disease?

Doberman, giant breeds whippets/lurchers

What is the presentation of Wobbler's disease?

Insidious, slowly progressive, usually symmetrical, usually not painful (but can be),

What part of the spinal cord is affected by Wobbler's disease?

Cervical; usually C6-T2

What are the treatment options for Wobbler's disease?

Ventral slot or distraction fusion

What will be consequence of disc disease at the lumbar sacral junction?

The cauda equina, which runs over this region, only contains nerve roots. Therefore, you will get severe pain and LMN paresis but few neurological deficits

What would be the consequence of sacral root compression?

Tail flaccidity and incontinence

Why is meant by transitional vertebrae?

Found at the lumbosacral junction and are vertebrae that have lumbar and sacral characteristics.

Which dogs are more predisposed to lumbosacral disease?

Those with more transitional vertebrae i.e. young and GSDs

What is the presentation of lumbosacral disease?

Acute/insidious, non-progressive, symmetrical/single limb, painful

What are the treatment options for lumbosacral disease?

Rest epidural steroids, surgical stabilisation and/or depression

What is the prognosis associated with lumbosacral disease?

80% improvement with 3 steroid injections, 50% cure and 80% improvement following surgery

What is meant by myelomalacia?

Progressive spinal cord liquefaction 1-5 days after any spinal cord injury

What signs are associated with myelomalacia?

Agitation/lethargy, hyper or hypometria, ascending cutaneous trunci reflex cut-off

What is usually the aetiology of ischaemic myelopathy?

Fibrocartilagenous embolism (FCE) which lodges in the ventral artery

Have do fibrocartilagenous emboli behave almost identically to and how can they be diffentiated?

Acute non-compressive HNPE which has a faster onset, may be initially associated with pain, and occurs more commonly in very active dogs

What are the presentation of ischaemic myelopathy?

Acute, non-progressive, asymmetrical, non-painful and can be anywhere in the spine

What is the possible treatment for ischaemic myelopathy?

No surgical treatment available

What is the possible treatment for non-compressive HNPE?

No surgical treatment available

What is the prognosis associated with ischaemic myelopathy?

50% return to walking and lack of incontinence is grade 5, 75% is grade 4 and 100% grades 1-3

What is a common cause of haemorrhagic myelopathy?

Angistrongylus (lungworm)

What is often also seen with haemorrhagic myelopathy?

Scleral, mussel or subdermal haemorrhages

How should spinal fractures be diagnosed?

2 orthogonal radiographic views or CT

What is likely if paresis occurs at exercise without trauma?

FCE and HNPE (more likely than spinal fractures)

A GSD Bernese and Corgi over 6 years old are associated with what disease?

Degenerative myelopathy

What is the presentation of degenerative myelopathy?

Insidious, slowly progressive, asymmetrical (weirdly), non-painful

Where is the degenerative myelopathy usually located?

Usually T3-L3

What is the genetic predisposition associated with degenerative myelopathy?

SOD1 mutation

What is the prognosis for degenerative myelopathy?

Usually ends in PTS, 2 month serval with non interventions (up to 8-9 with intense physio)

What is the aetiopathogenesis of arachnoid fibrosis/diverticulum?

Progressive obstruction to CSF flow around the spinal cord due to menial injury or developmental anomaly

Which breeds are more commonly associated with arachnoid fibrosis/diverticulum?

Small brachycephalic dogs

What is presentation associated with arachnoid fibrosis/diverticulum?

Insidious, slowly progressive, non-strong asymmetry, non-painful

Where is arachnoid fibrosis/diverticulum usually localised?

C1-T2 or T3-L3

What is seen in 60% of cases of arachnoid fibrosis/diverticulum?

Faecal incontinence

Arachnoid fibrosis/diverticulum


Why can arachnoid fibrosis/diverticulum cause a lot of damage compared to other compressions?

Dynamic compression with heart beat

What is the treatment for an arachnoid fibrosis/diverticulum?

May not need surgery is static, surgery usually involves removing adhesions, stabilising spine or diverting CSF flow if necessary

What is the aetiopathogenesis of vertebral malformations?

Defects in bone formation causing deformity in the spine, damage by instability direct compression or adjacent disc protrusion

What is the presentation of vertebral malformations?

Insidious, slowly progressive, can have acute episodes, no strong asymmetry, pain only on palpation

Where is the most common location of vertebral malformations?


Which tumours are associated with a reasonable prognosis?

Multiple myelomas and Meningiomas

What do dogs less than 2 years old with neck pain and no neuro deficits probably have?


What is the presentation of SRMA?

Acute, strongly waxing and waning with 5-12 day episodes, symmetrical, very painful

What is SRMA?

Immune mediated inflammation of the meninges and small arteries, associated with pyrexia and lethargy as systemic disease

Which breeds are associated with SRMA?

Beagle, Boxer, Bernese, Border Collie r Whippet

How would you diagnose SRMA?

Pyrexia, circulated neutrophils, C-reactive protein, cisternal spinal fluid analysis showing huge neutrophilic pleocytosis

What is the treatment for SRMA?

Immune suppression

What is the prognosis associated with SRMA?

Very food for eventual remission and this is disease that they grow out of, relapse 30%

What is the aetiopathogenesis of atlantoaxial subluxation

Failure of dens to form properly or traumatic fracture causing subluxation of C1-2

What signalment is associated with atlantoaxial subluxation?

Toy breed dogs, usually under. months old at first episode

What is the presentation of atlantoaxial subluxation?

Acute, progressive over 2-3 days, may wax and wane, symmetrical, very painful

What is the treatment for atlantoaxial subluxation?

Splinting may allow eventual stabilisation, surgical fiction may be better

What is the prognosis for atlantoaxial subluxation?

10-20% peri-op mortality, 80% improvement with surgery and 60% with medial management