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Flashcards in Small animal neurological conditions Deck (52)
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1
Q

What can lesions in LMN cause?

A

loss of reflex, loss of voluntary control, atonia, flaccid paralysis, rapid muscle atrophy

2
Q

What can lesions in UMN cause?

A

oss of “calming effect”; loss of voluntary control; reflex intact and may be hyperactive, hypertonia, spastic paralysis.

3
Q

What are the main causes of spinal cord dysfunction?

A

Compression

Contusion

Laceration

Ischaemia

Inflammation

4
Q

From grade 1-5, what are the clinical signs for each grading?

A

1 - spinal pain

2 - Paresis (ambulatory)

3 - Non-ambulatory paresis

4 - Paralysis

5 - Paralysis with absence of pain perception

5
Q

How could you treat spinal cord lesions?

A

Surgical decompression

Appropriate treatment for infection / inflammation

Physical rehabilitation

6
Q

Define tetraparesis

A

reduced voluntary motor function in all 4 limbs

7
Q

Define tetraplegia

A

total absence of voluntary motor function in all 4 limbs.

8
Q

What clinical signs will you see in cervical spondylomyelopathy?

A

Progressive ataxia

Tetraparesis

Neck pain

9
Q

What can cause cervical spondylomyelopathy?

A

Progressive spinal cor compression

Can be result of congenital stenosis and degenerative changes in the vertebral column

10
Q

How would you treat cervical spondylomyelopathy?

A

Surgery for patients with neurological deficits (to decompress/stabilise) the cervical spine.

Medical includes treatment of pain, restriction of unmonitored activity and controlled exercise/physical therapy.

11
Q

Describe intervertebral discs

A

Intervertebral discs are fibrocartilagenous cushions between the vertebra

Outer rim (annulus fibrosus) and inner ‘jelly like’ centre (nucleus pulposus).

Allow movement, support and act as shock absorbers

12
Q

Describe acute cervical disc disease (Hansen type I)

A

Hansen Type I; chondroid degeneration of nucleus pulposus; either bulges into spinal canal – progressive disease

or

Dorsal extrusion through annulus fibrosus - acute spinal trauma

13
Q

What breeds is acute cervical disc disease common in (Hansen type I)?

A

Shih tzu

Dachsunds

Pekingese

Beagles

14
Q

What are the clinical signs of acute cervical disc disease (Hansen type I)?

A

severe neck pain; head held down, rigid neck, back arched (transfer weight to pelvic limbs)

15
Q

What neurological signs may be seen in acute cervical disc disease (Hansen type I)?

A

tetra/hemi paresis/plegia, ataxia, proprioceptive and postural deficits.

16
Q

Describe the pathogenesis of acute cervical disc disease (Hansen type I)

A

nucleus pulposus (gelatinous) premature aging in chondrodysplastic breeds

Hansen Type I disease

C2-C3 most commonly affected in small breeds

C6-C7 in large breeds

17
Q

How would you diagnose acute cervical disc disease (Hansen type I)?

A

Clinical signs

Diagnostic imaging

18
Q

Describe medical management of acute cervical disc disease (Hansen type I)

A

Pain relief and strict cage rest (4 weeks). Aim of cage rest is to allow annulus fibrosus to heal.

If neck pain ↓ gradual reintroduction to exercise

If pain persists or returns or neurological deficits are present requires surgery.

19
Q

Describe surgical treatment of acute cervical disc disease (Hansen type I)

A

Ventral slot (to remove extruded material) with fenestration of adjacent discs (opening into annulus)

Post surgery; pain relief & confinement for 4 weeks (2 weeks cage rest; 2 weeks progressive return to exercise)

Physiotherapy

20
Q

Describe acute cervical disc disease (Hansen type II)

A

Fibrinoid degeneration of nucleus pulposus and protrusion of annulus fibrosus (hypertrophy) into spinal canal

More common

21
Q

What animals are more prone to acute cervical disc disease? (Hansen type II)

A

More common in older, non-chondrodystrophic dogs

22
Q

What are the clinical signs of acute cervical disc disease? (Hansen type II)

A

chronic, slowly progressive signs. Spinal pain may or may not be evident

Neurological deficits often less severe than with type 1 disease.

23
Q

Describe treatment for acute cervical disc disease (Hansen type II)

A

conservative in milder cases, surgery indicated when neurological deficits are more severe.

24
Q

Describe acute cervical disc disease (Hansen type III)

A

Explosion of the nucleus pulposus from a sudden tear in the annulus typically associated with heavy exercise or trauma.

Aka High velocity low volume extrusion

25
Q

Describe tretraparesis caused by atlantoaxial instability

A

Instability of atlas and axis junction

Congenital form – onset of signs most commonly seen in dogs less than 2 years age

Trauma

26
Q

What are the signs of Atlantoaxial Instability?

A

neck pain (waxing and waning), ataxia, tetraparesis, postural and proprioceptive deficits

normal or increased myotactic reflexes/ muscle tone

27
Q

How would you treat Atlantoaxial Instability?

A

Medical; for those cases with mild signs

External splint for 6 weeks – to stabilise and allow ligaments to heal

Surgical management; required if neurological deficits present

Stabilisation of atlanto-axial junction – screws, pins etc.

28
Q

What are the two common causes of traumatic spinal injury?

A

fractures and luxations.

29
Q

Describe medical and surgical management of a traumatic spinal injury

A

Medical management – splints / cage rest

Surgical management – spinal stabilization

30
Q

Describe tetraparesis caused by Fibrocartilagenous embolism (FCE)

A

Signalment; Peracute onset of non-painful neurological deficits

Usually large, young non-chondroplastic breeds – commonly at lumbosacral intumescence

Also smaller breeds represented; Shetland Sheepdog, Miniature Schnauzer, Yorkshire Terrier – usually C6-T2

31
Q

What is the pathogenesis of FCE?

A

fibrocartilagenous embolism from spinal structure – spinal blood vessel blocked– ischaemic necrosis of spinal cord grey matter.

32
Q

State the clinical signs of FCE

A

often lateralised – hemiparesis

May get Horner’s Syndrome (sympathetic system affected) and vasodilation on the affected side (up to 10°C warmer)

33
Q

What are two bacterial causes of tetraparesis?

A

Tetanus (Clostridium tetani)

Botulism (Clostridium botlulinum)

34
Q

Describe paraparesis

A

Most common cause is disease of the thoracolumbar spine.

Clinical signs dependent on where cord is affected; T3-L3 or L4-S3.

35
Q

What complications can occur from an acute severe spinal cord injury?

A

Neurogenic shock

Spinal shock

36
Q

Describe neurogenic shock

A

Sympathetic ns dysfunction (with parasympathetic function) – decreased blood pressure, heart rate – may lead to ischaemia – kidney failure

Present in humans; rarely clinically in dogs/cats

37
Q

Describe spinal shock

A

Flaccidity caudal to the lesion – decreased spinal reflexes

38
Q

Describe paraparesis caused by degenerative myelopathy

A

Insidious, progressive ataxia and paresis of pelvic limbs progressing to paraplegia

Initially recognised in GSD, but other breeds as well

Average age of onset – 9 years

39
Q

What are the signs of degenerative myelopathy?

A

early; general porprioceptive ataxia and mild spastic paresis of pelvic limbs; worn nails on pelvic limbs

most large breed dogs progress to non-ambulatory within 6 – 9 months

Late stage – LMN signs in pelvic limbs and UMN signs in thoracic limbs; eventually tetraplegia

Severe muscle atrophy

40
Q

What are the treatment options for degenerative myelopathy?

A

non-specific. Poor prognosis. Physiotherapy and hydrotherapy may help manage the condition (maintenance of muscle strength) and associated with longer survival.

41
Q

Describe paraparesis caused by Type I Hansen disc disease

A

Back pain, kyphosis, reluctance to walk

Paraplegia, reduction in nociceptor responses

In small breeds most commonly at T12-T13; in Large Breeds mainly L1-L2

42
Q

Describe treatment for Type I Hansen Disc disease (paraparesis)

A

Medical management; for mild spinal pain -as per cervical lesions

Surgical management;

Spinal cord decompression

Dorsal laminectomy

Hemilaminectomy (lateral approach) + fenestration

Post surgical management as per cervical lesions

43
Q

Describe monoparesis

A

Monoparesis / plegia?

Nerve Root Signature = pain manifested as lameness due to nerve root irritation / compression

44
Q

What nerves can cause monoparesis?

A

Brachial plexus- network of nerves innervating the forelimb (arise from spinal nerves C6-T2).

Lumbosacral plexus- network of nerves innervating the hindlimb (arise from L4-S3 in the spinal cord).

45
Q

Define neuropraxia

A

interruption of nerve conduction without physical disruption of the axon.

46
Q

Define axonotemesis

A

physical interruption of the axon.

47
Q

Define neurotemesis

A

complete severance of the nerve- most severe type of injury.

48
Q

Describe foraminal stenosis

A

Narrowing of foramen where nerve roots exit

LMN signs localised to one or more nerve roots

Nerve root signature;

pain on manipulation or palpation of affected limb

Lameness of affected limb – may avoid weight-bearing

May be constant, intermittent or exacerbated by exercise

49
Q

Describe treatment for foraminal stenosis

A

Medical management; NSAIDs and pain relief (but often signs return)

Surgical; dorsal laminectomy and/or foraminotomy

50
Q

Describe brachial plexus avulsion

A

RTAs, fall from height – adduction and caudal displacement of thoracic limb

Acute onset; either

Cranial avulsion (C6-C8 nerve roots)

Caudal avulsion (C8-T2)

Complete avulsion (C6-T2)

51
Q

What are the clinical signs of brachial plexus avulsion?

A

Cranial is rare and few clinical signs;

Atrophy of supra/infraspinatus

Loss of shoulder flexion/extension; loss of elbow flexion. Can bear weight.

Caudal and Complete more common and more severe signs;

Loss of elbow extension (triceps brachii) – no weight-bearing and drags limb with carpus knuckled.

Severe neurogenic atrophy

Caudal alone – flexor muscles work therefore tends to carry limb

52
Q

Describe treatment for brachial plexus avulsion

A

Non-specific – physiotherapy and keep limb clean and protected

Cranial avulsions can bear weight and have a good prognosis

Complete/caudal avulsions – poorer prognosis; depends on severity of nerve damage.

May require limb amputation