All Four Limb Conditions

Question 1

Four general causes of tetraparesis/plegia

Answer 1

1. Spinal cord lesions between C1 and T2
2. Muscle and end-plate conditions
3. Neuropathies
4. Brain Conditions

Question 2

Causes: Cervical disc disease

Answer 2

Hansen type 1: typically at C3/4, C5/6, or C6/7

Hansen type 2: typically at C6/7

Question 3

Canine wobbler syndrome

Answer 3

Hansen type 2 prolapse at C/7

Question 4

Signs: Cervical disc disease

Answer 4

Predominantly severe neck pain- may be acute or slowly progressive (hold neck at a fixed position and yelp following minor movements)

Neurological signs due to spinal compression less common than with thoracolumbar (wider canal)

Signs more severe in hind limbs than front

Question 5

Dx: Cervical disc disease

Answer 5

Radiographs- narrowing of disc spaces, mineralized disc material in spineal canal

Myelography to confirm site

CSF- increased cellularity and protein

Question 6

Tx: Cervical disc disease

Answer 6

Cage rest if no neurological deficits with pred/diazepam/methocarbamol to control pain (2wks past resolution of CS)

If no improvement in 2wks- surgical intervention; ventral fenestration or decompression

Prognosis excellent though second surgery may be required

Question 7

Common name: Cervical spondylomyelopathy

Answer 7

Canine Wobblers

Question 8

Causes: Cervical spondylomyelopathy

Answer 8

1. Congenital stenosis of vertebral canal (Dobermans and Great Danes)
2. Hansen type 2 disc protrusion
3. Hypertrophy of ligamentum flavum and joint capsule
4. Bony proliferation of articular processes, pedicles, and/or lamina (Great Danes)

Question 9

Etiology: Cervical spondylomyelopathy

Answer 9

Genetics, congenital spinal canal stenosis, over-nutrition, rapid growth, abnormal vertebral growth (bobble head), congenital ligamentous laxity, abnormal stresses/mobility in synovial joints, Hyperplasia of interarcuate ligament, joint capsules, dorsal longitudinal ligament, and dorsal annulus fibrosis, Hypercalcitonin-induced retardation of osteocytic osteolysis, Intervertebral disc degeneration

R/o Trauma

Question 10

Sings: Cervical spondylomyelopathy

Answer 10

Slowly progressive neurological signs over weeks to months
Cervical hyperesthesia and neck guarding

Hind limbs: Paresis (more pronounced), ataxia, wide based gait, scuffing

Forelimbs: paresis, hypometria, LMN signs absent with atrophy in supra/infraspinatus muscles and decreased flexor withdrawl

Question 11

Dx: Cervical spondylomyelopathy

Answer 11

Signalment ang CS highly suggestive, myelography or MRI

Question 12

Cervical spondylomyelopathy Radiographic findings (5)

Answer 12

1. Tipping of craniodorsal aspect of vertebral bodies
2. Stenosis of vertebral canal
3. Rounding of cranioventral aspect of veterbral body
4. Collapsed disc space
5. Degeneration of articular facets

Question 13

Cervical spondylomyelopathy MRI findings (4)

Answer 13

1. Dorsal cord compression from hypertrophied ligamentum flavum
2. Ventral cord compression from hypertrophied dorsal annulus
3. Lateral cord compression from articular facet malformation
4. Compression from a stenotic vertebral canal or vertebral tipping

25% may be clinically normal
Typically one site in dobermans and multiple sites in great danes

Question 14

Tx: Cervical spondylomyelopathy

Answer 14

Medical therapy will not improve condition: exercise, prednisone

Surgery: best option; decompression, dorsal laminectory and stabilization: recovery in about 2.5m

Survival time the same for both options, prognosis good for prolapsed disc patients

Prognosis poor for tetraplegic, recurrence of clinical signs common

Question 15

Causes: Atlanto-axial subluxation

Answer 15

1. Absence or hypoplasia of odontioid process/dens (most common)
2. Odontoid gracture at ossification center between dens and C2
3. Rupture of ligamentous supports (dorsal atlanto-axial ligament and/or transverse ligament)

Question 16

Signs: Atlanto-axial subluxation

Answer 16

Acute traumatic rupture results in pithing and acute death

Very from neck pain to tetraplegia may be acute or slowly progressive

Question 17

Common COD: Atlanto-axial subluxation

Answer 17

Respiratory paralysis

Question 18

Dx: Atlanto-axial subluxation

Answer 18

Clinical signs and radiography

Question 19

Tx: Atlanto-axial subluxation

Answer 19

Hemilaminectomy and immobilization of subluxation

Question 20

Definition: Syringomyelia

Answer 20

Fluid filled cavitities in the spinal cord as a result of abnormal CSF flow

Question 21

Breed disposition: Syringomyelia

Answer 21

Cavalier king charles, poodles, terriers, pugs

Question 22

Etiology: Syringomyelia

Answer 22

Caudal occipital malformation syndrome (Chiari type 1 malformation in humans) and underdeveloped caudal fossa

Question 23

Signs: Syringomyelia

Answer 23

Impaction of foramen magnum= subtle cerebellovestibular signs

Impaction of the syrix on the dorsal horns= neuropathic pain and scratching, head/neck pain, vocalization, vestibular signs, tetraparesis, sometimes LMN signs to a front limb

Usually progressive

Question 24

Tx: Syringomyelia

Answer 24

Diuretics, omeprazole/cimetidine, prednisone, gabapentin/pregabalin

Craniocervical decompression- 20% relapse

Question 25

Infectious myopathies

Answer 25

Dogs: Neospora, toxoplasma, borrelia, hepatoxoonosis, leptospirosis Cats: Toxoplasma, FeLV, FIV

Question 26

Most common inflammatory myopathy

Answer 26

Autoimmune polymyositis

Question 27

Signs: Autoimmune polymyositis

Answer 27

Generalized weakness, stiff gait, rapid fatigue, generalized muscle atrophy Muscle pain, pyrexia, regurgitation from megaesophagus, dysphonia, dysphagia

Question 28

Dx: Autoimmune polymyositis

Answer 28

Muscle biopsies- necrosis, phagocytosis of myocytes, perivascular lymphocyte and plasma cell infiltration, regeneration and fibrosis Changes in muscle EMG

Question 29

Ddx: Autoimmune polymyositis

Answer 29

Infectious myopathies, paraneoplastic polymyositis

Question 30

Tx: Autoimmune polymyositis

Answer 30

Responsive to immunosupressive doses of prednisone Long-term therapy may be required, give with azothioprine

Question 31

Signalment: Masticatory muscle myositis

Answer 31

Larger-breed dogs under 4yo

Question 32

Signs: Masticatory muscle myositis

Answer 32

Inflammation of the muscle of mastication: swollen, painful esp when opening mouth May be fever, regional lympadenomegally, pseudotrismus, elevated CK, leukocytosis, eosinophlia

Question 33

Cause: Masticatory muscle myositis

Answer 33

Autoimmune humeral response against type 2M muscle fibers

Question 34

Acute: Masticatory muscle myositis

Answer 34

Last 1-3wks

Question 35

Chronic: Masticatory muscle myositis

Answer 35

Severe atrophy of masticatory muscles; difficulty opening mouth due to fibrosis Often have no Hx of acute episodes

Question 36

Dx: Masticatory muscle myositis

Answer 36

Serology or immunohistohemistry of muscle biopsies

Question 37

Tx: Masticatory muscle myositis

Answer 37

Good response to prednisone; may eventually be withdrawn

Question 38

Signalment: Extraocular myositis

Answer 38

Golden retrivers esp, other large breed dogs usually 6-18mo

Question 39

Signs: Extraocular myositis

Answer 39

Bilateral exopthalmus (can be unilateral) Masticatory and limb muscles are notmal

Question 40

Tx: Extraocular myositis

Answer 40

Corticosteroid therapy for a few weeks

Question 41

Exertional myopathy

Answer 41

Typically seen in greyhounds and sled dogs a day or two after a race CS: distressed with painful rigid muscles, elevated CK COD: Renal failure

Question 42

Cause: Hypokalemic myopathy

Answer 42

Older cats with renal disease, low potassium/acidifying diets, hyperthyroidism

Question 43

Signs: Hypokalemic myopathy

Answer 43

Persistant ventroflexion of the neck, stiff, stilted gait, resistance to movement, increased CK

Question 44

Tx: Hypokalemic myopathy

Answer 44

Potassium supplementation

Question 45

Feline idiopathic inflammatory myopathy

Answer 45

Ddx: Inflammatory and hypokalemic myopathy Sudden onset of weakness with pronounced cervical ventroflexion Tx: prednisone

Question 46

Signalment: Limber tail/ coccygeal muscle injury

Answer 46

Pointers, labrador retrievers, other working dogs CS occur after long periods of rest and subsequent hard workouts

Question 47

Signs: Limber tail/ coccygeal muscle injury

Answer 47

Flaccid tail which may be painful Fecal/urinary continence spared

Question 48

Tx: Limber tail/ coccygeal muscle injury

Answer 48

None, recovery within a few days

Question 49

Cause: Dystrophic myopathies

Answer 49

Inherited abnormaitites of the cytoskeleton-dystrophin

Question 50

Signs: Dystrophic myopathies

Answer 50

Progressive condition for ~6mo of age then stabilizes Stunting, weakness, gait abnormalities, trismus, marked muscle atrophy with fibrosis and contracture Kyphosis and lordosis, enlargement of tongue base, and pharyngeal/esophageal dysfunction

Question 51

Tx: Dystrophic myopathies

Answer 51

None, older animals will die of complications

Question 52

Non-Dystrophic myopathies (5)

Answer 52

1. Central core-like myopathies (Great danes) 2. Nemaline rod myopathy (family of cats and blue merle border collie) 3. Centronuclear myopathies (labs) 4. Myofibrillar myopathy with desmin storage (Aussies) 5. Congenital degenerative myopathies (labs, bouviers, chows, retreivers)

Question 53

Metabolic myopathies (4)

Answer 53

1. Hypothyroidism 2. Hyperthyroidism 3. Hyperadrenocorticism 4. Various Enzyme deficiencies