One Limb Conditions

Question 1

Nerve root signs

Answer 1

lameness due to stretching/inflammation of nerve roots eg. from disc protrusion or pressure from a tumor.

Question 2

Neuropraxia

Answer 2

The best kind of nerve damage.

Loss of blood supply with no degeneration of nerves. Myelin sheaths may degenerate.

Recovery in days to months.

Question 3

Axonotmesis

Answer 3

Degeneration of axons without damage to endoneurium and Schwann cells. Axons regenerate 1mm/day.

Paresis and Hypesthesia

Question 4

Neurotmesis

Answer 4

Complete shearing/degeneration of a nerve. Regeneration will usually not occur.

Question 5

Signs: Peripheral Nerve Injury

Answer 5

Anesthesia, absence of reflexes controlled by affected nerve, marked/rapid muscle atrophy (non-progressive LMN signs).

Question 6

Dx: Peripheral Nerve Injury

Answer 6

History, Symptoms, Loss of muscle potential on EMG, development of spontaneous muscle activity (7-10days)

Question 7

Tx: Peripheral Nerve Injury

Answer 7

Primary: Glucocorticoids, Protect limb, decompression if necessary

Secondary: flexor tendon transplantation and arthrodesis

All else fails: limb amputation

Question 8

Causes: Peripheral Nerve Injury

Answer 8

HBC, Intra-muscular injections, trauma

Question 9

Causes: Brachial Plexus Avulsion

Answer 9

Abduction trauma stretching C6-T2

Question 10

Signs: Brachial Plexus Avulsion

C8-T1

Answer 10

Denervation of extensors/flexors of the elbow and carpus

Question 11

Signs: Brachial Plexus Avulsion

C6-C7

Answer 11

Denervation of extensors/flexors of the shoulder

Question 12

Signs: Brachial Plexus Avulsion

T1

Answer 12

Horner’s Syndrome- sympathetic denervation of the eye

miosis, ptosis, endopthalmos, protrusion of nictitating membranes

Question 13

Dx: Brachial Plexus Avulsion

Answer 13

History, clinical signs, EMG

Question 14

Tx: Brachial Plexus Avulsion

Answer 14

Primary: Protect affected limb, physiotherapy

Amputation if no improvement within 6mo

Guarded prognosis- presence of deep pain is the best predictor

Question 15

Signs: Nerve root/peripheral nerve neoplasia

Answer 15

Chronic progressive monoparesis with neurogenic muscle atrophy, hyperesthesia

50% cervical malignant peripheral nerve sheath tumors have pelvic signs

Question 16

Nerve sheath tumor types and location

Answer 16

Neurofibromas/sarcomas, Schwannomas/malignant peripheral nerve sheath tumors

80% caudal cervical area associated with brachial plexus- start peripheral and spread proximal to spinal cord

Question 17

Dx: Nerve root/peripheral nerve neoplasia

Answer 17

Clinical signs, History, Myelograms, CT/MRI

Definitive: histopathy of samples

Question 18

Cause: Fibrocartilagenous Emboli

Answer 18

Seem to originate from nucleus pulposis and move to spinal cord via the circulatory system causing ischemic encephalopathy.

Question 19

Signs: Fibrocartilagenous Emboli

Answer 19

Peracute paresis/paralysis usually lateralizing, non-painful,

Usually involve brachial or pelvic intumescence- LMN deficits

Question 20

Fibrocartilagenous Emboli Predisposed Breeds

Answer 20

1-7yo Large breeds most commonly, mini schnauzers, during or after vigorous exercise

Rare in cats- usually cervical, not exercise associated

Question 21

Dx: Fibrocartilagenous Emboli

Answer 21

Signalment, History, Clinical Signs, MRI in severe cases

Exclusion of inflammatory compressive disease via myelography/CSF examination

Question 22

Tx: Fibrocartilagenous Emboli

Answer 22

Dexamethasone- reduce edema/inflammation
Supportive therapy, cage rest, bladder expression, physiotherapy

Prognosis better for dogs w/ UMN signs

Recovery typically in 1-4mo; may still have deficits