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Flashcards in Neurology 1 Deck (21):
1

What are 6 tests you should perform (general) when evaluating an animal with a neuro condition involving one limb?

  1. Observe mental status, gait, and posture
  2. Palpate muscular and skeletal systems
  3. Evaluate postural reactions
  4. Evaluate cranial nerves
  5. Evaluate spinal nerves
  6. Evaluate sensation

2

What are the 3 general terms for traumatic nerve injuries, and what does each one mean?

  • Neuropraxia
    • Least severe
    • Assoc. w/ cutting off blood supply (like your foot falling asleep)
    • Important in large animals during/after surgery
  • Axonotmesis
    • Nerves can regenerate as long as cell body is still intact--axon is still in place
    • Grows about 1 mm/day; just give some time and see how it progresses
  • Neurotmesis
    • Worst
    • Myelin sheath is damaged--> axon can regenerate but doesn't know where to go--> irreversible damage
    • Nerve won't be used again

3

General terms:

  • Paresis
  • Plesia
  • Hypesthesia

  • Paresis = decreased motor activity
  • Plesia = paralysis (no movement whatsoever)
  • Hypesthesia = decreased sensation in the limb

4

What is this an example of?

Radial nerve paralysis

5

Why are these kitties so sad? :( What is it often a side effect of, and can they recover?

They have sciatic nerve damage

Often seen in cats with diabetes; nerve function can return, but takes a long time

6

What are the general signs of a peripheral nerve injury?

Hyp/anesthesia, decreased reflexes

PE may have lack of sensation, hypesthesia, LMN signs

7

How do you diagnose a peripheral nerve injury?

  • History--some sort of trauma 
  • LMN signs
    • Dec. flexia, dec. tonicity, atrophy, dec. esthesia
  • EMG changes (not really helpful clinically)

8

What are the treatments for peripheral nerve injury?

  • Must protect limb--constantly replace bandages (to prevent self-trauma)
  • Glucocorticoids to treat inflamation 
    • More harmful than helpful--chew up proteins--> gluconeogenesis
  • Physiotherapy
    • VERY IMPORTANT
    • 15 minutes, 3x a day (minimum)
    • If not better in 6 months, won't ever get better
  • Transplant + arthrodesis - amputate - 6 months

9

What are the causes of brachial plexus avulsion?

  • Trauma--abducts caudally/cranially
  • Avulsion--stretching of nerve roots (C6-T2)

10

What are the various signs for brachial plexus avulsion?

  • C6 + C7 = ext/flex shoulder
  • C8 + T1 = ext/flex - elbow/carpus
  • C8 and T1 = lat thor n. - decreased panniculus reflex
  • T1 ventral n. roots = pregang symp - Horner's 

11

What is this a typical example of?

Brachial plexus avulsion

12

T/F: If a brachial plexus avulsion occurs from damage to T1, the animal can present with Horner's syndrome as well.

TRUE

13

What is the diagnosis for brachial plexus avulsion? Treatment?

  • Diagnosis
    • History, clinical signs
  • Treatment
    • Protect, physiotherapy
    • Amputate--6 months
    • Prognosis generally poor
      • Pain predicts recovery--if animal has pain, often gets better (70%)

14

What are some examples of nerve root/peripheral nerve neoplasia?

  • Sheath tumors (MPNST) [neurofibromas/schwannomas] caudal cervical area (brachial plexus) 80%
    • All act the same--malignant, invasive, bad news
    • Peripheral nerve, into sc.
  • Meningiomas, lymphomas, bony/soft
    • Compress, invade peripheral nerves

15

What are the signs of nerve root/peripheral nerve neoplasia?

  • Prog. monoparesis
  • Atrophy
  • "Root sign"--hyperpathia with limb palpation or manipulation

16

How do you diagnose nerve root/peripheral nerve neoplasias?

  • Myelo, CT, MRI--site/size of tumor
  • Histopathology--surgery 

17

What are these examples of? How do you treat them?

Nerve root neoplasia

  • Resection is best
    • Often involves decreased function + recurrence (can't get all the cancerous cells out)
  • Radiation and chemotherapy +/-
    • Might give an extra month or two

18

What are some examples of fibrocartilaginous emobli?

  • Fat/septic/thrombi
    • Fibrocartilage most NB in neural injury (intervertebral discs)
    • Pathway not understood
  • Ischemic myelopathy
    • Blocks blood vessels in spinal cord

19

What are the signs of fibrocartilaginous emboli/ischemic myelopathy?

  • Large/giant breeds 3-6 y
  • Small breeds--mini Schnauzers
  • Signs peracute
    • 60% post/during exercise
  • No trauma, non-progressive (+/- 6 hr)
  • Paresis/paralysis--lateralizing
  • Not painful after initial event
  • Often--brachial/pelvic intumescence--LMN signs

20

How do you diagnose ischemic myelopathy?

  • Diagnosis of exclusion (without MRI)
  • History, clinical signs
  • Exclusion of inflammatory, compressive sc diseases
  • Myelography--usually normal, maybe swollen spinal cord
  • MRI--esp. non-ambulatory cases
  • X-rays rule out fractures

21

What is the treatment for ischemic myelopathy?

  • No specific treatment--boils down to nursing care
  • Acute--dex/methylpred (shock)? PG?
  • Supportive therapy
    • Rest, clean, sleep, physio therapy
  • UMN bladder--phenoxy, prazosin (blocks alpha receptors), tamsulosin
    • Urocholine PPE
  • No evidence that steroid therapy is useful
  • Some improve (usually < week - UMN)
  • Some don't improve (65%/ 22%) - LMN
  • Residual defects (30%)