Neurology 1 Flashcards
What are 6 tests you should perform (general) when evaluating an animal with a neuro condition involving one limb?
- Observe mental status, gait, and posture
- Palpate muscular and skeletal systems
- Evaluate postural reactions
- Evaluate cranial nerves
- Evaluate spinal nerves
- Evaluate sensation
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
General terms:
- Paresis
- Plesia
- Hypesthesia
- Paresis = decreased motor activity
- Plesia = paralysis (no movement whatsoever)
- Hypesthesia = decreased sensation in the limb
What is this an example of?
Radial nerve paralysis
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
What are the general signs of a peripheral nerve injury?
Hyp/anesthesia, decreased reflexes
PE may have lack of sensation, hypesthesia, LMN signs
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)
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
What are the causes of brachial plexus avulsion?
- Trauma–abducts caudally/cranially
- Avulsion–stretching of nerve roots (C6-T2)
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
What is this a typical example of?
Brachial plexus avulsion
T/F: If a brachial plexus avulsion occurs from damage to T1, the animal can present with Horner’s syndrome as well.
TRUE
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%)
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
What are the signs of nerve root/peripheral nerve neoplasia?
- Prog. monoparesis
- Atrophy
- “Root sign”–hyperpathia with limb palpation or manipulation
How do you diagnose nerve root/peripheral nerve neoplasias?
- Myelo, CT, MRI–site/size of tumor
- Histopathology–surgery
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
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
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
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
