8 – Neuro 1

Question 1

Localize the lesion of a clinically significant region: 4 general categories

Answer 1

1. Brain
   a. Cerebrum, cerebellum, brainstem
2. Vestibular
   a. Central and peripheral
3. Spinal cord
   a. C1-C5, C6-T2, T3-L3, L4-S2
4. Peripheral NS
   a. Nerve, muscle, NMJ junction

Question 2

What are the categories of differential diagnoses based on onset and progression of disease? (DAMNIT-V P)

Answer 2

• Degenerative
• Anomalous (congenital)
• Metabolic
• Neoplastic/nutritional
• Idiopathic/inflammatory
• Toxin/traumatic
• Vascular
• Parasitic (ex. a hunting dog=would be higher)

Question 3

What is the 5-step approach to solving neurologic problems?

Answer 3

• Neuro exam (already did a through physical exam)
• Localize the lesion
• Characterize onset and progression
• Generate DDx list
• Use ancillary tests to make diagnosis

Question 4

Neurological exam: general

Answer 4

• Complete and accurate neurological assessment
• *requires practice and cooperative patient (and handler)

Question 5

What are the 6 components of a neurological exam?

Answer 5

1. Mentation
2. Gait and posture
3. Cranial nerves
4. Proprioception
5. Spinal reflexes, muscle tone, muscle size
6. Sensation and pain

Question 6

Mentation

Answer 6

• Alert
• Dull (ex. a 15 week old puppy)
• Quiet, alert, responsive
• Obtunded: laterally recumbent and or can’t maintain posture
  o Can be aroused with stimulus
• Stuporous: Can’t be aroused by pain or stimulus
• Coma: Non responsive to anything

Question 7

Gait

Answer 7

• Paretic
• Ataxic
• Lame
• *does it look normal or abnormal?

Question 8

Posture

Answer 8

• Weight equally distributed
• Tail up (for most part)
• Head up
  o Is the head turned? Tilted?
• Are they leaning? Falling?

Question 9

Pain

Answer 9

• Have limb flexed
  o Just because they move doesn’t mean they feel pain, maybe the reflex arc is just still intact

Question 10

Paresis

Answer 10

• Decrease in voluntary motor movements

Question 11

Plegia or paralysis

Answer 11

• NO voluntary motor movements

Question 12

Thorax limbs reflex

Answer 12

• Withdrawal reflex
  o MOST reliable in forelimbs

Question 13

Pelvic limb reflex

Answer 13

• Patellar
• Withdrawal
• Cranial tibial

Question 14

If seizure, where is it from?

Answer 14

• Cerebrum!!

Question 15

If multiple CN signs?

Answer 15

• Brainstem

Question 16

If vestibular signs?

Answer 16

• Brainstem

Question 17

Ventral vs. dorsal roots

Answer 17

• Ventral: motor
• Dorsal: sensory

Question 18

Proprioception

Answer 18

• Ability to sense where the limbs are in space
• Usually do it with some weight support
• Even minor damage to ascending proprioceptive tracts results in LOSS of proprioception in limbs CAUDAL TO LESION

Question 19

UMN vs. LMN

Answer 19

• UMN: originates in brain and controls the LMN
  o *brainstem and (cortex)
  o Initiate/control movement, regulate normal extensor tone
• LMN: neuron connecting the CNS to the muscle

Question 20

UMN signs

Answer 20

• Long, spastic gait
• Normal or exaggerated spinal nerve reflexes
• Increased muscle tone
• **delayed postural reactions
  o NOT involved in postural reactions, but are typically damaged together causing paresis AND proprioceptive deficits simultaneously
• Bladder: hard to express, enlarged

Question 21

LMN signs

Answer 21

• Short and choppy gait
• Decreased spinal nerve reflexes
• Decrease muscle tone
• Normal to delayed postural reactions
• Bladder: large, easily expressed bladder (flaccid)=urine leaks out

Question 22

UMN signs to all limbs CAUDAL to the lesion

Answer 22

• Loss of proprioception, ataxia
• Decreased motor function: paresis/paralysis
• Increased extensor muscle tone
• *increased reflexes
• Gait: base wide stance, excess limb abduction when during, long strides

Question 23

Spinal tracts cross midline ROSTRAL to brainstem

Answer 23

• If lesion in SC= UMN signs in ipsilateral limbs
• If lesion in brainstem=UMN signs in ipsilateral limbs
• **If lesion in cerebral cortex=deficits in CONTRALATERAL LIMBS

Question 24

LMN components

Answer 24

• Nerve cell bodies in grey matter
  o Nerve roots
  o Spinal nerves
  o Peripheral nerves
• NMJ
• **damage to any component causes LMN signs in muscles/limbs directly supplied by that LMN=AT THE LEVEL of the lesion

Question 25

L4,5,6 nerve / reflex

Answer 25

• Femoral nerve
  o *patellar reflex
  o Quadriceps muscle

Question 26

L6-S2 nerve / reflex

Answer 26

• Sciatic nerve
  o Flexor muscles of rear limb
  o *withdrawal reflex

Question 27

S1-S3 components/tone

Answer 27

• Anus
• Bladder

Question 28

C1 to C5

Answer 28

• UMN to all 4 limbs (or the 2 limbs on the same side)
• Normal mentation
• Limb reflexes=intact
• Slight increase in tone
• Sometimes Horner syndrome

Question 29

C6 to T2

Answer 29

• Normal mentation
• Decreased reflex in thoracic limbs
• Normal to increased reflexes in pelvic limbs

Question 30

T3 to L3

Answer 30

• Only UMN of back legs affected
• Normal mentation
• Normal thoracic limbs

Question 31

L4 to S3

Answer 31

• Normal mentation
• Normal thoracic limbs
• Normal to decreased reflexes and tone to pelvic limbs

Question 32

Focal LMN nerve roots, nerves: Lymphoma involving nerve roots/spinal nerves supply the pelvic limb (L4-S2)

Answer 32

• LH atrophy
• LH weakness
• Loss of reflexes in LH
• Loss of sensation LH
• RH normal
• Anal tone normal

Question 33

Generalized LMN

Answer 33

• Inflammation of all ventral nerve roots (LMNs) as they leave the spinal canal
  o ‘allergic neuritis’
• Profound motor weakness or paralysis of all 4
• Loss of reflexes
• Normal sensation