10 – Neuro II

Question 1

Mentation: what are you looking for?

Answer 1

• BAR (bright, alert and responsive)
• QAR (queit AR)
• Dull/depressed
• Obtunded: can be roused by noise or noxious stimulus
• Stuporous: laterally recumbent
• Coma: not conscious
• Behavior
  o Aggression, loss of learned behaviours, anxious/restless, hiding

Question 2

What are ‘signs’ of an ipsilateral vestibular problem?

Answer 2

• Head tilt
• Falling
• Head turn

Question 3

What is a broad based stance a ‘sign’ of?

Answer 3

• Proprioceptive deficit / paresis = UMN

Question 4

What is a narrow based stance a ‘sign’ of?

Answer 4

• Proprioceptive deficit / paresis = LMN

Question 5

What is palmigrade/plantigrade posture a sign of?

Answer 5

• Paresis = LMN

Question 6

What can increased tone (UMN/cerebellar) show up as in terms of posture?

Answer 6

• Opisthotonus: neck in dorsal flexion (brainstem lesion)
  o Stupor, obtund or coma
  o Mentally inappropriate
• Schiff-Sherrington: rigid thoracic limbs with flaccid pelvic limbs (ACUTE, severe spinal cord injury=no communication between border cells) (spinal cord lesion=brain should be NORMAL)

Question 7

Gait : 3 abnormalities

Answer 7

• Lame: pain, musculoskeletal
• Paresis (weak): metabolic, muscle disease, UMN or LMN, myasthenia (NMJ)
• Ataxia/incoordination: UMN vs. LMN

Question 8

Ataxia/incoordination: UMN vs. LMN

Answer 8

• Pathways relaying sensory info to brain or brain regulatory centers have been DISTRUPTED and there is loss or regulation of movement
  o SC/brainstem/peripheral: proprioceptive loss, ataxia
  o Vestibular: loss of balance
  o Cerebellum: loss of fine motor control / hypermetria

Question 9

LMN: weak gait

Answer 9

• Weakness, paresis, exercise intolerance
• Short strided, maintains feed under center of gravity
• May be plantigrade
• *muscle atrophy=rapid
• *loss of reflexes
• *damage to SC grey matter, ventral nerve roots, or peripheral nerves

Question 10

How can we differentiate muscle disease weakness from LMN disease?

Answer 10

• Normal reflexes
• No proprioceptive deficits (ataxia)
• Muscle pain=common

Question 11

Ataxia and UMN involved: what are the 3 ‘areas’ of damage?

Answer 11

• Spinal cord UMN: “long tracts”
• Vestibular system
• Cerebellum

Question 12

UMN: spinal cord/proprioceptive ataxia

Answer 12

• *Decrease proprioception
• *Increased extensor muscle tone
• *normal to increased reflexes
• Long, spastic stride
• Delay in onset of swing phase
• Abnormal postural reactions (knuckling, hopping)

Question 13

UMN: vestibular ataxia

Answer 13

• Loss of balance
• Head tilt, nystagmus
• *proprioception NORMAL if peripheral vestibular
• *proprioception SLOW or absent if brainstem is involved (central vestibular)

Question 14

UMN: cerebellar ataxia

Answer 14

• Hypermetria
• Wide based stance
• Truncal swaying
• Normal strength
• Normal proprioception
• Goose-stepping
• Intention tremor (when trying to do something, ex. eat=gets worse)

Question 15

What does damage or multiple CN signs suggest?

Answer 15

• Brainstem disease
• *ipsilateral signs=do not cross over

Question 16

Hopping: postural reaction

Answer 16

• Support weight and hop on one leg
• LEAN laterally so that center of gravity is NOT over limb
  o Should ‘hop’ to replace the limb under the center of the body

Question 17

Postural reactions

Answer 17

• Abnormal with UMN lesions in SC, brainstem +/- cerebral cortex
• LMN lesions do NOT usually affect conscious proprioception tests UNLESS there is severe sensory loss or loss of voluntary motion
• *used to decide if each limb is neurologically normal or abnormal (the use reflexes to confirm UMN vs. LMN)

Question 18

Spinal reflexes grading

Answer 18

• +2: normal
• +1: diminished
• 0: absent
• +3 :increased
• *normal to increased (+2 to +3) reflexes in UMN disease
• *decreased (0 to +1) in LMN disease

Question 19

Thoracic limb withdrawal: SC segments

Answer 19

• C6 -T2
• Decreased: brachial plexus injury (C6-T2 SC)=LMN
• Normal to increased: SC lesion above C6=UMN

Question 20

Patellar reflex:

Answer 20

• L4-L6
• *femoral nerve
• Increased with lesion b/w brain and L4-L6
• Decreased with lesion of L4-L6 SC segments, nerve roots and femoral nerve

Question 21

Pelvic limb withdrawal: SC segments

Answer 21

• L6-S2
• *sciatic nerve: flexor muscles
• Normal to increased: lesion cranial to L6
• Decreased: lesion of L6-S2, nerve roots, sciatic nerve
• Does NOT indicate the animal can consciously feel anything

Question 22

Perineal reflex: SC segments

Answer 22

• S1-S3

Question 23

Panniculus/cutaneous trunci reflex

Answer 23

• HELPS to further localize a T3-L3 lesion
• *both left and right sides should contract if intact
• If not intact=unilateral or bilateral OR just can’t feel it

Question 24

Muscle tone

Answer 24

• Evaluate each limb NON-WEIGHT BEARING
  o Normal vs. increased vs. decreased

Question 25

Sensation

Answer 25

• Evaluate superficial sensation if there is FOCAL LMN disease
• *dermatome analgesia allows precise localization of nerves affected

Question 26

Testing for deep pain

Answer 26

• *only test when the animal can NOT walk!
• Do at END of exam
• Don’t mistake a reflex for them being able to feel the pain