Large Animal Nervous System Examination

Question 1

what is the purpose of the systemic nervous system exam?

Answer 1

determine presence of neurologic disease
characterize type and degree of deficits
localization of lesion
determine etiology of neurologic disease

Question 2

what do you look at during the sensorium (observational portion) of the exam?

Answer 2

mentation
behavior

Question 3

what are some things that suggest a lesion in the limbic system?

Answer 3

aggression
hyperexcitability
rage
mania
frantic motor activities

Question 4

what does dullness, depression, or stupor suggest?

Answer 4

disease affecting cerebrum or ascending reticular activating system in the brain stem

Question 5

seizure is a manifestation of ___________________ dysfunction

Answer 5

cerebral cortical

Question 6

how does manifestation of dysfunction of the optic nerve present?

Answer 6

impaired menace and papillary light reflex (PLR)

Question 7

how does dysfunction manifest with the trochlear nerve (CN IV)?

Answer 7

dorso-lateral strabismus (extorsion)

Question 8

what cranial nerve(s) run through the lateral guttural pouch?

Answer 8

cranial nerve VII

Question 9

what type of reflex is the menace response?

Answer 9

cortical reflex: involves cortical integration and interpretation

Question 10

how can you recognize cortical blindness versus peripheral blindness?

Answer 10

both have absent menace
cortical has normal papillary light reflexes, peripheral has abnormal papillary light reflexes

Question 11

what are the clinical signs of peripheral vestibular disease?

Answer 11

circling
normal mentation, but disoriented
head-tilt toward side of lesion
CN VII paralysis may be present
horizontal or rotary nystagmus
generally no GP or postural reaction deficits

Question 12

how can you test the vagal nerve (CN X)?

Answer 12

slap test: laryngeal adduction test

Question 13

what does the slap test test the integrity of?

Answer 13

cervical and thoracic spinal cord segments
nucleus ambiguus of medulla
cranial nerve X: laryngeal recurrent nerve

Question 14

what should you look at during the standing exam?

Answer 14

cervico-auricular reflex
cutaneous muscle reflexes
tail and anal tone

Question 15

what do the anal and perineal reflexes evaluate?

Answer 15

caudal rectal/coccygeal/internal pudendal nerves
sacral spinal cord segments

Question 16

what should you check in recumbency?

Answer 16

patella reflex
muscle tone
withdrawal-flexor: do last

Question 17

the degree of functional limb deficits will determine the need for __________________________

Answer 17

postural reaction testing

Question 18

how do we test neurologic dysfunction of the upper motor neuron, lower motor neuron, and general proprioceptive systems?

Answer 18

circling, backing, swaying
head elevation
working on a hill/gentle slope
changes in direct when horse turned loose in paddock
blindfolding

Question 19

what can ataxia be due to?

Answer 19

vestibular
general proprioceptive
cerebellar

Question 20

where do lower motor neurons terminate?

Answer 20

neuromuscular junctions

Question 21

where might lower motor neuron deficits be related to lesions in?

Answer 21

spinal cord segment at the level of the reflex arc
peripheral nerves
neuromuscular junction
muscle

Question 22

what are the clinical signs of moderate to severe weakness with lower motor neuron paresis?

Answer 22

short stride, toe dragging
muscle fasciculation
difficulty supporting weight
weakness in both standing and walking tail-pull exam
decreased spinal reflexes
decreased muscle tone
atrophy of the denervated muscle

Question 23

where do cell bodies of upper motor neurons lie?

Answer 23

within brain

Question 24

what are the clinical signs of upper motor neuron dysfunction?

Answer 24

normal to increased spinal reflexes, increased muscle tone
stiffness, spasticity
paresis: delay in onset of protraction of limb, weakness during tail-pull at a walk

Question 25

most of the upper motor neuron pathways necessary for gait generation are anatomically adjacent to _____________________________

Answer 25

general proprioceptive pathways

Question 26

what does the general proprioceptive system transmit limb and trunk position information to?

Answer 26

cerebellum some to cerebrum for conscious proprioception

Question 27

when is circumduction best seen?

Answer 27

outer limb while circling

Question 28

what are the clinical signs of general proprioceptive ataxia?

Answer 28

stumbling, knuckling, dragging dog sitting while backing circumduction adduction or abduction of limbs, interference between limbs pivoting abnormal stride length ataxic response during walking tail pull

Question 29

what does the cerebellum regulate?

Answer 29

motor activity

Question 30

what is limb movement like with cerebellar disease?

Answer 30

excessive rate, range, and force

Question 31

what is the limbic system?

Answer 31

assembly of connected groups of neurons and neuronal tracts in the cerebrum, thalamus, hypothalamus, and midbrain that is involved in emotional responses and patterns in behavior

Question 32

how does dysfunction of the trigeminal nerve (CN V) manifest?

Answer 32

abnormal palpebral reflex and facial sensation poor jaw tone ability to close mouth

Question 33

which cranial nerves are associated with the mesencephalon?

Answer 33

CN III and IV

Question 34

what makes up the afferent arm of the menace response?

Answer 34

retina optic nerve axons and optic tract and radiations

Question 35

what does vitamin A deficiency cause with menace and pupillary light reflex?

Answer 35

absent menace abnormal pupillary light reflex

Question 36

what can cause central vestibular disease?

Answer 36

infectious disease, basilar skull fracture, lightning strike, infiltrative disease degenerative/metabolic/toxic/vascular

Question 37

what can cause peripheral vestibular disease?

Answer 37

otitis media/interna THO guttural pouch infection stylohyoid fracture lightning strike

Question 38

what type of nystagmus is associated with central vestibular disease?

Answer 38

horizontal, rotary, vertical positional changes

Question 39

what is the pathway of the slap test?

Answer 39

thoracic spinal nerves dorsal grey column vagus nerve

Question 40

what does the patella reflex test?

Answer 40

integrity of femoral nerve and L4-L6 spinal cord segments

Question 41

what can ataxia stem from?

Answer 41

vestibular general proprioceptive cerebellar

Question 42

what does the general proprioceptive system transmit limb and trunk position information to?

Answer 42

cerebellum some to cerebrum for conscious proprioception

Question 43

does cerebellar disease cause paresis?

Answer 43

no

Question 44

how does dysfunction of the abducent nerve (cranial nerve VI) manifest?

Answer 44

medial strabismus inability to retract globe

Question 45

how does dysfunction of the trochlear nerve (cranial nerve IV) manifest?

Answer 45

dorso-lateral strabismus

Question 46

what might a lesion in the pons manifest as? which cranial nerve?

Answer 46

atrophy of masticatory muscles cranial nerve V

Question 47

which cranial nerves are associated with the rostral medulla?

Answer 47

cranial nerves V, VI, VII, VIII

Question 48

which cranial nerve is associated with the pupillary light reflex?

Answer 48

cranial nerve III

Question 49

when can a menace be absent but a pupillary light reflex be normal?

Answer 49

lead polioeencephalomalacia

Question 50

why is a menace absent in botulism?

Answer 50

cranial nerve VII

Question 51

is the fast phase of nystagmus usually away or towards the lesion in central vestibular disease?

Answer 51

away from lesion

Question 52

on which side are general proprioceptive deficits in central vestibular disease?

Answer 52

ipsilateral limb

Question 53

can physiological nystagmus be absent in peripheral vestibular disease?

Answer 53

yes

Question 54

what nerve does the motor response of withdrawal of the pelvic limb use?

Answer 54

sciatic nerve

Question 55

what nerves does the motor response of withdrawl of the thoracic limb use?

Answer 55

axillary nerve musculocutaneous nerve median and ulnar nerves

Question 56

where might lower motor neuron deficits be related to lesions?

Answer 56

spinal cord segment at the level of reflex arc peripheral nerves neuromuscular junction muscle

Question 57

what do upper motor neurons do?

Answer 57

initiate voluntary movement maintain tonus maintain posture control muscular activity associated with visceral functions

Question 58

when might hypermetria be seen?

Answer 58

floating gait: general proprioceptive ataxia worse with head elevation

Question 59

does a continuous pull or intermittent pull better assess ataxia (ataxia versus weakness- UMN vs GP)?

Answer 59

intermittent better for ataxia: GP

Question 60

does cerebellar disease cause paresis?

Answer 60

no

Question 61

what are the signs of a cerebrum lesion?

Answer 61

alerted mentation seizures blindness