Neuro exam and intro to diagnostic testing

Question 1

What is the first thing to assess when doing neuro exam in horse

Answer 1

Changes in mentation:
- Abnormalities of cerebral function
- Abnormal states of wakefulness

Question 2

How do we assess olfactory nerve (CN1) in horses

Answer 2

Nothing we can really do

Question 3

How can we assess the optic nerve (CN2)- horse

Answer 3

Menace response
Pupillary light reflex

Question 4

Describe the menace response

Answer 4

blink= facial nerve
withdrawal response- tests central processing
learned response- absent for first 2 weeks of life

Question 5

what is anisocoria

Answer 5

is the unequal or asymmetrical pupils

Question 6

what are CN 3,4 and 6 responsible for

Answer 6

movement of eye

Question 7

what is ptosis

Answer 7

is known as the drooping of the upper eyelid
neuro or ocular pain

Question 8

How do we test CN5 (trigeminal) in horses

Answer 8

test skin sensation - over whole of face

Question 9

Describe how to test CN 7 (facial) in horses

Answer 9

is nerve of facial expression
look at facial symmetry

Question 10

In cases of facial nerve dysfunction which was does muzzle deviate

Answer 10

normal tone causes deviation of nose away from side of paralysis- towards good side

Question 11

How to test CN 8 (vestibulocochlear) in horse

Answer 11

Noise response
is head tilt present- vestibular problem
presence of nystagmus- eye can’t fixate on environment

Question 12

How do we test CN 9 (glossopharyngeal) in horse

Answer 12

check horse tongue tone- can it retract its tongue

Question 13

How can we test CN 11 (accessory spinal) in horses

Answer 13

Important innervation of nerves of neck- can it move its neck

Question 14

How do we test CN 12 - hypoglossal

Answer 14

Can they chew food normally
check tongue tone and retraction

Question 15

Describe spinal reflexes in horses

Answer 15

cutaneous trunci response- skin twitching in response to stimuli
Anal sphincter tone
Tail tone

Question 16

Describe gait assessment as part of horse neuro exam

Answer 16

Assess at walk
Circling
Ataxia
Blindfold

Question 17

what does circling in horse assess

Answer 17

can the horse move their legs appropriately
always check both ways

Question 18

How can blindfolding horse help in neuro exam

Answer 18

Not done on every case- but can exacerbate to make it easier to see in mild cases of ataxia

Takes away visual feedback

Question 19

How can blood work help to investigate neuro disease in horses

Answer 19

Differentiate infectious or inflammatory conditions
Increased WBC count, increased serum amyloid A, increased fibrinogen

Question 20

what is xanthochromia

Answer 20

CSF with yellow tinge to it
caused by breakdown products of red cells

Question 21

what cranial nerves can endoscopy be useful to look at in horses

Answer 21

CN that pass through guttural pouch
9, 10, 11, 12

Question 22

List 5 neuro abnormalities in horse that indicate needing to look in guttural pouch

Answer 22

Ptosis
muzzle deviation
head tilt
head shaking
ataxia

Question 23

when is radiography of the neck indicated in horses with neuro problems

Answer 23

Indicated in all cases of bilateral and quadrilateral ataxia

Question 24

what is gold standard diagnosis of neur exam of the horse
what are the risks of this

Answer 24

CT
but GA risk and contrast risk