Cranial Nerves Examination

Question 1

When examining facial nerve VII, what do you look at

Answer 1

1. Facial symmetry
   - droopy eyelid, ear, lips
   - nostril size
2. Menace reflex (with Nerve II)
   - gently move hand towards eye
3. Palpebral reflex (with n. V)
   - Tap medial and lateral corners
4. Corneal reflex (with Nn. V & VI)
   - touch cornea with clean moist.
   cotton bud - usually with euthanasia
   cases

Question 2

When examining Vestibular nerve VIII, what do you look at

Answer 2

1. Head tilt
   - Rotation of head on its axis
2. Check strabismus (with Nn. III, IV & VI)
   - observe eye position in normal
   horizontal position or the head,
   then move head upwards - check if
   both eyes are still in same position
3. Positional nystagmus (with Nn. III, IV, VI)
   - move head upwards, normally eye
   should follow the head- once head
   has stopped, eye should stop too

Question 3

When examining Olfactory nerve I, what do you look at

Answer 3

1. Test ability of animal to smell,
   using food
   - eyes should be covered
   - do not use irritants, as these will
   stimulate sensory receptors of
   trigeminal nerve

Question 4

When examining Optic nerve II, what do you look for

Answer 4

1. Dropping cotton balls
   - normal reaction: head and eternal
   will follow the cotton ball
2. Menace (with N. VII
   - gently move hand towards the eye
3. Pupillary light reflex
   - shine pen light in one eye, repeat on
   other side - pupil should contract
4. Consensual Pupillary light reflex
   (with N. III)
   - While performing direct PLR, look
   at the contra-lateral eye. Other eye
   should also contract

Question 5

When examining Oculomotor nerve III, what do you look for

Answer 5

1. Pupil size
   - in dark room at arm’s distance with
   pen light behind your eyes, shine
   in both the animal’s eyes and look
   at the pupil’s retro-illuminated by
   reflection of tapetum
2. Pupillary light reflex (with N. II)
   - shine pen in one eye
3. Consensual PLR (with N. II)
   - look at contra-lateral eye with PLR
4. Check strabismus (with nn. IV, VI, VII)
   - observe eye position in normal horizontal position of head, then move head upwards and check if both eyes are in same position
5. Positional nystagmus (with nn. IV, VI, VIII)
   - move head upwards, eye should
   follow the hear and movement
   should stop once head stops
6. Oculovestibular response (with nn. IV, VI, VIII)
   - move head side to side to observe
   eye’s movements. Eyes should follow
   with jerky movements like nystagmus