1. The Cranial Nerve Exam
By Kayatre Giritharadas

2. Learning Outcomes
To be able to:
1. Examine of visual fields by confrontation
2. Examine of eye movements
3. Examine of the muscles of the face – Motor trigeminal and
facial nerve examination

3. Cranial Nerves

4. Year 1
We will cover the examination of the following
cranial nerves
• CN II optic
• CN III oculomotor
• CN IV trochlear
• CN VI abducens
• CN V trigeminal
• CN VII facial

5. Through the
following
examinations
• Visual fields (CN II)
• Eye movement (CN III, IV and VI)
• Facial movement (CN V and VII)

6. Sensory cranial nerves help a
person see, smell, and hear.
Motor cranial nerves help
control muscle movements in
the head and neck.

7. Optic Nerve CNII
• CN II sensory information from retina
to the brain
• Involved in:
• Pupils size, acuity and reflexes
• Visual acuity
• Colour vision
• Visual fields

8. Oculomotor (CN
III), trochlear (CN
IV) and
abducens (CN VI)
nerves
• Transmits motor information to
extraocular muscles
• Controls eye movements and eyelid
function
• The oculomotor nerve also carries
parasympathetic fibres responsible for
pupillary constriction.

9. Muscles of the Eye

10. Innervation of the Eye Muscles
• CN III Oculomotor:
• Medial rectus
• Superior rectus
• Inferior rectus
• Inferior oblique
• CN IV Trochlear
• Superior oblique
• CN VI Abducens
• Left Rectus
SO4 LR6
• Superior oblique – 4
• Left rectus - 6

12. Trigeminal CN V
Trigeminal Nerve CN V
• Sensory information about facial
sensation
• Motor information to the muscles of
mastication.

13. Facial CN VII
Facial Nerve CN VII:
• Sensory component taste anterior 2/3
of tongue
• Motor information about facial
expression

14. Important Points – Visual Fields
• Always cover your opposite eye to theirs
e.g. patient covers left eye, doctors covers
right eye
• Your eyes should be at the same height as
theirs
• Your hand should be in the middle between
you and the patient
• Patients wearing glasses must be able to
see well enough without glasses to do the
examination without them – otherwise
advise them to wear them

15. Important Pointers – Eye Movements
• Finger must be equidistant between you and the patient
• Only patient’s eyes should move not their face
• As for pain or double vision
• Observe for nystagmus (abnormal involuntary horizontal movement
of the eyes) in adduction and abduction

16. Important Points
Muscles of massification
Jaw power
Facial Expression:
1.“Raise your eyebrows”
2.“Close your eyes tightly” with resistance
3.“Show me your teeth” with resistance
4. “Blow out your cheeks”

17. When things
go wrong –
Optic Nerve
CN I

19. When things go wrong CNIII, CNIV, CN VI

20. Thank you
Please complete this short survey
about the session – will take only 2
minutes