Cranial Nerve Examination

Question 1

What is it useful to do when examining an older child?

Answer 1

Consider each area of the nervous system individually - the cranial nerves, cerebellum, upper limb, lower limb, and gait

Question 2

What is cranial nerve I (1)?

Answer 2

Olfactory

Question 3

What is cranial nerve II (2)?

Answer 3

Optic

Question 4

What is cranial nerve III (3)?

Answer 4

Oculomotor

Question 5

What is cranial nerve IV (4)?

Answer 5

Trochlear

Question 6

What is cranial nerve V (5)?

Answer 6

Trigeminal

Question 7

What is cranial nerve VI (6)?

Answer 7

Abducens

Question 8

What is cranial nerve VII (7)?

Answer 8

Facial

Question 9

What is cranial nerve VIII (8)?

Answer 9

Vestibulocochlear

Question 10

What is cranial nerve IX (9)?

Answer 10

Glossopharyngeal

Question 11

What is cranial nerve X (10)?

Answer 11

Vagus

Question 12

What is cranial nerve XI (11)?

Answer 12

Accessory

Question 13

What is cranial nerve XII (12)?

Answer 13

Hypoglossal

Question 14

What does CN 3 innervate?

Answer 14

• Ciliary muscles
• Sphincter of pupils
• All external muscles of eye except superior oblique and lateral rectus

Question 15

What does CN 4 innervate?

Answer 15

Superior oblique muscle

Question 16

What does CN 5 innervate?

Answer 16

Sensory to face, sinuses, and teeth

Question 17

What does CN 6 innervate?

Answer 17

Lateral rectus muscle

Question 18

What does CN 7 innervate?

Answer 18

Muscles of face

Question 19

What does CN 7 innervate via the intermediate nerve?

Answer 19

• Motor to submandibular, sublingual, and lacrimal glands
• Taste to anterior 2/3 of tongue
• Sensory to soft palate

Question 20

What does CN 8 divide into?

Answer 20

• Cochlear nerve

- Vestibular nerve

Question 21

What does CN 9 innervate?

Answer 21

• Taste to posterior 1/3 of tongue
• Sensory to tonsils, pharynx, and middle ear
• Motor to stylopharyngess, upper pharyngeal muscle, and parotid gland

Question 22

What does the CN 10 innervate?

Answer 22

• Motor to heart, lungs, palate, pharynx, larynx, trachea, bronchi, and GI tract
• Sensory to heart, lungs, trachea, bronchi, larynx, pharynx, GI tract, external ear

Question 23

What does CN 11 innervate?

Answer 23

• Sternocleidomastoid

- Trapezius

Question 24

What does CN 12 innervate?

Answer 24

Tongue

Question 25

How is CN 1 tested?

Answer 25

Asking patient if they have noticed any change in their sense of smell If test done, each nostril in turn

Question 26

How is CN 2 tested?

Answer 26

- Visual acuity - Visual fields - Pupillary reflexes - Fundoscopy

Question 27

What pupillary reflexes should be tested?

Answer 27

Direct and consensual responses to lift, then accommodation

Question 28

How should CN 3, 4, and 6 be tested?

Answer 28

Ask child to fix and follow on an object (light from pen torch is best in children)

Question 29

How should the motor component of CN 5 be tested?

Answer 29

- Ask child to open their mouth whilst you try and close it | - Clench teeth together and feel muscle mass of masseters

Question 30

What will be found when you ask the child to open their mouth whilst you try to close in if there is a CN 5 lesion?

Answer 30

It will deviate to the side of weakness

Question 31

What divisions provide the sensory functions of CN 5?

Answer 31

- Opthalmic - Maxillary - Mandibular

Question 32

How should you assess the sensory functions of CN 5?

Answer 32

Test each division and compare both sides

Question 33

Should you test the corneal reflex?

Answer 33

No

Question 34

How should you assess the motor component of the CN 7?

Answer 34

Ask child to close their eyes tightly, open their eyes really wide, blow out their cheeks, and show their teeth

Question 35

How should you assess CN 8?

Answer 35

Rinne's and Weber's test

Question 36

How should you assess CN 9 and 10?

Answer 36

Ask child to open their mouth and say 'ahh' whilst looking at palatal movement

Question 37

How should you assess CN 11?

Answer 37

Ask the child to shrug their shoulders, turn their head to the right, and place a hand on the left side of their face and ask to push against your hand

Question 38

How should you assess CN 12?

Answer 38

Ask the child to stick out their tongue and inspect for fasciculation and deviation

Question 39

What will be found on examination if there is a lesion of CN 12?

Answer 39

The tongue deviates to the side of the lesion