Module 2_Examination 2 (Cranial Nerves)

Question 1

When should olfaction be evaluated and how?

Answer 1

• When patient complains of loss of taste
• Ask them if they can smell the roses and cooking oils, if they say can’t test it
• If no sense of smell CT scan of cribriform plate area also required

Question 2

When are ophthalmological tests mandatory?

Answer 2

-Recent traumatic injury to the face

Question 3

How can binocular vision and eyelid function be tested?

Answer 3

Binocular visit

• Get pt to keep head still and visually track an object
• In normal pt should be able to move eyes together
• Must be tested in pt with recent facial injury

Eyelid function
-Get patient to open and close eyes

Question 4

Which regions are covered by the ophthalmic nerve?

Answer 4

• Forehead to crown of head (supraorbital + supratrochlear branches)
• Sensory nerve of eyeball (via nasociliary nerve which divides into short and long ciliary nerves)
• Down the to nose tip (via infratrochlear and anterior ethmoidal branches)

Question 5

What region does the maxillary nerve cover?

Answer 5

• Side of nose, cheeks (infraorbital)

- Nerve to sinuses, upper gums and teeth (anterior, middle, posterior alveolar nerves)

Question 6

What are does the mandibular nerve cover?

Answer 6

• Lower lips, teeth, tongue and face (inferior alveolar, mental, incisive, lingual)
• Extends to the ear (auriculotemporal)

Question 7

What anatomical variations can exist with the mandibular nerve?

Answer 7

• Buccal nerve supplies sensory info to outside skin of cheek (10% of people)
• Mylohyoid nerve cutaneous supply to the chin, but does not supply lip (5% of people)–> mandibular 3rd molar trauma may cause numbness of the chin
• Great auricular nerve may supply part of mandibular posterior gingiva and skin up to TMJ

Question 8

How is sensory nerve testing done?

Answer 8

• Take history
• Objective testing
• Sensory nerve function

Question 9

What type of tests are available to test sensory nerves?

Answer 9

Sharp vs blunt

• Use sheathed injection needle
• Unsheath the end that goes into the syringe
• Touch patient with both the capped and uncapped end and see if they can tell sharp or blunt with eyes closed

Two point

• Use a pair of tweezers
• Test whether patient can tell whether you’re touching with one point (tweezers ends together) or two points (tweezer ends apart)
• If believe patient faking then test across the upper lip (maxillary division) and lower lip (mandibular division)–>should feel as two as two separate branches even if one nerve damaged?

Directional sense
-Move a blunt instrument across face (e.g. capped needle) and get them to tell you in which direction is it moving in?

Question 10

Is testing of motor nerve function of trigeminal indicated?

Answer 10

No, as palsy of muscles of mastication supplied by motor branch (anterior division of mandibular nerve) is not compatible with life

Question 11

What tests can be used to check motor function of facial nerve?

Answer 11

• Lift eyebrows
• Close eyes
• Grimace and smile
• Purse your lips

Question 12

Where does the chorda tympani join the lingual nerve?

Answer 12

Near lower border of lateral pterygoid muscle

Question 13

How can taste be tested?

Answer 13

• Placing sweet or salty food on the side of tongue or floor of mouth (as these buds are not as specifically located as generally believed)
• Don’t forget to check smell if complaining about loss of taste

Question 14

When should hearing be tested and how?

Answer 14

• Trauma patients
• Patients who have had TMJ procedure (such as arthrocentosis or arthrotomy)
• Ask to look at ear if patient says they’ve already been to medical practitioner with ear ache

Whisper near their ear

Question 15

T or F

-Ear pain is related to the vestibuloucohclear (8th) nerve

Answer 15

F

Question 16

What are the main common causes of ear pain?

Answer 16

-Referred pain from jaw, neck or both, but there is a proportion which is caused by ears (rarer)

Question 17

Which nerves are involved in ear pain?

Answer 17

-V, IX, X, C2 (great auricular)

Question 18

How can the external ear canal be examined?

Answer 18

Auricsope or orthoscope (but we’re unlikely to do this)
(Pull external ear to straighten canal before insertion)
Check for perforations of tympanic membrane, signs of inflammation, bulging

Question 19

Which region is supplied by the glossopharyngeal nerve?

Answer 19

-Anterior pillar of the fauces, soft palate, tonsils, also supplies exteranall auditory meatus

Question 20

How do you test glossopharyngeal nerve function?

Answer 20

-Tetsting pretty much the same for trigeminal nerve, though pt may gag

Question 21

What is glossopharyngeal neuralgia?

Answer 21

-Sharp, jabbing pain in the throat on swallowing

Question 22

What does the coverage area for the vagus nerve?

Answer 22

• Has sensory part that coveres posterior part of tongue
• Sympathetic fibre to the eyes
• Sympath to sinuses
• Regulation of heart

Question 23

What does the accessory nerve cover?

Answer 23

• Major nerve to head and shoulder
• Also supplies some of the striated muscle in the pharynx
• If palsied, patient can’t lift their shoulder or can only do so weakly–> sign of tumour pathology within the neck or consequence of neck dissection

Question 24

What are signs of the paralysis of hypoglossal nerve?

Answer 24

• One side of the tongue won’t protrude
• Tongue points to affected side
• Over time tongue on affected side can become atrophic

Question 25

What can cause hypoglossal palsy?

Answer 25

• Trauma to nerve

- Nerve tumour