Module 2_Examination 2 (Cranial Nerves) Flashcards
When should olfaction be evaluated and how?
- 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
When are ophthalmological tests mandatory?
-Recent traumatic injury to the face
How can binocular vision and eyelid function be tested?
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
Which regions are covered by the ophthalmic nerve?
- 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)
What region does the maxillary nerve cover?
- Side of nose, cheeks (infraorbital)
- Nerve to sinuses, upper gums and teeth (anterior, middle, posterior alveolar nerves)
What are does the mandibular nerve cover?
- Lower lips, teeth, tongue and face (inferior alveolar, mental, incisive, lingual)
- Extends to the ear (auriculotemporal)
What anatomical variations can exist with the mandibular nerve?
- 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
How is sensory nerve testing done?
- Take history
- Objective testing
- Sensory nerve function
What type of tests are available to test sensory nerves?
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?
Is testing of motor nerve function of trigeminal indicated?
No, as palsy of muscles of mastication supplied by motor branch (anterior division of mandibular nerve) is not compatible with life
What tests can be used to check motor function of facial nerve?
- Lift eyebrows
- Close eyes
- Grimace and smile
- Purse your lips
Where does the chorda tympani join the lingual nerve?
Near lower border of lateral pterygoid muscle
How can taste be tested?
- 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
When should hearing be tested and how?
- 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
T or F
-Ear pain is related to the vestibuloucohclear (8th) nerve
F
What are the main common causes of ear pain?
-Referred pain from jaw, neck or both, but there is a proportion which is caused by ears (rarer)
Which nerves are involved in ear pain?
-V, IX, X, C2 (great auricular)
How can the external ear canal be examined?
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
Which region is supplied by the glossopharyngeal nerve?
-Anterior pillar of the fauces, soft palate, tonsils, also supplies exteranall auditory meatus
How do you test glossopharyngeal nerve function?
-Tetsting pretty much the same for trigeminal nerve, though pt may gag
What is glossopharyngeal neuralgia?
-Sharp, jabbing pain in the throat on swallowing
What does the coverage area for the vagus nerve?
- Has sensory part that coveres posterior part of tongue
- Sympathetic fibre to the eyes
- Sympath to sinuses
- Regulation of heart
What does the accessory nerve cover?
- 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
What are signs of the paralysis of hypoglossal nerve?
- One side of the tongue won’t protrude
- Tongue points to affected side
- Over time tongue on affected side can become atrophic
What can cause hypoglossal palsy?
- Trauma to nerve
- Nerve tumour
