Cranial nerve examination Flashcards
What is the first part of any introduction to an examination?
Wash hands
Intro self
Pt details
Explain a CN exam to a patient
I’ve been asked to examine the nerves that supply your head and neck today, it’s going to involve me testing a range of sensations and movements in your face if that would be okay?
What else would you include in your intro?
Pain or discomfort?
What equipment is needed in a CN exam?
Pen torch.
Cotton wool.
Tuning fork (512Hz).
Water.
When inspecting generally what do you look for?
Scars.
Neurofibromas.
Facial asymmetry.
Hearing aid/glasses.
Ptosis, proptosis, skew deviation of eyes or unequal pupils.
When can dysarthria be assessed?
When confirming patient details.
How do you test CN I?
“Have you noticed any recent change in your sense of smell?”
If yes –
- Test each nostril separately by occluding the
contralateral + use soap/coffee.
How do you test CN II?
Visual fields by confrontation –
- Sit opposite the patient about 1m away.
- Patient covers one eye + you cover the opposite eye +
ask patient to stare into your other eye + move index
finger from a point outside of your visual field diagonally
toward the centre of visual field + ask patient to signal
when they first see the object.
- This should be at the same time that you do.
Visual inattention/extinction –
- Hold hands up in the periphery of the patient’s visual
field (one each side) + move tip of index finger up +
down one side at a time and then on both sides + ask
patient which side is moving.
Direct + consensual light reflexes –
- Ask patient to look straight ahead + shine light source in
from the side make sure the pupil constricts (direct light
reflex) + the contralateral pupil constricts (consensual
reflex).
Accommodation reflex –
- Ask patient to focus on a distant point + then to focus on
finger held approx. 30cm in front of their nose.
Normal = pupils both constrict.
How do you test CNIII, CIV and CNVI?
What should you observe for?
Ask the patient to keep their head still + follow finger with eyes.
Trace large H shape + a central I shape with finger taking the patient’s eyes to the limit of their gaze.
Ask the patient - “Did you experience any double vision?”
Observe for disconjugate eye movements + nystagmus
How do you test CNV?
Sensation –
- In skin supplied by the ophthalmic, maxillary +
mandibular nerves with cotton wool then pin prick,
comparing left to right.
- Demonstrate sensation on sternum first.
Motor –
- Palpate contraction of temporalis (temples) + masseter
(cheeks) muscles while the patient clenches their
mouth.
- Ask patient to open mouth against resistance.
True or false?
Jaw deviation occurs towards the side of the paralysed pterygoid.
TRUE
What over reflexes are included when testing CNV but are not in the OSCE?
Jaw jerk
Corneal
How do you test for CNVII?
Assess the motor supply to the muscles of facial expression –
- Raise your eyebrows.
- Close your eyes tightly + don’t let them be opened.
- Puff out your cheeks.
- Purse your lips.
- Show your teeth.
How do you test CNVIII?
Cover opposite ear with your hand + whisper a number to patient do this at 15cm then 60cm.
If abnormality suspected perform special tests.
Rinne’s test
- Vibrating tuning fork (512Hz) is held on mastoid then
moved to external acoustic meatus;
Weber’s test
- Vibrating tuning fork (512Hz) held against forehead in
midline.
- Increase sensitivity by having patient block their
external ear canals.
Vestibule ocular reflex –
- Sit facing patient + ask if any neck pain + ask if you can
turn head very quickly.
- Ask them to fixate on your nose + hold head covering
each ear + rotate very rapidly to left + then right.
Unterbeger / turning test –
- Ask patient to march on spot with arms outstretched +
eyes closed.
Dix-Hallpike test –
- Patient’s head turned to face you + in a quick, smooth
movement they are lied supine so that their head is
beyond the end of the couch with eyes open.
What is a normal Rinne’s test result?
What indicates conductive hearing loss?
What indicates sensorineural hearing loss?
Normal = louder at the external acoustic meatus.
Conductive hearing loss = louder on mastoid.
Sensorineural hearing loss = air + bone conduction are decreased by a similar amount.
