Cranial Nerves Year 2 Flashcards
Cranial nerve and there part of the examination
Olfactory
- have you noticed a change in your sense of smelll
Optic
- get them to read something
- visual fields test - finger should be halfway between you and the patient
- pupillary light reflex, direct reflex, consueal reflex in each eye
Abducens, trochlear and oculomotor nerve
- movement of the eye H sign - ask them if they see double
trigeminal sensory aspect of the nerve
- sensation of the face - ask if they feel your touching it, if it is normal and the same both side
trigeminal nerve
- open your mouth and prevent me from closing it
facial nerve
- muscle of facial expression
- puff out your cheeks
- toothy grin
vestibulocochlear?
- whisper 2 digit number and mask it on the other side
vagus/glossopharyngeal?
- visualise the soft palate and get them to say ahh
Hypoglossal Nerve
- ask them to stick the tongue out
Spinal accessory Nerve
- shurg there shoulders
What are you looking for in inspection
- May reveal a facial palsy
Ptosis - Ophthalmoplegia (eye patch)
- Craniotomy scars (not usually obvious from an anterior inspection, can look behind the ear)
- PEG/trachy - due to not being able to swallow properly
what can an introduction reveal
May reveal a dysphasia or dysphonia
May reveal a decreased conscious level
Name the cranial nerves and there number
I = Olfactory II = Optic III = Oculomotor IV = Trochlear V = Trigeminal VI = Abducens VII = Facial VIII= Auditory (vestibulo cochlear) IX = Glossopharyngeal X = Vagus XI = Accessory XII= Hypoglossal
How do you test for olfactory
Have you noticed any change in your senses of taste or smell?
describe an example of acuity
– “6/36” means “I can see at 6m what an average person can see at 36m”
How do you test acuity
= ask them to read something
= ask them if they are wearing their glasses
= remember to examine each eye separately - cover one eye get them to read and cover the other eye and get them to read
- use a snellen chart in order to quantify it (won’t use one as you won’t have one and won’t have the distant marked on the floor)
How do you examine the visual fields
Fields – tested by confrontation
This allow you to compare the patients visual fields to your own (assumed normal)
In quadrants
One eye at a time
name some eye defects that can arise
1 Monocular blindness 2 Bitemporal hemianopia 3 Contralateral homonymous hemianopia 5 C. hom. inferior quadrantanopia 6 C. hom. superior quad
how do you examine the pupillary light reflex
using a pen torch
what are the 6 reflexes to test
- direct
- consensual
- accommodation - bringing one finger in towards the patients nose and as there eyes converge their pupils constrict
= these these in each eye
name some pupillary abnormalities
Small pupil (miosis) - opiate drugs can cause the pupils to constrict, tend to be smaller in older people as well can be due to: = Drugs eg Opiates = Pons = Horner’s syndrome = Old age
Dilated pupil (mydriasis) = sometimes done on purpose to get a better view can be due to: - Drugs eg Atropine - Oculomotor palsy - Ocular trauma (irregular)
what does a fundoscopy allow you to do
– you can actually see the end of the second cranial nerve
How do you check for colour vision
Colour vision – Ishihara chart
= can check for colour blindness
what causes horizontal movements in the eye
medial rectus = moves inwards (adduction)
lateral recuts = moves outwards (abduction)
what nerve supplies the lateral rectus
abducens nerve
describe what the eye muscles do
- superior oblique
- inferior oblique
- superior rectus
- inferior rectus
- Superior oblique = inycloduction
- inferior oblique = excyloduction
superior rectus
- elevation
- adduction
inferior rectus
- depression
adduction
How do you test superior and inferior rectus
but with the eye abducted, the superior and inferior recti move the eye up and down
How do you test superior and inferior oblique
with the eye adducted, the inferior and superior obliques move the eye up and down
what does oculomotor palsy result in
An oculomotor palsy results in a dilated pupil and a depressed, abducted eye (down and out)
How do you examine the trigeminal nerve
Examine facial sensation to fine touch in all 6 areas
Muscles of mastication “clench your teeth” “open your mouth”
Jaw jerk
How do you examine the facial nerve
“Raise your eyebrows”
“Screw your eyes tight shut”
“Puff out your cheeks”
“Big smile”
why does an UMN spares the forehead in the face
An UMN weakness of the face, spares the forehead. Because the forehead area of the facial nucleus is innervated by both motor cortices.
Why might facial weakness develop
bells palsy - knocks out the whole side the face
stroke - only bottom half of the face as UMN
describe how the corneal reflex works
Stroking the cornea with a wisp of cotton wool, causes the eye to blink
Vophth & VII
Part of brain stem tests= maybe if they are brain dead
Can cause corneal abrasion thus not routinely performed
How do you test the vestibule-cochlear nerve
A crude bedside test
Mask one ear with tragal massage
Whisper a number into the tested ear
Ask the patient to repeat the number
what tuning fork do you use for weber and rhinne
512Hz tuning fork
describe how weber and rhinne test works
The basis for the tests is sensory adaptation – when there is a conduction defect in an ear, the hair cells receive less stimulation and so become hypersensitive.
Acoustic conduction can be bypassed by placing a tuning fork on the skull – in which the cochlear is embedded
(don’t do in the exam)
describe how you form the weber and rhinne test
Weber - in which ear is the sound louder?
Rinne – which is louder? Air or bone?
In a R conductive deafness, Weber localises to R and bone stimulus is louder on Rinne
In a R sensorineural deafness, Weber localises to L and air stimulus is louder on Rinne
How do you test for cranial nerves IX, X and XI
Open mouth, say “ah”
The uvula will be seen to elevate. It will deviate away from the side of a bulbar palsy
Gag reflex – when the posterior pharyngeal wall is stimulated with a cotton bud, the patient gags. This is an unpleasant thing to do to someone.
how do you examine spinal accessory nerve
Shrug you shoulders”
Tests trapezius
How do you examine XII
Stick out your tongue”
Look for fasciculation and wasting
Deviates towards side of palsy (the muscles of the tongue are pushing it out
