Cranial nerves Flashcards
Cranial nerve 1
olfactory - smell
Cranial nerve 2
optic - visual acuity, pupil response
Cranial nerve 3
Oculomotor - eye movement
Cranial nerve 4
Trochlear - eye movement
Cranial nerve 5
trigeminal - facial sensation and movement
cranial nerve 6
abducens - eye movement
cranial nerve 7
facial - facial expression
cranial nerve 8
Vestibulocochlear - hearing and balance
cranial nerve 9
Glossopharyngeal - swallowing and speech
cranial nerve 10
vagus - swallowing and speech
cranial nerve 11
accessory - sternocleidomastoid and trapezius
cranial nerve 12
Hypoglossal - tongue movement
what 2 cranial nerves concern swallowing and speech?
9 and 10
- glossopharyngeal and vagus
which 3 cranial nerves are involved in eye movement
oculomotor, trochlear, abducens
3,4,6
speech abnormalities suggest pathologies involving which cranial nerves
glossopharyngeal and vagu
eyelid or pupil abnormalities suggests a pathology involving which cranial nerve
oculomotor (3)
how to first inspect before cranial nerve exam?
speech abnormalities
facial dropp/ asym
muscle bulk
eyelid/pupil abnorm
facies
scars
hearing aids
limbs
how would you test the olfactory nerve (1)
px smell orange stick (or lemon peppermint coffee) eyes shut and tell you
give some causes for changes to sense of smell
mucus blockage
head trauma
genetics
parkinsons
covid 19
when testing the optic nerve (2) what inspection would you do
check pupils same sizew and shape
how can visual acuity be checked when doing an assessment on cranial nerve 2/ the optic nerve
snellen chart
test one eye at a time to see changes. reaching line 6 at 6m = 6/6 = 20/20 vision
what score on a snellen chart would prompt you to need to wear glasses when driving
6/12
how can visual fields be checked when assessing the optic nerve
confrontation
causes of visual field changes
stroke
tumour
abscess
ms
ocular disease
how can homonymous defects be detected when assessing the optic nerve
finger waggling
what 2 pupillary reflexes are checked in an assessment of the optic nerve
direct and consensual
and accomodation
what equipment is used to carry out fundoscopy
ophthalmoscope
causes for abnormalities in pupillary responses
retinal damage
central vein occlusion
optic neuropathy
glaucoma
compression due to tumour or abscess
causes of changes in acuity
refractive errors
retinal diseases
cataracts
neuritis
lesions in visual pathway
optic nerve exam (2)
pupils reflex - direct and consensual/accommodation, visual fields, visual acuity, homonymous defects, fundoscopy
how do you test cranial nerves 3, 4 and 6 (oculomotor, trochlear and abducens)
ask if diplopia (double vision),
track H finger,
repeat with each eye shut.
what are you looking for when drawing a h, what may irregular eye movement suggest?
nystagmus which may suggest a stroke or vestibular nerve pathology
to check the trigeminal nerve (5) facial sensation in all 3 branches is touched lightly to indentify pain, what are the 3 areas that must be checked
ophthalmic
maxillary
mandibular
forehead, cheek, jaw
cranial nerve 5 exam
facial sensations forehead, cheek and jaw.
open jaw against resistance and side to side against resistance, inspect bulk.
how are the muscles of mastication checked when assessing trigeminal nerve function
inspect jaw
open jaw against resistance
jaw side to side
what muscles are being tested when looking at the muscles of mastication
masseter
temporalis
pterygoid
before investigating the facial nerve (7) what should the face be examined for
asymmetry
to test the facial nerve patients are asked to make a series of movements, what are these
raise eyebrows
show teeth
purse lips
blow out cheeks
screw eyes shut- try to open
what is the most common cause of LOWER motor neuron lesions
bell’s palsy
facial nerve palsy caused by LOWER motor neurone lesion presents with?
weakness of ipsilateral muscles of facial expression due to loss of innervation to all muscles on the affected side
facial nerve palsy caused by UPPER motor neurone lesion presents with?
unilateral facial muscle weakness. upper facial muscles partially spared
most common cause of UPPER motor neuron lesion
stroke
what 4 tests can be used to check the vestibulocochlear nerve (nerve 8)
whispering
weber
rinnes
turning
how does the whispering test work
stand behind patient and ask patient to repeat words
mask other ear with rubbing tragus
start at normal volume and reduce to whisper then at 60cm
if you detect hearing loss with the weber and rinnes test you should determine if it is sensorineural or
conductive
how is the turning test done and what are the results
ask patient to march on spot
arms outstretched
eyes closed
normal patient stays in same position
vestibular lesion patient will turn towards side with lesion
whats the webers test?
tuning fork thing on forehead and should hear on both sides
…
determine whether there is a unilateral problem but cant localise
normal Rinne’s test result
air conduction better than bone conduction
how to do Rinnes tets?
tuning fork thing on bone behind ear then air by ear…
conductive deafness: bone conduction > air
normal: air> bone
cranial nerve 9 and 10 exam (glossopharyngeal and vagus)
ask px had difficulty swallowing/ changes to voice or cough
assess speech for dysarthria/ dysphonia
look at palate and uvula and say ah
ask pt to cough
swallow test
gag reflex
how are the accessory nerves (11) checked
- turn cheek in hand - sternocleidomastoid muscle
palsy = weakness in this - shrug shoulders to assess trapezius muscle
cranial nerve 12 exam (hypoglossal)
stick out tongue
look for deviation
move from side to side
through check to assess power
bells palsy vs stroke in terms of muscle innervation
when cortex injured muscle weakness in contralateral lower face only
when facial nerve injured weakness in ipsilateral upper and lower face
bells palsy- eye may remain slightly open when try to close
the innervation of the muscles of the upper face originates on both sides of the brain whereas the innervation of the lower face comes from the x side of the brain only
opposite
what is the coordination of swallowing controlled by?
trigeminal, facial, glossopharyngeal, vagus and hypoglossal
