Cranial nerve exam Flashcards
Cranial nerve 1- olfactory
have you noticed any change in your sense of smell?
have you had a cold or a head injury?
nerve 2- optic
do you ever get double vision?
Do you have difficulty seeing the stairs when you walk downstairs?
Do you wear glasses?
resting position of eyes, eyelid and pupil abnormality,
nystagmus
take your time
Snellen chart with one eye occluded (6m)
visual fields by confrontation
fundoscopy
light reflexes
accommodation reflex
Eye movements (2, 3, 4, 6) -optic, oculomotor, trochlear, abducens
H test
slowly
nerve 5 (trigeminal)
light touch comparing side to side
offer pin prick
muscles of mastication:
clench teeth and palpate for masseter and temporalis
protraction and side to side movement
open jaw against resistance
jaw jerk
nerve 7 (facial)
inspect for asymetry
test muscle power: grimace and show me your teeth say me-me-me puff out your cheeks screw your eyes up look upwards
corneal reflex
bells palsy
lower motor neurone lesion- forehead and face paralysed
stroke
UMN lesion, forehead spared while face is paralysed
taste and salivation (facial nerve)
have you had a change in taste
have you had a dry mouth or dry eyes
Ears
ask about hearing problems
inspect ears- look for hearing aid, pinnae, scalp, ear canals
perform auroscopy
Cn 8 - vestibulocochlear
whisper test
weber’s test
rinne’s test
audiometry
ask about vertigo
glossopharyngeal (9) and vagus (10)
inspect palate and pharynx with a pen torch say ahh ask patient to cough say kuh kuh kuh gag reflex swallow water
accessory nerve- 11
head movement- side to side and forwards
shrug shoulders against resistance
hypoglossal- 12
inspect the tongue
stick out tongue
movements of tongue (side to side)
power of tongue (push into cheek)
speech- say a tongue twister (yellow lorry, baby hippopotamus)
Uvula moves to one side
suggests a lesion of vagus.
uvula does not move
bilateral palatal muscle paresis
gag reflex
must be done before asking patient to swallow water
weber and rinne’s
offer if whisper test is reduced
corneal reflex branches
5- afferent
7 efferent
pathological jaw jerk
brisk reflex- bilateral UML
light touch
demonstrate on sternum first
ocular paresis of cn 3
ptosis, eye is lateral and slightly downwards, pupil may be dilated and unresponsivec
ocular paresis of cn 4
impaired depression of fully adducted eye, head may be tilted to the opposite side
ocular paresis of cn 6
impaired abduction
what nerves are tested in the corneal reflex
5 and 7
what could cause an oculomotor nerve lesion
raised intracranial pressure and downward depression of the brain compressing the third nerve against the free edge of the tentorium cerebelli.
what does a 3rd cn lesion present as
Ptosis, eye deviated laterally and slightly downwards, pupil may be dilated and unresponsive.
what does a 4th cn lesion present as
impaired depression of the fully adducted eye, head tilted to the other side
double vision
what does a 6th cn lesion present as
impaired abduction
what are the causes of nystagmus
abnormalities of the vestibular system
abnormalities of the cerebellum or central vestibular connections
damage to the retina
what part of the brain controls persuit eye movements
occipital lobe
what eye muscles are controlled by occulomotor
levator palpebrae
medial rectus
superior rectus and inferior oblique
inferior rectus
what nerve supplies superior oblique
trochlea
what controls accommodation reflex
cn2 and cn3
