cranial nerve exam Flashcards
what is the general observation?
posture, gait, symmetry, hearing aids, abnormal movements, glasses
how would you test cranial nerve I?
olfactory - ask a simple question about their smell and any changes, if any doubt then get a strong smelling food and get them to identify with eyes closed
what are the four aspects of CNII that need testing?
visual field, visual acuity, pupillary reflex to light and accommodation and fundoscopy
how would you test CNII for pupillary reflex?
light - shine light into one and watch constriction, and other one and watch the other constrict consensually - both sides
accommodation - finger starts at 1m away and gradually moves closer - constrict as converge
visual acuity?
snellen chart
visual fields?
confrontation test - arms length away - move finger through four quadrants of vision
fundoscopy?
direct visualisation of the retina - obtain the red reflex, then follow all four vessels to the optic disc, visualise macula
why are III, IV and VI considered together?
they work synergistically together in eye movements - occulomotor, trochlear and abducens
how do you test III, IV and VI?
check for any asymmetry of eye position at rest and ptosis. then make H (vertical and horizontal) with finger in eye plane. Check they move synchronously and smoothly.
how would you test CNV sensory?
test light touch with cotton wool bud on three divisions and then sharp with neurotip
corneal - do not do unless lesion suspected - touch cornea with cotton wool - both eyes should blink - afferent is CNV and efferent is CNVII
how would you test trigeminal motor?
test muscles of mastication - masseter, pterygoids and temporalis
clench teeth whilst palpate temporalis and masseter
pterygoid - keep mouth open against resistance
move jaw from side to side
feel contraction of masseter and temporalis and not overcome pterygoid
jaw jerk
equal movements
what muscles are tested in testing of facial nerve?
in CNVII - frontalis, orbicularis oculi and oris, buccinators
how would you test CNVII?
muscles of facial expression - raise eyebrows, close eyes, show teeth and purse lips and blow out cheeks and keep all there - prior to this check symmetry and during each test
how do you test vestibulocochlear nerve?
CNVIII - clinical hearing test - ask if they have any issue - then whisper number in each ear - further tests done if needed
what are further tests for vestibulcochlear?
they check between sensorineural and conductive deafness
Rinne’s Test - vibrating tuning fork on A) entrance to external auditory canal and B) bony prominence of mastoid process - A louder than B is normal, B louder than A is conductive hearing issue
Weber’s - for unilateral hearing impairment - place tuning fork on one side of forehead and then other - check if same volume or if goes to one ear more - if there is then is a unilateral conductive or if positive Rinne’s then contralateral sensorineural hearing loss
