Cranial nerves examination Flashcards
set up for cranial nerve examination
sitting in chair 1m away from you
cranial nerve 1 testing
ask if any change in sense of taste/smell
what is anosmia an early sign of?
parkinsons disease
memory aid for 4 aspects of CN2 exam
AFRO
Acuity
Fields
Reflexes
Opthalmoscopy
How to test visual acuity
formally: snellen chart from distance of 6m with eye covered up in turn
informal: ask patient to read word on name badge
how to test visual fields neglect?
facing patient, ask them to look at your nose and keep head still
hold fingers approx 60cm apart and ask patient to point to the finger that moves
what will happen if a person has visual fields neglect?
wiggle both fingers at the same time, a patient with neglect will only note one finger moving
how to test peripheral visual fields informally
keep head still, eyes closed, wiggle finger from outside visual field towards centre, test all four quadrants
how to formally assess peripheral visual fields
goldmann kinetic perimetry and Humphrey visual fields testing
how to test visual reflexes?
make sure any ambient light is dim
check pupil size, shape, symmetry
direct reflex
consensual reflex
swinging light test
first step in testing CN3,4, 6
ask patient to fixate on tip of pen held 50cm in front of their nose
-> inspect for ptosis, nystagmus, strabismus
testing for diplopia CN 3,4,6
ask about diplopia in first position
H shape movement
ask them to tell you if they have any pain or double vision
what do you do after doing the H test in CN3,4,6
smooth pursuit -> move your finger relatively rapidly from left to right and back again, pausing at the edges of the gaze
look for nystagmus
CN5 testing
Sensation: ophthalmic, maxillary, mandibular with cotton wool
Motor: masseter and temporalis (chomp down)
what are the CN5 reflexes?
corneal (afferent V1, efferent VII)
jaw-jerk (afferent V3, efferent: motor V)
movements to ask for in CN7 testing
raise eyebrows
scrunch up eyes
puff out cheeks
show teeth
CN8 testing
whisper a number in the patient’s ear in turn, ask them to repeat it
if hearing loss, offer:
- Rinne test
- Webers test
- Otoscopy
- Audiometry for formal assessment
CN 9,10 testing
uvula deviation after getting them to say ‘arghhh’
CN11 testing
Spinal accessory
-> ask to shrug shoulders and keep them there against resistance (trapezius)
-> ask patient to turn head and push back against examiners hand (sternocleidomastoid)
CN12 testing
Inspect tongue at rest
-> wasting and fasciculations in MND
-> tongue deviation towards side of lesion in LMN pathology
Test power of tongue against each cheek
clinical signs of complete unilateral CN3 palsy
ptosis
down and out eye
diplopia worst when looking up and out
fixed dilated pupil
causes of a unilateral ptosis
Third nerve palsy
Horners syndrome
Myasthenia gravis
causes of a bilateral ptosis
myasthenia gravis
neurosyphilis
difference between a medical and surgical third nerve palsy
medical = pupil sparing and painless
surgical = pupil fixed and dilated
