Cranial Nerves Flashcards
Optic nerve
To test if don’t see well, bump into things etc
- Visual Fields : Donder’s confrontation method
Something in the eye got in / don’t see anymore:
external inspection: first check whether the refractive media (cornea, anterior chamber, lens, vitreous humor) are intact and whether the patient’s vision is optimally corrected
Visual acuity (patient 5/6 meters away, tell nomenclature if number alphabet etc, look if dont squeeze eye, point, row without error is the visual acuity. Can also do through pinhole: light doesnt get in, test refractive)
Fundoscopy
Pupillary Responses
Donder’s confrontation method
Visual fields / Visual loss
Part of Optic nerve
Both sit
Face patient, be close but knees don’t touch
Be at same eye level
ask patient to close left eye and you close right eye
extend arms and have hands in the same plane as the knees: this way you have overlapping visual fields
Be sure to have hands on the borders of the visual field can move the hands toward the inside to pinpoint defects
Move fingers, alternate 1 hand, the other, both.
Patient indicate Right/left/both movements
Do with arms vertical, horizontal and diagonal
Do for each eye
if left lost : right optic tract damage
if right lost : left optic tract damage
if lateral lost: median lesion optic chiasm
if interior lost 1 eye: lateral lesion optic chiasm
if 1 lateral 1 interior lost: lesion optic pathway, if with a central point intact : visual cortex impaired
lost both upper or lower right quadrant: lession optic radiation
Pupillary response
Part of Optic nerve (affarent: receive stimulus) and Oculomotor nerve (efferent: carry stimulus)
Direct: the pupil of the eye which light is directed constrict
Indirect: the eye which light is not directed constrict. Put hand in between eyes to test.
If eye does not react: the optical nerve of that eye is damaged
Oculomotor Nerve
Can be tested for vision clarity, seeing double
Pupillary constriction
Lifting upper eyelid : check level and symmetry, is patient lifting eyebrow, tilting head. If doubt ask to close for a few seconds and open again
Eye movement
Test:
- Look at eyes symmettry and eye lids
- Shine a light to inspect if reflection symmetrical (center of pupil of both), if not then an eye is not centered
- Ask to follow finger up and if experience double vision at any point, down, left, right. Angle no more than 45 deg
- If double vision: hide 1 eye and ask which image image dissapear Right Right uncrossed Right Left crossed
- bring finger closer and closer to nose
- Ask to move eye the most to the left, right, up and down
Trochlear nerve and abducens nerve
Provide ocular movement with oculomotor nerve
Oculomotor does most.
Oblique inferior interior: trochlear
Lateral: abducens
Straight up down movement are composed movement and use multiple nerves
Facial Nerve
Facial expression and mouth function (Symmetry mouth)
Salivary glands, lacrimation
sense of taste
anterior 2/3 tongue
Test:
- Inspect face, assymetry at rest is physiological, look at symmetry during active movements too
- Raise eyebrow
- Firmly close eye, try to open patient eye with hand
- Blow cheeks
- Purse lips
- Show teeth
- Ask if any lost of taste: can test by putting something on tongue
- Hypersensitivity to noise ?
Peripheral facial paresis: one side loss muscle function
Central facial paresis: a lower half loss, upper half innervated by contralateral, -> Often sign of stroke or TIA (Transient ischaemic attack). FAST screening !! Face: eyes/mouth affected
FAST screening
In case of suspected stroke
Face: eyes/mouth affected. Ask to smile, is it dropping ?
Arms & legs: can move arms and leg well ?
Speech: can talk normally ? ask to repeat something or ask something simple
Time: How long has it been?
Send patient to hospital urgently if test positive
Vestibulochlear nerve
Auditory nerve & balance
Test:
tuning fork tests for hearing with Weber or Rinne or Schwabach test
Weber: strike tuning fork, place foot on middle forehead, ask if hear in middle, left or right. If unsure patient put finger in one ear. Then repeat with ears open. This test conductive deafness. If a side is said then there is lateralisation, conductive deafness of one side.
Rinne: strike fork, put on mastoid process of each ear the foot of the fork then turn fork towards ear. What ear the loudest ? air conduction should be better
Schwabach: strike fork, put foot fork on mastoid process and ask when patient no longer hears. then check yourself
assessment of balance Romberg’s, Barres test and heel-to-toe walking
nystagmus (uncontrolled movement eye): dim light, have patient look at finger at about 75cm, not more than 45deg (otherwise physiological), for about 20 sec up, down, right, left
positional vertigo: have patient sit on table, follow finger, then place hands over the head and tilt person over, turn head, ask to follow finger again, put person back up again and follow finger. Ask if dizzy. Do both side. Look if any nystagmus appear at any point
Trigeminal nerve
Corneal reflex (afferent path)
Facial sensory function & mastication muscle : masseter muscle
Test:
- Take a pick and use sharp and blunt side
- patient close eye
- Ask if blunt or sharp on multiple part of the face
- Ask if right or left is stronger
Test:
- Symmetry mouth (with facial nerve)
- Ask to open mouth and say “Ah’ inspect tongue, soft palate, uvula and pharynx (look if tongue is going straight)
-Palpate masseter muscle: clamp jaw tightly, feel next to jaw and on temporal side
- test masseter muscle: clamp on spatual, do both side of teeth
- maaseter reflex: open mouth slightly, have lower jaw reflex. Put thum on chin and strike finger. Look if jaw closes
Corneal Reflex
Efferent : oculomotor (turning eye ball away) and facial nerve (close eye)
Afferent : trigeminal (sensing the stimulus)
Test:
Cotton ball, twist in pick and put on cornea
Feel touch but blink differ left/right: facial nerve impairment
Does not feel cornea being touch: trigeminal nerve impairment
Olfactory nerve
Smell
test if patient complains about smell or taste
Anosmia : blindness of smell, often cause by rhinitis if not tumor,fracture, inflammation
Test:
Close eye
Shut one nostril with hand
Put an item with a smell: coffee, peppermint, etc
Ask what it is: can help with questions is this .. or .. ?
Test with ammonia: won’t smell with olfactory defect but will feel it because stimulate trigeminal nerve
if patient don’t notice anything: patient is faking
Glossopharyngeal
Stylopharyngeus muscle (lateral walls pharynx)
Sensation: Posterior 1/3 tongue ( & taste), pharynx, tonsils
Salivary glands
Usually tested with vagus
Test:
Open mouth widely: check uvula centered
Say “ah”: check uvula goes up, contraction upward of palate
Use a spatula to push tongue down and with blunt side of stick touch pharyngeal wall and have a gag reflex
If don’t feel touch: loss of glossopharyngeal
If assymetry: vagus
Vagus
voluntary Muscle palate, pharynx larynx
sensory: external ear, external auditory canal
muscle of heart, lungs, bronchi, oesophagus, abdomen (ilium, colon)
usually tested with vagus
Accessory nerve
Sternocleidomastoid and trapezius muscle
Test:
Stand behind patient
Pull shoulder up, push with hands as counter pressure
Ask to turn head to Left/right and apply conterpressure
Hypoglassus
tongue
Test:
Open mouth: position, shape, lie still
Stick tongue out: is it centered or towards left/right
Push tongue against cheek, with hand apply conter pressure
Tongue will lie on the healthy side, be atrophic on the concerned side
