OSCE Prep Flashcards
What is cranial nerve 2, what does it do, and how do you test it?
Optic nerve
Vision
Test visual acuity and test visual fields by confrontation
Test visual acuity by snellen eye chart or near vision test
Confrontation normal ranges are 50 degrees up, 90 degrees temporally, 70 degrees down, and 60 degrees nasal
What is cranial nerve 1, what does it do, and how do you test it?
Olfactory nerve
Smell
assess patency of nostrils; occlude one nostril at a time and ask patient to sniff
with eyes closed, occlude one nostril and present an aromatic substance - odor should be normally identified through each nostril
what is cranial nerve 3 and what does it do?
Oculomotor
Extra ocular muscle movement, opening of eyelids
pupil constriction and lens shape
what is cranial nerve 4 and what does it do?
Trochlear
Down and inward movement of eye
what is cranial nerve 5, what does it do, and how do you test it?
Trigeminal
Muscles of mastication
Sensation of face and scalp, cornea, mucous membranes of mouth and nose
assess muscles of mastication by palpating the temporal and masseter muscles as the patient clenches their teeth - muscles should feel equally strong on both sides; next try to separate the jaw by pushing down on the chin - normally you cannot
test sensory function by touching patients cheeks, chin and forehead with a cotton wisp, while their eyes are closed, asking them to say “now” whenever the sensation is felt - this tests all 3 divisions of the nerve (ophthalmic, maxillary, and mandibular)
what is cranial nerve 6 and what does it do?
Abducens
Lateral movement of eye
what is cranial nerve 7, what does it do, and how do you test it?
Facial
Facial muscles, close eye, labial speech, close mouth
Taste (sweet, salty, sour, bitter) on anterior two thirds of the tongue
Saliva and tear secretion
Note mobility and facial symmetry as patient responds to your request to smile, frown, close eyes tightly (against your attempt to open them), lift eyebrows, show teeth, and puff cheeks - then press patient’s puffed cheeks in and note whether the air escapes equally from both sides
Only test sensory function when you suspect facial nerve injury - when indicated, test sense of taste by applying to the tongue a cotton applicator soaked in a solution of sugar, salt, or lemon juice (sour). Ask patient to identify the taste
What is cranial nerve 8, what does it do, and how do you test it?
Acoustic
Hearing and equilibrium
test hearing acuity by determining the patient’s ability to hear normal conversation or by the whispered voice test
What is cranial nerve 9, what does it do and how do you test it?
Glossopharyngeal
Pharynx (phonation and swallowing)
Taste on posterior one third of tongue, pharynx (gag reflex)
Parotid gland, carotid reflex
Depress the tongue with the tongue blade, and note pharyngeal movement as the patient says “ahhh” or yawns; the uvula and soft palate should rise midline, and the tonsillar pillars should move medially
Touch the posterior pharyngeal wall with a tongue blade and note the gag reflex - also note that the voice sounds smooth and not strained.
Sensory function - technically too difficult to test
what is cranial nerve 10, what does it do, and how do you test it?
Vagus
Pharynx and larynx (talking and swallowing)
General sensation from carotid body, carotid sinus, pharynx, viscera
Carotid reflex
Tested with cranial nerve 9, the glossopharyngeal nerve
What is cranial nerve 11, what does it do, and how do you test it?
Spinal
Movement of trapezius and sternomastoid muscles
Examine the sternomastoid and trapezius muscles for equal size. Check equal strength by asking the patient to rotate the head forcibly against resistance applied to the side of the chin. Then ask the patient to shrug the shoulders against resistance. These movements should feel equally strong on both sides
What is cranial nerve 12, what does it do and how do you test it?
Hypoglossal
Movement of tongue
Inspect the tongue. No wasting or tremors should be present. Note the forward thrust in midline as the patient sticks out the tongue. Also ask the patient to say “light, tight, dynamite” and note that lingual speech (sounds of letters l, t, d, n) is clear and distinct
How do you test cranial nerves 3, 4, and 6? (oculomotor, trochlear and abducens)
Check pupils for size, regularity, equality, direct and consensual light reactions and accommodation
Assess extraocular movements with the 6 cardinal positions of gaze
Endpoint nystagmus - a few beats of horizontal nystagmus at extreme lateral gaze - is normal
What areas do you need to assess in inspection and palpation of the motor system?
Muscles - for size, strength, tone, and any involuntary movements
Cerebellar function - balance tests (gait and the romberg test), coordination and skilled movements (rapid alternating movements, finger-to-finger test, finger-to-nose test, heel-to-shin test)
How do you assess the sensory system?
First, ensure the validity of sensory system testing by making sure that the patient is alert, cooperative, and comfortable, and has an adequate attention span;
Spinothalamic tract (pain, temperature, light touch)
Posterior column tract (vibration, position, tactile discrimination)
Inspect and palpate the motor system - muscles (size)
size - inspect all muscle groups for size, comparing right side with left; muscle group should be within normal limits for ages and should be symmetrical bilaterally; if extremities look asymmetrical, measure each in centimeters and record – a difference in 1 cm or less is not significant