i am a very visual and kinesthetic learner, so i learn best by looking at pictures and for the cranial nerves i learned best by practicing the different tests for the nerves. here are some of the things that helped me with them. to see the pictures copy the websites into your address bar.
1. i olfactory nerve i remember the 1st and 2nd cranial nerves because we have 1 nose and 2 eyes. also as the 1st cranial nerve is the olfactory nerve i think of the nose being able to “smell” the smoke stacks from the” factories” in our city.
- 2, 3, 4, and 6 all control the eyes
- ii “optic nerve” helps us see – think of the “optic-ian” they make glasses for us to see.
- we practiced these 3 tests:
- visual acuity with eye chart
- peripheral vision with confrontation test
- looked at “optic disk” in the eye with the opthalmascope to see size, shape and color.
- visual acuity test have the patient read the snelling eye chart to determine 20/20 vision or not.
- confrontation test which tests peripheral vision – the examiner and patient face each other and one covers their right eye the other their left eye. the examiner stretches out her arm and moves her finger toward their covered eyes until the finger can be seen in the peripheral vision. the examiner confronts the patient to say “now” when she can see the examiners finger in peripheral vision. the patient says “now” when she can see the finger in peripheral vision which should be at the same point the examiner can see her finger in peripheral vision.
iii oculomotor constricts the pupils (cn ii and cn iii play a part in constricting the pupils)
- (we learned perrla for pupils, equal, round, reactive to light and accomodation)
- test “pupillary light reflex” by dimming the lights in the room and shining a penlight or flashlight quickly at the eye and observe the pupil. the pupil should constrict or get smaller in an effort to reduce the bright light that is shining at the eyes.
- accomodation is a test where you hold one finger out in front of the nose. at this point the pupils will be dilated normal. then move the finger right up close in front of the nose and the pupils accommodate for how close the object – your finger is and the pupils constrict or get smaller.
- iv trochlear moves the eyes up and down
- 6 cardinal positions of gaze is not a test specific to cn iv but it is a test we practiced to test all the eye muscles or eom (extra ocular muscles)
- this test the examiner just moves their finger in front of the patient while the patient tracks their finger with their eyes. this can show if there is weakness of the eye muscles or problems with one of the cn’s that work the eye muscles.
- v trigeminal nerve – this i remember because we did ( three – hence” tri”) tests for this. also if you look at a picture of where the nerves originate in the brain you see the three nerves right in a row.
- tested for gentle touch of the forehead or face with a cotton ball
- tested for reflex or blinking by moving the cotton ball close to the eye
- tested for chewing and use of muscles
6. vi abducens – abducts and adducts the eyes or moves them side to side.
- we learned adduct means to add or bring towards the body or towards the middle and then abduct means the opposite so that is away from the body. or in this case that would move the eyes side to side.
7. vii facial nerve – tests muscles used in facial expression. bell’s palsy or facial palsy (a droop of one side of the face) is a problem of cranial nerve vii. and cn vii tests taste on the front of the tongue.
8. viii acoustic nerve or (vestibulocochlear) this one is easy to me as i know that acoustic or cochlear both are related to hearing. also is involved with balance.
9. ix glossopharyngeal – pharyngeal sounds like laryngeal which i know refers to the throat and swallowing and talking. also tests taste on the back of the tongue or closer to the throat.
10. x vagus nerve is the wandering nerve or the cranial nerve that travels far. (affects glands digestion and heart rate.) i don’t know why but this always makes me think of las vegas and all the different people who travel far to go there.
11. xi accessory nerve – all the cranial nerves are tested by examining a specific area on the head, except for the vagus wandering nerve and this accessory nerve. so to test for this nerve you test an accessory to the head.
- the test we did for this nerve is to have the patient lift their shoulders. the action of lifting the shoulders makes me think of the number 11. both shoulders moving up and then down. some tilt the head from side to side to test this nerve as well. it is actually testing the trapezium muscle and the sternomastoid muscle.
12. hypoglossal – this one is easy too. hypo means below, glossal means the tongue. we were testing tongue movement or whether the patient can lift up or stick out their tongue so we can see below the tongue or see the hypoglossal area.
a mnemonic for remembering the order of the 12 cranial nerves
“on old olympus towering tops a fin and german viewed some hops”
a mnemonic to remember if the cranial nerve is a sensory nerve, motor nerve or both.
“some say marry money
, but my brother says bad business marry money”