Peripheral Nervous System Experiments
Cranial Nerve Tests
The following experiments are designed to help identify the function of the twelve pairs of cranial nerves on a test subject.
1. CN I: Have the subject close their eyes. Using several Q-tips, dip a Q-tip in the following solutions to see if the subject can identify them by smell only. Suggested test solutions : Extracts such as vanilla, peperiment, lemon, or almond; cayenne pepper; bleach; spices such as garlic, sage, cloves, cinnamon, etc.
2. CN II: Take three objects of various sizes (small, medium, and large) and stand 20 feet away from the subject. Have the subject identify each object from 20 feet.
3. CN III, IV, VI: Using a pencil, have the subject visually observe and follow the pencil eraser as it is moved upward, downward, right, left, and in a circle.
4. CN V sensory: Have the subject close their eyes and touch the subject on the forehead, cheek, and chin using a cottonball. Have the subject confirm when they feel the stimulus.
5. CN V motor, CN IX, CN XII: Have the subject open their mouth, stick out their tongue. Using a popsickle stick or tongue depressor, push down on their tongue to observe the throat.
6. CN VII motor: Have the subject raise their eyebrows, squint, smile, and frown. CN VII sensory: Have the subject close their eyes and hold their nose closed. Using a Q-tip, dip the Q-tip in one of the extracts used in the CN I experiment and swab a small amount on the front half of their tongue. Note if the patient can identify the solution.
7. CN VIII hearing: Stand behind the subject and make various noises (clap, whistle, jingle coins, etc) for them to identify. CN VIII balance and equilibrium: Put one yard of masking tape on the floor and have the subject walk along the line. At the end of the tape, have the subject close their eyes and touch their nose with their index fingers. Repeat the walk and nose touch after the subject has been spun several times in a circle.
8. CN X: Have the subject seated, and record the number of breaths per minute. Using their wrist, find the radial artery to record their pulse during the next minute. If you have access to a stethoscope, listen to their heart beats and listen for any digestive track sounds.
9. CN XI: Have the patient shrug their shoulders and then lift one shoulder at a time.
Were you suprised by any of the results ? If so, why.
Cranial nerve tests are normally done during a physical exam. What possible information might they provide to the health care provider ?