CN tests Flashcards
Testing CN V: Facial sensation (light touch)
Test light touch with your finger or a cotton swab.
Lightly touch both sides of the patient’s forehead simultaneously. Ask
the patient if the sensation is equal or about the same on both sides. Lightly touch both sides of the patient’s cheek simultaneously. Ask
the patient if the sensation is equal or about the same on both sides. Lightly touch both sides of the patient’s chin simultaneously. Ask the
patient if the sensation is equal or about the same on both sides.
Normal Findings: Perception of light touch should be approximately equal bilaterally in all three regions tested
Testing CN V: Jaw Strength
Ask the patient to open their jaw.
Observe position of open jaw: midline or deviation to one side.
Ask the patient to move the jaw laterally to each side, one at a time,
while you try to resist the movement by pushing on the jaw with your hand. Observe and note whether the strength of jaw movement to each side appears approximately the same or is significantly more easily overcome on
one side.
Ask the patient to close their jaw tightly. Palpate both the masseter
muscles while the patient closes the jaw. Assess for symmetry of muscle bulk.
Normal Findings: The jaw should stay in the midline on opening without deviation to either side. Lateral jaw motion should feel symmetric and strong. The masseteric bulk should be symmetric.
Testing CN VII: Facial Strength
Ask the patient to smile.
Observe any weakness or obvious asymmetry of the mouth
movements. (With no abnormal findings, the test can end here.)
You may continue by asking the patient to raise their eyebrows. Observe symmetry in the forehead movement (and wrinkling).
Ask the patient to close their eyes tightly.
Look for any obvious asymmetry.
Assess the ability of the patient to resist your attempt to open their
eyes. Note the symmetry of strength of eye closure.
Normal Findings: There should be full and symmetric movements of the mouth, forehead and eye closure.
Testing CN II: Pupillary Light Reflex & Visual Pathway
Ask the patient to look straight ahead at a distant spot in a dim room. Observe the resting pupil for size and R-L symmetry. (Pupillary
diameter can be measured.)
Shine a bright light in one eye, approach the eye either laterally or
inferiorly to reduce the potential for accommodation by the patient.
Assess whether the pupil constricts to the light stimulus. Also observe
the other pupil for constriction response to the indirect light stimulus. Remove the light stimulus, wait a few seconds and move the light to
the other eye.
Assess whether the pupil constricts to the light stimulus. Also observe
the other pupil for constriction response to the indirect light stimulus.
Pupils are approximately symmetrical in size and shape. Each pupil should constrict to the direct light stimulus (direct
pupillary response) and the indirect light stimulus (consensual pupillary response).
Testing CN III: Visual Pathway
Stand or sit a few feet in front of the patient, with your head at approximately the same level as the patient’s, looking directly at the patient’s eyes.
Instruct the patient to look at your nose throughout the exam and cover one eye with one of their hands.
Ask the patient to count the number of fingers you are holding up.
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Anat 6512 Dr. E. Kalmar Sp17
Check the visual fields by holding your fingers first in front of the patient between you both, then in each of the four quadrants (R & L upper, R & L lower) of the visual field. Note: you will need to move your fingers more than 1 foot from the midline towards the periphery in each of the quadrants.
Repeat the test with the other eye covered.
Normal Findings: Patients should be able to count fingers in all four visual field quadrants of each eye.
Testing CN III, IV & VI: Eye movement tests, Testing CN VI: (See Eye movement test above)
Stand or sit in front of the patient looking directly at the patient’s eyes.
Hold up one index finger vertically between you and the patient at least 1 foot away from the patient in the patient’s midline.
Instruct the patient to follow your finger only using their eyes while keeping their head still. (Note: it may be helpful to gently rest your other hand on the patients head to help keep it still during the exam.)
Smoothly more your finger across to your right observing the patient’s horizontal eye movements toward the left.
Smoothly more your finger across to your left observing the patient’s horizontal eye movements toward the right.
Return your finger to the patient’s midline.
Change the orientation of your index finger to a horizontal position. From the patient’s midline smoothly move your finger up to assess the
patient’s upward eye movements.
Smoothly move your index finger down to assess the patient’s
downward eye movements.
You are making a large ‘H’ during this exam
Normal Findings: Each eye should move have the full range of motion in all directions of gaze tested. Both eyes should move together (i.e., conjugately) in parallel in all directions.
Testing CN IX: Gag reflex
You will need a tongue depressor and a flashlight.
Ask the patient to open their mouth while you depress the tongue
gently with a tongue depressor.
Gently touch the posterior arch or uvula with a cotton swab.
Observe if the is a gag reflex.
(Alternatively, you can also touch the tongue posterior to the terminal
sulcus clearly on one side and ask the patient on which side they feel the touch. Repeat for the other side.)
Normal Findings: A gag reflex is commonly observed. (Alternatively the patient should be able to distinguish on which side of the posterior tongue they were touched each time.)
Testing CN X: Palatal function
You will need a tongue depressor and a flashlight.
Ask the patient to open their mouth while you depress the tongue
gently with a tongue depressor.
Ask the patient to say “ah”.
Assess the elevation of the palate bilaterally and the position of the
uvula during the phonation.
Normal findings: Bilaterally symmetric elevation of the palate during phonation while the uvula remains in the midline. (Note: patients who have had tonsillectomies may have a normal asymmetry.)
Testing CN XI: Sternocleidomastoid & Trapezius strength
Ask the patient to rotate their head to one side. Hold your hand on
the patient’s chin, attempting to overcome the patient’s head turn by pushing toward the opposite side.
Repeat this action to the other side.
Ask the patient to shrug their shoulders upward. Push down on the patient’s shoulder while asking the patient to resist your downward pressure.
Normal Findings: There should be symmetric and strong resistance to your attempts to overcome the patient’s sternocleidomastoid and trapezius strength.
Testing CN XII: Tongue movement
Ask the patient to stick out their tongue.
Assess whether the tongue protrudes in the midline or deviates
unilaterally.
Observe the tongue to asymmetric atrophy.
Ask the patient to wiggle the tongue to one side and then the other. Inspect the tongue for fasciculations by asking the patient to relax the
tongue on the floor of the mouth with the tongue resting anteriorly against the lower (mandibular) teeth. Look at the tongue with a flashlight to assess for fasciculations.
Normal Findings: The tongue is approximately midline and does not deviate significantly during protrusion, moves well to each side and there is not atrophy or fasciculations.
