Cranial Nerve Examination Nursing

During the head-to-toe nursing assessment, you will be assessing the cranial nerves. In this article, I want to break down how to assess cranial nerves I through XII (1-12) as a nurse.

Why do we assess cranial nerves? In short, to see if the neuron/nerve works!

Why wouldn’t a cranial nerve “work”? In many neuro diseases, the neurons that supply a particular nerve is damaged, which makes the nerve not function properly.

For example, in multiple sclerosis the myelin sheath of the neurons in the central nervous system are damaged, which leads to some sensory and motor problems. Many patients with MS can have speech and vision problems. The vision problems are from damage to the optic nerve that can lead to nystagmus, blurry vision, double vision etc. Therefore, you can assess this nerve (cranial nerve II) for any type of abnormalities.

Cranial Nerve Examination Video

Cranial Nerve Examination for Nurses During the Head-to-Toe Assessment

Cranial Nerve I

To test cranial nerve I..….olfactory nerve: Have the patient close their eyes and place something with a pleasant smell under the nose and have them identify it.

Cranial Nerve II

To test cranial nerve II….optic nerve: Perform the confrontation visual field test and visual acuity test with a Snellen chart.

Confrontation Visual Field Test

Assesses peripheral vision:

• Stand arm’s length from the patient.
• Cover your left eye, while the patient covers their right eye.
• Have the patient look at your nose (tell the patient NOT to look at your fingers)
• In the top and bottom of the visual field (test it with yours) hold up random numbers with your fingers and have the patient recite them back to you.
• Repeat again with the other eye (cover your right eye while the patient covers their left eye).

Visual Acuity: use a Snellen chart and have patient wear glasses or contact lenses if they normally wear them

• Have patient stand 20 feet from chart
• First the patient will cover the right eye, then left eye, and lastly read the chart with both eyes.
• Covering the right eye first, have the patient recite the lowest line they can read with ease.
• Repeat this with the left eye and then both eyes.

Results: If the patient can read line 8, their vision is 20/20, which means that the patient can see the same line of letters at 20 feet that a person with normal vision can see at 20 feet.

However, let’s say the patient can only read line 6 with the left eye, which means the patient has 20/30 in this eye. This means the patient can see at 20 feet what a person with normal vision can see at 30 feet.

Cranial Nerve III, IV, VI

To test cranial nerve III (oculomotor nerve), IV (trochlear), VI (abducens):

• Have the patient follow your pen light by moving it 12-14 inches from the patient’s face in the six cardinal fields of gaze (start in the midline)
  • Watch for any nystagmus (involuntary movements of the eye)

• Reactive to light?
  • Dim the lights and have the patient look at a distant object (this dilates the pupils)
  • Shine the light in from the side in each eye.
    • Note the pupil response: The eye with the light shining in it should constrict (note the dilatation size and response size (ex: pupil size goes from 3 to 1 mm) and the other side should constrict as well.

• Accommodation?
  • Make the lights normal and have patient look at a distant object to dilate pupils, and then have patient stare at pen light and slowly move it closer to the patient’s nose.
    • Watch the pupil response: The pupils should constrict and equally move to cross.

If all these findings are normal you can document PERRLA.

Cranial Nerve V

To test Cranial Nerve V…..trigeminal nerve: This nerve is responsible for many functions and mastication is one of them.

• Have the patient bite down and feel the masseter muscle and temporal muscle
• Then have the patient try to open the mouth against resistance

Cranial Nerve VII

• To test cranial nerve VII…facial nerve: have the patient close their eyes tightly, smile, frown, puff out cheek. Can they do this will ease?

Cranial Nerve VIII

To test cranial nerve VIII…vestibulocochlear nerve:

• Test the hearing by occluding one ear and whispering two words and have the patient repeat them back. Repeat this for the other ear.

Cranial Nerve IX and X

To test cranial nerve IX (glossopharyngeal) and X (vagus) have patient say “ah”…the uvula will move up (cranial nerve IX intact) and if the patient can swallow with ease and has no hoarseness when talking, cranial nerve X is intact.

Cranial Nerve XI

Test cranial nerve XI….accessory nerve: Have the patient move head from side to side and up and down and shrug shoulders against resistance.

Cranial Nerve XII

Test cranial nerve XII….hypoglossal: have patient stick tongue out and move it side to side

More nursing skills