How to Test the Trigeminal Nerve

The trigeminal nerve belongs to a group of 12 pairs of nerves known as the cranial nerves. They perform various sensory and motor functions throughout the head, face, neck and body. The trigeminal nerve acts as the fifth cranial nerve and consists of three branches: the ophthalmic, maxillary and mandibular. The nerve has both motor and sensory functions. The motor part of the trigeminal nerve controls the muscles responsible for chewing, while the sensory parts of the nerve branches deliver information about touch and pain from the face. You can conduct a basic test of these functions quite easily.

Things You'll Need

• Cotton ball

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Instructions

• 1

  Tell the test subject to clench her jaw as if she were chewing on a piece of gum. The trigeminal nerve controls the chewing muscles, so this action tests the motor function for both sides of the face simultaneously.

• 2

  Tell the subject to close his eyes. The sensory part of the test involves touch, and should take place blindly.

• 3

  Tell the subject to indicate when she feels something touching her face and touch the cotton ball to either side of her face. Take note of her response, and continue touching different parts of her face until you have touched both sides of her jaw, both cheeks and both sides of the forehead.