Cranial Nerve Examination

There are 12 pairs of nerves that come from the brain, one for each side of the brain.  One or more of the nerves can be affected depending on what is the cause.  Common conditions include space occupying lesions (tumours or aneurysm), myasthenia gravis and multiple sclerosis, although there are many more.

For a detailed list visit this site.

The cranial nerve examination involves a number of steps as you are testing all 12 of the nerves in one station. Be certain to know which nerve is being tested next and what tests you must perform for each specific nerve.

This guide will take you through each nerve systematically, but personal techniques may be adopted for this station so that it flows best for you.  It can seem like a daunting station as there are many steps to it but hopefully this guide will help.

Subject steps

  1. The Optic nerve (CN II) is tested in five ways:

    • Acuity
    • Colour
    • Fields
    • Reflexes
    • Fundoscopy
  2. As previously mentioned the Abducent nerve (CN VI) is tested in the same manner as the oculomotor and trochlear nerves, again in eye movements.

  3. The Vagus nerve (CN X) provides motor supply to the pharynx.

    Asking the patient to speak gives a good indication to the efficacy of the muscles. The uvula should be observed before and during the patient saying “aah”. Check that it lies centrally and does not deviate on movement.

  4. Thank your patient and wash your hands. Report any findings to your examiner.