1. Introduction
The cranial nerve examination assesses the function of cranial nerves I to XII. In undergraduate OSCEs it is often focused on nerves II to XII, with olfaction mentioned as a completion step unless there is a specific indication.
2. General inspection
Begin with hand hygiene, introduction, identity check, explanation and consent. Position the patient sitting upright. Inspect for facial asymmetry, ptosis, abnormal head posture, hearing aids, obvious involuntary movements and dysarthria.
3. Optic nerve
Assess visual acuity in each eye if equipment is available, check visual fields by confrontation, inspect pupils and test direct and consensual light reflexes. Assess the accommodation reflex if relevant. Fundoscopy is usually a completion step unless specifically requested.
4. Eye movements
Test extraocular movements in an H pattern, assessing for diplopia, nystagmus and limitation of movement. Look for ptosis and pupillary abnormalities that may suggest a third nerve palsy or Horner syndrome.
5. Trigeminal and facial nerves
Assess the muscles of mastication by palpating masseter and temporalis as the patient clenches their teeth. Test facial sensation in the ophthalmic, maxillary and mandibular distributions if indicated. Check facial movements including eyebrow raise, eye closure, smiling, showing teeth and puffing out cheeks.
6. Hearing, palate and tongue
Assess hearing with a whisper test, then use Rinne''s and Weber''s tests if hearing loss is suspected. Ask the patient to say ahh and inspect palate movement and uvula position. Assess shoulder shrug and head turn against resistance and inspect the tongue for wasting or fasciculation before asking the patient to protrude it.
Preparation
General inspection
Cranial nerve II
Cranial nerves II and III
Cranial nerves III, IV and VI
Cranial nerve V
Cranial nerve VII
Cranial nerve VIII
Cranial nerves IX and X
Cranial nerve XI
Cranial nerve XII
Completion