The following document was written by Mr Vik Veer MBBS(lond) MRCS(eng) DoHNS(eng) in Dec 2007. You may use the information here for personal use but if you intend to publish or present it, you must clearly credit the author and
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Examination of the Cranial Nerves

The following document is one way of examining the cranial nerves. There are obviously many ways and techniques to do this which aren't mentioned here. I suspect you will only use this as a guide to your own examining technique which you should evolve to suit your own approach and style. I have also assumed that you have some knowledge of medicine throughout this examination. If you are uncertain to the reasons why i have mentioned things in my examination or need clarification there are some excellent books you can refer to.

I have written this with the idea that this will be used in an exam setting - so you will be presenting your findings as opposed to a clinic setting. i would try and talk constantly whilst examining the patient. It keeps the examiner interested and shows off what you know.


– introduce yourself and explain what you would like to do, then ask for permission.

I — Olfactory Nerve

"Have you noticed any change in your sense of smell?"

Testing formally involves using smells such as coffee, peppermint, vanilla in each nostril separately. Remember that noxious smells can be picked up by the trigeminal nerve. If the patient claims they can’t smell anything ask them if they are able to smell petrol (trigeminal nerve)

II — Optic Nerve

Visual acuity — use a Snellen chart 6 meters away, and with each eye separately find the smallest line of print that the patient can read. Allow the patient to wear glasses if they have them. Record the results (6/18 = at 6 meters the patient is only able to read print that normal can be read at 18 meters.)

Colour Vision — 15 Ishihara test plates at 75cm from the patient. 13+/15 is considered to be normal. If you want to try an online version try this Visual Inattention — stand a meter away and then hold up both your index fingers 50cm away from both you and the patient. Make sure that your fingers are separated approximately by the width of your shoulders and that the patient is staring at your nose only. Then move each finger and ask the patient to call out if he/she can see them moving. In parietal lobe lesions (particularly in the non-dominant hemisphere) a isolated stimulus is perceived however it is missed when a comparable stimulus is presented contralaterally.

Visual Fields — sit 1 meter from the patient, eyes level, and ask him to close one eye (you do the same) then put your hand to the extremes of your vision in the four quadrants (NE, SE, NW, SW) and move in towards the center until the patient can see it. Use a moving index finger for the outer visual fields and make sure that the patient's eye remains fixed on your own. To assess central visual field defects use a small coloured object as the moving finger is too crude. Start by assessing the blind spot and then scan over the central area on each eye.


optic tracts with pathology

III - Oculomotor, IV – Trochlear, VI – Abducens


Horner's syndrome - unilateral pupillary constriction, slight ptosis, enophthalmos, (sweating on the affected side of the face.

Argyll Robertson Pupil - small irregular pupil which is not reactive to light but will have a accommodation reflex. (tip to remember - think of 'she's a prostitute - she'll accommodate - but she won't react')

Holmes-Adie pupil (myotonic)- large pupil with a sluggish reactions to light and accommodation. Associated with absent tendon reflexes in women.

Eye Movements


Nystagmus – an involuntary rhythmical oscillatory movement of the eyes.

V – Trigeminal Nerve

Motor component Senosory component

VII – Facial nerve

"have you noticed any change in your sense of taste?"

- formal testing would involve using sweet, sour, salt on the anterior 2/3 of the tongue.

"have you noticed that noises seem excessively loud in one ear rather than the other?"

– facial nerve supplies the stapedius muscle of the middle ear which reduces conduction of very loud noises through the ear.

"Do any of your eyes seem dry to you?"

– facial nerve provides innervation (at least part of the way) of the lacrimal gland which produces tears.

Muscles of facial expression

lift your eyebrows high in the air – frown – squeeze your eyes shut – don't let me open them

(try and open their eyes with your fingers – they should be strong enough to resist you)

Show me all your teeth - blow your cheeks out

(no air should escape through the lips on maximal inflation)


Lower motor neuron facial weakness – global weakness of one side of the face.

Upper motor neuron facial weakness – the frontalis muscle is normally unaffected as it has a dual nerve supply from both hemispheres.

VIII – Vestibular/Cochlear – Acoustic Nerve

- (see Ear examination for more detail) Auditory function – test each ear separately by rubbing your fingers together or listening to your watch tick. Rinne's test – use a 512 Hz tuning fork and place it on the mastoid process and then again near the pinna –' Where does the tuning fork sound loudest, here or here?"

Weber's test – place the same fork at the midline vertex and ask "Which ear can you hear the tuning fork in, or are they both the same?"

With sensorineural hearing loss the sound is heard more in the non affected ear. With conductive loss the sound localises on the affected side.

Vestibular function

"do you experience any vertigo or dizziness – when you get dizzy does the world is spin around you?"

IX – Glossopharyngeal Nerve

"For the glossopharyngeal nerve I would test the gag reflex by placing an orange stick on the posterior wall of the pharnyx and watch for the palate to rise in the midline".

try and avoid doing this in the exam as it isn’t pleasant for the patient.

X – Vagus Nerve

"Would you swallow some water for me please"

"Say 'Ah' for me please"

– the palate and the uvula are pulled up equally. Also you can notice any dysphonia from paralysis of either of the recurrent laryngeal nerves.

XI – Accessory Nerve

Inspect for any muscle wasting.

Turn your head left and right

(hold their chin to test power). (Testing power of the sternocleidomastoid muscles)

"Shrug your shoulders up - don't let me push them down"

– testing the trapezius.

XII – Hypoglossal Nerve

"Stick your tongue out for me."

Tongue leans towards the defective side.


Ask to complete the neurological examination by testing the peripheral nerves and any other system if you think this is relevant.

There are very good online guides for this subject - such as:


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