Cranial Nerves

There are different ways to perform a cranial nerve examination. This is one example of a structured examination.

 

Equipment

  1. Snellen chart

  2. Pen torch

  3. Ishihara plates

  4. Cotton wool

  5. Tuning fork (512 Hz)

  6. Cup of water

  7. Tongue depressor

Introduction

 

  • Wash hands with alcohol gel

  • Introduce yourself to the patient

  • Confirm patient’s name and date of birth

  • Obtain consent to examine the patient and explain what this will involve

  • Ask for a chaperone if required

  • Position patient – sit in chair

  • Ask the patient if they have any pain

  • Gather equipment 

 

I – olfactory nerve

Ask if the patient has noticed any change in their sense of smell

Suggest you would assess smell formally using smell test e.g. UPSIT – University of Pennsylvania smell test

 

II – optic nerve

Inspect pupils – size, shape, symmetry

Assess visual acuity using Snellen chart

Pupillary response with pen torch

Direct and consensual

Swinging light test

Accommodation reflex

Colour vision using Ishihara plates

Assess visual fields by direct confrontation

Suggest that you would assess eye using fundoscopy

 

III – oculomotor, IV – trochlear, VI – abducens nerves

Assess movement of eyes by asking patient to following your finger with just their eyes

Ask for any diplopia

 

 

V – trigeminal nerve

Assess sensation of all 3 areas supplied by trigeminal nerve

V1: ophthalmic branch – Forehead 

V2: maxillary branch – cheek

V3: mandibular branch – mandible

Use fine touch with cotton wool and pinprick sensation with neurotip

Compare left side with right side for all areas

Assess motor function by asking patient to clench teeth

Palpate masseter and temporalis muscles 

Suggest assessing the jaw jerk reflex

 

 

VII – facial nerve

Inspect patient for any obvious asymmetry of the face

Assess facial movement – ask patient to 

Raise eyebrows

Close eyes tight and assess power

Scrunch nose

Blow out cheeks and assess power

Show their teeth

 

VIII – vestibulocochlear nerve

Gross hearing test using free field testing

Rhines and Weber’s tuning fork test

Suggest you would request formal audiometry – pure tone audiogram

 

IX – glossopharyngeal nerve, X – vagus nerve

Assess soft palate and uvula – asymmetry

Observe for deviation of uvula (deviates away from side of lesion)

Ask patient to swallow sip of water

Ask patient to cough

Suggest you would assess for the gag reflex

 

XI – accessory nerve

Ask patient to shrug their shoulders whilst applying resistance down (trapezius)

Ask patient to turn head to side whilst applying resistance to opposite side (sternocleidomastoid)

 

XII – hypoglossal nerve

Inspect tongue for asymmetry, fasciculations and wasting

Ask patient to protrude tongue (deviates towards side of lesion)

 

 

To complete examination 

Suggest full neurological examination including gag reflex, corneal reflex, taste and smell

Thank patient for examination

Wash your hands

Present findings

Suggest that you would document your findings in the patient’s notes

 

Possible investigations that may subsequently be requested

CT /MRI head

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