Cranial Nerve Examination Flashcards
To memorise the steps for each cranial nerve exam
What should you start the whole examination with? (4)
- Wash hands
- Introduce yourself (full name and position)
- Identify the patient (full name, DOB and hosp no.)
- Gain consent to perform exam
What do you look for in the general inspection of head and neck?
Scars Neurofibromas Facial assymetry Ptosis Proptosis Skew deviation of the eyes Inequality of pupils
How do you test cranial nerve 1?
Olfactory:
only usually tested if patient reports abnormal sense of smell - ask!
Olfactory testing bottles on each nostril separately while occluding contralateral nostril - no noxious substances! (stimulate pain fibres in CNV)
What are the 5 ways of testing cranial nerve 2?
Optic: Visual acuity Visual fields Visual inattention/visual extinction Direct and consensual light reflexes Accomodation
How would you test visual acuity?
Snellen chart
OR
Cover one eye and state how many fingers holding up
How would you test visual fields?
Sit opposite patient with eyes at same level and 1m gap. Cover one eye and ask them to cover their eye opposite your covered eye. Use object (index finger) and bring from point outside your own visual field diagonally towards centre of visual field. Ask patient to tell you when they first see the object. Repeat in all 4 quadrants and test both eyes
How would you test visual inattention/extinction?
Hold hands up in periphery of their visual field (one on each side). Move tip of index finger on one side and then the other and then both at the same time. Ask patient to tell you which side is moving. Visual inattention is when they an detect each side individually but not at the same time
How do you test direct and consensual light reflexes?
Ask patient to look straight ahead
Bring light source from side (so patient does not accommodate)
Look for constriction of pupil on same side as light (direct) and on the contralateral pupil (consensual)
How do you test accommodation?
Ask patient to focus on distant point and then to focus on your finger (approx 30 cm in front of face). Normal response pupil constriction on both sides.
How would you test cranial nerves 3, 4 and 6?
Oculomotor, Trochlear and Abducens:
Keep head still and follow finger with eyes - H shape and central I shape
Take eyes to limit of gaze
Observe for any dysconjugate eye movements or nystagmus
Ask if experience any diplopia
How would you test cranial nerve 5?
Trigeminal:
SENSATION - use cotton wool in ophthalmic, maxillary and mandibular regions with eyes closed. Test first on sternum with eyes open. Ask if difference between 2 sides in strength of sensation
MOTOR - Clench teeth and palpate masseter and temporalis muscles
Open mouth against resistance
Jaw jerk - mouth half open and tendon hammer to chin (abnormal response - mouth will shut rapidly)
How would you test cranial nerve 7?
Facial nerve: Screw eyes up Raise eyebrows Puff out cheeks Purse lips Show teeth (forehead sparing shown in UMN lesions)
How would you test cranial nerve 8?
Vestibulocochlear:
Cover opposite ear and whisper in one ear - ask patient to repeat
If concerned about abnormality, perform Rinne’s or Weber’s tests to determine if sensorineural or conductive hearing loss
Vestibulo-ocular reflex if dizzy
How would you test cranial nerves 9 and 10?
Glossopharyngeal and Vagus:
Open mouth wide and say “aah” - uvula should be in midline and not deviate or have assymetrical movement
Ask if have difficulty swallowing
Ask patient to cough (bovine/non-explosive = vagal palsy)
Any hoarseness in voice?
How would you test cranial nerve 11?
Accessory:
Shrug shoulders against resistance - trapezius
Turn head against resistance whilst palpating sternomastoid with free hand
