Cranial Nerve Examination Flashcards
What is it useful to do when examining an older child?
Consider each area of the nervous system individually - the cranial nerves, cerebellum, upper limb, lower limb, and gait
What is cranial nerve I (1)?
Olfactory
What is cranial nerve II (2)?
Optic
What is cranial nerve III (3)?
Oculomotor
What is cranial nerve IV (4)?
Trochlear
What is cranial nerve V (5)?
Trigeminal
What is cranial nerve VI (6)?
Abducens
What is cranial nerve VII (7)?
Facial
What is cranial nerve VIII (8)?
Vestibulocochlear
What is cranial nerve IX (9)?
Glossopharyngeal
What is cranial nerve X (10)?
Vagus
What is cranial nerve XI (11)?
Accessory
What is cranial nerve XII (12)?
Hypoglossal
What does CN 3 innervate?
- Ciliary muscles
- Sphincter of pupils
- All external muscles of eye except superior oblique and lateral rectus
What does CN 4 innervate?
Superior oblique muscle
What does CN 5 innervate?
Sensory to face, sinuses, and teeth
What does CN 6 innervate?
Lateral rectus muscle
What does CN 7 innervate?
Muscles of face
What does CN 7 innervate via the intermediate nerve?
- Motor to submandibular, sublingual, and lacrimal glands
- Taste to anterior 2/3 of tongue
- Sensory to soft palate
What does CN 8 divide into?
- Cochlear nerve
- Vestibular nerve
What does CN 9 innervate?
- Taste to posterior 1/3 of tongue
- Sensory to tonsils, pharynx, and middle ear
- Motor to stylopharyngess, upper pharyngeal muscle, and parotid gland
What does the CN 10 innervate?
- Motor to heart, lungs, palate, pharynx, larynx, trachea, bronchi, and GI tract
- Sensory to heart, lungs, trachea, bronchi, larynx, pharynx, GI tract, external ear
What does CN 11 innervate?
- Sternocleidomastoid
- Trapezius
What does CN 12 innervate?
Tongue
How is CN 1 tested?
Asking patient if they have noticed any change in their sense of smell
If test done, each nostril in turn
How is CN 2 tested?
- Visual acuity
- Visual fields
- Pupillary reflexes
- Fundoscopy
What pupillary reflexes should be tested?
Direct and consensual responses to lift, then accommodation
How should CN 3, 4, and 6 be tested?
Ask child to fix and follow on an object (light from pen torch is best in children)
How should the motor component of CN 5 be tested?
- Ask child to open their mouth whilst you try and close it
- Clench teeth together and feel muscle mass of masseters
What will be found when you ask the child to open their mouth whilst you try to close in if there is a CN 5 lesion?
It will deviate to the side of weakness
What divisions provide the sensory functions of CN 5?
- Opthalmic
- Maxillary
- Mandibular
How should you assess the sensory functions of CN 5?
Test each division and compare both sides
Should you test the corneal reflex?
No
How should you assess the motor component of the CN 7?
Ask child to close their eyes tightly, open their eyes really wide, blow out their cheeks, and show their teeth
How should you assess CN 8?
Rinne’s and Weber’s test
How should you assess CN 9 and 10?
Ask child to open their mouth and say ‘ahh’ whilst looking at palatal movement
How should you assess CN 11?
Ask the child to shrug their shoulders, turn their head to the right, and place a hand on the left side of their face and ask to push against your hand
How should you assess CN 12?
Ask the child to stick out their tongue and inspect for fasciculation and deviation
What will be found on examination if there is a lesion of CN 12?
The tongue deviates to the side of the lesion
