CN exam Flashcards
What is cranial nerve I called?
Olfactory
What is cranial nerve II called?
Optic
What is cranial nerve III called?
Oculomotor
What is cranial nerve IV called?
Trochlear
What is cranial nerve V called?
Trigeminal
What is cranial nerve VI called?
Abducens
What is cranial nerve VII called?
Facial
What is cranial nerve VIII called?
Vestibulocochlear
What is cranial nerve IX called?
Glossopharyngeal
What is cranial nerve X called?
Vagus
What is cranial nerve XI called?
Accessory
What is cranial nerve XII called?
Hypoglossal
How would you test CNI?
“Have you noticed any change in your sense of smell recently?”
“I would normally test this using smelling tubes to differentiate the smell in the each nostril but I won’ t be doing that now”
What do you need to assess to test CN II?
AFRO BC: Acuity visual Fields Reflexes (light and accommodation) Ophthalmoscopy
Blind spot
Colour vision
How do you assess acuity?
Snellen chart
How do you use a Snellen chart?
6M from chart, test corrected and uncorrected vision in each eye. If can’t seee –> 3M –> hand waving –> light perception
How do you assess a patient’s blind spot?
Using a red hat pin
What are you looking for on assessment of CN III, IV and VI?
Nystagmus
Diplopia- Vertical? Horizontal? Ask if the second image disappears when covering up each eye
What muscles are innervated by CNIII?
Superior rectus, inferior rectus, medial rectus and inferior oblique. Levator palpebrae superioris
What muscles are innervated by CNIV?
Superior oblique (LR6SO4)
What muscles are innervated by CNVI?
Lateral rectus (LR6SO4)
What are the 3 major components of CNV?
Motor, sensory and reflex
What is the significance of the jaw jerk?
Differentiates between a bulbar and pseudo-bulbar palsy
What are the afferent and efferent components of the corneal reflex?
Afferent: V1 (ophthalmic division of trigeminal)
Efferent CN VII
What are the divisions of the trigeminal nerve?
V1- ophthalmic
V2- maxillary
V3- mandibular
What are the afferent and efferent components of the jaw jerk?
Afferent- V3 (mandibular division)
Efferent- motor CNV
How would you tell if a facial nerve palsy was upper or lower motor neurone?
Forehead involvement- forehead sparing –> UMN
Why is the forehead spared in UMN lesions of CNVII?
Due to bihemispheric innervation. Other aspects of CNVII only receive contralateral innervation from the pyramidal tract
Why can a facial nerve palsy result in hyperacusis?
As CNVII provides LMN innervation to the muscles of stapedius
What two effects of CNVIII do you need to test in a CN exam?
Hearing and balance
How many gag reflexes are there?
2- right and left
When you ask a patient to shrug their shoulders against resistance which muscle are you testing?
Trapezius
When you ask a patient to shrug their shoulders against resistance which nerve are you testing?
Accessory (CNXI)
