cranial nerve examination

Question 1

what cranial nerve is affected in Bell’s palsy

Answer 1

7

Question 2

why might the head be tilted in a cn 4 lesion

Answer 2

paralysis of superior oblique which brings eye inwards and down
this causes the patient to compensate by lifting the eye away from the side of the lesion

Question 3

what is the main nerve that supplies taste

Answer 3

7

Question 4

what nerve identifies irritant odors

Answer 4

5 (not 1)

Question 5

what nerve is tested for when you ask the patient about walking downstairs

Answer 5

occulomotor/ trochlear

Question 6

what does a skewed position of the eyes suggest

Answer 6

lesion of the medial longitudinal fasciculus ( carries information about the direction that the eyes should move)

Question 7

what type of ptosis is found in horner’s

Answer 7

partial always

Question 8

what type of ptosis is found in third nerve palsy

Answer 8

may be partial but is usually complete

Question 9

what are some other causes of ptosis

Answer 9

congenital, myasthenia gravis

Question 10

what is the innervation of levator palpebrae superioris

Answer 10

occulomotor and also sympathetic

Question 11

what does miosis mean

Answer 11

small pupil

Question 12

what is enopthalmos

Answer 12

partial backwards displacement of the eyeball

Question 13

how do you use a snellen chart

Answer 13

ask patient to read the lowest line down possible
from 6m away
can wear corrective glasses

Question 14

what should you do if they cant read the top line

Answer 14

can the count fingers/ recognise hand movements or see light

Question 15

what are limbs of the light reflex (pupil constricts in response to light)

Answer 15

optic nerve afferent

psymp of occulomotor is efferent

Question 16

what is the parasympathetic supply to the pupil controlled by

Answer 16

edinger westphal nucleus

Question 17

what does the consensual response mean

Answer 17

the pupil on the opposite side to that which light is being shone in constricts

Question 18

what are Argyll Robertson pupils

Answer 18

accommodate but do not react to light

caused by neurosyphilis

Question 19

how far away from the patient should you place your finger when testing accommodation reflex

Answer 19

50 cm

Question 20

what mediates the accommodation reflex

Answer 20

afferent- optic (

efferent- oculomotor (psymp from edinger westphal)

Question 21

what parts of the brain ensure that both eyes move together

Answer 21

frontal and occipital lobes
cerebellum and vestibular nuclei
integrated in the brainstem
medial longitudinal fasciculus

Question 22

where is the medial longitudinal fasciculus found

Answer 22

runs between nuclei of 3 and 4 in the midbrain and 6 in the pons

Question 23

what supplies superior oblique

Answer 23

4

Question 24

what supplies lateral rectus

Answer 24

6

Question 25

what muscles elevates the eye

Answer 25

superior rectus and inferior oblique

Question 26

what muscles depress the eye

Answer 26

inferior rectus and superior oblique

Question 27

what is the function of superior oblique

Answer 27

depresses, abducts and intorts the pupil (crosses eyes)

Question 28

what is the function of inferior oblique

Answer 28

elevates, abducts and extorts the pupil

Question 29

where can lesions be found

Answer 29

``` supranuclear internuclear (mlf) nuclear nerve nmj muscle ```

Question 30

what part of the brain controls eye pursuit

Answer 30

occipital lobe | patient tracks a moving target

Question 31

how is nystagmus described

Answer 31

in the direction of the fast phase

Question 32

what can cause peripheral nystagmus

Answer 32

vestibular system abnormalities | eight cn or nucleus

Question 33

what causes retinal nystagmus

Answer 33

damage to the retina so inability to fix on an image

Question 34

eye deviated laterally and slightly downward, pupil may be dilated and unresponsive, ptosis

Answer 34

cn 3 paresis

Question 35

impaired depression of the fully adducted eye, head may be tilted to the opposite side to avoid diplopia

Answer 35

cn 4

Question 36

impaired abduction

Answer 36

cn 6

Question 37

what are the limbs of the corneal reflex

Answer 37

afferent- cn 5 efferent - cn 7 pt should blink

Question 38

when you ask the patient to open their mouth against resistance, what muscle are you testing

Answer 38

pterygoids

Question 39

if the lower jaw deviates to the left what does this suggest

Answer 39

left sided paralysis | lesion of the trigeminal nerve

Question 40

what are the limbs of the jaw jerk reflex

Answer 40

both are 5 proprioception travels to the mesencephalic nucleus (midbrain) then go to pontine motor nucleus then to muscles of mastication

Question 41

what does an abnormally brisk jaw jerk reflex suggest

Answer 41

bilateral upper motor neurone lesions affecting the corticobulbar pathway

Question 42

what is bulb another name for

Answer 42

medulla

Question 43

what muscles are being tested when pt is asked to grimace and show me your teeth

Answer 43

platysma and dilators

Question 44

say me me me

Answer 44

lips and front of mouth tested

Question 45

puff out your cheeks and don't let me push them in

Answer 45

orbicularis oris

Question 46

how do you differentiate between an upper and lower motor neurone lesion of the facial nerve

Answer 46

in an UMN lesion frontalis and orbicularis oculi are usually spared in a lower motor neurone lesion the lower and upper part of the face are paralysed

Question 47

bell's palsy

Answer 47

swelling of the facial nerve withing the facial canal | may be hyperacusis

Question 48

what is Bells phenomenon

Answer 48

eyeball turned upwards when the patient closes their eyes

Question 49

what supplies taste in the anterior 2/3 of tongue

Answer 49

chorda tympanii from the facial nerve

Question 50

what is webers hearing test

Answer 50

tuning fork is held on the forehead

Question 51

what is rinnes test

Answer 51

tuning fork is held on the mastoid tests for conductive deafness- bone conduction is better than air

Question 52

what does it suggest if the uvula moves to the left side

Answer 52

there is a lesion of the vagus on the right side

Question 53

parotid secretions and taste on posterior tongue

Answer 53

glossopharyngeal

Question 54

what is the cranial accessory nerve

Answer 54

arises from the caudal extension of the nucleus ambiguous and joins the vagus

Question 55

how is visual acuity calculated

Answer 55

distance at which test is performed in meters / line number that was read successfully