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Flashcards in cranial nerve examination Deck (55):
1

what cranial nerve is affected in Bell's palsy

7

2

why might the head be tilted in a cn 4 lesion

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

3

what is the main nerve that supplies taste

7

4

what nerve identifies irritant odors

5 (not 1)

5

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

occulomotor/ trochlear

6

what does a skewed position of the eyes suggest

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

7

what type of ptosis is found in horner's

partial always

8

what type of ptosis is found in third nerve palsy

may be partial but is usually complete

9

what are some other causes of ptosis

congenital, myasthenia gravis

10

what is the innervation of levator palpebrae superioris

occulomotor and also sympathetic

11

what does miosis mean

small pupil

12

what is enopthalmos

partial backwards displacement of the eyeball

13

how do you use a snellen chart

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

14

what should you do if they cant read the top line

can the count fingers/ recognise hand movements or see light

15

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

optic nerve afferent
psymp of occulomotor is efferent

16

what is the parasympathetic supply to the pupil controlled by

edinger westphal nucleus

17

what does the consensual response mean

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

18

what are Argyll Robertson pupils

accommodate but do not react to light
caused by neurosyphilis

19

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

50 cm

20

what mediates the accommodation reflex

afferent- optic (
efferent- oculomotor (psymp from edinger westphal)

21

what parts of the brain ensure that both eyes move together

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

22

where is the medial longitudinal fasciculus found

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

23

what supplies superior oblique

4

24

what supplies lateral rectus

6

25

what muscles elevates the eye

superior rectus and inferior oblique

26

what muscles depress the eye

inferior rectus and superior oblique

27

what is the function of superior oblique

depresses, abducts and intorts the pupil (crosses eyes)

28

what is the function of inferior oblique

elevates, abducts and extorts the pupil

29

where can lesions be found

supranuclear
internuclear (mlf)
nuclear
nerve
nmj
muscle

30

what part of the brain controls eye pursuit

occipital lobe
patient tracks a moving target

31

how is nystagmus described

in the direction of the fast phase

32

what can cause peripheral nystagmus

vestibular system abnormalities
eight cn or nucleus

33

what causes retinal nystagmus

damage to the retina so inability to fix on an image

34

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

cn 3 paresis

35

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

cn 4

36

impaired abduction

cn 6

37

what are the limbs of the corneal reflex

afferent- cn 5
efferent - cn 7

pt should blink

38

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

pterygoids

39

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

left sided paralysis
lesion of the trigeminal nerve

40

what are the limbs of the jaw jerk reflex

both are 5

proprioception travels to the mesencephalic nucleus (midbrain)

then go to pontine motor nucleus

then to muscles of mastication

41

what does an abnormally brisk jaw jerk reflex suggest

bilateral upper motor neurone lesions affecting the corticobulbar pathway

42

what is bulb another name for

medulla

43

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

platysma and dilators

44

say me me me

lips and front of mouth tested

45

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

orbicularis oris

46

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

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

47

bell's palsy

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

48

what is Bells phenomenon

eyeball turned upwards when the patient closes their eyes

49

what supplies taste in the anterior 2/3 of tongue

chorda tympanii from the facial nerve

50

what is webers hearing test

tuning fork is held on the forehead

51

what is rinnes test

tuning fork is held on the mastoid

tests for conductive deafness- bone conduction is better than air

52

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

there is a lesion of the vagus on the right side

53

parotid secretions and taste on posterior tongue

glossopharyngeal

54

what is the cranial accessory nerve

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

55

how is visual acuity calculated

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