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Flashcards in cranial nerves 12/27 Deck (51)
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1
Q

smell

A

CN 1
* close eyes, plug one nostril, smell olfactory stimulus placed under open nostril
+ inability to smell could indicate CN lesion, mucus, extreme old age, smoking history
Skip if deficit is not suspected

2
Q

optic

A

CN 2

  • Patient covers left eye and looks into examiners eye
  • Ask patient to identify when examiner’s finger moves. Position finger approximately 2 feet lateral two and 6 inches above right eye, then flex finger. Repeat with finger position laterally and below, medially and above, and medially and below. Then test opposite eye.
3
Q

Pupillary Light Reflex

A

CN 2,3

  • Have patient look at distant object over examine her shoulder to prevent pupillary response to looking at a near object.
  • Rapidly move flashlight to shine in one eye and then away. Normally both eyes will constrict equally.
  • Repeat with opposite eye.
4
Q

Upper eyelid position and raising upper eyelid

A

CN3, levator palpebrae
Ask patient to look straight ahead and observe space between upper back/lower eyelids (should be symmetrical). Ask patient to look up forward without moving head - upper eyelid should retract with upward gaze

5
Q

Pupillary Responses

A

CN 2, 3
Observe pupils in room light - should be symmetric. CN3 lesion interferes with ipsilateral pupil, causing dilated pupil due to unopposed sympathetic input.
* Response to light
* Response to near\far- ask patient to look at distant object and then examiners nose. Pupil should dilate when looking at far object, constrict one looking at near object. CN III lesion will cause pupil to be dilated and remain unchanged.

6
Q

Convergence

A

CN 3
Ask patient to look at tip of pen as it is slowly moved from approximately 2 feet away toward patient’s nose. Both eyes should remain directed until pen is within 10 cm of nose

7
Q

Gaze Stability and Extraocular movements

A

CN 3, 4, 6
a. Forward gaze - both eyes should appear to look in the same direction, no nystagmus
Inspect eyes for asymmetry or ptosis
* Ipsilateral CN III lesion – one eye laterally and down
* Ipsilateral CN IV lesion – one eye looks upward
* Ipsilateral CN VI lesion – one eye looks medially
* Diplopia – present with any of the above

8
Q

Ipsilateral CN III lesion

A

normal gaze - one eye laterally and down

w/wo diplopia

9
Q

Ipsilateral CN IV lesion

A

normal gaze - one eye looks upward; Unable to depress eyes

w/wo diplopia

10
Q

Ipsilateral CN VI lesion

A

normal gaze - one eye looks medially;
Unable to abduct eyes
w/wo diplopia

11
Q

eye alignment

A

CN 3,4,6
ask patient look at distant object in central vision
* Cover Test (for trophia) – Cover left eye, and if right eye remains directed at target response is normal. If right eye moves, right eye is tropic. Repeat with opposite eye.
* Cover/Uncover test (for phoria) – cover one eye ~10seconds, then quickly uncover. Observe eye for any movement at instant eye is uncovered. Normal response is no movement. Movement indicates eye is phoric

12
Q

smooth pursuit

A

CN 3,4,6

patient’s eyes follows examiners finger in H pattern

13
Q

voluntary saccades

A

CN 3,4,6
hold index fingers ask to look back and forth between fingers
look at vertically striped cloth, move cloth horizontally

14
Q

dynamic visual acuity

A

CN 3,4,6
maintain gaze on and read eye chart/image held stable 12-18 inches from the face as examiner/patient rotates patient’s head at 2Hz
requires intact VOR

15
Q

nystagmus

A

CN 3,4,6

physiologic, pathologic, eye closed, eccentric gaze holding, BPPV

16
Q

light touch/pin prick face

A

CN 5

close eyes, identify sharp or dull stimulus on face

17
Q

corneal reflex

A
afferent CN5 (sensory), efferent CN7 (blink)
touch cotton swab to cornea of eye
18
Q

jaw clench

A

CN 5

patient clench jar, examiner push down on chin to try to separate

19
Q

mandibular movement

A

CN 5

protrusion, retrusion, lateral deviation

20
Q

facial expressions

A

CN 7

Raise eyebrows, close eyes tight, smile and show teeth, whistle and puff out cheeks

21
Q

tongue taste

A

Sweet vs salty, bitter
CN7 facial - anterior tongue
CN9 glossopharyngeal - posterior 1/3
CN 10 vagus - back part of mouth

22
Q

finger rub, watch ticking

A

CN 8

  • lightly rub fingertips near both ears, should hear equally; if not progress to tuning fork tests
  • hold watch far from ear and bring closer, record when first hears sound; + if unable to hear 18-24 inches or significant difference between sides
23
Q

rinne test

A

CN 8

  1. hold vibrating 512 Hz tuning fork on mastoid process until no longer hears it
  2. move ~1cm in front of ear canal, should be able to hear it again
    * sensorineural hearing loss, cochlear branch lesion - hears tuning fork through air after bone but reduced volume ipsilaterally
    * conductive hearing loss - unable to hear outside of canal bc blockage in auditory canal or middle ear lesion
24
Q

weber test

A

CN 8

  1. hold stem or tuning fork on top of head ask if sound is louder in one ear; should be same
    * sensorineural, cochlear branch lesion - louder in unaffected ear, neural function impaired in affected ear
25
Q

head impulse test

A

CN 8 VOR
look at examiners nose, head flexed 30deg
turn head passively and rapidly 2-3Hz small amplitude, abruptly stop in midline and observe eyes
- look for nystagmus or eye lag

26
Q

gag reflex

A

CN 9, 10
touch soft palate w cotton swab or tongue depressor to elicit gag reflex
* normal: gag, symmetric elevation of palate
* abnormal: absent, asymmetric elevation- uvula deviates to stronger unaffected side

27
Q

say “ahh”

A

CN 10

abnormal: voice hoarse, asymmetric elevation of soft palate - uvula deviates to stronger unaffected side

28
Q

resisted shoulder shrug

A

CN 10, SCM and trap strength

  • precaution for back or neck pain
  • abnormal: unilateral paralysis or paresis
29
Q

tongue protrusion

A

CN 12
tongue should protrude midline
* abnormal: deviates to weak side/side of lesion with ipsilateral atrophy

30
Q

bell’s palsy indicates damage to what CN?

A

CN 7

drooping eyelid, inability to lift eyelid, dryness of eye

31
Q

which CN provides autonomic innervation of abdominal viscera?

A

CN 10

32
Q

anosmia is related to damage to which CN?

A

CN1, unable to detect smells

33
Q

which CN originate in midbrain?

A

CN 3, 4

34
Q

which CN originate in pons?

A

CN 5-8

35
Q

which CN originate in medulla?

A

CN 9-12

36
Q

what CN originates in frontal lobe?

A

CN 1, olfactory bulbs both sides of crista galli

37
Q

what CN originates in temporal lobe?

A

CN 2 lateral colliculus

38
Q

ability to swallow

A

CN 9, 10

39
Q

what CN provides autonomic innervation to lacrimal glands?

A

CN 7

40
Q

what CN provides autonomic innervation to submandibular and sublingual glands?

A

CN 7

2nd and 3rd largest salivary glands

41
Q

what CN provides autonomic innervation to parotid gland?

A

CN 9

largest salivary gland

42
Q

what CN is involved with voluntary mastication?

A

CN 5

43
Q

what is the normal expected ratio of bone conduction to air conduction in Rinne test?

A

1:2 bone conduction vs air conduction

44
Q

branches of trigeminal nerve CN5

A

ophthalmic, maxillary, and mandibular

exits at pons

45
Q

how do you use a snellen chart

A

CN 2, patient stands 20 feet from the chart and proceeds to read the letters on the chart. The patient’s score is reported as 20 over the size of type the patient can read comfortably (e.g., 20/40).

46
Q

which CN is involved with chewing

A

CN5

47
Q

which CN is involved in sensation of anterior tongue

A

CN5

48
Q

which CN is involved in taste of anterior tongue

A

CN7

49
Q

which CN involved in swallowing

A

CN 9 and 10

50
Q

bells palsy typically due to

A

inflammation, CN7 compressed

treat with corticosteroids, train muscles to strengthen

51
Q

trigeminalgia

A

CN5 compressed, demyelinating

face hurts