Lecture 2 - Dipolpia

Question 1

what is the technique for examining extraocular muscles

Answer 1

instruct patient to…

• follow your finger with eyes, not head
• report if they see two objects at any time during the test
• finger 12-18” away from face
• move slowly in “H” pattern, noting any weakness or nystagmus

Question 2

what are the cardinal fields of Gaze or “H pattern” of Gaze

Answer 2

Question 3

what muscles of the eye are under CN III (oculomotor’s) control

Answer 3

medial rectus, superior rectus, inferior rectus, inferior oblique, and levator palpebrae superioris

Question 4

moves the eye medially (nasally) form the midline position

Answer 4

medial rectus

Question 5

moves the eye superiorly from the extreme lateral position

Answer 5

superior rectus

Question 6

moves the eye inferiorly from the extreme lateral position

Answer 6

inferior rectus

Question 7

moves the eye superiorly from the extreme medial (nasal) position

Answer 7

inferior oblique

Question 8

if upper lids do not elevate, result

Answer 8

levator palpebrae superioris lesion

Question 9

if the globes do not elevate, result

Answer 9

lesion with inferior oblique and superior rectus

Question 10

what eye muscle is under control of by CN IV (trochlear)

Answer 10

superior oblique muscle

Question 11

moves the eye inferior from the extreme medial (nasal) position

Answer 11

superior oblique muscle

Question 12

what is the position of the patients head to resolve their diplopia from a R weak superior oblique?

where is the eye on the weak side directed?

Answer 12

L head tilt (R sits higher)

superior medial

Question 13

do patients have double vision with CN III lesions?

Answer 13

no, only ptosis

Question 14

when a patients eye moves by itself, this is called

Answer 14

dissociated nystagmus

Question 15

when a patients eye’s jump together, this is called

Answer 15

nystagmus

Question 16

• when acetylcholine receptors are attacked with antibodies (usually gets worse with age)
• diplopia and ptosis is this until proven otherwise
• failure of elevation of globe and upper lid, confrims Dx of this
• evaluate neck extensors and look at repetitive bulbar muscle function
• pupillary light reflexes are normal

this is called

Answer 16

myesthenia gravis

Question 17

Answer 17

aneurysm, junction of internal carotid artery and anterior cerebral artery

CN III condition

Question 18

Answer 18

aneurysm of posterior communicating artery at junction of posterior cerebral artery

CN III condition

Question 19

Answer 19

1. CN III
2. chiasm
3. cavernous sinus
4. CN VI

Question 20

Answer 20

1. internal carotid artery
2. CN IV
3. V1
4. V2