Diplopia

Question 1

what are some signs of EOM dysfunction when its closer to the orbit

Answer 1

1. proptosis
2. congestion
3. maybe optic nerve swelling/pallor

Question 2

where do superior, inferior, medial, and recti muscles originate from

Answer 2

annulus of zinn

Question 3

what are the tertiary actions of the oblique muscles

Answer 3

abduction

Question 4

what are the tertiary actions of the recti muscles

Answer 4

adduction

Question 5

_____ law of innervation explains binocular coordination of eye movements. Paired agonist muscles from each eye operating in the same field of action receive equal innervation

Answer 5

herings

Question 6

____ law of reciprocal innervation is when a muscle contracts, its direct antagonist will relax to an equal extent to allow for smooth movement

Answer 6

sherrington’s

Question 7

explain what happens in convergence retraction nystagmus in parinaud’s syndrome

Answer 7

pt is trying to look up, but there is anamalous firing to the MR and they get nystagmus

Question 8

What types of eye movements are your EOMS involved in

Answer 8

1. saccades
2. pursuits
3. VOR
4. OKN

Question 9

In ______ lesions, the 3rd nucleus and fascicle and nerve are still intact, which means VOR and OKN will still be functioning.

Answer 9

supranuclear; in cortex –> directs actions of the ocular motor nerves

Question 10

Describe the pathway of vertical saccades

Answer 10

FEF sends projection to Superior Colliculus –> rIMLF and interstitial nucleus of Cajal which are in midbrain–> vertical saccades

Question 11

which CN’s are in charge of vertical eye movements

Answer 11

3 and 4

Question 12

where are horizontal saccades done? whats the pathway?

Answer 12

pons

FEF –>PPRF excites CN 6 nucleus –> signal to contralateral CN 3 via MLF

Question 13

T/F PPRF is responsible for generating saccades, not pursuits

Answer 13

true

Question 14

Describe pursuits pathway

Answer 14

FEF –> pontine nuclei –> contralateral cerebellum

Question 15

defective pursuits may be a lesion in what parts of the brain>

Answer 15

1. FEF
2. pontine nuclei
3. cerebellum

Question 16

which lesions will ALWAYS have impaired VOR and OKN

Answer 16

1. nuclear
2. fascicular
3. peripheral nerve

Question 17

diplopia occurs due to ______ phoria, or acquired EOM limitation, due to a nerve palsy or a restrictive defect, gaze palsies, NMJ problems, or orbital disease

Answer 17

decompensated (CI, DI, CE, DE)

Question 18

what are some characteristics of diplopia due to a decompensated phoria

Answer 18

1. intermittent diplopia
2. horizontal diplopia
3. no neurologic symptoms
4. full range of EOM’s
5. deviation is comitant
6. decreased horizontal fusional ranges
7. may have intermittent tropia

Question 19

_____ convergence spasm is usually due to intermittent diplopia, blurred vision at distance due to spasm of accommodation, more prevalent in young women, and can mimic bilateral CN _____ palsy. This is due to a spasm of the near reflex.

Answer 19

primary; 6

Question 20

what are signs of convergence spasm

Answer 20

1. pseudo myopia that resolves with cycloplegia
2. variable esotropia
3. limited abduction
4. pupillary miosis
5. NORMAL abducting saccades
6. Intact abduction with VOR and normal DUCTIONS

Question 21

What are the four diplopia questions to ask

Answer 21

1. Does the double vision go away when either eye is covered
2. Is the double vision horizontal or vertical?
3. Is the double vision greater at distance or near?
4. Is the double vision greater in the left or right gaze?

Question 22

what are common causes of monocular diplopia

Answer 22

1. uncorrected RE
2. corneal irregularity/scarring
3. lens change/subluxation
4. tear film abnormality
5. polycoria
6. maculopathy

Question 23

horizontal diplopia can be caused by:

Answer 23

1. CI
2. DI
3. III palsy
4. VI palsy
5. INO
6. MG
7. Thyroid associated problems

Question 24

vertical diplopia can be caused by:

Answer 24

1. III palsy
2. IV palsy
3. Thyroid associated problems
4. MG
5. Skew deviation (in midbrain)

Question 25

if double vision is worse at distance which muscles are we concerned about

Answer 25

1. divergers 2. elevators * opposite if double vision is worse at near

Question 26

What are signs of ocular misalignment

Answer 26

1. face turn (Dwaynes) 2. Head tilt - in 4th nerve palsy, in direction opposite of palsy 3. eye closure 4. depressed/elevated chin

Question 27

when will people not report diplopia even if there is ocular misalignment

Answer 27

1. high RE (amblyopia develops 2. cataract 3. optic nerve/retinal disease ( no vision in that eye) 4. longstanding childhood strabismus 5. ptosis

Question 28

What are causes of Internuclear lesions in binocular diplopia

Answer 28

- Gaze palsies - INO - BINO - WEBINO - One and half syndrome - Skew deviation

Question 29

T/F in intERnuclear lesions you still have VOR

Answer 29

true

Question 30

T/F, an isolated 6th nerve palsy occurs from a nuclear lesion

Answer 30

False; close association with PPRF --> will always result in a gaze palsy

Question 31

where do nuclear lesions occur

Answer 31

in brainstem; cranial nerves 3, and 4

Question 32

where do infra nuclear lesions occur

Answer 32

1. CN III 2. CN IV 3. CN VI 4. NMJ 5. mechanical EOM restriction due to orbital disease

Question 33

what do you look for while your evaluating your pt that complains of diplopia

Answer 33

1. misalignment, ptosis, pupillary abnormality 2. evaluate ductions 3. evaluate versions 4. evaluate vergence 5. evaluate pursuits and saccades 6. evaluate VOR 7. assess direction and amount of ocular misalignment 8. look for head tilt/turn/chin position 9. orbital signs (proptosis) 10. perform forced auction when indicated

Question 34

Isolate paretic muscle in horizontal diplopia by:

Answer 34

maddox rod 1. crossed diplopia: red line is to the left; medial rectus isn't working 2. uncrossed diplopia: red line is to the right; lateral rectus isn't working

Question 35

How do you know which eye the deviation is when performing the maddox rod test

Answer 35

look at which gaze the deviation is worse

Question 36

While performing maddox rod test, on left gaze, the eso deviation is even worse. what does this mean

Answer 36

the left LR is affected

Question 37

in _______, the eye sees the lower image

Answer 37

hypertropia

Question 38

what test do we do if only 1 muscle is involved

Answer 38

parks 3 step

Question 39

what are the steps in parks 3

Answer 39

1. identify the hypertrophic eye in primary gaze 2. determine if hypertropia increases in right/left gaze 3. determine if hypertropia increases on right or left head tilt

Question 40

what are limitation to parks 3 step

Answer 40

1. multiple muscles involved 2. doesn't work in cases of mechanical restriction of eye muscles 3. patient is sitting or standing

Question 41

what does the double maddox rod test determine

Answer 41

presence and quality of cyclodeviation