Lect 6 diplopia

Question 1

Match the following EOM’s to their actions:

1) superior rectus
2) inferior rectus
3) superior oblique
4) inferior oblique
5) medial rectus
6) lateral rectus

a) ADduction
b) depression, extorsion, ADduction
c) extorsion, elevation, ABduction
d) intorsion, depression, ABduction
e) ABduction
f) elevation, intorsion, ADuction

Answer 1

1) superior rectus–f) elevation, intorsion, ADuction
2) inferior rectus–b) depression, extorsion, ADduction
3) superior oblique–d) intorsion, depression, ABduction
4) inferior oblique–c) extorsion, elevation, ABduction
5) medial rectus–a) ADduction
6) lateral rectus–e) ABduction

Question 2

(T/F) Sherrington’s law of reciprical innervation explains binocular coordination of eye movements (versions/saccades) and states that paired agonist muscles (yoked muscles) from each eye operating in the same field of action receive equal innervation

Answer 2

False (this is Herrings law of equal innervation)…Sherrington’s law states when a muscle contracts its direct antagonist will relax to an equal extent to allow for smooth movement

Question 3

(T/F) Ice water irrigation of the ears (cold caloric testing) directly tests VOR

Answer 3

true. C.O.W.S (cold opposite, warm same)

Question 4

Which structures are responsible for controlling vertical saccades?

a) riMLF and nucleus of Cajal (supernuclear control of vertical saccades located at top part of midbrain)
b) PPRF
c) CN VI nucleus
d) MLF

Answer 4

a) riMLF and nucleus of Cajal (supernuclear control of vertical saccades located at top part of midbrain)

Question 5

Which structures are responsible for controlling horizontal saccades?

a) interstitial nucleus and interstitial nucleus of Cajal (top part of midbrain)
b) PPRF
c) CN IV nucleus
d) MLF

Answer 5

b) PPRF (supernuclear control of horizontal saccades located in pons)

Question 6

(T/F) Comitant relates to the same amount of ocular misalignment in all directions of gaze indicating a congenital discrepancy, whereas, incomitant refers to different amounts of ocular misalignment in different directions of gaze indicating an acquired discrepancy.

Answer 6

true

Question 7

(T/F) Convergence spasm can mimic bilateral CN 6 palsy

Answer 7

true

Question 8

Which of the following is NOT a sign of convergence spasm?

a) pseudomyopia that cannot be resolved
b) variable esotropia that can be unilateral or alternating
c) limited ABduction
d) pupillary miosis
e) normal ABducting saccades
f) intact abduction with VOR and ductions

Answer 8

a) pseudomyopia that cannot be resolved (false, it can be resolved with cycloplegia)

Treatment for convergence spasm: cycloplegic refraction and reading/full time spectacles

Question 9

Name the two rare causes of monocular diplopia.

Answer 9

Palinopsia (a parietal lobe disease) and Cerebral polyopia (a cortical disease)

Question 10

Match the following:

1) horizontal diplopia
2) vertical diplopia
3) both

a) Convergence/divergence insufficiency
b) CN III palsy
c) CN IV palsy
d) CN VI palsy
e) INO
f) thyroid associated opthalmopathy
g) Myasthenia gravis
h) skew deviation

Answer 10

a) Convergence/divergence insufficiency–1) horizontal diplopia
b) CN III palsy–3) both
c) CN IV palsy–2) vertical diplopia
d) CN VI palsy–1) horizontal diplopia
e) INO–1) horizontal diplopia
f) thyroid associated opthalmopathy–3) both
g) Myasthenia gravis–3) both
h) skew deviation-2) vertical diplopia

Question 11

(T/F) If your pt cannot look towards their nose and downward the superior oblique is impacted

Answer 11

true

Question 12

Which of the following gaze palsies are causes of binocular diplopia?

a) internuclear opthalmoplegia (INO)
b) bilalteral INO (BINO)
c) Wall-eyed BINO (WE-BINO)
d) one and half syndrome (paralytic pontine exolytic-tropia)
e) skew deviation
f) all of the above

Answer 12

f) all of the above

Question 13

Know and understand Parks 3 step

Answer 13

….

Question 14

(T/F) With the red lens of the Maddox rod over the right eye, your pt sees a red line under the white light. This is indicative of a right hypertropia

Answer 14

true

Question 15

Where do the four recti muscles originate?

Answer 15

common tendinous ring

Question 16

T/F: vertical saccade defect is usually localized to midbrain while horizontal saccade defect are usually localized to cerebral cortex or pons

Answer 16

True

Question 17

T/F: defective pursuit may be due to a lesion in FEF, pontine nuclei, cerebellum

Answer 17

True

Question 18

Which one of the following is a supranuclear control of pursuits?

A) PPRF
B) Nucleus of Cajal
C) Frontal eye fields and supplementary eye fields
D) riMLF

Answer 18

C) Frontal eye fields and supplementary eye fields (smooth pursuit is independent of the PPRF)

Question 19

What four conditions can result in a decompensated phoria?

Answer 19

CI, DI, CE, DE

Question 20

What three cranial nerve palsies can cause diplopia?

Answer 20

3, 4, 6

Question 21

Which one of the following is not a possible cause of diplopia?

A) CN palsy
B) Decompensated phoria
C) Gaze palsy
D) Myasthenia Gravis
E) Orbital disease (orbital tumor/thyroid eye disease)
F) All of the above can cause diplopia

Answer 21

F) All of the above can cause diplopia

Question 22

Which one of the following is not one of the four diplopia questions?

A) Does the double vision go away when one eye is covered?
B) Is the double vision horizontal or vertical?
C) Is the double vision greater at distant or near?
D) Is the double vision greater in the right or left gaze?
E) All of the above are questions for diplopia

Answer 22

E) All of the above are questions for diplopia

Question 23

What is the purpose of asking if the double vision is greater at distance or near?

Answer 23

If diplopia is greater at distance, it would affect your lateral rectus. If it is greater at near, it would affect your medial rectus

Question 24

What is the most common cause of monocular diplopia?

Answer 24

Optical aberration rarely due to cortical disease (pinhole occlusion will eliminate monocular diplopia)

Question 25

A CN 3, 4, or 6 palsy would NOT be which two of the following:

a) nuclear lesion
b) infranuclear lesion
c) supranuclear lesion
d) internuclear lesion

Answer 25

c) supranuclear lesion

d) internuclear lesion

Question 26

Name five internuclear gaze palsies

Answer 26

INO, BINO, WebINO, one and half syndrome, skew deviation