Lect 6 diplopia Flashcards
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
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
(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
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
(T/F) Ice water irrigation of the ears (cold caloric testing) directly tests VOR
true. C.O.W.S (cold opposite, warm same)
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
a) riMLF and nucleus of Cajal (supernuclear control of vertical saccades located at top part of midbrain)
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
b) PPRF (supernuclear control of horizontal saccades located in pons)
(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.
true
(T/F) Convergence spasm can mimic bilateral CN 6 palsy
true
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
a) pseudomyopia that cannot be resolved (false, it can be resolved with cycloplegia)
Treatment for convergence spasm: cycloplegic refraction and reading/full time spectacles
Name the two rare causes of monocular diplopia.
Palinopsia (a parietal lobe disease) and Cerebral polyopia (a cortical disease)
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
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
(T/F) If your pt cannot look towards their nose and downward the superior oblique is impacted
true
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
f) all of the above
Know and understand Parks 3 step
….
(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
true
Where do the four recti muscles originate?
common tendinous ring
T/F: vertical saccade defect is usually localized to midbrain while horizontal saccade defect are usually localized to cerebral cortex or pons
True
T/F: defective pursuit may be due to a lesion in FEF, pontine nuclei, cerebellum
True
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
C) Frontal eye fields and supplementary eye fields (smooth pursuit is independent of the PPRF)
What four conditions can result in a decompensated phoria?
CI, DI, CE, DE
What three cranial nerve palsies can cause diplopia?
3, 4, 6
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
F) All of the above can cause diplopia
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
E) All of the above are questions for diplopia
What is the purpose of asking if the double vision is greater at distance or near?
If diplopia is greater at distance, it would affect your lateral rectus. If it is greater at near, it would affect your medial rectus
What is the most common cause of monocular diplopia?
Optical aberration rarely due to cortical disease (pinhole occlusion will eliminate monocular diplopia)
