41b - Oculomotor Disorders

Question 1

What is the difference between comitant and non-comitant strabismus?

Answer 1

Comitant = non-paralytic. visual axes misaligned in childhood. Angle deviation similar in all fields of gaze. No diploplia because of amblyopia (shutting off one eye). No specific muscle weakness.

non-comitant = paralytic. Presence of variable angles of deviation in different fields of gaze. Diplopia. Adults. Usually due to one or more EOM.

Question 2

What is strabismus?

Answer 2

misalignment of visual axes

Question 3

What is tropia? esotropia, exotropia, hyper?

Answer 3

visible eviation of eye.
ESOtropia = inward (crossed eyes)
EXOtropia = outward
Hypertropia = upward
Hypo = down

Question 4

What does phoria mean?

Answer 4

deviation only when fusion is disrupted (such as covering an eye)

Question 5

If the uncovered eye moves inward after an alternate cover test, which way was it turned?

Answer 5

if it moves inward, it started turned outward.

Question 6

If light reflex test shows conreal light relfex pointed laterally, which way is the eye turned?

Answer 6

lateral light reflex means esotropia (eye turned the opposite way = inward)

Question 7

(What is duction?

Answer 7

movement of only one eye.

Ex: ABduction

Question 8

What does version mean?

Answer 8

movement of both eyes.

EX: dextroversion = right gaze

Question 9

What does vergence mean?

Answer 9

movement of both eyes in opposite directions

ex: convergence

Question 10

What EOM perform intorsion?

Answer 10

superior rectus and superior oblique

Question 11

What EOM perform extorsion?

Answer 11

inferior rectus and inferior oblique

Question 12

do Recti (superior or inferior rectus) aBduct or aDduct?

Answer 12

rectus muscles aDduct.

obliques aBduct

Question 13

do inferior muscles intort or extort?

Answer 13

inferior muscles (oblique and rectus) extort
Superior muscles intort

Question 14

What is it called when the eyes shake back and forth with equal amplitude to and fro?

Answer 14

pendular nystagmus

Question 15

Which direction should a patient look to make their nystagmus worse?

Answer 15

in the direction of action of the weak muscle.

Question 16

Patient has ptosis, non reactive pupil and eye is down and out? diagnosis?

Answer 16

CN III palsy.

comomnly caused by berry aneurysms, tumors, etc.

Question 17

CNIII palsy and a headache is diagnosed as what?

Answer 17

aneurysm until proven otherwise.

Question 18

Patient has loss of aBduction and ESOtropia. Diagnosis?

Answer 18

CN 6 palsy. Lateral rectus is out.

Question 19

Patient complains of vertical diplopia and has head tilted to the right. Where is the lesion?

Answer 19

CN IV (trochlear) lesion. Patient tilts head toward side OPPOSITE weak muscle so left CN4 lesion.

Question 20

How can you worsen diplopia in a patient with CN 4 palsy?

Answer 20

force tilt their head towards the lesion.