part 12

Question 1

ductions

Answer 1

one eye motion

Question 2

direction of ductions

Answer 2

abduction- moves away from
adduction- moves towards
elevation, depression
intorsion, extorsion

Question 3

vergence

Answer 3

disconjunctive eye movements
eyes move in opposite direction called vergence when normal

Question 4

convergence

Answer 4

both eyes look at nose

Question 5

divergence

Answer 5

both eyes look away from nose

Question 6

what plane has no vergence

Answer 6

vertical

Question 7

names for when eyes are rotating (vergence)

Answer 7

incyclovergence
excyclovergence

Question 8

Version circuits

Answer 8

conjugate eye movements (2 eyes move in same dirrection)

Question 9

herings law of equal innervation

Answer 9

due to innate connections in which the eye muscles responsible for eye movement are equally innervated

Question 10

what is connection behind version circuits

Answer 10

abducens nuclues and intersitital nuclei

Question 11

horizontal plane version circuits

Answer 11

dextral or leveversion

Question 12

vertical plane of version circuits

Answer 12

elevate or depress

Question 13

version/tilt procedure

Answer 13

hold patient head and have them tilt head to side up and down, L and R
- look for nystagmus and note direction
- nonsychrnonic eye movement
lack of counter tilt

Question 14

ocular alignment

Answer 14

test of skew
how do eyes hold gaze when covered and uncovered (switching between eyes)
look for vertical corrective movement of eyes as uncovered
interpret as vertical misalignment of eyes (central)

Question 15

Tropia

Answer 15

deviation of visual axes during binocular observation of target Cover uncover test (one eye) when eye covered does the uncovered eye move towards nose (isotropia)

Question 16

phoria

Answer 16

deviation of visual axes during monocular observation of target
- when eye is covered it deviates externally
- when uncovered moves back internally

Question 17

hypo/hyperphoria

Answer 17

is a skew and a sign of abnormal central pathology

Question 18

where is the ocular tilt reaction imballance coming from

Answer 18

in otolithic pathways anywhere from vestibular organs to midbrain

Question 19

ocular tilt reaction triad

Answer 19

1. skew deviation- vertical misalignment of eyes
2. head tilt toward trophic eye
3. ocular torsion- top of both eyes rotated towards lower ear
   - if all 3 present ocular tilt reaction complete, some partial forms exist

Question 20

ocular tilt reaction causes

Answer 20

brainstem or unilateral peripheral vestibular lesion
- site of head tilt is site of lesion

Question 21

abnormality- internuclear opthalamoplegia

Answer 21

gaze in unilateral MLF inactivation

Question 22

internuclear opthalamoplegia- unliateral

Answer 22

MLF site of lesion= site with adduction slow
eye that moves slow towards the nose on same side with lesion

Question 23

internuclear opthalamoplegia- bilateral

Answer 23

MLF site of lesion=site with adduction slow
both eyes not fully adducting, both show nystagmus and slow adduction

Question 24

vergence circuits purpose

Answer 24

disconguate eye movements
- align fovea of each eye with targets at different distances from observer through saccades
integrated at level of superior colliculus and lateral geniculate nucleus

Question 25

vergence circuit procedure

Answer 25

have patient look at fingers 2m from nose, focus on finger that is up (quick 1 up 1 down)
dynamic if fingers move
Look for convergence and divergence of eyes, conjugate eye movement and pupillary constriction
abnormalities are central problem

Question 26

neural integrator

Answer 26

gaze holding
ability to maintain fixation once visual target acquired
abnormality- leaky integrator

Question 27

leaky integrator

Answer 27

not maintain eyes on target once acquired OR eyes get to target but slip away then a corrective saccade brings back on target