McWhorter - Visual Motor

Question 1

double vision - diplopia

Answer 1

both fovea cannot focus on the same object in the visual field

Question 2

oculomotor damage

Answer 2

• ophthalmoplegia with eye turned down and out
• ptosis
• mydriasis; loss of lens accommodation

Question 3

trochlear damage

Answer 3

• diplopia
• extorsion of eye
• weakness in depression of adducted eye

Question 4

abducens damage

Answer 4

• diplopia
• medial deviation
• abductor paralysis

Question 5

vergence movements

Answer 5

eyes shift b/w distant and near object

• shift to near objects –> converge
• shift to far objects –> diverge

Question 6

conjugate movements

Answer 6

eyes move in same direction

1. saccadic = rapid from one target to another
2. smooth pursuit = keep image fixed on retina when moving
3. optokinetic = nystagmus - eyes reset to new target
4. vestibulo-ocular reflex = object fixed on retina with during brief movements of head

Question 7

paramedian pontine reticular formation (PPRF)

Answer 7

chief brainstem gaze center for horizontal gaze

Question 8

horizontal gaze center in PPRF

Answer 8

• PPRF originates left frontal eye field in cerebral cortex –> decussate in midbrain to synapse on right abducens nucleus –> right abducens goes to right lateral rectus
• also synapse with nerve on left side to terminate at left oculomotor nucleus –> innervate left medial rectus

Question 9

rostral interstitial nucleus of MLF (RINMLF)

Answer 9

located in midbrain - center for vertical gaze