Ocular Motor Control Flashcards

1
Q

The pathway that starts in the frontal eye fields, through the internal capsule to end in the paramedian pontine reticular formation controls _

A

Saccadic eye movements (Crosses midline)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The pathway that starts in the posterior parietal lobe to end on the ipsilateral paramedian pontine reticular formation controls _

A

Pursuit eye movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The goal of eye movements is to maintain objects focused on _, which has the highest concentration of _

A

Fovea

Cone receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In general, horizontal ey movements are controlled by the _ while vertical eye movements are controlled by _. What are the nuclei?

A

Pons (PPRF)

Midbrain (riMLF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Vergence movement (convergence and divergence) involves what muscles and what part of the brain?

A

Medial Rectus

Midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Occulovestibular eye movements serve to _

A

Move eyes in the opposite direction from head to maintain focus / gaze

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A type of eye movement that uses the same pathway as saccades but gets inputs from different structures is . Where does this input originat?

A

Occulo-vestibular movements

Semi-circular canals, VIII CN and VIII nucleus (crosses) to CN 3,4,6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

A second more complex vestibulo-occular pathway consists of _ (3)

A

Reticular formation, interstitial nucleus of Cajal and cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The MLF allows connections between _ (2 connections)

A

Nucleus of 6 to contralateral CN3

Nucleus of 8 to contralateral CN6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Vestibulo-occular pathway integrity can be tested with _

A

Doll’s head maneuver (oculocephalic manuever)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The saccdic eye generator is _

A

PPRF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A supra-nuclear disorder (e.g. frontal eye field damage) will a cause _

A

Loss of voluntary gaze

Reflex gaze intact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Another word for vestibulo-occular reflex is _

A

Occulo-cephalic reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the effect of internuclear opthalmoplegia?

A

Ipsilateral medial rectus paresis (Complete MR block)

Contralateral nystagmus with abduction (Partial LR block)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Dorsal midbrain syndrome (Parinaud’s syndrome) involves a lesion in _

A

Posterior commissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

4 symptoms of parinaud’s syndrome are _

A

Loss of upgaze
dissociation of pupillary light reflex
convergence-retraction convergence
lid retraction

17
Q

A lesion to nucleus of CN3 leads to _

A

Ipsilateral paresis of innervated muscles
Additionally, contralateral paresis of SR
Ptosis
Likely bilateral findings because lesion on midline

18
Q

A lesion to nucleus of CN4 leads to _

A

Contralateral SO paresis

19
Q

A lesion to nucleus of CN6 leads to _

A

Paresis of conjugate horizontal gaze to ipsilateral side (Blocks both LR and MR)

20
Q

CN3 lesion leads to _

A

Down and out
Ptosis
Dialated / unresponsive pupil

21
Q

A PCA aneurism can cause _

A

3rd nerve palsy

22
Q

CN4 lesion leads to _

A

Eye deviated up (hypertropia)

23
Q

CN6 lesion leads to _

A

Eye deviated in (esotropia)

24
Q

In patients with MLF syndrome, why is convergence normal?

A

Because the cortex directly innervates the CN3 (MR) nucleus for both eyes. MLF if bypassed