Neuroanatomy-overview of brainstem eye movements

Question 1

What 4 muscles does CN III innervate?

Answer 1

Superior rectus
Medial rectus
Inferior rectus
Inferior oblique

Question 2

What muscle does CN VI innervate

Answer 2

Lateral recuts

Question 3

What muscle does the Trochlear CN innervate

Answer 3

Superior oblique

Question 4

Answer 4

Question 5

Answer 5

Question 6

Communication between the CN 3,4 and 6 occurs via the ______ ________ ________ ________ to coordinate eye movements

Answer 6

Communication between the CN 3,4 and 6 occurs via the ascending medial longitudinal fasciculus to coordinate eye movements

Question 7

Where is the vertical gaze center located?

Where is the Horizontal gaze centre located?

Answer 7

vertical gaze- the Midbrain

Horizontal gaze- The Pons in the Paramedian pontine reticular formation (PPFR)

Question 8

What are Saccades

Answer 8

The most common type of eye movement - quick orientation in space, eyes move rapidly back and forth

Question 9

What is pursuit in the context of vision?

Answer 9

Keeping an object stable on the fovea

Pursuit Movement • Tracking an object • stabilize an image on the retina • cortical information • primary visual cortex “the object” • frontal eye fields “move eyes” • cerebellar information • “How am I moving in the environment?” • vestibular information • “Where am I in the environment?”

Question 10

What is the vestibulo-ocular refelx

Answer 10

Compensation of head movement - keeping the image stable

Question 11

What are Volitional Saccades?

Answer 11

Volunteer control over eye moemvent

Anti saccade

memory saccade and predictive saccade

Question 12

Anti-saccade

Answer 12

Looking away from a stimulus

Question 13

Memory saccade

Answer 13

Looking towards where a stimulus was (but no longer is)

Question 14

Predictive saccade

Answer 14

Looking towards where a stimulus will be (but isn’t yet)

Question 15

Reflexive Saccades

Question 16

Your patient has a horizontal gaze palsy, Where does this suggest. a lesion in the brain?

Answer 16

Lesion in the pons

Question 17

Your patient has a vertical gaze palsy, where in the brain do you expect a lesion?

Answer 17

Lesion int he mid brain

Question 18

What is disconjugate gaze, What are the two types

Answer 18

Eyes move in different directions

1) Convergence
2) divergence

Question 19

what is nystagmus

Answer 19

is an involuntary rhythmic side-to-side, up and down or circular motion of the eyes that occurs with a variety of conditions.

Question 20

What makes up the tectum

Answer 20

Superior and inferior colliculus, superior and inferior medullary velum

Question 21

Where do motor fibres travel in the brainstem?

Answer 21

The travel in the base of the brainstem

cerebral peduncles (crus cerebri)

Basal pons

pyramids

Question 22

What part of the brain stem are the nuclei of CN III and CN IV located in?

Answer 22

The midbrain

Question 23

What craninal nerves are in the pons?

Answer 23

CN V

CNVI

CNVII

CN VIII

Question 24

What CN are in the Medulla

Answer 24

CN IX

CN X

CN XII