Vestibular System

Question 1

What does the Doll’s eyes maneuver state?

Answer 1

in the unconscious patients, side-to-side movement of the head results in horizontal movement of the eyes in the opposite direction

Question 2

if I turn my patients head to the right, what is a normal response?

Answer 2

horizontal gaze to the left

Question 3

if i turn my patient’s head to the right and their right eye adducts and their left eye is neutral, what does this indicate?

Answer 3

left VI palsy

Question 4

if i turn my patient’s head to the right and their left eye abducts and their right eye is neutral, what does this indicate?

Answer 4

a right III palsy

Question 5

if i turn my patient’s head to the right and there is no response (neutral gaze) what does this indicate?

Answer 5

possible midbrain damage

Question 6

oculocaloric testing for VOR states what about ice water?

Answer 6

ice water caloric testing causes the eyes to turn toward the stimulus and they show horizontal nystagmus to the opposite ear

Question 7

oculocaloric testing for VOR states what about warm water?

Answer 7

warm water caloric testing normally causes the eyes to turn away from the stimulus with horizontal nystagmus toward the stimulated ear

Question 8

What does absent VOR suggest?

Answer 8

ipsilateral vestibular impairment of the stimulated lateral semicircular duct

Question 9

the medial longitudinal fasciculus is a white matter tract projected from the vestibular nuclei. what is this tract critical for?

Answer 9

it is a critical link in synchronized eye movements especially horizontal gaze

Question 10

which tract coming from the vestibular nucleus is important for the head turning to the side of the stimulus?

Answer 10

the MVST

Question 11

which tract coming from the vestibular nucleus is important for the body turning to the side of the nucleus?

Answer 11

the LVST

Question 12

what is the significance of the reticular formation coming from the vestibular nucleus?

Answer 12

nausea, vertigo, visceral disturbances

Question 13

vestibulo-ocular responses include what?

Answer 13

doll’s eyes maneuver and oculocaloric testing

Question 14

what is a critical center for horizontal gaze and it is the staging and coordinating area of the oculomotor system?

Answer 14

PPRF

Question 15

what are some signs and symptoms of lesions of the vestibular system?

Answer 15

nystagmus, vertigo, postural impairment

Question 16

how is postural impairment tested?

Answer 16

using the Romberg test

Question 17

when performing the romberg test, if the patient has a lesion, which side does he tend to fall toward?

Answer 17

toward the side of the lesion

Question 18

a unilateral lesion of the MLF superior to the abducens nucleus results in what?

Answer 18

a contralateral disturbance of horizontal gaze (impairment of adduction of the ipsilateral eye and nystagmus of the abducting eye)

Question 19

what is a unilateral lesion of the MLF referred to as?

Answer 19

an internuclear ophthalmoplegia

Question 20

how is an INO always named?

Answer 20

according to the side of oculomotor impairment (the eye that does not adduct)

Question 21

what specifically does not use the MLF and is unaffected by INO?

Answer 21

accommodation

Question 22

a unilateral lesion of the PPRF results in what?

Answer 22

paresis or paralysis of horizontal gaze toward the same side of the lesion

Question 23

the PPRF sends fibers where?

Answer 23

to the ipsilateral abducens nucleus and the contralateral occulomotor nucleus