Vestibular System Flashcards
What does the Doll’s eyes maneuver state?
in the unconscious patients, side-to-side movement of the head results in horizontal movement of the eyes in the opposite direction
if I turn my patients head to the right, what is a normal response?
horizontal gaze to the left
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?
left VI palsy
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?
a right III palsy
if i turn my patient’s head to the right and there is no response (neutral gaze) what does this indicate?
possible midbrain damage
oculocaloric testing for VOR states what about ice water?
ice water caloric testing causes the eyes to turn toward the stimulus and they show horizontal nystagmus to the opposite ear
oculocaloric testing for VOR states what about warm water?
warm water caloric testing normally causes the eyes to turn away from the stimulus with horizontal nystagmus toward the stimulated ear
What does absent VOR suggest?
ipsilateral vestibular impairment of the stimulated lateral semicircular duct
the medial longitudinal fasciculus is a white matter tract projected from the vestibular nuclei. what is this tract critical for?
it is a critical link in synchronized eye movements especially horizontal gaze
which tract coming from the vestibular nucleus is important for the head turning to the side of the stimulus?
the MVST
which tract coming from the vestibular nucleus is important for the body turning to the side of the nucleus?
the LVST
what is the significance of the reticular formation coming from the vestibular nucleus?
nausea, vertigo, visceral disturbances
vestibulo-ocular responses include what?
doll’s eyes maneuver and oculocaloric testing
what is a critical center for horizontal gaze and it is the staging and coordinating area of the oculomotor system?
PPRF
what are some signs and symptoms of lesions of the vestibular system?
nystagmus, vertigo, postural impairment
how is postural impairment tested?
using the Romberg test
when performing the romberg test, if the patient has a lesion, which side does he tend to fall toward?
toward the side of the lesion
a unilateral lesion of the MLF superior to the abducens nucleus results in what?
a contralateral disturbance of horizontal gaze (impairment of adduction of the ipsilateral eye and nystagmus of the abducting eye)
what is a unilateral lesion of the MLF referred to as?
an internuclear ophthalmoplegia
how is an INO always named?
according to the side of oculomotor impairment (the eye that does not adduct)
what specifically does not use the MLF and is unaffected by INO?
accommodation
a unilateral lesion of the PPRF results in what?
paresis or paralysis of horizontal gaze toward the same side of the lesion
the PPRF sends fibers where?
to the ipsilateral abducens nucleus and the contralateral occulomotor nucleus
