26: Vestibular System Flashcards
Purpose of the vestibular apparatus
Signal changes in motion and position of head with respect to gravity
What does the vestibular apparatus influence?
Postural and proximal limb muscle tone, oculomotor system
Two parts of the vestibulocerebellum
Flocculonodular node + fastigial nucleus
INO
Characteristic disturbance of horizontal gaze where one eye does not adduct
Is the lesion cause INO ipsilateral or contralateral?
Ipsilateral
Describe what the two eyes do during right INO and trying to look to the left
When trying to look left, the right eye does not adduct + the left eye exhibits nystagmus
Is accommodation affected by INO? Why?
No - it does not use the MLF pathway
Critical center for horizontal gaze + staging center for the oculomotor system
Parmedian pontine RF
Two places the parmedian pontine RF sends fibers to
Ipsilateral CN 6 + contralateral CN 3 nucleus
Lesion of the parmedian pontine RF
Paresis or paralysis of horizontal gaze towards same side of lesion + gaze preference away from lesion
Is pt conscious during Dolls eye maneuver test?
Unconscious
Contraindications to Dolls eye maneuver
Cervical injury
What system does the dolls eye maneuver test?
Vestibuloocular response using MLF pathway
What does the oculocaloric testing for vestibuloocular response assess?
CN 3, CN 6, their connections to the vestibular system
When performing the oculocaloric test on a conscious pt, what should pts eyes do with cold and warm water?
Cold water: nystagmus to opposite side
Warm water: nystagmus to the same side (COWS)
