Vestibular Flashcards
provides sensory input about both angular and linear acceleration
orients the head with respect to gravity
membranous labrinth
peripheral sensory apparatus
somatosensory and visual cues
cerebellum
reticular formation, cortex
central processing system
generates compensatory eye movements for gaze stability
body movements for postural stability with locomotion
motor output system
contains 5 sensory organs 3 semicircular canals 2 otolith organs motion sensors (hair cells) endolymph
membranous labyrinth
information from the semicircular canals is used to
stabilize vision
normally as the head moves in one direction the eyes move in the opposite direction with equal velocity
regulated by the semicircular canals
VOR gain
responsible for maintaining gaze stability at >60 deg/sec
vestibular system
responsible for maintaining gaze stability at
smooth pursuit
differences between sides int he tonic firing rate within the vestibular nuclei
indicates that one vestibular system is more active than the other
nystagmus
nystagmus: fast beat is always towards the
more active/hyperactive side
systolic BP drops by at least 20 mmHg within 3 min of standing and patient is symptomatic
orthostatic hypotension
reaches a crescendo in 10 min associated with dizziness
panic attack
spells last 4-60 min with/without heatache
migranes
vertigo
peripheral
central
more common (with head movement) less common
nystagmus
peripheral
central
jerk (fast beat, slow beat)
vertical, pendular
balance
peripheral
central
not as affected
affected