Vestibular Rehab Flashcards
Purposes of Peripheral Vestibular System
Stabilize visual images on the fovea of the retina during head movement
Maintain postural stability
Provide information used for spatial orientation
What are the SCC primarily involved in?
Gaze stabilization
What are the otolith organs?
Saccule & Utricle
What do the otolith organs respond to?
Linear acceleration and gravity, assist with postural stability
What flows freely within the SCC and why?
Endolymph. Moves the otoconia in the cupula (sensory receptors)
What is the tonic firing rate?
80 pulses per second
Whats the relationship of the tonic firing rate?
For each degree/sec change in head velocity there is a 1 pulse/sec change in firing rate.
What is VOR?
Vestibulo-ocular reflex. Maintains gaze stability during rapid head movements.
What velocity does VOR operate up to?
400 deg/sec (60-400)
What maintains gaze stability when head is moving at less than 60 deg/sec?
Smooth pursuit.
What is the push-pull mechanism?
SCC’s work in pairs. Right ant/left post, right post/left ant, right and left horizontal.
How does the push pull mechanism work?
As head is turned to the RIGHT, the R horizontal SCC is depolarized = increased firing rate, and L is hyperpolarized = decreased firing rate.
What is the inhibitory cut off?
Hyperpolarization can only go to 0 not to neg numbers.
What might people with vestibular problems have a history of?
Dizziness, vertigo, lightheaded, disequilibrium, oscillopsia
How do you measure symptoms?
VAS, Dizziness Handicap Inventory (DHI), Functional disability scale, Motion sensitivity quotient.
FReq/duration of episodes, circumstances of provocation.
How is the direction of nystagmus named?
By the FAST eye movement.
When is nystagmus suppressed?
In the light and when pt is fixated on target.
What is pendular nystagmus?
No fast or slow phase. Caused by CNS lesion. Usually cerebellum..