Dizzy Patient Flashcards
How is balance controlled?
Input
Integration & processing
Motor control
Where does balance receive input from?
Vestibular system Proprioception Vision Auditory Cerebellar/cerebral
Where does balance integration and processing occur?
Brainstem
What is the structure of the vestibular system?
3 canals on each side - paired
- L superior & R posterior
- L posterior & R superior
- L horizontal & R horizontal
Otolith organs
- saccule
- utricle
What is the vestibular system responsible for sensing?
Linear acceleration
Gravity
Angular acceleration
What senses linear acceleration?
Utricle
What senses gravity?
Saccule
What senses angular acceleration?
Lateral semi-circular canals
As you turn your head, the degree of difference of action potentials tells the difference of angles
What is proprioception?
Ability to establish a sense of position in space
How is vision used in balance?
Binocular vision - depth perception
Peripheral vision - turn head to see something
Smooth pursuit - fix + follow works better at lower frequency
How can peripheral vision eye movements be tested?
Saccades = rapid ballistic movements of eyes which abruptly change the point of fixation
What are signs of a vestibular problem?
Patient does not turn head
Use vision as a balance tool
- easily fatigued
- avoid crowded places
What is the vestibulo-ocular reflex?
Ability to remain focused on an object as head is turned away from it
What is the mechanism of the vestibulo-ocular reflex?
Head movement = accelerate -> constant velocity -> stop
Eyes stay fixed by acting in opposite direction
What is gain (in relation of vestibulo-ocular reflex)?
Difference between head movement and eye movement
