Vestibular Flashcards
Feeling that you are about to faint or “pass out“, do not feel as though you or your surroundings are moving
Lightheadedness
Feeling that you or your surroundings are moving when there is no actual movement, feel as though you are spinning, falling, etc.
Vertigo
What part of the vestibular system detects angular acceleration (any rotational movement)?
Semicircular canals
What part of the vestibular system detects linear acceleration and gravity
Otoliths
- Utricle = horizontal acceleration
- Saccule = vertical acceleration
- Have hair cells that project into gelatinous matrix that have embedded otoconia
What causes positional vertigo?
Crystals break free and float through semicircular canals
- can be caused by trauma, can be caused by certain head movements
fluid in inner ear
Endolymph
- as we the head moves in one direction, the fluid moves another
Reflex eye movement that stabilizes images during head movement; Produces eye movement in the direction opposite the head movement; Preserves the image in the center of visual field
Vestibulo-ocular reflex
- when moves to the right, eyes move to the left
Provide automatic control of the postural muscles in order to stabilize the body
Vestibulospinal reflex
What are the 3 sensory systems that contribute to balance?
- Vestibular
- Vision
- Somatosensory (proprioception)
What are the possible causes of vestibular dysfunction in the CNS?
- Stroke or TIA
- Multiple sclerosis
- Trauma (TBI)
- abnormally with oculomotor testing
What S and S will you see with central pathology?
- Abnormal smooth pursuit and saccadic eye movements
- Diplopia
- Altered conscious
- More severe ataxia than with a peripheral lesion
- Vertigo less intense than with a peripheral lesion and not suppressed by visual fixation
- Spontaneous vertical nystagmus
- Eyes oscillate at equal speeds
- Keys to point towards central: problems with vision, problems with confusion - if pt has 2-3 of these and its not dx yet, refer out to get dx, then we can help
How is PT incorporated with central lesions?
- Educate on safety precautions and fall prevention strategies
- Gait training
- Balance exercises
- Habituation exercises
What are the types of peripheral vestibular dysfunction?
- Mechanical (BPPV)
- Decreased receptor input (UVH, BVH)
- we have a firing rate in our inner ear, and on each side they should be the same; when firing is not the same on both sides, get hypofunction
Otoconia misplaced in semicircular canals; Vertigo provoked by changes in head position in relationship to gravity; Most commonly involves posterior canal
Benign paroxysmal positional vertigo (BPPV)
- Anterior, posterior, horizontal are 3 but posterior is 90% of cases
What is the Dix-Hallpike test
test for posterior canal BPPV
- 45* to side testing
- ~30* of ext
- tell pt to keep their eyes open
- latency – need to hold them in that position for a few seconds up to a min
- looking for nystagmus