Vestibular system Flashcards
What are the 3 primary functions of the vestibular system?
- postural stability
- gaze stability
- resolution of sensory conflict - visual / somatosensory conflict
Vestibular system detects forces created by _______ as we move.
gravity
Information that the vestibular system determines is used to generate _______ and ______ responses.
postural; visual
Vestibular disorders cause what 3 things?
- abnormal sense of movement
- visual instability
- loss of balance
Vestibular information must be integrated with _______ and ________ for postural control.
vision; somatosensation
Frequency of dizziness increases with ____.
age
Hair cell loss contributes to dizziness as we age (T/F).
T
___% of people 45+ complain of dizziness (women>men).
10
Neuronal loss in vestibular nuclei ___%/year from age 40.
3
What are 5 lesions associated with vestibular dysfunction?
- Vestibular end organ
- Vestibular nerve terminals
- Cerebellopontine
- Brainstem/cerebellum
- Vestibular projectins to cerebral cortex
Endolymph movement deflects ______ and activates _______.
cupula; ampulla
Together the ________ ______ make up a 3d representation of head motion.
semicircular canals
_______ detect acceleration/deceleration and gravitational pull.
otoliths
________ detects horizontal motion
utricle
______ detects sagittal plane motion
saccule
What are the 4 types of dizziness?
- vertigo
- imbalance
- disequilibrium
- lightheadedness
_________ = defined as a hallucination of motion of the body or the environment and may be rotary or linear
vertigo
_______ = impaired ability to maintain orientation of body in space
imbalance
_______ = feeling of drunkenness or dis-orientation
disequilibrium
_________ = cardiovascular or metabolic
lightheadedness
_______ is a cardinal symptom of vestibular system disease
vertigo
________ signifies chronic vestibular or neurologic disease
imbalance
________ can be vestibular, metabolic, and multisensory.
lightheadedness
Disruption of vestibular nerve firing on one side causing loss of ________ firing.
tonic
In __________ _______ the brain interprets the mismatch between the two sides of the brain as movement.
vestibular dysfunction
How long does compensation take for vestibular dysfunction?
~ 2 weeks
If the vestibular dysfunction is due to a stable lesion, the brain will compensate with ______.
vision
Vestibular system drives _____ movement.
eye
What are the 3 pathways that stabilize the body using info from vestibular system?
- Lateral vestibulospinal
- Medial vestibulospinal
- Reticulospinal
_______ vestibulospinal: info from cerebellum and otoliths
lateral
_______ vestibulospinal: info from semicircular canals
medial
_______ vestibulospinal: postural activity of lower extremities in response to head position changes with respect to gravity
lateral
_______ vestibulospinal: postural responses with regard to angular position changes
medial
__________ tract : info from vestibular nuclei, concerned with maintaining balance.
reticulospinal
Together the 3 vestibulospinal tracts provide ________ postural control.
automatic
What are 5 vestibular symptoms?
- change in heading
- dizziness
- vertigo
- light-headedness
- oscillopsia
What are 5 vestibular syndromes/diseases?
- continuous vertigo
- benign paroxysmal positional vertigo
- vestibular neuronitis
- meniere’s syndrome
- acoustic neuroma
________ syndrome = episodic vertigo
Meniere’s
_________ vertigo = acute, unilateral loss of vestibular function
continuous
What might cause continuous vertigo?
- temporal bone fracture
- labyrinthine concussion
- surgical labyrinthectomy
- infarction in the vestibular nucleus
______ gait may present with continuous vertigo.
ataxic
Most continuous vertigo episodes fully resolve in a few days via cessation of ______ discharge and _____ plasticity.
tonic; CNS
_____ ______ _____ vertigo = episodic intense vertigo
benign paroxysmal positional vertigo (BPPV)
BPPV = women: men; __:__
6:1
What is the most common cause of vertigo?
BPPV
BPPV = ____ attacks of vestibular vertigo lasting <1 min
five
BPPv = causing by increased fluid pressure in _______, density or clumping of ______.
labyrinths; otoliths
BPPV = onset after rapid ____ motion
head
What is the treatment for BPPV?
- habituation
2. canalith repositioning
Vestibular ________ = viral infection
neuronitis
What are 3 symptoms of of vestibular neuronitis?
- vertigo
- nystagmus
- nausea and vomiting
Vestibular neuronitis resolves within ___ weeks to ___ months.
6; 3
Meniere’s syndrome: over accumulation of ________.
endolymph
What are 4 symptoms of Meniere’s syndrome?
- episodic vertigo
- tinnitus
- fullness of ears
- hearing loss
Is Meniere’s syndrome more common in men or women?
women
What are 3 treatments for Meniere’s syndrome?
- Diuretics
- Histamine
- Corticosteroids
What is another name for an acoustic neuroma?
Vestibular schwannoma
Acoustic neuroma = intracranial tumor of myelin forming cells of CN ____.
VIII
What are 5 causes of central vestibular loss?
- Vascular events
- TBI
- Brain tumours
- MS
- Stroke