Vestibular System Flashcards
Two systems involved in vestibular system
Peripheral vestibular system
Central vestibular system
Where are the receptors of the peripheral vestibular system located?
Receptors located in the inner ear, connected to the auditory organ (i.e., cochlea)
T/F: The central peripheral vestibular system responds to inner ear stimulation, angular acceleration of the head, gravity, and possibly vibration
False. The peripheral vestibular system responds to inner ear stimulation, angular acceleration of the head, gravity, and possibly vibration
T/F: If a vibrator is put on a muscle belly, more vestibular input will be present than if a vibrator is put on a bony structure
False. If a vibrator is put on a muscle belly, going to be mostly prop. Closer you are to bony structure, the closer it is to vestibular input.
T/F: Vibrations are detected by the proprioceptive system
False. Vibrations are detected by the vestibular system, closer to bony structures
T/F: If you stand on something that is vibrating and your whole body is moving, you are using prop. But if you are only vibrating a little and your head isn’t moving, you are using both prop and vestib.
False. You are using both prop and vestib when your whole body, including your head, is moving
The vestibular system that is a multimodal system: works intimately with visual and prop systems; close linkages with cerebellum, reticular system, and autonomic nervous system
Central vestibular system
System that has close links with cerebellum, reticular system, and autonomic nervous system
Central vestibular system.
System that explains why you want to throw up when on a boat/car
Want to throw up when on boat/car b/c vestibular info you are getting, which is close to the ANS and cerebellar system
T/F: specific functions of the central vestibular system can be broken up into multiple levels
False. Specific functions of the central vestibular system cannot be completely isolated. Must make sure you’re treating the vestib, not cerebellar system
All of the following EXCEPT which are functions of the vestibular system?
A. Awareness of head and body position relative to gravity
B. Antigravity muscle tone
C. Social-emotional regulation
D. Posture and equilibrium
E. Stable visual field
F. Physical and emotional security
C. Social-emotional regulation
T/F: Postural control problems are always linked to vestibular processing problems
False. Not always a vestibular processing problem
What are the two main types of vestibular processing problems?
- Underactive vestibular-proprioceptive functions (under)
- Fearful and overwhelmed by vestibular sensations (over)
- Can have quality of life issues when system doesn’t work efficiently
T/F: It is rare that a child with just vestibular processing problem is referred when very young
True. Usually a mild problem and can still function. We see kids that are unable to make it work
Involves slow or inefficient processing of vestibular-proprioceptive functions
Underactive vestib-prop problems
How may an infant or toddler with an underactive vestib-prop system appear?
- Slower to master gravity
- difficult to assess when infants
- Usually see in a very subtle way
- Need to look at reflexes that are vestib. based e.g., moro reflex–doesn’t react when moves back in space
T/F: It is easy to assess underresponsive vestib-prop problems in infants
False. Need to look at reflexes e.g., with moro reflex, doesn’t react when moves back in space
How may preschoolers and kindergarteners with underactive vestib-prop systems appear?
-Difficulty adapting to preschool challenges involving postural control
How may school-age children with underactive vestib-prop functions appear?
- Lay on ground
- Postural control not too good
- Ask parents if ride tricycle with pedals
- May seek lots of vestib input e.g., run, jump twirl
A child who seeks a lot of vestibular input e.g., run, jump, twirl, may have what kind of problem?
Underactive vestibular-proprioceptive problem
Problem that involves over-responsiveness and anxiety with vestibular sensations
Gravitational insecurity
An infant or toddler with this problem will be distressed every time the parent moves him/her
Gravitational insecurity. Child may cry or bite
A preschooler who does the following probably has what condition?
- Fearful of movement
- Fear of being above ground
- moves slow
- Shuffles
- Won’t climb
GI
A school-aged child with a limited reperatoire of movement strategies and participation in gross motor activities probably has what condition?
GI
T/F: A child with GI may end of having motor planning problems
True
How many adults react to children with GI?
- Parents: puzzlement, anxiety, frustration, irritation, anger, anger, disappointment
- Teachers: impatience, mislabeling
How can SI problems shape the identity of a child? How can we prevent negative self-perceptions?
- Often identify self as lazy, shy, difficult, problem child b/c heard so many times
- Treat as early as possible
How do children with vestibular difficulties generally respond to intervention?
Respond well to intervention:
- Improvements in postural and general motor control
- Improvements in comfort with movement sensations
- Improvements in confidence and motor skills
- Provide education to parents/teachers
T/F: Ayres found that children who are overresponsive to vestib respond better to therapy
False. Kids underresponsive to vestib. respond better to therapy
Structure housed within the bony labrinth of the temporal bone that is oriented in three planes and responds to movement in three different ways
Semicircular canals
Contains three paired structures (superior, posterior, horizontal) that are oriented at right angles to each other, and therefor detect movement of the head in three dimensional space
Semicircular canals, within the bony labrinth of the temporal bone
The post-rotary nystagmus test tests the function of what structure?
The horizontal semicircular canal. Must put head at 30 degrees of flexion when doing test to put horizontal canal in right position
Structure that responds to angular movement: acceleration and deceleration
Semicircular canal.
T/F: When a child is spinning around without moving his head, he is exciting his vestibular system
False. Not doing much with vestibular system when head isn’t moving
T/F: The semicircular canals respond to constant velocity
False. With constant velocity without acceleration or deceleration, receptors align and won’t respond.
Why do you do the post-nystagmus rotary test in two different directions?
Because constant velocity without acceleration or deceleration will keep the receptors of the semicircular canals aligned, so they won’t respond
T/F: if a child is sensitive to vestibular input, you should provide him with what kind of input
Prop. But be careful–can get sick afterward
What part of the semicircular canals send impulses to the vestibulocochlear nerve during angular momentum?
Movement/bending of hair cells send impulses during angular movementum (acceleration or deceleration)
T/F: semicircular canals only respond to linear movement.
False. Semicircular canals only respond to angular acceleration. Otolith organs respond to linear acceleration
Housed at the base of the semicircular canals
Otolith organs
T/F: Utricle otolith organ has receptors oriented horizontally while saccule otolith organ has receptors oriented vertically
True.
Vestibular structure that is always working, even when standing in an upright position
Otolith receptors, utricle and saccule. As long as there is gravity, there is a response (unlike semicircular canal) b/c pressure on hair cells
Hair cells of this structure sends impulses during rate of linear head movement and static position of head in space
Otolith receptors, utricle(horizontal) and saccule (vertical)
T/F: Any head position or movement generates vestib. stimulation
true
Which system provides the brain with a reference point for spatial orientation?
Spatial orientation
Which structure is critical for us due to the pull of gravity
Otoliths
When using vestibular stim. in tx, you must consider…
- Head position and plane of movement
- Speed or velocity of movement
- Linear vs. angular movement
- velocity change vs. constancy
T/F: If a child is swinging and moving very slowly, he is receiving a lot of vestib. input
False. Going to be little input that he is getting
Linear AND angular movement
Arc movement
T/F: The semicircular canals will respond more when moving farther away from the body axis
False. The closer to the body axis, the more the semicircular canals will react
T/F: When moving in a tight circle, mostly the otoliths are working
False. When moving in a tight circle, mostly semicircular is working.
T/F: Semicircular movements are more important to the vestibular system than linear movements
True.
When moving in larger circles/arcs, what structure/s are at work?
Semicircular canal and otoliths (semicircular and linear input)
If you spin a child in tight circles and he wants to do it again, what does this mean?
He is underresponsive to vestibular input
Relays vestibular info down the spinal cord, to nearby structures of the brainstem and cerebullum, and upward to higher centers of the brain
The four vestibular nuclei, on each side of the brainstem
- Superior
- Medial
- Lateral
- Inferior
If a child has poor extension against gravity, this is probably due to: A. Reticular Formation via Vestibular B. Lateral Vestibular Spinal Tract C. Vestibular and Cerebellum D. Medial vestibular spinal tract
B. Lateral vestibular spinal tract influences antigravity extension
How does the vestibular system influence a great variety of functions in the body?
Via its connections
How does the vestibular system affect the lateral vestibular spinal tract?
vestibular nuclei descends down LVST pathway that goes to musculature in the trunk–important in antigravity extension
How does the vestibular system affect the medial vestibular spinal tact?
vestibular nuclei descends down MVST to the neck and upper trunk–important for co-contraction/proximal joint stability related to the upper neck and trunk
If a child has poor co-contraction, this is probably due to... A. Reticular Formation via Vestibular B. Lateral Vestibular Spinal Tract C. Vestibular and Cerebellum D. Medial vestibular spinal tract
D. MVST. Important for co-contraction/proximal joint stability related to the upper neck and trunk
How does the vestibular system affect the cerebellum?
Brain stem pathway allows the vestibular nuclei to cross over to the cerebellum (vestibulocerebellar pathways), affecting postural control and integrates with proprioception
If a child has poor postural control, this may be due to: A. Reticular Formation via Vestibular B. Lateral Vestibular Spinal Tract C. Vestibular and Cerebellum D. Medial vestibular spinal tract
C. Vestibular and cerebellum. Vestibular nuclei cross over to cerebellum, affected postural control and integrates with prop
How does the vestibular system affect bilateral motor control?
At the level of the vestibular system, the vestibular nuclei goes in both directions, thus affecting bilateral motor control (coordinates both sides of the body)
How does the vestibular system affect the reticular formation/arousal?
A. The vestibular nuclei ascends to the reticular formation/limbic system, thus affecting arousal
How does the vestibular system affect emotional regulation?
The vestibular nuclei ascends to the reticular/limbic system, thus affecting emotions e.g., GI
Why is the vestibular system important for maintaining a stable filed of vision?
At the brain stem level, the vestibular nuclei have connections with the ocular system, thus impacting maintaining a stable field of vision (motor/vestib. occular connection)
-What you check for with PRN test
Why is the vestibular system important for spacial relations?
The vestibular nuclei ascend to the cortex, influencing perception of space (spacial relations)
Central connections from the vestibular nuclei include…
A. Descending to spinal cord
B. To nearby structures in the brain stem (cerebellum, reticular formation, extraocular muscles)
C. Ascending to reticulo-limblic system, cortex
The Lateral vestibulospinal tract (LVST), Medial vestibulospinal tract (MVST), and the reticulospinal tract are the three _______
The LVST, MVST, and reticulospinal tract are the three vestibulospinal descending pathways
What structures are responsible for:
- Influencing extensor muscle tone
- Integrating vestibular with visual and prop info (head stability, head righting and equilibrium rxns)
- Can activate autonomic effects
The vestibulospinal pathways (LVST, MVST, reiticulospinal tract)
Which structure conveys primarily otolith organ inputs (antigravity)
The lateral vestibulospinal tract (LVST)
T/F: The Lateral vestibulospinaal tract conveys primarily semicircular canal inputs while the MVST conveys mostly otolith organ inputs
False. The LVST conveys mostly otolith organ inputs (antigravity/extensor muscle) while the MVST conveys mostly semicircular canal inputs (neck and upper trunk muscles, co-contraction)
How does the vestib. system interact with prop?
- Vestib. activity alters muscle activity, hence prop input
- Prop input inhibits activity in the vestibular nuclei via prop directly to the vestib. nuclei and prop input to cerebellum that projects back to vestib. nuclei
Responsible for neck and upper trunk muscle facilitation/inhibition and co-contraction via the semi-circular canals
MVST
Responsible for extensor muscles and antigravity movements
LVST
Regulates muscle tone throughout body when we are not moving, has both excitatory and inhibitory influence, and projects to the ANS
The reticulospinal tract
Influences alertness in response to vestibular input
Reticular formation
T/F: Slow rhythmic vestib. input increases arousal while rapid unpredictable vestib. input decreases arousal
False. Slow rhythmical vestib decreases arousal while rapid unpredictable vestib. input increases arousal
Vestibular Pathways with extensive connections that mediate proprioception
Vestibulocerebellar pathways
Send ascending info from the vestib. system to cranial nerve centers for compensatory eye movements
Vestibulo ocular pathways -vestib. input activates eye movements in predictable ways
If a child does not maintain a stable field of vision or his eyes move in the same direction as his head, this is probably not working correctly
Vestibulo-occular reflex (VOR)
Normal reflexive eye movements introduced by angular acceleration
Vestibular nystagmus
T/F: Per-rotary nystagmus occurs when the eyes beat slowly in the direction of the rotation while post-rotary nystagmus occurs when the eyes beat in the opposite direction of rotation back to midline
True. PRN is mediated by CNS probably in brainstem
Duration of postrotary nystagmus reflects duration of rotation. This is called ________
Velocity storage.
T/F: Unusually short postrotary nystagmus by indicate brainstem inefficiency. However, duration is not usually affected by arousal level and visual stimulation
False. Duration is also normally affected by arousal level and visual stimulation
Visually based illusion of movement
Vection
Eyes follow motion of moving visual field with contrasting vertical bars and snap back rhythmically.
Optokinetic nystagmus. Induced by visual system activity alone and used to measure central vestib. system in research
Continuation of nystagmus after optokinetic nystagmus stops, reflects central vestib. function
Optokinetic after-nystagmus
Nystagmus that occurs without vestibular or visual stimulus
spontaneous nystagmus
Nystagmus that occurs following a change in head position
Positional nystagmus
Nystagmus that occurs following a shift in gaze
Gaze nystagmus
Nystagmus that produces constant shimmering eye movements; probably genetic in origin
congenital nystagmus
The _______ and visual systems work together to mediate eye movements
The vestibular and visual systems work together to mediate eye movements
T/F: The vestibular system controls all types of eye movements
False
T/F: Postrotary nystagmus is a pure vestibular measure
False. It is influenced by light, vision, and arousal level
Ascending vestib. pathway that influences emotoinal responses to vestib. stimulation and increased eye contact during vestib. stimulation
Reticular-limbic pathways, project to reticular system and then to limbic structures, thalamus, and hypothalamus
Prolonged postratary nystamgus may indicate dysfunction where?
At higher level cortical areas i.e., inadequate inhibition
Region of the cortex that is responsible for processing vestibular input related to spatial aspects of body self-consciousness
Temporoparietal junction (TPJ)
Region of the cortex that is responsible for processing vestibular input related to position and movement of the head
Parietoinsular vestibular cortex (PIVC)
Region of the cortex responsible for processing vestibular input related to vestibular and visual
Medial superior temporal region (MST)
Region of the cortex responsible for processing vestibular input related to the body and world-centered space reference
Ventral intraparietal region (VIP)
System that integrates sensory info from the personal space (somatosensory, prop, visual, and auditory signals) with signals from the extrapersonal space (visual and auditory)
Central vestibular system
Contributes to generating spatial representation of the bodily self in relation to the external world (self location and self consciousness)
Central vestibular system
T/F: All natural vestibular stimuli are multimodal
True
The only system lacking a primary sensory cortex
Central vestibular system
T/F: Vestibular percept of body position is always endocentric (relative to self)
False. Vestibular percept of body position is always exocentric (relative to surrounding space )
Structures in vertebrates that contribute to spatial orientation
Vestibular labrynths in vertebrates contribute to spatial orientation-similar across vertebrates
Why did central relays e.g., vestibular nuclei, reticular information originally develop?
To interpret vestibular sensation and translate it into motor responses (similar to development of labrynths)
At 6 months, this structure matures and is evident when baby does the landau reflex (prone extension)
The lateral vestibulospinal tract –antigravity, otoliths
T/F: the duration of postrotary nystagmus generally decreases with age
False. Generally rises with age
T/F: According to SI theory, vestibular bilateral disorders (postural/ocular disorders) and modulation disorders (GI and aversion to movement) are both Peripheral vestibular processing problems
False, according to SI theory, they are central vestibular processing theories
T/F: The following terms should be treated differently:
- Postural and bilteral integration
- Vestibular and bilateral integration
- Bilateral integration and sequencing (BIS)
- Vestibular-prop bilateral integration and sequencing
False. There is variation in terms used for the same type of problem:vestibular-bilateral problems
A child with the following signs may have what problem?
- Strong anxiety in response to vertical linear input (even very gentle movement)
- Slow guarded movement
- Avoidance of movement on surfaces that are unstable (even slightly) or at different heights)
GI
T/F: Vestibular under-responsiveness may involve seeking of intense vestib. input, especially rotary
True
How can you assess vestibular function via observation?
- Look for postural control and equilibrium responses
- Emotional responses: avoidance vs seeking out of specific kinds of movement sensations
What may be some alternative explanations for behavior related to poor vestibular functioning?
0Limited experiences compared with peers
-Neuromotor impairment
What standardized tests can you use to assess vestibular functioning?
The SIPT: SWB, PRN, BMC
BOT balance subtests
The following structured clinical observations will test for what?
Prone extension
Flat board reach, tilt board tip, tilt board reach
Supine over bolster, step backward
Vestibular functioning
What is the goal in tx when working with a child with vestibular processing difficulties?
An actively involved child who enjoys movement activity
When working with a child with vestib. processing problems, what should you be on the lookout for ?
- Linear vs. angular stimuli
- Sustained vs. transient stimuli
- Slow/position-related vs. fast/movement-related stimuli
When treating a child with vestib. processing problems, how can you use visual and prop input?
- Use increased prop through resistance and active movement to modulate vestib. input
- May give prop input passively (joint compression and traction), especially if child is over stimulated by vestibular input
- Manipulate visual environment (e.g.,add visual targets to inhibit vestib. input, dim lighted to facilitate vestibular input)
The following are classic core signs of what condition?
- Poor prone extension
- Slight hypotonicity, especially proximal extensors
- Poor co-contraction and proximal stability
- Poor balance reflected in low SWB score
- May crave intense vestibular stimulation
- Some may be posturally insecure
- May have depressed duration of PRN
Vestibular-Bilateral difficulties
T/F: According to theory, a child with vestibular bilateral difficulties has a under active central vestibular system due to brainstem based inefficiency
True
How may hemispheric specialization be affected in a child with vestibular-bilateral difficulties?
- Language delays
- Visual perceptual problems
- Delays in establishing hand preference
T/F: A child with vestibular-bilateral difficulties may appear normal with above average IQ
True. But may also:
- Affected by social context
- Clumsiness associated with poor balance
- Poor posture
- May seem weak
T/F: A child with vestibular-bilateral difficulties may appear normal with above average IQ
True. But may also:
- Affected by social context
- Clumsiness associated with poor balance
- Poor posture
- May seem weak
How can you increase challenges for a child with vestib-bilateral differences once you have first focused on simple postural-ocular responses?
- Increase challenge to balance and equilibrium (maybe best by transient inputs)
- Then increase challenges to bilateral integration, including bilateral projected action sequences if these are problematic
Involves anticipation of when to move and is graded from simple to complex (kicking ball that is still while you are still –>run to kick ball that is still–>kick ball moving toward you when you stand in one place –>run to kick ball that is rolling)
Bilateral projected action sequences
Involves anticipation of when to move and is graded from simple to complex (kicking ball that is still while you are still –>run to kick ball that is still–>kick ball moving toward you when you stand in one place –>run to kick ball that is rolling)
Bilateral projected action sequences
The following problems are all associated with what problem?
- Fear of everyday movement experiences
- Changes in vertical space are different
- Avoidance of new head positions
- Anxiety when feet are away from floor
- Extremely cautious and restricted movement
- Emotional and behavior problems common
GI
The following would explain what condition?
- Poor vestibular modulation of otolith input
- Prop problem involving inadequate modulation of vestib. input
GI
When working with a child with GI, how can you grade interventions?
- Start with activities child can tolerate; usually involves keeping feet or body on or close to floor with limited movement
- Gradually increase demands for excursion through space, but challenges must be finely graded
- Stay very close to child initially to give physical support, slowly moving away and supporting less frequently
- Be sure to address other modulation, postural, and praxis issues as child expands repertoire of movement experiences
When working with a child with GI, as he expands his repertoire of movement experiences, what do you need to also address?
Be sure to address other modulation, postural, and praxis issues
Strong feelings of discomfort, nausea, vomiting, dizziness, or vertigo following angular acceleration, especially rotation
Intolerance to movement
Theory behind why a child has an intolerance to movement
Poor modulation of semicircular canal input
T/F: OTs will normally treat children with intolerance to movment
False. Not treat by OT if no other signs of SI are present. May have to address if coexists with other conditions being treated
When present in SI tx (if coexists with other conditions being treated), how should intolerance to movement by addressed?
-Avoid/reduce intensity of angular acceleration and use strong doses of prop during vestib. activities
