Vestibular rehabilitation
Vestibular system
Input
Sound
Can interfere with interpretation
• Sound as a source of orientation
Labyrinth
Position of head in gravitational space: linear & rotational accelerations
- Bedside tests (clinical): head impulse test, head shaking test, dix-hallpike test, ocular counter
roll test
- Vestibular function tests: caloric test, video head impulse test
Proprioception
Position and movement sense
- Mirror movements
- Thump finding test
Visual input
Detection of obstacles in the environment – proactive scanning as part of feedforward
,Assessment
Vision
- Visual acuity: ototypes (Snellen chart (E), Landolt)
- Contrast sensitivity, front background recognition
Visual fields
- Confrontation test: screening for gross visual field defects
Oculomotor skills: scan environment for possible obstacles
- Smooth pursuit eye movements
o Red dot moved left and right
o Not normal: jumping movement à central problem
- Con- & divergence
o Red dot moving closer and farther
o Normally able to see closer untill 7,5cm of nose
- Saccades
o Jumping from light to finger
o Overshooting / undershooting à vestibular problem
o Hypomovement: not far enough
- Optokinetic induced eye movements
o Visually induced nystagmus à normal
o Rest nystagmus à problem in peripheral/central system
- Vestibulo-ocular movements
CAVE: hemispatial visual neglect à central problem
Type of information
Detection of own movement with respect to stationary objects
- Corrective scanning to make sure we won’t fall
- Both central and peripheral vision
- Eg. Fear of heights
- Moving visual information: destabilizing eYect
Visual orientation: vertical reference frame
• Correct position of what is vertical, horizontal or orthogonal
• Subjective Visual Vertical (SVV) test
o Tilted laserbeam is presented à patient has to put line vertical
Other sensory input
Exteroception: light touch
Graviceptors: sens body’s position in relation to gravitational forces
Integration
Primary integrator: vestibular nuclei
Secondary (adaptive) integrator: cerebellum
,Output
Vestibulo-thalamo-cortical projections
Connections between vestibular system, thalamus and cortex
- Helps in orientation and navigation
Vestibulo-autonomic interactions
Connections between vestibular and autonomic system
• Something wrong with vestibular system: reaction in neurovagitive system: blood pressure,
heart rate
Vestibulo-spinal reflex
Tilt of body sensed à sent to vestibular nuclei à VSR: activates antigravity muscles à keep postural
control
, VOR: vestibulo-ocular reflex
Head movement sensed à sent to vestibular nuclei à VOR: sends eyes in opposite direction à gaze
stabilisation
Regulation of circadian rhythm
Vestibular influences on hypothalamic regulation of circadian rhythm
- Something wrong in vestibular system à diYerent sense of day and night, influencing sleeping
pattern
The labyrinth
Location
Located in temporal bone
Vestibular system
Input
Sound
Can interfere with interpretation
• Sound as a source of orientation
Labyrinth
Position of head in gravitational space: linear & rotational accelerations
- Bedside tests (clinical): head impulse test, head shaking test, dix-hallpike test, ocular counter
roll test
- Vestibular function tests: caloric test, video head impulse test
Proprioception
Position and movement sense
- Mirror movements
- Thump finding test
Visual input
Detection of obstacles in the environment – proactive scanning as part of feedforward
,Assessment
Vision
- Visual acuity: ototypes (Snellen chart (E), Landolt)
- Contrast sensitivity, front background recognition
Visual fields
- Confrontation test: screening for gross visual field defects
Oculomotor skills: scan environment for possible obstacles
- Smooth pursuit eye movements
o Red dot moved left and right
o Not normal: jumping movement à central problem
- Con- & divergence
o Red dot moving closer and farther
o Normally able to see closer untill 7,5cm of nose
- Saccades
o Jumping from light to finger
o Overshooting / undershooting à vestibular problem
o Hypomovement: not far enough
- Optokinetic induced eye movements
o Visually induced nystagmus à normal
o Rest nystagmus à problem in peripheral/central system
- Vestibulo-ocular movements
CAVE: hemispatial visual neglect à central problem
Type of information
Detection of own movement with respect to stationary objects
- Corrective scanning to make sure we won’t fall
- Both central and peripheral vision
- Eg. Fear of heights
- Moving visual information: destabilizing eYect
Visual orientation: vertical reference frame
• Correct position of what is vertical, horizontal or orthogonal
• Subjective Visual Vertical (SVV) test
o Tilted laserbeam is presented à patient has to put line vertical
Other sensory input
Exteroception: light touch
Graviceptors: sens body’s position in relation to gravitational forces
Integration
Primary integrator: vestibular nuclei
Secondary (adaptive) integrator: cerebellum
,Output
Vestibulo-thalamo-cortical projections
Connections between vestibular system, thalamus and cortex
- Helps in orientation and navigation
Vestibulo-autonomic interactions
Connections between vestibular and autonomic system
• Something wrong with vestibular system: reaction in neurovagitive system: blood pressure,
heart rate
Vestibulo-spinal reflex
Tilt of body sensed à sent to vestibular nuclei à VSR: activates antigravity muscles à keep postural
control
, VOR: vestibulo-ocular reflex
Head movement sensed à sent to vestibular nuclei à VOR: sends eyes in opposite direction à gaze
stabilisation
Regulation of circadian rhythm
Vestibular influences on hypothalamic regulation of circadian rhythm
- Something wrong in vestibular system à diYerent sense of day and night, influencing sleeping
pattern
The labyrinth
Location
Located in temporal bone
