Summary Neuro 3 - Vereeck - Vestibular rehabilitation

Neurological physio 3 – Vereeck Loranne den Otter



Vestibular rehabilitation
H1: Components and tasks (function) of the vestibular system
▪ Input
▪ Integration
▪ Output

1. Input
Different types of receptors
(input) -> Which, what kind of info and how can we find them?
▪ Type of information?
▪ How can we test them?

1.1. Proprioception
Type of information:
▪ Position sense
▪ Movement sense

Assessment:
▪ Mirror movements
▪ Thumb finding test
▪ …
▪ reposition test, each joint separately
▪ Proprioceptie kunnen testen -> terug opzoeken

1.2. Labyrinth
Type of information:
▪ Position of head in gravitational space
▪ Linear acceleration of head
▪ Rotational accelerations of head acceleration, not speed

Assessment:
▪ Bedside tests (clinical)
– Head Impulse test
– Head Shaking test
– Dix-Hallpike test
– and other ...
▪ Vestibular function tests
– Binaural Bithermal Caloric test
– and other ...

1.3. Vision
Type of information:
▪ Detection of obstacles in environment (proactive scanning of the environment – important
aspect of feedforward)
▪ Detection of own movement with respect to stationary objects (e.g. fear of heights)
▪ Visual orientation (‘vertical’ reference frame)

,Neurological physio 3 – Vereeck Loranne den Otter


1.2.1. Detection of obstacles in environment
1.2.1.1. Assessment of vision and oculomotor skills in function of maintaining balance
Vision -> zijn er obstakels die gevaarlijk zijn in jouw omgeving?
▪ Visual acuity = gezichtsscherpte
– Different optotypes can be used (Snellen chart (E), Landolt C, Bailey & Lovie chart,...)
▪ Contrast sensitivity, front background recognition, depth perception,...



𝑙𝑜𝑔𝑀𝐴𝑅 𝑠𝑐𝑜𝑟𝑒 = 1.10 − (𝑇𝑐 × 𝐿𝑣), where Tc is the
number of correctly read letters and Lv is the value of
a letter 0,02

5 symbolen op elke lijn
<-> andere chart waarbij er minder tekens zijn indien
groter

11 rijen boven normale lijn
score 0 —> als je ze alle 5 kan lezen, dan krijg je 0



Visual fields
▪ Confrontation test (screening for (gross) visual field defects)
▪ Meaning of visual field defects


Oculomotor skills
Relationship between vision and oculomotor skills
Oculomotor skills needed to scan the environment for possible obstacles
ogen kijken niet alleen rechtdoor, maar scannen heel je omgeving



▪ smooth pursuit eye movements

▪ Saccades
– = kijk snel van ene naar andere duim
– (snelle oogbewegingen)

▪ Vestibulo-ocularmovements

▪ Vergence (di- and convergence)




CAVE – do not forget ‘hemispatial visual neglect’

,Neurological physio 3 – Vereeck Loranne den Otter


1.2.2. Detection of own movement with respect to stationary objects (stilstaande objecten)
▪ Both central (projection of object gets bigger on retina) and peripheral (optic flow) vision
– Tendency to want to brake as a passenger in a fast-moving car
– If not working: e.g. rear-end collisions
– Sensorische geeft info over je eigen snelheid
– Wij krijgen zelf een idee over onze snelheid doordat objecten groter worden op onze
retina + we zien meer langs de zijkant wat ons opnieuw meer info geeft over onze
eigen snelheid
o Dit is relatief, visuele info is relatief

▪ Estimation of own postural sway relative to a fixed reference point
– Fear of heights
o Onzeker bij grote hoogtes waar we niks zien omdat we dan geen visuele info
krijgen → er is geen “fixed reference point”
– Geeft ook info over onze sway (kleine bewegingen)

Moving visual information (e.g. optic flow) can have a destabilizing effect


1.2.3. Visual orientation
▪ Vertical reference frame
– Correct perception of what is vertical, horizontal or orthogonal
– we kunnen visueel zien tot op 1 graad wat er recht is en wat niet

Assessment of the perception of verticality
▪ Subjective Visual Vertical (SVV) test
– Laserbeam / complete darkness
– Starting position 5° 10° 20° to the left and right
– Head neutral position and incliniation to left and right




1.3. Other sensory input
▪ Exteroception (light touch)
▪ Graviceptors = Any receptor that gives the brain information concerning the direction
of gravitational forces (and hence a sense of up and down)
▪ Sound
– (can interfere with interpretation (sound as a source of orientation) of clinical
balance tests such as Marche en étoile / Fukuda))
– mensen met en stoornis zullen afwijken
– geluid gebruiken om zich te navigeren in de omgeving → oefenzaal hieraan
aanpassen

, Neurological physio 3 – Vereeck Loranne den Otter


2. Integration
▪ Primary integrator: vestibular nuclei
▪ Secondary (adaptive) integrator: cerebellum




3. Output (tasks of the vestibular system)
3.1. Vestibulo-ocular Reflex




3.2. Vestibulo-Thalamo-Cortical projections




3.3. Vestibulo-Spinal Reflex