L17: Vestibular rehabilitation Flashcards
What are 6 problem-based approach to planning treatment programs?
- Visual blurring or dizziness during tasks that require stable vision
- Training of gaze stability and / or visual tracking
- Symptoms of dizziness / vertigo exacerbated during movements
- Habituation exercises
- Difficulties maintaining static or dynamic equilibrium
- Exercises to target the identified deficits
- eg unable to maintain postural stability eyes closed on foam
- Instability when walking
- Exercises to improve stability during gait
- Physical deconditioning
- Exercises targeted at improving fitness and strength
- Return to driving
What are the 4 different issues in regards to vestibular problems?
- Unilateral peripheral vestibulopathy
- Bilateral peripheral vestibulopathy
- Central nervous system dysfunction
- Mixed central and peripheral
What are 2 things that can move image off fovea?
- Movement of fovea (ie head)
- Movement of object itself
When is the vestibular system (i.e VOR) used?
When fovea moves
- Eg when jogging
When is the visual system (i.e VOR) used?
When object moves in space
- Following the path of a tennis ball during a game VOR
Visual system is used for____ (high/low)-frequency movements
low
Smooth pursuit is like a reverse of ____
VOR
When is smooth pursuit used?
Occurs in the absence of vestibular stimulation i.e. VOR needs to be cancelled “follow the finger”
Smooth pursuit is ____ modulated
centrally
When is the saccadic system used?
Is used to follow moving unpredictable targets
- Eg trying to swat a fly
Saccadic system is _____ mediated.
centrally
What is the optokinetic system?
Takes over from the vestibular system when head movements are too large
- Eg. system that kicks in when on a train watching fast things go pass
The optokinetic system has pathways similar to that of ______.
smooth pursuit
What is the vergence system?
- Depth tracking
- Pathways in the parietal, occipital, and frontal regions
What is the fixation system?
- Utilized to look at stationary object
- Pathways in the occipital region
- Stabilise the eye –.> Fixate on an object
If there is damage to the brainstem (eg. pons), what can the problem be?
have difficulty controlling these systems (optokinetic, vergence, fixation system)
What are the 3 characteristics in the final common pathway?
- horizontal eye movements controlled in pons
- vertical and torsional eye movements controlled in the midbrain
- descending modulations from supranuclear structures
The ____ is one of the fastest reflexes.
VOR
What are 4 characteristics of the VOR?
- 10-20ms latency
- 3 neurone circuit
- Less effective in dealing with slow or prolonged movement
- Sensitive to acceleration NOT constant velocity
What should you check before VOR?
Check saccades first –> if this is poor –> break down of VOR
What does saccadic pursuit look like?
What does VOR look like?
eyes opposite to head to keep gaze stable
What is a gain of the vestibular system?
Gain = output /input
i.e. eye mvt/head mvt
What is a gain of 1?
eye movement velocity = head movement velocity
What is a gain of 0.5?
eye movement velocity less than head movement velocity
The gain is _____ (increased/decreased) with vestibular loss.
increased
What is the purpose of gaze stabilisation exercises?
Recovery of the dynamic vestibulo-ocular responses is due to the adaptive capability - neuroplasticity - of the central vestibular system
ie. the ability of the vestibular system to make long-term changes in the neuronal response to input
What is the signal for inducing vestibular adaptation?
Retinal slip
What is the retinal slip?
movement of a visual image across the retina (Blurring of movements)
What does a retinal slip result in?
an error signal that the brain attempts to minimise by increasing the gain of the vestibular responses
What does the recovery of dynamic vestibular function require?
both visual input and movement of the body and head
When should x1 and x2 gaze stability exercises be used?
- Improves gaze stability by utilising central preprogramming ie neuroplasticity
- Pre-programing the saccade to compensate for the lack of VOR
Unilateral Vestibulopathy (UVL) usually improves in ____-_____ weeks
4-6
What gaze stabilisation exercises should be used for bilateral Vestibulopathy (BVL)?
- x 1 most useful, majority can’t ever manage x 2
- can take up to 12 weeks to improve
What are the 5 guidelines for gaze stabilisation exercises?
- Consider the stimulus
- the best stimuli are those that incorporate movement of the head and visual input
- Response to exercise takes time but repeated short bursts are effective
- vestibular adaptation can be induced with periods of stimulation of 1-2 minutes
- Changes in the vestibulo-ocular system are context specific
- exercises must stress the system in different ways
- different frequencies of head movement - variable
- different head positions
- Neuroplastic change requires focus on the task
- mental effort will help improve the gain of the system
- patients should be encouraged to concentrate on the task
- Patients should always work at the limit of their ability
- exercises should stress the patient’s ability ie need to provoke symptoms to reduce symptoms
What is the guideline for gaze stabilisation exercises when “considering the stimulus”?
the best stimuli are those that incorporate movement of the head and visual input
What is the guideline for gaze stabilisation exercises in “response to exercise taking time but repeated short bursts are effective”?
vestibular adaptation can be induced with periods of stimulation of 1-2 minutes 5-6 mins
- X 5-6 times a day rather than 1 hr X 1 time a day
What are 3 guideline for gaze stabilisation exercises when “changes in the vestibulo-ocular system are context specific”?
- exercises must stress the system in different ways
- different frequencies of head movement - variable
- different head positions
What are 2 guidelines for gaze stabilisation exercises when “neuroplastic change requires focus on the task”?
- mental effort will help improve the gain of the system
- patients should be encouraged to concentrate on the task
What is the guideline for gaze stabilisation exercises when “patients should always work at the limit of their ability”?
exercises should stress the patient’s ability ie need to provoke symptoms to reduce symptoms
What is the Herdman protocol for gaze stabilisation training in terms of duration?
begin with 1 minute each progress to 2 minutes each aim for continual motion, slow down rather than stop
What is the Herdman protocol for gaze stabilisation training in terms of frequency?
3 to 5 times/day, aim for x5
What is the Herdman protocol for gaze stabilisation training in terms of plane of movement?
start with horizontal and add vertical only use roll plane in specific contexts eg pilots
What is the Herdman protocol for gaze stabilisation training in terms of distance?
near first, then near and far
What is the Herdman protocol for gaze stabilisation training in terms of speed?
slowly at first should always see clearly, but at upper limit of ability - need a little retinal slip
What is the Herdman protocol for gaze stabilisation training in terms of position?
start in sitting and progress as quickly as possible to standing to progress, change foot position
What is the Herdman protocol for gaze stabilisation training in terms of background?
plain wall, target away from wall progress to busy background