Vestibular Treatment

Original Editor - Jess Bell based on the course by Bernard Tonks
Top Contributors - Jess Bell, Kim Jackson, Olajumoke Ogunleye and Robin Tacchetti

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Introduction

Vestibular disturbance is a significant issue globally, with 80 percent of people aged over 65 years experiencing dizziness. Individuals who have vestibular impairment generally have problems with gaze stability, motion stability, balance and postural control. Vestibular rehabilitation is an evidence-based approach to managing these issues.

Goals of Treatment

The focus of vestibular rehabilitation is to:

• Improve postural control and balance
• Improve the patient’s ability to see clearly during head movement (gaze stability)
• Improve the patient’s overall general physical condition
• Reduce the patient’s social isolation
• Decrease the patient’s motion sensitivity

For treatment to be effective, an appropriate home exercise programme and patient compliance are essential. It is also important that patients feel that their programme is manageable and within their level of ability.

Patient Tips

The following advice can be useful for patients engaging in vestibular rehabilitation programmes:

• “What makes you a little bit dizzy is good for you” (for chronic vestibular hypofunction)
• “You don’t have to overdo it for the exercises to work - you just need to make yourself mild to moderately dizzy, but it should settle fairly quickly”
• “You don’t need to do all the exercises at once. It’s better to do brief, multiple episodes of exercises during the day”
• “It can be helpful to engage in ‘grounding’ or ‘calming’ strategies before and even during the exercises”

Decompensation

It is important for patients and clinicians to understand that recovery following vestibular loss may be tenuous. Patients may experience a recurrence in symptoms or relapse with fatigue or stress, prolonged periods of inactivity, illness or occasionally a change in certain medications. This is termed ‘decompensation’.

Predictors of Outcome

The following factors are predictive of a better prognosis in vestibular patients:

• Patients who have less initial disability
• Patients who are seen earlier after onset
• Patients with stable unilateral vestibular deficits
• Partially compensated patients whose symptoms are provoked only by movement

Treatment Approaches

Surface Orientation Exercises

Surface orientation exercises are performed as follows:

• Patients lie on a firm surface (i.e. bed or floor)
  • Alternatively they can sit or stand
• Patients breathe deeply and relax
• They should concentrate on the sensation of lying quietly on the bed and remain quiet / still for 5 to 10 seconds
• They should then close their eyes for five seconds

These exercises draw the patient’s attention to somatosensory input, which can have a positive effect on this patient group. It can help to calm the central nervous system, improve sensory integration and enhance postural control and balance. They are particularly useful for post-concussion syndrome patients.

Vision Exercises

Vision exercises can be introduced in the following order:

• Peripheral field expansion
  • Soften gaze and work  on increasing peripheral visual field awareness
• Smooth pursuits
• Saccades
  • Percon and Wall Clock exercises

Peripheral field expansion

Soft Focus

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100 Number Exercise

NUMBER GRID

The purpose of this exercise is to stimulate a patient’s peripheral visual fields in a tabletop activity. When patients learn to actively ‘soften’ their gaze, visual information can enter without using their focal system. The exercise is performed as follows:

• The patient sits with the 100 letter grid lying flat on the table, or on an angle using an incline board
• Patients are asked to choose a letter to look at
• Without moving the focus of their vision from this letter, they aim to see as many letters as possible away from the centre letter

NB: The harder patients try to ‘focus’, the worse they tend to perform. It is, therefore, important that patients ‘soften’ their gaze in order to see the peripheral letters. Some patients may wish to use ‘blinders’ to block other letters if focusing on a certain block of letters.

Saccade Training

Wall Clock Saccades

This exercise is performed as follows:

• The patient stands in front of a wall
• 12 visual targets are placed on the wall (e.g. post-its) in a circle like a clock
• Place an X in the middle of the clock
• Patients are instructed to move their eyes as quickly as possible from each post-it note to the centre X, moving first in a clockwise and then in a counter-clockwise direction
• This exercise can be combined with gaze stability exercises (see below)

Adaptation or Gaze Stability Exercises

These exercises aim to:

• Increase the gain of the vestibulo-ocular reflex (VOR)
  • VOR gain is defined as the amount of eye rotation relative to the amount of head rotation
  • It should be near unity (i.e. close to 1)

• Improve visual acuity with head movement
• Decrease dizziness with head movement

They are indicated when patients have:

• Oscillopsia
• Decreased visual acuity with head motion (positive head thrust or dynamic visual acuity tests)
• Reports of blurring or jumping of the visual field with head movement

Adaptation Exercises

Adaptation exercises are aimed at “inducing long-term changes in the neuronal response of the vestibular system to a specific error signal – retinal slip.”

They should lead to adaptation (i.e. when there is an error signal, the central nervous system tries to reduce it, and modifies gain of the vestibular system.

They aim to:

• Reduce the amount of visual blurring during head movements

• Improve postural stability
• Reduce symptoms

Essentially, adaptation exercises require patients to move their head while focusing on a small stationary target (or a target that moves in the opposite direction of the head movements). It is possible to use a tennis ball on a string to create a moving target. Additional challenges can be added (walking forwards or backwards) It should be noted that:

• Adaptation takes time
• It is context specific, so it is necessary to vary the exercise
• Adaptation is affected by voluntary control
• It is necessary to keep the target in focus

Treatment Variables:

• Duration: 1-2 minutes - (Tonks has found that clinically patients respond well to sets lasting less than 90 seconds)
• Add in background distraction
• Change body position (e.g. sit, to stand to walk)
• Alter speed (slow to fast)
• Vary frequency (2 to 3 timers per day, 5 days per week)
• Alter distance from target (3ft (0.9m), 8ft (2.4m), 10ft (3m))

Adaptation of the Vestibulo-Ocular Reflex (VOR)

• The aim of these exercises is to increase the gain of the VOR

• After an acute unilateral vestibular lesion (UVL), VOR gain returns to normal in 1 to 3 months, but only with low frequencies of head movement
• During rapid, unpredictable head movements toward the lesioned side, there is a marked deficit in VOR function
• Retinal slip results in an error signal that the brain attempts to minimise by increasing the gain of the vestibular system (adaptation)
• Gaze stabilisation exercises assume that repeated periods of retinal slip will induce adaptation

Adapting VOR gain

• Adapting VOR gain works well for lower frequencies of head movement

• For higher frequencies of head movement, a substitution strategy involving saccades is more effective
• Covert saccades are very important in the recovery of gaze stability
  • They are also beneficial for the dynamic visual acuity of patients with bilateral vestibular hypofunction

NB: Covert saccades occur during the head rotation and cannot be seen. Overt saccades occur after the head rotation ends and can be seen. Riska and colleagues have found that: 

• UVL Patients who have primarily covert saccades have better performance on dynamic visual acuity, gait and balance measures - i.e. a reduced falls risk
• Individuals who rely on overt saccades or a combination of overt and covert saccades are more likely to have an abnormal gait speed and be at risk of falls based on DGI score