Clinical balance assessments

Balance assessments are carried out by audiologists that are specialists in hearing and balance. A referral needs to be made by your GP or an ear nose and throat (ENT) doctor.

General balance assessment
Infrared video nystagmography (VNG)
Rotary chair system

A general balance assessment

Taking your history

In all cases, the individual's history is taken before the balance assessment begins.  These questions will help the audiologists decide which tests are necessary to find out the cause of your imbalance. On average, a full balance assessment lasts between 1 ½ hours and 2 hours in length.

How to prepare for your test

Prior to your appointment date

Please ensure that your ear canals are free from ear wax and infection. You can do this by making an appointment with your GP or nurse so that they can check this for you.

Also, please speak to your GP about stopping any medication that has been prescribed to control your dizziness 48 hours before your appointment. Please do not stop taking any other medication you are taking unless advised by your doctor. Always consult your GP about your medication.

It is advised that you should bring a friend or relative with you if you have balance problems, however, if you chose to come alone, it is recommended that you wait for a minimum of 45 minutes before leaving the hospital [RSCH, 2011].

Two days before your appointment

Do not consume any alcohol or recreational drugs.

On the appointment day

  • Do not take any sleeping tablets the night before the test. However, do not stop any other medication you are taking unless advised by your doctor. Contact your GP if you are unsure.
  • Do not wear any make-up on the day of the test.
  • Do not put on greasy creams on your face and/or neck on the day of the test.
  • Avoid having a heavy meal on the morning of your test. It is recommended that you have a light meal and drink normally on the day of your test.
  • Avoid wearing unsuitable clothing. All individuals being assessed should wear trousers as one of the assessments may involve the individual wearing a safety harness.

The balance system

This system is the coordination of information from three sources in your body [RSCH, 2011]. These sources are:

  • Your visual system
  • Your proprioceptive system (this is information about the position of your feet, limbs and joints)
  • Your vestibular system (this is information from your balance organs in your inner ear)

Your brain processes all of this information and makes sure that everything is in sync and is responsive when your movements suddenly change. For example if you suddenly trip over a rock, your balance system reacts to ensure that you do not trip over. The aim of a balance assessment is to test whether this system is working properly.

Image, extracted from the University of Minnesota Children’s Hospital, illustrates the body’s balance system [UOM, 2013].

Infrared video nystagmography (VNG)

Why the test is carried out

This form of assessment records involuntary eye movements, called nystagmus, in a video format; enabling the examiner to carry out an analysis and determine whether or not the dizziness experienced by the individual, is due to an inner ear disorder.

How the test is performed

This assessment is carried out via the following steps:

  1. The individual is given hi-tech video goggles with infrared cameras to wear, in order for eye movements to be recorded and assessed.
  2. Once worn, the individual is then asked to look at objects or lie in different positions according to the specific VNG assessment being carried out.
    • Saccade test: evaluates rapid eye movement.
    • Tracking test: evaluates movement of the eyes as they follow a visual target.
    • Positional test: measures dizziness associated with the position of the head.
    • Caloric test (sometimes called ENG): measures the individual’s response to the presence of warm and cold water in the ear canal via a soft tube.
  3. The hi-tech goggles are connected to a display screen which shows the recorded eye movements of the individual.
  4. This assessment lasts approximately an hour and a half.

Rotary chair system

Why the test is performed

The vestibulo-ocular reflex (VOR) is the interaction between the visual and vestibular systems. This reflex functions to maintain visual clarity of objects during head movement by maintaining the image at the centre of the retina [Medline. 2012].

The VOR is assessed via the rotary chair. If an individual suffers from dizziness, this assessment can determine whether or not the cause is due to a problem with the inner ear or whether the cause is associated with a disorder of the brain.

How the test is performed

The test is carried out in a darkened room. The rotational chair may be positioned in a booth. In this case, the examiner will be positioned outside of the booth during the assessment.

The individual will be asked to keep focus on a red light that will be moving or to keep focus on a stripey curtain that will be moving around the individual [Medscape, 2012].

Eye movement is assessed via the use of electrodes or by the use of an infrared camera, which is placed directly in front of the individual.

How the test is performed

This assessment is carried out via the following steps:

  1. The individual sits in the rotational chair. This chair has a head restraint and a two-way system.
  2. Monitoring eye movement: using electrodes
    1. Prior to the electrodes being placed, the area of skin where the electrodes are going to be placed is cleansed of any oil or debris with alcohol and prepared with an electrode prep pad.
    2. The electrodes are then placed on the corner of the eye, where the upper and lower eyelids meet (edge of your eye nearest to your ear).
    3. Electrodes may also be placed on the individual’s forehead or earlobe.
    4. The electrodes are then connected to the computer.
  3. Monitoring eye movement: infrared light
    1. If infrared is used: the camera will already be in place and step 4 is carried out.
  4. The individual's head is then retrained and the camera is positioned so that the examiner is able to monitor the individual’s eye movement outside of the booth.
  5. Once everything is in place and set-up is completed the testing can then begin.
  6. This assessment is made up of 8 parts. The longest lasting 3 minutes [University Otolarynology,2013].
  7. The entire assessment should not exceed 30 minutes.

The results are assessed either by the recordings from the electrode or via the video recorded by the infrared camera.

Things to keep in mind during the test

It is important that the individual keeps his/her eyes open during the assessment.

The rotational chair may tilt the individual's head forward at 30 degrees [Medscape, 2012].

There is a two-way communication system so the individual can be in constant communication with the examiner.

 


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Created: July 2014
Review due: May 2016

First published: Wednesday 23 July 2014
Updated: Tuesday 22 December 2015