What is a Balance Test? I Balance & Dizziness
Dizziness, lightheadedness and vertigo are some of the most common health problems experienced by people of all ages. These conditions can have a huge impact on your quality of life. Luckily, there is help available. A full diagnostic balance assessment can help you understand the root causes of your dizziness and give directions for treatment.
Comprehensive balance tests are made up of a number of subtests and are usually undertaken by your trusted, local Audiologist or Ear, Nose and Throat Specialist (ENT).
Why are balance tests necessary?
There are many causes of dizziness or vertigo and it can be difficult to find the underlying cause. It is important to remember that the balance system involves the ears, eyes and sensory receptors all working together co-ordinated by the brain and nervous system. Medications, anxiety and dehydration can affect this delicate balance. In many cases, there is a weakness in more than one area.
Some conditions will need to be tested for and eliminated in order to make the correct diagnosis. Therefore, a series of investigations are needed to provide helpful answers and determine suitable management strategies.
What are the types of dizziness?
Before choosing a treatment approach, the sensation of dizziness you are experiencing will need to be defined more precisely.
There are four types of dizziness:
Probably the most difficult to describe feeling of dizziness. Often caused by anxiety or hyperventilation.
Syncope or presyncope
The loss of consciousness or feeling as if you’re going to faint. Could be associated with an underlying heart or circulation problem.
Vision appears wobbly or out of sync with your movements. This can be due to inner ear disorders, neurological conditions, migraines or some medications.
Room or self-spinning
This rotational vertigo is often accompanied by nausea and vomiting. This is usually, but not always due to a problem with the balance system in the inner ear. Sometimes the eyes can be seen moving as they respond to the signals from the ear telling them that the room is spinning.
Understanding the balance system
To function, our brain and nervous system normally have to co-ordinate information from our ears, eyes, joints and skin receptors. If one or more parts of this system are damaged, we may experience balance problems.
The system adapts well to changes but this can take time. For example, when getting bifocal glasses for the first time some people feel off-balance for a few days or weeks until they become accustomed to them.
Each inner ear is filled with fluids called endolymph and perilymph. It consists of:
- The Cochlear which is responsible for hearing.
- The Utricle and Saccule. These contain calcium carbonate crystals called otoliths that respond to gravity so that we know which way up we are and are aware of any sudden movements, for example when an elevator stops.
- 3 semi-circular canals, each is set at right-angles to the others and fluid moving in each semi-circular canal tells the balance system the speed and direction of any rotational movements.
What happens when you feel dizzy?
When we turn or move our head we have an automatic reflex action that causes our eyes to move at the same speed in the opposite direction. This is called the vestibulo-ocular reflex. Audiologists use this reflex to help them assess balance function.
If there is a problem with the nerve pathways or brain function people often experience imbalance or vertigo, information from the rest of the body may not be processed and co-ordinated correctly.
There are several conditions affecting the inner ear that causes dizziness. This type of vertigo may be dysequilibrium or a sense of spinning, rotational vertigo. As the inner ear is involved a hearing loss and tinnitus are often associated with vertigo.
Problems with sensation sometimes seen in diabetics can reduce the input to the balance system and therefore make diabetics more prone to falling.
Full diagnostic balance assessments explained
There are many causes of dizziness and vertigo, initially, you will need to answer a series of questions and perform some simple movements to help the Doctor or Audiologist decide which investigations will be helpful. He or she will also need to know if you have a hearing loss, and about your general health and medications, you are taking.
As the inner ear is responsible for both hearing and balance, a hearing test is done to determine if there is a hearing loss. The hearing test will show the extent of the hearing loss and which sounds are affected by the hearing loss.
For example, if the hearing loss affects only the low-pitched tones on one side this may indicate a pressure build-up of fluid in the inner ear. This build-up of endolymphatic pressure is seen with Meniere’s Disease.
Meniere’s Disease is an unpleasant balance disorder that causes bouts of low-tone hearing loss, spinning vertigo, roaring tinnitus (noises in the ear), a feeling of ear fullness, nausea and vomiting. The low- tone hearing loss and tinnitus do fluctuate with this condition, so frequent hearing tests are recommended.
If the hearing tests indicate a high-tone hearing loss in one ear the hearing loss and vertigo could be due to damage to the nerves going to that ear. Some balance problems do not cause a hearing loss and normal hearing test results help eliminate some causes of vertigo.
The Hearing Test
The Audiologist will look in your ears before the hearing test. You will be asked to press a button when you hear tones of varying levels and pitch in each ear separately. This will be done in a sound-treated room or booth wearing headphones and then repeated wearing a special bone conduction headband.
Part of the hearing test is to assess speech discrimination; this involves listening to words and repeating them back to the audiologist.
Tympanometry is a test of the middle ear, sometimes people with vertigo complain of a feeling of fullness or pressure in their ear. The tympanometry hearing test can check that the middle ear is functioning correctly and is not blocked.
Together these hearing tests indicate which part of the ear or hearing pathway is causing a hearing loss. Regular hearing tests are often arranged to monitor hearing levels as fluctuations in hearing can help indicate the cause of any balance problems.
Monitoring hearing is helpful if people are being given medication that may cause hearing loss or balance problems, for example being treated for malaria or on chemotherapy for cancer. A hearing test may show early signs of inner ear damage before the hearing loss or imbalance becomes permanent.
This is a test for Benign Paroxysmal Positional Vertigo (BPPV), this is the most common cause of vertigo and over 2 per cent of Australians will experience this at some time. It is more common in the elderly and in those with another associated balance disorder, such as Meniere’s Disease.
The calcium carbonate crystals (otoliths) move from the Utricle, where they belong and float or sit in one of the semi-circular canals. This is almost always the posterior semi-circular canal. When the person turns over in bed or looks up in the affected direction the movement of the crystals in the fluid causes strong stimulation of the balance system.
Until the person moves out of this position or for up to 3 minutes the room appears to spin. Although not of great medical concern this condition can his can be quite frightening and disabling. The Dix-Hallpike test is a quick balance assessment that can be done without the aid of expensive equipment.
You will be asked to look towards the corner of the room and asked to lie back on the examination bed so that your head is below the level of your shoulders. The Audiologist, Physiotherapist or GP doing this will assist you. Don’t worry they will speak louder if you have a hearing loss, keep your eyes open as they need to look at your eye-movements. The vestibulo-ocular reflex causes the eyes to respond to any stimulation of the balance system.
If your Dix-Hallpike test is positive and you do have a posterior semi-circular canal Benign Paroxysmal Positional Vertigo (BPPV) this can be treated effectively with an Epley or other repositioning manoeuvre. These repositioning manoeuvres involve some simple movements to relocate the crystals back into the Utricle. If you are unable to perform these manoeuvres you may be given some other exercises to treat this.
As BPPV often occurs alongside other balance disorders, it is wise to have a hearing test and balance assessment if you still experience symptoms.
Tests of eye movement and co-ordination
As vision is an important part of co-ordination and balance, the Audiologist uses a camera to record eye movements. You will be asked not to wear eye make-up as the camera uses the darkness of your pupils to find the centre of your eyes. Mascara or eyeliner confuse the cameras.
You will be asked to follow lights moving around in front of you and the speed and accuracy of your eye movements will be recorded. This looks at the neural pathways involved with vision.
You will then be asked to stare at a point on the wall and your eyes will be covered. The camera uses infra-red technology so the audiologist will still be able to record eye movements in the dark. This part of the test can measure any ongoing vertigo and can be used to monitor your recovery.
Video Head Impulse Test (vHIT)
The vestibulo-ocular reflex causes a reflex action that moves the eyes in the opposite direction to head movements. This keeps our visual field stable, so the world does not bounce around as we walk or turn.
You will be asked to wear special goggles and the Audiologist will repeatedly turn your head in the direction of each of the 6 semi-circular canals whilst recording your eye movements. vHIT tests the function of each semi-circular canal separately.
This is a good test for detecting weakness in balance function on one side. Again, you will be wearing blacked-out goggles as the eyes provide the Audiologist with a “window to the balance system”.
You will be asked to lie almost flat on the bed and cool and warm air will be blown into each ear separately. It is normal to experience a spinning (rotational) vertigo that lasts 2-3 minutes after each irrigation. The test is done with the blindfold on, but you need to keep your eyes open so the Audiologist can record vertigo with the infra-red cameras. The Audiologist will then compare the dizziness for left and right irrigations to see if there is a difference.
The Audiologist will ask you to perform mental alerting tasks, such as naming animals, to keep your mind busy. They will have a copy of your hearing test so will speak louder for people with a hearing loss.
Your ears need to be free of wax for this test. The hearing test includes tympanometry, so the Audiologist can check that both middle ears are normal and therefore each inner ear gets the same stimulation.
This test can also be done using warm and cool water to irrigate. If you have no responses to the warm and cool water the Audiologist may use ice-cold water to see if there is any balance function on that side.
Note: You feel dizzy because the inner ear has been temporarily warmed or cooled down, causing a movement of the inner ear fluids. As the body gets back to normal body temperature vertigo will stop, so the test does not provoke an attack of vertigo. People with migraine-related vertigo may have stronger responses than normal.
Vestibular Evoked Myogenic Potentials (VEMPs)
We have automatic reflex actions that control eye muscles and also neck muscles. The Audiologist uses these muscle contractions to test the Utricle and Saccular function. The Utricle and Saccule are sensitive to gravity.
To test Saccular function electrodes are taped onto the neck muscles and you will be asked to tense these muscles as loud clicks or tones are played into your ears for a short time. The sound pressure stimulates the Saccule in the inner ear.
Testing Utricle function is similar, but electrodes are placed below the eyes.
Some people can be overly sensitive to loud sounds because of a condition called superior semi-circular canal dehiscence (SSCD). This is due to a thinning of the bony area protecting the superior semi-circular canal. Loud sounds or lifting heavy objects can cause sudden severe momentary vertigo.
This test is good at detecting SSCD, a CT Scan is usually arranged to confirm this.
Because sound pressure causes the response it can be done on people who are hearing test shows they have a profound hearing loss.
Electrocochleography (ECochG) is an objective technique that records the electrical responses of the inner ear to clicks. A repetitive clicking sound is played into each ear and the inner ears’ response to the clicks is recorded. Because the response happens immediately after each click the equipment can identify the ears responses from other neurological activity. Most clinics now use tip-trodes to record the responses, these are earplugs coated in a gold foil.
Meniere’s Disease causes episodes of spinning vertigo, roaring sounds in the ear and a fluctuating hearing loss. If the hearing test shows a severe or profound hearing loss you may not be able to have this test as you need to hear the clicks clearly.
With Meniere’s Disease, the responses are altered. ECochG is, therefore, a useful tool when Menieres Disease is suspected.
A few clinics have a specially designed Rotating Chair. You need to wear goggles so your eye movements can be recorded as the chair is spun or rocked at known speeds.
The rotating chair is particularly useful for detecting an absence of balance function and for testing children. The child does not need to follow complex instructions and can be sat on his/her parents’ knee for testing.
Imaging and Blood Tests
Blood tests, CT and MRI scans can also be helpful and depending on your symptoms may be arranged by your doctor. It is normal to have a scan if a hearing test shows you have more hearing loss in one ear than the other.
Where can you get help?
Attune Audiology Clinics have Audiologists that work closely with Ear, Nose and Throat Specialists and are experienced in balance and hearing testing.
The first step is to get a referral for a hearing test, an Audiologist will be able to advise you which tests will be useful.