Dizziness is one of the more common reasons adults consult their doctors. Dizziness is a term used to describe a range of sensations, such as feeling faint, lightheaded, wobbly or unsteady. In some balance disorders, the patient may not experience any unusual sensation, but balance cannot be maintained. Dizziness that generates a false sense that you or your surroundings are rotating or moving is called vertigo. It can also be accompanied by other symptoms like nausea, vomiting, hearing loss, a sensation of pressure in the ears, or noises in the ears called tinnitus. When you think about balance function, the part the ears play might not immediately spring to mind. The ears however are essential in maintaining balance. The nerve which sends signals to the brain from the inner ear balance system also controls hearing function. The ears however are not the only system which helps us balance. Ears, eyes, joints, nerves and muscles all work together in unison to keep us upright and balanced. If any part of this system is faulty or disturbed, the brain is unable to put all the information together, this may result in vertigo or unsteadiness. Dizziness can be a symptom of a range of health conditions, which makes it a challenge for a doctor to diagnose the underlying cause.
BALANCE TESTING -why?
Diagnosing the underlying cause of dizziness can be complex and the process usually requires several tests. In some cases, a doctor or specialist will refer you to an audiologist who can carry out testing to find out which parts of your hearing and balance system are working correctly and which ones are defective. Balance testing takes about an hour and a half to two hours. The audiologist will start by taking a medical history. The more specific a patient can be about when the dizziness began, when episodes are most likely to happen and what sensations are experienced: the more information the audiologist or ENT specialist will have to accurately diagnose the cause. The balance system is situated primarily in the inner ear which means that hearing loss can commonly co-exist with balance disorders. A hearing test is therefore a common diagnostic procedure and is part of the balance test battery, as is the recording and testing of eye movements.
WHAT IS INVOLVED IN THE BALANCE TESTING?
THE HEARING TEST
Hearing testing is important for dizzy and off-balance patients because small unnoticed hearing changes can show inner ear damage or other medical problems. Hearing disorders can also co-exist with the dizziness as part of one condition. The hearing test consists of four parts, a graph of hearing sensitivity called a Pure Tone Audiogram, a hearing test involving discriminating speech called Speech Audiometry, Tympanometry (a test of middle ear function) and a test of hearing reflexes.
Pure Tone Audiometry
This is a hearing test to find the quietest sounds that an individual can hear. Different sounds are presented through earphones or a headband. The patient is asked to respond to the sounds by pressing a button when they hear them. Pure tone audiometry is the main hearing test used to identify hearing levels, enabling identification of the degree, type and configuration of a hearing loss and thus providing a basis for diagnosis and management of the hearing loss. Pure-tone audiometry provides hearing levels for each individual ear and uses frequency specific pure tones, so that the configuration of a hearing loss can be identified.
Speech Audiometry
This is a hearing test to check how well you can hear speech sounds. Words are presented to each ear in turn through earphones and the patient is asked to repeat what they hear. The words are presented at medium, loud and quiet levels. The number of correctly heard speech sounds is recorded. Speech audiometry is a fundamental tool in hearing loss assessment. Together with pure-tone audiometry, it can aid in determining the degree and type of hearing loss. Speech audiometry provides information on word recognition and about discomfort or tolerance to speech stimuli.
Tympanometry
This involves a soft tipped probe which is placed in the ear canal and pressure changes show how the eardrum and middle ear are working. A graph is generated which can be interpreted by the audiologist. Tympanometry can help diagnose disorders that can lead to hearing loss.
Acoustic Reflex Threshold
Short bursts of sound are presented through a soft tipped probe placed in your ear canal to check the working of the small, middle ear muscles and the nerve pathway that innervates this reflex.
An audiologist can evaluate the pattern of hearing loss from these four hearing tests and this pattern can give a significant amount of information about the hearing system, the results of which frequently correspond with the results of balance testing, thus aiding more accurate identification of the disorder.
BALANCE TESTS
Electrocochleography This is a technique of recording electrical responses generated in the inner ear and auditory nerve in response to sound stimulation, using an electrode placed in the ear canal. This hearing test is used to detect elevated inner ear pressure or for the testing and monitoring of auditory nerve function.
Video Head Impulse test (vHIT). The video Head Impulse Test (vHIT) incorporates a new technology that uses a high speed, lightweight video goggles to record corrective eye movements in patients with impaired inner ear function. It provides a quick and objective measure of the function of the six balance canals of the inner ear balance canals in response to a range of natural daily head movements. During a vHIT test the patient wears goggles that record eye movements, while the audiologist moves the patient’s head in small but quick movements.
Vestibular evoked myogenic potentials (VEMP) test. This hearing test measures how certain muscles respond in reaction to sound. It can show if there is a problem in the inner ear hearing and balance mechanism. During this test the patient will have an earphone in their ear. Sensor pads will be attached to the neck, forehead, and under your eyes. These pads will record your muscle movements. Clicks and/or bursts of tones will be sent to the earphone. While the sound is playing, the patient is asked to turn or lift the head or eyes for short periods of time.
Electronystagmography (ENG) and Videonystagmography (VNG) tests. These tests record and measure eye movements. This test measures the reflex that is initiated by the inner ear but controls eye movement. During the test the patient will be asked to sit or lie on an examination bed in a darkened room. The patient is asked to look at and follow patterns of light on a screen. Another part of the test, the Caloric test involves introducing warm and cool air into each ear separately. This should cause the eyes to move in specific ways and allows the audiologist to compare how well the two balance organs are working and to understand whether the dizziness may be caused by one of the balance organs not working as well as the other. These patterns of eye movement are recorded by small cameras housed in a pair of goggles and are transmitted to a computer. The audiologist can see these recorded eye movements and can measure and analyse the responses.
Dix Hallpike Manoeuver This test measures how a patient’s eyes react to abrupt changes in body. During this test the audiologist will move the patient quickly from sitting to lying down position and/or move the head in different positions. They will check eye movements to see if there is evidence of a false sense of motion or spinning. If the test is positive, the patient will experience a sensation of movement and will develop a pattern or repetitive eye movement called nystagmus. The audiologist can determine which ear and which canal in the balance organ is involved and treatment depends on this critical information.
WHAT WILL BE THE RESULT OF THE TESTING?
A doctor or Ear, Nose and Throat consultant may order some or all these tests and others depending on the history and symptoms. Each test contributes distinct and valuable information to your overall diagnostic picture, which may not be available through other means. Based on the results of your hearing test and balance tests, the audiologist will send a report to your referring specialist. The results will assist your specialist to arrive at a diagnosis. In some cases, accurate diagnosis will require further hearing tests, or other diagnostic tests such as magnetic resonance imaging (MRI). Once a diagnosis is determined, a range of effective and safe treatments is determined to control most of the conditions underlying dizziness. Some conditions can be managed with medication or diet and some can be treated with special ‘’manoeuvers’’ which involve simple movements of the head and body. Others require surgical intervention and physical therapy. Hearing loss can be managed with the use of hearing aids and hearing implants. If you are experiencing vertigo or imbalance, ask your doctor to refer you to a specialist audiologist for a balance assessment to aid with accurate diagnosis of your condition and with finding appropriate and timely treatment.
Call 1300 736 702 to book a comprehensive hearing test with one of Attune Hearing’s qualified audiologists. As a medical audiology company, we’re proud to offer HICAPS and Medicare. Our holistic tests run for 45 minutes - 1 hour, allowing our qualified audiologists to test the entire hearing system.