What to Expect.

Vestibular testing can take up to 3 hours. This doesn’t include a hearing test which is an additional 45 mins. This is a long appointment and we will take regular breaks. Each test is unique and depending on the reason for your referral, the tests performed can change. Below is an outline of the tests which can be performed during your appointment. First, we need to be prepared:

Preparation.

WAX

Please ensure your ear/s are free from wax before your appointment. Having lose or impacted wax can affect hearing results, make viewing the ear canal and ear structures difficult and a full and thorough assessment of your vestibular pathways difficult. Retesting maybe required in these circumstances.

MEDICATION

It is preferred that you are not on ‘dizziness’ reducing medication when you are assessed. Medications that reduce your symptoms can diminish test results. This is a decision that must be made in conjunction with your referring doctor. Ideally, it is preferred that 24 hours prior to your appointment, these medications are halted temporarily. * See Bithermal Calorics.

MAKE-UP

Please ensure that no make-up is worn to the appointment. Goggles with cameras are fitted to your face to view your eyes during these appointments. Any eye and facial makeup can affect results. Please ensure it is not worn to your vestibular appointment.

NECK CHECK

If you're experiencing neck issues, whether muscle-related or due to an injury, it's important to inform the Audiologist, as certain tests may need to be adjusted or skipped entirely.

VESTIBULAR TESTS.

vHIT - Video Head Impulse Test

The vHIT tests your ability to match rapid head movements with equal and opposite eye movements. Our inner ear balance organs stabilise the visible world upon the retina as we move our heads during walking and running. This is achieved by the vestibulocular reflex (VOR), by means of connections between the balance organs and the extraocular muscles which move the eye.
Method
You will be asked to sit upright and wear a pair of lightweight video-glasses which are fitted tightly to the head. You will focus upon a fixed target. The audiologist will deliver ~20 head turns in the direction of each semicircular canal. The speed of eye movement is measured and expressed as a fraction of the speed of head movement. This test is a valuable screening test of semicircular canal function.

Vestibular Myogenic Evoked Potentials - VEMP

The gravity sensors of our inner ear balance organs have retained their primitive ability to be activated by sound and vibration. The VEMP test exploits this sound and vibration sensitivity to assess the integrity of our gravity sensors.
Method
Surface electrodes (like in an ECG test) will be applied to the skin directly under your lower eyelids (oVEMP) and over your neck muscles (cVEMP). You will be asked to look upwards & to elevate your head from lying down. You will be asked to listen to clicking noises through headphones. The recordings taken from your neck muscles or eye muscles give us useful information about your vestibular organs, the Utricle and Saccule.

Video Nystagmography (VNG).

This series of tests assesses your ability to maintain eye stability on moving visual stimuli, differentiating where on the vestibular pathway an impairment, if any, exists. While either sitting or lying down on a bed, camera goggles will be placed on your eyes and a small infrared camera records your eye movements. You will be presented with visual stimuli which you need to track with your eyes. These tests are carried out with a large TV in a darkened room. A subtest includes the Dix-Hallpike positional test where you are lay down rapidly with your head hanging off the bed (with support from the tester). Those with certain conditions may find this test induces dizziness but all other VNG tests should not evoke this sensation.

Bithermal Calorics.

While lying semi reclined on a bed, camera goggles will be placed on your eyes and a small infrared camera records your eye movements. The test involves irrigating the external ear canal with warm and cool water for 40 seconds; you will experience a sensation of tilting or turning as your balance organs are stimulated by the water. You may also notice your eyes flicking in response to the stimulus (nystagmus). The velocity of these eye movements is recorded and compared for left and right ear stimulation. It is important to keep your eyes open and to remain alert during the test. The Audiologist who performs the test is skilled and will ensure that you feel safe and comfortable during the test. They may also engage you in conversation to ensure you stay awake. This test is designed to make you feel dizzy for a short period of time.

Preparation

You will need to ensure there is no wax in your ears, and there are no perforations in your ear drums ( a tymp test will be performed beforehand to ensure). It is ideal to not eat or drink for 4 hours before the test. Medications specifically taken to diminish an attack of vertigo such as prochlorperazine ("stemetil") or Cinnarizine ("stugeron") should be withheld for 48 hours before the test. Please speak to your doctor to check if these can be withdrawn. All other medications including migraine prevention drugs, pain killers and cardiac medications should be taken with a sip of water, on-time as prescribed.

Electrocochleography.

This test measures the distortion of inner ear membranes (linings) caused by the presence of excess inner ear fluid. It is useful in the diagnosis of Meniere's Disease and related disorders.

The test involves placing a thin electrode (TM trode) down the ear canal and resting it on a safe place on the ear drum. During the test, noises (clicks or tones of specific frequencies) are presented through headphones. Some small discomfort is felt during this test when the electrode is placed. If this test can’t be fully completed with a TM Trode for anatomical reasons, a gold foil insert electrode is used in the ear canal only.

Auditory Brainstem Response.

This is an extension of the standard hearing test and further measures the auditory nerve from the ear (cochlea organ) to the brain. It is a non-invasive test, generally used to diagnose hearing nerve issues, or myeline sheath abnormalities, such as MS. It can also be used for those unable to participate in a regular hearing test. such as children or those suffering an impairment.
Method
The audiologist will first cleanse the skin on the forehead and ears and will place very small recordings electrodes (similar to ECG) onto the head and behind the ear. Then the patient lies comfortably on a bed with their eyes closed, in a darkened room, as clicking sounds are played for about 5 minutes into each ear separately. The recording electrodes measure brain activity which help to determine how the brain is hearing and processing the sounds, and so there is no response needed from the patient.