Diagnostic Testing

When you experience dizziness or balance problems that affect your sense of motion, we always consider the vestibular system. The vestibular system is responsible for detecting and processing movement, and when it isn’t functioning properly, it can cause a variety of symptoms. Dizziness or motion issues can present in different ways. Some people experience motion intolerance, where moving their head, eyes, neck, or body makes them feel unwell. Others have visual motion sensitivity, where looking at busy patterns, screens, or passing cars triggers dizziness or nausea. Some people feel a false sense of motion, such as rocking, spinning, tilting, swaying, floating, or even a sensation of disconnection from their body or surroundings. Any of these motion-related symptoms can originate from the vestibular system.

The vestibular system has two main components. The peripheral vestibular system, located in the inner ear, contains tiny organs that detect motion, including gravity and head rotation. The central vestibular system consists of the brain structures that process this motion information. The inner ear detects movement, while the brain interprets it to help you maintain balance. However, because these two systems are closely linked and work together, a problem in one, the other, or both can cause the same dizziness symptoms. This makes it difficult to determine the exact source of dizziness based on symptoms alone.

To better understand what is causing your dizziness, we recommend vestibular function testing as part of your evaluation. These tests help us determine how well your inner ear detects motion and how effectively your brain processes this information. By identifying the specific source of dysfunction, we can develop a more precise treatment plan tailored to your needs. Vestibular function testing is generally well tolerated, but if you are particularly motion-sensitive or anxious about testing, our audiologists will take a gentle approach to ensure you remain as comfortable as possible. The specific tests recommended before your evaluation include Video Nystagmography (VNG), Video Head Impulse Testing (vHIT), Vestibular Evoked Myogenic Potentials (VEMPs), and an audiogram to assess inner ear function comprehensively. Understanding how your vestibular system is functioning is the first step toward effective treatment and improving your quality of life.

Background
The Video Head Impulse Test (vHIT) is a diagnostic test that evaluates the function of the vestibulo-ocular reflex (VOR), which stabilizes vision during head movement. It helps identify dysfunction of the semicircular canals in the inner ear, which can contribute to dizziness and imbalance.

How It Works
During the test, the patient wears lightweight goggles equipped with a high-speed camera that tracks eye movements. The examiner rapidly moves the patient’s head in different directions while the system records how well the eyes compensate for these movements.

What It Diagnoses
vHIT is used to assess vestibular hypofunction, including conditions such as vestibular neuritis, bilateral vestibular loss, and chronic dizziness. It helps determine whether the inner ear is properly sending balance information to the brain.

Preparation & What to Expect
No special preparation is required. The test is quick, non-invasive, and does not cause significant discomfort. Patients may briefly feel dizzy during head movements, but this subsides quickly.

Background
Vestibular Evoked Myogenic Potentials (VEMPs) are tests that evaluate the function of the otolith organs in the inner ear, which help detect head position and movement. There are two types:

• Cervical VEMP (cVEMP): Tests the saccule and its connection to the neck muscles.
• Ocular VEMP (oVEMP): Tests the utricle and its connection to the eye muscles.

How It Works
Small electrodes are placed on the neck (for cVEMP) or under the eyes (for oVEMP). The patient listens to clicking sounds or tones through earphones while the system records muscle responses to detect inner ear function.

What It Diagnoses
VEMPs help diagnose conditions such as Superior Canal Dehiscence Syndrome (SCDS), Meniere’s Disease, and vestibular neuritis by assessing otolith organ function.

Preparation & What to Expect
Minimal preparation is needed. The test is painless, though some patients may experience mild discomfort from the sounds. It is non-invasive and typically takes about 30 minutes.

Background
Video Nystagmography (VNG) is a test that evaluates eye movements to assess vestibular (inner ear) and neurological function. It measures involuntary eye movements (nystagmus) that can indicate balance disorders.

How It Works
The patient wears special goggles that record eye movements while performing different tasks, such as following visual targets, lying in different positions. If someone has a history of Meneire's Disease, it is recommended to perform calorics (inner ear stimulation with air blown in the air). Calorics is not recommended if you have significant motion sickness, migraines or concussion history. 

What It Diagnoses
VNG helps diagnose vestibular disorders such as BPPV, Meniere’s Disease, vestibular neuritis, and central nervous system conditions affecting balance.

Preparation & What to Expect
Patients may need to avoid certain medications, caffeine, and alcohol before testing. Some parts of the test may cause brief dizziness, but it is generally well tolerated.

Background
Caloric testing can be added to the VNG test and assesses how well each inner ear responds to temperature changes, which affect the vestibular system’s function. It helps determine whether both ears contribute equally to balance.

How It Works
Warm and cool air or water is gently introduced into the ear canal while eye movements are recorded. The temperature change stimulates the inner ear, temporarily inducing dizziness and nystagmus.

What It Diagnoses
Caloric testing helps detect unilateral vestibular weakness caused by conditions such as vestibular neuritis, Meniere’s Disease, and chronic vestibular dysfunction.

Preparation & What to Expect
Patients may need to avoid certain medications before the test. The test can cause temporary dizziness, nausea, or imbalance, but symptoms resolve quickly. Calorics is not recommended if you have significant motion sickness, migraines or concussion history. 

Background
Computerized Dynamic Posturography (CDP) is a test that evaluates how well the body maintains balance under different standing conditions. It assesses the function of the inner ear, vision, and proprioception (body awareness) in maintaining stability.

How It Works
The patient stands on a moving platform inside a booth while wearing a safety harness. The platform and surrounding visual scene may shift to test how the body responds to balance challenges.

What It Diagnoses
CDP helps assess balance dysfunction in conditions such as bilateral vestibular loss, post-concussive dizziness, and neurological disorders affecting posture and coordination.

Preparation & What to Expect
No special preparation is needed. The test is safe, but some patients may feel unsteady when the platform moves. It typically takes about 30 minutes.

Background
Rotary Chair Testing assesses the function of the inner ear and its ability to stabilize vision during head movements. It is particularly useful for evaluating bilateral vestibular loss and chronic dizziness.

How It Works
The patient sits in a motorized chair in a dark room, wearing goggles that record eye movements. The chair rotates at different speeds while the system measures how the eyes respond to movement.

What It Diagnoses
This test helps diagnose bilateral vestibular hypofunction, vestibular neuritis, and central nervous system conditions affecting balance.

Preparation & What to Expect
Patients should avoid sedating medications before testing. Some dizziness may occur during the test, but it is brief and well tolerated.

Background
Tilt Table Testing is used to evaluate blood pressure and heart rate responses to changes in posture. It is commonly used for diagnosing conditions that cause dizziness or fainting related to blood circulation.

How It Works
The patient lies on a table that gradually tilts from a horizontal to an upright position while heart rate and blood pressure are monitored. The test assesses how the autonomic nervous system controls circulation in response to gravity.

What It Diagnoses
Tilt Table Testing is used to diagnose conditions such as orthostatic hypotension, neurally mediated syncope, and dysautonomia.

Preparation & What to Expect
Patients may need to fast before testing and should avoid caffeine or certain medications. Some may feel lightheaded or faint during the test, but medical staff closely monitor responses.