Vertigo is a sensation of spinning or feeling that the world around you is moving, even when you are still. This feeling differs from general dizziness, which might involve lightheadedness or unsteadiness. When experiencing persistent or recurring episodes of vertigo, identifying its underlying cause becomes important. Healthcare professionals rely on specific evaluations, known as balance tests, to determine the source of this disorienting sensation. These tests pinpoint malfunctions within the body’s balance system.
What is a Balance Test for Vertigo?
Balance tests for vertigo encompass a series of assessments designed to evaluate the vestibular system. This intricate system, located within the inner ear and connected to the brain, plays a central role in controlling balance, spatial orientation, and coordinating movement. The purpose of these tests is to identify where the balance system is not functioning correctly, helping determine the specific cause of vertigo. By providing objective measurements, these tests guide healthcare providers to an accurate diagnosis, essential for an effective management plan.
Types of Balance Tests
Several types of balance tests are used to assess the vestibular system and diagnose vertigo. Each test offers unique insights into different components of the balance mechanism.
Videonystagmography (VNG) or Electronystagmography (ENG)
Videonystagmography (VNG) or Electronystagmography (ENG) tests measure eye movements to evaluate the inner ear and its connections to the brain. These tests often involve tasks like tracking moving lights, changing head and body positions, and caloric irrigation (introducing warm or cool air or water into the ear canal). Involuntary eye movements, called nystagmus, are recorded and analyzed to detect abnormalities indicating inner ear or central nervous system issues.
Posturography
Posturography, also known as computerized dynamic posturography (CDP), assesses an individual’s ability to maintain balance under various conditions. During this test, the patient stands on a specialized platform that can be stable or unstable, sometimes with moving visual surroundings. This evaluates how the brain utilizes information from vision, the vestibular system, and somatosensory input (sensations from muscles and joints) to maintain an upright posture. The test identifies specific balance deficits.
The Rotary Chair Test
The Rotary Chair Test evaluates the coordinated function between the inner ear and eyes as they respond to controlled rotational movements. The patient sits in a motorized chair in a darkened room, and special goggles record eye movements as the chair rotates at different speeds and directions. This assessment provides information about both inner ears and the central vestibular pathways, helping to differentiate between unilateral and bilateral vestibular issues.
Vestibular Evoked Myogenic Potentials (VEMPs)
Vestibular Evoked Myogenic Potentials (VEMPs) measure sound-evoked muscle responses. These responses assess the function of specific inner ear structures: the saccule and utricle, which detect linear acceleration and gravity. Two main types exist: cervical VEMPs (cVEMPs) measure neck muscle responses, and ocular VEMPs (oVEMPs) measure eye muscle responses. These tests provide information about the integrity of these otolithic organs and their associated neural pathways.
Preparing For and Undergoing the Tests
Preparing for balance tests involves several steps to ensure accurate results and patient comfort. Patients are advised to avoid certain medications, such as sedatives or tranquilizers, before the tests, as these can affect balance and eye movements. Avoiding caffeine, alcohol, and heavy meals on the day of the test is also recommended. Wearing comfortable clothing and refraining from eye makeup, especially for VNG/ENG tests that use goggles, can be helpful.
During the testing session, patients can expect assessments that may last from 30 minutes to a few hours, depending on the number of tests performed. The environment might include a dark room for some tests to better observe eye movements. Patients will generally be asked to sit or lie on an examination table or in a specialized chair, and sensors or electrodes may be placed on the head, face, or neck to record responses. Some tests, like caloric irrigation, might induce temporary dizziness, warmth, or cold sensations, but these are typically brief and closely monitored. The procedures are designed to be safe, with safety harnesses often used during posturography to prevent falls.
Understanding Test Results and Next Steps
The results from balance tests are not a standalone diagnosis but provide objective data about the function of the balance system. A healthcare professional, often an audiologist or an ENT (Ear, Nose, and Throat) specialist, interprets these findings. They consider the combined results from all performed tests alongside the patient’s detailed medical history, reported symptoms, and a physical examination. This comprehensive approach allows for a precise understanding of the balance disorder.
Based on this thorough evaluation, a specific diagnosis can be made, leading to a personalized treatment plan. Treatment strategies for vertigo can vary widely and may include medication to manage symptoms, vestibular rehabilitation therapy (VRT) involving specific exercises, or lifestyle adjustments. The goal is to address the identified issue effectively and help the individual regain stability and reduce vertigo episodes.