Videonystagmography (VNG) testing is a diagnostic procedure used to evaluate balance problems and dizziness. This non-invasive test objectively measures eye movements to identify underlying causes and understand the balance system’s function.
Understanding VNG Testing
VNG testing assesses the vestibular system, including parts of the inner ear and brain pathways for balance and spatial orientation. By recording eye movements, the test detects abnormalities in these intricately connected pathways, which coordinate stable vision during movement.
Healthcare providers recommend VNG testing for persistent dizziness, vertigo (a sensation of spinning), unsteadiness, or unexplained falls. The test helps pinpoint whether the issue stems from the inner ear, the brain’s processing of balance information, or a combination, guiding appropriate treatment.
Specialists Who Perform VNG Testing
Audiologists primarily perform and interpret VNG tests. These specialists are extensively trained in hearing and balance disorders. Their expertise allows them to conduct the various components of the VNG test and analyze the resulting data to assess vestibular system function. Audiologists often work closely with other medical specialists.
Otolaryngologists, commonly known as ENTs, frequently order VNG tests for their patients. These physicians specialize in conditions affecting the ear, including those that cause dizziness and balance issues. While ENTs diagnose and treat these conditions, they typically rely on audiologists to perform the technical aspects of the VNG test and provide initial interpretations. They then use these results to guide their medical or surgical interventions.
Neurologists also utilize VNG testing for patients with dizziness or balance complaints that may have a neurological origin. Neurologists focus on disorders of the brain, spinal cord, and nerves. They may order a VNG to differentiate between inner ear problems and central nervous system issues that can mimic vestibular dysfunction. These specialists often collaborate with audiologists to ensure accurate diagnosis and management.
Preparing for and Undergoing VNG Testing
Patients preparing for a VNG test receive specific instructions. Typically, individuals are advised to avoid certain medications, such as sedatives, antihistamines, and vertigo suppressants, for a period before the test. It is also recommended to refrain from consuming caffeine or alcohol and to avoid wearing eye makeup, which could interfere with the specialized goggles used during the procedure. These preparations help minimize external factors that might influence eye movements.
During the VNG test, the patient wears a pair of goggles equipped with infrared cameras that record eye movements. The test generally consists of several parts designed to evaluate different aspects of the vestibular system. These components include ocular motor tests, where the patient follows moving lights or targets, and positional tests, where the patient’s head and body are moved into various positions. Another common part is the caloric test, which involves introducing warm or cool air or water into each ear canal to stimulate the inner ear and observe the resulting eye movements.
The entire VNG procedure typically takes between 60 to 90 minutes to complete. Throughout the test, the audiologist or technician provides clear instructions and monitors the patient’s comfort. Some individuals may experience temporary dizziness or nausea during certain parts of the test, particularly during the caloric component, but these sensations usually subside quickly after the stimulation ceases. The data collected from these different maneuvers provides a comprehensive picture of the vestibular system’s responsiveness.
Where VNG Testing Takes Place
VNG testing is performed in specialized medical environments that house the necessary diagnostic equipment. Audiology clinics are common locations, as audiologists are the primary professionals conducting these evaluations. These clinics are equipped with dedicated VNG systems and trained staff.
ENT offices frequently have VNG testing capabilities, either directly within their practice or in conjunction with an attached audiology department. This allows for convenient referral and coordination between the diagnosing physician and the testing specialist. Neurology clinics and hospital balance centers also offer VNG testing as part of their comprehensive diagnostic services for patients with complex balance disorders.