Additional audiology test introduced to diagnose vertigo and balance problems
People who experience dizziness, vertigo and balance problems are now benefiting from an additional diagnostic test that has been introduced in the JGH Audiology Department, one of the few audiology services in Quebec where this kind of evaluation is performed.
Known as VNG (videonystagmography), this assessment is one component in a group of tests whose depth and detail have made diagnosis more accurate than ever.
Lending further effectiveness to the process is that audiologists are playing a greater role in interpreting the results of the VNG and related tests, and then relaying or discussing the data with a designated physician in the JGH Department of Otolaryngology-Head and Neck Surgery.
“Since Audiology is now capable of providing the physician with a more comprehensive look at what the patient is experiencing, the quality of the resulting diagnosis and treatment is also improved,” says Gina Mills, Director of the Department of Audiology and Speech Pathology.
Despite what the word “audiology” suggests, the field involves more than measuring hearing. Often, the patient’s balance is evaluated, with particular attention to the vestibular system, the portion of the inner ear that contributes to the sense of balance and spatial orientation.
According to Audiologist Voula Tsagaroulis, another key tool is the VEMP (vestibular evoked myogenic potentials) test, which the JGH has been using since 2015 to measure part of the vestibular system and the vestibular nerve.
In addition, since last year, the battery of tests in the Audiology Department has included the VNG, in which part of the test involves placing video goggles over the patient’s eyes, and introducing air into the patient’s ears. (The VNG has replaced a less sophisticated test in which electrodes were affixed to the patient’s head.)
Audiology and Otolaryngology have agreed that it would be beneficial to have vestibular testing conducted by audiologists who help interpret the results, rather than by technicians who delivered raw data without interpretation.
“It’s a real asset to have audiologists not only conducting the balance testing, but helping in understanding the patient’s problems,” says Dr. Jamie Rappaport, Chief of Otology and Neurotology in the JGH Department of Otolaryngology-Head and Neck Surgery.
“The audiologists know what they’re looking for and, if necessary, they can adapt a test on the fly. If a result isn’t clear, they can also make the necessary adjustments or do a bit of extra testing while the patient is still in the examining room.
“I do a separate evaluation of the data and, given the audiologists’ expertise, I usually corroborate their interpretation. Since the audiologists’ reports are so comprehensive and readable, they’re of great help when I review the information with the patient, and when I discuss the data with residents and medical students.”
Possibly on the horizon is yet another test, the vHIT (video Head Impulse Test). According to Ms. Tsagaroulis, the VNG can measure what is happening in only one of the three semi-circular canals in the vestibular system, whereas the vHIT covers all three canals separately. However, Ms. Mills says funding must still be found before her department can acquire the vHIT.
Even so, Ms. Mills notes, patients are currently being assessed with unprecedented accuracy, while reaping the benefits of inter-disciplinary teamwork. “We take great pride in what we do, but we’re always on the lookout for even better ways to serve our patients.”