Contributed by Debbie Clason, staff writer, Healthy Hearing
Hearing health researchers believe a MRI magnet may eventually help diagnose and treat individuals afflicted with balance disorders and dizziness based on findings from two recent studies.
In 2011, Johns Hopkins researchers discovered the strong pull of a MRI’s magnetic field pushes on the fluid in the inner ear, causing individuals affected with balance disorders and dizziness caused by inner ear issues to have jerky eye movements and dizziness.
Two new studies suggest these strong magnets may eventually be able to diagnose, treat and study inner ear disorders. This is significant because current testing can be uncomfortable and invasive.
In the first study, a team led by Brian Ward, M.D., a resident in the Department of Otolaryngology-Head and Neck Surgery at Johns Hopkins School of Medicine, studied the eye movements of nine patients with balance disorders. They discovered these individuals displayed different eye movements depending on which ear was affected when they were placed in the MRI tunnel. The results were published online on March 13, 2014 in the journal Frontiers in Neurology.
In the second study, Dr. Ward and his team studied the effects of the MRI magnet on zebrafish, which have anatomical vestibular systems similar to humans. These healthy zebrafish displayed the same vertigo and imbalance characteristics when exposed to the magnets as humans with inner ear issues displayed in the first study. Dr. Ward believes the findings could lead to useful ways to harness the effect of a MRI magnet on the inner ear. These findings were published March 19, 2014 in the journal PLOS One.
What is a balance disorder?
A balance disorder is a condition that makes you feel dizzy or unsteady on your feet.
According to the National Institute on Deafness and Other Communication Disorders (NIDCD), approximately four out of every 10 people will experience an episode of dizziness significant enough to send them to the doctor at some time in their life.
Symptoms of a balance disorder may include feelings of vertigo or a spinning sensation, falling or the sensation you might fall, feeling lightheaded or faint, having blurred vision, or being confused and disoriented.
What causes balance disorders?
Balance disorders may be caused by medications you are taking, an injury to the head, or problems with the inner ear or brain.
If you believe you, or a loved one, may have a balance disorder, consult with your family physician. They may refer you to an ear, nose and throat (ENT) physician or audiologist who conducts balance testing.
Depending on your medical history and results of a physical examination, the ENT or audiologist may perform the following tests to determine if you have a balance disorder:
- Electronystagmography (ENT): A battery of tests that measure involuntary and other eye movements. Tests include recording eye movements as they follow a moving target, while the head is positioned in different positions, and how eye movements react to temperature change by circulating warm or cold water in the ear canal.
- Rotation tests to evaluate how well the eyes and inner ear work together.
- Vestibular Evoked Myogenic Potential (VEMP): a test to determine whether the saccule (sensory cells in the inner ear) and vestibular nerve are intact and functioning properly.
- Computerized Dynamic Posturography (CDP): a test to determine motor control and balance function in different environments.
- Hearing tests, including pure tone and speech audiometry, tympanometry, acoustic reflex, electrocochleography, otoacoustic emissions and auditory brainstem response.
- Scans, including MRI and/or CT.
- Other tests, including blood work and allergy testing to rule out causes unrelated to your vestibular system.