People With Hearing Loss May Overestimate Ability to Balance

New research from Gallaudet’s Vestibular And Balance Lab indicates that people with hearing loss may not be able to accurately identify their own balance issues.

Deafness Balance

Balance is controlled by the vestibular system of the inner ear.

How does your body's balance system work?

There are three components of balance: the visual system, the proprioceptive system (your overall sensing of movement), and the delicate and complex vestibular system in your inner ear. The brain integrates and processes all the information from these three systems and sends it throughout our bodies, helping us maintain our balance or sense of equilibrium.

Researchers at Gallaudet’s Vestibular and Balance Lab asked patients with and without hearing loss (who self-identified as “deaf”) about their sense of balance. In general, both groups reported the same sense of balance.

But, vestibular function testing and activity-based balance tests revealed a significant difference in balance function between the two groups, with the hearing loss group performing significantly worse than the group with normal hearing.

The results of the study suggest that individuals with hearing loss may overestimate their own balance capabilities. Poor balance function may limit activity, and increase the individual’s risk for falling. Not being able to precisely assess these issues could put patients at risk, and the study highlights the need to rigorously assess the balance function of patients with hearing loss, so that appropriate referrals may be made.

How the research was performed

To evaluate how the self-reported data impacts deaf individuals, researchers looked at data from 57 adults between the ages of 18 to 29 years. Of them, 39 were deaf and 18 could hear.

During the investigation, patients shared a brief medical history. They completed what’s known as the activities-specific balance confidence scale, a self-reported rating of balance, and completed the Modified Clinical Test of Sensory Integration of Balance, among other measures.

While both groups said they had good or excellent balance, there were significant differences in actual vestibular function among the deaf people. Vestibular function controls our sense of balance, and it involves parts of the inner ear and the brain that process sensory information.

A relatively large subset of deaf participants experienced increased sway velocity (a measure of how a person is adjusting their position to maintain balance) during balance-function testing that required increased reliance on vestibular cues. This indicated that their balance was not as good as they had said it was.

Understanding the results: Perception vs. reality

One of the researchers, Chizuko Tamaki, AuD, PhD, a professor at Gallaudet University in Washington DC, told HearingTracker that she wasn’t sure why deaf individuals reported similar balance ability to those who can hear.

Chizuko Tamaki 1719x2048

Dr. Chizuko Tamaki. Photo courtesy Gallaudet University.

She suggested that it could be hard to be aware of it. “It is hard to be aware of something one doesn't have or never had,” Tamaki said.

“The vast majority of our subjects reported being congenitally deaf, and it is very possible that the vestibular impairment they presented was congenital as well,” she added.

Another possible explanation of this finding is that the patient may not feel like there is an impairment.

“Perhaps through their lifetime, they have developed ways to utilize other senses to allow them to perform balance tasks and never needed to feel they are imbalanced,” Tamaki explained.

Devin L. McCaslin, PhD, a professor of otolaryngology at University of Michigan Medical School, who was not involved in the research, echoed that sentiment.

Mccaslin Devin

Dr Devin L. McCaslin. Image courtesy University of Michigan.

He speculated that the deficits may have to do with their reference point. “If someone [with or without normal hearing] has an undiagnosed balance [issue] that is congenital or occurs early on in life then that becomes normal for the individual. They may just assume that their balance is just like everyone else’s.”

Putting the learning into practice

As a result of the findings, the researchers say healthcare providers should conduct a comprehensive discussion of balance and vestibular symptoms with patients who self-identify as deaf in order to ensure that the patient receives the appropriate screenings or referrals.

“What our study showed is that simply asking ‘How is your balance?’ is not sufficient for deaf people,” Chizuko Tamaki, AuD, a professor at Gallaudet University in Washington DC, told HearingTracker.

“If the answer is ‘bad,’ of course a follow-up will be needed, but even if the answer is ‘good,’ doctors should dig deeper,” she said.

To pick up on vestibular issues, healthcare professionals should ask about walking at night or in the dark, which will probably give a clearer understanding of their status. Also, having patients stand on a piece of foam with their eyes closed for 20 seconds can be a quick objective screening to identify those with vestibular deficits, Tamaki said.

“For people that experience dizziness or balance problems, accurate diagnosis and management are essential,” she added. There are many possible causes of those issues and ways to improve the situation.

McCaslin agrees that the study emphasizes the importance of screening. Since it showed that individuals with profound hearing loss, while not perceiving any deficits in their balance performance, have significant vestibular and balance impairments, he said, it’s important for medical professionals to intervene.

“The study suggests that healthcare professionals should be completing objective measures of balance in deaf individuals rather than relying solely on patient self-report,” he said. “Findings can also be extended to other individuals with hearing impairment, and we should work towards ensuring that we incorporate balance screening measures that are both sensitive and specific.”

The study also “makes the case for screening vestibular function in children at risk at an early age,” McCaslin added.

Physicians, physical therapists, and audiologists should be aware of potential risk factors associated with vestibular impairments in those with hearing impairment both at an early age and throughout the lifespan, he added.

Looking forward

Tamaki is interested in continuing her research, focusing on whether deaf individuals’ vestibular perception changes as they age.  Most people achieve the peak of physical functioning by age 30, and then a decline begins, she noted.

“My concern is that the deaf people with lifelong vestibular impairment who learned to effectively use other senses may start to have difficulties as vision, sensations in their feet and legs, and processing in the brain decline with age. This may catch them off guard,” Tamaki said. Obviously, these shifts could increase the risk of falling as these individuals age and are less able to maintain balance. This is an important area for researchers, healthcare professionals, and individuals with hearing loss—and their loved ones—to be aware of.