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Living With Hearing Loss Unlocking the Key. Lina A.J. Reiss, Ph.D
hearing health foundation Unlocking the Key
After experiencing balance problems in her 40s, an Emerging Research Grants scientist discovers the cause of her childhood hearing loss. By Lina A.J. Reiss, Ph.D.
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I became interested in the fields of hearing research, biomedical engineering, and neuroscience in part from my own hearing loss. I have had a severe to profound hearing loss since early childhood. Diagnosed at age 2 ½ and fitted with powerful hearing aids, I learned to speak and listen only with intensive speech therapy. I am the only person with a hearing loss in my family, so we always thought the cause was due to illness or possibly ototoxic medications.
In my early 40s, I started having vestibular (balance) problems. It started in November 2018, when we took a big family fishing trip on the Amazon River in Brazil. It involved four flights each way, with the last leg a few hours in a small, unpressurized aircraft. On landing I felt a sensation of fullness and muffled hearing in my left ear that took several minutes to resolve, and a few days later, I noticed some mild imbalance walking around.
It was on the return trip when I again experienced problems with my left ear on landing. I was unable to walk straight in the airport, and head movements, especially nodding, caused disorientation.
Based on these symptoms, my otolaryngologist and colleague Yael Raz, M.D., and I thought I had benign paroxysmal positional vertigo (BPPV). A common vertigo triggered by movement, BPPV occurs more often with age and is attributed to calcium crystals that get dislodged and move more slowly than fluid through the inner ear’s semicircular canals. I did the recommended treatment for BPPV, the Epley maneuver, and symptoms gradually disappeared after a month.
More Flights, and Imbalance
In the months afterward, I had two other (unavoidable) cross-country flights that put the BPPV diagnosis in question. Now my vertigo was triggered by head nods as well as head turns—and then also head tilts. Walking around stairwells or turning my head to see someone’s face while walking was challenging. I started touching the wall at intervals to keep my balance.
Then a new vestibular symptom appeared. In response to loud sounds—especially low-frequency sounds like my husband’s voice—I felt the room start to spin slowly. While disconcerting, this indicated to me that my vestibular cells could now respond to sounds, which would normally only be detected by auditory hair cells.
We thought I had superior canal dehiscence (SCD),
discovered by Lloyd Minor, M.D., at Johns Hopkins University in the 1990s, coincidentally while I was a graduate student there. SCD is essentially a hole in the superior semicircular canal, leading to a “third window” (alternate pathway) for sound transmission through the vestibular system that would explain balance responses to sound.
This was worrying because SCD often gets worse over time, and outcomes with cranial surgery are not good. But, unlike me, individuals with SCD usually have typical hearing.
Uncovering the Source
When a CT scan, confusingly, came back negative for SCD, Dr. Raz said, “Lina, I think we may have learned the cause of your deafness. You don’t have SCD, but you do have an enlarged vestibular aqueduct, or EVA.”
Dr. Raz was also at Johns Hopkins, a resident working with Dr. Minor. She said they had talked about looking at the third window effect in patients with EVA and that it was likely, though there was no published data, that EVA also acts like a third window syndrome, similar to SCD.
The EVA itself is not necessarily the cause of the hearing loss but is associated with a mutation of the gene SLC26A4. A 2017 eLife paper discussed how this may
Opposite page: Before vestibular rehabilitation therapy, Lina Reiss found mountain biking extremely challenging.
This page: The four flights to Brazil for a family fishing trip on the Amazon triggered Reiss’s balance issues.
cause EVA by changing how the electrolyte sodium chloride, and thus fluid, is reabsorbed. This affects the development of the inner ear, and possibly plays a role in regulating endolymphatic pressure, which can affect hearing and balance.
The diagnosis fit with my progressive hearing loss as a toddler and my adult vestibular symptoms. I realized my imbalance was more like a milliseconds-long “lag” in balance orientation. In contrast, the vertigo in BPPV is described as a slower, room-spinning sensation for 30 to 60 seconds. Also, people with EVA sometimes experience sudden hearing loss after flying, so sudden balance problems after flying are plausible.
Genetic testing confirmed I have two different mutations in the SLC26A4 gene. This is consistent with the severity of my hearing loss and my South Korean ancestry, as heterozygous mutations in SLC26A4 are more common in East Asian populations.
After Diagnosis, Treatment
My imbalance issues, while not causing nausea, had a profound, disabling effect on my ability to concentrate, focus, and be productive. Finally after a few months, it had become tolerable, but I still had movement errors. I could ride my bike as long as my head wasn’t moving relative to my body, but if I stopped, turned my head to look for cars, and tried to turn left, I would end up going right instead. I would bend to pick up overripe apples in our yard, twist to throw them in the compost bin, and fall down.
I started vestibular rehabilitation therapy using classic exercises, such as focusing on a single letter while moving my head, and proceeding to walking with head turns. It took six months for me to gain small improvements to do this without losing my balance.
I moved on to a dynamic posturography machine, which involved standing in a phone booth-like box and trying to maintain my center of gravity while the walls and floor moved, sometimes in different directions. And I began using virtual reality goggles: Watching my husband steer a plane, I kept falling backward every time upward movement was simulated.
But after just a few weeks, these simulations ended up being dramatically effective and efficient, compared with the classic exercises. My vestibular function came back to what it was. I also recently got a cochlear implant.
In Facebook groups I had joined to learn more about balance problems, I saw that many go undiagnosed and untreated, and even with EVA—one of the most common genetic causes of childhood hearing loss—very little is known, including triggers and susceptibility. My hope is that more research will help us understand all the various types of balance conditions. In response to loud sounds—especially low-frequency sounds like my husband’s voice—I felt the room start to spin slowly. While disconcerting, this indicated to me that my vestibular cells could now respond to sounds, which would normally only be detected by auditory hair cells.
Lina A.J. Reiss, Ph.D., is an associate professor of otolaryngology–head and neck surgery, and of biomedical engineering, in the Oregon Hearing Research Center at the Oregon Health & Science University’s School of Medicine. A 2012–13 Emerging Research Grants scientist, she wrote about hybrid cochlear implants in our Winter 2014 issue, at hhf.org/magazine. For references, see hhf.org/summer2020-references.
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