Dr. Schmidt and I (Dr. Shakespeare) recently attended an audiology conference hosted by Oticon, where we heard a talk by Dr. Anu Sharma and her colleague, Dr. Hannah Glick, about their research on how early and properly managed hearing treatment might reverse some of the brain changes that happen from hearing loss – called cross modal reorganization.
“Cross modal plasticity is the adaptive reorganization of neurons to integrate the function of two or more sensory systems. It often occurs after sensory deprivation due to disease or brain damage. In these instances, cross modal plasticity can strengthen other sensory systems to compensate for the lack of vision or hearing. This strengthening is due to new connections that are formed to brain cortices that no longer receive sensory input.” – L. Lepore Lazzouni
(Dr. Sharma is amazing. The first talk I ever heard her give changed the way I counseled patients about their hearing loss. I was a fourth year student at the time. Naturally, I was interested in learning more about anything she was researching.)
The Inspiration for Cross Modal Research
At first, Drs. Sharma and Glick wanted to study the outcomes of treatment in children with cochlear implants – they wanted to determine if cochlear implants were an appropriate form of treatment for hearing loss in babies and young children or if children should be treated at an older age. They did this by looking at what happens in the brain in a child that is deaf or hard of hearing without intervention, and then what happens in the brain over time with early intervention.
Cross modal reorganization occurs in children with any degree of hearing loss, and the research team found signs of visual reorganization and a loss of auditory cortex functions in the brain scans of children who had no hearing treatment. The doctors wondered if earlier cochlear implants were the solution to avoiding this reorganization. They found that in children who were implanted early, their brains resembled their normal hearing peers’ more closely, meaning they didn’t have that brain reorganization, or it was reversed.
In individuals who were implanted later, that cross modal reorganization did not reverse. The next step was to find the best age to implant a child with a cochlear implant for language development and listening skills, and they found that the earlier the implant, the better the outcome.
Drs. Sharma and Glick’s research on adults began by studying the brain’s response to sound, visual, and somatosensory stimuli in individuals with no hearing loss vs. individuals with mild hearing loss. Even in this study group, they found evidence of cross-modal reorganization.
Sharma’s brain scans of this study group showed that cortical reorganization is happening much sooner than we previously thought, and also showed that audiologists should start hearing treatment when the early signs of hearing loss show, even if only in one ear. This way, brain reorganization can be recovered, and the correct parts of the brain can reclaim their areas instead of invading others.
Second Stage of Early Hearing Treatment Research
What was really neat about the second stage of their research was seeing what happened when the researchers provided this hearing treatment early on.
Within six months of being professionally fit with hearing aids, they actually saw the brain function return to near normal and then also score closer to normal on other cognitive assessments, such as for working memory.
To get the best data, the doctors had to make sure their group participants were wearing the hearing aids for a minimum of six hours a day. We always tell our patients to wear their hearing aids while they are awake to get all the benefits of treatment, and now we’re seeing that six hours a day is the minimum requirement if they want to reverse any brain reorganization.
Hearing is an “eyes open, ears on” activity. When you’re not wearing your hearing aids, your brain gets tired quickly from straining to listen and understand. When you wear your hearing aids all day, your brain is not as exhausted, and it has the brain space to do other things, like remember what you made for dinner last night or carry on a conversation with loved ones.
Now, when we hear a patient say they just want to take their hearing aids out at the end of the day because they’re exhausted, we need to explain that their brain will become even more exhausted if they do because they’re putting stress on other systems again.
Confirming the Data
For the next part of their research, the research team tested a random selection of people in Colorado who had a hearing loss and were wearing hearing aids and found most of those people were wearing hearing aids that were not appropriately fitted prescription hearing aids. When they did brain scans on this study group, they found that their hearing ”treatment” did not reverse their re-organizational occurrence in the brain.
We really need to fit people early and appropriately with hearing aids.
I (Dr. Schmidt) come from the world of pediatric audiology, and for a long time, we focused more on how children’s brains had lots of neuroplasticity but thought there wasn’t much in older people’s brains. That’s not true, which means we can reverse some of the losses in older patients if we can get there early enough. We can even accomplish some positive effects when beginning hearing treatment for a moderate hearing loss, but not as many.
This is of enormous value in helping lessen or delay the risk of Alzheimer’s or dementia, and so this research ties into that as well.
Prevent or Reverse Cross Modal Reorganization in Your Own Brain
Whether you’re an adult with a hearing loss or your child has a hearing loss, here are the two steps you need to take to avoid any decline in your brain health:
- Get your hearing checked so you can start with a baseline set of results. Also, if your child is not listening to you at a young age, it could well be because they have a hearing issue. Let us check your kid’s ears too.
- Have the conversation and make informed choices. Without the information, you can make lots of assumptions. You can Doctor Google your way to a lot of decisions, but it’s better just to know what’s actually going on and if you have a hearing loss that can be treated.
Schedule an appointment with us today! We offer free consultations to help you find the best way to improve your hearing and reverse any decline in brain health. Or give us a call at 541-612-7555 to speak with one of our friendly and knowledgeable team members.
We look forward to helping you with your hearing needs.