In this video, a tinnitus researcher discusses the perception of sound without an external source, known as tinnitus. She explains that tinnitus is often described as a ringing in the ears or head and can be caused by exposure to loud noises. The researcher delves into the concept of phantom sensations and how tinnitus is similar to phantom limbs. She shares her findings on the involvement of the prefrontal cortex in tinnitus and discusses the use of repetitive transcranial magnetic stimulation (rtms) to alleviate symptoms. The video highlights the increasing research and hope for developing treatments to reduce and manage tinnitus.
Key Insights:
- Tinnitus is the perception of sound without an external sound source, often described as a ringing in the ears or head.
- One in 12 people experience chronic tinnitus, while one in five experience intermittent tinnitus.
- Tinnitus has been linked to anxiety and depression.
- Tinnitus is a phantom sensation, similar to phantom limbs, where the brain compensates for the lack of sensory information from the auditory system by generating a phantom perception of sound.
- The prefrontal cortex, a brain region involved in attention and decision making, was found to be altered in tinnitus patients, despite not traditionally being associated with sound.
- Repetitive transcranial magnetic stimulation (rtms) is a non-invasive device that uses magnets to modulate the prefrontal cortex and potentially alleviate tinnitus.
- There is still ongoing research to determine the effectiveness of rtms in reducing tinnitus in humans, and whether it provides long-term relief or just temporary reduction.
- The number of studies and research on tinnitus has increased significantly over the years, indicating progress in developing treatments and improving the quality of life for tinnitus sufferers.
Transcript
Foreign: I’d just like to play a quick sound for you. I have a confession to make. I didn’t actually play anything, but if you experience tinnitus, you might have found that difficult to suss out. Tinnitus is the perception of sound without an external sound source. It’s often described as a ringing in the ears or head. You might not consider yourself as experiencing tinnitus. Think about the last time you went to a loud noise event, a concert, the footy game, maybe out to a club. You might have after a couple of hours turned over to your mate and said, „Hey, do you hear that ringing?“ Only for them to say, „What ringing?“ That was tinnitus. Just so you know, you might have had a moment of panic. Will I ever be able to hear at the volume I did before? Will that tinnitus ever go away?
For one in 12 people, that ringing doesn’t actually ever go away. One in five people experience intermittent tinnitus. I experience intermittent tinnitus, and I get a little scared when I think about when my brain won’t be able to tune out that tinnitus. Will it become chronic? Will I no longer be able to sleep? Tinnitus has been linked to anxiety and depression. Will I be nervous in conversations, become embarrassed, and stay at home? I’m a tinnitus researcher, so today I’m going to tell you about what we’re doing to treat tinnitus, but I’ll give you a little bit of background.
When I started my PhD, I knew nothing about hearing loss and tinnitus. I knew that the prevalence of both was largely increasing, mostly because the population age was increasing. So, hearing loss and tinnitus are generally increasing as our population gets older. But I didn’t know if there was anything that could be done about it. I felt like it was just something that happens as you age. Maybe I could wear earplugs more, turn down the volumes in my headphones. And it wasn’t until my supervisor told me about phantom sensations that I realized that tinnitus was more than just what was going on in your ear.
Now, phantom sensations, you probably haven’t heard that term before, but maybe you’ve heard of phantom limbs. I want you to think about your arm for a second. Think of all the sensory information your arm sends to your brain, things like touch, temperature, and unfortunately, pain. Now, I have terrible news for you. You’ve been in an accident; the arm’s got to go. You go under and you wake up, and there’s been an amputation. All of that rich sensory information that used to go to your brain is now gone. Your brain understandably is a bit confused, and it compensates by generating a phantom limb of what used to be there. Tinnitus is sort of the same phenomena but instead for your auditory system.
Now, I want you to imagine again that you’re at a concert. You’ve forgot your earplugs, and you’ve made another bad decision. You stood next to the speakers all night. The cochlea, the hearing organ of your ear, is a little worse for wear, and that sound information that your brain is so used to receiving is gone. You have a hearing loss, and your brain compensates by generating the phantom perception, tinnitus.
Now, when I found this out, it blew my mind. I became obsessed. You can have phantom perceptions of any sensory system, even phantom smells. So, I started my PhD, and I looked at the research that was already done. They found areas of the brain, such as the auditory pathway that looked from the ear all the way to auditory cortex. They looked at how they were damaged after hearing loss and where. But something wasn’t quite adding up. It didn’t seem this auditory pathway alone was enough to generate tinnitus, and that not everybody with hearing loss would go on to develop tinnitus. So, what else was at play?
And that’s where we had some human imaging studies come in. They found that this area that I have in green here, called the prefrontal cortex, that’s normally considered to be involved in attention decision making, it was altered in tinnitus. This was confusing to everybody. We didn’t know why. It wasn’t traditionally thought to be involved in sound. What could be going on? And we thought, hey, this would be a great PhD project. Little did I know what that would mean.
So, with support and approval from the UWA Animal Ethics Committee, I went about trying to see how this prefrontal cortex might impact the auditory pathway. So, we started off to see, was there any sort of connection between these regions and was it functional? And it was. And it worked. Then I wanted to see, whoa, what happened after hearing loss? Kind of surprising, because this wasn’t an area traditionally thought to be involved in hearing. It was damaged, and that kind of has far-reaching implications, doesn’t it? This area, not traditionally thought to be involved in sound, was being affected by something happening in the ear.
So, we moved on a little bit, and then we found if you modulated this pathway, you could alleviate tinnitus. So, that’s it. We’ve done it. We’ve cured tinnitus. Oh well, that’s a great PhD, isn’t it? I’ve done well. But, of course, it’s not that easy. All of my work was in animal models. So, how do we modulate this pathway? Is it invasive? Is it pharmacological? Well, I’ve got good news for you. We used a device called repetitive transcranial magnetic stimulation, which is obviously extremely catchy, and I know you’re all going home and singing that later. But I’m going to refer to it as rTMS.
So, rTMS is a non-invasive stimulator that uses magnets, so it’s pretty good. The problem is, there are lots of parameters you can change, and in our models, we’ve changed lots of them. Sometimes it didn’t have any effect on tinnitus, but sometimes it did. But this was also in animal models. So, what are people doing in human studies? Well, the results there are a little bit more variable. Sometimes it can alleviate tinnitus, sometimes it just reduces people’s perception of how loud their tinnitus is, which in both cases is a pretty good result. But we don’t yet know if it will completely reduce people’s tinnitus forever or if it’s just short-term.
So, there’s a lot of work that needs to be done, and why animal studies like mine still need to go ahead. When I was born, only 113 papers on tinnitus were published. Last year, there was over 1,100. That’s a 10 times increase in the amount of work being put out there on tinnitus, things improving quality of life, treatments, and things like pharmaceuticals and cognitive-behavioral therapy. And that gives me hope that we’ll have treatments for chronic tinnitus, that intermittent tinnitus like my own might not become chronic. And I hope that after today, it does for you too, that we’re one step closer to developing treatments to tune out tinnitus. Thank you.
[Applause]
