Tinnitus detectable as structural changes in how the brain processes thought and emotion

I’m a person with Tinnitus.

When I was a child I thought it meant you had a tin ear – that it meant you couldn’t hear or differentiate musical tones the way most people could. I’ve since learned that’s not what it means.

What it means to me is that there is a background noise to my life that never goes away completely. Right now as I sit here there’s an air cleaner running quietly in the room, a TV going in the other room, the occasional car or truck passing by outside and every now and then the air conditioner turns on.. But mixed in with that is a hiss; it has a slight;y high pitched edge dancing on top but most of the time it’s a hiss.

The way I describe it most of the time is to say ‘It’s like there’s a water tap running in a bathroom elsewhere in the house.’ Sometimes it gets louder and becomes a ringing in my ears. Most of the time I forget it’s there – the real world is too noisily busy to notice it. But it never ever goes away completely.

When I first moved out on my own I found myself always listening to either the radio or music when I went to sleep (all night TV wasn’t a thing back then and VHS hadn’t been invented let alone DVDs or steaming media). I later learned that nearly all people with tinnitus do the same. It’s because when the real world gets really quiet the internal noise becomes all that much more noticeable.

People with severe symptoms can find their ability to carry on a normal life badly disrupted. Effects can range from simply being debilitating to driving people insane. Thankfully mine is not that bad – I can carry on a fairly normal life and it doesn’t prevent me from enjoying it for the most part.

I wasn’t born with it, I think.
I’m pretty sure mine comes from noise-induced hearing loss. And I know exactly how it happened because I did it to myself – at the time I was only 8 and had no idea I was destroying my hearing and setting off structural changes in my head. I was just doing what 8 year olds do, exploring the limits of my world.

Long story short: I subjected my ears to an extremely loud horn pushed up nice and tight because there was a slight tickling sensation at the loudest point. For two days all I could hear was a loud screaming ringing in my ears – I bluffed my way through those days and didn’t let on I couldn’t hear a thing. Eventually the ringing died off and the hearing came back. The ringing sound never completely went away though . . . and the hearing probably never completely came back either. C’est la vie . . . enough about me.

Medical science knows that tinnitus comes from damage to the hearing system but beyond that little is known. There has been no external way to verify someone has it for instance. Other than their own testimonials there was no test that could be done to differentiate those with the condition from those without it.

Until now that is.

A team headed by Fatima Husain, University of Illinois speech and hearing science and neuroscience professor, has been conducting research using Functional MRI imaging and has shown changes in how the brains of tinnitus patients work when compared to those without it.

In the first I’ll mention she was “trying to understand how the brain adapts to having tinnitus for a very long time”. I’ve had it for over 50 years so I think I’d be in that cohort.

What did her team do? “Using fMRI, Husain’s team previously compared how the brain processes emotion in patients with mild tinnitus and people without the condition”

What did it find? ” … in contrast to those without tinnitus, patients with mild tinnitus showed greater engagement of different areas in the brain when processing emotional sounds.”
Okay, what about patients with not so mild tinnitus? “To further understand this altered brain activation, Husain conducted a new fMRI study to see if there were any differences among tinnitus patients. Because some patients adjust to the ringing in the ears while others do not, the severity of the condition can vary greatly.” I think I’ve been able to have a life not greatly affected by the condition.

What does that mean? “Patients with lower tinnitus distress used an altered pathway to process emotional information. The path did not rely on the amygdala, commonly believed to play an important role in emotion processing in the brain. Instead, patients who had adapted to their tinnitus symptoms used more of the brain’s frontal lobe, a region critical for attention, planning and impulse control. The researchers suggested that the greater activation of the frontal lobe might be helping to control emotional responses and reduce tinnitus distress.”

So does that mean that the brains of most of you (readers without this condition) use the one of the oldest parts of your brains’  architecture, the amygdala , to process the emotional content of stimulae but I do not? That my condition has disrupted the utility of that resource and forced my brain to enlist capacity in the most recently developed part of the brain, the frontal lobes?

Hmm . . . all kinds of questions arise here.
What is causing this break in the connection to, or usability of , the amygdala?
How does this drafting of portions of the frontal lobe for this task affect the other activities of the frontal lobe?
In what way do I, and other low stress tinnitus patients, process emotional content differently from you who do not have the condition?
The Amygdala is also central to memory. If tinnitus affected using it for one function how has it altered use of this aspect of it’s function? Do I remember things in a mechanistically different way than you?

The second item (also from ScienceDaily.com) is by the same researcher.

This is more of what she has learned using that great new tool fMRI.

“Using functional MRI to look for patterns across brain function and structure, the new study found that tinnitus is, in fact, in the hearers’ heads — in a region of the brain called the precuneus, to be precise.
The precuneus is connected to two inversely related networks in the brain: the dorsal attention network, which is active when something holds a person’s attention; and the default mode network, which are the “background” functions of the brain when the person is at rest and not thinking of anything in particular.
. . . The researchers found that, in patients with chronic tinnitus, the precuneus is more connected to the dorsal attention network and less connected to the default mode network. Additionally, as severity of the tinnitus increased, so did the observed effects on the neural networks.
. . . It also implies that tinnitus patients are not truly at rest, even when resting. This could explain why many report being tired more often. Additionally, their attention may be engaged more with their tinnitus than necessary, and that may lessen their attention to other things. If you have bothersome tinnitus, this may be why you have concentration issues”

I just learned of the Default Mode Network this past year and the ramifications of it are still percolating through my mind. And now I find that it’s maybe not being used as much (or in the same way) as it is in ‘normal’ people. Well geeee whiz – now I’m more curious than ever about it.

For those who haven’t heard about the Default Mode Network it’s another thing that was suspected for a long time but actual verification was discovered after researchers began using fMRI to peek inside operating brains.

Ever since Hans Berger invented the EEG and noticed constant electrical activity there has been a suspicion that the brain is always working no matter how rested or inactive the person appears. Later research showed that some areas of the frontal lobe became less active during focused thought. And that there was only a 5% difference in metabolic activity between resting and fully engaged brains. But it took fMRI to actually see the various parts of the brain firing in bouts of interrelated activity while a person wasn’t actually consciously thinking of anything at all.

All in all my first take-away from all of this news if I sure am happy that brain function is so dam plastic. If it wasn’t then the mal-connect with my amygdala caused by my tinnitus might have left me seriously damaged in some fundamental and debilitating way. The fact that another part of the brain can be repurposed to perform the job the system cannot use the amygdala for is part of that plasticity. That it’s affect on the normal functioning of that part of the brain is not noticeable to myself or others in any way can also be credited to that same plasticity.

Another title for this could have been ‘Brain Plasticity Protects Against Dumb Choices’

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About xamble

Most things I do involve computers. Nowadays that sounds stupid to hear because everyone uses computers. Except I was saying that before the IBM PC came on the scene. (hint: my first programs were entered on punch cards in an IBM-29) Now I mostly use them. Mostly to provide a community service in my small town. Because I could when it was asked and still can. And I'm a wannabe writer. Various books in various states of incompleteness. A few short stories. Might do more of that.
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One Response to Tinnitus detectable as structural changes in how the brain processes thought and emotion

  1. Ponita says:

    I’ve had tinnitus since my early 20s, which I am pretty sure is directly contributable to rock concerts at the arena. I recall not being able to hear very well for several days after an AC/DC concert. Mine sounds like the tubes in an old tv buzzing and humming. It changes pitch frequently and once in a while, changes volume suddenly. After a few seconds or a minute, it goes back to the ‘regular’ volume. Sometimes I seem to have difficulty hearing voices, but other times, I can hear tiny little sounds (especially at work, when attuned to alarms on machines) very well. Go figure! I’ve learned to tune it out, especially at night, so it doesn’t stop me from sleeping. (But perhaps the tiredness is from all that brain activity.) During the day, I almost always have the radio on, but nothing at night. Now that they have figured out where it is located in the brain, perhaps someone can figure out how to stop it! Great information. Thanks.

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