Georgetown Study Links Causes of Tinnitus to Protective Brain Responses

article

For 62 years, Gloria Chepko has lived with what she describes as the sound of crickets in her ears.

“It’s a ringing,” said the cancer researcher of the noise she hears. “It’s actually like thousands of crickets, but it has a bell-like quality, a high pitch.”

Even at age four, she knew the name of her condition: tinnitus.

“One day, I said, ‘Daddy, what’s the sound you hear before you hear something? It’s like whee, whee, whee, whee,’” Chepko recalled.

“That’s tinnitus,” Chepko’s father, a doctor, replied. “Some people have it.”

That was all he said, as not much was known about tinnitus back then.

But a new study released today by the Georgetown University Medical Center sheds more light on the disorder as a protective response of the brain. The report, called “Dysregulation of limbic and auditory networks in tinnitus,” reports that this is not just a hearing disorder. Rather, the ringing sounds are caused by brains that try but fail to protect humans against overwhelming auditory stimuli. Essentially, the brain is working in overdrive.

Amber Leaver, a post-doctoral researcher on tinnitus at Georgetown and one of the paper’s authors, described tinnitus as hearing a whirring or ringing in the absence of any actual sound from the environment.

In the study, researchers compared MRIs of the brains of 11 volunteers with tinnitus to images of the brains of 11 people without the disorder. Examining brain activity and anatomy, they found differences in the auditory part of the brain and, importantly, differences in the limbic system.

The limbic system evaluates an individual’s world and helps filters out unwanted information - noises, pain, or even thoughts and emotions. The limbic systems of tinnitus patients function hyperactively, assigning importance to the tinnitus sensation when no sound is actually present.

“The field as a whole thinks of tinnitus as strictly an auditory disorder,” said Leaver. “This finding might change research and how it’s thought of (by doctors).” And the hyperactivity in the limbic system may also cause depression and disorders such as chronic pain and other perceptual disorders. Leaver used the example of when a person has a limb removed but still “feels” the limb there. “This is because of the brain’s inability to recognize that the limb isn’t there anymore,” she said.

Chepko, who now works at the National Library of Medicine, saw a notice seeking research participants at Georgetown, where she herself worked at the time, pursuing breast cancer research. She volunteered to be one of the 22 subjects for the study.

The American Tinnitus Association estimates that over 50 million Americans experience tinnitus. Of these, about 12 million have severe enough symptoms to seek medical attention, and about 2 million are so seriously debilitated they can’t function on a day-to-day basis.

Tinnitus occurs more frequently among the elderly and recent war veterans, making proper diagnosis and treatment a growing concern, the study reports. The exact cause or causes are unknown, but several likely sources are known to trigger or worsen tinnitus, according to the American Tinnitus Association. Some things which can lead to tinnitus are exposure to loud noises, head and neck trauma, certain types of tumors, jaw misalignment, diabetes, cardiovascular disease, reactions to medications and earwax buildup.

Treatments for tinnitus vary depending on the cause. When tinnitus is a symptom of another disorder, treating the disorder can help alleviate it. But it is harder to treat when the causes are unknown, as with tinnitus without a link to any other condition. There are no well-known drugs or alternative medicines that have proven successful for this "idiopathic" tinnitus, said Dr. Ernest Mhoon, an ENT at the University of Chicago Medical Center. The most effective treatment is called masking, which drowns out the noise in one’s head with an external noise so that the phantom noise fades into the background.

Masking can be done with hearing aids, sound generators or other devices. A newer treatment is tinnitus retraining therapy, a type of psychotherapy using maskers and counseling which helps patients learn to live with their tinnitus.

While the noise comes and goes in frequency and severity, Chepko noticed that physiological or psychological stress seemed to bring it on or make it worse. When it becomes impossible to ignore anymore, she relaxes by reading, looking at pictures, or playing Solitaire, and tries to mask the sounds by listening to music or the radio or watching TV. Once she recognized the patterns and learned coping mechanisms, she felt like she had more control over it.

Leaver said it is hard to tell yet if it will change how people seek treatment for tinnitus because few treatments work consistently. But it may influence the behavioral treatments - how people learn to deal with it. Also, raising awareness of the symptom and how common it is might make people more aware of whether they have it, and more likely to seek treatments.

 

Good article Erik! Sums it up nicely. Thanks

 

In what way is this different than Jastreboff's Neurophysiological Model, which he developed in the 1980's? He discussed how tinnitus develops in terms of the limbic, autonomic and auditory systems, and how a viscious circle gets going. I'm not seeing what the new ideas are in this article.

 

erik....thanks

ok so they found out that people with tinnitus have differences in the limbic system as compared to those without tinnitus...

"In the study, researchers compared MRIs of the brains of 11 volunteers with tinnitus to images of the brains of 11 people without the disorder. Examining brain activity and anatomy, they found differences in the auditory part of the brain and, importantly, differences in the limbic system. "

what id like to know next, is

were the changes to the limbic system a precursor and a precondition to tinnitus...or a result

my guess is somebody is working on that as we speak

best wishes
mock turtle ( aka mach turtle because today, the ringing in my ears is swirling around my head at the speed of sound)

 

Surely the limbic activity is as a result of T because that's exactly what Jastreboff says ie. with T the Limbic System gets involved then the ANS.

If something upsets you the limbic system is involved isnt it?

Sorry about the noise today Mach T.

 

Louise...appreciate the sympathy, yeah its been especially nuts lately, twice as loud in the left ear v the right

i guess this might sound incredibly stupid, but, i wish i could take some of the tinnitus from the left ear, and give to the right, to "balance" things out...it is so crazy

oh, yeah, and about the limbic system...thats what i thought, that the limbic changed as a result of the T

but...what if.... just supposing, what if some people have an over active limbic system, to begin with...would that increase the possibility of tinnitus? ...just guessing

best wishes
mt

 

I know what you mean about that balancing thing MT. When that happens though doesnt the noise then seem more central? I hope its slowed down for you anyway.

I think you could be right about the limbic system thing. It would mean you were an emotional type wouldnt it? Or a stressed out type. Wouldnt that make the limbic system more active?

Does fear come from the Limbic System?

 

yes, i think so, especially fear, and other emotions and memory especialy from trauma and the memory of the emotions and the events that sparked those emotions

that why i found markku's thread about fears or phobias thought provoking

 

I bet my limbic system is lit up like a beacon!

 

btw i re read the article you linked to in another thread, from "neurotransmitter review" and its causing me to rethink my off the cuff remarks about alcohol...

really excellent article

and yes, my limbic system works overtime...im a notorious "hyper vigilant" type personality

example before the family would go on vacation id be checking tire pressure on the spare, and making sure we had lots of stuff related to "what if"...such as first aid kit, jumper cables for a dead battery etc...i worry too much

 

erik

in re reading the article y0u linked to, about mri s, and the limbic system and then thinking about Louise's thread on alcohol sets me to thinking about connections...could alcohol use, especially abuse, be a significant risk factor for tinnitus...my guess is yes

because if alcohol increases the number of NMDA receptors in the amygdala (part of the limbic system) and other places in the brain, related to the perception of T then it seems to me that increased neuron firing and limbic activity is the result

 

mt -

Whoo,... slow down there Trigger! No alcohol! (Next topic, please)

 

Gotta have my microbrews and occasional Tequila, vodka, rum or hard cider. Makes the T go off the deep end but I don't really care when I am out having a good time

 

I don't drink, but I know my amygdala is stuck in fight or flight alot!!

 

Karl...erik... ok..ok..im not suggesting prohibition...ivr been known to tip a few back every now and then

Calin...Karen... i suspect a lot of us are "poised" on the edge of our seats and easy at the slightest hint of trouble to spring into action...ever vigilant...

to put it simply ...im hyper, and i suspect many a tinnitus sufferer is just so...but im guessing

best wishes
mt