Georgetown Study Links Causes of Tinnitus to Protective Brain Responses

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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.

 

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

 

Mine, too! I can hear those neurons firing right now!!