Sounds like treble.
Some 50 million to 60 million Americans have experienced a ringing, buzzing or clicking in their ears that no one else hears, a frustrating condition known as tinnitus.
An estimated 15% of tinnitus sufferers have a severe case that disturbs their sleep, mental health and daily routine.
Now, researchers at Mass General Brigham have identified two involuntary, agonizing signs in tinnitus patients that appear “hidden in plain sight.”
“These biomarkers get to the root of the distress,” said corresponding study author Daniel Polley, vice chair for basic science research and director of the Eaton-Peabody Laboratories at Mass Eye and Ear.
What causes tinnitus?
The phantom sounds can be caused by a variety of factors, including hearing loss, prolonged exposure to loud noise, ear infections, earwax buildup, medication side effects, head injuries and conditions like Ménière’s disease, an inner ear disorder.
How is tinnitus diagnosed?
Physicians diagnose tinnitus based on medical history, a physical exam, hearing tests and in some cases, imaging scans.
Tinnitus severity is typically measured using questionnaires, psychoacoustic tests and clinical evaluations.
Enter Polley’s team.
“Imagine if cancer severity were determined by giving patients a questionnaire — this is the state of affairs for some common neurological disorders like tinnitus,” Polley said.
2 novel biomarkers for tinnitus
Polley and his colleagues focused on the sympathetic nervous system, the body’s “fight, flight or freeze” mechanism.
They recruited 97 volunteers — 47 had varying levels of tinnitus and sound sensitivity and 50 had normal hearing — to listen to pleasant, neutral or irritating sounds.
The team used AI-powered software to detect the participants’ rapid and subtle involuntary facial movements. The twitches in their cheeks, eyebrows or nostrils corresponded to tinnitus distress levels.
“For the first time, we directly observed a signature of tinnitus severity,” Polley said. “When we began this study, we didn’t know if sounds would elicit facial movements; so, to discover that these movements not only occur, but can provide the most informative measure to date of tinnitus distress, is quite surprising.”
Polley also noticed that when people with severe tinnitus listened to different sounds, their pupils dilated extra widely.
People without tinnitus or with less serious tinnitus had exaggerated pupil dilation and facial movements only when hearing the most unpleasant sounds.
The findings were published Wednesday in the journal Science Translational Medicine.
How the new research may help treatment
There isn’t a cure for tinnitus — hearing aids, sound therapy and cognitive behavioral therapy can help manage symptoms.
Polley and his lab are using the results from this study to devise new therapies that combine neural stimulation with immersive software designed to reduce the perceived loudness of tinnitus phantom sounds.
“What’s really exciting is this vantage point into tinnitus severity didn’t require highly specialized brain scanners; instead, the approach was relatively low-tech,” Polley said.
“If we can adapt this approach to consumer-grade electronics, they could be put to use in hearing health clinics, as objective measures in clinical trials and by the public at large.”
Polley also plans to expand his research to include tinnitus patients with co-occurring issues like hearing loss, advanced age or mental health challenges. They were excluded from this study because of the limited participant pool.
