Tinnitus – a constant ringing or buzzing in the ears that affects about 15% of people, is difficult to understand and even harder to treat.
A few years ago, a close friend suggested that I see an ear, nose and throat specialist who was a friend of her son’s, to see if my tinnitus could be cured. Nothing came of the examination except the doctor lady (???) asking me if I was hyperactive. I couldn’t understand the connection and answered that I was just active and decided to forget about my tinnitus.
Now, scientists have shown that shocking the tongue – combined with a carefully designed sound program – can reduce symptoms of the disorder, not just while patients are being treated, but up to 1 year later.
It’s really important work, says Christopher Cederroth, a neurobiologist at the University of Nottingham, who was involved with the study. The finding, he says, joins the research that has shown “bimodal” stimulation – which uses sound alongside some kind of gentle electrical shock – can help the brain discipline misbehaving neurons.
Hubert Lim, a biomedical engineer at the University of Minnesota, hit on the role of the tongue in tinnitus by accident. A few years ago, he experimented with using a technique called deep brain stimulation to restore his patients’ hearing. When he inserted a pencil-size rod covered in electrodes directly into the brains of five patients, some of those electrodes landed slightly outside the target zone – a common problem with deep brain stimulation, Lim says. Later, when he started up the device to map out its effects on the brain, a patient who had been bothered by ringing ears for many years, said, his ears weren’t ringing anymore.
For many people it’s the brain that’s to blame, perceiving sounds that aren’t there. One potential explanation for the effect is that hearing loss causes the brain to overcompensate for the frequencies it can no longer hear.
Further testing on guinea pigs revealed the best body parts to stimulate to shut off tinnitus. Lin says. He and his colleagues tested the ears, neck, limbs and “other places”, eventually concluding that the tongue was the best target.
Then Lim turned to humans. In the team’s experiment, 326 people with tinnitus sat for up to 1 hour at a time with small plastic paddles on their tongue. Tiny electrodes in the paddle delivered an electric current designed to broadly excite the brain, getting activity going through a number of interconnected regions. Apparently, the electrical stimulation felt like an effervescent candy fizzing in your mouth.
Subjects also wore headphones that delivered a more targeted hit to the brain’s auditory system. Each person heard a rapidly changing series of pure tones at different frequencies, against a background noise that sounded kind of like electronic music.
The goal of the two together was to distract the brain by heightening the sensitivity, forcing it to suppress the activity that caused tinnitus.
Over the 12 weeks of treatment, the patient’s tinnitus symptoms improved dramatically. More than 80% of those who complied with the prescribed regimen saw an improvement. And they saw an average drop of about 14 points on a tinnitus severity score of 1 to 100.
When the team followed up after 12 months, 80% of the participants still had lower tinnitus scores, with average drops of 12.7 and 14.5 points.
University of Oxford neuroscientist Victoria Bajo notes that there was no control group in the trial. Without that, she says, it’s impossible to know how much patients would have improved on their own with a placebo. The work is good, she says, “but this is the beginning.”
You will not be able to stop the ringing in your ears tomorrow my friends but help seems to be on the way.
That’s it for now, see you all the next time.
