Science reports that a serendipitous discovery by Hubert Lim, a biomedical engineer at the University of Minnesota has led to a new treatment of tinnitus: using electrical shocks in other parts of the body.
It’s “really important” work, says Christopher Cederroth, a neurobiologist at the University of Nottingham, University Park, who was not involved with the study. The finding, he says, joins other research that has shown “bimodal” stimulation—which uses sound alongside some kind of gentle electrical shock—can help the brain discipline misbehaving neurons.
The experiment involved 326 people with tinnitus receiving electrical shocks to their tongue whilst listening to background noise on headphones.
Over the 12 weeks of treatment, the patients’ 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 one to 100, the researchers report today in Science Translational Medicine. 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.
The results are “quite impressive,” Cederroth says. The reduction in symptoms is larger than other studies have found for bimodal stimulation, he says, and it’s the first evidence of such long-term effects. A 2018 paper that stimulated the skin on the neck and cheek over a shorter time improved patients’ tinnitus, but there was a smaller dip in severity scores, he notes, of only about seven points. And cognitive behavioral therapy, a kind of talk therapy that is currently the only clinically validated tinnitus therapy, improves severity scores by about 10 points on average.
Still, University of Oxford neuroscientist Victoria Bajo notes 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 or with a placebo. The work is good, she says, “but this is the beginning.”
