Using a magnet to generate an electrical current in areas of the brain that control hearing does not seem to improve ringing in the ears, a new study suggests.
Researchers found people reported just as much bothersome ringing after a month of so-called repetitive transcranial magnetic simulation (rTMS) as after a series of fake, magnet-free treatments.
Although it seems natural that ringing in the ears - known as tinnitus - would be a hearing-related problem, so far medications and magnetic stimulation targeting the brain's auditory areas haven't made the sound go away, according to Dr. Jay Piccirillo.
"People want a pill to make it go away, but there isn't anything like that," Piccirillo, an otolaryngologist from the Washington University School of Medicine in St. Louis, told Reuters Health. "There's no cure for tinnitus."
Up to 50 million Americans report chronic ringing in the ears at some point during their lives, research suggests. Although that experience is common, Piccirillo said only about one-fifth of people who do hear ringing are bothered by it enough to disrupt their everyday lives.
Current treatments for those individuals include devices to mask the sound, antidepressants to lessen its bothersome effects or talk therapy, yoga and meditation.
In Europe, doctors have been using rTMS to create electrical currents in the auditory nerve for people with tinnitus, seeing a "mild to moderate, short-lasting effect," according to Piccirillo.
He and his colleagues previously tested two weeks of rTMS treatments on people with tinnitus and found it had no benefit.
For the new study, they gave 14 people with tinnitus four weeks of rTMS and four weeks of a sham, magnet-free treatment. Study participants reported having had tinnitus for at least six months and started out with an average tinnitus handicap score of 52 on a scale from 0 to 100.
That score dropped by an average of 10 points after rTMS and by six points after the sham treatment - a difference that could have been due to chance, the study team reported in JAMA Otolaryngology - Head & Neck Surgery.
Researchers believe tinnitus is the result of over-activity in certain areas of the brain - and in theory, rTMS should suppress some of that activity, according to Josef Rauschecker, from Georgetown University Medical Center in Washington, DC.
However, "Neurophysiologically, it's not at all clear what it does," Rauschecker, who has studied that question but wasn't part of the study team, told Reuters Health.
John Rothwell, who has researched brain stimulation for tinnitus at University College London, said a number of small studies have looked at this treatment and all have the same problem: the response to stimulation varies greatly from one person to the next.
"You'll find in all of these trials, some people will get better, some people will get worse and most will stay the same," Rothwell, who also wasn't involved in the new research, told Reuters Health.