Researchers recently uncovered the brain mechanism behind tinnitus, a condition that causes incessant ear ringing, but one center in the UK claims it has already been successfully treating the affliction for more than a year.
Nathan Dundovic at the Tinnitus Treatment Centre said the organization's combination of Transcutaneous Vagus Nerve Stimulation (tVNS) and Tailored Sound Therapy (tST) has offered relief for people with the condition, which affects up to 30 percent of the adult population.
Stimulation of the vagus nerve has been used to treat illnesses including epilepsy and depression for decades now, and has been considered for the treatment of tinnitus, but it was previously administered through a surgically implanted electrode. The SaluStim device, developed by the Tinnitus Treatment Center and Helsinki Ear Institute, uses an electrode clamped onto the patient's left outer ear for tragus nerve stimulation. Dundovic said it has proven successful for many users with tinnitus.
"In many medical schools it is still taught that there are no treatments for tinnitus, which is quite astounding really."
"In terms of medical device development the SaluStim is still relatively new and as of yet a systematic review of its effectiveness hasn't been conducted beyond individual patient follow ups," he said. "That said, some patients have been using the SaluStim almost daily for three years and have said they couldn't imagine life without it."
Several studies have proven tVNS treatment successful for other conditions. A 2015 study found chronic migraine sufferers saw a 50 percent reduction in headache days after using tVNS. Another study showed 22-37 percent of depression patients saw fewer major depressive episodes after tVNS.
As a study published this month in Trends in Cognitive Sciences found, tinnitus is caused by a defective "gatekeeping" system in the brain. Dundovic says that system can also be successfully rebalanced by targeting the vagus nerve.
"The study confirms our treatment practice," Dundovic said. "One of the things stimulating the vagus nerve does is it stimulates the parasympathetic nervous system, which interrupts this feedback loop and promotes neuroplasticity in the brain––it helps the brain rewire itself."
However, Josef Rauschecker, director of the Laboratory for Integrative Neuroscience and Cognition at GUMC and one of the Trends study's authors, said there is not a lot of reliable data to back up the vagus nerve theory.
"There are no good theories of how the vagus nerve has an influence on higher brain structures," he said. "It might have to do with the mechanisms we have been discussing, and the system we were talking about in our study, but I think this is all very unproven."
Rauschecker added that isn't to say it cannot be effective, just that more research needs to be done. He said if imaging studies currently underway could be collaborate with research on vagus nerve stimulation, we could get a better picture of the mechanism behind it.
"Often in the medical community you find something that works and later you find out how it works," he said. "I find the whole thing very interesting, there has to be something to it, but we don't yet know what."
Meanwhile, the Tinnitus Treatment Centre's device has gained regulatory approval in the European Union and is pending FDA approval in the United States. With further testing, the treatment could have a variety of applications beyond tinnitus, including relief for chronic pain sufferers, once more people in the medical field are aware of it.
"In many medical schools it is still taught that there are no treatments for tinnitus, which is quite astounding really," Dundovic said. "There have been quite a lot of advances in technologies that can treat tinnitus recently and I think they have not quite caught up with the practical education of medical students and doctors of everything that's available for the conditions. It is very difficult to fill that gap."