Recent research finds ringing in the ears (tinnitus) caused by the adverse effects of stress and not by the ears. Therefore, reducing stress can eliminate tinnitus.
A global research effort involving investigators from the University at Buffalo; Southeast University in Nanjing, China; and Dalhousie University in Nova Scotia, Canada, has found that tinnitus (ringing in the ears) is not caused by the ear itself, but by a neural network that is involved with auditory processing. They also found that this neural network can become ‘stimulated’ by traumatic stress, including the stress overly apprehensive behavior can cause. Consequently, anxiety and stress are common causes of tinnitus rather than something caused by the ear or inner ear, as previously thought.
Up until recently, tinnitus was largely a mystery, a phantom sound heard in the absence of actual sound. Tinnitus patients “hear” ringing, buzzing or hissing in their ears much like an amputee might “feel” pain in a missing limb. It is a symptom, not a disease, and though exposure to loud noise may cause it, most cases had no apparent trigger.
Existing treatments, were unreliable, either not working at all or varying greatly in effectiveness for those who report some relief.
Until the mid-1990s, tinnitus was thought to be centered in the ear, but patients who lost their hearing on one side after a surgical tumor removal unrelated to the condition reported still hearing a ringing — in their deaf ear.
“This changed the thinking in the field,” says Richard Salvi, director of UB’s Center for Hearing and Deafness, and one of the study’s authors. “Having severed the neural connection between the ear and the brain, it’s impossible for the phantom sound to be generated in the ear. It has to be generated in the brain.”
Though it’s not known yet exactly where and how tinnitus occurs in the brain, Salvi says their functional MRI studies show the abnormal activity underlying tinnitus and hyperacusis isn’t confined to a specific brain location, but actually involves a neural network.
Unlike traditional MRIs, which show only structure, functional MRIs show what parts of the structure are active at a given time while functional connectivity MRI reveals how one part of the brain interacts with other regions, much like partners would interact on a dance floor, explains Yu-Chen Chen, a radiologist at Southeast University and one of the study’s co-authors.
The researchers induced tinnitus in rats by administering the active ingredient in aspirin, which has long been known to produce tinnitus and hyperacusis symptoms in humans.