Tinnitus or ringing of the ears is the perception of noise when there is no external sound made. The sound can be hissing, clicking, whistling, roaring, humming, or the common steady high pitch ringing. Thought to affect 50 million Americans, or as common as 1 in every 5 individuals, it occurs mostly after the age of 50 years but can occasionally affect children and adolescents as well. It also affects 20 to 40% of returning military personnel. Tinnitus is not a condition or disorder but rather, a symptom of an underlying condition such as
- allergic rhinitis
- ear injury
- age related hearing loss
- temporomandibular joint issues
- head or neck injuries
- blood vessel disorders
- taking certain medications
Although it can be annoying, it does not usually indicate a serious underlying issue. Tinnitus can worsen with age and can cause insomnia, depression, anxiety, poor concentration, irritability, and affecting daily routines such as work or school performance. There may also be some hearing loss. Some of the treatment and management of tinnitus includes:
- discontinuation of any ototoxic medications
- appointment with your primary care physician to check for an ear infection
- treating your temporomandibular joint problems if present
- keeping a journal of your food and observing what may aggravate it (some have claimed that caffeine reduces or aggravates their tinnitus)
- sound therapy (masking tinnitus and stress-relief)
- tinnitus retraining therapy (TRT) to retrain your auditory system to accept your tinnitus
- cognitive behavioral therapy (CBT) to help depression or anxiety due to tinnitus
- and lifestyle changes (using hearing protection such as ear mufflers in noisy environments, playing music or audio at a moderate volume, incorporating exercise, healthy eating, etcetera)
Tinnitus Changing the Brain
Dr. Fatima Husain and her research team have concluded that patients with mild tinnitus had a greater engagement in different areas of the brain when processing emotional sounds when compared to those without tinnitus. She subsequently conducted another study with her team using functional magnetic resonance imaging (MRI) to understand how the brain adapted to long term tinnitus. The team used functional MRI to observe changes of blood oxygen levels in the brain as they noticed that some patients were able to adapt to tinnitus while others do not. Through this method, the research team found that patients with lower distress due to tinnitus use an altered brain pathway to process their emotional information. Instead of using the amygdala, patients who have adapted to tinnitus use the frontal lobe for emotional processing. The frontal lobe is vital in planning, controlling impulses, and focus. From their observation, the team hypothesized that these patients were better adapted to tinnitus due to the greater activation of their frontal lobe.
Another study found that the networks in the brain change when there is tinnitus. Using MRI, the research team found that tinnitus is located in the precuneus, a small part of the brain that is connected to the dorsal attention network and default mode network. Individuals who suffer from tinnitus have a brain that is more connected to the network that holds attention (dorsal attention) and less connected to the network used when a person relaxes (default mode). Simplified, this means that people with tinnitus concentrate more and is unable to relax making them feel more tired and unfocused. These individuals are often tired and have difficulty concentrating as they are unable to be truly at rest.
Additional Studies About Tinnitus And The Brain
In a 2016 article in the Discover magazine, tinnitus occurs especially when there is injury to the nerve hairs in the ears due to drugs, loud noises, or head and neck injuries causing the neurons in the brain start firing to other frequencies and sometimes, without incoming signals. As the brain starts rewiring the feedback controls, the neurons enter a loop that produces the tinnitus sound. Neuroscientists also noticed changes across the brain using magnetoencephalography (MEG) that allows them to detect changes in the brain 100 times per second. They discovered that individuals with tinnitus have more synchronized signals from the front (dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex) and back (precuneus, posterior cingulate cortex) of the brain.
In 2004, Louis Lowry, an otolaryngologist at Thomas Jefferson University in Philadelphia made an accidental discovery where he found that the caudate and putamen (in the brain) play a significant role in tinnitus. His experience when he was young from working on a farm with a noisy tractor caused his partial hearing loss and tinnitus that affected him for 40 years. When he suffered a stroke and a computed tomography (CT) and MRI scan showed that he had a damaged caudate and putamen, he was also cured of his tinnitus with no further hearing loss. This discovery led two other doctors who tried to reproduce the same effect and subsequently reported that the tinnitus became fainter in four out of five patients.
Experimental Treatment for Tinnitus
With the available literature, Christo Pantev and his team from Germany were able to provide some relief for patients afflicted with tinnitus by rewiring their tone map. The utilized music recordings that do not contain any of the frequencies of the tinnitus their patients experienced, and the patients then listened to the edited music for approximately 12 hours each week. They found that their participants’ tinnitus was dramatically reduced and the neurons that cause tinnitus become less active. Although unsure how the edited music worked, the team speculated that the new sounds encouraged the tone map to modify its structure.
Conclusion on How Tinnitus Affects the Brain
There are many literatures that are available on how tinnitus affects the brain, but researchers are still unclear how they can apply this information into clinical practice for patients with tinnitus. What they can be sure is that the brain is affected. Unravelling the mystery of tinnitus is a race against time as the advancements made in modern life such as phones and portable music players are increasingly being used and may cause more hearing damage leading to tinnitus.