Paquette et al (2017) reported a prospective study of 166 patients who had brain surgery involving removal of the medial temporal lobe. The prevalence of tinnitus increased from approximately from 10 to 20% post surgery. This study did not include a control -- a natural question would be -- suppose a different part of the brain were removed. One would also think that drilling of the skull from any source might increase tinnitus. We are presently dubious that the medial temporal lobe suppresses tinnitus.
Tinnitus is a non-curable, invisible and debilitating hearing disorder that can take on many different forms – ringing, hissing, buzzing, and even the sound of crickets. Almost everyone has experienced brief periods of mild tinnitus, but for many, this sound can be permanent. Over 360,000 Canadians report suffering from chronic tinnitus, and almost half of those are severely affected.1 In the US, over 16 million tinnitus sufferers seek treatment every year.2 Tinnitus is the number one disability claim for US veterans3 and has also become the top disability claim for current and former male RCMP members.4 This persistent sound can have a serious impact on quality of life; leading to sleep deprivation, depression, anxiety, and even suicide. What adds to the challenges faced by tinnitus sufferers is a lack of knowledge, support and options available to them. Unfortunately, there are currently too few health care professionals providing services to tinnitus sufferers who are seeking ways to manage their tinnitus. Unfortunately, the phrase “learn to live with it” is still heard far too often by those that seek help for tinnitus.
An ultrasound is another test that may be used to aid in the diagnosis of tinnitus. An ultrasound uses reflected high-frequency sound waves and their echoes to create images of structures within the body. An ultrasound can reveal how blood flows within vessels, but is only useful for accessible vessels. It is not helpful for blood vessels within the skull.
When we hear, sound waves travel through the ear into the cochlea, our hearing organ in the inner ear. The cochlea is lined with thousands of tiny sound-sensing cells called hair cells. These hair cells change the sound waves into electrical signals. The hearing nerve then sends these electrical signals to the hearing part of the brain, which analyses them and recognises them as sound.
The exact biological process by which hearing loss is associated with tinnitus is still being investigated by researchers. However, we do know that the loss of certain sound frequencies leads to specific changes in how the brain processes sound. In short, as the brain receives less external stimuli around a specific frequency, it begins to adapt and change. Tinnitus may be the brain’s way of filling in the missing sound frequencies it no longer receives from the auditory system.
To keep the brain activated and aware, Kilgard’s therapy involves stimulating the vagus nerve, which is actually a pair of nerves that runs inside the neck and into the brain. “All the stuff you brains learns about your body — it all comes in through the vagus nerve,” he says. “We trick the brain into thinking it’s learning something important by stimulating this nerve in the neck.”
While tinnitus is as varied as its causes, it can be grouped into two categories: tonal and non-tonal. Tonal tinnitus is more common and describes the perception of a near-continuous sound or overlapping sounds with a well-defined frequency (e.g., whistling, ringing, buzzing). Non-tonal forms of tinnitus include humming, clicking, crackling, and rumbling.
Psychological research has looked at the tinnitus distress reaction (TDR) to account for differences in tinnitus severity. These findings suggest that at the initial perception of tinnitus, conditioning links tinnitus with negative emotions, such as fear and anxiety from unpleasant stimuli at the time. This enhances activity in the limbic system and autonomic nervous system, thus increasing tinnitus awareness and annoyance.
Various techniques can help make tinnitus tolerable, although the ability to tolerate it varies from person to person. Many people find that background sound helps mask the tinnitus and helps them fall asleep. Some people play background music. Other people use a tinnitus masker, which is a device worn like a hearing aid that produces a constant level of neutral sounds. For the profoundly deaf, an implant in the cochlea (the organ of hearing) may reduce tinnitus but is only done for people with severe to profound hearing loss in both ears. If these standard techniques are not helpful, people may want to seek treatment in clinics that specialize in the treatment of tinnitus.
Loud noise exposure: Being exposed to occupational loud noise on a regular basis from heavy equipment, chain saws or firearms is a common cause of tinnitus. However, even if you don’t work in a noisy environment, you can still suffer the effects of noise exposure by listening to loud music through headphones, attending live music performances frequently and engaging in noisy hobbies.