Tinnitus Treatments Result From Clinical Trials

Ever heard of tinnitus? It rings a bell. Tinnitus is a continuous or intermittent ringing in the ears that affects around one in ten Americans ^{[1, 2, 3]}. It sounds like that high-pitched ringing you might hear after a loud concert. Tinnitus is poorly understood ^[3]. Non-hispanic White Americans and those aged 60-69 are at an increased risk of tinnitus ^{[2, 3]}. There are no cures for tinnitus, so avoiding risks is critical ^{[2, 4]}. The biggest avoidable risk factors for tinnitus are ^{[2, 3, 4]}:

• Loud-noise exposure
• Some medications
• Infections
• Ear and head injury

There is also some evidence that smoking, heart disease, and metabolic disorders like diabetes may increase the risk of tinnitus ^{[2, 3]}. Tinnitus can be annoying and cause problems in everyday life, including disruptions to hearing, thinking, sleep, and concentration ^[1]. These disruptions may reduce quality of life, cause anxiety and depression, and hinder people’s ability to work ^[1].

Researchers think tinnitus is a result of the body responding incorrectly to hearing loss ^[5]. Scientists don’t know exactly which parts of the brain cause tinnitus, but they have chimed in with a few possible areas. The cochlea is the part of the inner ear where outer and inner hair cells turn sound into electrical signals in the brain ^{[3, 5]}. The outer hair cells are more vulnerable to damage and may take months to repair, if ever ^[3]. Without outer hair cells, the inner hair cells may fire even without sound, causing a ringing noise ^{[3, 5]}. Other parts of the brain may cause tinnitus in a similar manner. When hearing loss causes decreased nerve activity from the ears, parts of the brain that amplify and/or interpret the signals may overcompensate in an attempt to “boost the signal,” causing us to experience sound that isn’t there ^{[3, 5]}.

Science has not yet discovered a cure for tinnitus, so all treatments aim to lessen symptoms. This is in spite of numerous clinical studies which have looked for drug, behavioral, and device-based solutions. Pharmacological clinical trials have investigated psychoactive drugs (like NDMA receptor agonists), nitrous oxide, magnesium, and zinc in hundreds of heroic patients, but the drugs fail to outperform placebo or produce significant clinical benefits ^{[6, 7]}. Behavioral studies have produced much more favorable results, with cognitive behavioral therapy showing enough promise to become the standard of care for tinnitus treatment ^{[4, 7]}. Cognitive behavior therapy is a type of talk psychotherapy in the presence of a trained expert to help lower symptoms ^[8]. Recent clinical trials have found promising results with internet-based cognitive behavior therapy, making it easier to access for some people ^[8]. Finally, clinical researchers have been investigating various devices to help with tinnitus ^[7]. Investigators have sounded out solutions ranging from hearing aids and nerve stimulation devices to repetitive transcranial magnetic stimulation - technology that directly stimulates specific parts of the brain without surgery ^[7]. The first (and so far only) device to be approved by the FDA is the Lenire, from a company called Neuromod Devices, which matches an electrical signal on the tongue with headphone-delivered tones in an attempt to retrain the brain ^[9]. With the help of clinical trials, this success might also ring true for other tinnitus research!

Look for tinnitus research studies enrolling near you at clincaltrials.gov

Creative Director Benton Lowey-Ball, BS, BFA

References:

[1] Bhatt, J. M., Lin, H. W., & Bhattacharyya, N. (2016). Prevalence, severity, exposures, and treatment patterns of tinnitus in the United States. JAMA Otolaryngology–Head & Neck Surgery, 142(10), 959-965. https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2533660

[2] Shargorodsky, J., Curhan, G. C., & Farwell, W. R. (2010). Prevalence and characteristics of tinnitus among US adults. The American journal of medicine, 123(8), 711-718. https://pubmed.ncbi.nlm.nih.gov/30073285/

[3] Makar, S. K. (2021). Etiology and pathophysiology of tinnitus: a systematic review. The International Tinnitus Journal, 25(1), 76-86. https://www.tinnitusjournal.com/articles/etiology-and-pathophysiology-of-tinnitus--a-systematic-review-16383.html

[4] Dalrymple, S. N., Lewis, S. H., & Philman, S. (2021). Tinnitus: diagnosis and management. American family physician, 103(11), 663-671. https://www.aafp.org/pubs/afp/issues/2021/0601/p663.html

[5] Shore, S. E., & Wu, C. (2019). Mechanisms of noise-induced tinnitus: insights from cellular studies. Neuron, 103(1), 8-20. https://www.cell.com/neuron/fulltext/S0896-6273(19)30433-7

[6] Staecker, H., Morelock, M., Kramer, T., Chrbolka, P., Ahn, J. H., & Meyer, T. (2017). Safety of repeated-dose intratympanic injections with AM-101 in acute inner ear tinnitus. Otolaryngology–Head and Neck Surgery, 157(3), 478-487. https://pubmed.ncbi.nlm.nih.gov/28608739/

[7] National Library of Medicine. (n.d.). ClinicalTrials.gov. U.S.Department of Health and Human Services. [Website. Accessed 24 March, 2024]. https://clinicaltrials.gov/search?cond=Tinnitus&aggFilters=results:with,status:com&locStr=United%20States&country=United%20States

[8] Beukes, E. W., Andersson, G., & Manchaiah, V. (2021). Patient uptake, experiences, and process evaluation of a randomized controlled trial of internet-based cognitive behavioral therapy for tinnitus in the United States. Frontiers in medicine, 8, 771646. https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.771646/full

[9] Conlon, B., Hamilton, C., Meade, E., Leong, S. L., O Connor, C., Langguth, B., ... & Lim, H. H. (2022). Different bimodal neuromodulation settings reduce tinnitus symptoms in a large randomized trial. Scientific reports, 12(1), 1-18. https://www.nature.com/articles/s41598-022-13875-x