Join us for our 24th episode as we dive into the world of tinnitus! Discover the ins and outs of this perplexing condition, from patient workup and differential diagnoses to effective management strategies and clinical pearls. Tune in for an ear-opening experience!

Show Notes

Introduction 

Hey everyone and welcome to The Oto Approach, a podcast created by medical students for medical students, to teach you about all things otolaryngology. I'm your host, Jessica, and today we're going to talk about tinnitus. Tag along for a discussion on this interesting topic!

Prevalence

Tinnitus is a common condition involving a ringing, buzzing, or abnormal sound perceived in the ears without any external source. Globally, it is estimated that 14.4% of all adults and 23.6% of adults over 65 years old have been diagnosed with tinnitus at some point in their lives, with approximately 9.8% of the population suffering from chronic persistent tinnitus [1].

Etiology

The etiology of tinnitus is complex, multifactorial, and not completely understood. It is believed that tinnitus is predominantly associated with hearing loss, with damage to the auditory system often contributing to the development of this condition [2]. Exposure to loud noises, as can occur in the workplace or recreational contexts, is a common cause of hearing loss and subsequently tinnitus [3]. Other contributors include age-related hearing impairment, ear or ear-related conditions like chronic otitis media, inflammatory ear disease, vestibular migraine, and TMJ disorders.  Medications such as anti-inflammatories and ototoxic drugs like aminoglycoside antibiotics, platinum-based chemotherapies, and loop diuretics may also result in tinnitus and hearing loss [4]. Additionally, psychiatric comorbidities like anxiety and depression are believed to have a bidirectional association with tinnitus, contributing to the exacerbation of tinnitus symptoms, while also becoming intensified by the experience of tinnitus [6]. The exact mechanisms of these relationships remain under investigation, and the cause in most cases of tinnitus are unknown.  Some anecdotal hypotheses have emerged proposing that these indeterminate cases may be influenced by hearing loss in ranges outside of those measured in traditional audiometry, particularly when hearing loss occurs in higher frequency ranges.

Anatomy

Several regions of the auditory pathway are believed to be involved in the experience of tinnitus. In the peripheral auditory system, dysfunction or damage of hair cells in the cochlea can result in the generation of abnormal electrical activity in the cochlear nerve. These signals are then transmitted to the central auditory system in the same way that other sounds are, resulting in the experience of hearing noises that aren’t actually there [7,8].

Additionally, in the central auditory system, several structures such as the cochlear nucleus, inferior colliculus, and auditory cortex also contribute to tinnitus signals. Some evidence suggests that the generation and maintenance of tinnitus in these structures can occur due to increased neural activity, synchronized neuronal firing, and maladaptive plasticity in these regions [7,8]. This maladaptive neural plasticity is particularly interesting, as it is believed to involve neural changes which increase the spontaneous firing and synchronization of central auditory neurons, again leading to the perception of subjective sounds [9]. Future research aims to further understand these various contributors.

It is important to note that a crucial consideration when determining the anatomy and pathophysiology of a tinnitus presentation at this stage, is to differentiate whether it is pulsatile (ie: pulse-synchronous) or not, as this will largely influence the subsequent diagnostic algorithm and treatment.  This episode of the podcast will not discuss diagnosis and management of pulsatile tinnitus.

Patient Workup & Investigations

To evaluate a patient with tinnitus, a thorough medical history should be taken to aid in identifying specific triggers and associated symptoms, as well as other relevant medical conditions that may be contributing to tinnitus.  

A full-body physical exam should be conducted, with a focus on the ears, to identify potential underlying causes and/or contributing factors. An otoscopic examination of the ear is key in identifying any gross abnormalities in the middle ear that may be causing or contributing to tinnitus.  Unfortunately, the physical examination is often completely normal.   

An audiogram is critical in assessing the patient's hearing to identify the presence of any hearing loss – a key contributor to the development of tinnitus.  An audiogram in a tinnitus patient is like an ECG in a chest pain patient; it should be mandatory and the first, and often only, investigation required.

Beyond the audiogram, it is important to also consider and evaluate other concurrent symptoms that may be occurring alongside the tinnitus. These other symptoms may indicate a larger disease process of which the tinnitus is perhaps the most bothersome, but not the most important, symptom.

History

A thorough history can play a key role in helping to determine if there is an identifiable underlying cause for the tinnitus, but a firm diagnosis of the source of the tinnitus is often not possible.  A comprehensive history of tinnitus involves gathering information about the onset, duration, timing, consistency, and characteristics of the sounds heard. If the tinnitus is pulsatile in nature then the diagnostic workup and management is completely different, and not the topic of this episode. Emphasis should be on eliciting associated symptoms like hearing loss, ear pain, or vertigo, as well as the patient's medical and medication history. It is particularly important to inquire about certain factors that contribute to tinnitus, including bruxism and other TMJ disorders, noise exposure history, ototoxic exposures, headaches and migraines, and chronic neck disorders [10]. It is also considered good practice to perform a psychological assessment of the patient to determine if psychological or emotional factors may be contributing to their condition, while also evaluating the impact of the condition on their well-being [11, 12].

Physical

It is important to perform a comprehensive evaluation of the patient's ears, head and neck.  The ear exam generally includes an inspection of the external ear for any gross abnormalities, paying particular attention to any signs of infection. An extensive otoscopic examination should also be performed to visualize the ear canal for infection or wax buildup, as well as to investigate the tympanic membrane for any signs of perforation, inflammation, or other abnormalities. A broader examination of the head, neck, teeth, and oral cavity is useful in evaluating the structures surrounding the ears for any contributing influences, such as TMJ pain and tenderness or crepitus, muscle tension or dental abnormalities.

Differential Diagnosis

Tinnitus is unique from our other episode topics in that it is both a symptom and a diagnosis in itself. As such, it is either classifiable as a tinnitus presentation or it is not. Given its symptomatic nature, there is no clear role for a differential diagnosis, albeit many of the conditions mentioned previously must be considered as potential causes for tinnitus.

Treatment

It is important to acknowledge that there is unfortunately no cure for tinnitus at present. That said, there are various treatment options aimed at decreasing the intensity of tinnitus, increasing patient tolerance of tinnitus, decreasing tinnitus distress, and improving patients’ quality of life. While some patients’ tinnitus resolves completely, most do not, and it is an important aspect of treatment that the patient realizes that the goal is to get it to a manageable level where it no longer bothers them. 

One common and easily applied approach is sound therapy. This involves the use of external sounds (white noise, music, or other noises) to mask or decrease the patient’s perception of tinnitus. This noise can be delivered in a variety of ways, such as the use of hearing aids to amplify day-to-day sounds, bedside sound or white noise machines, car radios, or a variety of novel smartphone applications [13]. If the brain is busy listening to other things, it does not listen to the tinnitus.  By and large, most patients find their tinnitus improves significantly from using masking techniques only, as well as a general cognitive approach to ignore the tinnitus and not treat it as something noteworthy or important in their lives. 

To this end, there is significant evidence supporting the use of cognitive behavioural therapy (CBT) as a strategy to manage tinnitus-related anxiety and emotional distress, particularly in helping individuals reframe their interpretation of symptoms [14]. There is also some debate over the efficacy of using other treatment modalities for a similar goal, such as acupuncture, medication, and transcranial magnetic stimulation, all of which require further investigation and augmented evidence [15,16]. While there is no good evidence supporting the use of antidepressants in tinnitus as a whole, in select patients suffering from significant anxiety, either about tinnitus or other aspects of their lives, these medications may help. 

In most cases of tinnitus, the management plan combines several approaches to address a patient’s personal needs and preferences, all with the overarching goal of reducing the negative impact of tinnitus on their daily lives.

Prognosis

There is a wide range of prognoses for tinnitus depending on its underlying cause and severity. When tinnitus is caused by hearing loss or exposure to loud noises, the prognosis is often chronic and the symptoms may persist throughout a person's life [17]. For others, tinnitus may improve or even resolve spontaneously over time [10,17]. As mentioned previously, however, tinnitus management is largely aimed at improving quality of life as opposed to eliminating symptoms entirely, thus making symptom minimization a more realistic goal at the time of diagnosis than remission itself.

Clinical Pearls

- Tinnitus is an extremely common condition involving a ringing, buzzing, or abnormal sound perceived in the ears without any external source.

- Many cases of tinnitus are associated with hearing loss, particularly from workplace or recreational exposure to loud noises, and as such, an audiogram is a mandatory test in tinnitus, and often the only test needed. That said, s ome tinnitus may result from hearing loss outside of the ranges tested in traditional audiometry.

- There is currently no cure for tinnitus, although some cases may resolve spontaneously.

- The treatment of tinnitus is focused on symptom alleviation, with sound therapy being a common first-line treatment. Its administration can vary from the use of hearing aids to white noise machines, or any other means of providing external auditory stimulation.

Closing remarks 

Thank you to Jessica Maher for developing this script, and Dr. Alexander Moise and Dr. Darren Tse for editing this script.

We would like to extend our sincerest thanks to the Saint John Regional Hospital Department of Surgery within the Horizon Health Network for their generous support.

Thank you so much for listening to our podcast! We hope you’ll tune in to our next episode! Please head to our website at www.theotoapproach.com for our show notes, and to sign up for our newsletter to stay up to date with our latest episodes.

References:

[1] Jarach, C. M., Lugo, A., Scala, M., et al. (2022). Global prevalence and incidence of tinnitus: A systematic review and meta-analysis. JAMA Neurology, 79(9), 888-900. https://doi.org/10.1001/jamaneurol.2022.2189

[2] Shargorodsky J, Curhan GC, Farwell WR. Prevalence and characteristics of tinnitus among US adults. Am J Med. 2010;123(8):711-718. doi:10.1016/j.amjmed.2010.02.015

[3] Nondahl DM, Cruickshanks KJ, Dalton DS, et al. The impact of tinnitus on quality of life in older adults. J Am Acad Audiol. 2007;18(3):257-266. doi:10.3766/jaaa.18.3.7

[4] Baguley D, McFerran D, Hall D. Tinnitus. The Lancet. 2013;382(9904):1600-1607. doi:10.1016/s0140-6736(13)60142-7

[5] Langguth B, Kreuzer PM, Kleinjung T, De Ridder D. Tinnitus: Causes and clinical management. The Lancet Neurology. 2013;12(9):920-930. doi:10.1016/s1474-4422(13)70160-1

[6] Song Z, Wu Y, Tang D, Lu X, Qiao L, Wang J, and Li H. Tinnitus Is Associated With Extended High-frequency Hearing Loss and Hidden High-frequency Damage in Young Patients. Otology and Neurotology. 2021;42(3):377-383. doi: 10.1097/MAO.0000000000002983

[7] Eggermont, J. J. (2017). Pathophysiology of tinnitus. Progress in brain research, 249, 101-121.

[8] Adjamian, P., Sereda, M., & Hall, D. A. (2009). The mechanisms of tinnitus: perspectives from human functional neuroimaging. Hearing research, 253(1-2), 15-31.

[9] Shore, S. E., Roberts, L. E., & Langguth, B. (2016). Maladaptive plasticity in tinnitus–triggers, mechanisms and treatment. Nature Reviews Neurology, 12(3), 150-160. https://doi.org/10.1038/nrneurol.2016.12

[10] Baguley, D., McFerran, D., & Hall, D. (2013). Tinnitus. The Lancet, 382(9904), 1600-1607.

[11] National Guideline Centre (UK). Evidence review for assessing psychological impact: Tinnitus: assessment and management: Evidence review F. London: National Institute for Health and Care Excellence (NICE); 2020 Mar. (NICE Guideline, No. 155.) Available from: https://www.ncbi.nlm.nih.gov/books/NBK557038/

[12] Langguth, B., Kreuzer, P. M., Kleinjung, T., & De Ridder, D. (2013). Tinnitus: Causes and clinical management. The Lancet Neurology, 12(9), 920-930.

[13] Heeren, A., Maurage, P., Perrot, X., & Londero, A. (2014). Benefit of sound therapy for tinnitus management: a systematic review and meta-analysis. Frontiers in Neuroscience, 8, 1-12.

[14] Martinez-Devesa, P., Perera, R., Theodoulou, M., & Waddell, A. (2010). Cognitive behavioural therapy for tinnitus. Cochrane Database of Systematic Reviews, 9, CD005233.

[15] Hobson, J., Chisholm, E., El Refaie, A., Sound Therapy Study Group, & Meerton, L. (2012). Sound therapy (masking) in the management of tinnitus in adults. Cochrane Database of Systematic Reviews, 11, CD006371.

[16] Hoare, D. J., Kowalkowski, V., Sheldrake, J. B., & Hall, D. A. (2014). Homeopathic remedies for tinnitus: a systematic review. Homeopathy, 103(2), 97-103.

[17] Dawes, P., Cruickshanks, K. J., Marsden, A., Moore, D. R., Munro, K., & Wilson, M. J. (2014). The prevalence of phantom auditory sensations: Results from a nationally representative survey. Otology & Neurotology, 35(3), 472-477.