Tinnitus - Natural Overview

What is it?

Tinnitus is the medical term used to describe “ringing in the ears.” Tinnitus is defined as the conscious perception of an auditory sensation in the absence of an external stimulus. Tinnitus is a rather common symptom that can be quite persistent and therefore disruptive to daily activities and quality of life. The extent of debility, however, can vary from one person to the next. For example, some may only notice tinnitus in a quiet room, while others may have difficulty functioning on a day-to-day basis due to the severity of their condition.

Tinnitus can subjectively present as hissing, sizzling, and/or ringing noises. In more complex cases, affected individuals may also report hearing music and voices. It is important to see a medical professional for further evaluation if auditory hallucinations involving music and/or voices are occurring, as a more serious condition may need to be addressed.^[1] Tinnitus can be subjective or objective; pulsatile or rhythmical in nature. Subjective refers to sensations or stimuli where a source cannot be identified (an absence of external acoustic stimulation). Most reported cases of tinnitus are subjective. Subjective tinnitus can be estimated using a visual analogue scale (VAS) or a numeric rating scale (NRS) for intensity. In comparison, objective tinnitus exists when an external source can be identified. Matching or masking methods are used to quantify tinnitus objectively. Matching is achieved by offering different tones to the patient and asking which frequency an intensity best fitting the tinnitus. Masking, which involves the estimation of the minimum noise level required to mask tinnitus, is more reliable for assessing loudness.^[2] Pulsatile tinnitus refers to a rhythmical pattern similar to that of the heartbeat.^[3] This type of tinnitus comes and goes in pulses, suggesting it may involve myoclonus of the middle ear muscles or be of vascular origin.

Meanwhile, tinnitus can be constant or intermittent for a number of reasons. It can be localized to one ear, both ears, or described as originating from within the head.^[1] The extent to which tinnitus is perceived by an individual varies: there is a poor correlation between the intensity of tinnitus (as determined by matching or masking techniques) and the degree of annoyance that it creates. This finding suggests that additional factors such as emotion and attention are also important in determining quality of life.^[2]

Epidemiology

Studies reveal that tinnitus is prevalent among 10–15% of the adult population,^[1] with a higher prevalence of tinnitus among men. The reason for higher prevalence among men may be due to the higher prevalence of hearing loss in men, often due to factors associated with occupation.^[4] Meanwhile, tinnitus appears to become increasingly prevalent and troublesome in older age groups,^[1] peaking at 14.3% for those between 60 and 69 years of age.^[6] Tinnitus impairs the quality of life of about 1% of the general population.^[2] In 10–20% of the population, a cause for tinnitus cannot be found, and so it is referred to as “idiopathic”.^[3]

Risk Factors

Ongoing exposure to significant levels of noise is a risk factor for the development of tinnitus. Additional risk factors include hearing loss, wax buildup, ototoxic medication, head injury, anxiety, and depression.

The primary risk factor is hearing loss: people who report high levels of both occupational and recreational noise exposure are more likely to develop tinnitus.^[1] A variety of other risk factors are being investigated, including obesity, smoking, alcohol consumption, temporomandibular joint problems, cervical spine pathology ^[5], history of arthritis, and hypertension. Some studies also suggest the possibility of a genetic predisposition. Tinnitus can be a symptom of several otological diseases, such as Ménière’s disease, otosclerosis, and acoustic neuroma.^[1]

Pathophysiology

Tinnitus used to be understood as an inner-ear disease. However, further investigation was required after patients had their acoustic nerve transected and the tinnitus did not cease to occur. Since then, it has been thought that the central nervous system is ultimately responsible for the pathophysiology of chronic tinnitus. Tinnitus results from augmented stimulation all the way along the central auditory pathway, which arises as a compensatory reaction to the partial hearing loss experienced in most cases.^[5] Tinnitus can originate at any location along the auditory pathway, and the mechanisms believed to cause it include injured cochlear cells discharging repetitively or undergoing spontaneous destruction/death (also known as apoptosis), spontaneous activity in auditory nerve fibers, hyperactivity of auditory nuclei in the brain stem, and reduction in the normal suppressive activity of the central auditory cortex or peripheral auditory nerve activity.^[6] A decrease in inhibition and/or increase in excitation in the auditory pathway may lead to an imbalance that can cause neural hyperexcitability in these regions leading to the perception of phantom sounds in tinnitus.^[2] Meanwhile, there appear to be common pathways involved in the pathophysiology of tinnitus and depression. Neuroendocrine studies revealed that there are alterations in the hypothalamic-pituitary-adrenal axis (HPA-axis) in depression as well as tinnitus. These findings suggest that it is not by chance that one who is depressed may also have tinnitus.^[7]

Diagnosis

No objective test is available for most presentations. Diagnosis is made from a proper assessment that involves taking a thorough medical history and performing relevant physical examinations. Physical examination should include evaluation of the ears (especially the external ear canal and tympanic membrane), cranial nerves, auscultation (over the neck, periauricular area, orbits, and mastoid), compression of the jugular vein, and testing for sensorineural or conductive hearing loss.^[6] Audiometry with tympanometry is also helpful, and neuroimaging or assessment of vestibular function may be required for some patients.^[8] Tinnitus can be classified according to the severity of symptoms experienced:^[5]

Treatment

There is currently no treatment that can cure tinnitus; however, treatments are geared toward improving the symptoms of the condition by targeting different pathways. The most frequently used therapies consist of auditory stimulation and cognitive behavioral therapy, which aim to improve habituation and the ability to cope with the condition.^[2] The following natural therapies may provide symptomatic relief:

• Gingko biloba extract was found to be superior to placebo in the treatment of tinnitus. Gingko contains bioactive flavonoids and terpenes with vasoactive and antioxidant properties. Eight randomized, placebo-controlled trials of the standardized extract showed statistically significant superiority of the treatment over placebo. A change in tinnitus volume and intensity was observed, as well as a change in overall severity.^[3]
• Niacin (both IV and oral administration) is a vasodilator, and thus it is thought to normalize blood flow through the labyrinth of the ear and osmotic pressures. Niacin was able to diminish the pitch and loudness of tinnitus, as assessed with audiological tests.^[6]
• Vitamin B1 appears to have a stabilizing effect upon the nervous system, especially the inner ear. Through this proposed mechanism, vitamin B1 is thought to relieve tinnitus.^[6]
• Folic acid, like vitamin B1, might have a stabilizing effect upon the nervous system. There have been anecdotal reports that folic acid also relieves tinnitus.^[6]
• Vitamin B12 serum levels were measured in those with chronic tinnitus and noise-induced hearing loss. Vitamin B12 levels were substantially lower in approximately half of the 113 patients with reported tinnitus and noise-induced hearing loss. Improvements were noted in tinnitus and associated complaints following vitamin B12 replacement therapy.^[6]
• Ipriflavone is an isoflavone synthesized from soy. In a randomized study evaluating the effects of ipriflavone in patients with tinnitus due to otosclerosis, patients took either the isoflavone or a placebo pre- and postoperatively for three months. Both interventions were combined with stapedectomy. In the preoperative period, 44% of patients taking the ipriflavone reported they no longer experienced tinnitus (and only one patient in the placebo group experienced relief). Meanwhile, in the postoperative period, all patients taking ipriflavone experienced relief of their tinnitus (and only 50% of the placebo group). The mechanism of action for tinnitus in this particular case remains unknown.^[6]

Conclusion

Chronic tinnitus is a common disorder in the general population, and some patients suffer from severe impairment in their quality of life. Tinnitus is difficult to treat, as it has multiple possible causes and comorbidities; therefore, a thorough case history, physical examination, and diagnostic workup are essential for proper evaluation and treatment.^[5] No single treatment can help or cure tinnitus; therefore, current methods aim to improve symptoms and quality of life.^[6] It is important to book an appointment with a naturopathic doctor before experimenting or undergoing treatment with the above-mentioned therapies. A proper assessment should be made prior to starting any intervention. A naturopathic doctor will help ensure that there aren’t any potentially harmful interactions between current medications and natural therapies.