Tinnitus

Definition

Tinnitus is hearing ringing, buzzing, or other sounds without an external cause. Patients may experience tinnitus in one or both ears or in the head.

Description

Tinnitus affects as many as 40 million adults in the United States. It is defined as either objective or subjective. In objective tinnitus, the doctor can hear the sounds, as well as the patient. Objective tinnitus is typically caused by tumors, turbulent blood flow through malformed vessels, or by rhythmic muscular spasms. Most cases of tinnitus are subjective, which means that only the patient can hear the sounds.

Causes and symptoms

Subjective tinnitus is frequently associated with hearing loss. About 90% of patients have sensorineural hearing loss ; 5% suffer from conductive hearing loss; 5% have normal hearing. The causes of subjective tinnitus include:

• impacted ear wax
• ear infections
• hardening of the structures of the inner ear
• hearing loss related to age or excessive noise
• ototoxic medications, including aspirin, quinine, some diuretics, heavy metals, alcohol, and certain antibiotics
• meniere's syndrome
• head trauma
• systemic diseases, including syphilis, hypertension, anemia, or hypothyroidism
• tumors of the ear

Diagnosis

Diagnosis of tinnitus includes a physical examination of the patient's head and neck. The doctor will use an otoscope to examine the ears for wax, infection, or structural changes. He or she will also use a stethoscope to listen to the blood vessels in the neck. Additional tests may include the following:

Tuning fork tests

The Rinne and Weber tests are commonly used to evaluate the type and severity of hearing loss. In the Weber test, the doctor holds a tuning fork against the patient's forehead or front teeth. If the hearing loss is sensorineural, the sound radiates to the ear with better hearing; if the hearing loss is conductive, the sound will be louder in the damaged ear. In the Rinne test, the tuning fork is placed alternately on the mastoid bone (behind the ear) and in front of the ear. In conductive hearing loss, bone conduction (BC) is greater than air conduction (AC). In sensorineural hearing loss, AC is greater than BC.

Diagnostic imaging

Magnetic resonance angiography or venography (MRA and MRV) can be used to evaluate malformations of the blood vessels. Computed tomography scans (CT scans) or magnetic resonance imaging scans (MRIs) can be used to locate tumors or abnormalities of the brain stem.

Blood tests

The doctor may order a complete blood count (CBC) with specific antibody tests to rule out syphilis or immune system disorders.

Treatment

Some cases of tinnitus can be treated by removal of the underlying cause. These include surgical treatment of impacted ear wax, tumors, head injuries, or malformed blood vessels; discontinuance of ototoxic medications; and antibiotic treatment of infections.

Subjective tinnitus, especially that associated with age-related hearing loss, can be treated with hearing aids, noise generators or other masking devices, biofeedback, antidepressant medications, or lifestyle modifications (elimination of smoking, coffee, and aspirin).

Alternative treatment

A variety of alternative therapies may be helpful in the treatment of tinnitus. Dietary adjustments, including the elimination of coffee and other stimulants, may be useful, since stimulants can make tinnitus worse. In addition, reducing the amount of fat and cholesterol in the diet can help improve blood circulation to the ears. Nutritional supplementation with vitamin C, vitamin E, B vitamins, calcium, magnesium, potassium, and essential fatty acids is also recommended. Gingko (Gingko biloba ) is often suggested, since it is believed to enhance circulation to the brain. Acupuncture treatments may help decrease the level of tinnitus sounds the patient hears, and constitutional homeopathic treatment may also be effective.

Prognosis

The prognosis depends on the cause of the tinnitus and the patient's emotional response. Most patients with subjective tinnitus do not find it seriously disturbing, but about 5% have strong negative feelings. These patients are frequently helped by instruction in relaxation techniques.

Resources

BOOKS

Jackler, Robert K., and Michael J. Kaplan. "Ear, Nose, & Throat." In Current Medical Diagnosis and Treatment, 1998, edited by StephenMcPhee, et al., 37th ed. Stamford: Appleton & Lange, 1997.

KEY TERMS

Conductive hearing loss— Hearing loss caused by loss of function in the external or middle ear.

Meniere's syndrome— A disease of the inner ear, marked by recurrent episodes of loss of balance (vertigo) and roaring in the ears lasting several hours. Its cause is unknown.

Ototoxic— Damaging to the nerves controlling the senses of hearing and balance.

Sensorineural hearing loss— Hearing loss caused by damage to the nerves or parts of the inner ear governing the sense of hearing.

tinnitus refers to the sensation of sound, most often a high-pitched, noisy whistle, in one or both ears in the absence of external stimulation. Like pain, tinnitus is a very subjective phenomenon, and descriptions by sufferers tend to be in terms of a familiar sound such as the roar of the ocean or the ringing of bells. Nearly everyone experiences a mild and transient form of tinnitus. Estimates of the incidence of more severe forms vary, but around 10–14% of adults complain of tinnitus that is either prolonged or present for much of the time, and 0.5% are so affected as to have difficulty in leading a normal life.

The first written record of tinnitus appears to date back to ancient Egyptian medical documents. There are several references in Babylonian medicine to the ‘singing ear’ or the ‘whispering ear’, for which incantation of charms was advocated. Descriptions of noises in the ear and their possible causes were placed on a more scientific footing through the works of the Greek scholar Hippocrates in the fourth and fifth centuries bc and the term tinnitus originates from ancient Rome. Over the subsequent centuries, different types of tinnitus were recognized and described more completely. However, tinnitus remains one of the least understood hearing conditions, for which there is still, in many cases, no specific cure.

Many sounds are generated within the head as a result of muscular activity and by blood rushing through the cranial vessels. However, we are rarely aware of these sounds because the cochlea is shielded by the hard temporal bone. Although people with apparently normal hearing do experience tinnitus, it usually accompanies some form of hearing loss. Indeed, most people who complain to their general practitioners of deafness will also have tinnitus. Although it is often associated with disorders of the ear itself, including blockage of the ear canal by wax, otosclerosis, and Menière's disease, it is now apparent that neural activity within the brain may be a more important factor. The discovery in the late 1970s that the ear produces sounds that can be detected in the ear canal suggested a possible link between tinnitus and the activity of outer hair cells in the cochlea. However, because drugs such as aspirin both eliminate these emissions and induce tinnitus, this seems to provide an explanation in only a few cases. Moreover, tinnitus is often found in people with severe sensorineural hearing loss or following physical damage to the inner ear, which would argue against a cochlear origin for the condition.

Because of its subjective nature and the paucity of external signs associated with tinnitus, the development of animal models has been problematic. Nevertheless, studies in animals have shown that high doses of aspirin give rise to increased spontaneous activity both in the auditory nerve fibres that leave the inner ear and in the auditory midbrain. We do not yet know the mechanisms underlying central tinnitus or even which areas of the auditory pathway are responsible, but it is possible that a change in the level of inhibitory activity may be involved.

Early remedies for tinnitus usually involved the administration, either orally or into the ear canal, of a variety of substances ranging from oils to ox urine. It was observed in ancient Greece that external noise could mask buzzing in the ears and this was used therapeutically in the nineteenth century. Unless the patient is completely deaf, noise generators are still useful today as a means of providing temporary relief. By amplifying speech or environmental noise, hearing aids can also be effective in many cases. It was claimed at the beginning of the nineteenth century that electrical stimulation of the ear could be used to treat tinnitus. In a similar vein, tinnitus is often reduced after profoundly deaf patients are fitted with a cochlear implant in which sounds are transduced into electrical signals that are delivered to electrodes inserted into the cochlea of the inner ear.

In a small minority of cases tinnitus may be alleviated if the cause of the hearing loss can be treated by surgical or medical means. Because tinnitus is aggravated by stress or fatigue, the most successful treatment involves psychological counselling or some form of relaxation therapy, often in conjunction with devices that use external noise to mask the sounds that are generated within the head.

Andrew J. King

Bibliography

Shulman, A.,, Aran, J.- M.,, Feldmann, H.,, Tonndorf, J.,, and and Vernon, J. A. (1991). Tinnitus: diagnosis/treatment. Lea and Febiger, Philadelphia.
Vesterager, V. (1997). Tinnitus — investigation and management. British Medical Journal, 314, 728–31.

Tinnitus

What Is Tinnitus?

What Causes Tinnitus?

What Can a Doctor Do?

Tinnitus (ti-NY-tus) is the sense of ringing, whistling, or similar noise in the ear even when there is no external sound.

KEYWORDS

for searching the Internet and other reference sources

Auditory disorders

What Is Tinnitus?

Tinnitus is a mysterious disorder that affects as many as 50 million Americans. The sound that people with tinnitus hear is often described as a ringing, but it also can resemble whistles, sizzles, clicks, roars, or other sounds too complex to describe easily. Some people experience the noise only at certain times or notice it only when it is quiet, such as at bedtime. Others, however, live with a constant unpleasant sound.

The noise can be high-pitched like a baby’s whine or low like a rumbling train. It might sound like a continuous tone or cycle in a rhythm, often in time with the heartbeat.

What Causes Tinnitus?

Tinnitus is usually a symptom of other problems, such as too much ear-wax or an ear or nasal infection. Other causes include cardiovascular disease, tumors, jaw misalignment, anemia, and neck and head injuries. Certain medicines, such as aspirin and some antibiotics, as well as carbon monoxide and alcohol, can also cause tinnitus. Long-term exposure to loud sounds like a jet plane or loud music can lead to tinnitus.

What Can a Doctor Do?

The first thing a doctor will do is look for the cause. If it is something that can be corrected, such as removing earwax or treating an infection, the tinnitus usually will go away.

Some people must find ways to live with tinnitus. Hearing aids are a common way to help, if the cause is related to hearing loss. Sometimes the person uses a device like a hearing aid that covers the tinnitus with another sound that is less noticeable or less disturbing.

See also

Vertigo

tinnitus (ti-ny-tŭs) n. the sensation of sounds in the ears, head, or around the head in the absence of an external sound source. It can occur with any form of hearing loss or with normal hearing and is thought to be due to a misinterpretation of signals in the central auditory pathways in the brain. t. retraining therapy (TRT) a unified method of treating tinnitus, including explanation, counselling, cognitive behavioural therapy, relaxation techniques, and sound therapy (see white noise instrument).

tin·ni·tus / ˈtinitəs; tiˈnī-/ • n. Med. ringing or buzzing in the ears.

tinnitus (path.) ringing in the ears. XIX. — L. tinnītus, f. tinnīre ring, tinkle, of imit. orig.

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