A ringing or hissing sound heard within the ear, which may arise from almost any disorder of the ear or its nerve supply. When the cause is simple, such as excessive wax in the external ear, the condition is easily remedied; in other cases, the disorder is usually intractable.
TinnitusClassifications and external resources
| ICD-10 | H93.1 |
|---|---|
| ICD-9 | 388.3 |
Tinnitus (ti-NIGHT-us or TIN-i-tus) is the perception of sound in the absence of a corresponding external sound. Tinnitus is the Latin word for "ringing", and usually it is described as a ringing noise, but in some patients it takes the form of a buzzing, hissing, humming, or whistling sound, ticking, clicking, roaring, "crickets," tunes, songs, or beeping.
Tinnitus is not itself a disease, but an unwelcome symptom resulting from a range of underlying causes, including ear infections, foreign objects or wax in the ear, and injury from loud noises, as may have been experienced by war veterans (bombardments, shelling, etc.). (see noise health effects)
Because tinnitus is often defined as a subjective phenomenon, it is difficult to measure using objective tests, such as by comparison to noise of known frequency and intensity, as in an audiometric test.
Objective tinnitus
In a minority of cases, a clinician can perceive an actual sound (e.g., a bruit) emanating from the patient's ears. Objective tinnitus can arise from muscle spasms that cause clicks or crackling around the middle ear. Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow or increased blood turbulence near the ear (such as from atherosclerosis or venous hum), but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear.
Causes of subjective tinnitus
Tinnitus can have many different causes, but most commonly results from otologic disorders - the same conditions that cause hearing loss. Ototoxic drugs can cause tinnitus either secondary to hearing loss or without hearing loss, and may increase the damage done by exposure to loud noise, even at doses that are not in themselves ototoxic.
Causes of tinnitus include:
Otologic problems and hearing loss: conductive hearing loss external ear infection cerumen (earwax) impaction middle ear effusion sensorineural hearing loss excessive or loud noise presbycusis (age-associated hearing loss) Meniere's disease acoustic neuroma ototoxic medications analgesics: aspirin nonsteroidal anti-inflammatory drugs antibiotics: aminoglycosides chloramphenicol erythromycin tetracycline vancomycin chemotherapy drugs: bleomycin cisplatin mechlorethamine methotrexate vincristine loop diuretics: bumetanide ethacrynic acid furosemide others: chloroquine quinine mercury lead neurologic disorders: multiple sclerosis head injury skull fracture closed head injury whiplash injury temporomandibular joint disorder metabolic disorders: thyroid disorder hyperlipidemia vitamin B12 deficiency psychogenic disorders: depression anxiety other disorders: fibromyalgiaMechanisms of subjective tinnitus
The inner ear contains thousands of minute hairs which vibrate in response to sound waves. In tinnitus, they may falsely relay information at a certain frequency that an externally audible sound is present, when it is not.
The mechanisms of subjective tinnitus are often obscure. While it is not surprising that direct trauma to the inner ear can cause tinnitus, other apparent causes (e.g., TMJ and dental disorders) are difficult to explain. Recent research has proposed that there are two distinct categories of subjective tinnitus: otic tinnitus, caused by disorders of the inner ear or the acoustic nerve; and somatic tinnitus, caused by disorders outside the ear and nerve, but still within the head or neck. It is further hypothesized that somatic tinnitus may be due to "central crosstalk" within the brain, as certain head and neck nerves enter the brain near regions known to be involved in hearing.
Prevention
Because tinnitus and hearing loss can be permanent conditions, precautionary measures are advisable. For musicians and DJs, special musicians' earplugs can lower the volume of the music without distorting the sound and can prevent tinnitus from developing in later years.
Tinnitus treatment
There are many treatments that are effective for tinnitus resulting from a particular cause, but none that are effective in every case. Electrical stimulation Transcranial magnetic stimulation or transcranial direct current stimulation Transcutaneous electrical nerve stimulation Direct stimulation of auditory cortex by implanted electrodes Surgery Repair of perilymph fistula External sound Tinnitus masking (white noise) Tinnitus retraining therapy Auditive stimulation therapy (music therapy) Compensation for lost frequencies by use of a hearing aid. Ultrasonic bone-conduction external acoustic stimulation Avoidance of outside noise (exogenous tinnitus) Psychological Cognitive behavior therapy
A Tinnitus FAQ lists many other potential therapies.
Although there are no specific cures for tinnitus, anything that brings the person out of the "fight or flight" stress response helps symptoms recede over a period of time. Chronic tinnitus can be quite stressful psychologically, as it distracts the affected individual from mental tasks and interferes with sleep, particularly when there is no external sound. Additional steps in reducing the impact of tinnitus on adverse health consequences include: a review of medications that may have tinnitus as a side affect;
A newer approach to tinnitus treatment, developed by The Ear Research Foundation, involves clinical psychology. The role of the psychologist, as a vital member of the treatment team, is to assist patients in “retraining their brain”, so they can deal with their tinnitus and minimize the difficulties it creates in their lives.
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