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Tinnitus is a noise in the ears; it is experienced by 10 to 15% of the population. Subjective tinnitus is perception of sound in the absence of an acoustic stimulus and is heard only by the patient. Objective tinnitus results from noise generated by vascular tissue near the ear and, in some cases, is heard by the examiner.
Tinnitus may be described as buzzing, ringing, roaring, whistling, or hissing and is sometimes variable and complex. It may be intermittent, continuous, or pulsatile (synchronous with the heartbeat). Continuous tinnitus is at best annoying and is often quite distressing. Some patients adapt to its presence better than others; depression occasionally results. Stress generally exacerbates tinnitus.
Etiology
Subjective tinnitus may occur with almost any ear disorder. Common causes include acoustic trauma (noise-induced sensorineural hearing loss), sensorineural hearing loss from other causes, obstruction of the ear canal by cerumen or a foreign body, infections (external otitis, myringitis, otitis media, labyrinthitis, petrositis, syphilis, meningitis), and eustachian tube obstruction. Salicylates in high dosages may cause reversible tinnitus. Aminoglycoside antibiotics and some chemotherapeutic drugs (eg, cisplatin ) can cause hearing loss that may be accompanied by tinnitus.
Objective tinnitus, an uncommon occurrence involving an audible, pulsatile hum, can be caused by turbulent flow through the carotid artery or jugular vein. Highly vascular middle ear tumors (eg, glomus tympanicum and glomus jugulare tumors) and dural arteriovenous malformations (AVMs) may also cause objective tinnitus.
Evaluation
History:
Exposure to loud noise or to certain drugs before onset suggests acoustic trauma or ototoxicity, respectively. Unilateral tinnitus, particularly with hearing loss, may suggest acoustic neuroma. Acute unilateral hearing loss and vertigo, particularly after barotrauma, may suggest a perilymphatic fistula. Episodic tinnitus, fullness in the ear, severe vertigo, and fluctuating or permanent hearing loss in the same ear suggest Meniere's disease (see Inner Ear Disorders: Meniere's Disease).
Physical
examination:
Bruit or venous hum on auscultation of the neck suggests a vascular etiology. Bruit only on auscultation of the ear with use of an olive-tipped or electronic stethoscope suggests a dural AVM.
Testing:
An audiogram is performed, and if hearing loss is found, tests are done to differentiate conductive, sensory, and neural hearing losses (see Hearing Loss: Audiologic tests). Gadolinium-enhanced MRI rules out acoustic neuroma in cases of unilateral tinnitus, particularly in the presence of hearing loss. Other testing depends on patient presentation. Unilateral pulsatile and objective tinnitus may require investigation of the carotid and vertebral system with an arteriogram. In such cases, the risk of arteriogram must be weighed against the potential benefit of detecting and treating (with embolization) a potential dural AVM. Magnetic resonance angiography probably is not sensitive enough to detect most dural AVMs.
Treatment
Treatment of the underlying disease may lessen tinnitus. Correcting hearing loss (eg, with a hearing aid) relieves tinnitus in about 50% of patients. In some cases, recognizing and treating depression relieves tinnitus, suggesting a psychologic component. However, a psychologic cause should not be assumed.
Although no specific medical or surgical therapy is available, many patients find that background sound masks the tinnitus and may help them fall asleep. Some patients benefit from a tinnitus masker, a device worn like a hearing aid that provides a low-level sound that can suppress tinnitus. Electrical stimulation of the inner ear, as with a cochlear implant, occasionally reduces the tinnitus but is appropriate only for patients who are profoundly deaf.
Last full review/revision November 2005
Content last modified November 2005
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