Additional evaluations. Results of patient examinations and history collection might warrant additional evaluations. For example, asymmetrical hearing loss (15 dB or greater asymmetry at 2 or more consecutive test frequencies) and unilateral tinnitus can indicate a retrocochlear lesion such as acoustic neuroma (also known as vestibular schwannoma).
One test for retrocochlear pathology is the auditory brainstem response (ABR). In this test, clicks are presented through earphones while scalp electrodes record brain responses to the sounds. Abnormal ABR waveforms can indicate retrocochlear lesion (such as acoustic neuroma) as a possible cause of ipsilateral hearing loss and tinnitus. If positive ABR results are obtained, MRI evaluation of the cerebellopontine angle with contrast material (such as gadolinium) should be performed.
Low-pitched roaring, ringing, or hissing tinnitus; hearing loss, which may be temporary or permanent; vertigo; and a feeling of pressure or fullness in the ear can indicate endolymphatic hydrops or Meniere’s disease. Symptoms usually occur in the form of “attacks” that increase in frequency during the first few years of the disease, then decrease in frequency as hearing thresholds stabilize. Electrocochleography testing is one way to diagnose endolymphatic hydrops. Patients who exhibit vestibular disorders should undergo electronystagmography testing to assess the severity and characteristics of their symptoms.
Pulsatile tinnitus associated with abnormalities of blood vessels in the neck can be evaluated with sonography, conventional angiography, or magnetic resonance angiography. Conditions such as a dehiscent jugular bulb or stenosis of carotid arteries can sometimes be treated surgically. However, many forms of pulsatile tinnitus are not caused by these conditions. Pulsatile tinnitus is often a consequence of hearing loss, arteriosclerosis, or weight loss or weight gain. These physiologic changes can cause patients to hear blood pulsing or “swishing” in vessels—sounds they did not perceive previously. Surgery is not recommended for most cases of pulsatile tinnitus.
Sudden hearing loss, especially if bilateral, might indicate autoimmune inner ear disease. Diagnostic tests include the Western blot immunoassay.
Treatment of active disease processes
Many contributors to tinnitus can be treated surgically or with medication.
Otitis media. Successful treatment of the infection with oral antibiotics usually resolves all auditory symptoms.
Allergies, sinus congestion, or infection. When inflammation subsides, tinnitus associated with these conditions usually resolves.
Otosclerosis. Abnormal accumulations of calcium on middle-ear ossicles (especially the stapes) or the cochlea can result in slowly progressing conductive or sensorineural hearing loss, tinnitus, and vestibular disturbances. Stapedectomy surgery—including implantation of ossicular prostheses—is often successful for advanced cases associated with significant hearing loss. Hearing aids also benefit some patients.
Meniere’s disease or other forms of endolymphatic hydrops. Meniere’s disease, characterized by abnormally high fluid pressure within the cochlea, has an estimated prevalence of 1% in the US.14 Management includes meclizine, antiemetics and diuretics, and a low-sodium diet.15 If patients do not respond to meclizine, diazepam can be prescribed to reduce the severity of vertigo attacks. Surgical intervention—including installation of an endolymphatic shunt, labyrinthectomy, or vestibular neurectomy16—or transtympanic injections of gentamicin17 are options in severe cases.
Autoimmune inner ear disease. This disease has an estimated prevalence of 0.1% in the US.18 Symptoms include sudden hearing loss in one ear that usually progresses to the second ear. Patients may also feel fullness in the ear and experience vertigo as well as ringing, hissing, or roaring tinnitus. Most patients with autoimmune inner ear disease respond to initial treatment with oral prednisone.
Auditory neoplasms. Growths such as acoustic neuroma or cholesteatoma can cause tinnitus. Acoustic neuroma (or vestibular schwannoma) is a benign neoplasm that arises from the vestibular division of the eighth cranial nerve. Symptoms include unilateral hearing loss, tinnitus, and vestibular disturbances. Surgical resection or radiation treatment of the tumor can resolve these symptoms, especially if the neoplasm is detected while it is small.
Cholesteatoma is a benign epithelial cell mass that grows in the middle-ear cavity. Over time, cholesteatomas can enlarge and destroy middleear ossicles. Hearing loss, tinnitus, dizziness, and facial muscle paralysis can result from continued cholesteatoma growth. Early detection and surgical resection of auditory neoplasms can reduce the likelihood of residual symptoms.
Hyper- or hypotension. Of these two disorders, hypertension is more likely to contribute to tinnitus. Maintenance of blood pressure within the optimum range can decrease or resolve tinnitus for some patients.
Metabolic disorders. Disorders such as diabetes mellitus, hyperthyroidism, or hypothyroidism can contribute to tinnitus. Successful management of these conditions can reduce or resolve the patient’s tinnitus.
Managing persistent tinnitus
Successful treatment of the disorders discussed can resolve or reduce tinnitus. However, if tinnitus continues to bother the patient after other diseases have been treated, shift the clinical focus from treatment to management of the symptom. At this point, the clinician should do 1 of 2 things: 1) spend the time necessary to help the patient manage tinnitus using strategies described in the following sections of this article; or 2) refer the patient to a comprehensive tinnitus management program with experienced personnel who are willing and able to spend a substantial amount of time with each patient.