Tinnitus is defined by Webster’s Dictionary as “a sensation of noise (as a ringing or roaring) that is caused by a bodily condition (as a disturbance of the auditory nerve or wax in the ear) and typically is of the subjective form which can only be heard by the one affected” (http://www.merriam-webster.com/dictionary/tinnitus). It has been reported that more than 50 million Americans have experienced tinnitus at some point in their lives, and today 1 in 5 people have symptoms of tinnitus that impact their lives in a negative way. Tinnitus can be either intermittent or constant and in one ear or both.
Symptoms, Causes, and Etiology
Patients experiencing tinnitus often present with varying types and severity of symptoms. Tinnitus is most commonly described as a “ringing” in the ears but can also be described variably as a buzzing sound, a whining sound, a tickling sensation, or a beeping sound among many others. The symptoms of tinnitus can be constant or intermittent with hours, days, or even weeks between events. It can affect one ear or both. In addition to the typical symptoms of tinnitus, many individuals suffer from varying degrees of hearing loss as well. Particularly frustrating to many patients is the fact that tinnitus is almost always something that only the patient can hear, which makes it a very subjective disease and one that is difficult to treat.
In many cases, the cause or etiology of tinnitus is not well known or understood. Studies have been done looking at various aspects of the auditory system as well as more systemic causes in the brain or causes that may be behavioral or psychological. Some cases of tinnitus are thought to be caused by the buildup of cerumen (earwax) within the outer ear or the external auditory canal. Often if this cerumen is in direct contact with the eardrum or tympanic membrane, it can cause the symptoms of tinnitus. Infections of the middle ear as well as a more rare condition known as otosclerosis (hardening of the middle ear bones or ossicles) have also been known to cause the symptoms of tinnitus. While middle ear infections are relatively easy to treat, otosclerosis is a condition with no known treatment. Finally, tinnitus is also thought to be caused by damage or loss of the hair cells within the inner ear that are connected directly to the auditory nerve. This damage has been shown to be caused by high volume/frequency noise, some medications, and most commonly aging.
There are a wide variety of other diseases that have tinnitus as a presenting symptom. Some of the more common include Meniere’s disease, Arnod-Chiari malformation, trauma/head injuries resulting in skull fractures or concussions, metabolic diseases such as thyroid dysfunction or hyperlipidemia, vitamin B12 deficiency, Lyme disease, and migraine headaches. Psychedelic drugs and benzodiazepine withdrawal have also been known to cause temporary symptoms of tinnitus.
Diagnosis and Treatment
Diagnosis of tinnitus is very difficult given the subjective nature of this disease. Often, physicians will begin treating the symptoms to determine if they are transient or not. If symptoms persist, diagnostic tests such as audiograms (hearing tests), CAT (computerized axial tomography) scans, or MRI (magnetic resonance imaging) scans can be done to determine if there are any physical abnormalities within the auditory system or the brain. CAT scans and MRIs are often done when a patient complains of pulsatile tinnitus or asymmetric hearing loss as both of these symptoms can be related to significant vascular issues or acoustic neuromas.
While treatment for tinnitus varies widely depending on the duration and severity of the symptoms, there are a number of common treatments used by medical professionals to try to decrease the frequency and intensity of symptoms. Some of these include the use of (1) hearing aids, which can help individuals who are also suffering from hearing loss, (2) wearable sound generators, which are small electronic devices that emit “white noise” to mask the louder tinnitus, or (3) antidepressant/antianxiety medications, which can sometimes help patients who are suffering from loss of sleep or anxiety brought on by the constant symptoms of tinnitus; and in extreme cases (4) the use of cochlear implants or acoustic neural stimulation, which can be used either to bypass the inner ear or to provide a broadband acoustic signal that offsets the tone of the tinnitus. While many of these treatments often help patients with tinnitus, to date, there is no known effective treatment to stop the symptoms of this disease completely.
Charles A. Ferguson
See also: Auditory Hallucinations; Auditory System; Auditory Threshold; Brainstem Auditory Evoked Potentials; Vestibulocochlear Nerve
Langguth, Berthold, Peter M. Kreuzer, Tobias Kleinjung, & Dirk De Ridder. (2013). Tinnitus: Causes and clinical management. Lancet Neurology, 12(9), 920—930.
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National Institute on Deafness and Other Communication Disorders (NIDCD). (2014). Tinnitus. Retrieved from http://www.nidcd.nih.gov/health/hearing/pages/tinnitus.aspx
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