Tinnitus is when people think they hear something in their ears but there is actually no sound. People with tinnitus actually do "hear" noises that range from a whistle to a crackling noise to a roar. It can happen only occasionally, can occur for a period of days then take a break before recurring again, or it can be constant. The sound can vary in pitch from quiet to unbearably loud, or it can stay the same.
Tinnitus is believed to be caused by inner ear cell damage. Cilia in your inner ear move in relation to the pressure of sound waves. This triggers these cells to release an electrical signal through a nerve from your ear (auditory nerve) to your brain. Your brain interprets these signals as sound. If the hairs inside your inner ear are bent or broken, they can "leak" random electrical impulses to your brain, causing tinnitus.
Ototoxic drugs can also cause subjective tinnitus, as they may cause hearing loss, or increase the damage done by exposure to loud noise. Those damages can occur even at doses that are not considered ototoxic. Over 260 medications have been reported to cause tinnitus as a side effect. In many cases, however, no underlying cause could be identified.
Other causes of tinnitus include middle ear infections, disorders that block the ear canal (such as an external ear infection [external otitis], excessive ear wax, or foreign bodies), problems with the eustachian tube (which connects the middle ear and the back of the nose) due to allergies or other causes of obstruction, otosclerosis (a disorder of excess bone growth in the middle ear), and temporomandibular disorders. An uncommon but serious cause is an acoustic neuroma, a noncancerous (benign) tumor of part of the nerve leading from the inner ear.
Most people develop tinnitus as a symptom of hearing loss. When you lose hearing, your brain undergoes changes in the way it processes sound frequencies. A hearing aid is a small electronic device that uses a microphone, amplifier, and speaker to increase the volume of external noises. This can mollify neuroplastic changes in the brain’s ability to process sound.
Generally, following the initial evaluation, individuals suspected of rhythmic tinnitus will undergo some form of specialized medical imaging. Individuals may undergo high resolution computed tomography (HRCT) or magnetic resonance angiography (MRA) to evaluate blood vessel abnormalities such as a vascular malformation that may be the cause of tinnitus. An HRCT scan can also be used to evaluate the temporal bone for sinus wall abnormalities and superior semicircular canal dehiscence. HRCT uses a narrow x-ray beam and advanced computer analysis to create highly detailed images of structures within the body such as blood vessels. An MRA is done with the same equipment use for magnetic resonance imaging (MRI). An MRI uses a magnetic field and radio waves to produce cross-sectional images of particular structures or tissues within the body. An MRA provides detailed information about blood vessels. In some cases, before the scan, an intravenous line is inserted into a vein to release a special dye (contrast). This contrast highlights the blood vessels, thereby enhancing the results of the scan.
Tinnitus can be triggered by a variety of different causes, and it varies dramatically from person to person. Some of the causes result in permanent tinnitus that may require treatment, while others result in temporary tinnitus that disappears on its own. Common causes of tinnitus include hearing loss, wax buildup, stress, exposure to loud noises, certain disorders, and certain medications. To learn more about the various causes of tinnitus, check out our page What Causes Tinnitus?
Cochlear Implants. These implants are a treatment option for patients that have a severe hearing loss along with tinnitus. Cochlear implants are designed to bypass any damaged parts of the inner ear and send the electrical signals sound makes directly to the auditory nerve. By bringing in outside noise, these implants can effectively mask your tinnitus, as well as stimulate your neural circuits to change.
Sound therapies are one method that has previously been shown to reduce the severity of tinnitus. While not all sound therapies have gone through rigorous clinical testing, they have far greater traction and adoption in the tinnitus community. There are two types of sound therapy approaches: (1) maskers that are intended to block out the tinnitus and have the patient learn to ignore their tinnitus, and (2) sound therapies that utilize the same brain plasticity that is thought to be causing the tinnitus for the purpose of reducing it. Both approaches can be delivered via electronic devices that can produce sound. There has been an increase in tinnitus maskers that are built into hearing aids. These built-in maskers generate different sounds including white noise and random tones. Unfortunately, due to their design, hearing aids are still limited to providing masking at frequencies below 8 kHz.
Steven Doerr, MD, is a U.S. board-certified Emergency Medicine Physician. Dr. Doerr received his undergraduate degree in Spanish from the University of Colorado at Boulder. He graduated with his Medical Degree from the University Of Colorado Health Sciences Center in Denver, Colorado in 1998 and completed his residency training in Emergency Medicine from Denver Health Medical Center in Denver, Colorado in 2002, where he also served as Chief Resident.
If your tinnitus is a symptom of an underlying medical condition, the first step is to treat that condition. But if the tinnitus remains after treatment, or if it results from exposure to loud noise, health professionals recommend various non-medical options that may help reduce or mask the unwanted noise (See Masking Devices below). Sometimes, tinnitus goes away spontaneously, without any intervention at all. It should be understood, however, that not all tinnitus can be eliminated or reduced, no matter the cause.
The use of sound therapy by either hearing aids or tinnitus maskers helps the brain ignore the specific tinnitus frequency. Although these methods are poorly supported by evidence, there are no negative effects. There is some tentative evidence supporting tinnitus retraining therapy. There is little evidence supporting the use of transcranial magnetic stimulation. It is thus not recommended. As of 2017 there was limited evidence as to whether neurofeedback is or is not helpful.
Tinnitus usually comes in the form of a high-pitched tone in one or both ears, but can also sound like a clicking, roaring or whooshing sound. While tinnitus isn't fully understood, it is known to be a sign that something is wrong in the auditory system: the ear, the auditory nerve that connects the inner ear to the brain, or the parts of the brain that process sound. Something as simple as a piece of earwax blocking the ear canal can cause tinnitus, but it can also arise from a number of health conditions. For example, when sensory cells in the inner ear are damaged from loud noise, the resulting hearing loss changes some of the signals in the brain to cause tinnitus.
To keep the brain activated and aware, Kilgard’s therapy involves stimulating the vagus nerve, which is actually a pair of nerves that runs inside the neck and into the brain. “All the stuff you brains learns about your body — it all comes in through the vagus nerve,” he says. “We trick the brain into thinking it’s learning something important by stimulating this nerve in the neck.”
Pulsatile tinnitus: This problem usually is related to blood flow, either through normal or abnormal blood vessels near the ear. Causes of pulsatile tinnitus include pregnancy, anemia (lack of blood cells), overactive thyroid, or tumors involving blood vessels near the ear. Pulsatile tinnitus also can be caused by a condition known as benign intracranial hypertension (an increase in the pressure of the fluid surrounding the brain).
It is possible that the most common cause of pulsatile tinnitus is sigmoid sinus diverticulum and dehiscence, which can be collectively referred to as sinus wall abnormalities or SSWA. The sigmoid sinus is a blood carrying channel on the side of the brain that receives blood from veins within the brain. The blood eventually exits through the internal jugular vein. Sigmoid sinus diverticulum refers to the formation of small sac-like pouches (diverticula) that protrude through the wall of the sigmoid sinus into the mastoid bone behind the ear. Dehiscence refers to absence of part of the bone that surrounds the sigmoid sinus in the mastoid. It is unknown whether these conditions represent different parts of one disease process or spectrum, or whether they are two distinct conditions. These abnormalities cause pressure, blood flow, and noise changes within the sigmoid sinus, which ultimately results in pulsatile tinnitus. Narrowing of the blood vessel that leads into the sigmoid sinus, known as the transverse sinus, has also been associated with pulsatile tinnitus.
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