Tinnitus
Tinnitus is the hearing of sound when no external sound is present.
It is often described as a ringing in the ear, but may also sound like a clicking, hiss or roaring. Rarely, unclear voices or music are heard.
The sound may be soft or loud, low pitched or high pitched and appear to be coming from one ear or both. Most of the time, it comes on gradually.
In some people, the sound causes depression, anxiety or interferes with concentration.
Tinnitus is common, affecting about 10-15% of people.
Most, tolerate it well. It is only a significant problem in only 1-2% of people.
The below article unpacks the causes, symptoms, prevention and treatment of Tinnitus.
What Are You Looking For?
1. Signs, Symptoms and Psychological effects
2. Causes of Tinnitus
3. Types of Tinnitus
4. Pathophysiology
5. Diagnosis
6. Prevention and Treatment
7. Tinnitus in Children
1. Signs, Symptoms and Psychological effects
Tinnitus is the hearing of sound when no external sound is present.
Tinnitus is described as a noise inside a person’s head in the absence of auditory stimulation.
Tinnitus can be perceived in one or both ears or in the head.
The noise is described in many different ways – but the most common description of the tinnitus is a pure tone sound. It is usually described as a ringing noise but, in some patients, it takes the form of a high-pitched whining, electric buzzing, hissing, humming, tinging or whistling sound or as ticking, clicking, roaring, “crickets” or “tree frogs” or “locusts (cicadas)”, tunes, songs, beeping, sizzling, sounds that slightly resemble human voices or even a pure steady tone like that heard during a hearing test and, in some cases, pressure changes from the interior ear.
It has also been described as a “whooshing” sound because of acute muscle spasms, as of wind or waves.
Tinnitus can be intermittent or it can be continuous: in the latter case, it can be the cause of great distress.
In some individuals, the intensity can be changed by shoulder, head, tongue, jaw or eye movements.
Most people with tinnitus have some degree of hearing loss. They are often unable to clearly hear external sounds that occur within the same range of frequencies as their “phantom sounds”. This has led to the suggestion that one cause of tinnitus might be a homeostatic response of central dorsal cochlear nucleus auditory neurons that makes them hyperactive in compensation to auditory input loss.
The sound perceived may range from a quiet background noise to one that can be heard even over loud external sounds. The specific type of tinnitus called pulsatile tinnitus is characterized by hearing the sounds of one’s own pulse or muscle contractions, which is typically a result of sounds that have been created from the movement of muscles near to one’s ear, changes within the canal of one’s ear or issues related to blood flow of the neck or face.
2. Causes of Tinnitus
Tinnitus is not a disease but a symptom that can result from a number of underlying causes. It is more common in those with depression. As of 2013, there are no effective medications. One of the most common causes is noise-induced hearing loss.
Other causes include:
3. Types of Tinnitus
There are two types of tinnitus: Subjective tinnitus and Objective tinnitus.
Subjective tinnitus, also called tinnitus aurium, non-auditory and non-vibratory tinnitus – meaning others cannot hear it.
Occasionally, tinnitus may be heard by someone else using a stethoscope, in which case, it is objective tinnitus.
Objective tinnitus has been called pseudo-tinnitus or vibratory tinnitus.
Subjective Tinnitus
Subjective tinnitus is the most common type of tinnitus. It can have many possible causes, but the most frequent cause of subjective tinnitus is noise exposure which damages hair cells in the inner ear causing tinnitus. Subjective tinnitus can only be heard by the affected person and is caused by otology, neurology, infection or drugs.
There is a growing body of evidence suggesting that tinnitus is a consequence of neuroplastic alterations in the central auditory pathway. These alterations are believed to be the result of a disturbed sensory input, caused by hearing loss. Hearing loss could indeed cause a homeostatic response of neurons in the central auditory system, and therefore cause tinnitus. Despite the opinion amongst researchers that tinnitus is primarily a central nervous system pathology, there certainly exists a class of people whose tinnitus is peripherally based.
Objective Tinnitus
Objective tinnitus can be detected by other people and is usually caused by myoclonus or a vascular condition. In some cases, tinnitus is generated by a self-sustained oscillation within the ear. This is called objective tinnitus which can arise from muscle spasms around the middle ear.
Homeostatic control mechanisms exist to correct the problem within a minute after onset and is normally accompanied by a slight reduction in hearing sensitivity followed by a feeling of fullness in the ear.
Objective tinnitus can most often can be heard as a sound outside the ear, as spontaneous otoacoustic emissions (SOAEs) that can form beats with and lock into external tones. The majority of the people are unaware of their SOAEs; whereas portions of 1-9% perceive a SOAE as an annoying tinnitus.
Pulsatile Tinnitus
Pulsatile tinnitus can be a symptom of intracranial vascular abnormalities and should be evaluated for bruits. Some people experience a sound that beats in time with their pulse (pulsatile tinnitus, or vascular tinnitus). Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow, increased blood turbulence near the ear (such as from atherosclerosis, venous hum, but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear.
Rarely, pulsatile tinnitus may be a symptom of potentially life-threatening conditions such as carotid artery aneurysm or carotid artery dissection. Pulsatile tinnitus may also indicate vasculitis, or more specifically, giant cell arteritis. Pulsatile tinnitus may also be an indication of idiopathic intracranial hypertension.
Hearing loss
The most common cause of tinnitus is noise-induced hearing loss. Hearing loss may be implicated even for people with normal audiograms.
Hearing loss may have many different causes; but among tinnitus subjects, the major cause is cochlear damage.
Ototoxic drugs (such as aspirin) 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. Tinnitus is also a classical side effect of quinidine, a Class IA anti-arrhythmic. Over 260 medications have been reported to cause tinnitus as a side effect. In many cases, however, no underlying cause can be identified.
Tinnitus can also occur due to the discontinuation of therapeutic doses of benzodiazepines. It can sometimes be a protracted symptom of benzodiazepine withdrawal and may persist for many months.
4. Pathophysiology
One of the possible mechanisms relies on otoacoustic emissions.
The inner ear contains tens of thousands of minute inner hair cells with stereocilia which vibrate in response to sound waves and outer hair cells which convert neural signals into tension on the vibrating basement membrane.
The sensing cells are connected with the vibratory cells through a neural feedback loop, whose gain is regulated by the brain.
This loop is normally adjusted just below onset of self-oscillation, which gives the ear spectacular sensitivity and selectivity. If something changes, it is easy for the delicate adjustment to cross the barrier of oscillation and, then, tinnitus results. Exposure to excessive sound kills hair cells and studies have shown that, as hair cells are lost, different neurons are activated, activating auditory parts of the brain and giving the perception of sound.
Another possible mechanism underlying tinnitus is damage to the receptor cells. Although receptor cells can be regenerated from the adjacent supporting Deiters cells after injury in birds, reptiles and amphibians, it is believed that, in mammals, they can be produced only during embryogenesis.
Although mammalian Deiters cells reproduce and position themselves appropriately for regeneration, they have not been observed to transdifferentiate into receptor cells except in tissue culture experiments.
If these hairs become damaged, through prolonged exposure to excessive sound levels, for instance, then deafness to certain frequencies results. In tinnitus, they may relay information that an externally audible sound is present at a certain frequency when it is not.
5. Diagnosis
The diagnosis of tinnitus is usually based on the person’s description, A number of questionnaires exist that assess how much tinnitus is interfering with a person’s life. The diagnosis is commonly assisted with an audiogram and neurological exam. If certain problems are found, medical imaging, such as with MRI, may be performed.
Other tests are suitable when tinnitus occurs with the same rhythm as the heartbeat. Occasionally, the sound may be heard by someone else using a stethoscope, in which case it is known as objective tinnitus.
Prevention involves avoiding loud noise. If there is an underlying cause, treating it may lead to improvements. Otherwise, typically, management involves talk therapy. Sound generators or hearing aids may help.
Even when tinnitus is the primary complaint, audiological evaluation is usually preceded by examination by an ENT to diagnose treatable conditions like middle ear infection, acoustic neuroma, concussion, otosclerosis, etc.
The accepted definition of chronic tinnitus, as compared to normal ear noise experience, is five minutes of ear noise occurring at least twice a week. However, people with chronic tinnitus often experience the noise more frequently than this and can experience it continuously or regularly, such as during the night when there is less environmental noise to mask the sound.
Severity
The condition is often rated on a scale from “slight” to “catastrophic” according to the effects it has, such as interference with sleep, quiet activities and normal daily activities. In an extreme case a man committed suicide after being told there was no cure
Assessment of psychological processes related to tinnitus involves measurement of tinnitus severity and distress (i.e. nature and extent of tinnitus-related problems), measured subjectively by validated self-report tinnitus questionnaires.
These questionnaires measure the degree of psychological distress and handicap associated with tinnitus, including effects on hearing, lifestyle, health and emotional functioning. A broader assessment of general functioning, such as levels of anxiety, depression, stress, life stressors and sleep difficulties, is also important in the assessment of tinnitus due to higher risk of negative well-being across these areas, which may be affected by and/or exacerbate the tinnitus symptoms for the individual.
Overall, current assessment measures are aimed to identify individual levels of distress and interference, coping responses and perceptions of tinnitus in order to inform treatment and monitor progress. However, wide variability, inconsistencies and lack of consensus regarding assessment methodology are evidenced in the literature, limiting comparison of treatment effectiveness. Developed to guide diagnosis or classify severity, most tinnitus questionnaires have also been shown to be treatment-sensitive outcome measures.
6. Prevention and Treatment
Prolonged exposure to loud sound or noise levels can lead to tinnitus. Ear plugs or other measures can help with prevention.
Several medicines have ototoxic effects, and can have a cumulative effect that can increase the damage done by noise. If ototoxic medications must be administered, close attention by the physician to prescription details, such as dose and dosage interval, can reduce the damage done.
Management
If there is an underlying cause, treating it may lead to improvements. Otherwise, the primary treatment for tinnitus is talk therapy and sound therapy; there are no effective medications.
Psychological
The best supported treatment for tinnitus is a type of counseling called cognitive behavioral therapy (CBT) which can be delivered via the internet or in person. It decreases the amount of stress those with tinnitus feel. These benefits appear to be independent of any effect on depression or anxiety in an individual. Acceptance and commitment therapy (ACT) also shows promise in the treatment of tinnitus. Relaxation techniques may also be useful.
Medications
Currently, there is no approved medication solely for the treatment of tinnitus. While there is no known cure, many people adapt over time, and for a majority the condition becomes manageable. However, for a subset of patients tinnitus remains a significant and persistent problem.”
7. Tinnitus in Children
Tinnitus is commonly thought of as a symptom of adulthood, and is often overlooked in children. Children with hearing loss have a high incidence of tinnitus, even though they do not express the condition or its effect on their lives.
Children do not generally report tinnitus spontaneously and their complaints may not be taken seriously.
Among those children who do complain of tinnitus, there is an increased likelihood of associated otological or neurological pathology such as migraine, juvenile Meniere’s disease or chronic suppurative otitis media.
Its reported prevalence varies from 12% to 36% in children with normal hearing thresholds and up to 66% in children with a hearing loss and approximately 3–10% of children have been reported to be troubled by tinnitus.