Tinnitus: Essential Tests and Treatment Options - Otolaryngology

Dr. Ye Dawei reply Otolaryngology

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Mr.
The issue of tinnitus should first involve a hearing test, followed by an audiogram, to determine whether further examinations are necessary.
Here is an article for your reference.
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"Local Surrounding Central" – Correct Concepts in Treating Tinnitus
Mr.
Chang Chun-Hong of the Democratic Progressive Party wrote a small book years ago titled "The Road to Governance – The Theory and Practice of 'Local Surrounding Central'." In it, he discusses how the opposition party, the DPP, could seize local governance through elections of county and city mayors, and then push towards central governance and even presidential elections.
This strategy of surrounding the center with local power can also be applied to the diagnosis and treatment of the bothersome condition known as tinnitus.
Tinnitus is a highly subjective experience.
After a basic local examination by an otolaryngologist, which rules out earwax or otitis media, the doctor often arranges for a hearing test.
If there is hearing loss due to nerve damage, the doctor can only prescribe oral medications to prevent further deterioration of hearing, but there are no specific remedies for tinnitus.
If the audiogram shows normal hearing, it is often attributed to purely psychological factors.
The concept of "local surrounding central" suggests that tinnitus is rarely a singular event; patients often have other underlying conditions, and tinnitus may simply be one of the clinical manifestations of these diseases.
If treatment can be approached from the perspective of other clinical symptoms, and if these objective symptoms (like "local") improve while the subjective tinnitus (like "central") disappears, we can consider the treatment successful.
With the prosperity of society and economy, there has been a corresponding increase in patients with hypertension and hyperlipidemia.
Changes in entertainment among younger generations, such as KTV, concerts, and portable music players, are major causes of noise-induced tinnitus.
Additionally, the fierce competition in industrial society leads to vascular spasms in the cochlea, and the aging population has resulted in more cases of age-related vascular tinnitus.
These are all factors that an otolaryngologist must consider when treating tinnitus.
Below is an introduction to diseases related to tinnitus.
Classification of Tinnitus
"Tinnitus is a gradual onset of deafness," and "if tinnitus persists, it may lead to deafness." These ancient phrases highlight the potential severity of tinnitus.
The English term for tinnitus comes from the Latin word meaning "ringing." Scholars commonly classify tinnitus based on its causes as follows:
1.
Inner Ear Tinnitus: As the name suggests, this type of tinnitus arises from inner ear disorders.
The most well-known conditions include Meniere's disease and the increasingly common sudden sensorineural hearing loss.
I have previously discussed Meniere's disease in "A Discussion on Dizziness," and I will reiterate it here.
- Meniere's Disease: When the general public thinks of dizziness, they often think of "Meniere's," and even general practitioners frequently diagnose it as such.
However, there are not as many cases of Meniere's disease as one might think; many patients complain of dizziness and are overdiagnosed by physicians.
If the number of Meniere's cases is disproportionately high among patients in a neurotology clinic, the physician's competence may be questioned.
In simple terms, if a patient experiences dizziness, tinnitus, and hearing loss, the physician will consider this disease.
The renowned Japanese physician, Ichiro Kitabatake, even described it as a "7 points disease" due to the following characteristics:
1.
Severe dizziness: The sensation is akin to the world spinning and can last for several hours, with the first episode being the most intense.
2.
Spontaneous dizziness: It occurs without any apparent trigger and can happen suddenly.
3.
Recurrent dizziness: Patients with Meniere's disease often experience repeated episodes, rarely having just one.
4.
Reversible dizziness: There are periods of complete normalcy between episodes; dizziness does not last for days.
5.
Dizziness accompanied by cochlear nerve symptoms: Patients often experience fluctuating hearing, severe tinnitus during acute episodes, and sometimes perceive sounds at different frequencies.
6.
Hearing loss is often more pronounced at low frequencies.
7.
There is a "reverberation phenomenon," where patients often complain of discomfort in noisy environments like markets or stations.
To date, no laboratory test can definitively diagnose Meniere's disease, making a detailed medical history and basic physical examination crucial.
Patients often experience unforgettable episodes of severe dizziness accompanied by tinnitus, a sensation of ear fullness, and hearing loss.
These episodes do not occur daily, and their duration is not as brief as that of benign paroxysmal positional vertigo, nor as prolonged as vestibular neuritis.
Most patients experience dizziness for about 3 to 4 hours before gradually improving, but episodes may recur weeks later.
Many elderly patients report having recurrent dizziness since their youth, eventually leading to gradual hearing loss and persistent tinnitus.
This condition typically occurs between the ages of 20 and 40 and has a maternal inheritance pattern.
The cause is believed to be endolymphatic hydrops in the inner ear, leading to a sensation of ear fullness.
Treatment primarily involves medical management, including neuroprotective agents, vasodilators, and mild sedatives.
If episodes occur monthly, treatment should last at least four months; if they occur every two months, treatment should last at least five months, which is the interval between episodes plus three months.
If medication is ineffective or the patient cannot tolerate long-term medication, endolymphatic sac decompression surgery may be considered.
2.
Sudden Sensorineural Hearing Loss: "Sudden" means that the patient can clearly identify a specific day or moment when they suddenly lost hearing or experienced significant ringing.
This is considered an otolaryngological emergency, and patients are generally advised to seek immediate hospitalization.
Some patients may also experience dizziness and vomiting, necessitating a differential diagnosis from Meniere's disease.
Typically, dizziness occurs only once and lasts for a day or several days before subsiding, but hearing loss and tinnitus persist.
In contrast, Meniere's disease involves recurrent dizziness, but hearing often recovers more quickly after episodes.
A small number of acoustic neuroma cases may also present with sudden hearing loss, requiring a CT scan for differential diagnosis.
Commonly accepted causes include inner ear circulatory disturbances, viral infections, and autoimmune diseases.
Treatment has shifted from a "shotgun" approach to targeting the specific underlying cause for each case:
1.
Inner Ear Circulatory Disturbance: This occurs due to obstruction or spasm of the blood vessels supplying the inner ear, leading to hypoxia and hearing impairment.
It is more common in patients with systemic vascular diseases such as diabetes, hypertension, or hyperlipidemia.
Treatment primarily involves plasma expanders (e.g., Dextran), which is a glucose polymer that reduces blood viscosity and prevents thrombosis.
2.
Viral Infections: Many viruses can infect the inner ear, such as the rubella virus and cytomegalovirus, which can cause congenital deafness; mumps virus, measles virus, herpes zoster virus, and recently circulating influenza viruses can lead to acquired deafness.
Treatment typically involves corticosteroids, starting with 60 mg daily for six days, followed by a tapering regimen over two weeks.
3.
Autoimmune Diseases: Patients often have systemic autoimmune diseases such as lupus or rheumatoid arthritis, and bilateral hearing loss is common.
Initial assessments through medical history, physical examination, and electronystagmography (ENG) can help differentiate between central and peripheral causes.
Patients are generally advised to be hospitalized for at least a week; if hearing does not improve, they may be discharged, but if there is improvement, they may remain hospitalized for another week.
During hospitalization, daily hearing tests and eye movement changes are recorded, and follow-up appointments are scheduled every two weeks for three months post-discharge.
Prognostic indicators include: 1) earlier treatment leads to better outcomes; 2) high-frequency loss correlates with poorer prognosis; 3) patients with dizziness have a worse prognosis, while those with tinnitus retain cochlear nerve function, indicating a better prognosis; 4) older age correlates with poorer prognosis.
3.
Noise-Induced Tinnitus: Generally, noise-induced tinnitus can be divided into chronic noise exposure and acute trauma-induced tinnitus.
The former typically results from long-term exposure to noisy environments, while the latter can occur from sudden loud noises, such as explosions, gunfire, fireworks, or even popular rock concerts and portable music players among today's youth.
- Chronic Noise-Induced Hearing Loss: The modern industrialized society has brought prosperity but also a noisy environment.
Many work environments can lead to occupational injuries, such as railways, factories, airports, auto repair shops, DJs, video game store employees, and stockbrokers.
Noise levels below 80 decibels are less likely to cause hearing damage, but exposure to noise levels above 100 decibels for more than 8 hours can lead to temporary threshold shifts.
If individuals avoid loud noise promptly, hearing may recover.
However, if permanent threshold shifts occur, hearing loss becomes irreversible.
Pathologically, outer hair cells may degenerate, and stereocilia may fuse or disappear, resulting in irreversible tissue damage.
Labor safety regulations have established permissible noise exposure limits to protect workers' hearing, which can serve as a reference for daily life and work.
In principle, the maximum allowable industrial noise level is 90 decibels, and exposure should not exceed 8 hours per day.
- Acute Trauma-Induced Hearing Loss: This refers to inner ear damage caused by intense external sound stimuli over a short period.
Young people often frequent rock concerts, karaoke, and pubs, experiencing tinnitus, hearing loss, and a sensation of ear fullness the next day, which can be termed "disco deafness," "karaoke deafness," or "portable music player deafness." Following the presidential election, several patients presented with ear fullness, ear pain, and tinnitus after exposure to loudspeakers at campaign headquarters, which could be termed "election deafness." Additionally, the high-pressure shock waves from events like the explosion on Wall Street last year typically last more than 1.5 milliseconds, while gunfire shock waves last less than 1.5 milliseconds.
Unlike irreversible hearing loss from long-term noise exposure, these acute cases are due to transient auditory trauma, and prompt medical treatment is highly effective.
However, exposure to noise levels exceeding 130 decibels for prolonged periods (such as continuous firecrackers during weddings or funerals) can lead to decreased auditory tolerance, similar to the irreversible damage caused by chronic noise exposure.
4.
Metabolic Tinnitus: Among the metabolic causes of tinnitus, hyperlipidemia is the most common in the population.
Due to the economic prosperity of modern society, there is a widespread phenomenon of nutritional excess, leading to a significant increase in hyperlipidemia cases.
In neurotology clinics, up to 10% of patients may suffer from this condition.
These patients often complain of persistent "dizziness, brain fog, and tinnitus," experiencing an indescribable discomfort.
The mechanisms leading to tinnitus include: 1) The blood vessels in the inner ear are very delicate and lack collateral circulation, making it easy for lipids to deposit in the cochlea.
2) Increased blood viscosity can lead to poor circulation and embolism in the inner ear blood vessels.
Patients with hyperlipidemia seen in internal medicine often have other conditions such as hypertension, diabetes, atherosclerosis, or heart disease, requiring several months of medication before seeing results.
In contrast, patients with hyperlipidemia seen in neurotology clinics often present with tinnitus and dizziness as their initial symptoms, without accompanying systemic diseases.
Typically, they feel significantly better after just one week of medication.
Among all symptoms, dizziness responds best to treatment, followed by tinnitus, while hearing loss shows no improvement.
If patients stop medication after their lipid levels normalize but do not maintain a proper diet, they are likely to relapse.
However, once they resume medication, they immediately feel relieved.
Subsequent blood tests show lipid levels returning to normal, supporting our hypothesis.
5.
Vascular Tinnitus: The vertebral arteries supply blood to the brain and inner ear through the transverse foramina of the cervical vertebrae.
If the arteries supplying the inner ear become obstructed or spasmodic, it can lead to ischemia in the inner ear, causing abnormal discharges in the auditory nerve, which clinically presents as tinnitus.
Patients often experience dizziness, nausea, vomiting, and hearing loss, and may also have systemic symptoms such as occipital headaches, neck and shoulder pain, and numbness in the limbs.
This condition is more common in the elderly, who often have comorbidities such as hypertension, diabetes, heart disease, and hyperlipidemia.
For vascular tinnitus, which arises from poor blood circulation, traditional treatment often involves vasodilators to expand blood vessels for therapeutic effect.
However, in cases of atherosclerosis causing vessel narrowing, vasodilators lead to systemic dilation and do not selectively target the inner ear vessels.
Current approaches focus on improving hemodynamics, increasing the deformability of red blood cells, and reducing blood viscosity to ensure that the inner ear receives adequate oxygen and nutrients.
"Vasodilatory agents," which are designed based on this concept, can be derived from natural ginkgo biloba or synthesized.
Red blood cells are approximately 7 micrometers in diameter, while the true diameter of capillaries is only 3 to 4 micrometers.
These medications enhance the deformability of red blood cells, allowing them to pass through narrowed vessels more easily; they can also act on blood vessels to reduce spasms and prevent platelet aggregation, thereby promoting smooth blood flow.
6.
Tumor-Related Tinnitus: In otolaryngology, unilateral tinnitus should raise suspicion for two potential tumor diseases: nasopharyngeal carcinoma and acoustic neuroma.
This condition has also been mentioned in "A Discussion on Dizziness," and I will post it again.
- Acoustic Neuroma: The auditory nerve runs from the inner ear to the brainstem, with tumors most commonly appearing at the opening of the internal auditory canal, known as the cerebellopontine angle (CPA).
Initially, patients may only experience gradual unilateral hearing loss or tinnitus.
This tumor grows very slowly, so even if it compresses the vestibular nerve, central compensation may prevent dizziness.
As the tumor enlarges and compresses blood vessels, it can lead to sudden hearing loss or dizziness, and symptoms become increasingly diverse as the disease progresses.
If an acoustic neuroma is confined to the internal auditory canal and is less than 1 cm, it may be difficult to detect on a CT scan.
Some have attempted lumbar punctures to introduce air into the ventricles, positioning the patient to allow air to enter the internal auditory canal; if an acoustic neuroma is present, the air will not fill the canal, a technique known as "air CT." However, this method has the drawback of causing persistent headaches for about a week due to air in the cranial cavity.
With the advent of MRI, even tumors smaller than 1 cm can be easily diagnosed.
If the tumor grows larger and extends toward the cerebellum or brainstem, it may pose a life-threatening risk.
Clinically, patients may present with normal hearing and no dizziness, but auditory brainstem responses may show no reaction, necessitating consideration of this condition.
Prevention is Better than Treatment
Through the classification of tinnitus outlined above, we learn that many causes of tinnitus can be prevented in advance.
Patients with Meniere's disease should pay attention to their diet and avoid excessive salt intake.
The increase in cases of sudden sensorineural hearing loss may be related to the development of civilization and lifestyle stress.
Occupational noise injuries are often untreatable, so monitoring noise levels in the work environment is crucial.
Acute trauma-induced hearing loss responds well to early treatment, but it is even more important to avoid potentially harmful environments.
For metabolic tinnitus, in addition to managing underlying medical conditions, appropriate exercise and avoiding fatty foods can help maintain normal cholesterol levels.
Self-Assessment for Tinnitus
Through some carefully designed questions, we can often determine the potential causes of a patient's tinnitus.
Here are some simple questions:
1.
Is the tinnitus accompanied by dizziness? Does it become louder during dizziness? Tinnitus associated with dizziness suggests the possibility of "inner ear tinnitus." Meniere's disease, sudden sensorineural hearing loss, and anterior inferior cerebellar artery obstruction are often unilateral; vertebrobasilar insufficiency tends to be bilateral.
In Meniere's disease, tinnitus often becomes louder during dizziness.
2.
Is the work environment noisy? Have you worked in a high-noise environment for a long time? Have you been exposed to gunfire or fireworks? As mentioned earlier, human tolerance to noise is 90 decibels, and exposure should not exceed 8 hours per day.
If tinnitus occurs, it is essential to leave the noisy environment to prevent irreversible damage to cochlear hair cells.
Standard ear protection typically only reduces noise by 30 to 40 decibels and is ineffective against high-decibel noise from sources like airplane engines, trains, or lathes.
3.
Have you had blood tests for cholesterol levels? Do you have anemia, hypertension, thyroid disease, diabetes, or atherosclerosis? Tinnitus caused by systemic vascular diseases is often bilateral, so it is essential to rule out these conditions in tinnitus patients.
4.
Are you taking any long-term medications? Have you received antibiotic injections? Some medications, such as aspirin, quinine, contraceptives, antihypertensives, and antipsychotics, can sometimes cause bilateral tinnitus, which resolves upon discontinuation.
Older physicians sometimes administered streptomycin, kanamycin, or gentamicin, which can also lead to tinnitus with prolonged use.
Therefore, if tinnitus occurs after an injection, it is advisable to stop the injection to prevent irreversible damage.
5.
Is the tinnitus high-pitched or low-pitched? Is it unilateral or bilateral? Auditory nerve disorders typically present with high-pitched tinnitus, while Meniere's disease or middle ear disorders often present with low-pitched tinnitus.
Inner ear tinnitus is usually unilateral, while central vascular tinnitus is often bilateral.
6.
Is the tinnitus synchronized with your heartbeat? If tinnitus coincides with the heartbeat or pulse, it may indicate a vascular malformation or venous anomaly.
If turning the neck toward the affected side alleviates the tinnitus, it may suggest excessive pulsation in the neck vessels.
7.
Is the tinnitus related to breathing? Common respiratory infections or Eustachian tube obstruction during air travel can cause tinnitus.
Overactive Eustachian tubes can also lead to tinnitus, often accompanied by a sensation of ear vibration during breathing.
If bending down to tie shoelaces causes a sudden relief of symptoms due to increased blood flow to the brain, this may also be indicative.

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Reply Date: 2005/05/08