Tinnitus: Insights from an ENT Specialist - Otolaryngology

Dr. Ye Dawei reply Otolaryngology

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Miss Huihui, most cases of pulsatile tinnitus are benign.
Only a very small number may be caused by arteriovenous malformations in the brain, which can be detected through a CT scan or MRI.
Attached is an article for your reference.

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"Local Encircles Central" – Correct Concepts for Treating Tinnitus
Mr.
Chang Junhong from the Democratic Progressive Party wrote a small book years ago titled "The Path to Governance – The Theory and Practice of 'Local Encircling Central'," in which he discussed how the opposition DPP could gain local governance power through elections of county and city mayors in Taiwan, and then push towards central government and even presidential elections.
This strategy of using local encirclement to create a governance atmosphere can also be applied to the diagnosis and treatment of the bothersome condition of tinnitus.
Tinnitus is a highly subjective experience; after a basic local examination by an ENT doctor, which rules out earwax or otitis media, the doctor often arranges for a hearing test.
If hearing loss is present and is of a neurological nature, the doctor can only prescribe oral medications to prevent further deterioration of hearing, but there are no specific remedies for tinnitus treatment.
If the hearing test shows normal results, it is often considered purely psychological.
The concept of "local encircling central" suggests that tinnitus is rarely a singular event; patients often have other underlying conditions accompanying their tinnitus, and it is likely that tinnitus is just one clinical manifestation of these diseases.
If treatment can be approached from the perspective of other clinical symptoms, and if these objective symptoms (like "local") improve, leading to the subjective tinnitus (like "central") disappearing, we can consider the treatment a success.
With the prosperity of socioeconomic development, there has been a corresponding increase in patients with hypertension and hyperlipidemia.
Changes in entertainment among younger populations, such as KTV, concerts, and personal music devices, are also major causes of noise-induced tinnitus.
Additionally, the intense competition in industrial society has led 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 ENT doctor must consider when treating tinnitus.
Below is an introduction to diseases related to tinnitus.
Classification of Tinnitus
"Tinnitus is a gradual loss of hearing," and "if tinnitus persists, it may lead to deafness." These ancient phrases highlight the potential for tinnitus to cause serious hearing loss.
The English term for tinnitus originates from the Latin word meaning "ringing." Scholars generally classify tinnitus based on its causes as follows:
1.
Inner Ear Tinnitus: As the name suggests, this type of tinnitus is caused by lesions in the inner ear.
The most notable conditions include Meniere's disease and the increasingly common sudden sensorineural hearing loss.
I have previously discussed this in "A Casual Talk 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 may diagnose it as such.
In reality, there are not as many cases of Meniere's disease as reported; 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 impairment, the doctor 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: It feels as if the world is spinning and can last for several hours, with the first episode being the most intense.
2.
Spontaneous dizziness: It occurs without any triggers and can happen suddenly.
3.
Recurrent dizziness: Patients with Meniere's disease often experience repeated episodes, rarely just one occurrence.
4.
Reversible dizziness: There are periods of complete normalcy between episodes, and dizziness does not last for several 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 impairment is often evident in low frequencies.
7.
There may be a "reverberation phenomenon," where patients complain of discomfort in noisy environments like markets or stations.
To date, there are no laboratory tests that can definitively diagnose Meniere's disease, making detailed medical history and basic physical examination very important.
Patients often experience unforgettable episodes of severe dizziness accompanied by tinnitus, a feeling of fullness in the ear, and hearing loss.
These episodes do not occur daily and last longer than the brief episodes seen in benign paroxysmal positional vertigo, nor do they last for several days like vestibular neuritis.
Most patients experience dizziness for about 3 to 4 hours, which gradually alleviates, but they may have another episode a few weeks later.
Many elderly patients report having recurrent dizziness since their youth, with gradually worsening hearing and persistent tinnitus.
This disease commonly 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 fullness in the ear.
Treatment primarily involves medical management, including neuroprotective agents, vasodilators, and mild sedatives.
If episodes occur once a month, 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 indicate a specific day or even a moment when they suddenly lost hearing or experienced severe ringing.
This is considered an ENT emergency, and patients are generally advised to seek immediate hospitalization.
Some patients may also experience dizziness and vomiting, necessitating differentiation from Meniere's disease.
Typically, it only causes dizziness once, lasting a day or several days without recurrence, but persistent hearing loss and tinnitus may continue.
Meniere's disease, on the other hand, tends to have recurrent dizziness but quicker recovery of hearing after episodes.
A small number of acoustic neuroma cases may also present with sudden hearing loss, requiring CT for differential diagnosis.
The causes are widely accepted to 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.
Therefore, treatment focuses on 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, varicella-zoster virus, and recently circulating influenza viruses can cause acquired deafness.
Treatment involves corticosteroids, starting with a dose of 60 mg per day for six days, then tapering over two weeks.
3.
Autoimmune Diseases: Patients often have systemic autoimmune diseases such as lupus or rheumatoid arthritis and may experience bilateral hearing impairment.
Diagnosis is based on medical history, physical examination, and electronystagmography (ENG) to 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; if there is improvement, they may stay for another week.
During hospitalization, daily hearing tests and monitoring of eye movement changes are conducted, with follow-up every two weeks after discharge for three months.
Prognostic indicators include: 1) earlier treatment leads to better outcomes; 2) high-frequency loss has a poorer prognosis; 3) patients with dizziness have a poorer prognosis, while those with tinnitus still have cochlear nerve function, indicating a better prognosis; 4) older age correlates with a poorer prognosis.
3.
Noise-Induced Tinnitus: Generally, noise-induced tinnitus can be divided into chronic noise exposure and acute trauma-induced tinnitus.
The former is often due to long-term exposure to noisy environments, while the latter can result from events like explosions, gunfire, fireworks, or loud concerts.

- Chronic Noise-Induced Hearing Loss: The modern industrialized society has brought prosperity but also a noisy environment.
Many workplaces can lead to occupational injuries, such as railways, factories, airports, auto repair shops, DJs, arcade workers, 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 eight hours can lead to temporary threshold shifts.
If one avoids loud noise promptly, hearing may recover.
However, if permanent threshold shifts occur, hearing loss is irreversible.
Pathologically, one may observe degeneration of outer hair cells and fusion or loss of stereocilia in the inner ear, which is an irreversible tissue injury.
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 permissible industrial noise level is 90 decibels, and exposure should not exceed eight hours per day.
- Acute Trauma-Induced Hearing Loss: This refers to inner ear damage caused by a sudden loud external sound.
Young people often frequent rock concerts, karaoke, and pubs, and may experience tinnitus, hearing loss, and a sensation of fullness in the ear the next day, which can be termed "disco deafness," "karaoke deafness," or "personal music device deafness." After the presidential election, several patients presented with symptoms of ear fullness, 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 longer than 1.5 milliseconds, while gunfire shock waves typically last less than 1.5 milliseconds.
Unlike irreversible hearing loss caused by long-term noise exposure, these acute cases are due to transient auditory trauma, and prompt treatment with medication is highly effective.
It is strongly recommended to seek immediate treatment to restore hearing.
However, if noise exposure exceeds 130 decibels for prolonged periods (such as continuous firecrackers during celebrations), it can lead to a decrease in the ear's adaptability to noise, resulting in irreversible damage similar to chronic noise-induced hearing loss.
4.
Metabolic Tinnitus: The most common cause of metabolic tinnitus in our population is hyperlipidemia, which has surged due to the economic prosperity of modern society, leading to widespread nutritional excess.
In neurotology clinics, up to 10% of patients may have this condition.
Patients with hyperlipidemia often complain of persistent "dizziness, brain fog, and tinnitus," experiencing a vague discomfort.
The mechanisms causing 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 in the inner ear.
Patients with hyperlipidemia seen in internal medicine often have other comorbidities such as hypertension, diabetes, atherosclerosis, or heart disease, requiring several months of medication before seeing effects.
In neurotology, hyperlipidemia patients often present with tinnitus and dizziness as their initial symptoms, without accompanying internal diseases, and typically 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 blood lipid levels normalize after stopping medication, patients are likely to relapse if they do not maintain a proper diet, but once they resume medication, they feel immediate relief.
Subsequent blood tests often show normalized lipid levels, supporting our hypothesis.
5.
Vascular Tinnitus: The vertebral arteries travel through the transverse foramen of the sixth cervical vertebra, ascending to the brain where they join the basilar artery, branching into the anterior inferior cerebellar artery, posterior inferior cerebellar artery, and superior cerebellar artery, supplying circulation to the brainstem, cerebellum, and inner ear.
If the arteries supplying the inner ear become obstructed or spasm, it can easily lead to ischemia in the inner ear, causing abnormal discharges in the auditory nerve, clinically presenting as tinnitus.
These patients often also experience dizziness, nausea, vomiting, and hearing loss, and may have systemic symptoms such as occipital headaches, neck and shoulder pain, and numbness in the limbs due to insufficient blood supply to the posterior cranial fossa.
Most patients are elderly and 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 in hopes of expanding blood vessels for therapeutic effect.
However, in cases of atherosclerosis leading to vessel narrowing, vasodilators cause systemic vasodilation and do not selectively target the inner ear vessels.
It is now widely accepted that treatment should focus on improving hemodynamics, increasing the deformability of red blood cells, and reducing blood viscosity to ensure the inner ear receives adequate oxygen and nutrients.
"Vasoactive agents" are medications developed based on this concept, derived from natural ginkgo biloba extracts or synthetically produced.
Red blood cells are about 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 hardened vessels more easily, and can act on blood vessels to reduce spasms.
Additionally, by preventing platelet aggregation, they can promote smoother blood flow.
6.
Tumor-Related Tinnitus: In the field of otolaryngology, unilateral tinnitus should raise suspicion for two types of tumors: nasopharyngeal carcinoma and acoustic neuroma.
This disease has also been mentioned in "A Casual Talk on Dizziness," and I will post it again.
- Acoustic Neuroma: The auditory nerve travels from the inner ear to the brainstem, with tumors most commonly occurring at the opening of the internal auditory canal, specifically at the cerebellopontine angle (CP angle).
Initially, patients may only experience gradual unilateral hearing loss or tinnitus.
This tumor grows very slowly, so although it compresses the vestibular nerve, central compensation prevents dizziness.
As the tumor enlarges and compresses blood vessels, it can lead to sudden hearing loss or dizziness, and symptoms can become very diverse as the disease progresses.
If the acoustic neuroma is confined to the internal auditory canal and is less than 1 cm, it is difficult to detect on CT scans; therefore, some have performed lumbar punctures to inject 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 internal auditory canal, which is known as "air CT." Its drawback is that patients may experience continuous 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 towards the cerebellum and 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
After classifying the causes of tinnitus, we find that many of the factors leading to 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 controlling noise levels in the work environment is crucial.
Early treatment of acute trauma-induced hearing loss is very effective, and it is even more important to avoid potentially harmful environments.
For metabolic tinnitus, in addition to managing underlying medical conditions, appropriate exercise and avoiding greasy 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 get louder during dizziness? Tinnitus associated with dizziness should raise suspicion for "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.
Additionally, tinnitus in Meniere's disease tends to worsen during dizziness.

2.
Is the work environment noisy? Have you worked in a high-noise environment for a long time? Have you experienced gunfire? Have you been injured by fireworks? As mentioned earlier, the human ear can tolerate noise levels up to 90 decibels, and exposure should not exceed eight hours per day.
When tinnitus occurs, it is essential to leave the noisy environment to prevent irreversible damage to the cochlear hair cells.
Standard ear protection can only block 30 to 40 decibels of noise and is ineffective against high-decibel noises like airplane engines, trains, or lathes.
3.
Have you had blood tests for cholesterol levels? Do you have anemia, high or low blood pressure, thyroid disease, diabetes, or atherosclerosis? Tinnitus caused by systemic vascular diseases is often bilateral, so it is essential to rule out these medical 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 after 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 lesions 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 the tinnitus diminishes or disappears when the neck is turned towards the affected side, it may be due to excessive pulsation in the neck vessels.
7.
Is the tinnitus related to breathing? General respiratory infections or Eustachian tube obstruction from flying can cause tinnitus.
Overactive Eustachian tubes can also lead to tinnitus, often accompanied by a sensation of ear vibration during breathing.
If the body bends down to tie shoelaces, the symptoms may immediately alleviate due to increased blood flow to the brain.

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Reply Date: 2004/12/27