Introduction:
Tympanosclerosis is a pathologic condition that causes sclerotic patches in the middle ear. There are two types of tympanosclerosis:
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Myringosclerosis - Tympanosclerosis that is limited to the tympanic membrane is called myringosclerosis.
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Intratympanic Tympanosclerosis - Tympanosclerosis that affects the middle ear is called intratympanic tympanosclerosis.
What Is Myringosclerosis?
The ear is divided into three parts:
A tympanic membrane (ear drum) separates the outer and middle ears. As soon as the air enters the ear canal, it causes vibrations in the tympanic membrane. These vibrations get amplified by the ossicles in the middle ear. The amplified waves are transformed into electrical energy and travel along the nerve to reach the brain.
Myringosclerosis:
The collagen fibers in the tympanic membrane are replaced by calcium due to chronic inflammatory reactions resulting in myringosclerosis. In addition, the hyperoxic condition in the middle ear generates free oxygen radicals, which result in sclerotic (rigid or hard) deposits on the tympanic membrane. The damage created by free oxygen radicals in the formation of myringosclerosis is increased by the lower concentration of antioxidants.
What Are the Symptoms of Myringosclerosis and How to Identify It?
Myringosclerosis is usually asymptomatic and may cause conductive or mixed hearing loss (conductive and sensorineural hearing loss) as more plaque gets deposited on the tympanic membrane. In contrast, a small amount of plaque deposits makes no difference in hearing. When large areas of the tympanic membrane are affected by calcification, it impairs the movement of the tympanic membrane, which results in hearing loss. Myringosclerosis affecting the anterior half of the tympanic membrane leads to more mild-to-moderate hearing loss in patients than in the posterior half.
What Are the Causes of Myringosclerosis?
1. Ventilation tube (tympanostomy tube) insertion is one of the significant causes of myringosclerosis. Otitis media in children usually resolves easily, but if it is persistent, myringotomy (small incision in the tympanic membrane) with ventilator tube insertion is the treatment. The ventilator tube insertion helps prevent fluid reaccumulation. There are two types of ventilator tubes:
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Short-term (6 to 12 months).
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Long-term (more than a year).
It is made of plastic, metal, or silicone. Many children do not require additional therapy after myringotomy with the ventilation tube insertion because the eustachian tube's development helps drain the fluid.
2. Trauma to the tympanic membrane during any surgical procedure.
3. Genetics.
4. Increased formation of oxygen free radicals.
5. Recurrent and chronic inflammation lead to healed inflammation or scar tissue of the middle ear and tympanic membrane, resulting in myringosclerosis.
6. Any infection of the middle ear may contribute to myringosclerosis.
How to Prevent Myringosclerosis?
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Oxygen-free radicals are one of the main reasons for myringosclerosis; therefore, antioxidants are given to reduce the free radicals.
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Incisional myringotomy (incision at the tympanic membrane) increases the chances of myringosclerosis, so radiofrequency myringotomy is performed, thus reducing its occurrence.
What Drugs Are Used to Prevent the Formation of Myringosclerosis?
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Topical application of vitamin E.
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N-acetylcysteine.
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Sodium thiosulphate
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Ciprofloxacin.
What Risk Should Factors Be Considered?
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Severe otitis media with effusion.
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Type 2 ventilation tube.
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Post ventilator tube perforation.
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Otorrhea.
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Frequent ventilator tube insertion.
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In the four quadrants of the tympanic membrane, the anteroinferiorquadrant has maximum risk (posteroinferiorquadrant - minimum risk).
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Patients diagnosed with tympanosclerosis have increased triglycerides, total cholesterol, low-density lipoprotein, and homocysteine.
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Age.
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Children have a high incidence of myringosclerosis due to immature eustachian tubes.
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The function of the eustachian tube is reduced in older adults, which often leads to otitis media with effusion. They usually have sensorineural hearing loss (hearing loss due to damage to the inner ear's nerves).
What Are the Investigations to Be Done?
In typical cases, no investigations are done. However, for patients with conductive hearing loss, the following investigations are prescribed:
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Audiometry - In cases of hearing loss, pure tone audiometry tests are done using pure tone (single frequency) through earphones to measure the threshold.
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Otoscopy - A procedure used to visualize the structures of the middle ears, tympanic membrane, and external acoustic canal. Cholesteatoma is similar to myringosclerosis, but the lesion is located behind the tympanic membrane.
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Tympanometry - This device helps in providing information and function of the structures and the fluid presence in the middle ear.
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Tympanometry HRCT - HRCT (high-resolution computed tomography) of the temporal bone is taken. It reveals eardrum thickening and calcification.
What Are the Treatment Options?
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Hearing Aids - A hearing aid is a device that enhances the sound entering the ear though it does not make your hearing perfect. It is helpful for patients with conductive hearing loss.
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Surgical Procedure - Tympanoplasty is the surgical procedure done. The white deposits are removed, and the structures are reconstructed in the surgery. This procedure results in hearing improvement. Usually, hearing loss is less in myringosclerosis, but if the plaques are attached to the adjacent structures, there may be hearing loss to some extent. The reconstruction of the tympanic membrane and the ossicles depends on the extent of surgical resection. As it is a progressive disease, new plaque deposits may occur even after surgical treatment. After the surgical removal of the white deposits, the hearing results were good in patients with tympanic membrane perforation.
Conclusion:
Myringosclerosis affects the tympanic membrane function, which results in mild-to-moderate hearing loss in some patients. Thus, myringosclerosis is an irreversible condition. Myringosclerosis can be managed surgically, but there may be a recurrence in the future. Hence, it is important to go for a follow-up regularly to prevent the recurrence of myringosclerosis.
