Tympanic membrane scarring

Introduction Tympanic scarring produces tympanosclerosis, tympanic sclerosis, also known as tympanic glass degeneration, plaque-like collagen tissue is deposited subcutaneously in the tympanic mucosa, mostly in the tympanic membrane mucosa and ossicular, and is also known as calcified plaque on the tympanic membrane. To make the tympanic mucosa into a milky skin-like substance, covering the bones of the auditory bones, the oval window and the round window, and sticking to the bones, as if coated with a layer of film, involving the upper tympanic cavity is heavier, and the lower tympanic cavity is lighter. The hammer bone, the anvil bone, the tibia and the tendon are the most susceptible, so many people are deaf. This disease was discovered by Cassebohm in the 18th century, but it did not attract attention. It was not until the modern (1955) a large number of microsurgical operations.

Cause

1, common in acute necrotizing otitis media, due to a large number of destruction of mucociliary and gland, exudate can not be discharged, and later mechanicalized glass denaturation, and the formation of hardened plaque.

2, caused by chronic otitis media, accounting for about 10%. More common in young and middle-aged, more women. The reason why collagen tissue hyperplasia is induced may be related to the severe destruction of cilia and gland secretion by otitis media. The diseased tissue is the connective tissue of the middle blast, causing bone absorption. The structure is similar to keloid, but the cause is completely different. No allergies, no specific bacterial and viral infections. The plaque tissue under the microscope is divided into two types: 1 soft cheese-like shell and bone adhesion are not heavy, like onion skin can be peeled off. 2 solid, white lumps, tightly attached to the bone, difficult to remove, and produced shortly after removal. The plaque is a glass-like collagenous tissue, free of cells and blood vessels, covered with a very thin squamous epithelium. The ossicle necrosis is bitten by insects, often resulting in interruption and fixation of the ossicular chain. Harris (1961) divided the tympanic atherosclerosis into two types: 1 superficial sclerotic mucositis, which does not damage the deep layers of the mucosa and the cortex. 2 deep osteoclast mucositis can destroy deep bone. Some people object to this argument, arguing that tympanic hardening is an inactive disease, without destroying bone function, and the bone destruction that may occur is caused by the compression of ischemic necrosis. Ultrastructural electron microscopy showed collagen fibrosis, degeneration and calcium deposition in the extracellular space. Gibb (1976) reported plaque biochemical analysis with the main component calcium phosphate.

an examination

Related inspection

Tympanic membrane hearing test

Gibb reported 138 cases with a history of chronic otitis media, 80% had dry ears, and 84% had large perforation of the tympanic membrane. The scar on the surface of the tympanic membrane is gray-white plaques of different sizes. Sometimes, through the large perforations, there are gray-yellow hard plaques on the drum ring, the drumstick surface, the hammer stem and the tibia, which directly affect the tympanic membrane and ossicular activity. Pure tone audiometry is conductive deafness, the hearing level is 30 ~ 50dB, the impedance of the tympanic membrane is not perforated, the impedance of the tympanic membrane is normal, the acoustic diagram is As, and the mastoid X-ray shows interstitial or sclerotic mastoid.

Differential diagnosis

1. Ear sclerosis: Auricular sclerosis is a disease in which the bone layer of the bone is densely replaced by a spongy new bone rich in cells and blood vessels. It can be asymptomatic, only found in autopsy, most should be The lesions involve the hearing loss of the tibia or cochlea and clinical symptoms. The disease is more common in Caucasians. The incidence rate is significantly different. There are many young and middle-aged patients, and women are about 2.5 times more likely than men. Ear sclerosis has no history of otitis media, normal tympanic membrane, progressive deafness, and identification is not difficult.

2, adhesive otitis media: Adhesive otitis media (adhesive otitis media) is the formation of fibrous tissue hyperplasia or scar in the middle ear, is the result of previous middle ear inflammation. Often sick in childhood. Tympanic scarring and adhesive otitis media are difficult to identify, and sometimes rely on surgical exploration to confirm the diagnosis.

Gibb reported 138 cases with a history of chronic otitis media, 80% had dry ears, and 84% had large perforation of the tympanic membrane. The scar on the surface of the tympanic membrane is gray-white plaques of different sizes. Sometimes, through the large perforations, there are gray-yellow hard plaques on the drum ring, the drumstick surface, the hammer stem and the tibia, which directly affect the tympanic membrane and ossicular activity. Pure tone audiometry is conductive deafness, the hearing level is 30 ~ 50dB, the impedance of the tympanic membrane is not perforated, the impedance of the tympanic membrane is normal, the acoustic diagram is As, and the mastoid X-ray shows interstitial or sclerotic mastoid.

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