Tympanosclerosis

Definition and epidemiology

Tympanosclerosis is a repair process in which hyalinisation and calcification develop in connective tissue after recurrent or chronic middle-ear infections. The superficial form involving only the eardrum is called myringosclerosis; the widespread form involving the middle-ear cavity and ossicles is called tympanosclerosis.

It is common in ears with chronic otitis media and a history of ventilation tubes. Myringosclerosis limited to the drum is quite common and usually does not affect hearing; the widespread form encasing the ossicles can cause hearing loss (Gibb & Pang, 1994).

When the pathological plaques restrict movement of the ossicular chain responsible for sound conduction in the middle ear (especially the stapes), a conductive hearing loss appears.

Symptoms and signs

Myringosclerosis limited to the eardrum usually causes no symptoms; on examination it appears as white, chalky plaques on the drum and is often found incidentally.

In the widespread form involving the middle ear and ossicles, slowly progressive, painless conductive hearing loss is prominent. Some patients may have a sense of ear fullness and mild tinnitus.

There is usually a history of recurrent ear infections, discharge or tubes. Because there is no active infection, pain and discharge are not expected.

Causes and risk factors

The main cause is an excessive repair response to previous middle-ear infections. A history of chronic and recurrent otitis media is the most important risk factor.

Ventilation tubes placed in childhood can increase myringosclerosis; however, this is usually a cosmetic finding that does not affect hearing (Asiri et al., 1999).

Oxidative stress and recurrent inflammation are thought to play a role in plaque formation (Bhaya et al., 1993).

Audiological and clinical assessment

The first step in diagnosis is otoscopic/microscopic examination; the characteristic white plaques on the eardrum can be seen directly. However, involvement inside the middle ear cannot always be assessed on examination.

• Pure-tone audiometry: determines the degree of conductive loss and the air-bone gap.
• Tympanometry: a normal or low-peaked curve depending on ossicular stiffness; may reflect restricted mobility.
• Acoustic reflexes: may be lost with ossicular involvement.
• High-resolution CT: shows the location and extent of plaques before surgery.

Tympanosclerosis must be distinguished from otosclerosis and ossicular chain discontinuity, which give similar findings; the definitive distinction often becomes clear during surgery.

Treatment and audiological rehabilitation

Plaques limited to the drum that do not affect hearing need no treatment; they are simply monitored. If there is active infection, that is treated first.

For middle-ear involvement causing hearing loss, surgery (tympanoplasty, and where needed ossicular chain repair or stapes surgery) may be considered. However, because of the extent of the plaques and a tendency to recur, results are more variable than in otosclerosis; the decision rests with the physician.

When surgery is not suitable or preferred, hearing aids are a safe and effective option; they usually give very good results in conductive losses.

Impact on quality of life and advice

When hearing loss stays mild to moderate, its impact on quality of life may be limited; but if untreated, communication difficulty and social withdrawal can develop.

Protecting ear health, treating infections promptly and regular audiological check-ups are important. Periodic review of hearing-aid settings (fitting) benefits users.