Tympanosclerosis

Synonym: Myringosclerosis

Tympanosclerosis is a condition in which there is calcification of tissue in the middle ear.^1,2 If extensive it may affect hearing. Tympanosclerosis may be classified as:

• Myringosclerosis - involving only the tympanic membrane.
• Intratympanic tympanosclerosis - involving other middle ear sites: the ossicular chain, or rarely the mastoid cavity.

There is increased fibroblast activity leading to collagen deposition. Calcium phosphate plaques form in the lamina propria of the tympanic membrane.

Most of the research studied patients with chronic otitis media and grommets (tympanostomy) rather than the general population:

• In children with glue ear treated with grommets, 23-40% have tympanosclerosis.^3,4,5,6
• Myringosclerosis (i.e. disease limited to the eardrum) seems to be the more common form.²

In one study of adults involving patients with carotid atherosclerosis and controls, tympanosclerosis was found in 38% of the atherosclerosis group and 11% of controls.⁷

The aetiology is not well understood. It may be a form of scarring related to chronic middle ear inflammation. Possible causative or associated factors are:

• Chronic otitis media (chronic suppurative otitis media and otitis media with effusion or 'glue ear')²
• Grommet (tympanostomy tube) insertion seems to increase the risk of tympanosclerosis.^4,8,9 The incidence of tympanosclerosis was higher if aspiration was performed prior to grommet insertion¹⁰ or if a larger grommet was used,¹¹ or where a grommet procedure was repeated.⁶
• In systemic sclerosis, findings similar to tympanosclerosis have been noted in some patients.¹²
• A possible link with carotid atheroma or atherosclerosis has been suggested.⁷
• An association with cholesteatoma is debateable - although the two conditions may co-exist.²

• Characteristic chalky white patches seen on inspection of the eardrum.^14,15
• Conductive hearing loss, in some cases.

Investigations are not usually required if the lesions are typical, not extensive and there is no suspicion of hearing loss or other middle ear disease.

• Pure tone audiometry - defines extent and type of hearing loss.
• Tympanometry - the tympanogram result can be affected by tympanosclerosis.¹⁶
• CT may help with diagnosis of disease within the middle ear cavity.¹⁷

The opaque or patchy white appearance of the eardrum is fairly unique and usually easy to identify. Cholesteatoma may look similar but the whiteness appears behind, rather than in/on the tympanum.^18,19

Hearing loss of a similar pattern may be found in:¹³

• Auditory canal obstruction due to wax or debris
• Otosclerosis
• Tympanic perforation
• Chronic otitis media (chronic suppurative otitis media and otitis media with effusion or 'glue ear')
• Cholesteatoma
• Glomus tumours (rare)

Treatment is only required if there is hearing loss.

• Hearing aids can be used, as with any form of conductive hearing loss.
• Surgery:
  • Surgery for tympanosclerosis involves excision of the sclerotic areas and reconstruction of the ossicular chain.
  • There are various techniques and some involve 2-stage surgery.^2,20
  • Reported success rates are variable.^21,22,23
  • Damage to the inner ear is a possible and serious complication, which can cause sensorineural deafness.²⁴

Conductive hearing loss:

• With myringosclerosis alone, hearing loss is uncommon, but may occur if the plaques are large or adhere to other structures (as the drum will be less compliant).
• Significant conductive hearing loss can occur with intratympanic disease.

According to studies following children with chronic otitis media treated with grommets:

• In most cases, tympanosclerosis probably does not cause significant hearing loss - however, the longest follow-up was for 10 years, so there is no information as to possible late effects.^8,25
• The sclerotic changes seem to stabilise by 3 years.⁶
• The sclerotic changes do not seem to resolve with time.^6,26