Tympanosclerosis

Signs and symptoms

Myringosclerosis rarely causes any symptoms. Tympanosclerosis, on the other hand, can cause significant hearing loss or chalky, white patches on the middle ear or tympanic membrane.

Causes

The aetiology for tympanosclerosis is not extensively understood. There are several probable factors which could result in the condition appearing, including:

• Long term otitis media (or 'glue ear')
• Insertion of a tympanostomy tube. If aspiration is performed as part of the insertion, the risk of tympanosclerosis occurring increases. Risk also increases if a larger tube is used, or if the procedure is repeated.
• Atherosclerosis
• There is ongoing research as to whether or not cholesteatoma is associated with tympanosclerosis. If there is an association, it is likely that the two conditions co-exist.

Pathophysiology

Increased fibroblast activity results in deposition of collagen. Calcium phosphate plaques then form in the lamina propria of the tympanic membrane.

Diagnosis

If lesions are typical, non-extensive and with no detriment to hearing, investigation into the condition is rarely required. Audiometry is used to determine the extent of hearing loss, if any. Tympanometry produces tympanograms which can be different when tympanosclerosis is present. Computerised tomography (CT) can be used to determine if disease is present in the middle ear. Whilst hearing loss is a common symptom in many diseases of the ear, for example in otosclerosis (abnormal bone growth in the ear), the white, chalky patches on the tympanic membrane are fairly characteristic of tympanosclerosis. Cholesteatoma is similar in appearance but the whiteness is behind the tympanic membrane, rather than inside.

Classification

Myringosclerosis refers to a calcification only within the tympanic membrane and is usually less extensive than intratympanic tympanosclerosis, which refers to any other location within the middle ear such as the ossicular chain, middle ear mucosa or, less frequently, the mastoid cavity.

Treatment

Hearing aids are a common treatment for hearing loss disorders. A more specific treatment is surgical, involving excision of the sclerotic areas and then further repair of the ossicular chain. There are several techniques, sometimes involving two surgeries; success rates are, however, variable. Damage to the inner ear as a result of surgical procedures is a possible and serious concern, as it can result in forms of sensorineural deafness.

Prognosis

In most cases, tympanosclerosis does not cause any recognisable hearing loss up to ten years after the initial disease onset. Sclerotic changes seem to stabilise, but not resolve or dissolve, after 3 years.

Epidemiology

Myringosclerosis seems to be more common than tympanosclerosis. Most research has not been conducted upon the general, healthy population, but rather those with otitis media or patients who have had tympanostomy tubes in prior procedures. Of the children studied who had 'glue ear', and who were treated with tympanostomy tubing, 23-40% of cases had tympanosclerosis. One study suggested that people with atherosclerosis were more likely to have tympanosclerosis than otherwise healthy individuals.

References

References

1. (May 2001). "A study of inflammatory mediators in the human tympanosclerotic middle ear". Archives of Otolaryngology–Head & Neck Surgery.
2. (December 1999). "Tympanosclerosis: review of literature and incidence among patients with middle-ear infection". The Journal of Laryngology and Otology.
3. (April 2001). "Meta-analysis of tympanostomy tube sequelae". [[Otolaryngology–Head and Neck Surgery]].
4. Johnston LC. (July 2004). "Tympanic membrane abnormalities and hearing levels at the ages of 5 and 6 years in relation to persistent otitis media and tympanostomy tube insertion in the first 3 years of life: a prospective study incorporating a randomized clinical trial". Pediatrics.
5. Browning, George G.. (2010-10-06). "Grommets (ventilation tubes) for hearing loss associated with otitis media with effusion in children". The Cochrane Database of Systematic Reviews.
6. (August 1989). "Aspiration of middle ear effusions prior to grommet insertion an etiological factor in tympanosclerosis". The Journal of Otolaryngology.
7. (March 1991). "The mini-grommet and tympanosclerosis". The Journal of Laryngology and Otology.
8. Maw AR. (August 1991). "Development of tympanosclerosis in children with otitis media with effusion and ventilation tubes". The Journal of Laryngology and Otology.
9. (June 2004). "Is carotid stenosis correlated with tympanosclerosis". International Angiology.
10. Onusko E. (November 2004). "Tympanometry". American Family Physician.
11. (August 1983). "High-resolution computed tomography of the middle ear and mastoid. Part II: Tubotympanic disease". Radiology.
12. (September 2003). "Differential diagnosis and treatment of hearing loss". American Family Physician.
13. (May 2004). "An analysis of the single-stage tympanoplasty with over-underlay grafting in tympanosclerosis". Otology & Neurotology.
14. (November 2002). "Stapedotomy for tympanosclerotic stapes fixation: is it safe and efficient? A review of 68 cases". Otology & Neurotology.
15. Bellucci RJ. (August 1985). "Cochlear hearing loss in tympanoplasty". [[Otolaryngology–Head and Neck Surgery]].
16. (March 1997). "Myringotomy and ventilation tube insertion: a ten-year follow-up". The Journal of Laryngology and Otology.
17. (September 2005). "Natural course of tympanic membrane pathology related to otitis media and ventilation tubes between ages 8 and 18 years". Otology & Neurotology.
18. (May 1995). "Tympanostomy tube sequelae in children with otitis media with effusion: a three-year follow-up study". Brazilian Journal of Otorhinolaryngology.