para>Progression may accelerate during pregnancy.
Some women first notice hearing loss at this time.
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Prevalence
- Histologic form: 4 " ô8% among U.S. Caucasian population; 1% among African Americans
- Histologic form: U.S. Caucasian population: 5,000/100,000; African Americans: 1,000/100,000
- Clinical form: 0.3 " ô0.4%
ETIOLOGY AND PATHOPHYSIOLOGY
- Unknown
- Fluoride metabolism may play a role; fluoride treatment is under investigation, as early results demonstrate improved hearing outcomes.
Genetics
- 60% of those affected give positive family history.
- Appears to be transmitted by autosomal dominant gene with variable expressivity
RISK FACTORS
Unknown é á
COMMONLY ASSOCIATED CONDITIONS
- Van der Hoeve syndrome (rare triad of osteogenesis imperfecta, blue sclera, and otospongiosis)
- Tinnitus, usually low frequency
DIAGNOSIS
HISTORY
- Progressive conductive hearing loss, usually with well-preserved speech discrimination
- Patients often are soft-spoken and aware that they seem to hear better in noisy environments.
PHYSICAL EXAM
Schwartze sign: reddish hue in front of oval window; on promontory at otoscopic exam é á
DIFFERENTIAL DIAGNOSIS
- Chronic suppurative otitis media
- Serous otitis media
- External auditory canal occlusion
- Meni â Ęre disease
- Ossicular chain disruption
- Congenital fixation of stapes
- Paget disease of bone
- Presbycusis
- Advanced otosclerosis mimics sensorineural deafness.
DIAGNOSTIC TESTS & INTERPRETATION
Coaxial or CT scan sometimes helpful é á
Diagnostic Procedures/Other
Tuning fork and audiometric testing for conductive and/or sensorineural hearing loss é á
- Will lateralize to more impaired ear with Weber test
- Conductive hearing loss; may be as severe as the 60 dB maximum
- May have sensorineural hearing loss with cochlear involvement
- Carhart notch: a dip in bone conductive threshold at 2,000 Hz on audiometric testing
Test Interpretation
- Gross
- Off-white to reddish bone formation, most often located anterior to the oval window and extending to involve the stapedial footplate; sometimes covers entire oval window (obliterative); may be found anywhere in otic capsule
- Bilateral in 75% of patients
- Micro
- Spongy-appearing bone with increased vascular spaces
- Osteoblasts and osteoclasts are plentiful.
ALERT
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TREATMENT
MEDICATION
No specific drug therapy, but sodium fluoride, bisphosphonates, vitamin D, and calcium gluconate have been tried, especially in cases of predominantly sensorineural hearing loss. é á
SURGERY/OTHER PROCEDURES
- Surgical correction (stapedotomy/stapedectomy)
- Usually involves mobilization or removal of the stapedial footplate with placement of a stapes prosthesis
- Recent procedural innovations have involved use of lasers.
- Cochlear implantation may achieve better results in advanced cases (2)[B].
- A systematic review in 2014 supports initial stapedotomy in advanced cases with cochlear implantation reserved for those with unsatisfactory improvement in hearing and speech recognition (3)[A].
- Relative indications for surgery include negative Rinne test (air " ôbone audiometric gap at least 20 dB) and bilateral involvement.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- No restrictions on activity
- Hearing aids
Patient Monitoring
Interval audiometric testing é á
PATIENT EDUCATION
- Because speech discrimination is usually preserved, patients should be advised of the possible benefit from hearing aids as an alternative or adjunct to surgery.
- Mayo Foundation for Medical Education and Research, Section of Patient and Health Education, Sieber Subway, Rochester, MN 55905; (507) 284-8140
- MedlinePlus. Otosclerosis: http://www.nlm.nih.gov/medlineplus/ency/article/001036.htm
PROGNOSIS
- Progressive hearing loss if not treated
- Surgery closes air " ôbone gap to 10 dB in >90% of cases (4)[B].
- Surgical results are durable in case series with >30 years of follow-up (5)[B].
- Some decline over time and may benefit from repeat surgical intervention.
COMPLICATIONS
Surgical risks include chorda tympani nerve injury, tympanic membrane laceration, ossicular chain disruption, otitis media and externa, labyrinthitis, granuloma formation, perilymph fistulas, and total deafness ( "dead ear " Ł). é á
REFERENCES
11 Meyer é áTA, Lambert é áPR. Primary and revision stapedectomy in elderly patients. Curr Opin Otolaryngol Head Neck Surg. 2004;12(5):387 " ô392.22 Berrettini é áS, Burdo é áS, Forli é áF, et al. Far advanced otosclerosis: stapes surgery or cochlear implantation? J Otolaryngol. 2004;33(3):165 " ô171.33 van Loon é áMC, Merkus é áP, Smit é áCF, et al. Stapedotomy in cochlear implant candidates with far advanced otosclerosis: a systematic review of the literature and meta-analysis. Otol Neurotol. 2014;35(10):1707 " ô1714.44 Vincent é áR, Sperling é áNM, Oates é áJ, et al. Surgical findings and long-term hearing results in 3,050 stapedotomies for primary otosclerosis: a prospective study with the otology-neurotology database. Otol Neurotol. 2006;27(8 Suppl 2):S25 " ôS47.55 Karhuketo é áTS, Lundmark é áJ, Vanhatalo é áJ, et al. Stapes surgery: a 32-year follow-up. J Otorhinolaryngol Relat Spec. 2007;69(5):322 " ô326.
ADDITIONAL READING
- Derks é áW, De Groot é áJA, Raymakers é áJA, et al. Fluoride therapy for cochlear otosclerosis? An audiometric and computerized tomography evaluation. Acta Otolaryngol. 2001;121(2):174 " ô177.
- Ealy é áM, Smith é áRJ. Otosclerosis. Adv Otorhinolaryngol. 2011;70:122 " ô129.
- Marchese é áMR, Paludetti é áG, De Corso é áE, et al. Role of stapes surgery in improving hearing loss caused by otosclerosis. J Laryngol Otol. 2007;121(5):438 " ô443.
SEE ALSO
Hearing Loss é á
CODES
ICD10
- H80.90 Unspecified otosclerosis, unspecified ear
- H80.20 Cochlear otosclerosis, unspecified ear
- H80.00 Otosclerosis w oval window, nonobliterative, unsp ear
- H80.10 Otosclerosis involving oval window, obliterative, unsp ear
- H80.81 Other otosclerosis, right ear
- H80.01 Otosclerosis w oval window, nonobliterative, right ear
- H80.02 Otosclerosis w oval window, nonobliterative, left ear
- H80.03 Otosclerosis involving oval window, nonobliterative, bi
- H80.11 Otosclerosis involving oval window, obliterative, right ear
- H80.12 Otosclerosis involving oval window, obliterative, left ear
- H80.13 Otosclerosis involving oval window, obliterative, bilateral
- H80.21 Cochlear otosclerosis, right ear
- H80.22 Cochlear otosclerosis, left ear
- H80.91 Unspecified otosclerosis, right ear
- H80.80 Other otosclerosis, unspecified ear
- H80.82 Other otosclerosis, left ear
- H80.83 Other otosclerosis, bilateral
- H80.93 Unspecified otosclerosis, bilateral
- H80.92 Unspecified otosclerosis, left ear
- H80.23 Cochlear otosclerosis, bilateral
ICD9
- 387.9 Otosclerosis, unspecified
- 387.2 Cochlear otosclerosis
- 387.0 Otosclerosis involving oval window, nonobliterative
- 387.1 Otosclerosis involving oval window, obliterative
- 387.8 Other otosclerosis
SNOMED
- Otosclerosis (disorder)
- Cochlear otosclerosis
- Nonobliterative otosclerosis involving oval window (disorder)
- Obliterative otosclerosis involving oval window (disorder)
CLINICAL PEARLS
- The audiometric signature of otosclerosis is a dip in conductive hearing at 2,000 Hz.
- Hearing aids are helpful in patients with preserved speech discrimination.
- Bilateral involvement and an air " ôbone audiometric gap of ≥20 dB are indications for surgery.
- Surgical correction has a high success rate with good long-term durability.