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;Pregnancy: There is no strong evidence why pregnancy worsens hearing loss in some patients with otosclerosis.<ref name="pmid6883784">{{cite journal| author=Gristwood RE, Venables WN| title=Pregnancy and otosclerosis. | journal=Clin Otolaryngol Allied Sci | year= 1983 | volume= 8 | issue= 3 | pages= 205-10 | pmid=6883784 | doi=10.1111/j.1365-2273.1983.tb01428.x | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6883784  }} </ref>
;Pregnancy: There is no strong evidence why pregnancy worsens hearing loss in some patients with otosclerosis.<ref name="pmid6883784">{{cite journal| author=Gristwood RE, Venables WN| title=Pregnancy and otosclerosis. | journal=Clin Otolaryngol Allied Sci | year= 1983 | volume= 8 | issue= 3 | pages= 205-10 | pmid=6883784 | doi=10.1111/j.1365-2273.1983.tb01428.x | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6883784  }} </ref>
;Measles: RNA of measles virus was detected at the footplate of stapes in otosclerotic patients , suggesting its role in casuing it, while incidence has reduced significantly in vaccinated populations.<ref name="pmid18235207">{{cite journal| author=Niedermeyer HP, Arnold W| title=Otosclerosis and measles virus - association or causation? | journal=ORL J Otorhinolaryngol Relat Spec | year= 2008 | volume= 70 | issue= 1 | pages= 63-9; discussion 69-70 | pmid=18235207 | doi=10.1159/000111049 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18235207  }} </ref>
;Measles: RNA of measles virus was detected at the footplate of stapes in otosclerotic patients , suggesting its role in casuing it, while incidence has reduced significantly in vaccinated populations.<ref name="pmid18235207">{{cite journal| author=Niedermeyer HP, Arnold W| title=Otosclerosis and measles virus - association or causation? | journal=ORL J Otorhinolaryngol Relat Spec | year= 2008 | volume= 70 | issue= 1 | pages= 63-9; discussion 69-70 | pmid=18235207 | doi=10.1159/000111049 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18235207  }} </ref>
;Trauma and Major surgeries also cause otosclerosis.
;Trauma and Major surgeries: also cause otosclerosis.


==[[Differentiating otosclerosis from other diseases|Differentiating otosclerosis from other diseases]]==
==[[Differentiating otosclerosis from other diseases|Differentiating otosclerosis from other diseases]]==

Revision as of 22:21, 11 November 2020

Wikidoc


Otosclerosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] CSN, M.D. Christina Ninan, M.D.


Synonyms and keywords: Otospongiosis

Overview

Otosclerosis is a word derived from the Greek word "sklērós" meaning hardening and oto meaning ear. Otosclerosis is a disorder in which the footplate of the stapes is replaced by an abnormal bone, thereby affecting sound transmission to the inner ear at the level of the oval window.[1] osseous dyscrasia limited to the temporal bone that results in slow, progressive conductive hearing loss(emedicine) (CT) scanning of the temporal bone can often demonstrate foci of demineralization in the otic capsule in cases of cochlear otosclerosis

These changes can occur at many locations in the inner ear. The majority of cases consist of changes in the oval window, but they have also been described in the round window, cochlear apex, posterior to the oval window, posterior and anterior wall of the internal auditory canal (IAC), cochlear aqueduct, semicircular canals, and within the stapes footplate.


Historical perspective

  • 1704:Antonio Maria Valsalva identified fixation of stapes as a cause of hearing loss[2]
  • 1841:Toyn bee stated, "osseous ankylosis of the stapes to the fenestra ovalis as one of the causes of deafness".[3]
  • 1876:Johannes Kessel described stapes surgery as the treatment.[4]
  • 1930-1950: Used Julius Lempert’s single-stage fenestration of stapes as treatment.[5]
  • 1956:John Shea modernized stapedectomy.[6]

Classification

Based on Symons/fanning grading system[7]
  • Grade 1: Fenestral Otosclerosis
  • Grade 2: Cochlear Otosclerosis
    • Grade 2A:Basal cochlear turn Otosclerosis
    • Grade 2B:Middle/Apical turn Otosclerosis
    • Grade 2C:Both Basal and Middle/apical Otosclerosis
  • Grade 3:diffuse confluent cochlear involvement (with or without fenestral involvement)

Embryology

Table explains the embryological process for the development of bony labyrinth

Gestational week Developmental process
4th week
  • Development of otic canal from mesenchyme of otic vesicle by forming an otic capsule around it
8th week
  • Initiation of the cartilaginous framework
16th week
  • Endochondrial replacement of the cartilaginous framework.

In certain cases, completion of the third stage of bone formation doesn't occur leading to cartilages between bony structures. During labyrinth bone formation, the anterior to the oval window is usually the last area to develop. This area is the most common site for otosclerosis.

Pathophysiology

Accumulation of bone deposits because of increased bone remodeling which is bone resorption followed by bone deposition in the otic capsule result in otosclerosis. Audiological findings are directly proportionate to the extent of bone remodeling.[8] Bone remodeling happens in 3 phases:

Phase Mechanism of action
Otospongiosis Increase in both osteoclast activity and microvascularity
Transitional phase begins with deposits of spongy bone by osteoblasts in areas of previous bone reabsorption
Otosclerotic phase characterized by spongy bone deposits developing into dense bone that narrows the microcirculation previously developed in the otospongiosis phase

The lesions occur mostly in the anterior to the oval window by calcifying of annular ligament or by involving stapes footplate (80%). While 30% of cases have the lesion at the round window,21% have it at pericochlear region, and 19% at the anterior segment of the internal auditory canal.[9]

Etiology

Though the exact cause of otosclerosis is unknown, several etiology that could cause it are the following:

Embryological Cause
During the maturation of the otic capsule of the labyrinth, certain places skip the complete conversion to endochondral, leading to irregularly laid spongy bone. This most commonly is seen at fissula ante fenestram.[10]
Genetic Cause
Studies have been conducted and found Type 1 collagen gene(COL1A1), a component essential for bone metabolism plays a role in otosclerosis. TGF-beta 1(BMP 2 and BMP 4 gene and Angiotensin II (AGT M235T and ACE I/D genes) are also found associated with otosclerosis. Other genetic causes for otosclerosis include sex hormones, autoimmune reaction, human leucocyte antigen, inflammatory and regulatory cytokines, parathyroid hormone, and expression of parathyroid hormone-related peptides receptors, and oxidative stress[11][12][13][14]
Gender
Women are more likely to have otosclerosis than men , suggesting the role of sex hormones.[15]
Ethinicity
Otosclerosis is more common in Caucasians and Japanese[16]
Age
Even though otosclerosis could be seen in patients at their twenties and thirties, it usually causes hearing loss only in or after their forties.
Pregnancy
There is no strong evidence why pregnancy worsens hearing loss in some patients with otosclerosis.[17]
Measles
RNA of measles virus was detected at the footplate of stapes in otosclerotic patients , suggesting its role in casuing it, while incidence has reduced significantly in vaccinated populations.[18]
Trauma and Major surgeries
also cause otosclerosis.

Differentiating otosclerosis from other diseases

Conditions mimicking Otosclerosis
  • Serous otitis media
  • Adhesive otitis media
  • Congenital stapes fixation
  • Meniere disease
  • Tympanosclerosis
  • Attic fixation of head of the malleus
  • Ossicular discontinuity

Epidemiology and demographics

  • Greater preponderance in women compared to men in a ratio of 2:1.[19]
  • Even though the disease begins in the second and third decade of life, it doesn't result in hearing loss until the fourth decade.[20]
  • Clinical prevalence of otosclerosis is found to be higher in Caucasians by 0.04%-1% while the histological incidence of otosclerosis increases to 10% in the same.[21].The incidence of histological otosclerosis is 1% and 5% in African and Asian population respectively.[22]
  • Autosomal dominant mode of inheritance with incomplete penetrance in certain cases.

Risk Factors

Genetic factor
Otosclerosis is an autosomal dominant disease with incomplete penetrance. When 60% of patients were found with family history, 40-50% of patients have it with variable patterns of inheritance. But hearing loss in otosclerosis is found only with family history of the same.[10]
Hormonal conditions
Puberty, pregnancy, and menopause increase the occurrence of hearing loss in pre-existing otosclerosis.[23]
Measles
Persistent measles virus infection of stapes footplate results in activated osteoclast and inflammatory pathways by TNF-alpha mRNA. The protective function of osteoprotegerin at the otic capsule is inhibited by TNF-alpha and its action on RANK production[14]

Screening

Clinincal associations and Complications

Clinical presentaion

Patients present with the following:

  • Most cases are asymptomatic and diagnosed as an incidental finding in temporal autopsies.
  • Bilateral(80%) or unilateral involvement earlier in the disease.[24]
  • Progressive hearing loss, which might worsen with lower tone and frequencies like male voices and vowels.
  • vertigo(10%) [25]
  • tinnitis (50%)[25]
  • Schwartz sign or flemingo's pink sign(not necessary for diagnosis): redness along the promontory of tymphanic membrane on otoscopic examination[26]

Diagnosis

Tuning fork[27]

  • Pro of using a tuning fork for diagnosis
    • Negative Rinne test
    • Weber test lateralizes to the ear with severe conductive loss.
  • Con of using tuning fork for diagnosis
    • Rinne test cannot differentiate between sensorineural hearing loss and normal hearing loss.
    • Weber test's inability to differentiate a bilateral hearing loss.

Whisper test[27]

Audiometry and tympanometry

  • Caharts notch: Bone conduction depression in threshold at 2000Hz. After stapedectomy caharts notch diappears.
  • Tympanometry normal at early disease. In severe cases, flattening and stiffening of curve representing low complaince of ossicular chain and tympanic membrane. Good test to differentiate between otosclerosis and pathologies with low resonance.

CT Imaging

  • High resolution computed tomography (CT) of the temporal bones is the imaging technique of choice in the diagnosis of otosclerosis. [28]
  • However, preoperative CT has little to add in establishing otosclerosis diagnosis and may not even be necessary to confirm diagnosis. [29]
  • CT is recommended to be reserved for those patients with presumed additional abnormalities, for specific preoperative planning, or for legal necessity.[29]
  • finding: increased bony radiolucency in the otic capsule around the anterior footplate, thickening of the stapes, and widening of the oval window.[28]

Early sign: halo sign; demineralized area outlining the cochlea.

Treatment

SAMPLE

  • USMLE STEP 1
  • USMLE STEP 2
    • USMLE STEP 2 CK
    • USMLE STEP 2 CS
  • USMLE STEP 3
    • USMLE STEP 3 MCQ
    • USMLE STEP 3 CCS92F + atrial fibrillation + numbness/tingling of her right leg; where is the stroke lesion?
  1. left or right side of the brain?
à answer = left (contralateral).
  1. medial or lateral cerebral hemisphere?
àanswer = medial (homunculus for lower limb is

medial, upper limb and face are lateral).

  1. anterior or posterior to the central sulcus?
ànswer = posterior (primary sensory cortexis posterior; primary motor is anterior))
  1. ↑ Rajput MSA, Arain AA, Rajput AA, Adeel M, Suahil A, Awan MS (2020). "Otosclerosis: Experience With Stapes Surgery". Cureus. 12 (5): e7927. doi:10.7759/cureus.7927. PMC 7265776 Check |pmc= value (help). PMID 32499972 Check |pmid= value (help).
  2. ↑ Makarem AO, Hoang TA, Lo WW, Linthicum FH, Fayad JN (2010). "Cavitating otosclerosis: clinical, radiologic, and histopathologic correlations". Otol Neurotol. 31 (3): 381–4. doi:10.1097/MAO.0b013e3181d275e8. PMC 2880664. PMID 20195188.
  3. ↑ Nazarian R, McElveen JT, Eshraghi AA (2018). "History of Otosclerosis and Stapes Surgery". Otolaryngol Clin North Am. 51 (2): 275–290. doi:10.1016/j.otc.2017.11.003. PMID 29502722.
  4. ↑ Wielgosz R, Mroczkowski E (2008). "[History of endaural surgery]". Otolaryngol Pol. 62 (3): 348–50. doi:10.1016/S0030-6657(08)70269-5. PMID 18652164.
  5. ↑ Pietruski J (1998). "[Juliusz Lempert (1890-1959): the author of the fenestration technique]". Otolaryngol Pol. 52 (3): 341–6. PMID 9760779.
  6. ↑ Cheng HCS, Agrawal SK, Parnes LS (2018). "Stapedectomy Versus Stapedotomy". Otolaryngol Clin North Am. 51 (2): 375–392. doi:10.1016/j.otc.2017.11.008. PMID 29397948.
  7. ↑ Lee TC, Aviv RI, Chen JM, Nedzelski JM, Fox AJ, Symons SP (2009). "CT grading of otosclerosis". AJNR Am J Neuroradiol. 30 (7): 1435–9. doi:10.3174/ajnr.A1558. PMC 7051554 Check |pmc= value (help). PMID 19321627.
  8. ↑ Wiatr A, Składzień J, Świeży K, Wiatr M (2019). "A Biochemical Analysis of the Stapes". Med Sci Monit. 25: 2679–2686. doi:10.12659/MSM.913635. PMC 6475125. PMID 30975972.
  9. ↑ Arnold W (2007). "Some remarks on the histopathology of otosclerosis". Adv Otorhinolaryngol. 65: 25–30. doi:10.1159/000098665. PMID 17245019.
  10. ↑ 10.0 10.1 Rudic M, Keogh I, Wagner R, Wilkinson E, Kiros N, Ferrary E; et al. (2015). "The pathophysiology of otosclerosis: Review of current research". Hear Res. 330 (Pt A): 51–6. doi:10.1016/j.heares.2015.07.014. PMID 26276418.
  11. ↑ Bittermann AJ, Wegner I, Noordman BJ, Vincent R, van der Heijden GJ, Grolman W (2014). "An introduction of genetics in otosclerosis: a systematic review". Otolaryngol Head Neck Surg. 150 (1): 34–9. doi:10.1177/0194599813509951. PMID 24170657.
  12. ↑ Van Den Bogaert K, Govaerts PJ, Schatteman I, Brown MR, Caethoven G, Offeciers FE; et al. (2001). "A second gene for otosclerosis, OTSC2, maps to chromosome 7q34-36". Am J Hum Genet. 68 (2): 495–500. doi:10.1086/318185. PMC 1235283. PMID 11170898.
  13. ↑ Thys M, Van Den Bogaert K, Iliadou V, Vanderstraeten K, Dieltjens N, Schrauwen I; et al. (2007). "A seventh locus for otosclerosis, OTSC7, maps to chromosome 6q13-16.1". Eur J Hum Genet. 15 (3): 362–8. doi:10.1038/sj.ejhg.5201761. PMID 17213839.
  14. ↑ 14.0 14.1 Karosi T, Jókay I, Kónya J, Szabó LZ, Pytel J, Jóri J; et al. (2006). "Detection of osteoprotegerin and TNF-alpha mRNA in ankylotic Stapes footplates in connection with measles virus positivity". Laryngoscope. 116 (8): 1427–33. doi:10.1097/01.mlg.0000225928.35838.e5. PMID 16885748.
  15. ↑ Ben Arab S, Besbes G, Hachicha S (2001). "[Otosclerosis in populations living in northern Tunisia: epidemiology and etiology]". Ann Otolaryngol Chir Cervicofac. 118 (1): 19–25. PMID 11240433.
  16. ↑ JOSEPH RB, FRAZER JP (1964). "OTOSCLEROSIS INCIDENCE IN CAUCASIANS AND JAPANESE". Arch Otolaryngol. 80: 256–62. doi:10.1001/archotol.1964.00750040266004. PMID 14172803.
  17. ↑ Gristwood RE, Venables WN (1983). "Pregnancy and otosclerosis". Clin Otolaryngol Allied Sci. 8 (3): 205–10. doi:10.1111/j.1365-2273.1983.tb01428.x. PMID 6883784.
  18. ↑ Niedermeyer HP, Arnold W (2008). "Otosclerosis and measles virus - association or causation?". ORL J Otorhinolaryngol Relat Spec. 70 (1): 63–9, discussion 69-70. doi:10.1159/000111049. PMID 18235207.
  19. ↑ Crompton M, Cadge BA, Ziff JL, Mowat AJ, Nash R, Lavy JA; et al. (2019). "The Epidemiology of Otosclerosis in a British Cohort". Otol Neurotol. 40 (1): 22–30. doi:10.1097/MAO.0000000000002047. PMC 6314447. PMID 30540696.
  20. ↑ Fitzgerald DC (1985). "The aging ear". Am Fam Physician. 31 (2): 225–32. PMID 3883726.
  21. ↑ Declau F, Spaendonck MV, Timmermans JP, Michaels L, Liang J, Qiu JP; et al. (2007). "Prevalence of histologic otosclerosis: an unbiased temporal bone study in Caucasians". Adv Otorhinolaryngol. 65: 6–16. doi:10.1159/000098663. PMID 17245017.
  22. ↑ Tato JM, Tato JM (1967). "Otosclerosis and races". Ann Otol Rhinol Laryngol. 76 (5): 1018–25. doi:10.1177/000348946707600512. PMID 6074235.
  23. ↑ Imauchi Y, Lainé P, Sterkers O, Ferrary E, Bozorg Grayeli A (2004). "Effect of 17 beta-estradiol on diastrophic dysplasia sulfate transporter activity in otosclerotic bone cell cultures and SaOS-2 cells". Acta Otolaryngol. 124 (8): 890–5. doi:10.1080/00016480310017081. PMID 15513522.
  24. ↑ Thomas JP, Minovi A, Dazert S (2011). "Current aspects of etiology, diagnosis and therapy of otosclerosis". Otolaryngol Pol. 65 (3): 162–70. doi:10.1016/S0030-6657(11)70670-9. PMID 21916215.
  25. ↑ 25.0 25.1 Ealy M, Smith RJH (2011). "Otosclerosis". Adv Otorhinolaryngol. 70: 122–129. doi:10.1159/000322488. PMID 21358194.
  26. ↑ Sellari-Franceschini S, Ravecca F, De Vito A, Berrettini S (1998). "[Progressive sensorineural hearing loss in cochlear otosclerosis]". Acta Otorhinolaryngol Ital. 18 (4 Suppl 59): 59–65. PMID 10205935.
  27. ↑ 27.0 27.1 Bagai A, Thavendiranathan P, Detsky AS (2006). "Does this patient have hearing impairment?". JAMA. 295 (4): 416–28. doi:10.1001/jama.295.4.416. PMID 16434632. Review in: Evid Based Nurs. 2006 Oct;9(4):120 Review in: Evid Based Med. 2006 Aug;11(4):116
  28. ↑ 28.0 28.1 Virk JS, Singh A, Lingam RK (2013). "The role of imaging in the diagnosis and management of otosclerosis". Otol Neurotol. 34 (7): e55–60. doi:10.1097/MAO.0b013e318298ac96. PMID 23921926.
  29. ↑ 29.0 29.1 Wegner I, van Waes AM, Bittermann AJ, Buitinck SH, Dekker CF, Kurk SA; et al. (2016). "A Systematic Review of the Diagnostic Value of CT Imaging in Diagnosing Otosclerosis". Otol Neurotol. 37 (1): 9–15. doi:10.1097/MAO.0000000000000924. PMID 26649602.
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