What is otosclerosis?
Otosclerosis also called otospongiosis denotes abnormal hardening and remodeling of structures in the ear. ‘Oto’ means pertaining to the ear & ‘sclerosis’ means abnormal hardening of tissues. In the inner ear lies a bony structure called the ‘otic capsule’. In this condition, the endochondral layer of this bony otic capsule of the labyrinth in the ear gets substituted by spongy irregularly laid bone causing various clinical manifestations.
How does one get Otosclerosis?
Usually starting in the 20s & 30s, the exact cause of acquiring this condition is unknown, however, hereditary association with a positive familial history has been proven now. Genetic loci such as 6p, 9p with genetic association with COL1A1 gene and many more are not being isolated as close associations and etiologies of otosclerosis. Women are more likely to be affected by the disease and association with pregnancy has now proven to be controversial.1 Other associated factors that seem to be linked to appearance or worsening of the disease include trauma and viral infections
What happens to my ear in Otosclerosis?
Repeated bone resorption and bone deposition cycles create a cascade of bone remodeling where the normal bone gets replaced to a more spongy or scarred bone. As the bone changes in stages from spongy bone loss to scared sclerosed bone, the bone starts to grow over the ossicles i.e. stapes and over the inner ear complex thereby giving rise to symptoms.
What are the symptoms of otosclerosis?
The disease begins in one and progresses to involve the other ear and hence, usually there are symptoms noted in both ears on presentation.
1. Hearing disturbances- initially patient has low frequency hearing loss (whispering) and can also classically report being able to hear better when its noisy (Paracusis Willisii)
2. Vertigo/ giddiness
3. Tinnitus i.e., high pitched sound in the ear
How do we evaluate and diagnose this disease?
On clinical examination, otosclerosis patients classically show a normal tympanic membrane with about 10% ear drums showing ‘Schwartz sign’ where due to active disease, the promontory has a classical vascular appearance. 2
On hearing testing, PTA shows low frequency hearing loss with bone conduction troughs at 20-30dB that’s most significant at 2000Hz called the Carhart’s notch.
severe cases may also show flat tympanometry curves indicating poor ossicle compliance and restricted mobility of these bones.
PTA showing classical Carhart’s notch in the left ear Bone conduction graph
CT scan Temporal bone identifies changes that are predominantly anterior to the oval window. classical signs of the bony disease with thickening of the round window and stapes footplate can be visualized.
How is this otosclerosis treated?
Medical management of otosclerosis is purely restricted to halting the disease progression and there is no medical treatment for getting rid of otosclerosis. Drugs such as Sodium Fluoride and Bisphosphonates have been used with promising yet controversial results. 3,4
Bilateral Hearing aids have been used in patients as an isolated management method or as an adjunct.
Surgery such as Stapedotomy or Stapedectomy is the mainstay of treatment along with the placement of the prosthesis.
The surgery is a routine daycare procedure and helps the conduction be restored thereby reversing the findings that we see in investigations such as Carhart’s notch.
It can be done both by a basic incision behind the ear canal and by accessing these regions through a microscope or by an endoscope where there are no incisions made over the ear. Treatment of sensorineural hearing loss in otosclerosis. Otol Neurotol. 2012 Oct;33(8):1308-14.
Microscopic view of the middle ear showing Stapedotomy
Microscopic view of the middle ear showing Stapes prosthesis in place
What happens if I leave my otosclerosis untreated?
Although gradually progressive, otosclerosis causes a significant degree of hearing loss that can correlate to poor quality of life. As the patients are in their 20s and 30s on diagnosis, the significant hearing loss is socially impairing and debilitating with increased accident proneness and other psychological associations of being nearly deaf at a young age. The significant morbidity of this condition can be easily managed by surgical treatment.
Hearing problems in these patients worsen during pregnancy and hence pregnancy is considered an accelerating as well as triggering association with otosclerosis and requires workup and counseling accordingly.
As there is a familial association, screening investigative workup of family members is recommended.
What are the complications of stapes surgery?
1. Facial nerve paresis/injury
2. Taste disturbances
3. Tinnitus & giddiness (in cases with severe hearing loss and advanced disease at diagnosis)
At Bangalore ENT Institute & Research Center, Our expert doctors offer comprehensive otosclerosis treatment and the necessary post-treatment follow-ups to help you get back to normal! To know more about otosclerosis, talk to our doctors at firstname.lastname@example.org or on any of our social handles!
1 . Gristwood RE, Venables WN. Pregnancy and otosclerosis. Clin Otolaryngol Allied Sci. 1983 Jun;8(3):205-10.
2. Salomone R, Riskalla PE, Vicente Ade O, Boccalini MC, Chaves AG, Lopes R, Felin Filho GB. Pediatric otosclerosis: case report and literature review. Braz J Otorhinolaryngol. 2008 Mar-Apr;74(2):303-6.
3. Hentschel MA, Huizinga P, van der Velden DL, Wegner I, Bittermann AJ, van der Heijden GJ, Grolman W. Limited evidence for the effect of sodium fluoride on the deterioration of hearing loss in patients with otosclerosis: a systematic review of the literature. Otol Neurotol. 2014 Jul;35(6):1052-7.
4. Quesnel AM, Seton M, Merchant SN, Halpin C, McKenna MJ. Third-generation bisphosphonates for