Brazilian Society of Otology task force - Otosclerosis: evaluation and treatment

Abstract

Objectives: To review and provide evidence-based recommendations for the diagnosis and treatment of otosclerosis.

Methods: Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on otosclerosis were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

Results: The topics were divided into 2 parts: 1) Diagnosis - audiologic and radiologic; 2) Treatment - hearing AIDS, pharmacological therapy, stapes surgery, and implantable devices - bone-anchored devices, active middle ear implants, and Cochlear Implants (CI).

Conclusions: The pathophysiology of otosclerosis has not yet been fully elucidated, but environmental factors and unidentified genes are likely to play a significant role in it. Women with otosclerosis are not at increased risk of worsening clinical condition due to the use of contraceptives or during pregnancy. Drug treatment has shown little benefit. If the patient does not want to undergo stapedotomy, the use of hearing aids is well indicated. Implantable systems should be indicated only in rare cases, and the CI should be indicated in cases of profound deafness.

Keywords: Hearing loss, conductive; Hearing loss, mixed conductive-sensorineural; Otosclerosis; Stapes surgery.

Figure 1

Axial section of temporal bones of patients with different stages of otosclerosis. (A) Fenestral otosclerosis. (B) Cochlear otosclerosis.; O, Otosclerotic focus on the ante fenestram fissula; V, Vestibule; (*), Reissner’s membrane distention compatible with endolymphatic hydrops; Arrowhead, Otosclerotic focus involving the cochlea.

Figure 2

Conductive hearing loss in the left ear. Early stage of otosclerosis.

Figure 3

Conductive hearing loss with bilateral Carhart notch.

Figure 4

Bilateral mixed hearing loss, with bilateral Carhart notch.

Figure 5

Fenestral otosclerosis. Black continuous arrow ‒ fissula ante fenestram ‒ hypodense foci of bone. Black discontinuous arrow – oval window. White arrow – stapes.

Figure 6

(A) Arrow indicates otospongiosis in the area of the oval window. (B) Double ring/halo sign around the cochlea showing otospongiotic stage with probable sensorineural hearing loss.

Figure 7

Area of demineralization of the internal auditory canal.

Figure 8

(A) Thickness in the area of the oval window is 1.64 mm (normal). (B) Thickness of 3.32 mm compatible with otosclerosis.

Figure 9

Footplate involvement by hypodense foci bone.

Figure 10

Arrow indicates otospongiosis in the area of the round window.

Figure 11

Superior semicircular canal dehiscence.

Figure 12

Arrow indicates malformed ossicular chain with fixation of the malleus head and incus body.

Figure 13

Enlargement of vestibular aqueduct (black arrows). (A) Right ear. Axial scan. Temporal bone high-resolution computed tomography. (B) MRI ‒ T2-weighted sequence of the same patient.

Figure 14

(A) Advanced otosclerosis with double ring/halo sign. (B) MRI ‒ T2-weighted sequence of the same patient showing stenosis of the scala tympani in the basal turn. BT, Basal Turn; SV, Scala Vestibuli; PCSC, Posterior Semicircular Canal.

Figure 15

(A) MRI ‒ T2-weighted sequence A. Normal. (B) Advanced otosclerosis with showing stenosis of the scala tympani in the basal turn. BT, Basal Turn; SV, Scala Vestibuli; ST, Scala Tympani; PCSC, Posterior Semicircular Canal.

Figure 16

(A) Obliteration of the round window and part of basal turn.A ‒ Temporal bone high-resolution computed tomography; (B) MRI ‒ T2-weighted sequence.