Otosclerosis occurs with excessive remodelling of the otic capsule and ossicles, leading to fixation of the stapes within the oval window and thus a conductive hearing loss. Approximately 50% have an autosomal dominant genetic condition with otosclerosis and some have an infective link (through Measles vaccine and IgG). It most commonly occurs in Caucasian females between the ages of 20 to 40, and there is a strong association with hormonal change, with hearing often declining during puberty or pregnancy.
Clinical features include gradual hearing loss, tinnitus, and rarely vertigo. The hearing loss is usually bilateral, though can start unilateral, and preferentially affects lower frequencies; this has the paradoxical effect of better hearing in noisier surroundings/background noise. Otoscopy would appear normal or demonstrate a positive Schwartze’s sign [red vascular blush over the promontory and oval window]. Patients are generally offered non-operative management in the form of hearing aids initially but may later require stapes surgery.