Surgical and Audiological Outcomes of Endoscopic Stapes Surgery

Otosclerosis is a pathological bone remodeling process that affects the middle and inner ears. It was first reported by Antonio Maria Valsalva in 1735 and subsequently described pathologically by Adam Politzer in 1839 . In otosclerosis, the normal, dense endochondral bone of the otic capsule around the inner ear labyrinth is replaced by irregularly laid spongy bone, which subsequently hardens and leads to fixation of the stapes footplate . Otosclerosis causes progressive conductive hearing loss that typically presents with a normal tympanic membrane. However, a reddish shadow on the promontory of the cochlea may be seen in some cases (Schwartze sign) if the tympanic membrane is clear enough. Initial symptoms of otosclerosis include decreased sensitivity to low-frequency sounds, such as whispers. Patients may also paradoxically deny difficulty hearing conversation in loud background noise, which is termed "paracusis Willisii" or "paracusis of Willis,. Tinnitus may worsen as the disease progresses. Vertigo is usually mild, but as the disease progresses, balance may deteriorate, mimicking Ménière disease. . On physical examination, patients with otosclerosis may speak in low volume and monotonous voices. Otoscopy may reveal no abnormalities at all. With active otosclerosis, however, increased vascularity of the cochlear promontory may be visible through the tympanic membrane A Weber test performed with a 512 Hz (Hertz) fork will generally lateralize toward the ear with the conductive loss or toward the ear with the greater conductive loss in cases of bilateral otosclerosis . In most cases of otosclerosis, pure tone audiometry shows low frequency decreases in air conduction thresholds. Bone conduction, however, typically remains normal. A "Carhart notch" is often seen, which is an artifactual dip in the bone conduction line by 20-30 dB(disciple) at 2,000 Hz due to the resonance frequency of the ossicular chain . There is no medical therapy that is curative for otosc