Otospongiosis is inherited as : [AIPGMEE – 1995]
1) Autosomal dominant
2) Autosomal recessive
3) X-linked dominant
4) X-linked recessive
Otosclerosis or otospongiosis is a bony labyrinthine disease where lamellar bone is replaced by immature spongy bone of more cellularity and vascularity. The change occurs mainly in the endochondral layer of ottic capsule. m/c site is just anterior to oval fenestra.
Autosomal dominant inheritance. More common in whites and Indians. more common in women
Blue mantles – Both osteoblastic and osteoclastic activities take place in the otosclerotic process that starts along the blood vessels as finger-like invasion. Bluish appearance on H&E staining earned them the name “blue mantles of Manasse”.
Paracusis Willisii – pt. hears better in noisy environment
Schwartz sign: Flamingo pink discolouration of TM due to vascularisation of promontory. (only in 2-10% cases) Surgery is contraindicated in patients with positive Schwartz sign. It is an indication for sodium fluoride therapy.
Clinic: Slowly progressive, bilateral, CHL in a female, aggravated by pregnancy. Vertigo, tinnitus and SNHL may be present in patients with cochlear otosclerosis.