Otosclerosis is a progressive bone remodeling disease that effects the otic capsule of the temporal bone. The stapes becomes anchored to the anterior wall of the oval window and the ossicles join together into an immovable mass. Although this disease originates in the bony labyrinth of the inner ear, it is considered a conductive hearing loss because it effects the middle ear. Otosclerosis is found bilaterally in 80% of patients; however, otosclerosis is unilateral in the earlier stages of the disease. Otosclerosis occurs primarily more among women than men and age of onset can vary from 16 to 30 years of age. Otosclerosis is also more prevalent in Caucasians and lower in blacks, Asians, and Native Americans.
Hearing loss, vertigo and tinnitus are the main symptoms of otosclerosis. In the early stages there is a decrease in hearing sensitivity in low-frequency tones due to stiffness on impedance. Patients often report difficulty hearing male voices or vowel sounds in words. As the disease progresses, hearing loss becomes greater due to the stapes becoming completely fixated. This causes sensitivity in both high and low frequencies, flattening the audiogram. …show more content…
They found that the otic capsule comprises an outer layer of periosteal connective tissue which contains the external bony layer. The middle bony layer is separated from the external bony layer by a thin stratum of almost featureless bone. The inner surface is separated from the cochlea by a narrow endosteal layer. A main feature of the development of the otic capsule is a large number of canals formed in the external and middle layers. In the external layer these are mainly Volkmann’s canal type, which run in all directions. They concluded that the main plaque of otosclerosis is a histologic replica of the external layer and seems to arise from similar cells in the periosteum (Michaels & Soucek,
Hearing loss, vertigo and tinnitus are the main symptoms of otosclerosis. In the early stages there is a decrease in hearing sensitivity in low-frequency tones due to stiffness on impedance. Patients often report difficulty hearing male voices or vowel sounds in words. As the disease progresses, hearing loss becomes greater due to the stapes becoming completely fixated. This causes sensitivity in both high and low frequencies, flattening the audiogram. …show more content…
They found that the otic capsule comprises an outer layer of periosteal connective tissue which contains the external bony layer. The middle bony layer is separated from the external bony layer by a thin stratum of almost featureless bone. The inner surface is separated from the cochlea by a narrow endosteal layer. A main feature of the development of the otic capsule is a large number of canals formed in the external and middle layers. In the external layer these are mainly Volkmann’s canal type, which run in all directions. They concluded that the main plaque of otosclerosis is a histologic replica of the external layer and seems to arise from similar cells in the periosteum (Michaels & Soucek,