2,3) Sensorineural hearing loss is caused by the hyalinization of the spiral ligament adjacent to the otosclerotic focus, which affects the otic capsule in such a way that it interferes with the function of the organ of Corti.
Cochlear otosclerosis: Statistical analysis of relationship of spiral ligament hyalinization to hearing loss.
This damage ranges from relatively minor displacement of the basilar membrane to severe fracture of the osseous spiral lamina, tearing of the basilar membrane or spiral ligament, and deviation of the electrode path from its intended location in the ST to the overlying scala media and/or scala vestibuli.
Conversely, if the straightened electrode and stylet are inserted too far beyond the cochleostomy, the electrode tip will contact the outer wall of the first cochlear turn, possibly resulting in damage to the spiral ligament or upward penetration into the scala vestibuli.
16) Persistent tinnitus despite stapedotomy and an air-bone gap within 15 dB, which occurred in the 1 patient in our study who did not improve, is probably caused by an underlying condition, such as glucose intolerance, excessive caffeine intake, destruction of Corti hair cells by proteolytic enzymes released from otosclerotic foci, or an inadequate supply of blood to the inner ear secondary to hyalinization of the spiral ligament
of the stria vascularis ductus cochlearis, which is a natural consequence of the progression of otospongiotic disease.