XXXIX Correlation of Sensorineural Hearing Impairment and Otosclerosis

There has been some question as to whether otosclerosis causes sensorineural hearing loss.1,2 However, as evidence accumulates it appears that there is a definite relationship.3-11 Various theories have been proposed to explain the loss. Siebenrnann'' and Wittmaach suggested a toxic secretion by the otosclerosis involving the endosteum; this in turn was suspected to affect the neural elements in the inner ear. Ruedr'! has suggested a vascular cause of the hearing loss that may occur in two forms, one being due to venous stasis in the otosclerotic focus in proximity to the spiral ligament and the second due to impairment or even thrombosis of the vessels in the internal auditory canal. The findings to be presented tend to substantiate both of Riiedi's theories.