COCHLEAR VASCULAR PATHOLOGY AND HYDROPS IN OTOSCLEROSIS

Three ears with otosclerosis were found incidentally in a series of hu man temporal bones examined to evaluate cochlear sensorineural degener ation. Otoslerosis was identified with microdissection, surface prepar ation technique and transmission electron microscopy. Vascular abnorma lities were present in all ears, and otosclerosis involved the cochlea r endosteum extensively, mainly in the scala tympani of the basal turn . In the scala tympani of the lower half of the basal turn, shunts had formed so that venules deviated abruptly from their normal radiating course towards the spiral vein, left the scala and entered into otoscl erotic foci. There was a marked loss of radiating venules in areas whe re otosclerosis affected the endosteum of the scala. In the pair of bo nes capillaries in the stria vascularis were extremely dilated, the wi dest being 80 mu m in diameter. The third single bone from a patient w ith Meniere's disease had severe cochleo-saccular hydrops. Ten seriall y sectioned temporal bones with known otosclerosis were reviewed. Two of the bones, one of which had cochleo-saccular hydrops, displayed vas cular shunts in the scala tympani and enormously dilated strial capill aries with a maximum diameter of 139 mu m.