Focus and Pathogenesis of Sudden Deafness

Abstract

As the anionic angiographic contrast medium (76% Urografin^®) showed excellent therapeutic effect on sudden deafness, the focus of the disease is speculated to be located at the endothelium in the stria vascularis. By electron microscopic study of the vascular endothelium with kationized poly-1-lysine gold colloid, anionic sites were observed on the luminal surface with sialic acid and basilar membrane with hyaluronic acid. By electrophysiological study of the stria vascularis, positive charge of 20mV in the basal cell, 50mV in the intermediate cell, 90mV in the margnal cell, and 100mV of EP were observed respectively. Therefore, it is concluded that the blood cochlear barrier is an ionic charge barrier between the endothelium and the strial cells.
If the negative charge on the luminal surface of the endothelium is lost by unknown etiology, the barrier is broken down and EP decreases causing sudden deafness. In this condition the luminal surface is charged positive when the strial cells keep their active transport function. Thus, contrast medium bonds ionic on the luminal surface making pseudo-barrier, which acts as a promoter for recovey from the deafness. In conclusion, sudden deafness should be a barrier break deafness due to dysfunction of glycoprotein metabolism of the vascular endothelium in the stria vascularis.