Experimental Study on Auditory Disturbance due to Endotoxin

Part 2: Effect of Topical Administration

Abstract

A small percentage of patients with secretory otitis media also have perceptive deafness. Endotoxins existing in the fluid retained in the middle ear are noted as a causative substance of perceptive deafness. Endotoxin was administered to the middle ear cavity and auditory brainstem response (ABR) was determined. At the same time, the effect of the endotoxin on the auditory system was examined. In the group receiving 0.2 ml/kg of endotoxin (1 mg/ml), no significant change in the latency was observed in any of the ABR waves. In the group receiving 0.2 ml/kg of endotoxin (5 mg/ml), no significant change was observed in wave I three days after administration. However, a significant prolongation in the latency was seen in the waves II, M and IV. As for the interpeak latency, a significant prolongation was observed in the I-II interpeak latency. When endotoxin was administered at high concentrations, such as 50 and 100 mg/ml, there were cases in which ABR was not present.