Die Behandlung der akuten Innenohrschwerhörigkeit — Ergebnisse tierexperimenteller Untersuchungen

Summary

Up to the present time, treatment of acute labyrinthine deafness, particularly of sudden deafness, has represented a considerable therapeutic problem. In the present study, the attempt was made to examine the therapeutic effects of various treatment methods on the previously damaged internal ear by means of comparative animal experiments. The experimental animals used were guinea pigs in which an acute hearing defect had been induced by exposure to noise or by cryodamage. The following medications or therapeutic procedures were examined: 1. pentoxifyllin (Trental), 2. naftidrofuryl (Dusodril), 3. low-molecular dextran (Rheomacrodex), 4. cervical sympathectomy. Controls of the auditory threshold were done for 16 days by derivation of the compound action potentials (CAP). This revealed in part significant differences in the extent of hearing-recovery — related to the SAP amplitude or the auditory threshold — compared with the untreated control group. Thus, improvement of the auditory threshold after cryodamage was, for example, significantly greater under treatment with low-molecular dextran than in the control group. In the subsequent histological examination, the result of the electrophysiological was compared with the hair-cell finding. This comparison showed that, in more than 90% of the animals, a good correlation could be made between the hair-cell lesion and the respective hearing loss.