The role of dexamethasone to preventing cochleotoxicity caused by intratympanic gentamicin application

VIII. NG L ZCE ÖZET?THE ROLE OF DEXAMETHASONE TO PREVENT NGCOCHLEOTOXICITY CAUSED BY INTRATYMPANIC GENTAMICINAPPLICATION?Intratympanic gentamicin treatment is a wide spread choice ofmanagement for intractable Meniere disease. This treatment modality hasmany advantages, but because of its cochleotoxicity aside from its aimedvestibulotoxicity, limits its usage.The potential efficacy of dexamethasone to preventing cochleotoxicitycaused by intratympanic gentamicin treatment in guinea pigs was evaluatedexperimentally in our study.Total of 22 guinea pigs were divided into 7 groups, each of which adifferent medication was applied. There were 2 guinea pigs in the groups ofno application, multi-dose saline and neomycin application; 4 guinea pigs inthe groups of single and multi-dose sole gentamicin groups and single andmulti-dose gentamicin + dexamethasone combination groups. The medicalagents that were applied were selected among commonly prescribed formswhen dexamethasone was acquired as active compound and prepared in theconcentration of 24 mg/ml.The sampled histological specimens were evaluated via rutine lightmicroscopically, immunohistochemically and transmission electronmicroscopically. The cellular edema, increase in acidophilia, piknosis of thenucleus, increase in density of the cytoplasma, cytoplasmic vacuoles andlipid quantity, changes in axone and myelin, infiltration of polymorphonuclearlymphocyte were compared histopathologically. Apoptotic cell quantity wascounted in each group and the values were compared among the groups.It is demonstrated that combination of intratympanic gentamicin withdexamethasone has been effective in preventing cohleotoxicity in both singleand multi-dose applications. It has been shown that there was a statisticallysignificant decrease in the number of apoptotic cells with supplementarydexamethasone combined with the multi-dose intratympanic gentamicinapplication.