title: Investigation of the cochlear effects of intratympanic steroids administered following acoustic trauma.
abstract: OBJECTIVE
  To electrophysiologically and histomorphologically demonstrate the effects of intratympanic corticosteroids administered following an acoustic trauma on cochlear hair cells.
  
  
  METHODS
  The trial was performed on 16 Wistar albino rats. The rats underwent distortion product otoacoustic emissions (DPOAE) measurement before the acoustic trauma, and subsequently rats were exposed to noise. Following acoustic trauma, the otoacoustic emission measurement was repeated. The rats were divided into two groups, a study group and a control group. The study rats were injected with methylprednisolone via the intratympanic route throughout the study. In the control group, the rats were injected daily with saline. After performing repeated otoacoustic emission measurements, one rat in each of the groups was sacrificed and their cochleae isolated.
  
  
  RESULTS
  The histological investigation performed after the 1st week revealed a statistically significantly higher rate of apoptotic cells in the inner and particularly the outer hair cells of the rat cochleae in the control group compared to the study group. Early measurement of DPOAE within the 1st week demonstrated significantly better amplitudes in the study group compared to controls. The otoacoustic emission assessment performed on the 14th day demonstrated statistically similar DPOAE values between the two groups.
  
  
  CONCLUSIONS
  Intratympanic methylprednisolone injection administered following an acoustic trauma appears to reduce cochlear outer hair cell loss. The impact on hearing loss is less certain. Early measurement of DPOAE within the 1st week shows significantly better amplitudes in the study group compared to controls. However at 2 weeks, there is no statistically significant difference in DPOAE amplitudes between the study and control group.
authors.affiliation: ENT Clinic, Silvan Dr Yusuf Azizoglu State Hospital, Diyarbakir, Turkey. ozdogan.fatih@gmail.com
authors.forename: Fatih
authors.initials: F
authors.lastname: Ozdogan
authors.forename: Serdar
authors.initials: S
authors.lastname: Ensari
authors.forename: Ozgur
authors.initials: O
authors.lastname: Cakir
authors.forename: Kursat Murat
authors.initials: KM
authors.lastname: Ozcan
authors.forename: Sabri
authors.initials: S
authors.lastname: Koseoglu
authors.forename: Talih
authors.initials: T
authors.lastname: Ozdas
authors.forename: Seren Gulsen
authors.initials: SG
authors.lastname: Gurgen
authors.forename: Huseyin
authors.initials: H
authors.lastname: Dere
mesh_terms: D000818:Animals; D003051:Cochlea / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage*; D006317:Hearing Loss, Noise-Induced / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D007267:Injections; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D014432:Tympanic Membrane
chemical_list: D005938:Glucocorticoids