Experimental study in guinea pigs to evaluate the impact of the aeration status of the middle ear over the response on the otoacoustic emission test

• Grant number: 06/01059-5
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2006
• End date: May 31, 2007
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Ney Penteado de Castro Júnior
• Grantee: Ney Penteado de Castro Júnior
• Host Institution: Faculdade de Ciências Médicas da Santa Casa de São Paulo (FCMSCSP). Fundação Arnaldo Vieira de Carvalho. São Paulo , SP, Brazil

Abstract

The association of otoacoustic emissions with brainstein evoked acoustic potencials and the clinical exam has been considered the best screening method to detect auditive deficiency. Neverthless, the universality of the exam has been questioned due to problems related to the interference that may occur when there is liquid in the tympanic cavity. As is very well known the high prevalence of efusion in children between 2 and 6 years-old, as well as the real possibility of it occur also in neonates, the knowledge of wich is the actual interference could help in the evaluation of the results of the OAE. So far, the investigation has focussed on the study of clinical data of patients with middle ear efusion submmited to OAE. There isn't studies about the relationship pf the fluid quantity and viscosity with the result of OAE. Aim: To establish the relationship between the presence and quality of liquid in the middle ear and the response of the OAE transient, expontaneous and transitory, in guinea pigs. Material and Method: 53 guinea pigs, of about 400g and3 months old will be studied. The will be submmited to tympanotomy and receive a certain amount of liquid in three different volume and density. They will be grouped according to the liquid received. The OAE will be acomplished before and after the injection. The contralateral ear will be the pre and post control. After the second exam all animals will be sacrificed to middle ear histologic exam. The results will be compared statistically. (AU)