title: Contralateral suppression of otoacoustic emission in patients with tinnitus.
abstract: BACKGROUND
  The medial olivocochlear bundle effect is studied through the suppression of otoacoustic emissions and seems to be influenced by the laterality of the central nervous system, presenting no symmetry between right and left ear. A dysfunction of this bundle may be involved in the generation of tinnitus, although this fact was not confirmed.
  
  
  OBJECTIVE
  Study the suppression of distortion product otoacoustic emissions in tinnitus patients.
  
  
  METHODS
  A case-controlled study involving 44 tinnitus patients from the Tinnitus Group of the ENT Department of the University of São Paulo Medical School and 44 controls who underwent distortion product otoacoustic emissions testing with and without contralateral noise. Only the results from the right ears from both groups were compared.
  
  
  RESULTS
  There was a relationship between the presence of tinnitus and the absence of suppression at all frequencies studied (OR>2.1).
  
  
  CONCLUSIONS
  There was a correlation between diminished effectiveness of the medial olivocochlear bundle and the presence of tinnitus.
authors.affiliation: DERDIC, PUCSP, Brazil. lopessquare@ig.com.br
authors.forename: Mariana Lopes
authors.initials: ML
authors.lastname: Fávero
authors.forename: Tanit Ganz
authors.initials: TG
authors.lastname: Sanchez
authors.forename: Ricardo Ferreira
authors.initials: RF
authors.lastname: Bento
authors.forename: Andreia Ferreira
authors.initials: AF
authors.lastname: Nascimento
mesh_terms: D000161:Acoustic Stimulation; D001299:Audiometry; D016022:Case-Control Studies; D003051:Cochlea / Q000294:innervation* / Q000503:physiopathology; D004525:Efferent Pathways / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D014012:Tinnitus / Q000503:physiopathology*