title: Olivocochlear efferent reflex strength in vestibular schwannoma patients.
abstract: OBJECTIVE
  The olivocochlear reflex strength can be measured using contralateral acoustic stimulation (CAS) of transient evoked otoacoustic emissions (TEAOEs). The efferent suppression (ES) thus reflects the functional intactness of the efferent auditory system. In patients with unilateral vestibular schwannoma (VS), the results of ES are unclear.
  
  
  METHODS
  This cross-sectional study evaluated click and noise intensity conditions for measuring ES using CAS of TEOAEs in nine patients with unilateral VS and in gender-, age- and ear side-matched control subjects.
  
  
  RESULTS
  Two optimal click and noise intensity level combinations were identified. This pilot study compared the amount of ES between tumour and non-tumour ears versus control ears in patients with unilateral VS, but there were no statistically significant differences.
  
  
  CONCLUSIONS
  Future studies should include a larger population of unilateral VS patients with different grades of hearing loss.
authors.forename: H
authors.initials: H
authors.lastname: Keppler
authors.forename: F
authors.initials: F
authors.lastname: Van Reybrouck
authors.forename: I
authors.initials: I
authors.lastname: Dhooge
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D003051:Cochlea / Q000503:physiopathology*; D004525:Efferent Pathways / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000503:physiopathology*; D017084:Otoacoustic Emissions, Spontaneous; D012022:Reflex, Acoustic / Q000502:physiology*