DPOAEs and vestibular function in different types of autosomal-dominant non-syndromal hearing impairment

Abstract

Background/ objective: The application of distortion-product otoacoustic emissions (DPOAE) could be advantageous in the early diagnostic of descendants of families with autosomal-dominant non-syndromal hearing impairment (ADNSHI). Patients/ methods: DP-grams of 58 affected persons of 21 families with ADNSHI were measured ( f 2/ f 1=1.22; L 1=70 dB SPL; L 2=65 dB SPL; four points per octave). The mode of transmission was determined by pedigree. The phenotype was determined by pure tone audiometry (PTA) and caloric vestibular test (CVT). Results: We could find 12 families with mild to severe mid-frequency U-shaped ADNSHI, three families with steeply sloping high tone ADNSHI, two families with moderate to severe gently sloping high tone ADNSHI, three families with profound ADNSHI and one family with variable ADNSHI. One family showed an additional vestibular lesion. Fifty-six of 58 affected persons showed pathological DP-grams. In 48 persons (83%) these DP-grams showed distinct similarity within the families, that they could be classified as ‘ADNSHI-typical’ within an affected family. Conclusions: Affected persons of a family with ADNSHI show similar DP-grams. These DP-grams are useful in the early routine-diagnostics of newborns within such families.