Audiological Characteristics of Conductive Deafness with Intact Tympanic Membrane
LI Mengqin
LU Zhaoyi
SONG Weiming
XIN Ying
PAN Tao
Abstract：Objective To report audiological characteristics of conductive deafness with intact tympanic membrane for predicting intraoperative findings before operation.Methods Data from 34 patients with conductive deafness and intact tympanic membranes seen at the Department of Otolaryngology,Peking University Third Hospital,from November 2012 to November 2023 were retrospectively analyzed.The cases were grouped based on ossicular chain lesions,i.e.,ossicular chain interruption and stapedial footplate fixation,and based on.the type of disease,i.e.,otosclerosis and ossicular chain malformation.Pre-and postoperative pure tone audiometry(PTA)and air-bone gap(ABG)at each frequency,as well as intraoperative findings,were analyzed.Results Intraoperative findings confirmed otosclerosis(n=14),ossicular chain malformation(n=16)and ossicular chain interruption due to other causes(n=4).Postoperative PTA,ABG and air conduction thresholds improved across multiple frequencies compared to before operation(P<0.05).Bone conduction thresholds at 500 Hz and 1000 Hz in cases with stapedial footplate fixation were higher than those with ossicular chain interruption(P<0.05),with greater ABG in the latter than in the former(P<0.05)except at 250 Hz(P>0.05).Hearing thresholds elevation at 500 Hz in cases with osticular chain malformation was greater than in those with otosclerosis,with better bone conduction thresholds at 500,1000,2000,4000 and 8000 Hz(P<0.05).Conclusion Conductive deafness with intact tympanic membrane involves various etiologies and ossicular chain abnormalities,with each showing corresponding audiological characteristics.In continuous ossicular chain with stapedial fixation,bone conduction loss is prominent at 500 Hz and 1000 Hz,with loss at 1000 Hz being characteristic for otosclerosis,although not unique to otosclerosis.Ossicular chain fixation often features large ABG over the low frequency region and small ABG in the middle and high frequency regions.Ossicular chain disruption demonstrate large ABG across all frequencies.Intraoperative ossicular chain findings often can be predicted with certain reliability based on preoperative audiological characteristics.
Keywords：intact tympanic membraneconductive deafnessaudiological characteristicsotosclerosismalformation of ossicular chain
Publication Date：2025-06-15
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 353-358 )