抄録
One hundred and eight ears with cholesteatoma were studied from clinical and Impedance audiometric viewpoints.
Those ears showed relatively large air-bone gaps on the pure-tone audiogram (mean 43.1 dB). Impedance audiometric data were available on 41 ears with attic perforation and without perforation of eardrum. Tympanograms in this group were typically type B (71%). Type C were observed in 19% and type A in 10%. The median static compliance was 0.15 cc, with the 10th and 90th percentiles at 0.03cc and 0.52cc, respectively. The stapedial reflex could not be elicited 84% of the time.
Here we typically observed the impedance pattern associated with a substantial increase in the mass of the vibratory system-a type B tympanogram and a very low static compliance.
Air-bone gap is small in the cases with type A tympanogram and normal static compliance, and in those cases, cholesteatoma were liable to be restricted in attic. With the exception of the instance cited above, the impedance audiometry did not always lead to correct assessment of ossicular lesion or expansion of cholesteatoma.
