M. Vonunge et D. Baggersjoback, TYMPANIC MEMBRANE-CHANGES IN EXPERIMENTAL OTITIS-MEDIA WITH EFFUSION, The American journal of otology, 15(5), 1994, pp. 663-669
A tympanometric in vitro model was used to measure the mechanoacoustic
properties of the tympanic membrane. Impedance measurements were made
during the early course (1-21 days) of experimentally induced otitis
media with serous effusion in the Mongolian gerbil. A more severe form
of otitis media with mucoid effusion was produced by electrocauteriza
tion of the nasopharyngeal orifice of the eustachian tube. The dynamic
peak values of the acoustic susceptance were significantly reduced ea
rly in the course of serous otitis media, indicating increased stiffne
ss of the tympanic membrane. In mucoid otitis media, the same reaction
of the tympanic membrane was predominant, but the reverse reaction al
so was recorded in a few ears. These results indicate that alterations
of the mechanoacoustic stiffness of the tympanic membrane occur durin
g otitis media with effusion. Such changes may play an important role
in the further course of the disease. The clinical implications of the
tympanic membrane stiffness changes are discussed. Significant histop
athologic changes were encountered in all cell layers, whereas the col
lagen fiber layer of the pars tensa appeared intact until 4 weeks of d
isease.