Surface Motion of Tympanic Membrane in a Chinchilla Model of Acute Otitis Media

Abstract

The conductive hearing loss caused by acute otitis media (AOM) is commonly related to a reduction of the tympanic membrane (TM) mobility in response to sound stimuli. However, spatial alterations of the TM surface motion associated with AOM have rarely been addressed. In this study, the TM surface motion was determined using scanning laser Doppler vibrometry (SLDV) in a chinchilla model of AOM. The AOM was established by transbullar injection of nontypeable Haemophilus influenzae. The TM surface vibration was measured in control (uninfected) animals and two AOM groups of animals: 4 days (4D) and 8 days (8D) post inoculation. To quantify the effect of middle ear pressure in those infected ears, the SLDV measurement was first conducted in unopened AOM ears and then in middle ear pressure released ears. Results showed that middle ear infection generally reduced the TM displacement across the entire surface, but the reduction in the umbo displacement over the time course, from 4 to 8 days post inoculation, was less than the reduction in the displacement at the center of each quadrant. The presence of middle ear fluid shifted the occurrence of traveling-wave-like motion on the TM surface to lower frequencies. The observation of the spatial variations of TM surface motion from this study will help refine our understanding of the middle ear sound transmission characteristics in relation to AOM.

Optical coherence tomographic measurements of the sound-induced motion of the ossicular chain in chinchillas: Additional modes of ossicular motion enhance the mechanical response of the chinchilla middle ear at higher frequencies

“…OCT measurements complement other technologies. Scanning laser-Doppler vibrometry can measure motions with higher frequency resolution than is easily achievable with OCT, but it cannot assess the motion of the incus and stapes behind the TM or define the structure of the ossicles (Ball et al 1997, Wang andGan 2018). Furthermore, gathering the number of point data measurements required to adequately describe the motion of the manubrium, incus and stapes would be time consuming.…”

The chinchilla animal model for hearing science and noise-induced hearing loss

“…The chinchilla is considered a gold standard animal model for various diseases of the middle ear, including otitis media, stapes fixation, and cholesteatoma (Lupo et al , 2009; Martin, 2012; Guan et al , 2014; Guan et al , 2015; Wang and Gan, 2018). Chinchillas have also been used to evaluate the strength of various diagnostic tests of middle-ear function (e.g., multifrequency tympanometry has been shown to provide information that is not available in the 226-Hz tympanogram; Margolis et al , 1995).…”