Acute Otitis Media Ears Research Articles

Paediatric Temporomandibular Joint Septic Arthritis: A Complication of Acute Mastoiditis

Septic Temporomandibular joint (TMJ) arthritis is an unusual complication of acute mastoiditis in children. This is a case of acute mastoiditis in a 7 years old child following an acute otitis media ear infection, which presented with ear discharge, trismus, mastoid area erythema and TMJ swelling and pain. CT scan showed opacification of mastoid temporal bone and TMJ area. Treatment included antibiotics and TMJ abscess surgical drainage. In this case report, we discuss the clinical picture, investigations, treatment and literature review for this case. Multidisciplinary approach (ENT, Paediatrics, and Oral and Maxillofacial surgeons) was mandatory to manage this unusual complication in children.

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

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: 4days (4D) and 8days (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 8days 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.

Factors affecting sound energy absorbance in acute otitis media model of chinchilla

Acute otitis media (AOM) is a rapid-onset infection of the middle ear which results in middle ear pressure (MEP), middle ear effusion (MEE), and structural changes in middle ear tissues. Previous studies from our laboratory have identified that MEP, MEE, and middle ear structural changes are three factors affecting tympanic membrane (TM) mobility and hearing levels (Guan et al., 2014, 2013). Sound energy reflectance or absorbance (EA) is a diagnostic tool increasingly used in clinical settings for the identification of middle ear diseases. However, it is unclear whether EA can differentiate these three factors in an AOM ear. Here we report wideband EA measurements in the AOM model of chinchilla at three experimental stages: unopened, pressure released, and effusion removed. These correspond to the combined and individual effects of the three factors on sound energy transmission. AOM was produced by transbullar injection of Haemophilus influenzae in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent the relatively early and later phase of AOM. In each group of chinchillas, EA at 250–8000 Hz was measured using a wideband tympanometer at three experimental stages. Results show that the effects of MEP, MEE, and tissue structural changes over the frequency range varied with the disease time course. MEP was the primary contributor to reduction of EA in 4D AOM ears and had a smaller effect in 8D ears. MEE reduced the EA at 6–8 kHz in 4D ears and 2–8 kHz in 8D ears and was responsible for the EA peak in both 4D and 8D ears. The residual EA loss due to structural changes was observed over the frequency range in 8D ears and only at high frequencies in 4D ears. The EA measurements were also compared with the published TM mobility loss in chinchilla AOM ears.

Dynamic Properties of Tympanic Membrane in a Chinchilla Otitis Media Model Measured With Acoustic Loading.

Otitis media is the most common infectious disease in young children, which results in changes in the thickness and mechanical properties of the tympanic membrane (TM) and induces hearing loss. However, there are no published data for the dynamic properties of the TM in otitis media ears, and it is unclear how the mechanical property changes are related to TM thickness variation. This paper reports a study of the measurement of the dynamic properties of the TM in a chinchilla acute otitis media (AOM) model using acoustic loading and laser Doppler vibrometry (LDV). AOM was created through transbullar injection of Haemophilus influenzae into the middle ear, and AOM samples were prepared 4 days after inoculation. Vibration of the TM specimen induced by acoustic loading was measured via LDV over a frequency range of 0.1-8 kHz. The experiment was then simulated in a finite element (FE) model, and the inverse-problem solving method was used to determine the complex modulus in the frequency domain. Results from 12 ears (six control and six AOM) show that the storage modulus of the TM from AOM ears was on average 53% higher than that of control ears, while the loss factor was 17.3% higher in control ears than in AOM ears at low-frequency (f < 1 kHz). At high-frequency (e.g., 8000 Hz), there was a mean 40% increase in storage modulus of the TM from AOM compared to control samples. At peak frequency (e.g., 3 kHz), there was a 19.5% increase in loss factor in control samples compared to AOM samples. These findings quantify the changes induced by AOM in the chinchilla TM, namely, a significant increase in both the storage and loss moduli.

Complex modulus of round window membrane over auditory frequencies in normal and otitis media chinchilla ears

To better reveal the mechanical properties of round window membrane (RWM) in normal and pathological ears, the complex modulus of chinchilla RWM was determined by measuring its dynamic behaviour together with the finite element simulation. The acute otitis media (AOM) was created by transbullar injection of Haemophilus influenzae in chinchillas and RWM specimens in AOM ears were prepared four days post inoculation. Vibration of the RWM induced by coil-magnet force stimulation was measured by laser Doppler vibrometry over frequencies of 0.2–8 kHz. A finite element model-based inverse-problem solving method was used to determine the complex modulus of each RWM specimen in the frequency domain. Experimental results of the AOM ears indicated that the resonance frequency decreased by 13.94% compared with the normal ears and the mean storage modulus and loss modulus were decreased by 65% and 32%, respectively.

Factors affecting loss of tympanic membrane mobility in acute otitis media model of chinchilla

Recently we reported that middle ear pressure (MEP), middle ear effusion (MEE), and ossicular changes each contribute to the loss of tympanic membrane (TM) mobility in a guinea pig model of acute otitis media (AOM) induced by Streptococcus pneumoniae (Guan and Gan, 2013). However, it is not clear how those factors vary along the course of the disease and whether those effects are reproducible in different species. In this study, a chinchilla AOM model was produced by transbullar injection of Haemophilus influenzae. Mobility of the TM at the umbo was measured by laser vibrometry in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent relatively early and later phases of AOM. In each group, the vibration of the umbo was measured at three experimental stages: unopened, pressure-released, and effusion-removed ears. The effects of MEP and MEE and middle ear structural changes were quantified in each group by comparing the TM mobility at one stage with that of the previous stage. Our findings show that the factors affecting TM mobility do change with the disease time course. The MEP was the dominant contributor to reduction of TM mobility in 4D AOM ears, but showed little effect in 8D ears when MEE filled the tympanic cavity. MEE was the primary factor affecting TM mobility loss in 8D ears, but affected the 4D ears only at high frequencies. After the release of MEP and removal of MEE, residual loss of TM mobility was seen mainly at low frequencies in both 4D and 8D ears, and was associated with middle ear structural changes. Our findings establish that the factors contributing to TM mobility loss in the chinchilla ear were similar to those we reported previously for the guinea pig ears with AOM. Outcomes did not appear to differ between the two major bacterial species causing AOM in these animal models.

Comparison of Eardrum Mobility in Acute Otitis Media and Otitis Media With Effusion Models

To investigate the eardrum mobility difference between acute otitis media (AOM) and experimental otitis media with effusion (OME). Thirty-three Hartley guinea pigs were included in this study. The AOM and OME were created by transbullar injection of Streptococcus pneumoniae and lipopolysaccharide into the middle ear, respectively. Three days after inoculation, the morphologic changes of the middle ear were assessed with otoscopy and histologic sections. Vibrations of the tympanic membrane (TM) at umbo in response to pure tone sound were measured using laser Doppler vibrometry. The purulent effusion, ossicular adhesion, and thickened TM and middle ear mucosa were observed in the AOM ears, and the OME ears had serous effusion and less thickened TM and mucosa in the middle ear. The displacement of TM in AOM was lower than that in OME ears, especially at 0.2 to 4 kHz. The TM mobility difference between the AOM and OME ears were mainly caused by the middle ear ossicular structure changes during the bacterial infection in AOM.

Mechanisms of Tympanic Membrane and Incus Mobility Loss in Acute Otitis Media Model of Guinea Pig

Acute otitis media (AOM) is a rapid infection of middle ear due to bacterial or viral invasion. The infection commonly leads to negative pressure and purulent effusion in the middle ear. To identify how these changes affect tympanic membrane (TM) mobility or sound transmission through the middle ear, we hypothesize that pressure, effusion, and structural changes of the middle ear are the main mechanisms of conductive hearing loss in AOM. To test the hypothesis, a guinea pig AOM model was created by injection of Streptococcus pneumoniae. Three days post inoculation, vibration of the TM at umbo in response to input sound in the ear canal was measured at three experimental stages: intact, pressure-released, and effusion-drained AOM ears. The vibration of the incus tip was also measured after the effusion was removed. Results demonstrate that displacement of the TM increased mainly at low frequencies when pressure was released. As the effusion was removed, the TM mobility increased further but did not reach the level of the normal ear at low frequencies. This was caused by middle ear structural changes or adhesions on ossicles in AOM. The structural changes also affected movement of the incus at low and high frequencies. The results provide new evidence for understanding the mechanism of conductive hearing loss in AOM.

Dynamic properties of round window membrane in guinea pig otitis media model measured with electromagnetic stimulation

The round window, one of two openings into the cochlea from the middle ear, plays an important role in hearing and is known to be structurally altered during otitis media. However, there have been no published studies systematically describing the changes in biomechanical properties of the round window membrane (RWM) that accompany bacterial otitis media. Here we describe the occurrence of significant changes in the dynamic properties of the RWM between normal guinea pigs and those with acute otitis media (AOM) that are detectable by electromagnetic force stimulation and laser Doppler vibrometry (LDV) measurements. AOM was induced by transbullar injection of streptococcus pneumoniae into the middle ear, and RWM specimens were prepared three days after challenge. Vibration of the RWM induced by coil-magnet coupling was measured by LDV over frequencies of 0.2–40 kHz. The experiment was then simulated in a finite element model, and the inverse-problem solving method was used to determine the complex modulus in the frequency domain and the relaxation modulus in the time domain. Results from 18 ears (9 control ears and 9 AOM ears) established that both the storage modulus and loss modulus of the RWM from ears with AOM were significantly lower than those of RWM from uninfected ears. The average decrease of the storage modulus in AOM ears ranged from 1.5 to 2.2 MPa and the average decrease of the loss modulus was 0.025–0.48 MPa. Our findings suggest that middle ear infection primarily affects the stiffness of the RWM due to the morphological changes that occur in AOM ears. We also conclude that the coil-magnet coupling method for assessment of RWM function may provide a valuable new approach to characterizing the mechanical response of the RWM when reverse driving is selected for middle ear implantable devices.This article is part of a Special Issue entitled “MEMRO 2012”.

Preliminary study of proinflammatory cytokines and chemokines in the middle ear of acute otitis media due to Alloiococcus otitidis

Alloiococcus otitidis is a newly discovered organism frequently detected in otitis media. However, the association of the organism with the development of otitis media has not been disclosed in detail yet. In the middle ear, proinflammatory cytokines and chemokines are released in association with infection by pathogens, and these cytokines contribute to the induction of an inflammatory reaction. To investigate the profile of inflammation-related cytokines in the acute phase of A. otitidis infection, we analyzed the release of proinflammatory cytokines and chemokines in middle ear effusions of acute otitis media due to A. otitidis, in comparison with acute otitis media due to the well-known Gram-positive middle ear pathogen Streptococcus pneumoniae. The amounts of proinflammatory cytokines (IL-8, IL-1beta, IL-6, TNF-alpha) and CXC chemokines (IP-10, I-TAC) were significantly increased in the A. otitidis group as well as in the S. pneumoniae group. Various inflammation-related cytokines/chemokines were induced in the A. otitidis-infected middle ear, and the profile of cytokines was very similar to that in S. pneumoniae infection. This preliminary study suggests that A. otitidis has the potential to induce these cytokines, contributing to the development of an inflammatory reaction in the middle ear cavity in a similar manner to S. pneumoniae.

Otoscopic and Tympanometric Findings in Acute Otitis Media Yielding Dry Tap at Tympanocentesis

The value of tympanometry in detection of middle ear effusion (MEE) has been widely studied in otitis media with effusion. There has been no direct comparison of tympanometric and tympanocentesis (TAP) findings in acute otitis media (AOM). We compared otoscopic, tympanometric and TAP findings in AOM including cases of AOM without effusion. In a study of AOM treatment of 90 children, a tympanogram was obtained, and TAP was performed before and after 5 days of treatment. Subjects were followed with otoscopy and tympanometry every 2 weeks for 3 months or until the MEE cleared. In 130 AOM ears, otoscopic, tympanometric and TAP findings were available; MEE was obtained from 110 ears. Of 20 ears with a dry tap, 18 had abnormal tympanogram and otoscopic findings. With TAP findings as the standard, sensitivity and positive predictive value of type B tympanogram were 97 and 87%, respectively. Of 18 AOM ears yielding dry tap, 2 yielded MEE 5 days later, and 8 continued with evidence of MEE 5 days-12 weeks later. Five subjects with 8 AOM ears yielding dry tap were lost to follow-up; all had short duration of clinical symptoms. Although otoscopic and tympanometric findings suggested the presence of MEE in AOM, MEE was unobtainable by TAP in 14% of cases. Dry tap cases likely represent early AOM before accumulation of detectable MEE. However, technical difficulty in obtaining small amounts of or highly viscous MEE could not be excluded. Sensitivity and positive predictive value of abnormal tympanograms in detection of MEE in AOM cases are comparable with those in otitis media with effusion.

Prognostic factors for persistent middle ear effusion after acute otitis media in children.

The present study was carried out to determine the clinical course of acute otitis media (AOM) in children and to analyze the risk factors that lead to persistent effusion. One hundred and twenty children aged 9 months to 10 years diagnosed as having AOM were included in this study. Sixty-two children (52%) recovered from AOM without middle ear effusions within a month. In 26 cases (22%), middle ear effusions resolved after 1 to 3 months, while 32 children (26%) had persistent effusions for more than 3 months after the onset of acute inflammation. Statistical analysis between the group showing quick recovery and that with persistent effusion was carried out in relation to various clinical factors at the onset. The significant risk factors were: younger age, bilateral AOM, presence of otorrhea, tympanogram type B or C2 on an AOM ear. Moreover, the most significant prognostic factor was a tympanogram type B or C2 on an opposite ear at the acute onset. On the other hand, factors such as sex, fever, history of otitis media, season at onset or complications did not correlate with the duration of persistent effusion. From these results we conclude that careful examination should be performed not only on the ear with AOM but also on the opposite ear in order to predict the course of otitis media.