Long-term effect of middle ear disease on temporal processing and P300 in two different populations of children.

BACKGROUND/OBJECTIVE: The effects of otitis media on the function of the central auditory nervous system in different populations is unknown. Understanding how the history of otitis media affects children from different nations will guide health professionals worldwide on the importance of adequate auditory stimulus in childhood. For this reason, the aim of the present study was to investigate the long-term auditory effects of middle ear disease on temporal processing and P300 in two different populations of children: Australian and Brazilian. METHODS: Temporal processing tests (Frequency Pattern Tests-FPT and Gaps in noise-GIN) and P300 were measured in 68 Brazilian and Australian children, aged between 8 to 14 years. The Brazilian otitis media group (BrOM) and Australian otitis media group (AusOM) consisted of 20 children each who had a documented history of otitis media. Control groups of 14 children (BrControl and AusControl) were also recruited from each country, all with no documented history of otitis media. RESULTS: The BrOM group showed significantly poorer performance (p<0.001) for FPT and the GIN compared to BrControl. The P300 response showed significantly longer mean latencies (p = 0.02) compared to BrControls. The AusOM group also showed significant delayed latency of P300 (p = 0.04) compared to the AusControl. The FPT showed significantly poorer performance (p = 0.04) compared to AusControls. The two otitis media groups showed no significant differences between each other on P300. Significant differences were seen however in temporal processing tests performance between the two cohorts for the otitis media groups. The BrOM group had significantly poorer responses (p<0.001) for FPT and GIN compared to the AusOM group. CONCLUSIONS: These findings support that although differences exist between BrOM and AusOM groups, otitis media can be demonstrated to affect the underlying mechanisms of the P300 measures and behavioral auditory responses in two different populations of children.

The effects of oral supplements with Sambucus nigra, Zinc, Tyndallized Lactobacillus acidophilus (HA122), Arabinogalactans, vitamin D, vitamin E and vitamin C in otitis media with effusion in children: a randomized controlled trial.

OBJECTIVE: To evaluate the ability of oral supplements with immune-stimulating molecules (Sambucus nigra, Zinc, Tyndallized Lactobacillus acidophilus (HA122), Arabinogalactans, vitamin D, vitamin E and vitamin C) to reduce the inflammation of the upper airway tract and improve the outcome of otitis media with effusion (OME) in children. PATIENTS AND METHODS: Randomized controlled trial. One-hundred ninety-eight children (CI 95%: 12-96 months) were divided into four groups. Group 1 (48 subjects) received 10 ml of oral supplements (OS) with immune-stimulating molecules for three months (20 days consecutively, then 10 days of suspension - the therapeutic scheme was repeated three times); Group 2 (54 children) underwent treatment with 10 ml of OS for 90 consecutive days; Group 3 (48 subjects) received 15 ml of OS for 45 consecutive days; a control group (48 children) underwent the standard treatment for rhinitis and OME. Outcome measures included otoscopy, tympanometry, fibroendoscopy, and the pure tone audiometry (PTA) at T0 (before treatment), T1 (45 days after treatment), and T2 (90 days after treatment). RESULTS: All children treated with OS showed a reduction of Upper Airway Infection (UAI) episodes and OME compared to the control group independent of the administration method and posology. The three groups treated with OS showed statistically significant differences between T0 and T2 for otoscopy, tympanometry, fibroendoscopy, and PTA. In Group 2, the otoscopy and the tympanometry scores improved at T1. Group 2 and 3 had better PTA results than Group 1. CONCLUSIONS: OS with immune-stimulating molecules should be considered as a supporting therapy in children affected by recurrent episodes of UAI associated with OME due to their capacity to improve the immune response and reduce the inflammatory phenomena. OS can improve the fibroendoscopic findings by restoring middle ear ventilation, in addition to their ability to reduce inflammation in the middle ear.

Contrasting Effects of Pressure Compensation on TEOAE and DPOAE in Children With Negative Middle Ear Pressure.

In children with normal cochlear acuity, middle ear fluid often abolishes otoacoustic emissions (OAEs), and negative middle ear pressure (NMEP) reduces them. No convincing evidence of beneficial pressure compensation on distortion product OAE (DPOAE) has yet been presented. Two studies aimed to document effects of NMEP on transient OAE (TEOAE) and DPOAE. In Study 1, TEOAE and DPOAE pass/fail responses were analyzed before and after pressure compensation in 50 consecutive qualifying referrals having NMEP from -100 to -299 daPa. Study 2 concentrated on DPOAE, recording both amplitude (distortion product amplitude) and signal-to-noise ratio (SNR) before and after pressure compensation. Of the 20 participants, 5 had both ears qualifying. An effect of compensation on meeting a pass criterion was present in TEOAE for both left and right ear data in Study 1 but not demonstrable in DPOAE. In Study 2, the distortion product amplitude compensation effect was marginal overall, and depended on recording frequency band. SNR values improved moderately after pressure compensation in the two (overlapping) sets of single-ear data. In the five cases with both ears qualifying, a stronger compensation effect size, over 3 dB, was seen. The absolute dependence of SNR on frequency was also strongly replicated, but in no analysis, the frequency × compensation interaction was significant. Independent of particular frequency range, the data support a limited SNR improvement in 2 to 3 dB for compensation in DPOAE, with slightly larger effects in ears giving SNRs between 0 dB and +6 dB, where pass/fail cutoffs would generally be located.

Tubomanometry value as an associated factor for medication outcomes in adult acute otitis media with effusion.

Tubomanometry (TMM) is a relatively novel method for testing the eustachian tube (ET) function, which is speculated to be closely related to otitis media with effusion (OME). The purpose of this study is to explore the predictive power of TMM value for medication outcomes in adult acute OME. A cohort of 41 adult acute OME patients with 53 affected ears was studied retrospectively. All these patients completed a 2-week treatment including oral Myrtol Standardized Enteric capsules, nasal steroid, and oral antihistamine. The results showed that the response rate was 41.5% (22/53). The ratio of tympanometry C and TMM value differed significantly between responders and non-responders (P < 0.05), and the TMM value is the only predictive variable for treatment outcomes (P < 0.001, odds ratio 1.873). A ROC analysis of the TMM value for the treatment outcome showed that the area under the curve could achieve 0.773 (P < 0.001), while the optimal cutoff value calculated by Youden index was 1.5, with 72.7% sensitivity and 74.2% specificity. The response rate of ears with 2-6 TMM values could reach 66.7% (16/24), which was significantly higher than that of ears with TMM values 0-1, 20.7% (6/29) (P < 0.001). These findings showed that acute OME patients with a high TMM value and tympanometry C of the affected ear could potentially benefit from medication. The TMM value was an independent predictive factor of the treatment outcomes that could guide treatment decisions.

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.

Vibromechanical assessment of active middle ear implant stimulation in simulated middle ear effusion: a temporal bone study.

HYPOTHESIS: Active middle ear implant (AMEI) generated vibromechanical stimulation of the ossicular chain (ossicular chain vibroplasty [OCV]) or the round window (round window vibroplasty [RWV]) is not significantly affected by simulated middle ear effusion in a human temporal bone model. BACKGROUND: OCV and RWV may be employed for sensorineural, mixed, and conductive hearing losses. Although middle ear effusions may be encountered across patient populations, little is known about how effusions may affect AMEI vibromechanical efficiency. METHODS: Laser Doppler vibrometry of stapes velocities (SVs) were performed in a human temporal bone model of simulated effusion (N = 5). Baseline measurements to acoustic sinusoidal stimuli, OCV, and RWV (0.25-8 kHz) were made without effusion. The measurements were repeated with simulated middle ear effusion and compared with baseline measurements. Data were analyzed across 3 frequency bands: low (0.25-1 kHz), medium (1-3 kHz), and high (3-8 kHz). RESULTS: Acoustic stimulation with simulated middle ear effusion resulted in a significant (p < 0.001) frequency-dependent attenuation of SVs of 4, 10, and 7 dB (low, medium, and high ranges, respectively). OCV in simulated effusion resulted in attenuated SVs of 1, 5, and 14 dB (low, medium, and high) compared to without effusion; however, this attenuation was not significant (p = 0.07). Interestingly, in the setting of RWV, simulated effusion resulted in significantly (p = 0.001) increased SVs of 16, 11, and 8 dB (low, medium, and high). A 3-dB variance in AMEI efficiency was observed in repeated measurements in a single temporal bone. CONCLUSION: The efficiency of OCV was not significantly affected by the presence of a middle ear effusion. Improved efficiency, however, was observed with RWV.

Wideband aural acoustic absorbance predicts conductive hearing loss in children.

OBJECTIVE: This study tested the hypothesis that wideband aural absorbance predicts conductive hearing loss (CHL) in children medically classified as having otitis media with effusion. DESIGN: Absorbance was measured in the ear canal over frequencies from 0.25 to 8 kHz at ambient pressure or as a swept tympanogram. CHL was defined using criterion air-bone gaps of 20, 25, and 30 dB at octaves from 0.25 to 4 kHz. A likelihood-ratio predictor of CHL was constructed across frequency for ambient absorbance, and across frequency and pressure for absorbance tympanometry. Performance was evaluated at individual frequencies and for any frequency at which a CHL was present. STUDY SAMPLE: Absorbance and conventional 0.226-kHz tympanograms were measured in children of age three to eight years with CHL and with normal hearing. RESULTS: Absorbance was smaller at frequencies above 0.7 kHz in the CHL group than the control group. Based on the area under the receiver operating characteristic curve, wideband absorbance in ambient and tympanometric tests were significantly better predictors of CHL than tympanometric width, the best 0.226-kHz predictor. Accuracies of ambient and tympanometric wideband absorbance did not differ. CONCLUSIONS: Absorbance accurately predicted CHL in children and was more accurate than conventional 0.226-kHz tympanometry.

Effect of middle ear fluid on sound transmission and auditory brainstem response in guinea pigs.

Combined measurements of middle ear transfer function and auditory brainstem response (ABR) in live guinea pigs with middle ear effusion (MEE) are reported in this paper. The MEE model was created by injecting saline into the middle ear cavity. Vibrations of the tympanic membrane (TM), the tip of the incus, and the round window membrane (RWM) were measured with a laser vibrometer at frequencies of 0.2-40 kHz when the middle ear fluid increased from 0 to 0.2 ml (i.e., full fill of the cavity). The click and pure tone ABRs were recorded as the middle ear fluid increased. Fluid introduction reduced mobility of the TM, incus and RWM mainly at high frequencies (f > 1 kHz). The magnitude of this reduction was related to the volume of fluid. The displacement transmission ratio of the TM to incus varied with frequency and fluid level. The volume displacement ratio of the oval window to round window was approximately 1.0 over most frequencies. Elevation of ABR thresholds and prolongation of ABR latencies were observed as fluid level increased. Reduction of TM displacement correlated well with elevation of ABR threshold at 0.5-8 kHz. Alterations in the ratio of ossicular displacements before and after fluid induction are consistent with fluid-induced changes in complex ossicular motions.

Accuracy of velocity distortion product otoacoustic emissions for estimating mechanically based hearing loss.

Distortion product otoacoustic emissions (DPOAEs) measured as vibration of the human eardrum have been successfully used to estimate hearing threshold. The estimates have proved more accurate than similar methods using sound-pressure DPOAEs. Nevertheless, the estimation accuracy of the new technique might have been influenced by endogenous noise, such as heart beat, breathing and swallowing. Here, we investigate in an animal model to what extent the accuracy of the threshold estimation technique using velocity-DPOAEs might be improved by reducing noise sources. Velocity-DPOAE I/O functions were measured in normal and hearing-impaired anaesthetized guinea pigs. Hearing loss was either conductive or induced by furosemide injection. The estimated distortion product threshold (EDPT) obtained by extrapolation of the I/O function to the abscissa was found to linearly correlate with the compound action potential threshold at the f(2) frequency, provided that furosemide data were excluded. The standard deviation of the linear regression fit was 6 dB as opposed to 8 dB in humans, suggesting that this accuracy should be achievable in humans with appropriate improvement of signal-to-noise ratio. For the furosemide animals, the CAP threshold relative to the regression line provided an estimate of the functional loss of the inner hair cell system. For mechanical losses in the middle ear and/or cochlear amplifier, DPOAEs measured as velocity of the umbo promise an accuracy of hearing threshold estimation comparable to classical audiometry.

The development of frequency weighting for speech in children with a history of otitis media with effusion.

OBJECTIVES: To determine the effect of chronic (recurrent) otitis media with effusion (OME) on frequency weighting in the perception of speech in noise. It was hypothesized that children with a history of OME weight speech information in the mid frequency region higher than control children. DESIGN: This is a matched cohort study looking at differences in frequency weighting in 12 children with a history of OME 1 to 2 wks after placement of tympanostomy tubes compared with 21 control children. Children were tested on their ability to identify key words in sentences presented in speech-shaped noise. The frequency content of the sentences was manipulated to determine the relative importance of frequencies in the regions of 1, 2, and 4 kHz. The frequency bands selected were 798 to 1212 Hz (low band), 1575 to 2425 Hz (mid band), and 3000 to 5000 Hz (high band). Initial testing involved adaptive runs where a speech-shaped masker was held at a constant level and the level of the speech with all three bands present varied. Once a level corresponding to 85% to 90% correct was identified, novel sentences were then presented at this signal-to-noise ratio in fixed block runs, with all bands present, or with one of the three bands omitted. RESULTS: The children in the OME group achieved 85% to 90% correct at a lower signal-to-noise ratio than controls in the adaptive testing, where all three speech bands were present. Fixed block testing indicated that children with OME history gave more weight to speech frequencies in the region of 2000 Hz compared with the age-matched control group. CONCLUSIONS: The results are consistent with an interpretation that the development of frequency weighting in the perception of speech can be affected by a history of OME.

Multifrequency tympanometry in neonatal intensive care unit and well babies.

BACKGROUND: Conventional low probe tone frequency tympanometry has not been successful in identifying middle ear effusion in newborn infants due to differences in the physiological properties of the middle ear in newborn infants and adults. With a rapid increase in newborn hearing screening programs, there is a need for a reliable test of middle ear function for the infant population. In recent years, new evidence has shown that tympanometry performed at higher probe tone frequencies may be more sensitive to middle ear disease than conventional low probe tone frequency in newborn infants. PURPOSE: The main goal of this study was to explore the characteristics of the normal middle ear in the NICU (neonatal intensive care unit) and well babies using conventional and multifrequency tympanometry (MFT). It was also within the scope of this study to compare conventional and MFT patterns in NICU and well babies to already established patterns in adults to identify ways to improve hearing assessment in newborns and young infants. METHODS: Three experiments were conducted using standard and MFT involving healthy babies and NICU babies. NICU babies (n = 33), healthy three-week-old babies (n=16), and neonates on high-priority hearing registry (HPHR) (n=42) were tested. Thirty-two ears of 16 healthy Caucasian adults (compared to well-babies) and 47 ears of 26 healthy Caucasian adults (compared to NICU babies) were also included in this study. RESULTS: The distribution of the Vanhuyse patterns as well as variation of admittance phase and peak compensated susceptance and conductance at different probe tone frequencies was also explored. In general, in both well babies and NICU babies, 226 Hz tympanograms are typically multipeaked in ears that passed or referred on transient otoacoustic emission (TEOAE), limiting the specificity and sensitivity of this measure for differentiating normal and abnormal middle ear conditions. Tympanograms obtained at 1 kHz are potentially more sensitive and specific to presumably abnormal and normal middle ear conditions. Tympanometry at 1 kHz is also a good predictor of presence or absence of TEOAE.

Wideband reflectance in neonatal intensive care units.

BACKGROUND: Wideband reflectance (WBR) provides important information about middle ear function and can explain variations in how the middle ear receives, absorbs, and transmits sound energy across a wide range of frequencies. However, as of yet, few normative studies have been published to guide clinicians in the practical applications of WBR. WBR has been measured more extensively in well babies than in neonatal intensive care unit (NICU) babies, who have significantly higher incidence of otitis media with effusion (OME). PURPOSE: The goal of this study was to explore the characteristics of the middle ear while using energy reflectance (ER) and normalized admittance in NICU babies who passed automated auditory brainstem response (AABR) and evoked otoacoustic emission (EOAE) hearing screening criteria and to compare these characteristics to patterns in normal hearing adults. This study was done to identify ways to implement WBR so it could improve hearing assessment in newborns. METHODS: Thirty-one neonatal intensive care unit (NICU) babies with an average gestational age (GA) of 37.8 weeks (range: 32-51 weeks) and 56 adults with normal hearing between the ages of 18 and 32 years served as subjects in this study. NICU babies and adults were tested using multifrequency tympanometry (MFT) and WBR. RESULTS: WBR can be obtained on what appears to be a majority of NICU babies without other abnormal findings. Maximum absorption of the incident energy appears to occur at a narrower range of frequencies in normal NICU babies in comparison to normal hearing adults. This range becomes even narrower in NICU babies who fail EOAE screening. In most NICU babies who failed EOAE screening, ER values were closer to 1 (most incident energy is reflected) at a frequency below 3000 Hz. The measurements of normalized acoustic admittance may also be very useful and may supplement ER and tympanometric data in evaluating middle ear status.

Multifield coupled finite element analysis for sound transmission in otitis media with effusion.

In this paper, a newly constructed three-dimensional finite element (FE) model of the human ear based on histological sections of a left ear temporal bone is reported. The otitis media with effusion was simulated in the model with variable fluid levels in the middle ear. The interfaces among the air, structure, and fluid in the ear canal and middle ear cavity were identified and the acoustic-structure-fluid coupled FE analysis was conducted when the middle ear fluid level was varied from zero to full fill of the cavity. The results show how the displacements of the tympanic membrane and stapes footplate or the middle ear transfer function is affected by fluid in the cavity across the auditory frequencies. Comparison of model results with measured data in temporal bones indicates that this model has the capability to extend FE analysis into pathological ears such as otitis media with visualized fluid-air interfaces inside the middle ear structures.

CO2 laser myringotomy in children with otitis media with effusion.

BACKGROUND: The study aimed to evaluate the clinical application of CO2 laser myringotomy in children with otitis media with effusion (OME) under topical anaesthesia in an office setting. METHODS: Laser myringotomy was performed with the CO2 laser Otoscan (OtoLAM) in 54 children (73 ears) with OME. The procedure on the tympanic membrane was performed under topical anaesthesia using Bonain's solution or 10 per cent Xylocaine (lidocaine) solution for 30 minutes before surgery. A circular perforation was created with a power of 15 W, single pulse duration of 200 msec and a scanned area of 1.9 mm in diameter. RESULTS: The mean healing time was 2.51 weeks (range 1-5 weeks). Effusion content was not a predictive prognostic factor for perforation healing time. Perforation location over anterior inferior or posterior inferior quadrants was not a predictive factor for perforation healing time. Xylocaine was the more effective anaesthestic. The OME resolution rate was 73 per cent. CONCLUSION: Laser myringotomy provides intermediate duration middle-ear ventilation. It could be beneficial in selected children with OME.

The role of soluble interleukin-4 receptor and interleukin-5 antibody in preventing late-phase allergy-induced eustachian tube dysfunction.

OBJECTIVES: We investigated the role of soluble interleukin (IL)-4 receptors (sIL-4R) and IL-5 antibodies (IL-5Ab) in preventing allergic eustachian tube dysfunction (ETD) and middle ear effusion (MEE). STUDY DESIGN: Brown-Norway rats were sensitized to ovalbumin (OVA) and challenged transtympanically. Two groups of rats received either IL-4R or IL-5Ab transtympanically 1 hour before challenge. Three additional groups were used as controls. Following the second transtympanic challenge, the ventilatory and clearance functions of the eustachian tube (ET) were assessed at 0, 2, and 8 hours. Histology was prepared using cut paraffin sections stained with hematoxylin and eosin. RESULTS: sIL-4R-pretreated rats showed no significant changes in ventilatory or clearance functions of the ET or inflammatory changes in ET mucosa, whereas IL-5Ab pretreatment showed significant late ventilatory and clearance dysfunction as well as inflammatory mucosal changes. CONCLUSION: These data demonstrate that the late-phase allergic inflammatory response that leads to subsequent formation of ETD and MEE is prevented by pretreatment with sIL-4R and, more modestly, with IL-5Ab.

Changes in external ear resonance after ventilation tube (Grommet) insertion in children with otitis media with effusion.

OBJECTIVE: As otitis media with effusion is common in children, the effects of a ventilation tube should be taken into account in the prescription of hearing aids for children. In ears with a ventilation tube, the external auditory canal communicates directly with the middle ear space, and so the impedance of the middle ear may change. Consequently, this will affect external-ear resonance. The aim of this study is to observe the effects of the tympanic membrane perforations caused by the ventilation tube on external-ear resonance. We selected 30 ears with otitis media with effusion to measure external-ear resonance before and after ventilation tube insertion. We compared the external-ear resonance of a control group with that of the otitis media with the effusion group and two types of ventilation-tube groups, respectively. In the subjects who have otitis media with effusion, the average gain of the peak resonance was larger than that in the control group. After ventilation-tube insertion, the amplitude of the gain decreased to the same level as the control group, but a characteristic negative gain appeared around 1000 Hz in about half of all cases. This negative gain was observed more frequently in the ventilation tube with a larger diameter. The raised peak resonance gain in the otitis media with effusion group decreased to a level roughly the same as that of the control group after ventilation-tube insertion. Provision of an additional gain in the low frequencies around 1000 Hz should be considered for patients with a ventilation tube when prescribing hearing aids.

Effects of topical otic preparations on hearing in chronic otitis media.

Most of the topical otic preparations have been shown to cause ototoxicity. In this study ciprofloxacin hydrochloride, a relatively new topical agent, and gentamicin sulfate were studied in two groups of 20 patients with chronic otitis media. Patients were randomly selected to receive either ciprofloxacin (200 microg/ml) or gentamicin sulfate (5 mg/ml) locally, five drops three times a day for 10 days. Clinical response was seen in 20 of 20 patients in the ciprofloxacin group compared with 6 of 20 patients in the gentamicin group. Audiometric evaluation revealed no significant ototoxic effect in either group. In fact, hearing thresholds were slightly better than pretreatment levels in both groups.

The herbal medicine, sairei-to, enhances the mucociliary activity of the tubotympanum in the healthy guinea pig.

Mucociliary dysfunction in the tubotympanum is deeply reflected in the clinical manifestations of otitis media with effusion (OME), and clinical application of pharmacological agents with ciliostimulatory action might therefore enhance the mucociliary clearance function of the tubotympanum to more effectively eliminate middle ear effusions to the pharynx. A herbal medicine, sairei-to, enhances the in vitro ciliary activity of the middle ear during culture. However, this ciliostimulatory effect is not always applicable to the mucociliary system in situ, which may be deteriorated following oral administration of sairei-to. The present study therefore aimed at investigating the in vivo effect of sairei-to on the mucociliary system in the tubotympanum of the guinea pig. Thirty healthy guinea pigs were used. Ten animals were treated with oral administration of physiologic saline solution for 14 successive days. The remaining animals were treated with oral administration of 120 or 600 mg/kg body weight of sairei-to for 14 successive days. Each animal was used for examination of the ciliary activity and mucociliary clearance time of the tubotympanum, 24 h after the final treatment. No significant changes in either ciliary activity or mucociliary clearance time of the tubotympanum were observed upon administration of 120 mg/kg of sairei-to, which was equivalent to the clinical human dosage. By contrast, oral administration of 600 mg/kg of sairei-to significantly enhanced the ciliary activity, but failed to significantly accelerate mucociliary clearance in the tubotympanum, although the mean value of the clearance time became shorter. Therefore, our results suggest that sairei-to to some extent stimulates the function of the mucociliary system. In conclusion, the herbal medicine, sairei-to, might be useful in the treatment of OME, and preventive administration of this drug may be a new therapy in the treatment of recurrent OME.

The herbal medicine, sairei-to, prevents endotoxin-induced otitis media with effusion in the guinea pig.

With current pharmacotherapy, otitis media with effusion (OME) is often recurrent and even develops to become chronic. There is now considerable experimental and clinical evidence that the cilia in the tubotympanum play an important part in the prevention of OME. A herbal medicine, sairei-to, has been shown to stimulate the ciliary activity in vitro, and oral administration of the medicine also stimulated the ciliary activity in the tubotympanum rather than physiological states. This study was designed to investigate whether oral administration of sairei-to could prevent experimental OME in the guinea pig. A total of 120 guinea pigs were used. The control group was treated with intratympanic injection of 0.1 ml of physiologic saline solution. The saline-control group was treated with oral administration of physiologic saline solution for 14 successive days. The low-dosage group and the high-dosage group were treated with oral administration of 120 and 600 mg/kg of sairei-to for 14 successive days, respectively. The saline-control group, the low-dosage group and the high-dosage group were then treated with intratympanic injection of 0.1 ml of lipopolysaccharide solution (100 micrograms/ml) derived from Klebsiella pneumoniae. All 10 animals from the 4 groups were sacrificed 1, 3, and 7 days after the intratympanic injection, to examine ciliary activity, mucociliary clearance time, and mucosal pathology of the tubotympanum. The saline-control group exhibited middle ear effusions and pathologies similar to human OME. The incidence of middle ear effusions in the low-dosage and the high-dosage groups was somewhat reduced compared with the saline-control group. The ciliary activity in the tubotympanum was significantly reduced in the saline-control and low-dosage groups compared with the normal-control group. By contrast, the magnitude of reduction in ciliary activity was much smaller in the high-dosage group. The ciliary activity especially in the Eustachian tube and the middle ear close to the tympanic orifice at 3 and 7 days in the high-dosage group was not significantly different from that in the normal-control group. Mucociliary clearance time in the high-dosage group was not different from that in the normal-control group throughout the observation period. The groups treated with sairei-to, especially the high-dosage group, exhibited much milder pathological changes in the tubotympanum than did the saline-control group. In conclusion, clinical application of sairei-to could be an effective measure to prevent the occurrence of OME and also the recurrence of the disease, especially OME-prone individuals.

Tympanometry and otoacoustic emissions in a cohort of special care neonates.

Otoacoustic emission (OAE) screening and oto-admittance testing (678 Hz probe tone) were performed on both ears of 84 special care neonates, as part of a larger study of middle-ear effusion in neonates and infants. OAE results, tympanometry, and acoustic reflex results are all strongly and significantly associated. No evidence was found of any maturational effects in the results. Based on the findings, a tentative classification scheme for neonatal tympanograms is suggested. We conclude that 678 Hz tympanometry is a useful indicator of middle-ear status in very young babies, and that middle-ear effusion does strongly affect OAEs in neonates. OAEs are also strongly affected by negative middle-ear pressure (MEP), and mean MEP in ears failing OAE screens was significantly more negative than in those passing. The prevalence of abnormal tympanometry, which may indicate middle-ear effusion or dysfunction, was 20% of ears (29% of babies) in this group. It appears that middle-ear effusion could account for about half of the ears failing an OAE screen on the special care baby unit. We also find that length of stay on the special care baby unit is an important risk factor for development of middle-ear effusion: those on the unit for over 30 days have about four times the risk of bilateral abnormal tympanometry.