Prospective Validation of Tubomanometry in Children With Normal Eustachian Tube Function

OBJECTIVES

Tubomanometry (TMM), described initially by Estève, is a relatively new manometric method for testing the eustachian tube function (ETF). This study presents the analysis of the measurement of ETF of healthy children by TMM, which has, to date, not been properly evaluated. The objectives of the study were to establish normative data for TMM and to demonstrate TMM as a reliable and valid method for measuring ETF in children.

DESIGN

The evaluation, after initial power analysis, comprised 35 children from 6 to 15 years of age with an intact tympanic membrane, no severe ET dysfunction, and less than three inflammations of the middle ear in their medical history. TMM was performed twice at three pressure levels for both ears. Statistical assessment of the various parameters of TMM was performed with emphasis on the R value and possible age dependency.

RESULTS

The 90th percentile for the R value was calculated to be 1.12. No clinically relevant age effect regarding the use of TMM as a screening method for children was found. Healthy children showed an opening within normal limits for the so-called R value in 88%; a delayed opening was measured in 6%, and rarely no opening was measured in 2%.

CONCLUSIONS

TMM is a reliable tool for measuring ETF in children. The normal limit for the R value should be set at 1.12. The proposed measuring algorithm and results can be used to calculate sensitivity and specificity in a future study.

["Step-up"surgical treatment strategy for patulous Eustachian tube]

Patients with patulous Eustachian tubes(PET) usually suffer from annoying symptoms, such as tinnitus, autophony and aural fullness, due to the excessive opening of the Eustachian tube. There is no uniform standard of treatment, and conservative therapy combined with"Stepup"surgical intervention strategy is the main treatment. In this article, we reviewed various surgical treatments of patulous Eustachian tube in recent years, including key points of surgical operation, effectiveness, safety and complications. Full communication and evaluation are needed to establish appropriate patients' expectations preoperatively. A "Stepup" treatment strategy will be carried out, including conservative treatment, tympanic membrane surgery, Eustachian tube pharyngeal orifice constriction surgery, Eustachian tube tympanic orifice plug surgery and Eustachian tube muscle surgery, which aims to maintain normal Eustachian tube function and good middle ear ventilation.

Intraindividual variability of the Eustachian tube function: a longitudinal study in a pressure chamber

INTRODUCTION

The Eustachian tube (ET) is essential for fast and direct pressure equalisation between middle ear and ambient pressure. It is not yet known to what extent Eustachian tube function in healthy adults changes in a weekly periodicity due to internal and external factors. This question is particularly interesting with regard to scuba divers among whom there is a need to evaluate intraindividual ET function variability.

METHODS

Continuous impedance measurement in a pressure chamber was performed three times at one-week intervals between measurements. Twenty healthy participants (40 ears) were enrolled. Using a monoplace hyperbaric chamber, individual subjects were exposed to a standardised pressure profile consisting of a 20 kPa decompression over 1 min, a 40 kPa compression over 2 min, and a 20 kPa decompression over 1 min. Measurements of Eustachian tube opening pressure (ETOP), opening duration (ETOD), and opening frequency (ETOF) were made. Intraindividual variability was assessed.

RESULTS

Mean ETOD during compression (actively induced pressure equalisation) on the right side was 273.8 (SD 158.8) ms, 259.4 (157.7) ms, and 249.2 (154.1) ms (Chi-square 7.30, P = 0.026) across weeks 1-3. Mean ETOD for both sides was 265.6 (153.3) ms, 256.1 (154.6) ms, and 245.7 (147.8) ms (Chi-square 10.00, P = 0.007) across weeks 1-3. There were no other significant differences in ETOD, ETOP and ETOF across the three weekly measurements.

CONCLUSIONS

This longitudinal study suggests low week-to-week intraindividual variability of Eustachian tube function.

Three-dimensional volumetric analyses of temporal bone pneumatization from early childhood to early adulthood in a South African population

BACKGROUND

A debate exists on whether the size of temporal bone pneumatization is a cause or consequence of otitis media (a global disease burden). However, a normal middle-ear mucosa is a prerequisite for normal temporal bone pneumatization. This study investigated the size of temporal bone pneumatization with age and the normal distribution of air cell volume in different stages of human growth postnatally.

MATERIALS AND METHODS

A three-dimensional computer-based volumetric-rendering technique was performed bilaterally on 248 head/brain and internal acoustic meatus computed tomography images of slice thickness ≤ 0.6 mm consisting of 133 males and 115 females with age range 0-35 years.

RESULTS

The average volume of infant (0-2 years) pneumatization was 1920 mm3 with an expected rapid increase to about 4510 mm3 in childhood (6-9 years). The result also showed a significant increase (p < 0.001) in the volume of air cells up to the young adult stage I (19-25 years), followed by a significant decline in young adult stage II (26-35 years). However, the females were observed to experience an earlier increase than males. Also, population differences were observed as the Black South African population group showed a higher increase in volume with age than the White and Indian South African population groups, though the volumes of the latter increased up to young adult stage II.

CONCLUSIONS

This study concludes that the pneumatization of a healthy temporal bone is expected to continue a linear increase up until at least adult stage I. Termination of temporal bone pneumatization in an individual before this stage could signify pathologic involvement of the middle ear during childhood.

Epigenetic Regulation as a New Therapeutic Target for Middle Ear Cholesteatoma

HYPOTHESIS

To evaluate the effectiveness of the menin-MLL inhibitor, MI503, as a conservative treatment of middle ear cholesteatoma (cholesteatoma) in a mouse model and to confirm its safety profile regarding auditory function in vivo.

BACKGROUND

Cholesteatoma is a mass formed by the keratinizing squamous epithelium in the tympanic cavity and/or mastoid and subepithelial connective tissue and by the progressive accumulation of keratin debris with/without a surrounding inflammatory reaction. Although the main treatment is surgical therapy, the techniques to prevent recurrence remain a critical area of research. Recently, the use of MI503 in experiments resulted in the inhibition of the growth of cholesteatoma in vivo under histone modification.

METHODS

After cholesteatoma was induced in ICR mice (n = 7) by keratinocyte growth factor expression vector transfection, MI503 (50 μM) or phosphate-buffered saline was topically injected for 14 days. The effects of MI503 against cholesteatoma were analyzed by micro-computed tomography images. For the in vivo ototoxicity study, a single intratympanic injection of MI503 (50 or 500 μM) or phosphate-buffered saline (n = 4 each) was done in the ICR mice. An auditory brainstem response was performed at days 0, 1, and 14. For morphological analysis, immunostaining for Phalloidin/F-actin and Myo7a was performed.

RESULTS

MI503 reduced keratinocyte growth factor-induced cholesteatoma in vivo (4 of 4 [100%]). No difference was found in the mean variation of the average of the auditory brainstem response thresholds between the three groups in the in vivo ototoxicity study, thus confirming its safety profile regarding auditory function. MI503 does not demonstrate any deleterious effects on murine hair cells when assessed by immunostaining.

CONCLUSION

These findings demonstrate an encouraging safety profile for the use of menin-MLL inhibitor for the conservative treatment of cholesteatoma.

[Anomalous bony portion of the Eustachian tube]

Reports of congenital anomalies of the Eustachian tube are scare. These anomalies are usually associated with chromosomal abnormalities, most often in oculoauriculovertebral spectrum. We present a case of completely bony widened Eustachian tube, entering the cells of sphenoid sinus lateral recess. No wall defect between the sphenoid sinus and the tube was found, nevertheless the tube and middle ear had normal pneumatisation. The anatomy of the outer ear, otoscopy and hearing thresholds were normal on the ipsilateral side. At the same time, there were microtia, atresia of the external auditory canal, underdeveloped tympanic cavity and cochlea hypoplasia and deafness on the contralateral side, although the majority of previous published cases described ipsilateral temporal bone anomalies. The patient had no facial asymmetry and was not given a syndrome diagnosis.

The middle ear muscle reflex: Current and future role in assessing noise-induced cochlear damage

The middle ear muscle reflex (MEMR) in humans is a bilateral contraction of the middle ear stapedial muscle in response to moderate-to-high intensity acoustic stimuli. Clinically, MEMR thresholds have been used for differential diagnosis of otopathologies for decades. More recently, changes in MEMR amplitude or threshold have been proposed as an assessment for noise-induced synaptopathy, a subclinical form of cochlear damage characterized by suprathreshold hearing problems that occur as a function of inner hair cell (IHC) synaptic loss, including hearing-in-noise deficits, tinnitus, and hyperacusis. In animal models, changes in wideband MEMR immittance have been correlated with noise-induced synaptopathy; however, studies in humans have shown more varied results. The discrepancies observed across studies could reflect the heterogeneity of synaptopathy in humans more than the effects of parametric differences or relative sensitivity of the measurement. Whereas the etiology and degree of synaptopathy can be carefully controlled in animal models, synaptopathy in humans likely stems from multiple etiologies and thus can vary greatly across the population. Here, we explore the evolving research evidence of the MEMR response in relation to subclinical noise-induced cochlear damage and the MEMR as an early correlate of suprathreshold deficits.

[Choristoma of the middle ear]

Choristoma is one of the varieties of congenital developmental anomalies, where one or another normal tissue of the body is located in an atypical place for itself. The short literary review of choristoma of middle ear is presented in article. A rare clinical cases of salivary gland choristoma of the middle ear (5-year-old girl with left-sided conductive hearing loss of III degree) and glial choristoma of the mastoid (19-year-old man with signs of chronic suppurative otitis media of the right ear) are described.

Epidemiology of Eustachian tube dysfunction and related otologic diagnoses among children with achondroplasia

OBJECTIVE

To investigate the prevalence of diagnosed Eustachian tube dysfunction and related otologic diagnoses among children with achondroplasia as compared to a control population.

METHODS

The TriNetX Analytics Network, a federated health research network that aggregates the de-identified electronic health record data of over 78 million patients across the United States, was queried for patients 18 years old or younger with achondroplasia. Patients in this group with any occurrence of diagnosed Eustachian tube dysfunction or specified otologic diagnoses were recorded and reported.

RESULTS

Out of 2,195 patients 18 years old or younger with diagnosed achondroplasia, 379 (17.27%, 95% CI: 15.71-18.91) had a diagnosis of Eustachian tube dysfunction with an 8.65 (95% CI: 7.89-9.48) times higher risk than children without achondroplasia (n = 12,818,655). Children with achondroplasia also had higher risks for diagnosed otitis media (RR: 2.21), tympanic membrane retraction (RR: 7.29), middle ear cholesteatoma (RR: 6.35), cleft palate (RR: 12.24), conductive hearing loss (RR: 12.15), and tympanostomy tube placement (RR: 9.71). Each increased risk was maintained when cleft palate patients were removed from the achondroplasia group.

CONCLUSION

Children with achondroplasia are at a significantly higher risk for diagnosed Eustachian tube dysfunction and related middle ear diagnoses. Atypical craniofacial anatomy among children with achondroplasia may play a role in the dysfunction of the Eustachian tube and thus the observed epidemiology of otologic conditions. Children with achondroplasia should be monitored closely for middle ear conditions and the constellation of symptoms related to a dysfunctional Eustachian tube.

Comparison of an Implantable Middle Ear Microphone and Conventional External Microphone for Cochlear Implants: A Clinical Feasibility Study

OBJECTIVES

All commercially available cochlear implant (CI) systems use an external microphone and sound processor; however, external equipment carries lifestyle limitations. Although totally implantable devices using subcutaneous microphones have been developed, these are compromised by problems with soft tissue sound attenuation, feedback, and intrusive body noise. This in vivo pilot study evaluates a middle ear microphone (MEM) that aims to overcome these issues and compares hearing performance with that of an external CI microphone.

DESIGN

Six adult participants with an existing CI were implanted with a temporary MEM in the contralateral ear. Signals from the MEM were routed via a percutaneous plug and cable to the CI sound processor. Testing was performed in the CI microphone and MEM conditions using a range of audiometric assessments, which were repeated across four visits.

RESULTS

Performance of the MEM did not differ significantly from that of the CI on the assessments of Auditory Speech Sounds Evaluation loudness scaling at either 250 or 1000 Hz, or in the accuracy of repeating keywords presented at 70 dB. However, the MEM had significantly poorer aided sound-field thresholds, particularly at higher frequencies (≥4000 Hz), and significantly poorer performance on Arthur Boothroyd words presented at 55 dB, compared with the CI.

CONCLUSION

In this pilot study, the MEM showed comparable performance to that of an external CI microphone across some audiometric assessments. However, performance with the MEM was poorer than the CI in soft-level speech (55 dB) and at higher frequencies. As such, the benefits of MEM need to be considered against the compromises in hearing performance. However, with future development, MEM is a potentially promising technology.

Air spaces of the temporal bone: a morphometric analysis with clinical implications

BACKGROUND

The main objective of the present study was to analyse the morphological variations of the air spaces of the temporal bone, that is, the pneumatized and air-filled spaces of the temporal bone cavities.

MATERIALS AND METHODS

A total of 99 sides were analysed. Temporal bone pneumatic spaces (TBPS) were defined as the free spaces inside the cavities of the temporal bone filled with air, excluding the volume of the structures present in the investigated region. Total volumes of TBPS were calculated as the sum of total volumes of mastoid air cells (MAC), tympanic cavity (TC), and external auditory canal (EAC). Analyses were performed considering the general population and the female and male subgroups.

RESULTS

The overall results obtained on Polish population were set as follows: the median total volume of TBPS was demonstrated at 7882.58 mm3 (lower quartile [LQ]: 6200.56 mm3; higher quartile [HQ]: 10393.16 mm3). The median volume of MAC was set at 5813.05 mm3 (LQ: 4224.94 mm3; HQ: 8181.81 mm3). The median of the total volume of the EAC was demonstrated at 1294.36 mm3 (LQ: 1099.68 mm3; HQ: 1627.84 mm3).

CONCLUSIONS

In the present study, the morphometric properties of the temporal bone cavities were analysed. The results showed that the total volume of the MAC was, on average, lower in women than in men. This should be taken into account when performing procedures on the mastoid, such as mastoidectomies. It is hoped that the results of this study can help reduce potential surgical complications associated with otological procedures.

Stimulus-frequency otoacoustic emissions and middle-ear pressure gains in a finite-element mouse model

For evoked otoacoustic emissions (OAEs), the stimulus and emission signals traverse the middle ear (ME) in forward and reverse directions, respectively. In this study, a fully coupled three-dimensional finite-element model of the mouse ear canal (EC), ME, and cochlea was used to calculate ME pressure gains, impedances, and reflectances at the EC-entrance and stapes-footplate-cochlear-fluid interfaces. The cochlear model incorporates a series of interdigitated Y-shaped structures sandwiched between the basilar membrane and reticular lamina, each comprised of a Deiters' cell, its phalangeal-process extension, and an outer hair cell (OHC). By introducing random perturbations to the OHC gains, stimulation-frequency otoacoustic emissions (SFOAEs) were generated. Raising the perturbation magnitude from 10% to 80% increased the SFOAE magnitude by up to 24 dB in the 10-30 kHz frequency range. Increasing or decreasing the stiffness of the stapes annular ligament and eardrum by a factor of 8 changed the SFOAEs by up to 30 dB, but the round-trip ME gain as measured could not account for this. A modified round-trip ME gain, with reflections removed at the EC-entrance and stapes-cochlea boundaries, eliminated a ±10 dB discrepancy and allowed ME changes to be quantitatively associated with changes in measured OAEs.

External and middle ear influence on envelope following responses

Considerable between-subject variability in envelope following response (EFR) amplitude limits its clinical translation. Based on a pattern of lower amplitude and larger variability in the low (<1.2 kHz) and high (>8 kHz), relative to mid (1-3 kHz) frequency carriers, we hypothesized that the between-subject variability in external and middle ear (EM) contribute to between-subject variability in EFR amplitude. It is predicted that equalizing the stimulus reaching the cochlea by accounting for EM differences using forward pressure level (FPL) calibration would at least partially improve response amplitude and reduce between-subject variability. In 21 young normal hearing adults, EFRs of four modulation rates (91, 96, 101, and 106 Hz) were measured concurrently from four frequency bands [low (0.091-1.2 kHz), mid (1-3 kHz), high (4-5.4 kHz), and very high (vHigh; 8-9.4 kHz)], respectively, with 12 harmonics each. The results indicate that FPL calibration in-ear and in a coupler leads to larger EFR amplitudes in the low and vHigh frequency bands relative to conventional coupler root-mean-square calibration. However, improvement in variability was modest with FPL calibration. This lack of a statistically significant improvement in variability suggests that the dominant source of variability in EFR amplitude may arise from cochlear and/or neural processing.

Exploring the middle ear function in patients with a cluster of symptoms including tinnitus, hyperacusis, ear fullness and/or pain

Middle ear muscle (MEM) abnormalities have been proposed to be involved in the development of ear-related symptoms such as tinnitus, hyperacusis, ear fullness, dizziness and/or otalgia. This cluster of symptoms have been called the Tonic Tensor Tympani Syndrome (TTTS) because of the supposed involvement of the tensor tympani muscle (TTM). However, the putative link between MEM dysfunction and the symptoms has not been proven yet and the detailed mechanisms (the causal chain) of TTTS are still elusive. It has been speculated that sudden loud sound (acoustic shock) may impair the functioning of the MEM, specifically the TTM, after an excessive contraction. This would result in inflammatory processes, activation of the trigeminal nerve and a change of the MEMs state into a hypersensitive one, that may be associated to the cluster of symptoms listed above. The goal of this study is to provide further insights into the mechanisms of TTTS. The middle ear function of 11 patients who reported TTTS symptoms has been investigated using either admittancemetry and/or measurement of air pressure in the sealed external auditory canal. While the former method measured the middle ear stiffness the latter provides an estimate of the tympanic membrane displacement. Most patients displayed results consistent with phasic contractions of the TTM (n = 9) and/or Eustachian Tube (ET) dysfunction (n = 6). The MEM contraction or ET dysfunction could be evoked by acoustic stimulation (n = 3), somatic maneuvers (n = 3), or pressure changes in the ear canal (n = 3). Spontaneous TTM contraction (n = 1) or ET opening (n = 1) could also be observed. Finally, voluntary contraction of MEM was also reported (n = 5). On the other hand, tonic contraction of the TTM could not be observed in any patient. The implications of these results for the mechanisms of TTTS are discussed.

[Correlation between acoustic immittance and ETS in eustachian tube function test]

Objective:To investigate the correlation between acoustic immittance and eustachian tube score（ETS） in eustachian tube function test. Methods:124 ears eustachian tube function with tympanic tension perforation of 107 patients with chronic suppurative otitis media were measured by acoustic immittance positive pressure balance method and ETS. According to the positive pressure balance test results of acoustic immittance, the ear eustachian tube open pressure between 100 and 200 daPa is assigned 2, the ear with open pressure between 200 and 300 daPa is assigned 3, the ear with open pressure betwween 300 and 400 daPa is assigned 4, the ear open pressure is greater than 400 daPa but eustachian tube open after swallowing is assigned 5, and the ear which eustachian tube open pressure is greater than 400 daPa and cannot open after swallowing is assigned 6. Then compare the results. Results:In the acoustic immittance test, there was no ears whose eustachian tube opening pressure less than 100 daPa, 10 ears（8.1%） open pressure between 100 and 200 daPa, 16 ears（12.9%） open pressure between 200 and 300 daPa, 46 ears（37.1%） open pressure between 300 and 400 daPa, 19 ears（15.3%） whose eustachian tube don't open pressure at 400 daPa but open after swallowing, and the cumulative percentage of the above was 73.4%. There were 33 ears（26.6%） whose eustachian tubes not opening after receiving maximum pressure（400 daPa） and repeated swallowing. The score of acoustic immittance eustachian tube function test was significantly correlated with the scores of ETS, eustachian tube manometry（TMM） and subjective part of ETS（P<0.05）. The result of acoustic immittance was moderately negatively correlated with ETS（r=-0.439） and TMM（r=-0.425）, and weakly negatively correlated with subjective part of ETS（r=-0.249）. The scores of 2-5 points （the affected ears with open eustachian tube in all acoustic impedance test methods） were defined as the normal group, and the scores of 6 point were defined as the abnormal group. The results of acoustic immittance between the normal group and the abnormal group showed that there were significant differences with the subjective scores of ETS, TMM and ETS. The consistency compared the results of acoustic immittance eustachian tube test with the results of ETS was poor（kappa value was negative）, and the difference was statistically significant. Conclusion:The open pressure of acoustic immittance positive pressure balance method is a good predictor of the subjective scores of ETS, TMM and ETS. The smaller the open pressure is, the better the subjective scores of ETS, TMM and ETS may be. This two methods results are inconsistent and cannot be replaced. More consideration should be given to the middle ear. The open pressure, equilibrium pressure and the difference between them need to be paid attention to at the same time.

Efficacy of Mesotympanum Injection and Posterior Auricular Injection in Sudden Hearing Loss of Diabetes Patients

The efficacy of tympanum injection and posterior auricular injection in diabetes with sudden hearing loss (SHL) was analyzed. A mobile terminal-based portable pure tone audiometry system and its processing method were established. Based on mobile terminals, a portable pure tone audiometry system including an Android system, pure sound signal generation, pure tone hearing threshold, and client module was established. A masking model and self-adaptive algorithm were used to detect and reduce noise. Besides, the performance of the portable pure tone audiometry system was detected. A total of 46 diabetes patients with SHL diagnosed at the otolaryngology department in BeiChen Hospital between August 2019 and November 2021 were selected as the research objects and randomly divided into the retroauricular group (posterior auricular injection) and the tympanic group (tympanum injection). Each group included 23 cases. All patients received pure tone audiometry (PTA) before and after the treatment. The changes in fasting blood glucose (FPG), 2h postprandial blood glucose (2hPG), and glycosylated hemoglobin (HbA1c) of the patients were monitored before and after the treatment. Besides, tinnitus loudness visual analog scale (VAS), pain VAS, efficacy, and the incidence of adverse reactions of the patients in two groups were compared. The results indicated that the hear threshold error detected by the medical audiometer and a portable pure tone audiometry system was within 2dB. Before the optimization, there was an error of about 10dB between the hear thresholds detected by the self-adaptive algorithm and a medical audiometer. After the treatment, the hear threshold and average PTA of the patients in the retroauricular and the tympanic groups under different frequencies were both reduced compared with those before the treatment (P < 0.05). The tinnitus VAS score in the retroauricular group was decreased more notably than that in tympanic group (P < 0.01), and the pain VAS score was much lower than that in the tympanic group (P < 0.001). The comparison of FPG, 2hPG, HbA1c, the proportions of cured, significantly effective, effective, ineffective patients, and the total effective rate in the patients in the retroauricular and the tympanic groups before and after the treatment all showed no statistical differences (P > 0.05). The incidence of adverse reactions in tympanic group after the treatment was dramatically higher than that in retroauricular group (P < 0.001). The above results demonstrated that posterior auricular injection showed potential application values in the treatment of SHL with diabetes and established a portable pure tone audiometry system as well as its noise processing method.

Water protection in paediatric patients with ventilation tubes: Myth or reality? A systematic review

BACKGROUND

Myringotomy with ventilation tube (VT) insertion is one the most performed procedures in children and adolescents worldwide. VTs usually remain in the eardrum between 6 and 12 months and during this period otorrhoea is the most frequent complication. For years, parents have been advised to protect the ears of children with VTs from contact with water, as water exposure in the middle ear is likely to cause acute otitis media. However, there is a growing evidence that water should not traverse VTs unless under significant pressure, so routine water precautions should not be prescribed. Despite these recommendations, many otolaryngologists and paediatricians continue to prescribe earplugs during bathing or swimming or advise against aquatic activities. There are already two reviews in the current literature on this topic: the first used strict selection criteria and included only 2 high-quality studies, while the second presented evidence up to 2005. The aim of this review is to identify, summarize and critically appraise the current evidence concerning water precautions for children with VTs.

METHODS

Two independent reviewers separately searched for related scientific papers. A qualitative synthesis analysis was performed considering the selected studies regarding the effects of water exposure on paediatric subjects with VTs.

RESULTS

Four randomized clinical trials (RCT) and five prospective cohort studies were included, for a total of 1299 patients aged from 3 months to 14 years. No statistically significant difference in otorrhoea incidence between water exposure with and without ear protection in children with VTs, and between water exposure and no water exposure in children with VTs, was found. Therefore avoiding water is at best inconvenient and at worst may delay learning to swim. The decision to protect the ear when exposed to water should be individualized and protection should be recommended during the first month after surgery and in cases of recurrent otorrhoea.

CONCLUSION

Based on the literature available, allowing water surface activities with no ear protection seems to present a minimum risk, so it is not necessary to prohibit patients from swimming. However, some recommendations should be followed.

History of nasopharyngeal study: A 5,000-year odyssey into our evolving understanding of a small but vital region

The nasopharynx has been understudied relative to neighboring anatomical regions. It is a highly complex, integrated space whose function, development, and evolution remains unclear after nearly 5,000 years of study. Historically, most work on the nasopharynx was done with a focus on adjacent structures. It has most often been mentioned in relation to the middle ear (via the Eustachian tube) in ancient texts and has only later been given a designation as one of three portions of a tripartite pharynx among adult humans. As human dissection became practiced more widely in Renaissance Europe, understanding of the nasopharyngeal boundaries improved. With further advancements in the study of nasopharyngeal development, evolution, and anatomical variation from the 19th century up until the present, this region has been shown to be functionally vital and still complicated to define.

Possible Neoplastic or Proliferative Effects of Intra-Tympanic Platelet-Rich Plasma on the MiddleEarMucosa: A Myth or a Fact to Consider?

BACKGROUND

Platelet-rich plasma is a frequently used plasma-derived material; however, a possible neoplastic or proliferative effect is one of the limiting issues in its use. The aim of our experimental study was to investigate the long-term histological effects of platelet-rich plasma on the middle ear mucosa.

METHODS

The rats were divided into 2 groups randomly (groups 1 and 2). Group 1 represented the control group and 8 rats were included in this group. To the left ear, 0.3 mL of normal saline solution was administered intra-tympanically. No injections were done to the right ears. Group 2 represented the platelet-rich plasma group and 11 rats were included. To the left ears, 0.3 mL of platelet-rich plasma and to the right ears 0.3 mL of normal saline solution was administered intra-tympanically. The intra-tympanic platelet-rich plasma injections were done twice with an interval of 1 week. All animals were sacrificed in the third month. The degree of mucosal thickness, the presence of metaplasia, atypical cells, myofibroblastic infiltration, angiogenesis, and acute or chronic inflammation were evaluated histopathologically.

RESULTS

Histopathological findings in the right and left ears in each group were compared in itself. The degree of inflammation and mucosal thickness were significantly higher in the perforated and saline administered side, in group 1 (P < .001). In group 2, the degree of angiogenesis was significantly higher in the platelet-rich plasma administered side (P < .001). The degree of mucosal thickness was significantly higher in the saline administered side (P < .001).

CONCLUSION

Considering the anti-inflammatory and regenerative features and its safety, intra-tympanic-PRP may, in the future, be an alterna- tive to current intra-tympanic treatment modalities.

Automated Adaptive Wideband Acoustic Reflex Threshold Estimation in Normal-hearing Adults

OBJECTIVES

Acoustic stapedius reflex threshold (ART) tests are included in a standard clinical acoustic immittance test battery as an objective cross-check with behavioral results and to help identify site of lesion. In traditional clinical test batteries, middle-ear admittance of a 226 Hz probe is estimated using ear-canal measurements in the presence of a reflex-activating stimulus. In the wideband (WB) acoustic immittance ART test used in this study, the pure-tone probe is replaced by a WB probe stimulus and changes in absorbed power are estimated using ear-canal measurements in the presence of the activator. The ART is defined as the lowest level at which a criterion change in admittance (clinical) or absorbed power (WB) is observed in the presence of the activator. In the present study, ARTs were obtained in adults with normal hearing using the clinical, manual method and with a new WB automated adaptive threshold detection method. It was hypothesized that the WB test would result in lower ARTs than the clinical test because reflex-related changes in power absorbance could be observed across multiple frequency bands in the WB test compared with a single frequency in the traditional test.

DESIGN

Data were collected in a prospective research design. ARTs were obtained in ipsilateral and contralateral conditions using 500, 1000, 2000 Hz, and broadband noise (BBN) activators on a clinical system and on an experimental WB system. The bandwidth of the BBN activator was 125 to 4000 Hz on the clinical system and 200 to 8000 Hz on the wideband system. ARTs were estimated at both tympanometric peak pressure (TPP) and ambient pressure on the WB system. Data were collected in both ears of 39 adults (21 males) of mean age 47.7 years (range 23-72 years). Differences in ARTs among the three threshold estimation methods (clinical, WB at TPP, WB at ambient) were examined using the general linear model repeated measures test in SPSS. Post-hoc pairwise comparisons were completed with Bonferroni correction for multiple comparisons. Statistical significance was defined as p < 0.05 for all analyses.

RESULTS

ARTs obtained on the WB system at TPP and ambient pressure were significantly lower than obtained on the clinical system. ARTs obtained on the WB system at TPP were significantly higher than at ambient pressure in the 500 and 2000 Hz ipsilateral conditions.

CONCLUSIONS

WB automated adaptive ARTs in normal-hearing adults were lower than for clinical methods when measured at TPP and ambient pressure. Lower presentation levels required to estimate ART in the WB test may be more tolerable to patients. Patients with ARTs that are not present at the maximum level of a traditional reflex test may have present ARTs with a WB ART test, which may reduce the need to refer for additional testing for possible retrocochlear involvement. Automation of the test may allow clinicians more time to attend to the other requisite tasks of a hearing evaluation and make the system useful for telehealth applications.

Persisting variance in middle ear ventilation tube insertion in Auckland children: why ethnic disparity continues

AIM

Insertion of ventilation tubes (VTs) is a common surgical treatment for recurrent and persistent otitis media, but surgical practice varies internationally. The current study explored variations in practice within New Zealand by examining VT insertion rates. The aim of the study was to determine time trends and current variations in VT insertion rates by ethnicity and district health board (DHB), with a focus on comparison of two DHBs in Auckland (Counties Manukau and Auckland DHB) to national average data.

METHOD

Data for surgical procedures were analysed in the Atlas of Healthcare Variation domain, available via the Health Quality & Safety Commission website. Publicly funded events for New Zealand residents over a 10-year period (2009-2018) were examined for 0-4-year-olds. Individuals were assigned to their DHB of residence. VT rates for each DHB are presented per 1,000 population, with upper and lower confidence intervals calculated to the 95% level.

RESULTS

There was a general decline in the rates of VT insertions for the 0-4-year-olds over the 2009-2018 decade. Analysis of the 2018 year showed variation by ethnicity and DHB. In CMDHB, ADHB and nationally, Asian and Pacific ethnic groups had the lowest rates of VT insertions compared to other ethnic groups. In CMDHB, the VT rates for Māori, Pacific and Asian children were less than half that of their respective groups in ADHB. The NZ European/Other ethnic group had the highest rates of VT insertions in CMDHB and nationally, but in ADHB, the rate for the NZ European/Other group was similar to that for Māori.

CONCLUSION

These results are incongruent with evidence that Māori and Pacific children in New Zealand experience a greater burden of middle ear disease than NZ European children. The finding of persisting inequities in VT treatment for middle ear disease in 0-4-year-olds, with greatest impact on Pacific children, suggests that there may be a need for targeted middle ear screening for preschool children to detect pre-schoolers with ear disease, earlier than the 4-year-old B4 School Check.

[Numerical simulation modeling of middle ear-eustachian tube ventilation based on Chinese digital visual human body]

Objective: To establish a three-dimensional model of middle ear-eustachian tube based on Chinese digital visual human dataset, and the deformation and pressure changes of the middle ear-eustachian tube system after eustachian tube opening are simulated by computer numerical simulation. Methods: The first female Chinese Digital Visual Human data was adopted. The images were imported by Amira image processing software, and the images were segmented by Geomagic software to form a three-dimensional model of middle ear-eustachian tube system, including eustachian tube, tympanum, tympanic membrane, auditory ossicles, and mastoid air cells system. The 3D model was imported into Hypermesh software for meshing and analysis. The structural mechanics calculation was carried out by Abaqus, and gas flow was simulated by Xflow. The tissue deformation and middle ear pressure changes during eustachian tube opening were numerically simulated by fluid-solid coupling algorithm. Several pressure monitoring points including tympanum, mastoid, tympanic isthmus, and external auditory canal were set up in the model, and the pressure changes of each monitoring point were recorded and compared. Results: In this study, a three-dimensional model of middle ear-eustachian tube and a numerical simulation model of middle ear ventilation were established, including eustachian tube, tympanum, mastoid air cells, tympanic membrane, and auditory ossicles. The dynamic changes of the model after ventilation could be divided into five stages according to the pressure. In addition, the pressure changes of tympanum and tympanic isthmus were basically synchronous, and the pressure changes of mastoid air cells system were later than that of tympanum and tympanic isthmus, which verified the pressure buffering effect of mastoid. The extracted pressure curve of the external auditory canal was basically consistent with that of tympanometry in terms of value and trend, which verified the effectiveness of the model. Conclusions: The numerical simulation model of middle ear-eustachian tube ventilation established in this paper can simulate the tissue deformation and middle ear pressure changes after eustachian tube opening, and its accuracy and effectiveness are also verified. This not only lays a foundation for further research, but also provides a new research method for the study of middle ear ventilation.

gom1 Mutant Mice as a Model of Otitis Media

Otitis media (OM) disease is a common cause of hearing loss that is primarily the result of middle ear infection. At present, our understanding of the mechanisms leading to OM is limited due to the lack of animal models of OM with effusion (OME). Here, we report that the mice with genetic otitis media one (gom1) mutants are prone to OM. gom1 Mice were produced by the N-ethyl-N-nitrosourea (ENU) mutagenesis program as an animal model to study OM. These mice demonstrate many common features of OM, such as middle ear effusion and hearing impairment. We revealed that gom1 mice display various signs of middle ear and inner ear dysfunctions, including elevated thresholds of auditory-evoked brainstem response (ABR) and lack of cochlear microphonic responses. Decreased compliance in tympanometry measurements indicates tympanic membrane and ossicular chain malfunction. We confirmed through histological examinations of middle ear structures that 34/34 (100 %) of the mutant mice suffered from severe OME. While individual ears had different levels of effusion and inflammatory cells in the middle ear cavity, all had thickened middle ear mucosa and submucosa compared to control mice (B6). Moreover, the mutant mice displayed cochlear hair cell loss. These observations also suggested the craniofacial abnormalities in the gom1 mouse model. Together, these results indicate that gom1 mice could be valuable for investigating the genetic contribution to the development of middle ear disease.

The Impacts of Noise Exposure on the Middle Ear Muscle Reflex in a Veteran Population

PURPOSE

Human studies of noise-induced cochlear synaptopathy using physiological indicators identified in animal models (auditory brainstem response [ABR] Wave I amplitude, envelope following response [EFR], and middle ear muscle reflex [MEMR]) have yielded mixed findings. Differences in the population studied may have contributed to the differing results. For example, due to differences in the intensity level of the noise exposure, noise-induced synaptopathy may be easier to detect in a military Veteran population than in populations with recreational noise exposure. We previously demonstrated a reduction in ABR Wave I amplitude and EFR magnitude for young Veterans with normal audiograms reporting high levels of noise exposure compared to non-Veteran controls. In this article, we expand on the previous analysis in the same population to determine if MEMR magnitude is similarly reduced.

METHOD

Contralateral MEMR growth functions were obtained in 92 young Veterans and non-Veterans with normal audiograms, and the relationship between noise exposure history and MEMR magnitude was assessed. Associations between MEMR magnitude and distortion product otoacoustic emission, EFR, and ABR measurements collected in the same sample were also evaluated.

RESULTS

The results of the statistical analysis, although not conventionally statistically significant, suggest a reduction in mean MEMR magnitude for Veterans reporting high noise exposure compared with non-Veteran controls. In addition, the MEMR appears relatively insensitive to subclinical outer hair cell dysfunction, as measured by distortion product otoacoustic emissions, and is not well correlated with ABR and EFR measurements.

CONCLUSIONS

When combined with our previous ABR and EFR findings in the same population, these results suggest that noise-induced synaptopathy occurs in humans. In addition, the findings indicate that the MEMR may be a good candidate for noninvasive diagnosis of cochlear synaptopathy/deafferentation and that the MEMR may reflect the integrity of different neural populations than the ABR and EFR.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.18665645.