Comparison of wideband acoustic immittance in Chinese infants under three months of age with normal and abnormal middle ear function

OBJECTIVES

This study aims to compare the characteristics of Wideband Acoustic Immittance (WAI) in Chinese infants under three months of age, with either normal or abnormal middle ear function.

METHODS

We recruited 98 infants with either normal or abnormal middle ear function, and subsequently divided them into four groups based on their middle ear function and chronological age. The absorbances at tympanometric peak pressure (TPP) were collected across 1/3rd octave frequencies ranging from 226 to 8000 Hz.

RESULTS

Among infants with normal middle ear function, no significant differences were observed concerning ear laterality. However, significant differences were noted at 3364 Hz and 4000 Hz with respect to age. For infants with either normal or abnormal middle ear function, we found significant differences at the majority of frequencies. Additionally, the receiver operating characteristic (ROC) curves and maxima Youden index indicated that absorbances at 1682 Hz and 1297 Hz could be employed to evaluate the middle ear function of infants at 1 and 2 months of age.

CONCLUSION

This study demonstrates that WAI holds promise as a valuable tool for assessing the middle ear condition of infants at 1 and 2 months of age. Infants aged 1 and 2 years, having absorbance values equal to or greater than 0.7470 at 1682 Hz and 0.6775 at 1297 Hz respectively, may indicate normal middle ear function. Furthermore, it underscores the necessity of establishing ethnicity- and age-specific norms for WAI in infants under 3 months of age.

Myringoplasty for pediatric chronic otitis media: An uncritical closure of a natural middle ear drainage?

BACKGROUND

Performing tympanoplasty for tympanic perforations in children and adolescents is often considered to be less successful than in adults.

OBJECTIVES

The aim of our study was to evaluate the surgical outcome of tympanoplasty type I in patients under 15 years of age with chronic otitis media and to identify potential factors that influence the success rate.

MATERIALS UND METHODS

The present study was based on a retrospective analysis of the medical records of all patients under the age of 15 who were treated for chronic otitis media by means of type I tympanoplasty between 2005 and 2020. The minimum follow-up period was 6 months. The data were analyzed with regard to epidemiological parameters, tube-related pathologies in the contralateral ear, the local condition and the extent of the eardrum perforation as well as the extent of the surgical intervention (tympanoplasty type I with or without adenotomy).

RESULTS

83 cases were included in our study. The mean age at the time of the surgery was 8.9 years. The mean follow-up time was 46 months (6-182 months). The anatomical closure rate was 88.0%. Children with "dry" tympanic perforations tended to perform better (p = 0.052). The average improvement in the air bone gap was 2.0 dB.

CONCLUSION

Detailed preoperative counseling about the advantages and disadvantages as well as the expected success rate of an early myringoplasty in this age group is just as important as an individualized approach for a high level of patient satisfaction.

Can the negative pressures found in obstructive sleep apnea and Eustachian tube dysfunction be related?

OBJECTIVE

The association between obstructive sleep apnea (OSA) and Eustachian tube dysfunction (ETD) is well known. When both exist in a single pediatric patient, one of the expected culprits is adenoid enlargement. We hypothesize, in contrast, that the negative pharyngeal pressure found in OSA may be transmitted to the middle ear as negative middle ear pressure (MEP), which subsequently results in pathology. The objective of this study was to determine whether the degree of OSA and MEP are associated while using MEP as a quantifiable measurement of ETD.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic center (Jan 2000-Jan 2018).

SUBJECTS AND METHODS

The relationship between apnea-hypopnea index (AHI) and MEP was examined. A non-anatomic model was utilized to support causality.

RESULTS

Thirty-four pediatric patients and twenty-three adult patients were included in the analysis. REM AHI showed a moderate negative correlation with MEP in children (r = -0.265), and a weak positive correlation with MEP in adults (r = 0.171). Children with an AHI in the severe OSA category had a more negative mean MEP than those in the mild category (p = 0.36). Adults with an AHI in the severe OSA category had a more positive mean MEP than those in the mild category (p = 0.11).

CONCLUSION

In children, increasing severity of OSA is associated with a negative MEP, suggesting that negative pressure associated with OSA may be transmitted to the middle ear. In adults, increasing severity of OSA is associated with a more positive MEP.

Bone-conduction threshold and air-bone gap may predict frequency-specific air-conduction threshold after tympanoplasty

Postoperative hearing improvement is one of the main expectations for patients receiving tympanoplasty. The capacity to predict postoperative hearing may help to counsel a patient properly and avoid untoward expectations. It is difficult to predict postoperative hearing without knowing the disease process in the middle ear, which can only be assessed intraoperatively. However, the duration and extent of the underlying pathologies may represent in bone-conduction threshold and air-bone gap. Here in patients undergoing tympanoplasty without ossiculoplasty, we sorted and separated the surgery dates into the first group to build the predicting models and the second group to test the predictions. There were 87 and 30 ears, respectively. No specific enrollment or exclusion criteria were based on underlying pathologies such as the perforation size of the tympanic membrane or the middle ear conditions. The results show that bone-conduction threshold and air-bone gap together predicted air-conduction threshold after the surgery, including each frequency of 0.5k, 1k, 2k, and 4k Hz. The discrepancies between the predictions and recordings did not differ among these four frequencies. Of the variance in mean postoperative air-conduction threshold, 56.7% was linearly accounted for by these two preoperative predictors in this sample. The results suggest a trend that, the higher the frequency, the larger the part was accounted for by these two preoperative predictors. These together may help a surgeon to estimate frequency-specific hearing outcome after the surgery, answer patients' questions with quantitative statistics, and counsel patients with proper expectations.

STAT1 deficiency predisposes to spontaneous otitis media

Signal transducer and activator of transcription 1 (STAT1) is known to be an important player in inflammatory responses. STAT1 as a transcription factor regulates the expression of multiple proinflammatory genes. Inflammatory response is one of the common effects of ototoxicity. Our group reported that hair cells of STAT1 knockout (STAT1-KO) mice are less sensitive to ototoxic agents in-vitro. The effect of inflammatory responses in STAT1-KO mice has primarily been studied challenging them with several pathogens and analyzing different organs of those mice. However, the effect of STAT1 ablation in the mouse inner ear has not been reported. Therefore, we evaluated the cochlear function of wild type and STAT1-KO mice via auditory brain stem response (ABR) and performed histopathologic analysis of their temporal bones. We found ABR responses were affected in STAT1-KO mice with cases of bilateral and unilateral hearing impairment. Histopathologic examination of the middle and inner ears showed bilateral and unilateral otitis media. Otitis media was characterized by effusion of middle and inner ear that varied between the mice in volume and inflammatory cell content. In addition, the thickness of the middle ear mucosae in STAT1-KO mice were more pronounced than those in wild type mice. The degree of middle and inner ear inflammation correlated with ABR threshold elevation in STAT1-KO mice. It appears that a number of mice with inflammation underwent spontaneous resolution. The ABR thresholds were variable and showed a tendency to increase in homozygous and heterozygous STAT1-KO mice. These findings suggest that STAT1 ablation confers an increased susceptibility to otitis media leading to hearing impairment. Thus, the study supports the new role of STAT1 as otitis media predisposition gene.

Transcanal endoscopic excision of glomus tympanicum: A case report

Glomus tympanicum is a highly vascular tumour traditionally treated surgically via a post-auricular approach. We present here the first published case in Malaysia where total excision was achieved transcanal endoscopically. The procedure was safe, quick and effective due to the better visualisation of the surgical field with the endoscope. Haemostasis was achieved with a modified suction catheter that performed as a functioning suction diathermy.

Limitations of present models of blast-induced sound power conduction through the external and middle ear

The use of models to predict the effect of blast-like impulses on hearing function is an ongoing topic of investigation relevant to hearing protection and hearing-loss prevention in the modern military. The first steps in the hearing process are the collection of sound power from the environment and its conduction through the external and middle ear into the inner ear. Present efforts to quantify the conduction of high-intensity sound power through the auditory periphery depend heavily on modeling. This paper reviews and elaborates on several existing models of the conduction of high-level sound from the environment into the inner ear and discusses the shortcomings of these models. A case is made that any attempt to more accurately define the workings of the middle ear during high-level sound stimulation needs to be based on additional data, some of which has been recently gathered.

The optimal and safe intensity for facial nerve stimulation during intraoperative neuromonitoring in middle ear surgery

Objective

This study aimed to investigate the optimal and safe intensity for facial nerve stimulation during middle ear surgery.

Methods

Thirty-seven patients who had their facial nerve exposed prior to surgery were prospectively enrolled in this study, and electromyography (EMG) recordings were obtained from the orbicularis oculi and orbicularis oris muscles. Four pigs were also enrolled in an animal study, and continuous stimulation was performed on the facial nerves of the pigs for 10 minutes. The EMG responses were measured and the pathologic outcomes of the facial nerve after stimulation were determined.

Results

In the human study, the mean intensity of the minimal electrical stimulation threshold was 0.21 mA (range: 0.1–0.3 mA). A linear correlation was observed between stimulus intensity and response amplitude for intensities below 0.4 mA. Response amplitudes reached a plateau between 0.4 mA and 1.0 mA. The minimal stimulus intensity that could generate a maximal response was 0.4 mA in the orbicularis oculi (244 μV) and orbicularis oris (545 μV). In the animal study, there were no observed changes in EMG or nerve damage incidence after the continuous stimulation of 3.0 mA.

Conclusions

0.4 mA is considered to be the optimal intensity of facial nerve stimulation during middle ear surgery, and it was estimated through the animal study that a stimulation of 3.0 mA is safe from facial nerve damage.

Diagnosing Middle Ear Dysfunction in 10- to 16-Month-Old Infants Using Wideband Absorbance: An Ordinal Prediction Model

Purpose The aim of this study was to develop an ordinal prediction model for diagnosing middle ear dysfunction in 10- to 16-month-old infants using wideband absorbance. Method Wideband absorbance, tympanometry, and distortion product otoacoustic emissions were measured in 358 ears of 186 infants aged 10-16 months (M _age = 12 months). An ordinal reference standard (normal, mild, and severe middle ear dysfunction) was created from the tympanometry and distortion product otoacoustic emission results. Absorbance from 1000 to 5657 Hz was used to model the probability of middle ear dysfunction with ordinal logistic regression. Model performance was evaluated using measures of discrimination (c-index) and calibration (calibration curves). Performance measures were adjusted for overfitting (bias) using bootstrap resampling. Probabilistic and simplified methods for interpreting the model are presented. The probabilistic method displays the probability of ≥ mild and ≥ severe middle ear dysfunction, and the simplified method presents the condition with the highest probability as the most likely diagnosis (normal, mild, or severe middle ear dysfunction). Results The c-index of the fitted model was 0.919 (0.914 after correction for bias), and calibration was satisfactory for both the mild and severe middle ear conditions. The model performed well for the probabilistic method of interpretation, and the simplified (most likely diagnosis) method was accurate for normal and severe cases but diagnosed some cases with mild middle ear dysfunction as normal. Conclusions The model may be clinically useful, and either the probabilistic or simplified paradigm of interpretation could be applied, depending on the context. In situations where the main goal is to identify severe middle ear dysfunction and ease of interpretation is highly valued, the simplified interpretation may be preferable (e.g., in a screening clinic that may not be concerned about missing some mild cases). In a diagnostic clinical environment, however, it may be beneficial to use the probabilistic method of interpretation.

Wideband Tympanmetry Results of Bone Cement Ossiculoplasty

OBJECTIVE

We aim to investigate hearing sensitivity and wideband tympanometry results in bone cement ossiculoplasty cases in present study.

STUDY DESIGN

A prospective study.

SETTING

Ossiculoplasty patients were grouped according to the anatomical location of bone cement application by surgery note. Ossiculoplasty and tympanoplasty patients were retrospectively invited to the clinic and evaluated. 30 bone cement ossiculoplasty cases as well as 30 Type I tympanoplasty cases (intact ossicular chain) and 30 healthy controls were included in the study and Wideband Tympanometry was performed. Tympanometric peak pressure, equivalent middle ear volume, static admittance, tympanogram width, resonance frequency, average wideband tympanometry and absorbance measurements were analyzed.

RESULTS

A statistically significant improvement was observed in the hearing levels of all ossiculoplasty and type I tympanoplasty patients (p < 0.05). Bone cement ossiculoplasty groups demonstrated the remarkable differences than the type I tympanoplasty and control group in Wideband Tympanometry test parameters. In some parameters, malleus-stapes and manubriostapedioplasty groups demonstrated similarities to Type I tympanoplasty and control groups.

CONCLUSION

Bone cement is an effective application for ossiculoplasty. Wideband tympanometry is a promising method for the evaluation of the middle ear dynamics.

Changes in middle ear transmission characteristics secondary to altered bone remodelling

Alteration in the process of bone remodelling results in conditions like osteopenia and osteoporosis in which the bones become susceptible to fracture. The functioning of middle ear bones in such individuals were assessed in this study and it was found that the middle ear bones are equally susceptible to micro-fractures and can cause reduction in the transmission of sound energy.

INTRODUCTION

Alteration in the process of bone remodelling or increase in the number of osteoclasts cells as it occurs in osteoporosis and osteopenia are likely to affect the middle ear bones in the same way it affects the skeletal bones. Whether these micro-structural changes occurring at the level of the middle ear secondary to altered bone remodelling cause any significant impairment in its functioning is not explored. Thus, the present study aimed at assessing the different aspects of middle ear functioning in individuals with reduced BMD.

METHODS

The study included 25 normal, 39 osteopenic and 40 osteoporotic participants. The participants underwent pure-tone audiometry, otoscopic examination, conventional immittance evaluation using a 226 Hz probe tone, multi-component and multi-frequency tympanometry and acoustic reflex threshold testing. None of the participants had any current or previous history of middle ear effusion.

RESULTS

A significantly higher proportion of participants in the clinical group had hearing loss compared to the normal group. The clinical group participants also had reduced middle ear resonance frequency, elevated static compliance values and elevated or absent acoustic reflexes compared to the normal participants. There was no difference among the three groups for the proportion of participants having conductive hearing loss.

CONCLUSIONS

There is a detrimental impact of reduction in bone mineral density on middle ear transmission characteristics which may go unnoticed initially. Treatment of osteoporosis may potentially mitigate hearing loss from middle ear fractures due to reduced bone mineral density. Absence of significant air-bone gap with the presence of reduced middle ear resonance frequency may be early signs of reduced BMD.

Chirp-Evoked Otoacoustic Emissions and Middle Ear Absorbance for Monitoring Ototoxicity in Cystic Fibrosis Patients

OBJECTIVES

The goal of this study was to investigate the use of transient-evoked otoacoustic emissions (TEOAEs) and middle ear absorbance measurements to monitor auditory function in patients with cystic fibrosis (CF) receiving ototoxic medications. TEOAEs were elicited with a chirp stimulus using an extended bandwidth (0.71 to 8 kHz) to measure cochlear function at higher frequencies than traditional TEOAEs. Absorbance over a wide bandwidth (0.25 to 8 kHz) provides information on middle ear function. The combination of these time-efficient measurements has the potential to identify early signs of ototoxic hearing loss.

DESIGN

A longitudinal study design was used to monitor the hearing of 91 patients with CF (median age = 25 years; age range = 15 to 63 years) who received known ototoxic medications (e.g., tobramycin) to prevent or treat bacterial lung infections. Results were compared to 37 normally hearing young adults (median age = 32.5 years; age range = 18 to 65 years) without a history of CF or similar treatments. Clinical testing included 226-Hz tympanometry, pure-tone air-conduction threshold testing from 0.25 to 16 kHz and bone conduction from 0.25 to 4 kHz. Experimental testing included wideband absorbance at ambient and tympanometric peak pressure and TEOAEs in three stimulus conditions: at ambient pressure and at tympanometric peak pressure using a chirp stimulus with constant incident pressure level across frequency and at ambient pressure using a chirp stimulus with constant absorbed sound power across frequency.

RESULTS

At the initial visit, behavioral audiometric results indicated that 76 of the 157 ears (48%) from patients with CF had normal hearing, whereas 81 of these ears (52%) had sensorineural hearing loss for at least one frequency. Seven ears from four patients had a confirmed behavioral change in hearing threshold for ≥3 visits during study participation. Receiver operating characteristic curve analyses demonstrated that all three TEOAE conditions were useful for distinguishing CF ears with normal hearing from ears with sensorineural hearing loss, with an area under the receiver operating characteristic curve values ranging from 0.78 to 0.92 across methods for frequency bands from 2.8 to 8 kHz. Case studies are presented to illustrate the relationship between changes in audiometric thresholds, TEOAEs, and absorbance across study visits. Absorbance measures permitted identification of potential middle ear dysfunction at 5.7 kHz in an ear that exhibited a temporary hearing loss.

CONCLUSIONS

The joint use of TEOAEs and absorbance has the potential to explain fluctuations in audiometric thresholds due to changes in cochlear function, middle ear function, or both. These findings are encouraging for the joint use of TEOAE and wideband absorbance objective tests for monitoring ototoxicity, particularly, in patients who may be too ill for behavioral hearing tests. Additional longitudinal studies are needed in a larger number of CF patients receiving ototoxic drugs to further evaluate the clinical utility of these measures in an ototoxic monitoring program.

A comparison between video otoscopy and standard tympanometry findings in adults living with human immunodeficiency virus (HIV) in South Africa

BACKGROUND

Literature suggests that there is a correlation between video otoscopy and standard tympanometry findings. However, there is limited evidence on whether these two measures are comparable in the identification of middle ear pathologies in adults living with human immunodeficiency virus (HIV). Objective: This study aimed to determine the correlation between video otoscopy and standard tympanometry with 226 Hz probe tone in the identification of middle ear pathologies in adults living with HIV in Limpopo, South Africa. Method: A prospective, non-experimental, comparative design was employed on HIV-positive adults aged 18 years and older. All participants underwent basic audiological assessment including case history interviews, video otoscopy, tympanometry with a 226 Hz probe tone and pure tone audiometry. Two ear, nose and throat (ENT) specialists independently analysed video otoscopic images and provided their reports to the researcher, and these were compared to the tympanometry results. The IBM SPSS v.24 was used for data analysis, including the use of Cohen's kappa to determine the agreement between the two procedures. Pearson's correlation coefficient was used to determine the strength of the correlation between tympanometry and video otoscopy. Results: A total of 87 adults (N = 161 ears) took part in the study. Middle ear pathology was observed in 8% (n = 13) of the sample when tympanometry was used, and this increased to 10.6% (n = 17) when video otoscopy was utilised. Kappa statistics found a good agreement (k = 0.7) between the diagnoses made by two ENTs. However, there was poor agreement (k = 0.2) between the diagnoses by video otoscopy and tympanometry. Pearson's correlation coefficient indicated weak correlation between video otoscopy and tympanometry (r = 0.195). Conclusion: Findings from this study suggest that video otoscopy may be more accurate in the identification of middle ear pathologies in adults living with HIV when compared to tympanometry. These findings have training implications in the use of video otoscopy to ensure accuracy and reliability. Clinical implications of current findings include the use of both video otoscopy and tympanometry in a complementary manner for more sensitive identification of middle ear pathologies in this population. Lastly, tele-audiologic implications of the use of video otoscopy to increase access in resource-constrained contexts are raised.

Tympanometric evaluation of Eustachian tube function in Polish scuba divers

BACKGROUND

Scuba divers are subjected to relatively high ambient pressures while descending. Equalizing maneuvers (e.g., Valsalva) are necessary to open the Eustachian tube (ET) and allow air into the middle ear (ME) cavity. Insufficient opening of the ET leads to ME barotrauma, which is the most common injury related to scuba diving. The study aims were to assess the incidence of ME barotrauma and to compare tympanometric parameters and stapedial reflexes in scuba divers and non-diving individuals.

MATERIAL AND METHODS:

60 scuba divers participated in the study; control consisted of 90 non-diving volunteers without a history of otolaryngologic problems. All participants were examined with the use of otoscopy and tympanometry with evaluation of ipsilateral stapedial reflexes. The group studied was surveyed regarding occurrence of ME barotrauma and diving competence.

RESULTS

51.7% of the divers experienced ME barotrauma, the most common symptoms being earache and hearing loss. Comparison of the group studied and control revealed significantly lower ME pressure and compliance in scuba divers. In scuba divers with ME barotrauma, longer time from injury correlates directly with greater ME pressure and compliance, indicating tissue recovery. At 4,000Hz 100dB percentage of present stapedial reflexes among scuba divers was significantly lower than in controls; moreover, a greater number of dives correlated inversely with percentage of present stapedial reflexes at 4000Hz 100dB. The reduced thresholds at high intensities suggest a negative effect of scuba diving on hearing.

CONCLUSIONS

ME pressure and compliance, however still within the norm, are significantly lower in scuba divers than in non-diving healthy volunteers. This may be attributed to a subclinical form of barotrauma.

Relapse of B-cell acute lymphoblastic leukaemia presenting as right aural polyp with facial and mandibular nerves palsy

A patient presenting with an ear polyp is a common finding in otorhinolaryngology practice. The common causes include chronic otitis media and cholesteatoma. We report an adult female patient with a history of acute leukaemia presenting with chronic otitis media symptoms and right ear polyp. She was subsequently diagnosed as relapse of B-cell acute lymphoblastic leukaemia based on histopathological examination. The presentation may be similar to an inflammatory pathology of the middle ear, making it misleading.

Eustachian tube dysfunction leading to middle-ear pathology in patients on chronic mechanical ventilation

OBJECTIVE

This study aimed to investigate the prevalence of and risk factors for Eustachian tube dysfunction leading to middle-ear pathology in patients on chronic mechanical ventilation via tracheostomy tube.

METHODS

A total of 40 patients on chronic ventilation were included in a prospective cohort study. Middle-ear status was determined by tympanometry. Tympanograms were categorised as types A, B or C; types B and C were defined as middle-ear pathology.

RESULTS

In all, 57 ears of 40 patients were examined. Disease was found in at least 1 ear in 26 out of 40 patients. Middle-ear pathology was found in 25 out of 34 patients who were tube fed (via nasogastric tube or percutaneous endoscopic gastrostomy) vs 1 patient out of the 6 fed orally (p = 0.014), and in 23 out of 31 with conscious or cognitive impairment vs 3 out of 9 cognitively intact patients (p = 0.044).

CONCLUSION

Middle-ear pathology is common in patients on chronic mechanical ventilation via tracheostomy tube. The highest prevalence was in those with impaired consciousness or cognition, and oral feeding appeared protective.

Wideband acoustic immittance for assessing middle ear functioning for preterm neonates in the neonatal intensive care unit

BACKGROUND

The primary aim of newborn hearing screening is to detect permanent hearing loss. Because otoacoustic emissions (OAEs) and automated auditory brainstem response (AABR) are sensitive to hearing loss, they are often used as screening tools. On the other hand, false-positive results are most often because of transient outer- and middle ear conditions. Wideband acoustic immittance (WAI), which includes physical measures known as reflectance and absorbance, has shown potential for accurate assessment of middle ear function in young infants.

OBJECTIVE

The main objective of this study was to determine the feasibility of WAI as a diagnostic tool for assessing middle ear functioning in preterm neonates in the neonatal intensive care unit (NICU) designed for premature and ill neonates. A further objective was to indicate the difference between the reflectance values of tones and click stimuli.

METHOD

Fifty-six at-risk neonates (30 male and 26 female), with a mean age at testing of 35.6 weeks (range: 32-37 weeks) and a standard deviation of 1.6 from three private hospitals, who passed both the distortion product otoacoustic emission (DPOAE) and AABR tests, were evaluated prior to discharge from the NICU. Neonates who presented with abnormal DPOAE and AABR results were excluded from the study. WAI was measured by using chirp and tone stimuli. In addition to reflectance, the reflectance area index (RAI) values were calculated.

RESULTS

Both tone and chirp stimuli indicated high-power reflectance values below a frequency of 1.5 kHz. Median reflectance reached a minimum of 0.67 at 1 kHz - 2 kHz but increased to 0.7 below 1 kHz and 0.72 above 2 kHz for the tone stimuli. For chirp stimuli, the median reflectance reached a minimum of 0.51 at 1 kHz - 2 kHz but increased to 0.68 below 1 kHz and decreased to 0.5 above 2 kHz. A comparison between the present study and previous studies on WAI indicated a substantial variability across all frequency ranges.

CONCLUSION

These WAI measurements conducted on at-risk preterm NICU neonates (mean age at testing: 35.6 weeks, range: 32-37 weeks) identified WAI patterns not previously reported in the literature. High reflective values were obtained across all frequency ranges. The age of the neonates when tested might have influenced the results. The neonates included in the present study were very young preterm neonates compared to the ages of neonates in previous studies. WAI measured in at-risk preterm neonates in the NICU was variable with environmental and internal noise influences. Transient conditions affecting the sound-conduction pathway might have influenced the results. Additional research is required to investigate WAI testing in ears with and without middle ear dysfunction. The findings of the current study imply that in preterm neonates it was not possible to determine the feasibility of WAI as a diagnostic tool to differentiate between ears with and without middle ear pathology.

Non-invasive optical assessment of viscosity of middle ear effusions in otitis media

Eustachian tube dysfunction can cause fluid to collect within the middle ear cavity and form a middle ear effusion (MEE). MEEs can persist for weeks or months and cause hearing loss as well as speech and learning delays in young children. The ability of a physician to accurately identify and characterize the middle ear for signs of fluid and/or infection is crucial to provide the most appropriate treatment for the patient. Currently, middle ear infections are assessed with otoscopy, which provides limited and only qualitative diagnostic information. In this study, we propose a method utilizing cross-sectional depth-resolved optical coherence tomography to noninvasively measure the diffusion coefficient and viscosity of colloid suspensions, such as a MEE. Experimental validation of the proposed technique on simulated MEE phantoms with varying viscosity and particulate characteristics is presented, along with some preliminary results from in vivo and ex vivo samples of human MEEs. In vivo Optical Coherence Tomography (OCT) image of a human tympanic membrane and Middle Ear Effusion (MEE) (top), with a CCD image of the tympanic membrane surface (inset). Below is the corresponding time-lapse M-mode OCT data acquired along the white dotted line over time, which can be analyzed to determine the Stokes-Einstein diffusion coefficient of the effusion.

Middle Ear Resonance Frequency in Pilots and Pilot Candidates

BACKGROUND

Barotrauma is a frequent problem in aviation medicine. Eustachian tube dysfunction plays a critical role in the pathogenesis of barotrauma. Function of the Eustachian tube can be indirectly assessed by multifrequency tympanometry, which provides valuable information about the resistance and permeability of the middle ear in a wide frequency range. The aim of this study was to research whether multifrequency tympanometry could be used for assessing middle ear impairments in pilots.

METHODS

There were 140 pilots and pilot candidates between the ages of 20-55 with normal otoscopic examination who were evaluated by audiological test batteries. Body mass index values, flight hours, audiometric pure tone thresholds, tympanometry and multifrequency tympanometry test results were noted.

RESULTS

There was statistically significant decrease in the multifrequency tympanometry measurements of the left and right ears of the pilots with 200-3000 flight hours compared to pilot candidates, and similarly, the pilots with 3000-10,000 flight hours compared to pilot candidates.

DISCUSSION

Multifrequency tympanometry values changed between pilot candidates and pilots. However, the values of multifrequency tympanometry did not change due to flight hours. This test battery should not be used for follow up of pilots in the clinic. Tuncer MM, Babakurban ST, Aydin E. Middle ear resonance frequency in pilots and pilot candidates. Aerosp Med Hum Perform. 2016; 87(10):876-881.

Acoustic effects of the reconstructed lateral epitympanic wall in a temporal bone and clinical study

OBJECTIVE

Acoustic evaluation of reconstruction of the lateral epitympanic wall with bone or cartilage in a temporal bone study, and evaluation of audiometric data of patients who underwent cholesteatoma surgery with reconstruction of the lateral epitympanic wall with horseshoe-shaped cartilage.

STUDY DESIGN

Temporal bone study and retrospective chart review.

METHODS

Preparation of temporal bones included reconstruction of the epitympanic wall with fixated and loose cartilage and bone. The volume velocities of the stapes footplate were measured from the inner-ear side of the footplate by laser scanning doppler vibrometry following sound stimulation in the outer ear canal. Additionally, the audiometric data of 13 consecutive patients who underwent epitympanic cholesteatoma surgery, with an intact ossicular chain and reconstruction of the scutum with a horseshoe-shaped cartilage in contact with the malleus' neck, were evaluated retrospectively.

RESULTS

The experimental results showed similar volume velocities at the stapes footplate for the fixated and unfixated cartilage as well as for the unfixated bone. However, the fixated bone yielded significantly reduced volume velocities. Clinical data confirmed that the cartilaginous horseshoe- technique allowed for a stable reconstruction of the scutum with satisfying audiometric outcome.

CONCLUSION

In case of cholesteatoma surgery and the need for the reconstruction of the scutum, no adverse effects on hearing outcome are to be expected by using the malleus' neck as an anchoring point for cartilaginous scutum reconstruction.

LEVEL OF EVIDENCE

NA. Laryngoscope, 127:1427-1434, 2017.

Audiologic changes after pinna augmentation

No studies to date have objectively assessed whether pinna morphology affects sound intensity detected within the external auditory canal (EAC). Commonly performed procedures on the EAC are carried out for acquired and congenital pathology, together with correction of ear deformities. Our aim was to use an experimental model to identify whether a relationship exists between pinna shape and its subsequent effect on the hearing subject. An anatomically accurate and life-size model made of rubber composite was used for this study. Serial sections (small wedge, defect open; small wedge, defect closed; large wedge, defect open; large wedge, defect closed [equivalent to a protruding ear]; and pinnectomy) were undertaken, and the sound intensity changes assessed at the junction between the EAC and middle ear (tympanic membrane position) using an AURICAL Plus (Otometrics; Taastrup, Denmark) sound processor. A statistically significant loss was demonstrated for wedge-excised models, which was greatest at 180° azimuth. This loss was significantly reduced when the wedge defects were closed. A statistically significant improvement was demonstrated in the protruding ("bat") ear model compared with the normal ear at 0° azimuth. In this model, gain in sound intensity is adversely affected by pinna wedge resection. Because this change may be increased in those with protruding ears, this factor is important to consider for all cosmetic and noncosmetic operations to the pinna, and it supports the notion that the pinna is not a simple funnel.

Wideband reflectance in Down syndrome

OBJECTIVE

Children with Down syndrome (DS) have a high incidence of middle ear disorders and congenital abnormalities of the external, middle and inner ear. Energy reflectance (ER), a wideband acoustic immittance (WAI) measurement parameter, can measure the sound energy reflected or absorbed in the ear canal over a wider range of frequencies more efficiently and faster than conventional single-tone 226 Hz tympanometry. The aim of the present study was to compare the WAI measurements of children with DS with those of typically developing, normal-hearing children according to their tympanometric findings.

METHODS

Four groups of children with Down syndrome (age range: 2 years and 4 months to 16 years and 3 months; mean age: 8.5 yr) with normal tympanograms (19 ears), flat tympanograms (13 ears), mild negative pressure tympanograms (6 ears between -100 and -199 daPa at the admittance peak) and severe negative pressure tympanograms (4 ears at -200 daPa or lower at the admittance peak) were assessed. All findings were compared with data obtained from 21 ears of a healthy control group (age range: 3 years and 1 month to 13 years and 11 months; mean age: 7.9 yr). The subjects underwent tympanometry with a 226-Hz probe tone frequency and ER measurements along the 200-6,000 Hz range with a chirp stimulus using the Middle-Ear Power Analyzer (MEPA3 - HearID) by Mimosa Acoustics (Champaign, IL), software, version 3.3 [38].

RESULTS

Statistically significant differences were observed in the ER curves for some comparisons between the studied groups. There was also a negative correlation between the static acoustic admittance at the tympanic membrane level and ER measured with a chirp stimulus at 500 and 1,000 Hz. The discriminant analysis technique, which used a chirp stimulus at 1,000 and 1,600 Hz to classify the participants' data based on ER values, achieved a correct classification rate of 59.52% for participants with DS.

CONCLUSION

While groups with abnormal middle ear status, as indicated by tympanometry, showed higher ER values compared to the DS tymp A group and the control group, similar reflectance curves were observed between control group and the DS tymp A group. WAI shows promise as a clinical diagnostic tool in investigating the impact of middle ear disorders in DS group. However, further research is required to investigate this issue in narrower age range group and a larger sample size.

Middle Ear Extramedullary Hematopoiesis: A Case Report

BACKGROUND

Extramedullary hematopoiesis (EMH) in the middle ear is exceedingly rare, with fewer than five cases reported. The authors report the first Thai case of middle ear EMH

CASE REPORT

A 32-year-old Thai thalassemic man presented with complaint of right-sided hearing loss from a middle ear mass. The CT/MRI was done and the diagnosis of EMH was confirmed by a pathological examination after a surgical removal.

CONCLUSION

A differential diagnosis of EMH should also be done in thalassemic patients presented with a middle ear mass.

Local Anesthesia for Middle Ear Surgery

The adequacy of anesthesia and comfort during surgery was assessed for 100 consecutive patients undergoing middle ear surgery using local anesthesia, both by the patients themselves and by the surgeon. The possibility of inducing an iatrogenic facial weakness was also evaluated. Both the surgeon and the majority of patients were pleased with the quality of anesthesia and little adverse effects occured as a consequence of local anesthesia itself.

Standard Anesthetic Technique for Middle Ear Surgical Procedures: A Comparison of Desflurane and Sevoflurane

Objective:

This study was designed to compare desflurane and sevoflurane anesthesia for middle ear microsurgery.

Study Design:

One hundred healthy adults undergoing middle ear surgery were assigned to receive either desflurane or sevoflurane as their anesthetic. Intraoperative hemodynamics and BIS numbers were recorded. Hemodynamics, pain, nausea/vomiting, discharge readiness, and other parameters were compared postoperatively and 24 hours later.

Results:

No intraoperative differences were noted except in BIS scores which trended lower with desflurane. PACU blood pressures were higher after desflurane but pain scores, nausea/vomiting, rescue anti-emetics, recovery scores, and discharge times were similar. A significant difference was noted in anesthetic costs (desflurane > sevoflurane), and in patients with the lowest BIS scores associated with more nausea/vomiting.

Conclusions:

Both anesthetics may be used for ototic surgery but propofol anesthesia should still be considered in patients with a history of emetic sequelae.

Significance:

Short-acting inhalational anesthetics produce excellent operating conditions and reduce costs for otologic surgery.

[Complications Resulting from Taking Ear Impressions]

In 2012, we carried out a study in a large sample to understand the secondary injuries caused during the taking ear impressions for hearing aids. This study is a follow-up of previous research conducted in 1986 (285 medical institutions) and 1999 (98 medical institutions). We posted a questionnaire survey to the otolaryngology departments of 3,257 medical institutions. The response rate to the questionnaire was 62.9% (2,050 of the 3,257 institutions), and the results indicated that 301 of the 2050 institutions (14.7%) had experience with secondary injuries, with a total of 460 cases reported. In 342 of the 460 cases (74.3%), the secondary injuries occurred at hearing-aid dealerships, followed by 67 cases (14.6%) at affiliated medical institutions, and 51 cases (11.1%) in other locations, including other medical institutions, rehabilitation counseling centers, and educational institutions. The most common type of secondary injury (298 cases, 64.8%) was caused by the presence of foreign bodies in the ear, which in turn was a result of complications occurring during the removal of residual ear impression material. Of these 298 cases, 32 required excision of the foreign bodies and surgical intervention under general anesthesia. The remaining 10 cases exhibited isolated tympanic membrane perforation without foreign body-related complications. Furthermore, 146 cases (31.7%) developed bleeding and otitis externa following removal of the ear impression, and there were reports of cases with bleeding that required long-term outpatient care and treatment. Therefore, since retention of a foreign body in the ear and tympanic membrane perforation can occur even in patients without a history of surgery or prior otologic history, adjustment of hearing aids requires prior otorhinolaryngological examination. Furthermore, because of the risk of secondary injury when taking ear impressions, this procedure must be performed with caution under the guidance of an otolaryngologist.

[The eosinophilic otitis media's research progress]

The eosinophilic otitis media(EOM) is an intractable disease characterized by the presence of a highly viscous yellow effusion with extensive accumulation of eosinophils in the middle ear; granulation tissue can been discovered in the middle ear cavity; most of patients have association with bronchial asthma; resist to conventional treatment for otitis media; EOM patients show gradual deterioration of hearing and sometimes become deaf suddenly; effective treatment involves use of topical and oral steroids. This article summarizes the progress of the EOM's diagnosis and treatment.

Middle ear pressure during sleep and the effects of continuous positive airway pressure

PURPOSE

Prior studies evaluating Eustachian tube physiology, baseline middle ear pressure (MEP), and the effects of continuous positive airway pressure (CPAP) have been performed on awake patients. No study to date has specifically investigated MEP during sleep despite the fact that the average individual spends a third of their lifetime sleeping. The primary objectives of the current study are to quantify normal physiologic MEP during sleep and to evaluate the effects of escalating CPAP levels.

MATERIALS AND METHODS

Prospective observational study at a tertiary academic referral center evaluating serial tympanometry on sleeping adult patients during polysomnography. MEP was recorded awake, at 1-hour intervals during diagnostic polysomnography, and at all CPAP levels during titration. Changes in MEP with duration of sleep and escalating CPAP levels were analyzed.

RESULTS

Ten adults were included (4 females; 6 males; mean age 58years). The mean MEP while awake was 3 decapascals (daPa). The mean MEP during sleep without CPAP rose steadily from 14 daPa at 1hour to 41 daPa at 4hours (r=0.52; p<0.001). The mean MEP during sleep at a CPAP level of 5cm of water was 54 daPa. The mean MEP rose steadily with increasing CPAP levels, and was 104 daPa at 10cm of water, (r=0.82; p<0.001). The mean MEP during sleep without CPAP was 26 daPa, which was significantly lower than the mean MEP during sleep with CPAP between 5-10cm H2O (p<0.01).

CONCLUSIONS

MEP naturally increases with duration of sleep. CPAP therapy causes a supraphysiologic elevation in MEP that rises with increasing pressure levels. These findings may help guide future studies examining the safety of CPAP following otologic surgery and the potential therapeutic benefit in patients with chronic middle ear disease.

[The application of ultrasound for diagnostics of middle ear pathologies]

The objective of the present work was to summarize the results of the application of ultrasound tests for differential diagnostics of various diseases and lesions affecting the middle ear. Almost 7.000 threshold and suprathreshold studies were carried out in the patients presenting with various forms of sensorineural impairment of hearing. The ultrasound investigations were conducted with the use of the EKHOTEST-02 apparatus (Giperion, Moscow). The results of determination of threshold hearing sensitivity to ultrasound and lateralization of its threshold and suprathreshold values suggest their significance for the detection of even such a minimal disturbance in the cochlear function as the phenomenon of accelerated increase in loudness and the associated enhancement of the severity of the damage to the peripheral sensory system.

Middle ear pressure changes with sevoflurane and propofol-remifentanil

The present study aimed to compare the effects of sevoflurane (a commonly used inhalation anesthetic) and intravenous propofol on middle ear pressure (MEP) and determine the more appropriate option for middle ear operations. Fifty-seven American Society of Anesthesiologists risk class I-II patients aged 18-65 years who were not scheduled for ear or tympanic membrane operations were included in the study. The patients were randomly divided into two groups using the sealed envelope method. Propofol (0.2-0.5 mg/kg; Group P) and sevoflurane (1-2%; Group S) were used to maintain anesthesia. Baseline tympanometry was conducted on both ears and recorded before anesthesia was induced. Four additional measurements were performed and recorded at 5, 10, 15, and 30 minutes after induction. All post-induction MEP values were significantly higher than baseline measurements in Group S (P < 0.05 for all); there were no differences between post-induction and baseline measurements in Group P. At 10, 15, and 30 min post-induction, MEP values were significantly higher in Group S than in Group P (P < 0.05). Sevoflurane increased MEP values significantly compared with propofol anesthesia. We conclude that propofol can be used more reliably than sevoflurane in middle ear operations.

[Acoustic impedanceometry: the evolution of diagnostic possibilities]

The present review of the literature reports the materials concerning the application of the acoustic impedance measurements of normal ears and pathologically charged organs of hearing that are important for the differential diagnostics and monitoring of the hearing system condition during the conservative and surgical treatment.

Sevoflurane vs. TIVA in terms of middle ear pressure during laparoscopic surgery

OBJECTIVES

The aim of this study was to investigate the effects of CO2 insufflation on the pressure of the middle ear cavity (PMEC) during laparoscopic surgery under total intravenous anesthesia (TIVA) with propofol or sevoflurane as an inhalational anesthetic maintenance.

MATERIAL AND METHODS

Sixty patients who underwent laparoscopic/or non-laparoscopic surgery under general anesthesia were included in the study. For anesthetic maintenance with inhalation agents, 20 non-laparoscopic surgery patients in Group 1 were applied sevoflurane (2-2.5%). Forty patients who underwent laparoscopic surgery were randomized into two groups. Anesthesia was maintained with sevoflurane (2-2.5%) in twenty patients in Group 2 and the TIVA technique in 20 patients in Group 3. In Group 1, PMEC was measured before anesthesia, 10 and 30 min after endotracheal intubation, 10 min before extubation, and 15, 30, 60 min and 6 hours in the postoperative period. In Group 2 and 3, PMEC was measured before the anesthesia, 10 min after intubation, 10 and 30 min after CO2 insufflation, just before the CO2 elimination, 10 min before the extubation, and 15, 30, 60 min and 6 hours after extubation in the postoperative period.

RESULTS

PMEC was significantly increased in Group 1 at 10 min after intubation, at 30 min of the operation, before extubation, and at postoperative 15 and 30 min (p < 0.05). In Group 3, differences between PMECs were detected at the 30th min of insufflation (p = 0.005), and during elimination (p = 0.035) compared to the initial measurement. Generally, the values remained positive in Group 1 and negative in Group 3. There was a significant difference between Group 1 and Group 3 at 10 min after the induction (p = 0.001). There was no statistically significant difference in PMECs between Group 2 and 3 patients undergoing laparoscopic surgery.

CONCLUSIONS

Our results indicate that, in laparoscopic surgery, TIVA used for the maintenance of anesthesia did not increase the PMEC and the changes caused by sevoflurane were also in the normal range of middle ear pressures. In patients with previous ear surgery, if there is a need of classical surgical procedures in the future, sevoflurane anesthesia should not be the first choice due to its effects on PMEC, which cause it to be increased over 50 daPa, especially at 30 min after intubation. Patient characteristics including previous ear surgery should be considered in selecting the optimum anesthetic agents and technique.

[Multiple factors quantitative analysis on middle ear function in primarily diagnosed patients with nasopharyngeal carcinoma]

OBJECTIVE

To explore the ways of quantitative and objective evaluation for analyzing the multiple influence factors on middle ear function in the patients with primarily diagnosed NPC, and to analyze the influence factors of middle ear function in the patients with primarily diagnosed nasopharyngeal carcinoma (NPC).

METHOD

Three hundred and twenty cases (320 ears) of primarily diagnosed NPC patients were examinated with electric otoscope, acoustic immittance measurement, pure tone audiometry, nasopharynx and middle ear CT or MRI scanning, eustachian tube function examination, and electronic nasopharyngoscope. A series of quantitative methods, as the influence factors including T stage, clinical stage, location, diffusion type and form of tumor, eustachian tube function, pharynx mouth shape, imaging extension (nasal, skull base, pharyngeal recess, parapharyngeal space, tensor veli palatini muscle, levator veli palatini and so on), were used to evaluate the middle ear function. SPSS 13.0 was used to anlyze the single and multiple factors in statistics.

RESULT

T stage, clinical stage, location, diffusion type, and form of tumor, pharynx mouth shape, imaging extension (nasal, skull base, pharyngeal recess, parapharyngeal space, tensor veli palatini muscle, levator veli palatini) were the single influence factors on the function of middle ear in primarily diagnosed NPC patients. The gender, age, pathological types, N staging and M staging of NPC patients primarily diagnosed had no effect on middle ear function. The multple factors analysis showed that T stage, tumor location, the function of eustachian tube, tensor veli palatini muscle invasion, and skull base invasion were independent factor of affecting the middle ear function on primarily diagnosed NPC patients.

CONCLUSION

In this study, the influence factors of middle ear function with primarily diagnosed NPC were related to T stage, location of tumor, the function of eustachian tube, tensor veli palatini muscle invasion, skull base invasion, otitis media and quantitative criteria. The way of quantitative analysis could be used to evaluate objectively the middle ear function in patients with primarily diagnosed NPC.

[Clinical analysis of ten cases of congenital middle ear cholesteatoma]

OBJECTIVE

To investigate the clinical features and operation treatment of the congenital middle ear cholesteatoma.

METHOD

A retrospective review of clinical and surgical records of 10 patients with congenital middle ear cholesteatoma were performed. All patients were treated by surgeries,5 of 10 cases deal with one-stage tympanoplasty after drum exploration by external auditory meatus, 3 cases dealed with closed mastoidotympanectomy and tympanomastoidectomy, 2 cases dealed with open mastoidotympanectomy and tympanomastoidectomy.

RESULT

The cholesteatomas were located at or around the posterior tympanum or mesotympanum in 5 patients, confined to the tympanic cavity and attic in 3 patients, advanced cholesteatoma that extended from the tympanic cavity into the mastoid antrum was seen in 2 patients. The mean postoperative PTA was 30 dB HL, the mean ABG was within 20 dB, after six months. No residual or recurrence of cholesteatoma was found.

CONCLUSION

The congenital cholesteatoma often originates from the posterior or anterior of the middle ear, with hiding lesion, thus result in severe conductive hearing loss. Imaging examination plays an important role in diagnosing and treating of congenital cholesteatoma. Early stage surgical treatment can obtain a good hearing reconstruction effect.

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.

Hearing loss in a mouse model of 22q11.2 Deletion Syndrome

22q11.2 Deletion Syndrome (22q11DS) arises from an interstitial chromosomal microdeletion encompassing at least 30 genes. This disorder is one of the most significant known cytogenetic risk factors for schizophrenia, and can also cause heart abnormalities, cognitive deficits, hearing difficulties, and a variety of other medical problems. The Df1/+ hemizygous knockout mouse, a model for human 22q11DS, recapitulates many of the deficits observed in the human syndrome including heart defects, impaired memory, and abnormal auditory sensorimotor gating. Here we show that Df1/+ mice, like human 22q11DS patients, have substantial rates of hearing loss arising from chronic middle ear infection. Auditory brainstem response (ABR) measurements revealed significant elevation of click-response thresholds in 48% of Df1/+ mice, often in only one ear. Anatomical and histological analysis of the middle ear demonstrated no gross structural abnormalities, but frequent signs of otitis media (OM, chronic inflammation of the middle ear), including excessive effusion and thickened mucosa. In mice for which both in vivo ABR thresholds and post mortem middle-ear histology were obtained, the severity of signs of OM correlated directly with the level of hearing impairment. These results suggest that abnormal auditory sensorimotor gating previously reported in mouse models of 22q11DS could arise from abnormalities in auditory processing. Furthermore, the findings indicate that Df1/+ mice are an excellent model for increased risk of OM in human 22q11DS patients. Given the frequently monaural nature of OM in Df1/+ mice, these animals could also be a powerful tool for investigating the interplay between genetic and environmental causes of OM.

Wideband energy reflectance measurements: effects of negative middle ear pressure and application of a pressure compensation procedure

The wideband energy reflectance (ER) technique has become popular as a tool for evaluating middle ear function. Negative middle ear pressure (MEP) is a prevalent form of middle ear dysfunction, which may impact application of ER measurements in differential diagnosis. A negative MEP may be countervailed by application of an equivalent negative ear canal pressure. The present study examined ER in the same ears under normal and experimentally induced negative MEP conditions. Thirty-five subjects produced at least one negative MEP each (-40 to -225 daPa). Negative MEP significantly altered ER in a frequency-specific manner that varied with MEP magnitude. ER increased for low- to mid-frequencies with the largest change (~0.20 to 0.40) occurring between 1 and 1.5 kHz. ER decreased for frequencies above 3 kHz with the largest change (~-0.10 to -0.25) observed between 4.5 and 5.5 kHz. Magnitude of changes increased as MEP became more negative, as did the frequencies at which maximum changes occurred, and the frequency at which enhancement transitioned to reduction. Ear canal pressure compensation restored ER to near baseline values. This suggests that the compensation procedure adequately mitigates the effects of negative MEP on ER. Theoretical issues and clinical implications are discussed.

Dynamic characteristics of the middle ear in neonates

OBJECTIVE

Early diagnosis and treatment of hearing disorders in neonates is highly effective for realization of linguistic competence and intellectual development. To objectively and quickly evaluate the dynamic characteristics of the middle ear, a sweep frequency impedance (SFI) meter was developed, which allowed the diagnosis of middle-ear dysfunctions in adults and children. However, this SFI meter was not applicable to neonates since the size of the measurement probe was too large. In the present study, therefore, the SFI meter was improved, i.e., the diameter of the probe was reduced to that of the neonatal external ear canal. By using this newly designed SFI meter, SFI tests were performed in healthy neonates.

METHODS

A sound of the sweeping sinusoidal frequency between 0.1 kHz and 2.0 kHz in 0.02-kHz step intervals is presented to the ear canal by an SFI probe while the static pressure of the ear canal is kept constant. During this procedure, the sound pressure level (SPL) is measured. The measurements are performed at 50-daPa intervals of static pressure from 200 daPa to -200 daPa.

RESULTS

Measurements were conducted in 10 ears of 9 neonates. The SPL showed two variations at 0.26 ± 0.03 kHz and 1.13 ± 0.12 kHz. Since the SPL is known to show a variation at frequencies from 1.0 kHz to 1.6 kHz due to the resonance of the middle ear in adults and children with normal hearing, the second variation is probably related to such resonance in neonates. The measurement of gel models, which mimics the neonatal external ear canal, showed a variation in SPL at around 0.5 kHz. This implies that the source of the first variation may possibly be related to the resonance of the external ear canal wall.

CONCLUSIONS

SFI tests revealed that there were two variations in the SPL curve in neonates, one at 0.26 ± 0.03 kHz and the other at 1.13 ± 0.12 kHz, the former and the latter being possibly related to the resonance of the external ear canal wall and that of the middle ear, respectively. This result suggests that the dynamic characteristics of the middle ear in neonates are different from those in adults.

Absent stapedial reflex: otosclerosis or middle ear tumor?

We present an unusual case in which a patient diagnosed as having otosclerosis on the basis of clinical and audiologic findings actually had a middle ear facial nerve schwannoma. To the best of our knowledge, this is the first reported case in English literature in which a facial nerve schwannoma presented with conductive deafness of gradual onset and absent stapedial reflex with a normally functioning facial nerve. We also include a review of the literature.

Time-dependent middle ear pressure changes under general anaesthesia in children: N2O-O2 mixture versus air-oxygen mixture

OBJECTIVES

The aim of this study was to investigate the effects of N2O-O2 mixture (Inspired O2 30%) on middle ear pressure (MEP) in children compared with the effects of an air-oxygen mixture (Inspired O2 50%).

METHOD

The study included thirty child patients who underwent general anaesthesia for different reasons, with the exception of ENT problems and ear interventions. They were randomly divided into two groups. Group 1 (15 children: 10 male and 5 female) received a N2O-O2 mixture (Inspired O2 30%); and group 2 (15 children: 10 male and 5 female) were given an air-oxygen mixture (Inspired O2 50%). MEP was measured using a portable impedance analyser before the operation (PreO),10 minutes after intubation (10AEn), 30 minutes after intubation (30AEn), 10 minutes before extubation (10BEx), 15 minutes after the operation (PO15), 30 minutes after the operation (PO30), 1 hour after the operation (PO1h) and 6 hours after the operation (PO6h).

RESULTS

The pressure and compliance values were the same in groups 1 and 2. The pressure-time graphs for the two groups were different: in Group 2, MEP rose quickly at 10AEn and positive pressure values were seen in the middle ear. MEP then fell rapidly until the end of the surgery and lower and negative pressures (Mean -50 daPa) were observed at PO6h. In Group 1, MEP was elevated at 10AEn and positive pressure was found (but not as high as in Group 2). MEP then fell more slowly. In other words, positive pressure in the middle ear persisted longer and the middle ear was subjected to positive pressure and nitrogen over a longer period. Separate analyses were made in Groups 1 and 2 of pressure differences and of compliance values at eight measurement points using the Friedman test. Differences in pressure values were found to be statistically significant in both Group 1 (p = 0.000) and Group 2 (p = 0.000). In Group 1, all the 10AEn and 30AEn values were significantly higher than the PreO, PO30, PO1h and PO6h values. The 10BEx value was significantly higher than the PreO and PO1h values. The PO15 value was significantly higher than the PreO value. In Group 2, the PO6h value was significantly lower than the 10BEx, 10AEn and 30AEn values. The PO1h value was significantly lower than the 30AEn values. The MEP values increased in Group 1 in younger and taller children and in children receiving anaesthesia for shorter periods. MEP values increased in Group 2 in younger and taller children, and in heavier children. MEP values fell with the length of anaesthesia.

CONCLUSION

In brief anaesthesia, nitrogen was not removed from the middle ear quickly in Group 1: middle ear pressure values were higher. The nitrous oxide remained in the middle ear longer and so the possibility of ear toxicity may increase. In Group 2, 50% O2 was rapidly absorbed and removed from the middle ear and so middle ear pressure was not as high. It may be concluded that air-oxygen mixture (Inspired O2 50%) anaesthesia should be recommended as being more reliable in tympanoplasties and other middle ear interventions than a N2O-O2 mixture (Inspired O2 30%).

Introducing endoscopic ear surgery into practice

The otolaryngologist will find in this article a direct and frank discussion and useful advice for how to get started performing solely endoscopic ear surgery for abnormalities of the middle ear. The author provides discussion and photos based on his experience with this procedure. Presented herein are selection of the endoscope, how to approach the first fully endoscopic procedure, patient selection, preoperative planning, setting up the operating room, pitfalls typically encountered, and how to gain skills to perform this procedure successfully.

Negative middle ear pressure and otitis media with effusion after surgery under general anesthesia

CONCLUSION

Negative middle ear pressure was observed in many patients and otitis media with effusion (OME) developed in 3.3% of ears after surgery under general anesthesia. Gas dynamics in the middle ear cavity induced by nitrous oxide inhalation anesthesia and transient blockage of the eustachian tube induced by surgery are considered to be involved in development of OME after surgery under general anesthesia.

OBJECTIVES

The goal of this prospective study was to investigate middle ear pressure and the prevalence of middle ear effusion in patients after surgery under general anesthesia, to ascertain whether surgery under general anesthesia induces OME.

METHODS

Otoscopic inspection and tympanometry were performed before surgery (Pre), 1-2 days after surgery (Post-1), and 5-9 days after surgery (Post-2) under general anesthesia in 180 ears of 97 adult patients.

RESULTS

Effusion accumulated in the tympanum in six ears (3.3%) of five patients at Post-1. All patients were anesthetized with nitrous oxide. At Post-2, effusion disappeared in all cases. The mean middle ear pressure in all ears was -17.8 daPa at Pre and -60.6 daPa at Post-1, showing a significant reduction from Pre to Post-1 (p < 0.001). At Post-2, the pressure was -18.4 daPa, with no significant difference from that at Pre (p = 0.74).

Intraoperative CT-guided cochlear implantation in congenital ear deformity

CONCLUSIONS

Intraoperative computed tomography (iCT)-guided cochlear implantation is practical and effective for correct electrode placement in the cochlea of patients with congenital inner ear and/or complex middle ear malformation.

OBJECTIVES

The operation in patients with inner ear and/or complex middle ear malformation including abnormal facial nerve course is difficult. This study evaluated the efficacy of cochlear implantation under the guidance of iCT to insure correct electrode placement.

METHODS

This was a prospective interventional case series. Ten patients with severe to profound sensorineural hearing loss due to ear malformations were enrolled, and iCT was used to confirm the right placement of electrodes.

RESULTS

Intraoperative CT was performed three times in one patient, twice in two, and once in the others. Interruption of the surgical process for each iCT until resumption of surgery was 9.64 ± 0.63 min. iCT revealed incorrectly positioned cochlear implants in two patients, which were immediately corrected. There were no reoperations due to misplacement of electrodes. iCT helped locate the cochlea in the middle ear of one patient with an abnormal facial nerve course. The overall intervention rate based on iCT findings was 30%.

LEVEL OF EVIDENCE

level 4.

Persistent alternobaric vertigo at ground level

We recently encountered a 15-year-old female with bilateral tympanostomy tubes who manifested persistent severe vertigo, at ground level, secondary to a unilateral middle-ear pressure of +200 mm H(2)O elicited by an obstructed tympanostomy tube in the presence of chronic nasal obstruction. We believe this is a previously unreported scenario in which closed-nose swallowing insufflated air into her middle ears, resulting in sustained positive middle-ear pressure in the ear with the obstructed tube. Swallowing, when the nose is obstructed, can result in abnormal negative or positive pressures in the middle ear, which has been termed the Toynbee phenomenon. In patients who have vertigo, the possibility that nasal obstruction and the Toynbee phenomenon are involved should be considered.

Long-term middle ear pressure measurements in inner ear disorders

CONCLUSION

Repetitive portable tympanometry is a feasible method to examine long-term middle ear pressure profile. This method might be suitable for detecting patients with Meniere's disease whose middle ear pressure shows intermittently pathological values.

OBJECTIVES

Contradictory study results regarding middle ear pressure in patients with Meniere's disease might be due to solitary tympanometric measurements. Pathological pressure conditions in patients with pressure regulation disorders might be missed by a single examination. The aim of the study was to examine the pressure profile of patients with Meniere's disease by long-term measurements.

METHODS

Patients with Meniere's disease (n = 33), patients with sudden hearing loss (n = 20), and healthy subjects (n = 30) were examined. Patients carried out long-term middle ear pressure measurements with the portable tympanometer Otoflex 100. Examinations were carried out during daily activities at defined time intervals.

RESULTS

Significant negative middle ear pressure were seen in patients with Meniere's disease compared with patients with sudden hearing loss and healthy subjects (p < 0.01). Average middle ear pressure in patients with Meniere's disease was -43 daPa, in patients with sudden hearing loss it was 2 daPa, and in healthy subjects it was 4 daPa. Patients with Meniere's disease showed a large variability of pressure values ranging from strongly pathological to normal values during long-term measurements.