Control Ears Research Articles

The Diagnostic Value of Multifrequency Tympanometry in Patients with Ménière’s Disease: A Prospective Analysis

Introduction: Diagnosing Ménière’s disease (MD) by its characteristics such as episodes of vertigo, fluctuating hearing loss, and tinnitus with aural fullness remains challenging. Available tests evaluating the presence of endolymphatic hydrops (EH) are often expensive or time assuming. An in-office quick and simple non-invasive diagnostic test is multifrequency tympanometry (MFT). It can measure conductance at 2 kHz probe tones, which was demonstrated to reflect variations in cochlear pressure. Previous studies investigating MFT as a diagnostic test for MD showed conflicting outcomes possibly biased by their retrospective design. Methods: We prospectively collected MFT results (Y width) in patients with dizziness and compared MFT test results in affected (group 1) and unaffected (group 2) ears of 37 MD subjects and in control ears of 33 non-MD subjects (group 3). Results: The mean value of the Y width in affected ears was 315.6 ± 70.2 daPa compared to 292.3 ± 98.6 daPa in unaffected ears in MD subjects and 259.4. ± 60.6 daPa in the non-MD group. A positive test result (i.e., a Y width of 235 daPa or more) was found in 35 ears in the MD group, 21 times involving the affected ear and 14 times involving the unaffected ear, compared to 16 in the non-MD group. No significant differences between the three groups could be demonstrated (p > 0.05). We found a sensitivity of 58.3% and specificity of 66.3% for detecting EH in an affected ear in MD subjects. Conclusion: There is a trend towards increased conductance tympanometry in affected ears. However, we noticed a high false positive rate of MFT and do not support standardized use of MFT as an additional diagnostic tool for detecting EH in MD patients. A negative test result on the contrary is unlikely related to EH.

Radiological presence of vascular loops in the cerebellopontine angle region in patients with unilateral Ménière’s disease

ObjectiveThe relationship between vascular compression of the vestibulocochlear nerve and audio-vestibular symptoms remains controversial. We aimed to examine the radiological features of vascular loops signs in cerebellopontine angle (CPA) and internal auditory canal (IAC) in patients with unilateral Ménière’s disease (MD).MethodsOne hundred and thirty-seven patients with unilateral definite MD and 69 control subjects (138 ears) were enrolled. All subjects received magnetic resonance imaging of CPA-IAC. The configuration of vascular loops in CPA-IAC, based on the Kazawa classification system, from MD-affected, non-affected and control ears were compared. The associations between imaging findings and Ménière’s stage, electrocochleogram (EcochG) and caloric test were analyzed.Results(1) Among the MD-affected ears, 6 cases (4.4%) were classified as Kazawa type IA, 27 cases (19.7%) as IB, 60 cases (43.8%) as IIA, and 44 cases (32.1%) as IIB. No significant interaural difference in the distribution of Kazawa's types was found ({x}^{2} = 4.737, p = 0.578) in unilateral MD patients. (2) The distribution of Kazawa's types were not significantly different between the MD-affected ears and the control subjects ({x}^{2} = 2.876, p = 0.411). (3) No relationship was found between Kazawa staging of the MD-affected ear and Ménière’s stage (H = 2.679, p = 0.444), EcochG ({x}^{2} = 0.827, p = 0.867) and caloric test ({x}^{2} = 4.116, p = 0.248).ConclusionsIn patients with unilateral MD, the configuration of vascular loops in CPA-IAC region, measured by Kazawa criteria, did not correlate with the laterality, clinical stage, the results of EcochG and caloric test, suggesting that vascular loops may be natural anatomical variations for patients with MD.

Vestibulotoxicity in Patients Undergoing Cisplatin-Based Cancer Treatment: A Phase IIIB Randomized Controlled Clinical Trial

Introduction: This study aimed to evaluate the incidence of balance disorders and the efficacy of dexamethasone in protecting patients undergoing cisplatin-based cancer treatment against vestibulototoxicity. Methods: This study was a randomized controlled phase IIIB clinical trial. The subjects participating in the clinical trial were patients with a neoplastic disease whose treatment protocol included cisplatin. The average dose of cisplatin was 444.87 mg (SD 235.2 mg). Treatment consisted of intratympanically administering dexamethasone via a passive diffusion device called Microwick (8 mg/24 h dose) from the start of treatment with cisplatin to 3 weeks after the last cycle. Patients were administered the medication to one ear, and the contralateral ear was used as the control. The treated ears were randomly chosen using a computer system (randomization). Vestibular system was evaluated by video head impulse test before each cisplatin cycle. Results: Thirty-four patients were recruited over a 2-year period at a reference tertiary hospital, of whom 11 were excluded. Forty-six ears were analyzed (23 treated and 23 control ears). Vestibular analysis presented no changes in the mean increase in the vestibulo-ocular response in all patients evaluated, both in treated and control ears. Both 8.69% infection complications during treatment and 34.8% permanent perforation at 6 months were detected after device removal. Conclusion: Ototoxicity related to cisplatin-based treatment does not affect the vestibular system. Long-term high-dose intratympanic dexamethasone treatment is safe for the vestibular system.

Intratympanic Botulinum Toxin Injection as a New Therapeutic Modality for Middle Ear Myoclonic Tinnitus.

Middle ear myoclonic tinnitus (MEMT) is a disease caused by myoclonus or abnormal contractive movement of middle ear muscles (MEMs). This translational study was conducted to propose intratympanic botulinum toxin (IT-BTX) injection as a new therapeutic modality to treat MEMT. Animal experiment and nonrandomized controlled clinical trial. Laboratory and medical center of an academic tertiary medical institution. For the animal study, male Sprague-Dawley rats were divided into 4 subgroups according to the sacrificing day after IT-BTX injection. After initial hearing tests, randomly assigned experimental ears were intratympanically injected with 1 unit/100 μL of BTX-A, whereas control ears were injected with normal saline. Changes in the hearing thresholds, morphometry of the cochleae, electron microscopy study, and immunofluorescence analysis of MEMs were evaluated. For the human study, 10 intractable MEMT patients were enrolled. The hearing thresholds and the degree of tinnitus distress were observed for changes after IT-BTX injection. All patients were followed up for 3 months. As for the animal study, there were no significant changes in hearing thresholds and cochlear morphologies in all 4 subgroups of the rats. Significant MEM degenerations and immuno-detection of cleaved synaptosome-associated protein of 25 kDa (cSNAP-25) indicated the efficacy of IT-BTX. MEMT patients enrolled for the pilot clinical trial showed statistically significant improvement in tinnitus after IT-BTX injection. No major complications were noted. The new therapeutic modality of IT-BTX injection for the treatment of MEMT seems highly promising with an excellent result.

Sonoporation of the Round Window Membrane on a Sheep Model: A Safety Study.

Sonoporation using microbubble-assisted ultrasound increases the permeability of a biological barrier to therapeutic molecules. Application of this method to the round window membrane could improve the delivery of therapeutics to the inner ear. The aim of this study was to assess the safety of sonoporation of the round window membrane in a sheep model. To achieve this objective, we assessed auditory function and cochlear heating, and analysed the metabolomics profiles of perilymph collected after sonoporation, comparing them with those of the control ear in the same animal. Six normal-hearing ewes were studied, with one sonoporation ear and one control ear for each. A mastoidectomy was performed on both ears. On the sonoporation side, Vevo MicroMarker® microbubbles (MBs; VisualSonics-Fujifilm, Amsterdam, The Netherlands) at a concentration of 2 × 108 MB/mL were locally injected into the middle ear and exposed to 1.1 MHz sinusoidal ultrasonic waves at 0.3 MPa negative peak pressure with 40% duty cycle and 100 μs interpulse period for 1 min; this was repeated three times with 1 min between applications. The sonoporation protocol did not induce any hearing impairment or toxic overheating compared with the control condition. The metabolomic analysis did not reveal any significant metabolic difference between perilymph samples from the sonoporation and control ears. The results suggest that sonoporation of the round window membrane does not cause damage to the inner ear in a sheep model.

Conductive Hearing Loss Estimated From Wideband Acoustic Immittance Measurements in Ears With Otitis Media With Effusion.

Previous work has shown that wideband acoustic immittance (WAI) is sensitive to the volume of effusion present in ears with otitis media with effusion (OME). Prior work also demonstrates that the volume of the effusion appears to drive, or at least play a significant role in, how much conductive hearing loss (CHL) a child has due to a given episode of OME. Given this association, the goal of this work was to determine how well CHL could be estimated directly from WAI in ears with OME. Sixty-three ears from a previously published study on OME (ages 9 months to 11 years, 2 months) were grouped based on effusion volume (full, partial, or clear) determined during tympanostomy tube placement surgery and compared with age-matched normal control ears. Audiometric thresholds were obtained for a subset of the 34 ears distributed across the four groups. An electrical-analog model of ear-canal acoustics and middle-ear mechanics was fit to the measured WAI from individual ears. Initial estimates of CHL were derived from either (1) average absorbance or (2) the model component thought to represent damping in the ossicular chain. The analog model produced good fits for all effusion-volume groups. The two initial CHL estimates were both well correlated (87% and 81%) with the pure-tone average hearing thresholds used to define the CHL. However, in roughly a third of the ears (11/34), the estimate based on damping was too large by nearly a factor of two. This observation motivated improved CHL estimates. Our CHL estimation method can estimate behavioral audiometric thresholds (CHL) within a margin of error that is small enough to be clinically meaningful. The importance of this finding is increased by the challenges associated with behavioral audiometric testing in pediatric populations, where OME is the most common. In addition, the discovery of two clusters in the damping-related CHL estimate suggests the possible existence of two distinctly different types of ears: pressure detectors and power detectors.

Bilateral Dysfunction of Otolith Pathway in Patients With Unilateral Idiopathic BPPV Detected by ACS-VEMPs.

ObjectiveTo observe the functional status of the otolith pathway in patients with unilateral idiopathic benign paroxysmal positional vertigo (BPPV) by combining air-conducted sound elicited cervical vestibular-evoked myogenic potential (ACS-cVEMP) and ocular vestibular-evoked myogenic potential (ACS-oVEMP).MethodsOne hundred and eighty patients with BPPV were recruited for conventional cVEMP and oVEMP tests. The abnormal rates of VEMPs were compared between BPPV patients and control participants.ResultsThe abnormal rates of cVEMP and oVEMP in BPPV patients were 46.7% (84/180) and 57.2% (103/180) in affected ears, respectively, and 45.0% (81/180) and 56.7% (102/180) in unaffected ears, respectively; both were significantly higher than the abnormal rates of cVEMP and oVEMP in normal control ears. Compared with normal subjects, the cVEMP response rate was lower in affected and unaffected ears in BPPV patients. The abnormal rates of cVEMP and oVEMP were 48.1% (76/158) and 57.6% (91/158) in patients with posterior semicircular canal BPPV, and 36.4% (8/22) and 54.5% (12/22) in lateral semicircular canal BPPV. There was no significant difference in VEMP abnormalities between posterior semicircular canal BPPV and lateral semicircular canal BPPV.ConclusionThe prevalence of abnormal cVEMPs and oVEMPs in both affected and unaffected ears of patients with BPPV was significantly higher than that observed in the control group. The pathological mechanism of unilateral idiopathic BPPV may be associated with bilateral degeneration of otolith pathways.

Rescue of autosomal dominant hearing loss by in vivo delivery of mini dCas13X-derived RNA base editor

Programmable RNA editing tools enable the reversible correction of mutant transcripts, reducing the potential risk associated with permanent genetic changes associated with the use of DNA editing tools. However, the potential of these RNA tools to treat disease remains unknown. Here, we evaluated RNA correction therapy with Cas13-based RNA base editors in the myosin VI p.C442Y heterozygous mutation (Myo6C442Y/+) mouse model that recapitulated the phenotypes of human dominant-inherited deafness. We first screened several variants of Cas13-based RNA base editors and guide RNAs (gRNAs) targeting Myo6C442Y in cultured cells and found that mini dCas13X.1-based adenosine base editor (mxABE), composed of truncated Cas13X.1 and the RNA editing enzyme adenosine deaminase acting on RNA 2 deaminase domain variant (ADAR2ddE488Q), exhibited both high efficiency of A > G conversion and low frequency of off-target edits. Single adeno-associated virus (AAV)-mediated delivery of mxABE in the cochlea corrected the mutated Myo6C442Y to Myo6WT allele in homozygous Myo6C442Y/C442Y mice and resulted in increased Myo6WT allele in the injected cochlea of Myo6C442Y/+ mice. The treatment rescued auditory function, including auditory brainstem response and distortion product otoacoustic emission up to 3 months after AAV-mxABE-Myo6 injection in Myo6C442Y/+ mice. We also observed increased survival rate of hair cells and decreased degeneration of hair bundle morphology in the treated compared to untreated control ears. These findings provide a proof-of-concept study for RNA editing tools as a therapeutic treatment for various semidominant forms of hearing loss and other diseases.

Is tympanic infrared thermometry valid in non-naive tympanic membranes?

To investigate the impact of with tympanostomy tubes (TT) on infrared tympanic membrane thermometer (ITMT) results and to provide a systematic review of ITMT results in non-naïve tympanic membranes. Original prospective blinded case series and systematic literature review. A single tertiary university-affiliated medical center. ITMT measurements of patients with unilateral TT and contralateral naïve control ear were randomly conducted by a single investigator blinded to the TT side before and after cerumen was removed from the external auditory canals. A systematic literature search of "MEDLINE" via "PubMed," "Embase," and "Google Scholar" on comparable published cases was performed. The mean paired differences (95% confidence interval [CI]) between ventilated and non-ventilated ears before and after cerumen removal were 0.08 ºC/0.14 ºF (-0.04 to 0.19 ºC/-0.07º-0.34º) and 0.62 ºC/1.12 ºF (0.04-0.25 ºC/0.07-0.45 ºF), respectively (P < 0.001 and P = 0.01, respectively). These findings support the validity and accuracy of ITMT in the setting of ventilated ears.

Endophytic bacteria derived from the desert-spurge (Euphorbia antiquorum L.) suppress Fusarium verticillioides, the causative agent of maize ear and root rot

Fungal plant pathology is a huge concern to the agricultural industry across the globe. Fusarium verticillioides is recognized as the most widespread and severe pathogenic fungus associated with maize production. This study aimed to investigate the antagonistic potential of twenty-seven (27) endophytic bacteria from the Desert spurge (Euphorbia antiquorum L.) against Fusarium verticillioides causing ear and root rot in maize. The in vitro screening revealed that six (6) bacteria restricted Fusarium verticillioides mycelial growth upon direct confrontation, resulting in a 68.59% reduction and nine (9) inhibited via the production of VOMs (71.7% mycelial growth reduction). In vitro, all the tested bacteria produced several extracellular enzymes and various plant growth-promoting factors, such as indole acetic acid (IAA), ammonia, siderophores and solubilized phosphate. In the greenhouse experiment, potent endophytic bacteria significantly lowered the severity of ear and root rot disease caused by F. verticillioides in maize seedlings, with Citrobacter fruendii LPR4+ being the most effective. Moreover, the protective effect was strongly associated with PGP aptitudes, which was manifested by increases in root and shoot development by up to 79 and 28%, respectively, as well as guaiacol peroxidase and phenylalanine ammonialyase specific activities. The current data constitute the starting point toward an ecological solution to control ear and root rot disease in maize.

The relationship between dimensions of the Eustachian tube and acquired attic cholesteatoma.

This study investigated the relationship between physical dimensions of the Eustachian tube and the emergence of primary attic cholesteatoma. A total of 31 patients with unilateral attic cholesteatoma were selected for radiological comparison. Standard point measurements as well as specific measurements were performed using imaging software. The length, narrowest diameter and bony segment volume, and pharyngeal orifice diameter of both sides of the Eustachian tube (attic cholesteatoma and healthy control ears) were measured and compared. Comparison of the values did not reveal any statistically significant difference between the attic cholesteatoma ears and the healthy control ears in terms of: Eustachian tube height, narrowest diameter, bony segment volume or pharyngeal orifice diameter. No statistically significant difference was found between the cholesteatoma ears and the healthy control ears in terms of the osseous Eustachian tube size. The findings indicate that the Eustachian tube bony segment dimensions and pharyngeal orifice diameter are not factors in attic cholesteatoma development.

Minimally invasive trans-tympanic eustachian tube occlusion animal model

ObjectiveEustachian tube dysfunction is believed to be involved in the pathogenesis of many middle ear diseases including chronic suppurative otitis media. We aimed to describe a simple and reliable animal model of Eustachian Tube obstruction to further research into middle ear disorders. Study designProspective cohort study in animals. SettingUniversity laboratory. Subjects and methods30 mice C57Bl/6J (n = 15) and CBA/CaJ (n = 15) aged 6–8 weeks received transtympanic Eustachian tube occlusion on left ear trough an acute tympanic membrane perforation using thermoplastic latex used in dental procedures (gutta percha). Control mice (n = 6) received tympanic membrane perforation only. At two and four weeks, the mice were observed for signs of Eustachian tube dysfunction and compared to control ears. ET dysfunction was defined as presence of effusion in the middle ear. Results100% (n = 30) of the treated ears had otoscopic signs of Eustachian tube dysfunction at two weeks and the endpoint time of four weeks, compared to 0% in control mice (0/6). Temporary head tilt lasting up to 2 days were observed in 3 mice (10%). No other potential adverse events were recorded. No bacterial growth was determined in the middle ear fluid. ConclusionWe describe a technically easy and reliable method for Eustachian tube occlusion in mice with an excellent success rate and minimal morbidity.

Esterified Hyaluronic Acid Placed in the Middle Ear Does Not Improve Outcomes in Cholesteatoma Surgery.

Background: The aim of this article is to assess the efficacy of esterified hyaluronic acid as a barrier to formation of adhesions and improvement of tympanomastoid ventilation.METHODS: A prospective cohort analysis was performed at a tertiary referral centre. 126 ears were analysed in children with cholesteatoma. Esterified hyaluronic acid was placed on the promontory of 63 ears at primary canal wall intact surgery for cholesteatoma. No esterified hyaluronic acid was used in 63 control ears. Cholesteatoma recurrence, histopathological analysis of scar tissue following second-stage procedure, and middle ear pressure were the main outcome measures.Results: At 5 years, esterified hyaluronic acid (7%) and non-esterified hyaluronic acid (10%) did not differ in cholesteatoma recurrence (Kaplan– Meier log rank analysis, P = .52). Esterified hyaluronic acid (n = 11) and non-esterified hyaluronic acid (n = 2) ears formed scar at the site of packing material (n = 11) (Fisher’s exact test, P = .04). Foamy histiocytes/macrophages were found in esterified hyaluronic acid (n = 15) and non-esterified hyaluronic acid ears (n = 1) (Fisher’s exact test, P < .001). Middle ear pressure was measurable in 32/43 (74%) esterified hyaluronic acid ears and 36/52 (69%) non-esterified hyaluronic acid ears (P = .58, chi-square test). Median post-operative middle ear pressure in esterified hyaluronic acid (– 115.0 daPa) and non-esterified hyaluronic acid ears (– 85 daPa) did not differ significantly (Mann–Whitney U-test, – 30.0 daPa, P = .33). Middle ear pressure was normal (> – 125 daPa) in 44% (14/32) esterified hyaluronic acid ears and 42% (15/36) non-esterified hyaluronic acid ears (P = 1.0, Fisher’s exact test).Conclusions: We have discontinued the use of esterified hyaluronic acid in cholesteatoma surgery due to lack of detectable benefit. Esterified hyaluronic acid in the middle ear neither reduces cholesteatoma recurrence nor appears to improve the ventilation of the middle ear. Furthermore, esterified hyaluronic acid alters the inflammatory process within the middle ear, the significance of which remains unclear.

Partial reproduction of ear-tip necrosis suggests an infectious, initially bacterial aetiology

Swine ear-tip necrosis (ETN) is a disease of global presence and unclear aetiology. Little evidence is available regarding the nature of this disease. The aim of this work was to investigate if ETN is an infectious disease that could be replicated using a lesion macerate inoculum.A source farm with a history of ear-tip necrosis was identified and five weeks-old pigs (n = 12) from this farm were housed under controlled conditions and intradermally inoculated with ETN lesion macerates (right ear, n = 10) or sterile inoculum (left ear, n = 10). Two pigs were not inoculated, serving as sentinels. All animals were clinically monitored daily during 21 days, and a ETN ear score was used to follow disease progression. Anaerobic (n = 2) and aerobic (n = 2) overnight cultures, as well as raw aliquots of the lesion macerate inoculum (n = 2) and control inoculum (n = 2) were submitted for metagenomic sequencing. All inoculated ears developed lesions suggestive of early ETN, but none progressed to result in loss of the ear pinna. All completely resolved 21 days post-inoculation. Post-mortem investigation revealed areas of fibrosis, characterized by a granulomatous response in the inoculated ears (5/10) and in 1/10 control ears. Metagenomic analysis identified the presence of previously suggested bacterial etiological agents, but no relevant viral, fungal or protozoan agents in the inoculum. ETN etiology remains unclear, but an infectious cause and bacterial agents are suggested to be at least partially implicated in disease pathogenesis. Virus and fungi do not seem to significantly contribute to disease.

Histopathologic Analysis of Temporal Bones With Otosclerosis Following Cochlear Implantation.

Analyze changes in osteoneogenesis and fibrosis following cochlear implant (CI) surgery in patients with otosclerosis and compare differences based on insertion technique. When advanced otosclerotic disease extends to the otic capsule, severe and profound sensorineural hearing loss necessitates consideration of a cochlear implant. Histopathological analysis of the human temporal bone after implantation in the patient with otosclerosis may reveal important variables that predict CI success. Histopathological evaluation of archival human temporal bones from subjects with a history of CI for cochlear otosclerosis. A total of 17 human temporal bones (HTB) were analyzed, 13 implanted, and 4 contralateral non-implanted controls. Histopathological studies revealed extensive osteoneogenesis and fibrosis which was more prominent at the cochleostomy insertion site in the basal turn of the cochlea often obliterating the scala tympani in the basal turn, and in some cases extending to the scala media and scala vestibuli. Cochlear hydrops was nearly universal in these cases. This contrasted with the round window insertion, which exhibited minimal osteoneogenesis within the cochlear duct. In addition, in the contralateral, unimplanted control ears, there was otosclerosis at the stapes footplate, fissula ante fenestrum but no osteoneogenesis within the cochlear duct. Cochleostomy approach to CI insertion in otosclerosis patients is associated with significant fibrosis, osteoneogenesis, and cochlear hydrops. A round window insertion technique can be utilized to help minimize these histopathologic findings whenever feasible.

High-resolution computational modeling of the current flow in the outer ear during transcutaneous auricular Vagus Nerve Stimulation (taVNS)

BackgroundTranscutaneous auricular Vagus Nerve Stimulation (taVNS) applies low-intensity electrical current to the ear with the intention of activating the auricular branch of the Vagus nerve. The sensitivity and selectivity of stimulation applied to the ear depends on current flow pattern produced by a given electrode montage (size and placement). ObjectiveWe compare different electrodes designs for taVNS considering both the predicted peak electric fields (sensitivity) and their spatial distribution (selectivity). MethodsBased on optimized high-resolution (0.47 mm) T1 and T2 weighted MRI, we developed an anatomical model of the left ear and the surrounding head tissues including brain, CSF/meninges, skull, muscle, blood vessels, fat, cartilage, and skin. The ear was further segmented into 6 regions of interest (ROI) based on various nerve densities: cavum concha, cymba concha, crus of helix, tragus, antitragus, and earlobe. A range of taVNS electrode montages were reproduced spanning varied electrodes sizes and placements over the tragus, cymba concha, earlobe, cavum concha, and crus of helix. Electric field across the ear (from superficial skin to cartilage) for each montage at 1 mA or 2 mA taVNS, assuming an activation threshold of 6.15 V/m, 12.3 V/m or 24.6 V/m was predicted using a Finite element method (FEM). Finally, considering every ROI, we calculated the sensitivity and selectivity of each montage. ResultsCurrent flow patterns through the ear were highly specific to the electrode montage. Electric field was maximal at the ear regions directly under the electrodes, and for a given total current, increases with decreasing electrode size. Depending on the applied current and nerves threshold, activation may also occur in the regions between multiple anterior surface electrodes. Each considered montage was selective for one or two regions of interest. For example, electrodes across the tragus restricted significant electric field to the tragus. Stimulation across the earlobe restricted significant electric field to the earlobe and the antitragus. Because of this relative selectivity, use of control ear montages in experimental studies, support testing of targeting. Relative targeting was robust across assumptions of activation threshold and tissue properties. DiscussionComputational models provide additional insight on how details in electrode shape and placement impact sensitivity (how much current is needed) and selectivity (spatial distribution), thereby supporting analysis of existing approaches and optimization of new devices. Our result suggest taVNS current patterns and relative target are robust across individuals, though (variance in) axon morphology was not represented.

Mechanics of Total Drum Replacement Tympanoplasty Studied With Wideband Acoustic Immittance.

Poor hearing outcomes often persist following total drum replacement tympanoplasty. To understand the mechanics of the reconstructed eardrum, we measured wideband acoustic immittance and compared the mechanical characteristics of fascia-grafted ears with the normal tympanic membrane. Prospective comparison study. Tertiary care center. Patients who underwent uncomplicated total drum replacement with temporalis fascia grafts were identified. Ears with healed grafts, an aerated middle ear, and no other conductive abnormalities were included. All patients underwent pre- and postoperative audiometry. Wideband acoustic immittance was measured with absorbance and impedance computed. Fascia-grafted ears were compared with normal unoperated ears. Eleven fascia-grafted ears without complications were included. Postoperatively, the median air-bone gap was 15 dB (250-4000 Hz), with variation across frequency and between ears. Fifty-six control ears were included. Absorbance of fascia-grafted ears was significantly lower than that of normal ears at 1 to 4 kHz (P < .05) but similar below 1 kHz. Impedance magnitude demonstrated deeper and sharper resonant notches in fascia-grafted ears than normal ears (P < .05), suggesting lower mechanical resistance of the fascia graft. The mechanics of fascia-grafted ears differ from the normal tympanic membrane by having lower absorbance at mid- to high frequencies and thus poor sound transmission. The lower resistance in fascia-grafted ears may be due to poor coupling of the graft to the malleus. To improve sound transmission, grafts for tympanic membrane reconstructions would benefit from refined mechanical properties.

Improving the Differential Diagnosis of Otitis Media With Effusion Using Wideband Acoustic Immittance.

The objective of this work is to determine whether there is a systematic effect of middle ear effusion volume on wideband acoustic immittance in children with surgically confirmed otitis media with effusion. Wideband acoustic immittance was measured in 49 ears from children (9 months to 11 years) who had a diagnosis of otitis media with effusion and compared to 14 ears from children (10 months to 10 years) without a recent history of otitis media. For children with otitis media with effusion, wideband acoustic immittance testing took place in the child's preoperative waiting room before surgical placement of tympanostomy tubes. Testing was completed in a pressurized condition (wideband tympanometry) for all ears as well as in an ambient condition in a subset of ears. Intraoperative findings regarding effusion volume were reported by the surgeons immediately before tube placement and confirmed following myringotomy. This classified the volume of effusion as compared to middle ear volume categorically as either full, partial, or clear of effusion. The type of wideband acoustic immittance explored in this work was absorbance. Absorbance responses were grouped based on effusion volume into one of four groups: full effusions, partial effusions, ears clear of effusion at the time of surgery, and normal control ears. Standard tympanometry was also completed on all ears. Absorbance is systematically reduced as the volume of the middle ear effusion increases. This reduction is present at most frequencies but is greatest in the frequency range from 1 to 5 kHz. A multivariate logistic regression approach was utilized to classify ears based on effusion volume. The regression approach classified ears as effusion present (full and partial ears) or absent (clear ears and normal control ears) with 100% accuracy, ears with effusion present as either partial or full with 100% accuracy, and ears without effusion as either normal control ears or ears clear of effusion with 75% accuracy. Regression performance was also explored when the dataset was split into a training set (70% of the data) and a validation test set (30% of the data) to simulate how this approach would perform on unseen data in a clinical setting. Accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve are reported. Overall, this approach demonstrates high sensitivity and specificity for classifying ears as effusion being present or absent and as present effusions being full or partial with areas under the curve ranging from 1 to 0.944. Despite the lack of effusion present in both clear ears and normal control ears, this approach was able to distinguish between these ears, but with a more moderate sensitivity and specificity. No systematic effect of effusion volume was found on standard tympanometry. Wideband acoustic immittance, and more specifically, absorbance, is a strong and sensitive indicator of the volume of a middle ear effusion in children with otitis media with effusion.

Audiologic Profiles of Children With Otitis Media With Effusion.

To describe the impact of effusion volume, viscosity, and purulence on the audiologic profiles of children with otitis media with effusion. Fifty-one ears from children between the ages of 8 months and 11 years who had a diagnosis of otitis media with effusion and were scheduled for tympanostomy tube placement were recruited from medical clinics. The control group consisted of 17 ears from children between the ages of 10 months and 11 years without a recent history of otitis media and were recruited from a database of research volunteers. Participants received a comprehensive audiologic testing battery consisting of tympanometry, otoacoustic emissions, behavioral audiometric thresholds, and auditory brainstem response testing. For children with otitis media, this testing battery occurred 1 to 2 days before surgery. Middle ear effusions were characterized and collected on the day of surgery during tympanostomy tube placement from ears with otitis media with effusion. The comprehensive audiologic testing battery was completed postoperatively as well for most participants. Effusion volume, categorized in each ear as clear, partial, or full, effected the audiologic results. Ears with full effusions had moderate hearing losses, few to no measurable otoacoustic emissions, and delayed Wave V latencies. Ears with partial effusions and clear ears both had slight to mild hearing losses and normal Wave V latencies, though ears with partial effusions had fewer measurable otoacoustic emissions than clear ears. Normal-hearing control ears with no recent history of otitis media with effusion demonstrated normal audiometric thresholds, present otoacoustic emissions, and normal Wave V latencies. Repeat postoperative testing demonstrated improvements in audiologic testing results for all of the otitis media with effusion volume groups, with no significant differences remaining between the three otitis media with effusion groups. However, significant differences between otitis media with effusion ears and normal-hearing control ears persisted postoperatively, with otitis media with effusion ears demonstrating significantly poorer audiometric thresholds and reduced otoacoustic emissions as compared to normal control ears. The effect of effusion viscosity and purulence could not be systematically evaluated because minimal variability in effusion viscosity and purulence was observed in our sample, with nearly all effusions being mucoid and nonpurulent. Effusion volume observed at the time of tympanostomy tube surgery was found to play a significant role in outcomes and responses on a range of audiologic tests that compose the standard clinical pediatric audiologic assessment battery. Full middle ear effusions were associated with a moderate hearing loss, and few to no measurable otoacoustic emissions were detected. Ears with a recent diagnosis of otitis media with effusion but clear at the time of tympanostomy tube placement had less hearing loss and a greater number of present otoacoustic emissions than ears with full or partial effusions but were still found to have poorer hearing sensitivity than the healthy control ears. Differences between ears with otitis media with effusion and healthy control ears persisted on postoperative assessments of otoacoustic emissions and audiometric thresholds, though there were no remaining effects of the presurgical effusion volume group.

CT Assessment of Otic Capsule Bone Density in Paget's Disease of the Temporal Bone and Its Relationship With Hearing Loss.

To study computed tomography findings in Paget's disease of temporal bone (PDTB) and analyze the relations between otic capsule bone mineral density values measured in Hounsfield Units (HU) and hearing loss (HL). Observational case-control study. Tertiary referral center. Radiographically confirmed PDTB cases and control group. Diagnostic. Hearing thresholds and computed tomography bone density values. Twenty-three ears in the case group (PDTB) and 27 control ears were included. In the PDTB group, HL was found in 87% of the ears (43% mixed) and an air-conduction threshold of 50.7 dB (SD = 19.8). In the control group, 48% of the ears showed HL (7% mixed) and an air-conduction threshold of 34.5 dB (SD = 20.6) was found; the difference was statistically significant (p < 0.05). Measurements of bone density (HU) in the otic capsule (regions of interest [ROI] 1 and 2) and in the petrous bone (ROI 3) were significantly lower (p < 0.05) in the PDTB group than in controls.The PDTB group presented a significant association between otic capsule bone density in ROI 1 and mean otic capsule density with air and bone-conduction thresholds (p < 0.05). In controls, no association was observed between any density value and audiometric thresholds. PDTB patients showed more frequent HL, lower thresholds, and a higher proportion of mixed HL than controls. Bone density (HU) was decreased in all ROIs in PDTB patients in comparison with controls. Bone density in the otic capsule was associated with HL in PDTB patients, but no association was observed between bone density and HL in controls.