Influence of inner ear impedance on middle ear sound transfer functions.

Introduction: For experimental studies on sound transfer in the middle ear, it may be advantageous to perform the measurements without the inner ear. In this case, it is important to know the influence of inner ear impedance on the middle ear transfer function (METF). Previous studies provide contradictory results in this regard. With the current study, we investigate the influence of inner ear impedance in more detail and find possible reasons for deviations in the previous studies. Methods: 11 fresh frozen temporal bones were prepared in our study. The factors related to inner ear impedance, including round window membrane stiffness, cochleostomy, cochlea fluid and cochlea destruction were involved in the experimental design. After measuring in the intact specimen as a reference (step 1), the round window membrane was punctured (step 2), then completely removed (step 3). The cochleostomy was performed (step 4) before the cochlear fluid was carefully suctioned through scala tympani (step 5) and scala vestibuli (step 6). Finally, cochlea was destroyed by drilling (step 7). Translational and rotational movement of the stapes footplate were measured and calculated at each step. The results of the steps were compared to quantify the effect of inner ear impedance changing related to the process of cochlear drainage. Results: As the inner ear impedance decreases from step 1 to 7, the amplitudes of the METF curves at each frequency gradually increase in general. From step 6 on, the measured METF are significantly different with respect to the intact group at high frequencies above 3 kHz. The differences are frequency dependent. However, the significant decrement of rotational motion appears at the frequencies above 4.5 kHz from the step 5. Conclusion: This study confirms the influence of inner ear impedance on METF only at higher frequencies (≥3 kHz). The rotational motions are more sensitive to the drainage of fluid at the higher frequency. Study results that found no influence of cochlea impedance may be due to incomplete drainage of the cochlea.

Visualization of bone formation in sheep's middle ear by using fluorochrome sequential labelling (FSL).

One factor for the lacking integration of the middle ear stapes footplate prosthesis or the missing healing of stapes footplate fractures could be the known osteogenic inactivity. In contrast, it was recently demonstrated that titanium prostheses with an applied collagen matrix and immobilised growth factors stimulate osteoblastic activation and differentiation on the stapes footplate. Regarding those findings, the aim of this study was to evaluate the potential of bone regeneration including bone remodeling in the middle ear. Ten one-year-old female merino sheep underwent a middle ear surgery without implantation of middle ear prostheses or any other component for activating bone formation. Post-operatively, four fluorochromes (tetracycline, alizarin complexion, calcein green and xylenol orange) were administered by subcutaneous injection at different time points after surgery (1 day: tetracycline, 7 days: alizarin, 14 days: calcein, 28 days: xylenol). After 12 weeks, the temporal bones including the lateral skull base were extracted and histologically analyzed. Fluorescence microscopy analysis of the entire stapes with the oval niche, but in particular stapes footplate and the Crura stapedis revealed evidence of new bone formation. Calcein was detected in all and xylenol in 60% of the animals. In contrast, tetracycline and alizarin could only be verified in two animals. The authors were able to demonstrate the osseoregenerative potential of the middle ear, in particular of the stapes footplate, using fluorescence sequence labelling.

Influence of cochlear implantation on the working ability of hearing-impaired patients: A prospective study on potential influencing factors.

PURPOSE: This study evaluates the effect of cochlear implantation (CI) on work ability. The influences of quality of life (QOL), age, mental health, and hearing were analyzed. METHODS: Seventy-nine patients undergoing CI surgery were evaluated preoperatively and 12 months postoperatively. Work ability was evaluated using the Work Ability Index (WAI). QOL was assessed with the Nijmegen Cochlear Implant Questionnaire (NCIQ) and the WHOQOL-BREF. Mental health was assessed with the Patient Health Questionnaire. RESULTS: The WAI was unaffected by CI (Δ 0.8 ± 6.8, p = 0.42). No significant changes in WAI were observed for employees (Δ - 1.1 ± 5.7, p = 0.25) and pensioners (Δ -0.4 ± 7.8, p = 0.73). Patients without elevated depressiveness, stress, or somatoform symptoms had significantly better WAI.The multiple regression analyses show that WHOQOL-BREF (ß = 0.49, p ≤ 0.001), age (ß = -0.34, p ≤ 0.001), and depressiveness (ß = 0.33, p = 0.04) were significantly associated with WAI. In the employee group, the NCIQ (ß = 0.58, p = 0.008) had the strongest association with the WAI. CONCLUSION: Age, mental health, and QOL are predictive factors for work ability. This should be considered in the consultation and the rehabilitation process.

The Dresden in vivo OCT dataset for automatic middle ear segmentation.

Endoscopic optical coherence tomography (OCT) offers a non-invasive approach to perform the morphological and functional assessment of the middle ear in vivo. However, interpreting such OCT images is challenging and time-consuming due to the shadowing of preceding structures. Deep neural networks have emerged as a promising tool to enhance this process in multiple aspects, including segmentation, classification, and registration. Nevertheless, the scarcity of annotated datasets of OCT middle ear images poses a significant hurdle to the performance of neural networks. We introduce the Dresden in vivo OCT Dataset of the Middle Ear (DIOME) featuring 43 OCT volumes from both healthy and pathological middle ears of 29 subjects. DIOME provides semantic segmentations of five crucial anatomical structures (tympanic membrane, malleus, incus, stapes and promontory), and sparse landmarks delineating the salient features of the structures. The availability of these data facilitates the training and evaluation of algorithms regarding various analysis tasks with middle ear OCT images, e.g. diagnostics.

High-Dose Glucocorticoids for the Treatment of Sudden Hearing Loss.

BACKGROUND: Systemic glucocorticoids are commonly used for primary therapy of idiopathic sudden sensorineural hearing loss (ISSNHL). However, the comparative effectiveness and risk profiles of high-dose over lower-dose regimens remain unknown. METHODS: We randomly assigned patients with sudden hearing loss of greater than or equal to 50 dB within 7 days from onset to receive either 5 days of high-dose intravenous prednisolone at 250 mg/d (HD-Pred), 5 days of high-dose oral dexamethasone at 40 mg/d (HD-Dex), or, as a control, 5 days of oral prednisolone (Pred-Control) at 60 mg/d followed by 5 days of tapering doses. The primary outcome was the change in hearing threshold (pure tone average) in the three most affected contiguous frequencies from baseline to day 30. Secondary outcomes included speech understanding, tinnitus, communication competence, quality of life, hypertension, and insulin resistance. RESULTS: A total of 325 patients were randomly assigned. Mean change in 3PTAmost affected hearing threshold from baseline to 30 days was 34.2 dB (95% CI, 28.4 to 40.0) in the HD-Pred group, 41.4 dB (95% CI, 35.6 to 47.2) in the HD-Dex group, and 41.0 dB (95% CI, 35.2 to 46.8) in the Pred-Control group (P=0.09 for analysis of variance). There were more adverse events related to trial medication in the HD-Pred (n=73) and HD-Dex (n=76) groups than in the Pred-Control group (n=46). CONCLUSIONS: Systemic high-dose glucocorticoid therapy was not superior to a lower-dose regimen in patients with ISSNHL, and it was associated with a higher risk of side effects. (Funded by the Federal Ministry of Education and Research [BMBF]; EudraCT number, 2015­002602­36.)

In Vivo Thickness of the Healthy Tympanic Membrane Determined by Optical Coherence Tomography.

OBJECTIVE: Tympanic membrane (TM) thickness is an important parameter for differentiation between a healthy and a pathologic TM. Furthermore, it is needed for modeling the middle ear function. Endoscopic optical coherence tomography (eOCT) provides the opportunity to measure the TM thickness of the entire TM in vivo. MATERIALS AND METHODS: A total of 27 healthy ears were examined by eOCT. The system uses a light source with a central wavelength of 1,300 nm. The endoscope with an outer diameter of 3.5 mm provides a field of view of 10 mm and a working distance of 10 mm. Thickness measurements were carried out at 8 points on the TM. Additionally, the existing literature was analyzed, and a mean TM thickness value was determined. RESULTS: The mean thickness of the TM over all measurement points of the pars tensa was 120.2 µm, and the pars flaccida was significantly thicker with a mean thickness of 177.9 µm. Beyond that, there were no significant differences between the single quadrants. The mean TM thickness in the literature was 88.8 µm. DISCUSSION: EOCT provides the possibility for in vivo thickness determination of the TM. The mean thickness seems to be higher than in the previous studies, which were mostly carried out ex vivo. Our study takes the three-dimensional refraction into account and provides a method for the refraction correction.

[Interprofessional evaluation of "soft skills" of students in the practical year]. / Interprofessionelle Evaluation der "Soft Skills" von Studierenden des Praktischen Jahres.

OBJECTIVE: The present study deals with the implementation of a questionnaire with 360° evaluation to assess the performance of students in the practical year (PJ). A special focus is put on the "soft skills" (self-competence, methodological competence, social competence), whose evaluation in medical studies has not yet taken place comprehensively. MATERIAL & METHODS: The study was conducted prospectively with 21 PJ students of the Medical Faculty of the TU Dresden. The assessment was performed by means of a self-designed questionnaire, which was divided into 4 sub-competencies (self-competence, methodological competence, social competence, clinical skills and abilities), which could be assessed by means of a 6-point Likert scale. Four professions were involved in the assessment: Medical Service, Nursing Service, Functional Service, and Administration. RESULTS: On average, the strongest deficits in terms of self-confidence, willingness to perform, and ability to deal with conflict were revealed by students in the PJ. Students showed a very good performance in performing a medical history and basic skills of clinical examination. CONCLUSION: The implementation of 360° feedback is possible and useful for students in the internship year across disciplines and professions. Such personal and interprofessional feedback has not been widely available. The questionnaire represents the first comprehensive measurement tool of soft skills for medical students and provides a good basis for comprehensive feedback.

Effect of Cochlear Implant Electrode Insertion Depth on Speech Perception Outcomes: A Systematic Review.

Objective: The suitable electrode array choice is broadly discussed in cochlear implantation surgery. Whether to use a shorter electrode length under the aim of structure preservation versus choosing a longer array to achieve a greater cochlear coverage is a matter of debate. The aim of this review is to identify the impact of the insertion depth of a cochlear implant (CI) electrode array on CI users' speech perception outcomes. Databases Reviewed: PubMed was searched for English-language articles that were published in a peer-reviewed journal from 1997 to 2022. Methods: A systematic electronic search of the literature was carried out using PubMed to find relevant literature on the impact of insertion depth on speech perception. The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses guidelines of reporting. Studies in both, children and adults with pre- or postlingual hearing loss, implanted with a CI were included in this study. Articles written in languages other than English, literature reviews, meta-analyses, animal studies, histopathological studies, or studies pertaining exclusively to imaging modalities without reporting correlations between insertion depth and speech outcomes were excluded. The risk of bias was determined using the "Risk of Bias in Nonrandomized Studies of Interventions" tool. Articles were extracted by 2 authors independently using predefined search terms. The titles and abstracts were screened manually to identify studies that potentially meet the inclusion criteria. The extracted information included: the study population, type of hearing loss, outcomes reported, devices used, speech perception outcomes, insertion depth (linear insertion depth and/or the angular insertion depth), and correlation between insertion depth and the speech perception outcomes. Results: A total of 215 relevant studies were assessed for eligibility. Twenty-three studies met the inclusion criteria and were analyzed further. Seven studies found no significant correlation between insertion depth and speech perception outcomes. Fifteen found either a significant positive correlation or a positive effect between insertion depth and speech perception. Only 1 study found a significant negative correlation between insertion depth and speech perception outcomes. Conclusion: Although most studies reported a positive effect of insertion depth on speech perception outcomes, one-third of the identified studies reported no correlation. Thus, the insertion depth must be considered as a contributing factor to speech perception rather than as a major decisive criterion. Registration: This review has been registered in PROSPERO, the international prospective register of systematic reviews (CRD42021257547), available at https://www.crd.york.ac.uk/PROSPERO/.

Word Recognition with a Cochlear Implant in Relation to Prediction and Electrode Position.

BACKGROUND: the word recognition score (WRS) achieved with cochlear implants (CIs) varies widely. To account for this, a predictive model was developed based on patients' age and their pre-operative WRS. This retrospective study aimed to find out whether the insertion depth of the nucleus lateral-wall electrode arrays contributes to the deviation of the CI-achieved WRS from the predicted WRS. MATERIALS AND METHODS: patients with a pre-operative maximum WRS > 0 or a pure-tone audiogram ≥80 dB were included. The insertion depth was determined via digital volume tomography. RESULTS: fifty-three patients met the inclusion criteria. The median WRS achieved with the CI was 70%. The comparison of pre- and post-operative scores achieved with a hearing aid and a CI respectively in the aided condition showed a median improvement of 65 percentage points (pp). A total of 90% of the patients improved by at least 20 pp. The majority of patients reached or exceeded the prediction, with a median absolute error of 11 pp. No significant correlation was found between the deviation from the predicted WRS and the insertion depth. CONCLUSIONS: our data support a previously published model for the prediction of the WRS after cochlear implantation. For the lateral-wall electrode arrays evaluated, the insertion depth did not influence the WRS with a CI.