Does Intraoperative Extracochlear Electrocochleography Correlate With Postoperative Audiometric Hearing Thresholds in Cochlear Implant Surgery? A Retrospective Analysis of Cochlear Monitoring.

In recent years, tools for early detection of irreversible trauma to the basilar membrane during hearing preservation cochlear implant (CI) surgery were established in several clinics. A link with the degree of postoperative hearing preservation in patients was investigated, but patient populations were usually small. Therefore, this study's aim was to analyze data from intraoperative extracochlear electrocochleography (ECochG) recordings for a larger group.During hearing preservation CI surgery, extracochlear recordings were made before, during, and after CI electrode insertion using a cotton wick electrode placed at the promontory. Before and after insertion, amplitudes and stimulus response thresholds were recorded at 250, 500, and 1000 Hz. During insertion, response amplitudes were recorded at one frequency and one stimulus level. Data from 121 patient ears were analyzed.The key benefit of extracochlear recordings is that they can be performed before, during, and after CI electrode insertion. However, extracochlear ECochG threshold changes before and after CI insertion were relatively small and did not independently correlate well with hearing preservation, although at 250 Hz they added some significant information. Some tendencies-although no significant relationships-were detected between amplitude behavior and hearing preservation. Rising amplitudes seem favorable and falling amplitudes disadvantageous, but constant amplitudes do not appear to allow stringent predictions.Extracochlear ECochG measurements seem to only partially realize expected benefits. The questions now are: do gains justify the effort, and do other procedures or possible combinations lead to greater benefits for patients?

Short-term safety and effectiveness of the mCLIP partial prosthesis.

PURPOSE: This multicentric, retrospective study aimed to analyze the short-term safety and effectiveness of the mCLIP Partial Prosthesis. METHODS: Patients underwent tympanoplasty with implantation of a mCLIP Partial Prosthesis. Follow-up examination included ear microscopy and pure-tone audiometry to determine the post-operative pure tone average of the frequencies 0.5, 1, 2 and 3 kHz (PTA4). The post-operative PTA4 air bone gap (ABG) was used to evaluate the audiological outcome. A post-operative minimum and maximum follow-up period was not defined. Thus, the follow-up times of each study center were different, which resulted in different follow-up times for the audiological analysis and for adverse events (AE). RESULTS: 72 (66 adults, 6 children) patients were implanted with the mCLIP Partial Prosthesis. 68 (62 adults, 6 children) patients underwent audiological examination; all 72 patients were examined for adverse events. All patients (N = 68): 72.1% of the patients showed a PTA4 ABG of ≤ 20 dB. Individual post-operative bone conduction (BC) PTA4 thresholds were stable in 67 patients. The mean post-operative follow-up time was 78 ± 46 days. Children (N = 6): 5 out of 6 children showed a PTA4 ABG of ≤ 20 dB. None of the children reported a BC PTA4 deterioration of > 10 dB HL after the implantation. The mean post-operative follow-up time was 101 ± 45 days. Adverse events (all patients, N = 72): 15 (14 adults, 1 child) patients had AEs (27 AEs and 2 Follow-Ups). The mean post-operative follow-up time was 375 days. CONCLUSION: Clinical data show satisfactory audiological parameters after implantation of the mCLIP Partial Prosthesis. The prosthesis is safe and effective for implantation in children and adults. TRIAL REGISTRATION NUMBER: NCT05565339, 09 September 2022, retrospectively registered.

Comparison of superelastic nitinol stapes prostheses and platin teflon stapes prostheses.

INTRODUCTION: Stapes plasty is an established procedure to improve hearing in case of otosclerosis. By reinforcing the prostheses, an optimization of the prosthesis could be achieved. The aim of the study was to evaluate the audiological results of the Nitinol Superelastic stapes prosthesis compared with a Platin-Teflon prosthesis. MATERIAL AND METHODS: In a retrospecitve setting, the audiological results of nine patients who have been implanted with a Nitinol Alloy Superelastic stapes prothesis were compared with the results of ten patients, which have been implanted with a Platinum-Teflon piston prostesis. All operations were performed by the same experienced ear surgeon. RESULTS: The Nitinol-group presented an average of postoperative air-bone-gap over all frequencies (0.5-6 kHz) of all patients of 15.1 dB. In the Platin-Teflon group, the average of postoperative air-bone-gap was 14.9 dB. Moreover, the post surgery delta-bone-conduction pre- to post surgery showed no differences (0.5-6 kHz). There were no surgical complications in both groups. CONCLUSION: Based on the patient collective, stapes plasty using a Nitinol Superelastic stapes prosthesis is a sufficient method for improving the hearing conduction. DESIGN: Retrospective case series. SETTING: University Department.

Preliminary Study on Antinuclear Antibodies in Patients With Chronic Dilatory Eustachian Tube Dysfunction.

BACKGROUND AND HYPOTHESIS: There are some known reasons for chronic dilatory Eustachian tube dysfunction (chronic D-ETD, also known as chronic obstructive tube dysfunction), for example infections, hyperplastic adenoids, or tumors. In many cases though, none of these reasons apply. The question arises whether there might be an autoimmune pathogenesis in patients with idiopathic chronic D-ETD. METHODS: The study includes 31 consecutive patients with chronic D-ETD and 92 consecutive blood donors (BD, comparative cohort). The production of antinuclear antibodies (ANA), as an indicator for autoimmune pathologies, was measured in the serum of patients and BD. RESULTS: ANA titers were significantly higher in patients with chronic D-ETD, compared with BD (p = 0.0027). The results weighted clearly toward higher ANA titers in younger patients. A comparison of ANA titers in patients and BD aged less than 40 years showed a significant difference (p = 0.0062), whereas it was not significant between patients and BD aged ≥ 40 years (p = 0.19). CONCLUSION: The significant results of elevated ANA titers in chronic D-ETD make an autoimmune pathogenesis highly probable, at least in some of the patients concerned. Further research with higher numbers of patients is needed to confirm the hypothesis of an autoimmune chronic D-ETD. A better understanding of etiology and pathogenesis of chronic D-ETD might open up new and perhaps even causal therapeutic strategies.

Cochlear Implantation in Organ Transplant Recipients.

OBJECTIVE: Immunosuppressed individuals who have undergone organ transplants, especially children, pose particular challenges in terms of treatment. The aim of this study was to analyze the postoperative complication rate of organ transplant recipients who have also received a cochlear implant (CI). STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. INTERVENTION: The case series includes 13 kidney, liver, lung, and heart transplant patients. Age at treatment ranged from 2 to 71 years, with a total of 17 CIs. MAIN OUTCOME MEASURES: Postoperative complications were classified into major and minor, early (within 3 mo postoperatively) and late (>3 mo postoperatively). The results were compared with those for 13 1:1 matched pairs obtained and from our database and a healthy patient collective from our department. RESULTS: The global postoperative complication rate was 29.4%. The proportion of patients suffering major complications was 17.6%, with 17.6% having minor complications. Complications that occurred early accounted for 13.3%, and late for 26.7%. No adults, and 33.0% of children, showed any complications after cochlear implantation. The global complication rate (29.4%) was significantly increased compared with the matched pairs (0%, p = 0.013) and department data (13.8%, p = 0.006; Cramers v = 0.102). CONCLUSION: This study demonstrates that organ transplant recipients, and especially children, are at increased risk of postoperative complications after cochlear implantation in comparison with healthy CI recipients.

Evidence and evidence gaps in the treatment of Eustachian tube dysfunction and otitis media.

Evidence-based medicine is an approach to medical treatment intended to optimize patient-oriented decision-making on the basis of empirically proven effectiveness. For this purpose, a classification system has been established to categorize studies - and hence therapy options - in respect of associated evidence according to defined criteria. The Eustachian tube connects the nasopharynx with the middle ear cavity. Its key function is to ensure middle ear ventilation. Compromised ventilation results in inflammatory middle ear disorders. Numerous evidence-based therapy options are available for the treatment of impaired middle ear ventilation and otitis media, the main therapeutic approach being antibiotic treatment. More recent procedures such as balloon dilation of the Eustachian tube have also shown initial success but must undergo further evaluation with regard to evidence. There is, as yet, no evidence for some of the other long-established procedures. Owing to the multitude of variables, the classification of evidence levels for various treatment approaches calls for highly diversified assessment. Numerous evidence-based studies are therefore necessary in order to evaluate the evidence pertaining to existing and future therapy solutions for impaired middle ear ventilation and otitis media. If this need is addressed, a wealth of implications can be expected for therapeutic approaches in the years to come.

Radiologic detectability of the cochlear implant electrode fixation clip using cone beam computed tomography.

INTRODUCTION: With the aim of preventing migration of cochlear implantation electrodes in the postoperative course, an electrode fixation clip has been developed. It is characterized by two clips of double U-geometry. The bone fixation clip will be clamped on the bony incus bridge, and the electrode fixation clip is clamped to the electrode lead. Although made of titanium, the detectability in radiologic imaging appears limited. MATERIALS AND METHODS: Six patients, who received a cochlear implant between August 2014 and March 2015, were retrospectively analyzed for the detectability of the Med-El Electrode Fixation Clip in postoperative cone beam CT scans. For these patients, we randomly extracted appropriate control group patients without implanted clips (matched pairs). One instructed neuro-radiologist blindly evaluated postoperative radiographs on a visual, descriptive basis of both groups with the main outcome measure of clip detectability. RESULTS: In total, images of 12 patients were evaluated. In five of the six (83%) study group patients, the clip was detected radiologically correct. One patient (17%) was appointed as false negative. All patients (100%) without a clip were correctly identified. DISCUSSION: The electrode fixation clip can be identified, despite its small size, using cone beam CT. Sensitivity and specificity are high. This aspect assumes importance especially in postoperative monitoring, e.g. in cases of revision surgery. Thus, this study contributes to the overall safety in cochlear implant surgery.

Facial palsy following cochlear implantation.

Owing to its anatomical location, the facial nerve (FN) is at risk of damage during cochlear implantation, especially during posterior tympanotomy. The aim of this study was, therefore, to evaluate the risk of FN palsy following cochlear implantation surgery via mastoidectomy and posterior tympanotomy approach (facial recess). This is a retrospective study. The data bank of patients who received a cochlear implant between 2000 and 2012 was analyzed. 3403 surgeries were done during this period. Records of the patients who had suffered from FN palsy were evaluated and the type of FN palsy, the severity, time of onset, and need for revision surgery were recorded. 0.76 % (26/3403) of the patients had FN palsy and were, therefore, included in the study. 76.9 % (20/26) subjects were 18 years or older. 0.15 % (5 subjects) suffered from immediate FN palsy and 0.62 % (21 subjects) from delayed FN palsy. Intraoperative FN injury was documented in only three subjects of the immediate FN palsy group. In two subjects with immediate FN palsy, the FN was intraoperatively exposed but not injured, despite these individuals' experiencing FN palsy. In 100 % of the immediate onset FN palsy group a part of the FN was exposed during surgery, whereas it was exposed only in 9.5 % of the delay onset FN palsy group. Although the FN was bone protected in 19 subjects, they had FN palsy. Most of the subjects presented House-Brackmann grade III or IV (69.2 %). All of the subjects were treated initially with a conservative therapy, only 42.3 % (11 subjects) underwent revision surgery. The recovery rate was 80.8 % (in immediate onset palsy 40 %, in delayed onset palsy 90.5 %). Cochlear implantation entails only a minimal risk of FN palsy and that FN palsy is chiefly a transient problem.

Effects of Signal-to-Noise Ratio on Auditory Cortical Frequency Processing.

The neural mechanisms that support the robust processing of acoustic signals in the presence of background noise in the auditory system remain largely unresolved. Psychophysical experiments have shown that signal detection is influenced by the signal-to-noise ratio (SNR) and the overall stimulus level, but this relationship has not been fully characterized. We evaluated the neural representation of frequency in rat primary auditory cortex by constructing tonal frequency response areas (FRAs) in primary auditory cortex for different SNRs, tone levels, and noise levels. We show that response strength and selectivity for frequency and sound level depend on interactions between SNRs and tone levels. At low SNRs, jointly increasing the tone and noise levels reduced firing rates and narrowed FRA bandwidths; at higher SNRs, however, increasing the tone and noise levels increased firing rates and expanded bandwidths, as is usually seen for FRAs obtained without background noise. These changes in frequency and intensity tuning decreased tone level and tone frequency discriminability at low SNRs. By contrast, neither response onset latencies nor noise-driven steady-state firing rates meaningfully interacted with SNRs or overall sound levels. Speech detection performance in humans was also shown to depend on the interaction between overall sound level and SNR. Together, these results indicate that signal processing difficulties imposed by high noise levels are quite general and suggest that the neurophysiological changes we see for simple sounds generalize to more complex stimuli. SIGNIFICANCE STATEMENT: Effective processing of sounds in background noise is an important feature of the mammalian auditory system and a necessary feature for successful hearing in many listening conditions. Even mild hearing loss strongly affects this ability in humans, seriously degrading the ability to communicate. The mechanisms involved in achieving high performance in background noise are not well understood. We investigated the effects of SNR and overall stimulus level on the frequency tuning of neurons in rat primary auditory cortex. We found that the effects of noise on frequency selectivity are not determined solely by the SNR but depend also on the levels of the foreground tones and background noise. These observations can lead to improvement in therapeutic approaches for hearing-impaired patients.

Subtotal petrosectomy and Codacs™: new possibilities in ears with chronic infection.

Subtotal petrosectomy combined with obliteration of the tympanomastoid is a standard procedure to treat temporal bones in patients with radical cavity and chronic infections. Currently, patients with profound-to-severe sensorineural hearing loss are often fitted with cochlear implants. In the case of profound mixed hearing loss, active middle ear implants have been used successfully. The new Codacs™ system provides an effective treatment for patients with severe-to-profound mixed hearing loss; however, only aerated middle ears have been treated with this device. The question arises whether the Codacs™ can be implanted in patients with radical cavity or ears with chronic otorrhea. Of the 41 patients who were implanted with the Codacs™ at the department, 4 received the device after subtotal petrosectomy and obliteration with abdominal fat. Clinical and audiological results were assessed. The device was implanted without any complications in the obliterated subtotal petrosectomy. The preliminary results of the first two patients showed stable bone conduction thresholds and indicated improved speech intelligibility in quiet and noise. Implanting the Codacs™ device after subtotal petrosectomy and obliteration with abdominal fat has been proven to be a feasible and suitable procedure for patients with radical cavity or chronic otorrhea. The speech intelligibility outcome directly after activation was comparable to patients with aerated middle ears.

Impact of Elevation of Temporal Lobe During Middle Fossa Acoustic Neuroma Surgery on Contralateral Speech Discrimination.

AIM: For middle fossa acoustic neuroma approach, retractors are needed to elevate the temporal lobe to be able to access the internal auditory meatus. The temporal lobe hosts the primary and secondary auditory fields. The question arises regarding whether this elevation affects the functionality of the auditory cortex. MATERIAL AND METHODS: In patients, who underwent acoustic neuroma surgery, contralateral speech discrimination was tested pre- and postsurgery using different speech discrimination tests. Results of patients with a middle fossa approach were compared with patients with a translabyrinthine approach. RESULTS: No major differences between the translabyrinthine and the middle fossa approach could be detected. CONCLUSION: Elevation of the temporal lobe during middle fossa approach for acoustic neuroma surgery does not lead to short-term impaired contralateral speech discrimination compared with translabyrinthine approach.

Comparison of two different titanium couplers for an active middle ear implant.

OBJECTIVE: To compare surgical methods, functional gain, and speech discrimination using two different coupling methods for an active middle ear implant. Of several couplers enabling placement of the active element at various locations, two function directly at a cochlear membrane, bypassing a missing or malformed ossicular chain. This study evaluates whether either of these methods is more beneficial. STUDY DESIGN: Retrospective case review. SETTING: ENT surgical clinic. PATIENTS: Forty-seven German-speaking patients with moderate to severe mixed hearing loss. INTERVENTIONS: Records of patients implanted with either a round window (RW) or oval window (OW) coupler and active implant were examined. Preoperative and postoperative bone and air-conduction thresholds, auditory gain, and speech perception were compared. MAIN OUTCOME MEASURES: Functional gain, Freiburger monosyllables in quiet. RESULTS: The range of hearing benefit shown by functional gain in patients implanted with the RW coupler (median) was between 22.5 dB (at 0.25 kHz) and 52.5 dB (2 and 3 kHz). In the OW group, improvement was similar, ranging from 21 dB (at 8 kHz) to 50 dB (1 and 2 kHz). Patients in both groups showed a similar improvement in speech recognition. Median preoperative unaided word recognition was 0% at 60 dB HL for both patient groups, improved postoperatively in both groups to median 85% correct at 65 dB HL and 95% at 80 dB HL. CONCLUSION: Placement of an active middle ear implant using the RW and the OW coupler was found to be safe, although the surgical methods differ. Safety and efficacy of both couplers present no significant differences.

Outer ear canal infection with Rhabditis sp. nematodes in a human.

Here we report the first human case of an outer ear canal infection with a free-living nematode of the genus Rhabditis. Otomicroscopy revealed viable worms in the outer ear canal of a patient suffering from chronic otorrhea and hearing loss. The nematode was identified by microscopy and internal transcribed spacer (ITS)-PCR.

Do we really need a Coupler for the round window application of an AMEI?

OBJECTIVE: Implanting active middle ear implants (AMEI) at the round window has become a standard procedure to restore hearing for patients with moderate inner ear or mixed hearing loss. The round window (RW)-Coupler was developed as an alternative coupling aid to fit smaller RW diameters and require less drilling in the RW niche. The question arises whether using the RW-Coupler is useful and a safe procedure compared with the nonuse of the RW-Coupler MATERIALS AND METHODS: Forty-nine German-speaking patients were implanted with either a RW-Coupler attached to an AMEI floating mass transducer (FMT) or without coupler. They were evaluated preoperatively and postoperatively for bone and air conduction thresholds with and without the implant, as well as speech perception tests. RESULTS: Bone conduction thresholds remained stable preoperatively and postoperatively. The patient's functional gain was slightly better with the RW-Coupler. Focusing on the average speech perception performances, both groups presented an improvement of speech perception above 80% at 65 dB HL. CONCLUSION: RW-Coupler-Vibroplasty was found to be a safe procedure, which produced good results in this group of patients with mixed hearing loss.

New HRCT-based measurement of the human outer ear canal as a basis for acoustical methods.

PURPOSE: As the form and size of the external auditory canal determine its transmitting function and hence the sound pressure in front of the eardrum, it is important to understand its anatomy in order to develop, optimize, and compare acoustical methods. METHOD: High-resolution computed tomography (HRCT) data were measured retrospectively for 100 patients who had received a cochlear implant. In order to visualize the anatomy of the auditory canal, its length, radius, and the angle at which it runs were determined for the patients' right and left ears. The canal's volume was calculated, and a radius function was created. RESULTS: The determined length of the auditory canal averaged 23.6 mm for the right ear and 23.5 mm for the left ear. The calculated auditory canal volume (Vtotal) was 0.7 ml for the right ear and 0.69 ml for the left ear. The auditory canal was found to be significantly longer in men than in women, and the volume greater. CONCLUSION: The values obtained can be employed to develop a method that represents the shape of the auditory canal as accurately as possible to allow the best possible outcomes for hearing aid fitting.

Cochlear implantation in different health-care systems: disparities between Germany and the United States.

INTRODUCTION: Cochlear implantation is a popular procedure to restore hearing in patients with severe-to-profound hearing loss. Despite the widespread acceptance of the intervention, many variables exist in the evaluation for and implementation of this technology throughout the world. The primary aim of this investigation is to analyze treatment disparities between Germany and the United States in cochlear implantation. MATERIALS AND METHODS: Cochlear implant recipients in 2 representative cochlear implant centers in the United States and Germany were retrospectively analyzed. Differences in preoperative, perioperative, and postoperative treatment paradigms as well as the disparities in the follow-up were recorded. Objective measures included demographic data, length of hospitalization, minor and major complication rates, and speech scores within the first 3 years. Moreover, a cost analysis comparison between both centers was performed. RESULTS: A number of differences in treatment were noted between the two centers. The primary difference was that in Germany the procedure was inpatient with an average 4-day hospital stay, whereas in the United States, it was an outpatient procedure. Despite these differences, only small differences were noted in the category of minor complications, and no differences were seen in the category of major complications between the 2 centers. Comparing the results of monosyllabic speech tests, no major differences could be detected. Cost analysis between the 2 centers demonstrates that, whereas in Germany, all charges are covered by the statutory health insurance, in the United States, the reimbursements are significantly lower than the charges. DISCUSSION: Despite differences in the clinical approach to cochlear implants in Germany versus the United States, no significant differences in outcomes were seen in the 2 groups, and the complication rates were nearly identical. Interestingly, although the procedure in Germany is associated with a 4-day hospital stay, the charges for the entire procedure in Germany are approximately ½ as compared with those in the United States, although the actual reimbursement for this procedure may be lower in the United States than in Germany.

The influence of post-meningitic obliteration and ossification of the cochlea on cochlear microphonics.

Cochlear microphonics are electrical stimulus responses of the inner ear. They are generated by mechanical displacement of the hair cells caused by acoustic stimulation and can be recorded from the cochlear promontory via a needle electrode. In individuals with post-meningitic deafness, fibrous obliteration or ossification of the cochlea may occur. The aim of the present investigation was to establish whether obliteration or ossification leads to any alteration in the extent to which cochlear microphonics can be recorded (as compared with that in patients with a fluid-filled cochlea whose deafness was not post-meningitic), as an indication of changes in the mechanical displacement of the remaining hair cells. Cochlear microphonics in 15 individuals with proven obliteration or ossification of the cochlea were compared with those in 15 control subjects (deaf individuals whose hearing loss was not post-meningitic, and who had a fluid-filled cochlea). Our findings reveal no statistically significant differences between the two groups in the degree to which cochlear microphonics can be recorded. This study does not demonstrate evidence of a change in this property due to ossification or obliteration of the cochlea.

"Minimized rotational vestibular testing" as a screening procedure detecting vestibular areflexy in deaf children: screening cochlear implant candidates for Usher syndrome type I.

Morbus Usher (USH), a combination of sensorineural hearing loss and retinal visual impairment, is classified into group I-III. USH I patients are born deaf. Within the first 10 years of life, they develop a severe vision impairment due to progressive retinal dystrophy (retinitis pigmentosa). USH I patients show vestibular deficits. The incidence of USH I among congenitally deaf children is assumed to be as high as 10%. We intend to create a simple examination procedure for screening congenitally deaf children for vestibular deficiency and subsequently USH I. The examination procedure is named "Minimized Rotation". The vestibular function of deaf children was examined by Minimized Rotation during their preoperative cochlear implant candidacy examination. A lack of postrotational nystagmus was seen as an indication for vestibular deficit. Subsequently some of these patients were examined under general anaesthesia by electroretinography (ERG) at the Department of Ophthalmology. A total of 117 children were examined by Minimized Rotation. In 19 children (16.2%) no rotational nystagmus was found. Six of these children were additionally examined at the Department of Ophthalmology using Ganzfeld ERG. Three of them (50%) showed generalized dysfunction of the retina; 8.1% of the children undergoing preoperative evaluation for cochlear implatation are assumed to show abnormalities of the retina. Rotational examination seems to be an appropriate screening method to detect vestibular deficits, which is one sign of USH I. The results always have to be verified by Ganzfeld-ERG or further genetic investigations. Children with USH I are threatened by progressive reduction of vision. We, therefore, consider USH I children always to be implanted bilaterally with a cochlear implant to maximize the benefit of auditory rehabilitation.

The use of buccal smears for a non-invasive screening of the 35delG mutation of the Connexin-26 gene in hearing impaired young children.

OBJECTIVES: Recent advances in genetic research indicate that about 50% of congenital deaf patients have a genetic background, with mutations in the Connexin-26 gene being the most frequent one. Screening methods for the genetic cause of deafness have so far mostly been based on the use of peripheral whole blood as DNA source. The use of buccal smears for the genetic screening of deaf patients presents an interesting alternative to drawing blood, especially in young children. In order to validate this method, we compared results from buccal smears from very young deaf children (age