Thomas Wesarg

Comparison of pseudobinaural hearing to real binaural hearing rehabilitation after cochlear implantation in patients with unilateral deafness and tinnitus.

Objective: Up to now, treatment modalities of unilateral deafness consist of no treatment, conventional contralateral routing of signal (CROS), or Bone-Anchored Hearing Aid (BAHA) hearing aid. Cochlear implantation makes a new treatment modality available for patients with single-sided deafness. The aim of this study is to evaluate the use of unilateral electrical stimulation with normal hearing on the contralateral side after a period of 6 months compared with the preoperative unaided situation, conventional CROS, or BAHA hearing aids. Study Design: Prospective design. Setting: Tertiary referral center; cochlear implant (CI) program. Patients: Eleven adult subjects with unilateral deafness of various causes were enrolled in the study. Only those patients were included in whom therapy with CROS hearing aid or BAHA was not successful and in whom the auditory nerve was found to be intact and the cochlea patent for cochlear implantation. Intervention: All subjects were fitted in random order with a BAHA Intenso mounted on the softband/tension clamp or with a CROS hearing aid. After test periods with both devices, the subjects received a CI. Main Outcome Measures: The Hochmair-Schulz-Moser sentence test and the Oldenburg sentence test were used to test speech comprehension in 3 presentation configurations in the unaided situation, with conventional CROS and BAHA hearing aids before cochlear implantation as well as after 6 months with CI. Localization was assessed using an array of 7 speakers at head level in a frontal semicircle. Subjective improvement in daily life was evaluated using the Speech, Spatial and Qualities of Hearing Scale, the Health Utilities Index 3 and the International Outcome Inventory for Hearing Aids questionnaires. Tinnitus distress was measured with a tinnitus scale before and after CI implantation. Results: The results show significant improvement in localization ability as well as in speech comprehension in most presentation configurations with the CI. Especially, there is no negative effect on speech comprehension if the noise is presented to the CI ear and speech to the normal hearing ear. With the CI, the summation and squelch effects are not significant, but a significant combined head shadow effect is seen. Speech, Spatial and Qualities of Hearing results show an overall benefit of wearing the CI compared with the other treatment options. The tinnitus scale revealed a positive effect of CI stimulation in cases of preoperative tinnitus. Conclusion: The results in these patients suggest that cochlear implantation improves hearing abilities in people with single-sided deafness and is superior to the alternative treatment options. The use of the CI does not interfere with speech understanding in the normal hearing ear. Our data suggest that the binaural integration of electric and acoustic stimulation is possible even with unilateral normal hearing.

The benefits of sequential bilateral cochlear implantation for hearing-impaired children

Conclusion. Sequential bilateral implantation offers listening advantages demonstrable on speech recognition in noise and for lateralization. Whilst the trend was for shorter inter-implant intervals and longer implant experience to positively impact binaural advantage, we observed no contraindications for binaural advantage. Objective. To evaluate the benefits of sequential bilateral cochlear implantation over unilateral implantation in a multicentre study evaluating speech recognition in noise and lateralization of sound. Subjects and methods. Twenty children, implanted bilaterally in sequential procedures, had the following characteristics: they were native German-speaking, were3 years or older and had a minimum of 1 year inter-implant interval and had between 2 months and 4 years 7 months binaural listening experience. Binaural advantage was assessed including speech recognition in noise using the Regensburg modification of the Oldenburger Kinder-Reimtest (OLKI) and lateralization of broadband stimuli from three speakers. Results. A significant binaural advantage of 37% was observed for speech recognition in noise. Binaural lateralization ability was statistically superior for the first and second implanted ear (p=0.009, p=0.001, respectively). Binaural experience was shown to correlate moderately with absolute binaural speech recognition scores, with binaural advantage for speech recognition and with binaural lateralization ability. The time interval between implants correlated in an inverse direction with binaural advantage for speech recognition.

Unilateral deafness in children: audiologic and subjective assessment of hearing ability after cochlear implantation.

Objectives Recently, several studies have shown that a cochlear implant is a suitable treatment for hearing rehabilitation of adults with unilateral sensorineural hearing loss (UHL), and benefits for speech comprehension in noise and localization have been demonstrated. The aim of this clinical study was to evaluate the benefit of cochlear implantation in children with UHL in comparison to their unaided listening situation. Study design Prospective repeated measures single subject design. Setting Tertiary referral center; cochlear implant (CI) program Patients Three children (4, 10, and 11 yr) with noncongenital UHL resulting from different causes were enrolled in the study. Intervention After extensive consultation with each family and confirming CI-candidacy, each child received a cochlear implant. Main Outcome Measures Open set speech recognition measures in competing background noise and tests of sound localization were performed for unaided preoperative and CI-aided postimplant intervals after 6 and 12 months. The parent and child versions of the Speech, Spatial and Qualities scale (SSQ) were used for subjective evaluation of hearing at preimplant and 12-month postimplant intervals. Conclusion All children consistently use their CI 1 year postimplant. Our preliminary results suggest binaural hearing benefits for speech understanding in noise, localization ability and subjectively perceived hearing ability for school-aged children with UHL. Trends for CI-benefits in younger preschoolaged children are confirmed through subjective assessment reported by the parents. The benefits in hearing performance suggest binaural integration and processing of electric and acoustic stimulation arriving at 2 different ears is possible for children with UHL.

Clinical results of AutoNRT, a completely automatic ECAP recording system for cochlear implants.

Objective: AutoNRT™ is the completely automatic electrically evoked compound action potential (ECAP) measuring algorithm in the recently released Nucleus Freedom cochlear implant system. AutoNRT allows clinicians to automatically record T-NRT profiles that in turn can be used as a guide for initial fitting. The algorithm consists of a pattern recognition part that judges if the traces contain an ECAP and an intelligent flow that optimizes the measurement parameters and finds the ECAP threshold (T-NRT). The objective of this study was to determine how accurate, reliable, and fast the automatic measurements are. Design: Data on more than 400 electrodes were collected as part of the multicenter clinical trial of the Nucleus Freedom cochlear implant system. T-NRT values determined by the algorithm were compared with T-NRT determinations on the same data by different human observers. Also, the time the measurements took was analyzed. Results: In 90% of the cases, the absolute difference between the AutoNRT and the human observer determined T-NRT was less than 9 CL; the median absolute difference was 3 CL. A second experiment, in which a group of human observers were asked to analyze NRT data, showed high variability in T-NRT; in some cases, two experienced clinicians disagreed by more than 30 current levels. Compared with the group, AutoNRT performed as well as the “average” clinician, with the advantage that the AutoNRT threshold determinations are objective. Analysis of the timing data showed an average intraoperative measurement time of less than 20 sec per electrode with a standard deviation of 5 sec, suggesting that the total array of 22 electrodes can be measured intraoperatively in about 7 minutes on average. Conclusions: AutoNRT provides comparable accuracy to an average clinician but with the added benefit of significant time savings over manual recordings. This makes it a valuable tool for clinical measurement of ECAP threshold in cochlear implant recipients.

Cochlear Implantation in Children with Single-Sided Deafness: Does Aetiology and Duration of Deafness Matter?

For adult patients with single-sided deafness (SSD), treatment with a cochlear implant (CI) is well established as an acceptable and beneficial hearing rehabilitation method administered routinely in clinical practice. In contrast, for children with SSD, CI has been applied less often to date, with the rationale to decide either on a case-by-case basis or under the realm of clinical research. The aim of our clinical study was to evaluate the longitudinal benefits of CI for a group of children diagnosed with SSD and to compare their outcomes with respect to patient characteristics. Evaluating a pool of paediatric SSD patients presenting for possible CI surgery revealed that the primary aetiology of deafness was congenital cochlear nerve deficiency. A subgroup of children meeting the CI candidacy criteria for the affected ear (the majority with acquired hearing loss) were enrolled in the study. Preliminary group results suggest substantial improvements in speech comprehension in noise and in the ability to localise sound, which was demonstrated through objective and subjective assessments after CI treatment for the group, with results varying from patient to patient. Our study shows a trend towards superior outcomes for children with acquired hearing loss and a shorter duration of hearing loss compared to congenitally deafened children who had a longer duration of SSD. This indicates an interactive influence of the age at onset, aetiology and duration of deafness upon the restoration of binaural integration and the overall benefits of sound stimulation to two ears after CI treatment. Continued longitudinal investigation of these children and further studies in larger groups may provide more guidance on the optimal timing of treatment for paediatric patients with acquired and congenital SSD.

Cochlear Implant Programming: A Global Survey on the State of the Art

The programming of CIs is essential for good performance. However, no Good Clinical Practice guidelines exist. This paper reports on the results of an inventory of the current practice worldwide. A questionnaire was distributed to 47 CI centers. They follow 47600 recipients in 17 countries and 5 continents. The results were discussed during a debate. Sixty-two percent of the results were verified through individual interviews during the following months. Most centers (72%) participated in a cross-sectional study logging 5 consecutive fitting sessions in 5 different recipients. Data indicate that general practice starts with a single switch-on session, followed by three monthly sessions, three quarterly sessions, and then annual sessions, all containing one hour of programming and testing. The main focus lies on setting maximum and, to a lesser extent, minimum current levels per electrode. These levels are often determined on a few electrodes and then extrapolated. They are mainly based on subjective loudness perception by the CI user and, to a lesser extent, on pure tone and speech audiometry. Objective measures play a small role as indication of the global MAP profile. Other MAP parameters are rarely modified. Measurable targets are only defined for pure tone audiometry. Huge variation exists between centers on all aspects of the fitting practice.

Spectrum of hearing disorders and their management in children with CHARGE syndrome.

Objective: The CHARGE syndrome is associated with ear anomalies and deafness in addition to other malformations. Deformations of the ossicles or aplasia of the semicircular canals, cochlear hypoplasia, hypoplasia or aplasia of the VIIIth cranial nerve and abnormal routing of the VIIth cranial nerve, sigmoid sinus, and emissaries are typical findings. The aim of this study is to explore the feasibility and procedure of cochlear implantation in patients with CHARGE syndrome and to assess the outcome. Study Design: Retrospective case review. Setting: Tertiary referral center; cochlear implant program. Patients: Ten patients with CHARGE syndrome and 3 patients with CHARGE-like syndrome treated in our center due to hearing impairment. Eleven patients were congenitally deaf, 1 patient had progressive hearing loss, and 1 patient had mixed hearing loss. Intervention: Computed tomography of temporal bones and magnetic resonance imaging of the brain; bone-anchored hearing aid surgery, cochlear implantation, rehabilitation results. Main Outcome Measures: Surgical suitability and hearing rehabilitation. Results: We illustrate the management of preoperative diagnostics, surgical planning, and hearing rehabilitation. One patient with mixed hearing loss underwent bilateral bone-anchored hearing aid surgery. Because 2 patients had bilateral aplasia of the auditory nerves, we recommended an auditory brainstem implant. The unilateral cochlear implantation was performed in 9 patients and bilateral in 1 patient. In selected cases, it was helpful to plan the operation using a simulator for temporal bone surgery. Complex malformations, such as in CHARGE syndrome, with an increased intraoperative risk for complications should be facilitated by using intraoperative digital volume tomography-assisted navigation and intraoperative digital volume tomography control of electrode position. The results after CI surgery vary due to the differing extent of additional disabilities such as developmental delay, intellectual delay, and visual impairment. Nine of our patients showed improved responsiveness with the cochlear implant. Open speech comprehension could not be observed in 8 patients, whereas the follow-up period was less than 1 year in 4 patients. The relatively high age of our patients at implantation might be an important factor. Conclusion: Careful planning of the treatment of CHARGE syndrome patients with sensorineural hearing loss can, to a limited extent, lead to auditory benefit without increasing surgical complications. Cochlear implantation is therefore indicated after critical assessment.

Radiologically assisted navigation in cochlear implantation for X-linked deafness malformation

Abstract The X-linked deafness syndrome is characterised by a complex labyrinth malformation with a shortened cochlea with missing bony separation between the cochlea and internal auditory canal and a deviant route of the facial nerve. Cochlear implant surgery in this malformation may be complicated by an unintended electrode insertion into the internal auditory canal. The authors report a new surgical approach: intraoperative three dimensional-volume tomography (3D-VT)-based navigation and direct intraoperative control by 3D-VT. The navigation dataset was based on intraoperative 3D-VT after performing the mastoidectomy and posterior tympanotomy. The cochleostomy was then performed under navigation control. After insertion, the electrode position was directly visualised by 3D-VT. On the basis of the reconstruction results, the electrode position was corrected and an intracochlear insertion resulted. Cochlear implantation in X-linked deafness malformation can be facilitated using intraoperative 3D-VT-assisted navigation and intraoperative 3D-VT control of the electrode position. This approach enhances the precision of navigation and reduces the risk of improper electrode placement and additional surgery in complex malformations. Copyright

Clinical outcome after cochlear implantation in patients with unilateral hearing loss due to labyrinthitis ossificans.

Objectives Cochlear implantation (CI) is the treatment of choice in bilateral labyrinthitis ossificans (LO). The aim of this clinical case study was to evaluate audiologic and subjective outcomes after CI treatment for unilateral hearing loss (UHL) because of LO and to identify optimal timing for treatment. Patients Three subjects (age 40, 54, and 68 yr) with UHL because of LO were enrolled. Duration of deafness was 1.5, 12, and 120 months. Intervention After extensive consultation, testing with conventional contralateral routing of signal hearing aid and bone-anchored hearing instrument, CI candidacy was confirmed and CI surgery performed. Main Outcome Measures Test of open-set speech recognition in background noise and sound localization were performed preoperatively, in unaided and aided conditions, and in the CI-aided condition, at 6 and 12 months postoperatively. Subjective assessment via the Speech, Spatial and Qualities scale (SSQ) and the Tinnitus Visual Analogue Scale was performed at preimplant and 12 months postimplant. Conclusion The data show moderate-to-high hearing benefit after CI in 2 cases and no benefit for the third. SSQ and tinnitus scales show benefit from CI use in both cases. CI treatment should be performed as early as possible, ideally before signs of obliteration are evident. Counseling on all rehabilitation options is important.

Kochleaimplantat bei Innenohrfehlbildungen

The radiologic evaluation of the temporal bone in cochlear implant candidates can detect malformations of the inner ear in up to 20% of cases. The aim of our study was to analyze and classify malformations of the inner ear in patients with cochlear implants carried out from 2001 to 2009. Malformations of the inner ear, including malformations of the internal auditory canal were detected in 12.7% of children and 3.4% of adults. Mondini dysplasia was most common and occurred in 45% of cases. The surgical procedure had to be adapted according to the individual malformation. Modification of surgical access, management of intraoperative CSF gusher, choice of electrode array, intraoperative imaging and the use of navigation were the most important factors. Rehabilitation results were generally very positive and corresponded to the expectation depending on the duration of deafness, if no additional handicaps were present.ZusammenfassungDie radiologische Evaluation des Felsenbeins bei Kochleaimplantat-Voruntersuchungen deckt in bis zu 20% der Fälle Fehlbildungen des Innenohrs auf. Ziel der vorgelegten Untersuchung war die retrospektive Analyse und Klassifikation der mit einem Kochleaimplantat versorgten Patienten mit einer Innenohrfehlbildung an der Universitäts-HNO-Klinik Freiburg im Zeitraum 2001–2009. Dabei wurden Fehlbildungen des Innenohrs einschließlich der Dysplasien des inneren Gehörgangs bei Kindern in 12,7% und bei Erwachsenen in 3,4% der Fälle gefunden. Mondini-Dysplasien wurden mit 45% am häufigsten beobachtet. Das chirurgische Vorgehen wurde adaptiert, entsprechend der jeweiligen Fehlbildung. Von Bedeutung sind dabei die Modifikation des operativen Zugangs, das Management des intraoperativen Gusher, die Auswahl der zu implantierenden Elektrode, die intraoperative Bildgebung sowie der Einsatz der Navigation. Die postoperativen Ergebnisse sind als sehr positiv zu bewerten und entsprechen der Erwartung in Abhängigkeit von der Dauer der Taubheit, wenn keine zusätzlichen Entwicklungsbehinderungen bestehen.AbstractThe radiologic evaluation of the temporal bone in cochlear implant candidates can detect malformations of the inner ear in up to 20% of cases. The aim of our study was to analyze and classify malformations of the inner ear in patients with cochlear implants carried out from 2001 to 2009. Malformations of the inner ear, including malformations of the internal auditory canal were detected in 12.7% of children and 3.4% of adults. Mondini dysplasia was most common and occurred in 45% of cases. The surgical procedure had to be adapted according to the individual malformation. Modification of surgical access, management of intraoperative CSF gusher, choice of electrode array, intraoperative imaging and the use of navigation were the most important factors. Rehabilitation results were generally very positive and corresponded to the expectation depending on the duration of deafness, if no additional handicaps were present.