Rainer Beck

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.

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.

The new mid-scala electrode array: a radiologic and histologic study in human temporal bones.

Hypothesis To analyze the quality of insertion of the newly developed midscala (MS) electrode, which targets a midscalar electrode position to reduce the risk of trauma to the lateral wall and the modiolus. Background Modern cochlear implant surgery aims for a safe intracochlear placement of electrode arrays with an ongoing debate regarding cochleostomy or round window (RW) insertion and the use of lateral wall or perimodiolar electrode placement. Intracochlear trauma after insertion of different electrodes depends on insertion mode and electrode design and may result in trauma to the delicate structures of the cochlear. Methods We performed a temporal bone (TB) trial with insertion of the MS electrode in n = 20 TB‘s after a mastoidectomy and posterior tympanotomy. Insertion was performed either via the RW or a cochleostomy. Electrode positioning, length of insertion, and angle of insertion were analyzed with rotational tomography (RT). TBs were histologically analyzed. Results of RT and histology were compared. Results Scala tympani (ST) insertion could be accomplished reliably by both RW and via a cochleostomy approach. In 20 TBs, 1 scala vestibuli insertion, 1 incomplete (ST), and 1 elevation of basilar membrane were depicted. No trauma was found in 94.7% of all ST insertions. RT allowed determination of the intracochlear electrode position, which was specified by histologic sectioning. Conclusion The new MS electrode seems to fulfill reliable atraumatic intracochlear placement via RW and cochleostomy approaches. RT is available for evaluation of intracochlear electrode position, serving as a potential quality control instrument in human implantation.

Revision surgery due to magnet dislocation in cochlear implant patients: an emerging complication.

Objectives To analyze the cause and effect of magnet dislocation in cochlear implant (CI) recipients requiring magnet revision surgery for treatment. Study Design Retrospective study. Setting Tertiary referral center. Interventions Case reports from 1,706 CI recipients consecutively implanted from January 2000 to December 2011 were reviewed. The number of cases requiring magnet revision surgery was assessed. Results Revision surgery involving magnet removal or replacement was indicated in 1.23% (21/1,706), of all CI recipients. Magnet dislocation occurring during magnetic resonance tomography (MRI), at 1.5 Tesla (T), with the magnet in place and with the application of compression bandaging around the head, was the main cause for revision surgery in 47.62% (10/21) of the affected cases. All 10 cases were implanted with Cochlear Nucleus cochlear implants. These events occurred, despite adherence to current recommendations of the manufacturer. Conclusion The present study underlines that MRI examination is the main cause of magnet dislocation. The use of compressive bandaging when using 1.5-T MRI does not eliminate the risk of magnet dislocation. Additional cautionary measures are for required for conditional MRI. We recommend X-ray examination after MRI to determine magnet dislocation and avoid major complications in all cases reporting pain during or after MRI. Additional research regarding silicon magnet pocket design for added retention is needed. Effective communication of guidelines for precautionary measures during MRI examination in CI patients is mandatory for all clinicians involved. MRI in CI recipients should be indicated with caution.

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.

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.

A novel dominant and a de novo mutation in the GJB2 gene (connexin-26) cause keratitis-ichthyosis-deafness syndrome: implication for cochlear implantation.

Objective: Keratitis-ichthyosis-deafness (KID) syndrome is a rare congenital disorder, characterized by hyperkeratosis and erythrokeratoderma associated with profound sensorineural hearing loss. Additional concomitant phenomena of the KID syndrome are dystrophic nails, dental abnormalities, scarring alopecia, and vascularizing keratitis. The disorder is caused by mutation in the GJB2 gene (connexin-26), a gap junction protein. The aim of this study was to explore the feasibility and procedure of cochlear implantation in patients with KID syndrome and to assess the genetic causes. Study Design: Retrospective case review. Setting: Tertiary referral center. Cochlear implant program. Patients: We report on 2 cases of KID syndrome with congenital profound hearing loss. A 50-year-old woman with skin necrosis and implant extrusion 5 years after cochlear implantation and a 10-month-old infant girl with bilateral deafness, alopecia, bright light sensitivity, and congenital dermatosis. Intervention: Genetic analysis. Cochlear implantation. Main Outcome Measures: Mutation analysis, surgical suitability, and hearing rehabilitation. Results: We detected a novel heterozygous missense mutation (Ile30Asn) in Patient 1 and a de novo mutation (Asp50Asn) in the GJB2 gene (connexin-26) in Patient 2. To decrease the risk of skin flap necrosis, we describe alternative surgical cochlear implantation techniques with a novel very thin receiver/stimulator (Nucleus CI 513; Cochlear Corp.). The postoperative course of both patients has been without any problems until now. Conclusion: The combination of the cutaneous lesions with visual and auditory impairment demands to diagnose impaired hearing as early as possible. It would be helpful to search for KID syndrome in dealing with patients with deafness, skin lesions of unknown cause, and wound healing problems to choose the right method of surgical treatment and subsequent aftercare.

Radiologic Results and Hearing Preservation With a Straight Narrow Electrode via Round Window Versus Cochleostomy Approach at Initial Activation.

Objective To evaluate the potential influence of two different cochlear implant (CI) electrode carrier approaches to the scala tympani in terms of insertion depth and angle as well as hearing preservation. Study Design Retrospective follow-up study. Setting Tertiary care academic center. Patients Forty-one adult subjects underwent cochlear implantation using the Cochlear Nucleus CI 422 slim straight electrode (Cochlear Limited, New South Wales, Australia) with the intent of achieving atraumatic electrode insertion and hearing preservation. Interventions Fourteen subjects were implanted using a cochleostomy approach and 27 via a round window approach. Main Outcome Measures Radiologic assessment of insertion depth and angle was performed on postoperative rotational tomography. Postoperative low-frequency hearing preservation, complete loss of residual low-frequency hearing, and speech perception in quiet measures were obtained in defined intervals for both groups. Results Mean insertion depth reached 21.5 mm (standard deviation, 1.1), whereas mean insertion angle of 388 degrees (standard deviation, 34.7) was revealed for all CI recipients, with no significant difference between the cochleostomy cohort and the round window cohort. The CI-aided speech perception in quiet showed significantly higher scores 3 to 4 months after activation compared with the preoperative speech perception results. The audiologic data demonstrated no statistically significant difference in probability of complete loss of residual low-frequency hearing at initial activation between the cochleostomy group and the round window group. Conclusion The present results suggest that similar insertion depth and angle as well as similar low-frequency hearing preservation can be achieved in cochlear implantation with this straight narrow electrode via either cochleostomy approach or round window approach at least at initial activation. This fact gives the surgeon the opportunity to adapt access to the scala tympani as needed.

Comparison of speech discrimination in noise and directional hearing with 2 different sound processors of a bone-anchored hearing system in adults with unilateral severe or profound sensorineural hearing loss.

Objective To evaluate and compare the benefit of a bone-anchored hearing implant with 2 different sound processors in adult patients with unilateral severe to profound sensorineural hearing loss (UHL). Study Design Prospective crossover design. Setting Tertiary referral center. Patients Eleven adults with UHL and normal hearing in the contralateral ear were assigned to 2 groups. Intervention All subjects were unilaterally implanted with a bone-anchored hearing implant and were initially fitted with 2 different sound processors (SP-1 and SP-2). SP-1 is a multichannel device equipped with an omnidirectional microphone and relatively simple digital signal-processing technology and provides a user-adjustable overall gain and tone control with compression limiting. SP-2 is a fully channel-by-channel programmable device, which can be set with nonlinear dynamic range compression or linear amplification. In addition, SP-2 features automatic noise management, an automatic multichannel directional microphone, microphone position compensation, and an implementation of prescription rules for different types of hearing losses, one of them unilateral deafness. After at least 1-month use of the initial processor, both groups were fitted with the alternative processor. Main Outcome Measures Speech discrimination in noise and localization tests were performed at baseline visit before surgery, after at least 1-month use of the initial processor, and after at least 2-week use of the alternative processor. Results Relative to unaided baseline, SP-2 enabled significantly better overall speech discrimination results, whereas there was no overall improvement with SP-1. There was no difference in speech discrimination between SP-1 and SP-2 in all spatial settings. Sound localization was comparably poor at baseline and with both processors but significantly better than chance level for all 3 conditions. Conclusion Patients with UHL have an overall objective benefit for speech discrimination in noise using a bone-anchored hearing implant with SP-2. In contrast, there is no overall objective benefit from SP-1. Depending on the speech-in-noise presentation setting, the difference between objective benefit from SP-2 and SP-1 might be mainly attributed to the new technological features in SP-2 unavailable in SP-1 such as 1) automatic noise management reducing the noise in the speech signal and thus improving the signal-to-noise ratio of the resulting signal on the better ear, 2) programmable multichannel sound-processing and nonlinear dynamic range compression offering considerably greater control over signal amplification compared to SP-1, and 3) implementation of a prescription rule for unilateral deafness addressing the specific amplification needs of patients with UHL by reducing amplification in the low frequencies and applying additional gain in the high frequencies. Sound localization is poor but better than chance level in the unaided condition as well as in both bone-anchored hearing system–aided conditions.

Cochlear Implantation in Children With Congenital Unilateral Deafness: A Case Series

OBJECTIVES Cochlear implant is regarded as a treatment option for hearing rehabilitation of adults with unilateral sensorineural hearing loss. A clear benefit has been experienced in regard to speech comprehension in noise, localization, and quality of life. The aim of this study was to investigate the benefit of cochlear implantation for children with congenital unilateral hearing loss. STUDY DESIGN Retrospective case series. SETTING Tertiary referral center; cochlear implant program. PATIENTS Ten children with congenital unilateral hearing loss. INTERVENTION After extensive consultation with the families and intensive counseling, the children received a cochlear implant. MAIN OUTCOME MEASURES Categories of auditory performance, speech discrimination in open set, subjective assessment by Speech, Spatial and Qualities scale questionnaire. CONCLUSION Eight of ten children use their cochlear implant consistently on a daily basis. Two children who were equipped with an implanted device at a later age tend to nonuse of the device. The evaluation of binaural hearing in small children is still difficult and methods have to be developed to allow objective assessment.