Auditory brainstem implants in neurofibromatosis Type 2: is open speech perception feasible?

OBJECT: Patients with bilateral auditory nerve destruction may perceive some auditory input with auditory brainstem implants (ABIs). Despite technological developments and trials in new stimulation sites, hearing is very variable and of limited quality. The goal of this study was to identify advantageous and critical factors that influence the quality of auditory function, especially speech perception. METHODS: The authors conducted a prospective study on ABI operations performed with the aid of multimodality neuromonitoring between 2005 and 2009 in 18 patients with neurofibromatosis Type 2. Outcome was evaluated by testing word recognition (monotrochee-polysyllabic word test at auditory-only mode [MTPa]) and open speech perception (Hochmair-Schulz-Moser [HSM] sentence test), both in pure auditory mode. The primary outcome was the HSM score at 24 months. The predictive meaning of general clinical data, tumor volume, number of active electrodes, duration of deafness, and early hearing data was examined. RESULTS: In 16 successful ABI activations the average score for MTPa was 89% (SD 13%), and for HSM it was 41% (SD 32%) at 24 months. There were 2 nonresponders, 1 after radiosurgery and the other in an anatomical variant. Direct facial nerve reconstruction during the same surgery was followed by successful nerve recovery in 2 patients, with a simultaneous very good HSM result. Patients' age, tumor extension, and tumor volume were not negative predictors. There was an inverse relationship between HSM scores and deafness duration; 50% or higher HSM scores were found only in patients with ipsilateral deafness duration up to 24 months. The higher the deafness sum of both sides, the less likely that any HSM score will be achieved (p = 0.034). In patients with total deafness duration of less than 240 months, higher numbers of active electrodes were significantly associated with better outcomes. The strongest cross-correlation was identified between early MTPa score at 3 months and 24-month HSM outcome. CONCLUSIONS: This study documents that open-set speech recognition in pure auditory mode is feasible in patients with ABIs. Large tumor volumes do not prevent good outcome. Positive preconditions are short ipsilateral and short bilateral deafness periods and high number of auditory electrodes. Early ability in pure auditory word recognition tests indicates long-term capability of open speech perception.

International consensus on Vibrant Soundbridge® implantation in children and adolescents.

OBJECTIVE: Active middle ear implants augment hearing in patients with sensorineural, conductive, and mixed hearing losses with great success. However, the application of active middle ear implants has been restricted to compromised ears in adults only. Recently, active middle ear implants have been successfully implanted in patients younger than 18 years of age with all types of hearing losses. The Vibrant Soundbridge (VSB) active middle ear implant has been implanted in more than 60 children and adolescents worldwide by the end of 2008. In October 2008, experts from the field with experience in this population met to discuss VSB implantation in patients below the age of 18. METHODS: A consensus meeting was organized including a presentation session of cases from worldwide centers and a discussion session in which implantation, precautions, and alternative means of hearing augmentation were discussed. At the end of the meeting, a consensus statement was written by the participating experts. The present consensus paper describes the outcomes and medical/surgical complications: the outcomes are favourable in terms of hearing thresholds, speech intelligibility in quiet and in noise, with a low incidence of intra- and postoperative complications. CONCLUSIONS: Taken together, the VSB offers another viable treatment for children and adolescents with compromised hearing. However, other treatment options should also be taken into consideration. The advantages and disadvantages of all possible treatment options should be weighed against each other in the light of each individual case to provide the best solution; counseling should include a.o. surgical issues and MRI compatibility.

The High Rate CIS Auditory Brainstem Implant for Restoration of Hearing in NF-2 Patients.

AIM: Hearing preservation is one of the major goals of acoustic neuroma surgery. In NF-2 patients, bilateral hearing loss is frequently caused by the disease or results from its treatment. Several implant devices for electrical stimulation of the cochlear nucleus have been developed to restore serviceable hearing in these patients. We report our experience and results using a high rate continuous interleaved sampling (CIS) auditory brainstem implant (ABI). METHODS: Between June 1997 and May 2004, 24 NF-2 patients were managed by our group. In 20 patients an ABI was implanted successfully. The cochlear nucleus was located using anatomical landmarks and E-ABR recordings after resection of the neuroma via a retrosigmoid approach in the semi-sitting position. The 12-channel stimulating electrode array was inserted and fixed in the lateral recess. There were no surgical complications related to implantation apart from pseudomeningo that were managed by lumbar drainage. RESULTS: In one patient the electrode array became dislocated and this necessitated revision surgery which was successful. One patient failed to gain benefit from the implant. Overall, 70% of electrodes were found to be serviceable for auditory stimulation, 5.3% of electrodes were primarily nonauditory, and in 7.8% side effects during stimulation were observed. Lip reading was improved by more than 100% as a result of the additional auditory input. For many patients, comprehension of open speech was restored to a useful level. Almost all patients were able to perceive environmental sounds and tinnitus was masked. CONCLUSIONS: Restoration of hearing using ABIs in NF-2 patients is a safe and promising procedure for those who would otherwise be totally deaf. The high rate CIS speech processing strategy has proven to be very useful and effective in direct cochlear nucleus stimulation.

Rare tumors of the internal auditory canal.

The study was performed to identify the incidence and histology of rare tumors with growth restricted to the internal auditory canal (IAC) that are different from vestibular schwannoma (VS). Furthermore, the question was addressed whether a preoperative diagnosis would be possible in these cases. A series of 351 patients that were operated on for IAC tumors through a transtemporal or translabyrinthine approach was investigated retrospectively. Cases with a tumor entity other than VS were analyzed for symptoms, radiological diagnosis, intraoperative findings and postoperative histolopatology to determine if a differential diagnosis to the common VS can be established prior to surgery. In 15 out of 351 cases (4.3%), uncommon processes of the IAC were determined by histology (6 lipomas, 3 hemangiomas, 2 neurofibromas, 2 menigiomas, 1 facial neuroma and 1 case of bilateral malignant lymphoma). The symptoms and the clinical manifestations were typical for patients with VS so that a preoperative differential diagnosis was not possible in the majority of cases. An analysis of the operation reports revealed that in 10 out of the 15 cases the surgeon suspected an unusual tumor of the IAC during surgery. The results of the present investigation suggest that rare lesions of the IAC can be expected in less than 5% of the cases and that preoperative diagnosis of rare IAC tumors is difficult. Intraoperative findings such as adhesion to cranial nerves and consistency of the tumor often indicate unusual processes, but histological analysis of the removed tissue is essential for the definite diagnosis.

Analysis of ceiling effects occurring with speech recognition tests in adult cochlear-implanted patients.

This article presents a simple method of analysing speech test scores which are biased through ceiling effects. Eighty postlingually deafened adults implanted with a MED-EL COMBI 40/40+ cochlear implant (CI) were administered a numbers test and a sentence test at initial device activation and at 1, 3, 6, 12 and 24 months thereafter. As a measure for speech recognition performance, the number of patients who scored at the 'ceiling level' (i.e. at least 95% correct answers) was counted at each test interval. Results showed a quick increase in this number soon after device activation as well as a continuous improvement over time (numbers test: 1 month: 51%; 6 months: 73%; 24 months: 88%; sentence test: 1 month: 33%; 6 months: 49%; 24 months: 64%). The new method allows for the detection of speech recognition progress in CI patient samples even at late test intervals, where improvement curves based on averaged scores are usually assuming a flat shape.

Induction chemotherapy with paclitaxel and cisplatin and CT-based 3D radiotherapy in patients with advanced laryngeal and hypopharyngeal carcinomas--a possibility for organ preservation.

BACKGROUND: To evaluate the effect of paclitaxel/cisplatin induction chemotherapy (ICHT) and CT-based radiotherapy (RT) on larynx preservation, tumor control, and survival in patients with larynx/hypopharynx carcinoma eligible for total laryngectomy (TL) or TL plus partial pharyngectomy (TLPP). PATIENTS AND METHODS: Fifty patients eligible for TL or TLPP were enrolled onto a prospective study and treated with ICHT (200 mg/m(2) paclitaxel, 100 mg/m(2) cisplatin; day 1, 22). In patients with complete or partial tumor response RT (69.9 Gy in 5.5 weeks at the gross tumor, 50.4 Gy in the lymphatic drainage; single dose: 1.8 Gy, concomitant boost: 1.5 Gy) was applied. Non-responders had TL/TLPP and RT with total doses adapted to the radicality of tumor resection (56-70 Gy). RESULTS: The response rate to ICHT was 88% (10% complete, 78% partial response). At a median follow-up period of 25 months the larynx preservation rate was 84%. The 2-year local-regional control rate was 91% and the 2-year overall survival rate was 72.3%. The 3-year estimate to survive with functional larynx is 60%. CONCLUSION: In a large portion of patients eligible for TL or TLPP the larynx was preserved by paclitaxel/cisplatin ICHT and 3D RT.

Assessment of auditory skills in 140 cochlear implant children using the EARS protocol.

Auditory performance of cochlear implant (CI) children was assessed with the Listening Progress Profile (LiP) and the Monosyllabic-Trochee-Polysyllabic-Word Test (MTP) following the EARS protocol. Additionally, the 'initial drop' phenomenon, a recently reported decrease of auditory performance occurring immediately after first fitting, was investigated. Patients were 140 prelingually deafened children from various clinics and centers worldwide implanted with a MEDEL COMBI 40/40+. Analysis of LiP data showed a significant increase after 1 month of CI use compared to preoperative scores (p < 0.01). No initial decrease was observed with this test. Analysis of MTP data revealed a significant improvement of word recognition after 6 months (p < 0.01), with a significant temporary decrease after initial fitting (p < 0.01). With both tests, children's auditory skills improved up to 2 years. Amount of improvement was negatively correlated with age at implantation.

Prolonged middle ear ventilation with the cartilage shield T-tube tympanoplasty.

BACKGROUND: In 1994, the favorable experience with composite cartilage shield tympanoplasty was reported to the American Otological Society. On that occasion, the technical question regarding the concomitant placement of a ventilating tube was posed. In response, the authors proposed that the tympanostomy tube be incorporated in the cartilage graft. Moreover, they proposed that this marriage, when used to reverse atelectasis and to repneumatize the middle ear, should offer the advantage of both procedures while reducing the incidence of tube extrusion and other complications of prolonged intubation. Although attractive in theory, this supposition could be validated only after prolonged follow-up, reported here. OBJECTIVE: To describe an effective means to secure prolonged middle ear ventilation in a patient population prone to atelectasis and chronic middle ear effusion and to establish the incidence of favorable and unfavorable outcomes after 6 years of observation. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Forty patients (28 adults and 12 children) who underwent tympanic membrane reconstruction with a composite cartilage shield T-tube "unit."RESULTS The overall retention rate was 62.5% over 6 years. Sixty-five percent of retained tubes were maintained for a minimum of 4 years in adult patients. Extrusion and permanent perforation rates were 0%. CONCLUSION: The cartilage shield T-tube tympanoplasty can effectively reverse atelectasis and provide prolonged middle-ear ventilation. The technique can be used safely and minimizes the risk of tympanic membrane perforation and other complications associated with prolonged middle ear intubation.

Speech reception thresholds obtained in a symmetrical four-loudspeaker arrangement from bilateral users of MED-EL cochlear implants.

OBJECTIVE: The purpose of the study was to investigate speech reception in noise in subjects who had undergone bilateral implantation with multichannel cochlear implants. METHODS: Nine adults with bilateral MED-EL implants were included in the study. The subjects were tested using both implants and the better implant only. Tests were performed in a symmetrical setup, which ideally eliminates any head shadow effect. Speech tests included sentences in quiet and at various signal-to-noise ratios. From the results, the gain in signal-to-noise ratios at the speech reception threshold was determined. RESULTS: All subjects showed a substantial gain in signal-to-noise ratios of approximately 4 dB on average. In addition, the gain in signal-to-noise ratios was essentially stable for as long as 4.4 years. CONCLUSIONS: The results indicate that bilateral cochlear implant users are able to binaurally process speech.

Revision surgery after saccotomy for Meniere's disease: does it make sense?

Saccotomy is an established surgical treatment for Meniere's disease that involves exposing and opening the endolymphatic sac and draining the endolymph. However, in patients experiencing recurrent vertigo after saccotomy, it is questionable whether revision saccotomy should be recommended as opposed to more invasive procedures, such as neurectomy of the vestibular nerve. To determine the utility of revision saccotomy, we conducted a retrospective study of 29 patients undergoing this procedure for recurrent vertigo. Patient charts were reviewed for the re-occurrence of any vertiginous symptoms and outcomes with regard to hearing results and post-operative complications. An attempt was made to correlate vertigo status post-revision with surgical findings at the time of revision. After an average follow-up of 20 months, 18 patients (62%) were free of vertigo, and four patients (14%) had a significant decrease in the frequency and intensity of vertiginous attacks. Two patients (7%) relapsed after a vertigo-free period of 18 months, and five patients (17%) experienced no clinical improvement after revision surgery. In patients with a successful sac revision, a common finding at the time of revision was new bone formation in the endolymphatic sac area (n=11), which may have caused blocking of the endolymphatic drainage. Our results demonstrate that revision saccotomy should be considered for recurrent Meniere disease before other, more invasive, surgical options.

Management of anterior epitympanic cholesteatoma: expectations after epitympanic approach and canal wall reconstruction.

BACKGROUND: The epitympanic approach to cholesteatoma provides excellent access to the anterior epitympanic space. When it is combined with reconstruction of the scutum, it is tempting to propose that the approach may offer the patient the advantage of both canal wall up and canal wall down techniques and the disadvantages of neither. In theory, then, the incidence of residual/recurrent cholesteatoma should be no greater than that for canal wall down surgery, and the need for a second look often associated with the canal wall up procedure should be less compelling. However, validation of this theory is lacking. OBJECTIVE: To test this theory, we sought to establish the incidence of recidivism in patients undergoing cholesteatoma removal via the epitympanic approach followed by canal wall reconstruction, to identify anatomic factors predisposing to persistent disease, and to identify technical features or problems associated with recurrent cholesteatoma. STUDY DESIGN: A retrospective case series. SETTING: A tertiary referral center. PATIENTS: Fifty-four adults and 11 children with extensive cholesteatoma involving but not limited to the anterior epitympanic space. INTERVENTION: All patents underwent removal of cholesteatoma via the epitympanic approach with canal wall reconstruction followed by reexploration 1 year later. RESULTS: Recurrent/residual disease was observed in 6 adults (11%) and 5 of 11 children (45%). The anterior epitympanic space harbored cholesteatoma in 100% of adults and 80% of children with recurrent disease. CONCLUSION: The epitympanic approach does not eliminate the need for reexploration in cases of extensive cholesteatoma involving the anterior epitympanic space. The anterior epitympanic space is highly likely to harbor residual disease. Features of the canal wall reconstruction can be identified that predispose to recurrence. Long-term follow-up and close surveillance are mandatory, especially in children.

An auditory brainstem implant system.

Neurofibromastosis type II (NF2) is a condition that may result in bilateral acoustic neuromas. The tumors and their removal may cause profound bilateral deafness. Because the auditory nerve is compromised, people with NF2 are unable to receive a cochlear implant to restore a sensation of hearing. Electrical stimulation of the auditory pathway can provide hearing in such people. This is possible by means of an auditory brainstem implant (ABI). This article focuses on the MED-EL high-rate multichannel ABI system. The system consists of the implanted and external components. Appropriate placement of the ABI is dependent on electrical auditory brainstem response testing performed intra-operatively. Data on a group of European patients implanted with the MED-EL ABI are presented. Results are promising and include some open-set speech ability.