The effect of angulation of the vibrating floating mass transducer on stapes velocity.

HYPOTHESIS: Changes to the angular position of the vibrating floating mass transducer (FMT) coupled to the long process of the incus will not affect stapes velocity. OBJECTIVE: The MED-EL Vibrant Soundbridge is an active middle ear implantable device, which constitutes an effective alternative to acoustic hearing aids for the rehabilitation of patients with sensorineural and mixed hearing loss. Because of varied anatomy, it is not always possible to position the FMT in line with the vibrating axis of the stapes. Changes in stapes velocity after angulation of the FMT are measured using laser Doppler vibrometry (LDV). METHODS: The study was performed on 7 human cadaveric temporal bones. The FMT was attached to the incus and angled at the recommended 0 degree or at 45 degrees relative to the vibrating axis of the stapes, and the stapes velocity measured using LDV. RESULTS: In comparison to the 0-degree position, angulating the FMT to 45 degrees reduced cochlea input as measured by stapes velocity, although there was no statistical significance to this difference. Placing the FMT at 45 degrees did not compromise the peak output of the device but resulted in a phase lag which was more marked compared with the 0-degree position. CONCLUSION: If it is not anatomically possible to position the FMT in line with the vibrating axis of the stapes, then placement at up to 45 degrees does not significantly alter the performance of the implant particularly in the midfrequencies that are crucial to the understanding of speech.

The atretic plate--a conduit for drill vibration to the inner ear?

CONCLUSION: In the presence of simulated congenital aural atresia with fixation of the ossicular chain to the surrounding bone, access to the chain for placement of a middle ear prosthesis using the rotating burr is not associated with significant stapes movement that would cause vibrational trauma to the cochlea. OBJECTIVES: To determine the energy transmitted to the cochlea while drilling the mastoid in an ear with simulated congenital aural atresia and fixation of the ossicular chain to the surrounding bone. METHODS: Eight human cadaveric temporal bones were used. Cement was placed in the external auditory canal and on the incudomalleolar joint and surrounding epitympanum, to simulate congenital aural atresia and ossicular fixation, respectively. Stapes vibration was measured with the Laser Doppler Vibrometer using acoustic then drill stimulation by touching the wall of the epitympanum with a running burr. RESULTS: Using acoustic stimulation, all bones showed frequency-specific reduction of stapes motion of up to 17 dB with fixation of the ossicular chain to the surrounding bone. There was no measurable stapes motion when the external auditory canal was filled with cement. On drill stimulation, there was no difference in stapes velocity between the normal bone and the bone with simulated congenital aural atresia.

Systematic review of cochlear implantation in children with developmental disability.

OBJECTIVE: To perform a systematic review comparing the xoutcome of cochlear implantation in children with developmental disability with children without developmental disability. DATA SOURCES: MEDLINE, EMBASE, and Cochrane databases were searched from 1950 or the start date of each database. The search was performed on 1st November 2012, and included articles published ahead of print with no language restrictions. STUDY SELECTION: The initial search presented 441 articles of which 13 met the inclusion criteria. The articles studied children with cochlear implants and developmental disability where expressive and/or receptive language outcomes were compared with children with cochlear implants and normal development. DATA EXTRACTION: Study quality assessment included whether ethical approval was gained, prospective design, eligibility criteria specified, appropriate controls used, adequate follow-up achieved, and defined outcome measures. Cochlear implant outcome analysis included expressive/receptive speech and language development in addition to quality of life and behavior. DATA SYNTHESIS: Because of heterogeneity in postoperative follow-up periods and outcome measures reported, it was not possible to pool the data and perform meta-analysis. Comparisons were made by structured review. CONCLUSION: Seven studies demonstrated a worse outcome for children with developmental disability. Six articles showed no difference in the outcome between the 2 groups. Children with developmental disability may not benefit from cochlear implantation based on traditional assessment tools but appear to improve their environmental awareness and quality of life. More work is needed to define the term benefit when used in this context for this vulnerable group. Autistic children consistently had a negative outcome.

Cochlear implantation in patients with vestibular schwannoma: a single United Kingdom center experience.

OBJECTIVES/HYPOTHESIS: To evaluate the outcome of cochlear implantation (CI) in patients with vestibular schwannoma (VS). STUDY DESIGN: A retrospective case series from a tertiary auditory implant center. METHODS: A retrospective case note review was carried out to evaluate patients with bilateral profound hearing loss and VS who underwent unilateral CI within the Auditory Implant Centre at St. Thomas' Hospital, London, between 2000 and 2012. This included both bilateral VS with neurofibromatosis type 2 (NF2) and unilateral sporadic VS. Outcome measures included speech perception with Bamford-Kowal-Bench and City University of New York sentences, sound-field thresholds with warble tones, and the subjective benefits reported by patients. RESULTS: The study included five patients with NF2 and bilateral VS and two patients with sporadic unilateral VS. The standard preoperative audiologic assessment for CI often could not be carried out in NF2 patients. Preoperative testing was more complete in the two patients with sporadic VS. The audiologic outcome was variable. Open-set speech perception was achieved in three out of five NF2 patients, and another reported significant improvement in environmental sound perception and ease of communication. The outcome was overall better in patients with sporadic VS, both of whom were able to use the telephone in their implanted ear. CONCLUSIONS: Good speech perception can be achieved in some cases, and CI should be considered as an option for auditory rehabilitation in patients with VS.

Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants: an update with 2251 patients.

OBJECTIVE: To update a 15-year-old study of 800 postlinguistically deaf adult patients showing how duration of severe to profound hearing loss, age at cochlear implantation (CI), age at onset of severe to profound hearing loss, etiology and CI experience affected CI outcome. STUDY DESIGN: Retrospective multicenter study. METHODS: Data from 2251 adult patients implanted since 2003 in 15 international centers were collected and speech scores in quiet were converted to percentile ranks to remove differences between centers. RESULTS: The negative effect of long duration of severe to profound hearing loss was less important in the new data than in 1996; the effects of age at CI and age at onset of severe to profound hearing loss were delayed until older ages; etiology had a smaller effect, and the effect of CI experience was greater with a steeper learning curve. Patients with longer durations of severe to profound hearing loss were less likely to improve with CI experience than patients with shorter duration of severe to profound hearing loss. CONCLUSIONS: The factors that were relevant in 1996 were still relevant in 2011, although their relative importance had changed. Relaxed patient selection criteria, improved clinical management of hearing loss, modifications of surgical practice, and improved devices may explain the differences.

STARR: a speech test for evaluation of the effectiveness of auditory prostheses under realistic conditions.

OBJECTIVES: The objective was to develop and evaluate a new sentence test, the Sentence Test with Adaptive Randomized Roving levels, intended to emulate everyday listening experience, using both normal-hearing (NH) and cochlear implant (CI) groups, examining practicality, learning, test-retest variability, and interlist variability. DESIGN: In experiment 1, each of 25 NH adults was tested using five lists, each comprising 30 sentences. One male and one female speaker each spoke 15 sentences. Ten sentences were presented at each of three presentation levels: 50, 65, and 80 dB SPL. The relative level of a speech-shaped noise was varied adaptively to estimate the speech reception threshold (SRT). Counterbalance for list order was achieved by staggering the allocation of lists to participants. To allow assessment of learning effects, no practice was given. The variability of mean SRTs across lists was small, but correction factors were derived for each list so that, after correction, all lists gave the same mean SRT. Test-retest variability was estimated by examining the corrected SRTs for each subject's five lists. In experiment 2, 25 CI users each received one test list after a small amount of practice. Experiment 3 examined the effect of speech rate using time-compressed speech, for age-matched NH and CI users. RESULTS: The mean SRT for the NH participants was approximately -6 dB and was similar for the male and female speakers. There was a small but significant improvement in SRTs between the first and later lists administered, but no further improvement for subsequent lists. On the basis of the variability of the corrected SRTs within each participant, a 2.2 dB difference in SRT is meaningful for comparisons using one test list per condition, for a single participant. The percentage of key words correct varied with presentation level over a 13% range, being best at 65 dB SPL. Only 40% of the CI group achieved an SRT lower than 20 dB for both speakers. There was large individual variability in the SRTs, and SRTs were higher for the female than for the male speaker. For the CI participants, the percentage of key words correct varied markedly with level, from 19% at the lowest level to 57% at the medium level. Time compression had a small effect for NH participants but a very large effect for CI participants. CONCLUSIONS: The Sentence Test with Adaptive Randomized Roving levels seems practical to administer and is reasonably sensitive. For NH participants, a 2.2 dB difference in SRT is meaningful for a single list per condition and a single participant. Although learning effects were small for NH participants, it seems prudent to provide some practice sentences when testing hearing-impaired or CI participants. The very large effect of time compression for the CI group has implications for live voice testing of children, because speech rate is only poorly controlled in such testing.

Outcome of bone-anchored hearing aids for single-sided deafness: a prospective study.

CONCLUSION: The bone-anchored hearing aid (BAHA) system can offer significant benefits to patients with single-sided deafness (SSD), primarily by lifting the head shadow effect. OBJECTIVE: To evaluate the efficacy of BAHA for SSD by comparing pre- and postoperative speech, spatial and qualities of hearing scale (SSQ) scores. METHODS: This was a prospective study conducted within a tertiary auditory implant department. The inclusion criteria were unilateral profound hearing loss with normal or mild high frequency hearing loss in the hearing ear (pure tone average better than or equal to 25 dBHL measured at 0.5, 1, 2 and 3 kHz) and subjective benefits reported by patients following a home trial with a BAHA Softband. Patients who met the above criteria and opted for surgery were asked to complete the SSQ questionnaire. The postoperative SSQ response was collected after at least 6 months of consistent BAHA usage. RESULTS: This study included 25 adult patients (mean age at implantation 57.5 years). There was a statistically significant improvement in the average SSQ score in all three sections of the questionnaire with the use of the BAHA. Our patients experienced most marked benefits in speech hearing in challenging listening situations. All patients remain consistent users and there has been no explantation to date.

Assessment of the subjective benefit of electric acoustic stimulation with the abbreviated profile of hearing aid benefit.

CONCLUSION: This study demonstrates that electric-acoustic stimulation (EAS) significantly decreases the subjective impairment in speech perception. OBJECTIVES: To assess the subjective benefit of EAS over the first 12 months after EAS fitting using the Abbreviated Profile of Hearing Aid Benefit (APHAB). METHOD: Twenty-three EAS users, implanted with either the PULSAR(CI)(100) FLEX(EAS) provided with the DUET EAS processor or the COMBI40+ Medium provided with the TEMPO+ speech processor, were included. Electric stimulation was activated about 1 month postoperatively; ipsilateral acoustic stimulation was added 2 months thereafter. EAS benefit was measured preoperatively with only a hearing aid and postoperatively at EAS fitting and then 3, 6 and 12 months after EAS fitting using the APHAB. RESULTS: Subjects reported significant improvements in the global score with a mean decrease in impairment from 74% preoperatively to 45% after 3 months of EAS use. Furthermore, clinical relevance was demonstrated in multiple subscales between preoperative and first fitting reflecting a true benefit of EAS with a probability of 95%.

A systematic review of diffusion-weighted magnetic resonance imaging in the assessment of postoperative cholesteatoma.

OBJECTIVE: A systematic review to determine whether the diffusion-weighted (DW) magnetic resonance imaging scan can reliably detect residual or recurrent cholesteatoma after mastoid surgery. DESIGN: A systematic review. DATA SOURCES: Databases including EMBASE, MEDLINE, CINAHL, Web of Science, and Cochrane Review were searched for studies published without language restriction from the start of the databases. Additional studies were identified from cited references. SELECTION CRITERIA: Initial search identified 402 publications, of which 16 studies met the inclusion criteria for the systematic review. The DW imaging (DWI) scan was used to detect residual or recurrent cholesteatoma and subsequent second-look surgery was performed to correlate the findings. REVIEW METHODS: Studies were assessed for their selection of patients for radiologic investigations, imaging parameters, and subsequent surgery. Outcome measures included sensitivity, specificity, positive and negative predictive values of the DWI, and the incidence and size of residual or recurrent cholesteatoma. RESULTS: Two different modalities of DWI sequences have been described. Eight studies with 225 patients analyzed echo-planar imaging (EPI) and 8 studies with 207 patients described the "non-EPI" scanning techniques. Non-EPI parameters are more reliable in identifying residual or recurrent cholesteatoma with sensitivity, specificity, and positive and negative predictive values of 91%, 96%, 97%, and 85%, respectively. CONCLUSION: The available evidence suggests that non-EPI such as half-Fourier acquisition single-shot turbo spin echo sequences are more reliable in identifying residual or recurrent cholesteatoma. This is a promising radiologic investigation; however, we think further studies are required with more patients and long-term results to establish its place as an alternative to a second-stage surgery after canal wall up surgery.

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.

Systematic review of middle ear implants: do they improve hearing as much as conventional hearing AIDS?

OBJECTIVE: A systematic review to determine whether middle ear implants (MEIs) improve hearing as much as hearing aids. DATA SOURCES: Databases included MEDLINE, EMBASE, DARE, and Cochrane searched with no language restrictions from 1950 or the start date of each database. STUDY SELECTION: Initial search found 644 articles, of which 17 met the inclusion criteria of MEI in adults with a sensorineural hearing loss, where hearing outcomes and patient-reported outcome measures (PROMs) compared MEI with conventional hearing aids (CHAs). DATA EXTRACTION: Study quality assessment included whether ethical approval was gained, the study was prospective, eligibility criteria specified, a power calculation made and appropriate controls, outcome measures, and analysis performed. Middle ear implant outcome analysis included residual hearing, complications, and comparison to CHA in terms of functional gain, speech perception in quiet and in noise, and validated PROM questionnaires. DATA SYNTHESIS: Because of heterogeneity of outcome measures, comparisons were made by structured review. CONCLUSION: The quality of studies was moderate to poor with short follow-up. The evidence supports the use of MEI because, overall, they do not decrease residual hearing, result in a functional gain in hearing comparable to CHA, and may improve perception of speech in noise and sound quality. We recommend the publication of long-term results comparing MEI with CHA, reporting a minimum of functional gain, speech perception in quiet and in noise, complications, and a validated PROM to guide the engineering of the new generation of MEI in the future.

An illuminated retractor for minimal access surgery in cochlear implantation: How we do it.

CONCLUSION: Use of a Langenback retractor with an Ultrathin™ Lightmat(®) light source can adequately illuminate the entire surgical field inside the subperiosteal pocket and facilitate ease of surgery and safer drilling. OBJECTIVES: Minimal access surgery for cochlear implantation has become widely accepted as it reduces surgical time and morbidity. Adequate illumination is required when drilling a bony recess for the receiver-stimulator package within a subperiosteal pocket. METHODS: An Ultrathin™ Lightmat(®) adhesive strip was attached to the Langenback retractor used for retraction of the wound. RESULTS: No adverse effects or surgical complications associated with the use of the Lightmat(®) occurred. It was particularly helpful in the bony dissection to the dura often needed in paediatric cochlear implantation.

Electric acoustic stimulation of the auditory system: results of a multi-centre investigation.

CONCLUSION: A high rate of hearing preservation during cochlear implantation for electric acoustic stimulation (EAS) is possible, even when surgery is conducted by a number of different surgeons. OBJECTIVES: This study aimed to determine the degree of hearing preservation using surgery for EAS in a European multi-centre clinical investigation. It also aimed to demonstrate the effect of EAS in individuals with residual low frequency hearing, both on speech perception and on subjective quality of life measures. PATIENTS AND METHODS: Eighteen patients with profound high frequency hearing loss were recruited in five participating European centres. Subjects were assessed based on an audiologic test battery, as well as on a subjective hearing aid benefit questionnaire. Each subject underwent attempted hearing preservation cochlear implantation using the MED-EL C40 + device with a Medium electrode. Residual ipsilateral hearing and speech discrimination abilities were assessed at defined intervals up to 12 months after the combined electric-acoustic mode was introduced. RESULTS: Results showed that some degree of hearing preservation was possible in 15718 patients. All subjects showed statistically significant benefit on all three speech perception tests over time. These significant benefits were also reflected in the subjective benefit outcomes.

Equivalent noise level generated by drilling onto the ossicular chain as measured by laser Doppler vibrometry: a temporal bone study.

BACKGROUND: Inadvertent drilling on the ossicular chain is one of the causes of sensorineural hearing loss (HL) that may follow tympanomastoid surgery. A high-frequency HL is most frequently observed. It is speculated that the HL is a result of vibration of the ossicular chain resembling acoustic noise trauma. It is generally considered that using a large cutting burr is more likely to cause damage than a small diamond burr. AIM: The aim was to investigate the equivalent noise level and its frequency characteristics generated by drilling onto the short process of the incus in fresh human temporal bones. METHODS AND MATERIALS: Five fresh cadaveric temporal bones were used. Stapes displacement was measured using laser Doppler vibrometry during short drilling episodes. Diamond and cutting burrs of different diameters were used. The effect of the drilling on stapes footplate displacement was compared with that generated by an acoustic signal. The equivalent noise level (dB sound pressure level equivalent [SPL eq]) was thus calculated. RESULTS: The equivalent noise levels generated ranged from 93 to 125 dB SPL eq. For a 1-mm cutting burr, the highest equivalent noise level was 108 dB SPL eq, whereas a 2.3-mm cutting burr produced a maximal level of 125 dB SPL eq. Diamond burrs generated less noise than their cutting counterparts, with a 2.3-mm diamond burr producing a highest equivalent noise level of 102 dB SPL eq. The energy of the noise increased at the higher end of the frequency spectrum, with a 2.3-mm cutting burr producing a noise level of 105 dB SPL eq at 1 kHz and 125 dB SPL eq at 8 kHz. In contrast, the same sized diamond burr produced 96 dB SPL eq at 1 kHz and 99 dB at 8 kHz. CONCLUSION: This study suggests that drilling on the ossicular chain can produce vibratory force that is analogous with noise levels known to produce acoustic trauma. For the same type of burr, the larger the diameter, the greater the vibratory force, and for the same size of burr, the cutting burr creates more vibratory force than the diamond burr. The cutting burr produces greater high-frequency than lower-frequency vibratory energy.