Deborah Mawman

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.

Pre-, Per- and Postoperative Factors Affecting Performance of Postlinguistically Deaf Adults Using Cochlear Implants: A New Conceptual Model over Time

Objective To test the influence of multiple factors on cochlear implant (CI) speech performance in quiet and in noise for postlinguistically deaf adults, and to design a model of predicted auditory performance with a CI as a function of the significant factors. Study Design Retrospective multi-centre study. Methods Data from 2251 patients implanted since 2003 in 15 international centres were collected. Speech scores in quiet and in noise were converted into percentile ranks to remove differences between centres. The influence of 15 pre-, per- and postoperative factors, such as the duration of moderate hearing loss (mHL), the surgical approach (cochleostomy or round window approach), the angle of insertion, the percentage of active electrodes, and the brand of device were tested. The usual factors, duration of profound HL (pHL), age, etiology, duration of CI experience, that are already known to have an influence, were included in the statistical analyses. Results The significant factors were: the pure tone average threshold of the better ear, the brand of device, the percentage of active electrodes, the use of hearing aids (HAs) during the period of pHL, and the duration of mHL. Conclusions A new model was designed showing a decrease of performance that started during the period of mHL, and became faster during the period of pHL. The use of bilateral HAs slowed down the related central reorganization that is the likely cause of the decreased performance.

Evaluation of bilaterally implanted adult subjects with the nucleus 24 cochlear implant system.

Objective: To evaluate the speech perception benefits of bilateral implantation for subjects who already have one implant. Study Design: Repeated measures. Patients: Thirty adult cochlear implant users who received their second implant from 1 to 7 years with a mean of 3 years after their first device. Ages ranged from 29 to 82 years with a mean of 57 years. Setting: Tertiary referral centers across the United Kingdom. Main Outcome Measures: Monosyllabic consonant-nucleus-consonant words and City University of New York sentences in quiet with coincident speech and noise and with the noise spatially separated from the speech by ±90°. Results: At 9 months, results showed the second ear in noise was 13.9 ± 5.9% worse than the first ear (p < 0.001); a significant binaural advantage of 12.6 ± 5.4% (p < 0.001) over the first ear alone for speech and noise from the front; a 21 ± 6% (p < 0.001) binaural advantage over the first ear alone when noise was ipsilateral to the first ear; no binaural advantage when noise was contralateral to the first ear. Conclusions: There is a significant bilateral advantage of adding a second ear for this group. We were unable to predict when the second ear would be the better performing ear, and by implanting both ears, we guarantee implanting the better ear. Sequential implantation with long delays between ears has resulted in poor second ear performance for some subjects and has limited the degree of bilateral benefit that can be obtained by these users. The dual microphone does not provide equivalent benefit to bilateral implants.

Cochlear implant outcomes and quality of life in the elderly: Manchester experience over 13 years.

Objectives:  To objectively evaluate the clinical and functional outcomes of cochlear implantation in an elderly population.

Predictors of audiological outcome following cochlear implantation in adults.

Abstract The objective of this study was to examine variables that may predict open set speech discrimination following cochlear implantation. It consisted of a retrospective case review conducted in a tertiary referral centre with a cochlear implant programme. The patients were 117 postlingually deafened adult cochlear implant recipients. The main outcome measures were Bench, Kowal, Bamford (BKB) sentence scores recorded nine months following implant activation. The variables studied were age at the time of surgery, sex, duration of hearing loss, aetiology of hearing loss, residual hearing, implant type, speech processor strategy, number of active electrodes inserted. Variables found to have a significant effect on BKB following univariate analysis were entered into a multivariate analysis to determine independent predictors. Multivariate ordinal regression analysis gave an odds ration of 1.09 for each additional year of deafness prior to implantation (confidence interval 1.06–1.13; p<0.001). Duration of deafness prior to implantation is an independent predictor of implant outcome. It accounted for 9% of the variability. Other factors must influence implant performance. Copyright

Cochlear implantation in the presence of chronic suppurative otitis media

Nine patients are presented who underwent cochlear implantation in the presence of chronic suppurative otitis media. Four had a simple tympanic membrane perforation, four had a pre-existing mastoid cavity and one had cholesteatoma in the ear chosen for implantation. Patients with a simple perforation had a staged procedure with myringoplasty followed by cochlear implantation after an interval of three months. Patients with cholesteatoma or with an unstable mastoid cavity were also staged. A mastoidectomy or revision mastoidectomy was performed with obliteration of the middle ear and mastoid using a superiorly pedicled temporalis muscle flap and blind sac closure of the external meatal skin. After a further six months a second stage procedure was performed to confirm that the middle-ear cleft was healthy and to insert the implant. Patients presenting with a stable mastoid cavity underwent obliteration of the cavity and implantation of the electrode as a one-staged procedure. To date there have been no serious problems such as graft breakdown, recurrence of disease or implant extrusion, and all patients are performing well.

Hearing preservation via a cochleostomy approach and deep insertion of a standard length cochlear implant electrode.

Objective The suggestion that the depth of insertion of the electrode into the cochlea is critical to hearing preservation has led to the development of a generation of short electrodes designed to minimize intracochlear trauma and avoid contact with the apical region of the cochlea. This study aims to describe our experience of hearing preservation surgery using a deeply inserted standard length electrode array covering the region of residual hearing. Study Design A retrospective case note review was performed identifying cases of attempted hearing preservation using standard length electrodes. Setting Study based at Manchester Royal Infirmary, a tertiary referral center. Patients Fourteen cochlear implants in 13 patients were identified for further analysis from the Manchester Cochlear Implant Programme database. Intervention(s) Each patient received the same design of implant using a “soft” surgical technique. Main Outcome Measure Preoperative and postoperative air conduction thresholds were compared to assess the degree of hearing preservation. Results Successful hearing preservation was demonstrated in 12 of 14 cases, and the postoperative residual hearing thresholds in 3 adolescents receiving a standard length electrode array were found to have improved. Preservation of speech recognition was not measured in this study, rather hearing was tested by pure tone audiogram. Follow-up at the time of this study ranged from 1 week to 23 months. Conclusion This study demonstrates that deep insertion of the electrode into the cochlea does not preclude successful hearing preservation. It also highlights that residual hearing can be consistently preserved using a “cochleostomy” approach.

A retrospective Multicenter Study comparing Speech Perception outcomes for Bilateral Implantation and Bimodal rehabilitation

Objectives: To compare speech perception outcomes between bilateral implantation (cochlear implants [CIs]) and bimodal rehabilitation (one CI on one side plus one hearing aid [HA] on the other side) and to explore the clinical factors that may cause asymmetric performances in speech intelligibility between the two ears in case of bilateral implantation. Design: Retrospective data from 2247 patients implanted since 2003 in 15 international centers were collected. Intelligibility scores, measured in quiet and in noise, were converted into percentile ranks to remove differences between centers. The influence of the listening mode among three independent groups, one CI alone (n = 1572), bimodal listening (CI/HA, n = 589), and bilateral CIs (CI/CI, n = 86), was compared in an analysis taking into account the influence of other factors such as duration of profound hearing loss, age, etiology, and duration of CI experience. No within-subject comparison (i.e., monitoring outcome modifications in CI/HA subjects becoming CI/CI) was possible from this dataset. Further analyses were conducted on the CI/CI subgroup to investigate a number of factors, such as implantation side, duration of hearing loss, amount of residual hearing, and use of HAs that may explain asymmetric performances of this subgroup. Results: Intelligibility ranked scores in quiet and in noise were significantly greater with both CI/CI and CI/HA than with a CI-alone group, and improvement with CI/CI (+11% and +16% in quiet and in noise, respectively) was significantly better than with CI/HA (+6% and +9% in quiet and in noise, respectively). From the CI/HA group, only subjects with ranked preoperative aided speech scores >60% performed as well as CI/CI participants. Furthermore, CI/CI subjects displayed significantly lower preoperative aided speech scores on average compared with that displayed by CI/HA subjects. Routine clinical data available from the present database did not explain the asymmetrical results of bilateral implantation. Conclusions: This retrospective study, based on basic speech audiometry (no lateralization cues), indicates that, on average, a second CI is likely to provide slightly better postoperative speech outcome than an additional HA for people with very low preoperative performance. These results may be taken into consideration to refine surgical indications for CIs.

Ipsilateral cochlear implantation after cochlear nerve preserving vestibular schwannoma surgery in patients with neurofibromatosis type 2.

Objective To investigate the outcomes from ipsilateral simultaneous or sequential cochlear implantation in patients with neurofibromatosis type 2 (NF2) after vestibular schwannoma removal with cochlear nerve preservation. Study Design Retrospective case series. Setting Single tertiary referral NF2 center. Patients Six patients with NF2. Intervention Removal of vestibular schwannoma (VS) with preservation of the cochlear nerve and cochlear implantation. Four patients had their surgery via a translabyrinthine approach. Two patients had a retrosigmoid approach. A cochlear implant was inserted at the same time as tumor removal in 4 cases and sequentially in 2 cases. Main Outcome Measures Surgical and audiometric outcomes using Bamford-Kowal-Bench (BKB) and City of New York University (CUNY) sentence scores. Results The average age at implantation was 24 years (range, 15–36 yr). Follow-up ranged from 5 to 93 months, with an average of 38 months. All patients had useful hearing in the contralateral ear before surgery. One patient gained no benefit from cochlear implantation and proceeded to have an auditory brainstem implant. Of those that had functional cochlear nerves, the average BKB score in quiet was 64%, BKB score in noise was 42%, and CUNY score with lipreading was 97%. Results varied within the group, but all patients gained significant benefit and continue to use their CI at least intermittantly. Conclusion The present series demonstrates that in selected cases, cochlear implantation can be successful after a translabyrinthine approach for VS removal and for restoring hearing after failed retrosigmoid hearing preservation surgery. All patients found the cochlear implant offered useful hearing even in the presence of contralateral hearing.

Vestibular schwannoma in the only hearing ear: cochlear implant or auditory brainstem implant?

Objective: To explore the dilemma faced by neurotologists confronted with the patient who develops a vestibular schwannoma in the only hearing ear, the other having been deaf from birth, and to consider the choice between auditory rehabilitation using a cochlear implant (CI) on the congenitally deaf side and an auditory brainstem implant (ABI) on the tumor side. Study Design: A record review of two patients born deaf in one ear and who developed a vestibular schwannoma in the contra lateral ear, who then received a CI in the congenitally deaf ear. Setting: Tertiary referral center with special experience in vestibular schwannoma surgery, neurofibromatosis type 2 management, and cochlear implantation. Results: Neither patient was a good CI user. At 1 year postimplant, they both scored 0% on abbreviated words and 0% and 7%, respectively, on Bench Kowal Bamford sentences. They scored 54% and 57%, respectively, on City University of New York sentences with lip-reading, and both had fair access to environmental sound scoring at 45% each. Conclusions: The results from cochlear implantation in the congenitally deaf ear in these patients were poor and suggest that stimulus deprivation in the early stages of the maturation of the auditory pathways is important even for a unilateral hearing loss. Unfortunately, the factors that predict a good ABI result are not known. In these circumstances, the authors advocate the insertion of an ABI at the time of tumor removal, retaining the option of CI in the congenitally deaf ear in the event of a poor outcome with the ABI.