David B. Shipp

Factors Affecting Auditory Performance of Postlinguistically Deaf Adults Using Cochlear Implants

A model of auditory performance and a model of ganglion cell survival in postlinguistically deafened adult cochlear implant users are suggested to describe the effects of aetiology, duration of deafness, age at implantation, age at onset of deafness, and duration of implant use. The models were compared with published data and a composite data set including 808 implant users. Qualitative agreement with the model of auditory performance was found. Duration of deafness had a strong negative effect on performance. Age at implantation had a slight negative effect on performance, increasing after age 60 years. Age at onset of deafness had little effect on performance up to age 60. Duration of implant use had a positive effect on performance. Aetiology had a relatively weak effect on performance.

Intratympanic Gentamicin for the Treatment of Unilateral Meniere's Disease†

Objective To determine the efficacy of intratympanic gentamicin instillation as treatment of incapacitating unilateral Menieres disease, using a predetermined regimen with a fixed dose.

Early-deafened adult cochlear implant users: assessment of outcomes.

OBJECTIVE To determine whether adults deafened in the prelingual and perilingual stages of speech development realize objective and subjective benefits from cochlear implantation. METHOD Retrospective analysis of the open-set speech recognition and subjective data such as use and quality of life. RESULTS Between 1989 and 1999, 198 deafened adults underwent cochlear implantation at Sunnybrook and Womens College Health Sciences Centre. Of these, 44 patients were deafened pre- or perilingually. These subjects were implanted with a Nucleus 22, Nucleus 24 (Cochlear Corporation, Denver, Colorado, USA), or Clarion (Advanced Bionics Corporation, Sylmar, California, USA) device. The average age at implantation was 34 years (range 14-62 years). Significant differences in speech perception, as measured by a composite score of open-set word, phoneme, and sentence recognition, were found among groups who differed by type of education and communication training received in childhood. CONCLUSION By and large, open-set speech recognition in prelingually and perilingually deafened adults is inferior to that achieved in postlingually deafened adults and varies according to the type of communication training they received. However, cochlear implants have significantly improved the overall communication skills and quality of life in all subgroups of patients.

Benefits of cochlear implantation in early-deafened adults: the Toronto experience.

OBJECTIVE To present the results of a survey administered to a group of early-deafened cochlear implants adults and to report the level of perceived benefit. DESIGN Prospective. SETTING Large tertiary referral centre. METHOD A 47-item questionnaire designed to evaluate cochlear implant use and benefit was sent to 42 early-deafened adult cochlear implant users. The questionnaire can be divided into seven subcategories: time of use, associated symptoms, communication, employment status and function, socialization, perceived benefit, and the impact on quality of life. Responses from 30 patients were received. RESULTS The majority of our patients use their cochlear implant all of their waking hours. The majority of patients continue to depend on lip-reading and hearing as their main mode of communication, although they reported improved lip-reading skills with their cochlear implant. Twenty-three patients (76.7%) were employed. Eleven patients had a change in employment subsequent to cochlear implantation, nine (81.8%) of whom attributed this to their cochlear implant. Our patients als reported greater independence, a greater sense of safety in their environment, and an improved social life. Twenty-nine patients (96.7%) said that they were satisfied with their implant, 28 (93.3%) said that they would go through the same process again, and 27 (90%) said that they would recommend it to a friend in a similar situation. Twenty-nine patients (96.7%) stated that the cochlear implant has had a positive effect on their quality of life. Family and peer support, prior auditory-verbal therapy, and a positive attitude were the most commonly cited factors in successful cochlear implant use. CONCLUSIONS Early-deafened adult cochlear implant users perceive significant benefit from cochlear implantation. Importantly, family and peer support, prior auditory-verbal therapy, and a positive attitude are considered important factors in maximizing this benefit.

Does choosing the "worse" ear for cochlear implantation affect outcome?

Objective To determine whether choosing the “better” ear or the “worse” ear for cochlear implantation impacts performance outcome. Design Retrospective cohort study. Setting University teaching hospital–cochlear implant program. Methods Two groups of cochlear implantees were selected and matched based on clinical parameters, including duration of deafness/age at implantation, implant types, and processing strategies. Nineteen patients received an implant in his or her “better” ear of the two that had been amplified. An equal number of patients received an implant in the “worse” ear— an ear that was not amplified or was chosen to avoid causing oscillopsia; or if the patient was not willing to relinquish his or her hearing aid in the “better” ear based on subjective or objective criteria. Standard speech perception testing was performed. Results The average open-set speech perception responses at 1 year after implantation were as follows: word recognition score 40.4% and sentence recognition score 81% in the aided subjects (better ears); word recognition score 41.5% and sentence recognition score 84.5% in the unaided group (worse ears). Conclusion No differences were found between the two groups of implantees. Choosing the “worse” ear for implantation did not appear to have a negative impact on performance outcome in this match-paired study.

Speech coding strategies and revised cochlear implant candidacy: An analysis of post-implant performance

Objective Technological advances in cochlear implant systems on which a sequence of speech coding strategies have been implemented seem to have resulted in improved speech perception. However, changing selection criteria for implantation have coincided with evolving technology and may confound post-implantation speech perception performance. This study compares speech coding strategy with speech perception performance in severe and profound postlingually deafened adults using one of three successive generations of Nucleus Cochlear Implant speech processors (i.e., Mini Speech Processor, Spectra 22, and SPrint) implementing three speech coding strategies (i.e., MPEAK, SPEAK, and Advanced Combination Encoders; Cochlear Corporation, Englewood, CO, U.S.A.). Study Design Four cohorts of patients were retrospectively reviewed. Setting Multicenter, tertiary referral cochlear implant programs in Ontario, Canada. Methods Four cohorts of patients (n = 139) were identified based on preimplant audiological measures, duration of deafness, device type, and speech coding strategy. Word and sentence recognition scores at 12 months after implantation were compared using MPEAK with SPEAK22 implemented on the Nucleus 22 speech processors (Mini Speech Processor and Spectra22, respectively) and SPEAK24 as well as Advanced Combination Encoders implemented on the Nucleus 24 SPrint processor. Results Open-set speech recognition batteries revealed significant improvements in word and sentence scores as advancing technology implemented new speech coding strategies. Subgroup analysis of profoundly deafened patients supported this. Analysis of covariance confirmed that the measured differences could not be accounted for by changing selection criteria for implantation. Conclusion Improvements in performance can be attributed to evolving speech coding strategies and speech processors rather than to differences in preimplant candidacy.

Unilateral multi-channel cochlear implantation results in significant improvement in quality of life.

Objectives To investigate the effects of unilateral multi-channel cochlear implant surgery on health-related quality of life and to determine if there is an age-related impact of cochlear implantation on these effects. Design Prospective study. Setting Tertiary health-care center. Methods The Short Form-36 survey (SF-36) was administered to determine the health-related quality of life of 283 age-stratified patients before and after cochlear implant surgery. Main Outomes Precochlear to postcochlear implantation changes in health-related quality of life as determined by the SF-36 questionnaire. Results There were significant increases in precochlear and postcochlear implantation scores for 5 of the 8 SF-36 survey domains: vitality, physical role functioning, mental health, emotional role functioning, and social functioning. Significant differences were found between age groups in the domains of social functioning, emotion role functioning, and mental health. Conclusion Cochlear implant surgery significantly improves health-related quality of life as categorically stratified by the SF-36 questionnaire. These improvements were most evident in the mental health, emotional and social functioning, and physical functioning at work questions of the survey. Cochlear implant recipients younger than 65 years perceive a greater improvement in their level of energy, mental health, and social function compared with those older than 65 years. Level of Evidence N/A.

Results with cochlear implantation in adults with speech recognition scores exceeding current criteria.

Objectives The primary purpose of this study was to evaluate a group of postlingually deafened adults, whose aided speech recognition exceeded commonly accepted candidacy criteria for implantation. The study aimed to define performance and qualitative outcomes of cochlear implants in these individuals compared with their optimally fitted hearing aid(s). Study Design Retrospective case series. Setting Tertiary referral center. Patients All postlingually deafened subjects (N = 27), who were unsuccessful hearing aid users implanted between 2000 and 2010 with a preimplantation Hearing in Noise Test (HINT) score of 60% or more were included. Intervention We compared patients’ preoperative performance (HINT score) with hearing aids to postoperative performance with the cochlear implant after 12 months of device use. In addition, the Hearing Handicap Inventory questionnaire was used to quantify the hearing-related handicap change perceived after the implantation. Results The study group demonstrated significant postoperative improvement on all outcome measures; most notably, the mean HINT score improved from 68.4% (standard deviation, 8.3) to 91.9% (standard deviation, 9.7). Additionally, there was a significant improvement in hearing-related handicap perceived by all patients. Conclusion The envelope of implantation candidacy criteria continues to expand as shown by this study’s cohort. Patient satisfaction and speech recognition results are very encouraging in support of treating those who currently perform at a level above the conventional candidacy threshold but struggle with optimally fitted hearing aids.

A matched-pair comparison of two cochlear implant systems.

OBJECTIVES To compare the overall performance of two implant systems based on audiologic outcome, tinnitus handicap, and quality of life using objective and subjective measures. DESIGN Retrospective cohort study. SETTING Sunnybrook & Womens College Health Science Centre. METHODS Two matched groups, with 24 Nucleus 22 SPEAK (Advanced Bionics, Symlar, CA) and 24 Clarion CIS (Cochlear Corporation, Sydney, Australia), were selected. Patients were administered survey forms to evaluate subjective tinnitus and dizziness symptomatology, as well as a 27-item tinnitus handicap questionnaire. Both groups were administered survey forms to assess the frequency of implant use, the subjective benefit derived, and the perceived impact on quality of life. The 36-Item Short-Form (SF-36) Health Survey was administered as a measure of quality of life at 6 months postimplant. Standardized open-set speech recognition parameters were evaluated at 24 months postimplant. Vestibular function was determined by pre-and postimplant electronystagmography with caloric testing. The first author was blinded to implant type during data collection and analysis RESULTS Cochlear implantation yielded a significant 22% reduction in overall tinnitus handicap (p < .05). There was a 27% reduction in vestibular function that failed to show statistical significance (p = .78). There was no significant reduction in vestibular function postimplant in either group. The average open-set speech perception responses at 24 months postimplant were monosyllabic word recognition 45%, phoneme recognition 65%, and sentence recognition 86.5%. There was no significant difference with respect to implant type. Overall, 76% of implantees reported satisfaction with the amount of subjective benefit they received from their implants. Furthermore, 96% reported an overall positive impact on quality of life. CONCLUSION Overall, there was no significant difference between the two multichannel devices studied using the present software and hardware configurations.

Hearing loss following intratympanic instillation of gentamicin for the treatment of unilateral Meniere's disease.

OBJECTIVE To determine the incidence, extent, and time course of hearing loss following instillation of intratympanic gentamicin using a predetermined fixed protocol for incapacitating unilateral Menieres disease and to determine whether such loss is associated with any identifiable risk factors. STUDY DESIGN A retrospective analysis of all patients treated with intratympanic gentamicin between 1988 and 1998 using American Academy of Otolaryngology-Head and Neck Surgery reporting guidelines (1985 and 1995). A predetermined regimen using a fixed dose (gentamicin 26.7 mg/mL administered three times daily for 4 consecutive days) was used. METHODS The records of patients treated with this particular protocol were reviewed. The relationship between pretreatment hearing acuity, pretreatment bithermal caloric response, duration of symptoms, and previous treatment to post-treatment hearing were analyzed with respect to hearing. RESULTS Complete vestibular and audiologic data over a minimum 2-year follow-up were available for 85 individuals. Sixty-three patients (74.1%) had unchanged or improved hearing, and 22 patients (25.9%) realized hearing loss. In 80% of the latter, it occurred during the first month post-treatment. When hearing acuity at the 1-month post-treatment interval remained unchanged (91.1%), it was likely to remain so over the next 23 months. A significantly higher incidence of profound hearing loss was noted in patients who developed hearing loss in the first month, as compared with those who developed hearing loss at a later period (p = .0207, relative risk = 1.5). Re-treatment was not associated with hearing loss. The only identifiable risk factor for developing hearing loss was pretreatment hearing acuity stages 3 and 4 (pure-tone average > 40 dB) (p = .022, relative risk = 1.5). CONCLUSION Hearing loss is a recognized complication of treatment with intratympanic gentamicin, occurring in approximately 26% of individuals. In those individuals in whom hearing acuity has remained unchanged after the first month interval, significant worsening of hearing is unlikely, and patients can be reassured accordingly.