Quality of Life and Cost-Effectiveness of Cochlear Implants: A Narrative Review.

OBJECTIVES: To review evidence regarding the health-related quality of life (HRQoL) and cost-effectiveness of unilateral and bilateral cochlear implantation (CI) among children and adults with severe-to-profound hearing loss. STUDY DESIGN: Narrative review. METHODS: Publications related to quality of life (QoL) and costs of care in CI were acquired through searches in English-language databases. Studies were included if they had identified the HRQoL attainment, cost of care, cost-utility, or cost-effectiveness associated with CI. RESULTS: 57 studies were critically reviewed. The QoL outcome metrics used in these articles were divided into 2 categories - generic and condition specific. In studies investigating children, many reported no significant difference in QoL attainment between CI recipients and normal-hearing peers. In adults, significant improvements in QoL after implantation and higher QoL than in their nonimplanted (hearing-aided) peers were frequently reported. Studies involving an older adult cohort reported significant improvement in QoL after implantation, which was often independent of audiological performance. Overall, the calculated cost-utility ratios consistently met the threshold of cost acceptance, indicating acceptable values for expenditures on CI. CONCLUSIONS: Considerable work has been done on the QoL attainment and health economic implications of CI. Unilateral CI across all age groups leads to reported sustained benefits in the recipients' overall and disease-specific QoL. With increased cost associated with bilateral CI, further study is needed to characterize its costs and benefits with respect to the recipients' health, well-being, and contributions to society.

Mitigation of informational masking in individuals with single-sided deafness by integrated bone conduction hearing aids.

OBJECTIVES: To confirm an increased susceptibility to informational masking among individuals with single-sided deafness (SSD). To demonstrate a reduction in informational masking when SSD is treated with an integrated bone conduction hearing aid (IBC). To identify the acoustic cues that contribute to IBC-aided masking release. To determine the effects of device experience on the IBC advantage. DESIGN: Informational masking was evaluated with the coordinate-response measure. Participants performed the task by reporting color and number coordinates that changed randomly within target sentences. The target sentences were presented in free field accompanied by zero to three distracting sentences. Target and distracting sentences were spoken by different talkers and originated from different source locations, creating two sources of information for auditory streaming. Susceptibility to informational masking was inferred from the error rates of unaided SSD patients relative to normal controls. These baseline measures were derived by testing inexperienced IBC users without the device on the day of their initial fitting. The benefits of IBC-aided listening were assessed by measuring the aided performance of users who had at least 3 months' device experience. The acoustic basis of the listening advantage was isolated by correlating response errors with the voice pitch and location of distracting sentences. The effects of learning on cue effectiveness were evaluated by comparing the error rates of experienced and inexperienced users. RESULTS: Unaided SSD participants (inexperienced users) performed as well as normal controls when tested without distracting sentences but produced significantly higher error rates when tested with distracting sentences. Most errors involved responding with coordinates that were contained in distracting sentences. This increased susceptibility to informational masking was significantly reduced when experienced IBC users were tested with the device. The listening advantage was most strongly correlated with the availability of voice pitch cues, although performance was also influenced by the location of distracting sentences. Directional asymmetries appear to be dictated by location-dependent cues that are derived from the distinctive transmission characteristics of IBC stimulation. Experienced users made better use of these cues than inexperienced users. CONCLUSIONS: These results suggest that informational masking is a significant source of communication impairment among individuals with SSD. Despite the lateralization of auditory function, unaided SSD subjects experience informational masking when distractors occur in either the deaf or normal spatial hemifield. Restoration of aural sensitivity in the deaf hemifield with an IBC enhances speech intelligibility under complex listening conditions, presumably by providing additional sound-segregation cues that are derived from voice pitch and spatial location. The optimal use of these cues is not immediate, but a significant listening advantage is observed after 3 months of unstructured use.

Assessment of health-related quality of life 6 years after childhood cochlear implantation.

PURPOSE: To examine the impact of cochlear implant (CI) intervention on health-related quality of life (HRQOL) assessed by both self- and parent-reported measures. METHODS: In this national study of children implanted between ages 6 months and 5 years, HRQOL of 129 children 6-year post-CI was compared to 62 internal study (NH1) and 185 external (NH2) samples of hearing children frequency-matched to the CI group on sociodemographic variables. HRQOL ratings of children and their parents in each group, measured using the Child Health and Illness Profile-Child Edition, were compared, and their associations with the Family Stress Scale were investigated. RESULTS: CI children reported overall and domain-specific HRQOL that was comparable to both NH1 and NH2 peers. CI parents reported worse child scores than NH1 parents in Achievement, Resilience, and Global score (p's < 0.01) but similar or better scores than socioeconomically comparable NH2 parents. Higher family stress was negatively associated with all parent-reported HRQOL outcomes (p's < 0.01). Parent-child correlations in HRQOL global scores trended higher in CI recipients (r = 0.50) than NH1 (r = 0.42) and NH2 (r = 0.35) controls. CONCLUSIONS: CI recipients report HRQOL comparable to NH peers. These results, from both child and parent perspective, lend support to the effectiveness of CI intervention in mitigating the impact of early childhood deafness. Family stress was associated with worse HRQOL, underscoring a potential therapeutic target. Parent-child agreement in HRQOL scores was higher for CI families than NH families, which may reflect higher caregiver insight and involvement related to the CI intervention.

Effects of maternal sensitivity and cognitive and linguistic stimulation on cochlear implant users' language development over four years.

OBJECTIVES: To examine the effects of observed maternal sensitivity (MS), cognitive stimulation (CS), and linguistic stimulation on the 4-year growth of oral language in young, deaf children receiving a cochlear implant. Previous studies of cochlear implants have not considered the effects of parental behaviors on language outcomes. STUDY DESIGN: In this prospective, multisite study, we evaluated parent-child interactions during structured and unstructured play tasks and their effects on oral language development in 188 deaf children receiving a cochlear implant and 97 normal-hearing children as controls. Parent-child interactions were rated on a 7-point scale using the National Institute of Child Health and Human Development's Early Childcare Study codes, which have well-established psychometric properties. Language was assessed using the MacArthur Bates Communicative Development Inventories, the Reynell Developmental Language Scales, and the Comprehensive Assessment of Spoken Language. RESULTS: We used mixed longitudinal modeling to test our hypotheses. After accounting for early hearing experience and child and family demographics, MS and CS predicted significant increases in the growth of oral language. Linguistic stimulation was related to language growth only in the context of high MS. CONCLUSION: The magnitude of effects of MS and CS on the growth of language was similar to that found for age at cochlear implantation, suggesting that addressing parenting behaviors is a critical target for early language learning after implantation.

Age-dependent cost-utility of pediatric cochlear implantation.

OBJECTIVES: Cochlear implantation (CI) has become the mainstay of treatment for children with severe-to-profound sensorineural hearing loss (SNHL). Yet, despite mounting evidence of the clinical benefits of early implantation, little data are available on the long-term societal benefits and comparative effectiveness of this procedure across various ages of implantation-a choice parameter for parents and clinicians with high prognostic value for clinical outcome. As such, the aim of the present study is to evaluate a model of the consequences of the timing of this intervention from a societal economic perspective. Average cost utility of pediatric CI by age at intervention will be analyzed. DESIGN: Prospective, longitudinal assessment of health utility and educational placement outcomes in 175 children recruited from six U.S. centers between November 2002 and December 2004, who had severe-to-profound SNHL onset within 1 year of age, underwent CI before 5 years of age, and had up to 6 years of postimplant follow-up that ended in November 2008 to December 2011. Costs of care were collected retrospectively and stratified by preoperative, operative, and postoperative expenditures. Incremental costs and benefits of implantation were compared among the three age groups and relative to a nonimplantation baseline. RESULTS: Children implanted at <18 months of age gained an average of 10.7 quality-adjusted life years (QALYs) over their projected lifetime as compared with 9.0 and 8.4 QALYs for those implanted between 18 and 36 months and at >36 months of age, respectively. Medical and surgical complication rates were not significantly different among the three age groups. In addition, mean lifetime costs of implantation were similar among the three groups, at approximately $2000/child/year (77.5-year life expectancy), yielding costs of $14,996, $17,849, and $19,173 per QALY for the youngest, middle, and oldest implant age groups, respectively. Full mainstream classroom integration rate was significantly higher in the youngest group at 81% as compared with 57 and 63% for the middle and oldest groups, respectively (p < 0.05) after 6 years of follow-up. After incorporating lifetime educational cost savings, CI led to net societal savings of $31,252, $10,217, and $6,680 for the youngest, middle, and oldest groups at CI, respectively, over the child's projected lifetime. CONCLUSIONS: Even without considering improvements in lifetime earnings, the overall cost-utility results indicate highly favorable ratios. Early (<18 months) intervention with CI was associated with greater and longer quality-of-life improvements, similar direct costs of implantation, and economically valuable improved classroom placement, without a greater incidence of medical and surgical complications when compared to CI at older ages.

Influence of implantation age on school-age language performance in pediatric cochlear implant users.

OBJECTIVE: This study examined specific spoken language abilities of 160 children with severe-to-profound sensorineural hearing loss followed prospectively 4, 5, or 6 years after cochlear implantation. STUDY SAMPLE: Ninety-eight children received implants before 2.5 years, and 62 children received implants between 2.5 and 5 years of age. DESIGN: Language was assessed using four subtests of the Comprehensive Assessment of Spoken Language (CASL). Standard scores were evaluated by contrasting age of implantation and follow-up test time. RESULTS: Children implanted under 2.5 years of age achieved higher standard scores than children with older ages of implantation for expressive vocabulary, expressive syntax, and pragmatic judgments. However, in both groups, some children performed more than two standard deviations below the standardization group mean, while some scored at or well above the mean. CONCLUSIONS: Younger ages of implantation are associated with higher levels of performance, while later ages of implantation are associated with higher probabilities of continued language delays, particularly within subdomains of grammar and pragmatics. Longitudinal data from this cohort study demonstrate that after 6 years of implant experience, there is large variability in language outcomes associated with modifiers of rates of language learning that differ as children with implants age.

Estimating the effect of occupational noise exposure on hearing thresholds: the importance of adjusting for confounding variables.

OBJECTIVES: To evaluate whether valid estimation of the effect of occupational noise exposure on hearing thresholds requires adjustment for factors other than age, sex, and race, which also influence hearing function. DESIGN: Multivariate regression analyses were performed in the 1999-2002 National Health and Nutrition Examination Survey (N = 3527). RESULTS: Occupational noise exposure was significantly associated with educational level, leisure time and firearm noise, and smoking. Incomplete adjustment for these factors leads to an overestimation of the effect of occupational noise exposure. CONCLUSIONS: Current methods of estimating the effect of occupational noise exposure (e.g., Annex C of American National Standards Institute S3.44) require better consideration of these confounding factors.

Spoken language development in children following cochlear implantation.

CONTEXT: Cochlear implantation is a surgical alternative to traditional amplification (hearing aids) that can facilitate spoken language development in young children with severe to profound sensorineural hearing loss (SNHL). OBJECTIVE: To prospectively assess spoken language acquisition following cochlear implantation in young children. DESIGN, SETTING, AND PARTICIPANTS: Prospective, longitudinal, and multidimensional assessment of spoken language development over a 3-year period in children who underwent cochlear implantation before 5 years of age (n = 188) from 6 US centers and hearing children of similar ages (n = 97) from 2 preschools recruited between November 2002 and December 2004. Follow-up completed between November 2005 and May 2008. MAIN OUTCOME MEASURES: Performance on measures of spoken language comprehension and expression (Reynell Developmental Language Scales). RESULTS: Children undergoing cochlear implantation showed greater improvement in spoken language performance (10.4; 95% confidence interval [CI], 9.6-11.2 points per year in comprehension; 8.4; 95% CI, 7.8-9.0 in expression) than would be predicted by their preimplantation baseline scores (5.4; 95% CI, 4.1-6.7, comprehension; 5.8; 95% CI, 4.6-7.0, expression), although mean scores were not restored to age-appropriate levels after 3 years. Younger age at cochlear implantation was associated with significantly steeper rate increases in comprehension (1.1; 95% CI, 0.5-1.7 points per year younger) and expression (1.0; 95% CI, 0.6-1.5 points per year younger). Similarly, each 1-year shorter history of hearing deficit was associated with steeper rate increases in comprehension (0.8; 95% CI, 0.2-1.2 points per year shorter) and expression (0.6; 95% CI, 0.2-1.0 points per year shorter). In multivariable analyses, greater residual hearing prior to cochlear implantation, higher ratings of parent-child interactions, and higher socioeconomic status were associated with greater rates of improvement in comprehension and expression. CONCLUSION: The use of cochlear implants in young children was associated with better spoken language learning than would be predicted from their preimplantation scores.

Predicting behavior problems in deaf and hearing children: the influences of language, attention, and parent-child communication.

The development of language and communication may play an important role in the emergence of behavioral problems in young children, but they are rarely included in predictive models of behavioral development. In this study, cross-sectional relationships between language, attention, and behavior problems were examined using parent report, videotaped observations, and performance measures in a sample of 116 severely and profoundly deaf and 69 normally hearing children ages 1.5 to 5 years. Secondary analyses were performed on data collected as part of the Childhood Development After Cochlear Implantation Study, funded by the National Institutes of Health. Hearing-impaired children showed more language, attention, and behavioral difficulties, and spent less time communicating with their parents than normally hearing children. Structural equation modeling indicated there were significant relationships between language, attention, and child behavior problems. Language was associated with behavior problems both directly and indirectly through effects on attention. Amount of parent-child communication was not related to behavior problems.

Electric charge requirements of pediatric cochlear implant recipients enrolled in the Childhood Development After Cochlear Implantation study.

OBJECTIVE: To evaluate mapping characteristics of children with cochlear implants who are enrolled in the Childhood Development After Cochlear Implantation (CDACI) multicenter study. STUDY DESIGN: Longitudinal evaluation during 24 months of speech processor maps of children with cochlear implants prospectively enrolled in the study. SETTING: Six tertiary referral centers. SUBJECTS: One hundred eighty-eight children enrolled in the CDACI study who were 5 years old or younger at the time of enrollment. Of these children, 184 received unilateral implants, and 4 received simultaneous bilateral implants. INTERVENTION: Children attended regular mapping sessions at their implant clinic as part of the study protocol. Maps were examined for each subject at 4 different time intervals: at device activation and 6, 12, and 24 months postactivation. MAIN OUTCOME MEASURES: Mean C/M levels (in charge per phase) were compared for 4 different time intervals, for 3 different devices, for 6 different implant centers, and for children with normal and abnormal cochleae. RESULTS: All 3 types of implant devices demonstrate significant increases in C/M levels between device activation and the 24-month appointment. Significant differences in mean C/M levels were noted between devices. Children with cochlear anomalies demonstrate significantly greater C/M levels than children with normal cochleae. CONCLUSION: The CDACI study has enabled us to evaluate the mapping characteristics of pediatric patients who use 3 different devices and were implanted at a variety of implant centers. Analysis of such data enables us to better understand the mapping characteristics of children with cochlear implants.

Assessing the use of speech and language measures in relation to parental perceptions of development after early cochlear implantation.

OBJECTIVE: Clinicians and investigators use multiple outcome measures after early cochlear implantation (CI) to assess auditory skills, speech, and language effects. Are certain outcome measures better associated with optimal childhood development from the perspective of parents? We studied the association between several commonly used outcome instruments and a measure of parental perceptions of development to gain insight into how our clinical tests reflect parental perceptions of a child's developmental status. STUDY DESIGN: Cross-sectional analysis. SETTING: Six academic centers. PATIENTS: One hundred eighty-eight deaf children (<6 yr) 1 year after CI activation enrolled in the longitudinal Childhood Development after CI study. MAIN OUTCOME MEASURES: Measures of auditory skills, speech, and language. Parental perceptions of development quantified with a visual analogue scale (visual analogue scale-development). METHODS: Nonparametric and parametric regression methods were used to model the relationship between outcome measures and visual analogue scale-development scores. RESULTS: All outcome measures were positively associated with parental perceptions of development, but more robust associations were observed with language measures and a parent-report scale of auditory skills than with a selected measure of closed-set speech. For speech and language data, differences were observed in the trajectories of associations among younger (2-3 yr) versus older (4-5 yr) children. CONCLUSION: Our results demonstrate the importance of measuring multiple outcome measures after early pediatric CI. The degree to which an outcome measure reflects childhood development as perceived by parents may be affected by the child's age. Measures that are based on parental report and broader outcome measures focused on verbal language offer the potential for a fuller understanding of the true effectiveness of early implantation.

Surgical factors in pediatric cochlear implantation and their early effects on electrode activation and functional outcomes.

OBJECTIVE: To assess the impact of surgical factors on electrode status and early communication outcomes in young children in the first 2 years of cochlear implantation. STUDY DESIGN: Prospective multicenter cohort study. SETTING: Six tertiary referral centers. PATIENTS: Children 5 years or younger before implantation with normal nonverbal intelligence. INTERVENTION: Cochlear implant operations in 209 ears of 188 children. MAIN OUTCOME MEASURES: Percent active channels, auditory behavior as measured by the Infant Toddler Meaningful Auditory Integration Scale/Meaningful Auditory Integration Scale and Reynell receptive language scores. RESULTS: Stable insertion of the full electrode array was accomplished in 96.2% of ears. At least 75% of electrode channels were active in 88% of ears. Electrode deactivation had a significant negative effect on Infant Toddler Meaningful Auditory Integration Scale/Meaningful Auditory Integration Scale scores at 24 months but no effect on receptive language scores. Significantly fewer active electrodes were associated with a history of meningitis. Surgical complications requiring additional hospitalization and/or revision surgery occurred in 6.7% of patients but had no measurable effect on the development of auditory behavior within the first 2 years. Negative, although insignificant, associations were observed between the need for perioperative revision of the device and 1) the percent of active electrodes and 2) the receptive language level at 2-year follow-up. CONCLUSION: Activation of the entire electrode array is associated with better early auditory outcomes. Decrements in the number of active electrodes and lower gains of receptive language after manipulation of the newly implanted device were not statistically significant but may be clinically relevant, underscoring the importance of surgical technique and the effective placement of the electrode array.

Tracking development of speech recognition: longitudinal data from hierarchical assessments in the Childhood Development after Cochlear Implantation Study.

OBJECTIVE: To develop a speech recognition index that summarizes data collected through an array of age-appropriate hierarchical speech recognition tests in a longitudinal study. STUDY DESIGN: Prospective cohort. SETTING: Six tertiary referral centers in the Childhood Development after Cochlear Implantation (CDaCI) Study. PATIENTS: One hundred eighty-eight children implanted at age 5 years or younger and 97 age-comparable normal-hearing controls. INTERVENTION: Cochlear implantation. MAIN OUTCOME MEASURES: Outcome measures were the following: Infant-Toddler Meaningful Auditory Integration Scale, Meaningful Auditory Integration Scale, Early Speech Perception Test, Pediatric Speech Intelligibility Test, Multisyllabic Lexical Neighborhood Test, Lexical Neighborhood Test, and Hearing in Noise Test, obtained before implantation and at 6, 12, 18, and 24 months postimplant. RESULTS: A speech recognition cumulative index, speech recognition index in quiet (SRI-Q), was created to combine information from tests administered in quiet. This index allows simultaneous display of data from all tests in the speech recognition hierarchy and is sensitive to improvements in performance over time as a function of age. SRI-Q also provides a composite of performance on multiple tests, allowing both the tracking of "growth curve" in speech recognition across a wide age range over an extended follow-up period and the comparison of normal-hearing and implanted children on multiple measures. The data range for individual tests is also preserved for ease of interpretation. CONCLUSION: SRI-Q allows tracking of global development of speech recognition over time as children progress through a hierarchy of speech perception measures and complements the more detailed assessments obtained from individual tests within the hierarchy.

Assessment of changes in cochlear function with pneumolabyrinth after middle ear trauma.

OBJECTIVE: To describe a case of pneumolabyrinth secondary to tympanic membrane/ossicular trauma and the subsequent recovery of sensorineural hearing loss managed with conservative measures. PATIENTS: A 15-year-old boy presented to an outside hospital with signs and symptoms of acute hearing loss, vertigo, and tinnitus after penetrating injury to his right tympanic membrane. In addition, computed tomography demonstrated air density within the vestibule. INTERVENTIONS: The patient was managed conservatively with bed rest, avoidance of straining, corticosteroids, and antibiotics. MAIN OUTCOME MEASURES: Computed tomography, audiologic testing. RESULTS: Patient recovered near-normal hearing subjectively. There was closure of the air-bone gap (

Childhood Development after Cochlear Implantation (CDaCI) study: design and baseline characteristics.

Children with severe to profound sensorineural hearing loss face communication challenges that influence language, psychosocial and scholastic performance. Clinical studies over the past 20 years have supported wider application of cochlear implants in children. The Childhood Development after Cochlear Implantation (CDaCI) study is the first longitudinal multicentre, national cohort study to evaluate systematically early cochlear implant (CI) outcomes in children. The objective of the study was to compare children who have undergone cochlear implantation, with similarly aged hearing peers across multiple domains, including oral language development, auditory performance, psychosocial and behavioural functioning, and quality of life. The CDaCI study is a multicentre national cohort study of CI children and normal hearing (NH) peers. Eligibility criteria include informed consent, age less than 5 years, pre- or post-lingually deaf, developmental criteria met, commitment to educate the child in English and bilateral cochlear implants. All children had a standardised baseline assessment that included demographics, hearing and medical history, communication history, language measures, cognitive tests, speech recognition, an audiological exam, psychosocial assessment including parent-child videotapes and parent reported quality of life. Follow-up visits are scheduled at six-month intervals and include a standardised assessment of the full battery of measures. Quality assurance activities were incorporated into the design of the study. A total of 188 CI children and 97 NH peers were enrolled between November 2002 and December 2004. The mean age, gender and race of the CI and NH children are comparable. With regard to parental demographics, the CI and NH children's families are statistically different. The parents of CI children are younger, and not as well educated, with 49% of CI parents reporting college graduation vs. 84% of the NH parents. The income of the CI parents is also lower than the NH parents. Assessments of cognition suggest that there may be baseline differences between the CI and NH children; however the scores were high enough to suggest language learning potential. The observed group differences identified these baseline characteristics as potential confounders which may require adjustment in analyses of outcomes. This longitudinal cohort study addresses questions related to high variability in language outcomes. Identifying sources of that variance requires research designs that: characterise potential predictors with accuracy, use samples that adequately power a study, and employ controls and approaches to analysis that limit bias and error. The CDaCI study was designed to generate a more complete picture of the interactive processes of language learning after implantation.

Ultra-High-Field Magnetic Resonance Imaging of the Human Inner Ear at 11.7 Tesla.

OBJECTIVE: To evaluate the ability of ultra-high-field magnetic resonance imaging (UHF-MRI) at 11.7 T to visualize membranous structures of the human inner ear. SPECIMENS: Three temporal bones were extracted from cadaveric human heads for use with small-bore UHF-MRI. INTERVENTION: Ex vivo cadaveric temporal bone specimens were imaged using an 11.7 T magnetic resonance imaging (MRI) scanner via T1- and T2-weighted-imaging with and without contrast. MAIN OUTCOME MEASURE: Qualitative visualization of membranous components of the inner ear compared with reports of UHF-MRI at lower field strengths. RESULTS: The membranous anatomy of the inner ear was superbly visualized at 11.7 T. In the cochlea, Reissner's membrane, the scala media, and the basilar membrane were clearly shown on the scan. In the vestibular labyrinth, the wedge-shaped crista ampullaris and the maculae of both the saccule and utricle were visible. Details of the endolymphatic sac and duct were also demonstrated. CONCLUSION: To our knowledge, this report presents the first images of the ex vivo human inner ear using 11.7 T UHF-MRI, offering near-histologic resolution. Increased field strength may be particularly useful when imaging the delicate membranous anatomy of the inner ear. Further research on the use of UHF-MRI in clinical and research settings could illuminate structural changes associated with inner ear disorders.

Amplification in the rehabilitation of unilateral deafness: speech in noise and directional hearing effects with bone-anchored hearing and contralateral routing of signal amplification.

OBJECTIVE: Vibromechanical stimulation with a semi-implantable bone conductor (Entific BAHA device) overcomes some of the head-shadow effects in unilateral deafness. What specific rehabilitative benefits are observed when the functional ear exhibits normal hearing versus moderate sensorineural hearing loss (SNHL)? DESIGN: The authors conducted a prospective trial of subjects with unilateral deafness in a tertiary care center. PATIENTS: This study comprised adults with unilateral deafness (pure-tone average [PTA] > 90 dB; Sp.D. < 20%) and either normal monaural hearing (n = 18) or moderate SNHL (PTA = 25-50 dB: Sp.D. > 75%) in the contralateral functional ear (n = 5). INTERVENTIONS: Subjects were fit with contralateral routing of signal (CROS) devices for 1 month and tested before (mastoid) implantation, fitting, and testing with a bone-anchored hearing aid (BAHA). OUTCOME MEASURES: Outcome measures were: 1) subjective benefit; 2) source localization tests (Source Azimuth Identification in Noise Test [SAINT]); 3) speech discrimination in quiet and in noise assessed with Hearing In Noise Test (HINT) protocols. RESULTS: There was consistent satisfaction with BAHA amplification and poor acceptance of CROS amplification. General directional hearing decreased with CROS use and was unchanged by BAHA and directional microphone aids. Relative to baseline and CROS, BAHA produced significantly better speech recognition in noise. Twenty-two of 23 subjects followed up in this study continue to use their BAHA device over an average follow-up period of 30.24 months (range, 51-12 months). CONCLUSION: BAHA amplification on the side of a deaf ear yields greater benefit in subjects with monaural hearing than does CROS amplification. Advantages likely related to averting the interference of speech signals delivered to the better ear, as occurs with conventional CROS amplification, while alleviating the negative head-shadow effects of unilateral deafness. The advantages of head-shadow reduction in enhancing speech recognition with noise in the hearing ear outweigh disadvantages inherent in head-shadow reduction that can occur by introducing noise from the deaf side. The level of hearing impairment correlates with incremental benefit provided by the BAHA. Patients with a moderate SNHL in the functioning ear perceived greater increments in benefit, especially in background noise, and demonstrated greater improvements in speech understanding with BAHA amplification.

Microsatellite analysis of recurrent vestibular schwannoma (acoustic neuroma) following stereotactic radiosurgery.

HYPOTHESIS: Genetic and immunohistochemical studies may provide insight into the mechanisms of vestibular schwannoma (VS) recurrence following radiation therapy. BACKGROUND: Stereotactic radiation therapy is an increasingly common alternative to microsurgical resection for the primary management of sporadic VS. The molecular mechanisms associated with recurrent vestibular schwannoma (VS) following radiation therapy are not known. METHODS: Primary or irradiated VS tumors were fresh-frozen at the time of surgical resection and microdissected to undergo DNA extraction. Lymphocytic control DNA was isolated from blood obtained by venipuncture. Paired normal and tumor DNA specimens were analyzed for allelic loss by PCR amplification of polymorphic dinucleotide repeat sequences. Immunohistochemical studies were performed on paraffin-embedded, irradiated surgical specimens. RESULTS: Using 16 polymorphic microsatellite markers, 20 of 26 non-irradiated VS demonstrated loss of heterozygosity (LOH) in at least one locus of chromosome 22q. In contrast, none of the four irradiated recurrent VS demonstrated LOH on chromosome 22q (p = 0.008). No allelic loss was seen in either the primary or irradiated VS utilizing markers mapping to chromosome 10. Deletions on chromosome 10 are seen in both benign and higher-grade meningiomas and intracranial malignancies associated with radiotherapy. Immunohistochemical studies were performed to detect the protein product of the NF2 gene, merlin, in the four irradiated VS. NF2 staining was not observed. CONCLUSION: This study represents the first microsatellite and immunohistochemical analysis of recurrent VS following radiation therapy. Our preliminary observations suggest an alternative mechanism of NF2 inactivation that may correlate with radioresistance in VS.

Cochlear implantation in patients with neurofibromatosis type 2 and bilateral vestibular schwannoma.

OBJECTIVE: To investigate the results of cochlear implantation in patients with neurofibromatosis Type 2 (NF2) and bilateral vestibular schwannoma. STUDY DESIGN: Retrospective case review. SETTING: Three academic tertiary referral centers. PATIENTS: Seven patients with NF2 and bilateral vestibular schwannoma who lost hearing in at least one ear after treatment of their tumor (surgery or radiation therapy). INTERVENTION: Cochlear implantation after treatment of their vestibular schwannoma. MAIN OUTCOME MEASURE: Postimplantation audiometric scores (pure-tone average thresholds, consonant-nucleus-consonant (CNC) words/phonemes, Central Institute for the Deaf (CID) sentences, Hearing in Noise Test (HINT) quiet/noise, and Monosyllable, Trochee, Spondee (MTS) recognition/category tests), patient satisfaction, and device use patterns. RESULTS: The average age at implantation was 40 years (range, 16-57 yr). Follow-up ranged from 6 to 88 months after implantation. Three patients were implanted with residual useful hearing in the contralateral ear, whereas four patients had no hearing in the contralateral ear. Hearing loss was due to surgical excision of tumor (n=5) or gamma-knife radiotherapy (n=2). Postactivation pure-tone average thresholds in the implanted ear ranged from 30 to 55 dB (average, 32.5 dB), although speech reception testing varied considerably among subjects. Despite this variability, all patients continue to use the device on a daily basis. CONCLUSION: In selected cases of deafness in patients with NF2 where there has been anatomic preservation of the auditory nerve after acoustic neuroma resection or radiation therapy, cochlear implantation may offer some improvement in communication skills, including the possibility of open-set speech communication in some patients. These results compare favorably to the auditory brainstem implant offering an alternative for hearing rehabilitation in patients with NF2.

Measuring health-related quality of life after pediatric cochlear implantation: a systematic review.

OBJECTIVE: The measurement of health-related quality of life (HRQL) in children presents conceptual and methodological challenges owing to the multidimensionality of the required information and limitations in patient self-report. HRQL results provide a broad measure of treatment impact from the patient and family perspective and are crucial to guiding clinical and policy decisions. The objective of this study was to evaluate how HRQL in children with cochlear implants has been measured in published studies in order to draw conclusions that could inform future investigations of this area of clinical research. METHODS: We searched PubMed, EMBASE, CINAHL, PsychoInfo, and Web of Science databases using a defined search string and hand-searched reference lists of relevant articles and personal files. Retrieved citations were reviewed in two stages, a title and abstract screen followed by review of the full-length article. Inclusion criteria for studies were: (1) original peer-reviewed research article; (2) enrolled subjects <18 years old with cochlear implants; (3) use of a HRQL instrument that incorporated components of physical, mental, and social health; and (4) in English. Data from full-length articles were extracted by a single-investigator. RESULTS: We retrieved 671 citations with our search strategy, and 10 citations were found to be eligible for inclusion. All studies used a cross-sectional design, and three types of HRQL instruments were used: generic questionnaires, ad hoc instruments designed specifically for the purposes of the study, and the parents views and experiences with pediatric CI questionnaire. Heterogeneity in study design and instruments prevented a quantitative, meta-analysis of the data. CONCLUSIONS: Studies that used well-validated, generic HRQL instruments supported conclusions that were less subject to potential bias from the perspective of the clinician investigator. Most studies did not use well-defined cohorts with respect to age at implantation and duration of implant use, and conclusions in these studies were also subject to potential bias. No well-validated, deafness-specific HRQL instruments are currently available. Future research should be done with existing, generic HRQL instruments and with strict study inclusion criteria. Suggested generic HRQL instruments are discussed.