Clinical Outcomes of the Cochlear™ Nucleus(®) 5 Cochlear Implant System and SmartSound™ 2 Signal Processing.

BACKGROUND: While published data exist regarding cochlear implant (CI) outcomes from large academic programs, evidence of benefit based on national, multicenter clinical trials is needed for information regarding typical patient outcomes of devices implanted by U.S. centers representing larger academic to smaller hospital-based programs. PURPOSE: This nationwide trial evaluated outcomes in a group of newly implanted adult recipients of the Cochlear™ Nucleus(®) 5 CI system and SmartSound™ 2 signal processing. Unlike previous clinical trials, the AzBio sentence test was used and represents recent transition in our field to use of more challenging test materials. It was hypothesized that (1) speech perception scores in quiet with SmartSound™ 2 signal processing would not be statistically different from previous-generation devices; (2) speech perception scores in noise with SmartSound™ 2 signal processing would be better with enhanced microphone directionality; (3) speech perception scores in noise will be better with the preferred SmartSound™ 2 program for listening in noise; and (4) cochlear implantation would improve quality of life as assessed by the updated Health Utility Index Mark 3 (HUI3). A secondary purpose was to examine the relationships among the current and previously used speech perception tests of the Minimum Speech Test Battery (MSTB). It was hypothesized that speech perception scores within the same test interval would show predictive relationships. RESEARCH DESIGN: Prospective, single-arm, repeated-measures study across 13 CI centers in the United States between February 2010 and June 2012. The participating centers ranged from larger academic to smaller hospital-based programs to accurately represent the diversity of programs in the United States. STUDY SAMPLE: Participants were 38 postlingually deafened adult CI candidates. DATA COLLECTION AND ANALYSIS: Primary measures were Consonant-Nucleus-Consonant (CNC) words in quiet and the AzBio Sentence Test in Quiet (AzBioQ) and in Noise (AzBioN) tested at preoperative, and 3-, 6-, and 12-mo postactivation intervals. Quality of life was measured with the HUI3. For the secondary objective, statistical analyses were performed to investigate the predictive properties between current and previously used MSTB tests. RESULTS: Mean CNC scores were significantly higher compared to the Nucleus(®) 24 Contour™ at 3 mo (p < 0.05) postactivation and showed no difference compared to the Nucleus(®) Freedom™ at 6 mo postactivation. Both SmartSound™ 2 FOCUS and NOISE programs provided significant improvements in performance in noise over the EVERYDAY program (p < 0.001), and performance with the FOCUS program was significantly better compared to the NOISE program (p < 0.001). Speech perception in noise was not related to patients' subjective program preferences. Quality-of-life outcomes showed significant improvements from the preoperative to 6-mo postactivation interval (p < 0.05-0.001). Strong and significant correlations were found between preoperative CNC and AzBioQ and preoperative Hearing-in-Noise Test sentences in Quiet (HINTQ) and AzBioQ. At 12-mo postactivation, there were strong and highly significant correlations between CNC and AzBioQ, HINTQ and AzBioQ, and Hearing-in-Noise Test sentences in Noise and AzBioN (all p < 0.001). CONCLUSIONS: Results of this national clinical trial showed significant improvements in speech perception and quality of life following cochlear implantation. SmartSound™ 2 signal processing features showed a significant benefit of FOCUS when listening in noise, although preference of signal processing feature did not correlate with performance. Significant correlations were observed between speech perception tests. The findings of this study can be applied in clinical assessment, programming, and follow-up for CI candidates and recipients.

The role of age on cochlear implant performance, use, and health utility: a multicenter clinical trial.

OBJECTIVE: To use data obtained in a multicenter clinical trial to evaluate factors affecting performance with an implant, with special emphasis on the effect of age on performance. STUDY DESIGN AND SETTING: Post hoc analyses of data collected during a multicenter prospective study to evaluate performance with a recently introduced cochlear implant (CI) system conducted at 13 academic centers in the United States. Subjects participated in speech recognition testing in quiet and noise and completed questionnaires regarding health utility and processor use. PATIENTS: Thirty-eight adults with moderate to profound hearing loss who ranged in age from 18 to 89 years. Subjects were divided into younger (<65 yr, n = 20) and older (≥65 yr, n = 18) groups for the analyses. INTERVENTION: All subjects received a multichannel CI system. Preimplant to postimplant change in speech recognition was evaluated for each group, and the performance of the two groups was compared. Postimplant performance of older subjects who scored greater than 40% preimplant on HINT (Hearing in Noise Test) sentences was also evaluated. Linear regression was used to further evaluate the effects of variables on outcomes. RESULTS: Both younger and older subjects demonstrated significant improvement in speech recognition and hearing health utility after receiving a CI, and differences between groups were insignificant. Older subjects who scored greater than 40% preoperatively on HINT sentences demonstrated a significant improvement in speech recognition. CONCLUSION: Both older and younger patients can receive significant improvement in speech recognition and health utility after receiving a CI.

Assessment of cochlear implant candidacy in patients with cochlear nerve deficiency using the P1 CAEP biomarker.

OBJECTIVE: The goal of this report was to ascertain the efficacy of the P1 cortical auditory evoked potential (CAEP) biomarker as an objective tool to assist in the evaluation of cochlear implant (CI) candidacy in children with a radiological diagnosis of cochlear nerve deficiency (CND). METHODS: Retrospective case study review of audiological and radiological findings was performed in four pediatric patients identified with CND and severe-to-profound sensorineural hearing loss. Cortical auditory evoked potential testing was conducted, and the presence and latency of the P1 component were analyzed. RESULTS: Three out of four children demonstrated robust P1 CAEP responses, indicating activation of the central auditory pathways by auditory stimulation, despite the diagnosis of CND. These children were considered good candidates for cochlear implantation. DISCUSSION: Although cochlear implantation in children is a fairly routine procedure, cases exist for which implant candidacy is questionable. Among these cases are children with CND. In these children, cochlear implantation may be contraindicated due to the likelihood that the implant electrodes may not stimulate the VIII nerve adequately. Magnetic resonance imaging (MRI) is considered the gold standard in the assessment of CND, but this measure is not always sufficient to determine CI candidacy in cases of CND. The addition of the P1 CAEP measurement to the usual electrophysiological, audiometric, and radiological test battery may prove to be useful in determining CI options for children with CND.

Cortical maturation and behavioral outcomes in children with auditory neuropathy spectrum disorder.

UNLABELLED: OBJECTIVE. Auditory neuropathy spectrum disorder (ANSD) affects approximately 10% of patients with sensorineural hearing loss. While many studies report abnormalities at the level of the cochlea, auditory nerve, and brainstem in children with ANSD, much less is known about their cortical development. We examined central auditory maturation in 21 children with ANSD. DESIGN. Morphology, latency and amplitude of the P1 cortical auditory evoked potential (CAEP) were used to assess auditory cortical maturation. Children's scores on a measure of auditory skill development (IT-MAIS) were correlated with CAEPs. Study Sample. Participants were 21 children with ANSD. All were hearing aid users. RESULT: Children with ANSD exhibited differences in central auditory maturation. Overall, two-thirds of children revealed present P1 CAEP responses. Of these, just over one third (38%) showed normal P1 response morphology, latency and amplitude, while another third (33%) showed delayed P1 response latencies and significantly smaller amplitudes. The remaining children (29%) revealed abnormal or absent P1 responses. Overall, P1 responses were significantly correlated with auditory skill development. CONCLUSION: Our results suggest that P1 CAEP responses may be: (i) A useful indicator of the extent to which neural dys-synchrony disrupts cortical development, (ii) A good predictor of behavioral outcome in children with ANSD.