Browsing by keyword "*Cochlear Implants"
Now showing items 1-4 of 4
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Cochlear implant electrode failure secondary to silicone touch-up during device manufacturingSTUDY DESIGN: Retrospective case report. SETTING: Tertiary referral cochlear implant center. PATIENT: A 21-year-old woman was implanted with Advanced Bionics HiFocus Clarion device without complication. Five years later, the patient presented with dizziness, fluctuating implant performance, and facial pain. INTERVENTION: Surgical exploration revealed a torn electrode silicon casing in conjunction with scar contraction bending the electrode against bony facial nerve canal at the facial recess. Suspension of the electrode such that the damaged portion was not in contact with mastoid cavity led to temporary resolution of symptoms. Explantation and reimplantation procedures were carried out 2 months later. RESULTS: Postexplantation device analysis by the manufacturer demonstrated silicone touch-up at the site of failure. Six years since reimplantation, the patient has remained symptom-free. It is very likely that the touch-up silicon weakened the electrode and, in conjunction with chronic scar contraction, led to the tear on the silicon casing. CONCLUSION: Isolated cochlear implant electrode failure is a rare but possible long-term complication in older generation devices. The author reports 1 case of implant device failure partly because of silicon touch-up that was applied at the location of electrode failure during its manufacturing process.
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Determining cochlear implant users' true noise tolerance: use of speech reception threshold in noise testingOBJECTIVE: The speech perception abilities of cochlear implant (CI) recipients have significantly improved over the past decade. At the same time, clinical test batteries to measure their performance in noise remain mostly unchanged, resulting in ceiling-level performance for the most successful recipients. The goal of this study is to determine the true noise tolerance abilities of CI recipients using adaptive speech reception threshold (SRT) in noise testing. STUDY DESIGN: Prospective clinical study. SETTING: Tertiary care hospital; CI program. PATIENTS: Ten CI users, either unilateral or bilateral, with HINT scores that equaled or exceeded 80% when administered with a fixed +10 dB signal-to-noise (SNR) ratio (i.e., HINT(+10dB)). INTERVENTION: The HINT with adaptive SNR levels and QuickSIN test were administered to measure noise tolerance at speech thresholds where 50% of the stimuli were correctly perceived. MAIN OUTCOME MEASURE(S): SRTs were measured for both the adaptive SNR HINT (i.e., HINT(50%)) and the QuickSIN test. These SRTs were compared with the fixed noise level HINT(+10dB) scores as well as to CNC monosyllable word perception scores. RESULTS: Despite small variance in performance levels on the HINT(+10dB), results of the HINT(50%) ( approximately 16 dB range) and QuickSIN ( approximately 12 dB range) tests demonstrate significant differences in noise tolerance levels among these CI recipients. CONCLUSION: For excellent CI users, use of adaptive speech threshold tests in noise better defines a user's actual ability to perceive speech than do fixed SNR level tests. SRT-in-noise tests have the advantage of being quick to administer, and the same stimuli can be used over a very wide range of performance levels. The use of adaptive SRT-in-noise tests should be considered a viable and valuable replacement of fixed SNR tests in the CI clinical test battery.
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Relational learning in children with deafness and cochlear implantsThis four-experiment series sought to evaluate the potential of children with neurosensory deafness and cochlear implants to exhibit auditory-visual and visual-visual stimulus equivalence relations within a matching-to-sample format. Twelve children who became deaf prior to acquiring language (prelingual) and four who became deaf afterwards (postlingual) were studied. All children learned auditory-visual conditional discriminations and nearly all showed emergent equivalence relations. Naming tests, conducted with a subset of the children, showed no consistent relationship to the equivalence-test outcomes. This study makes several contributions to the literature on stimulus equivalence. First, it demonstrates that both pre- and postlingually deaf children can acquire auditory-visual equivalence relations after cochlear implantation, thus demonstrating symbolic functioning. Second, it directs attention to a population that may be especially interesting for researchers seeking to analyze the relationship between speaker and listener repertoires. Third, it demonstrates the feasibility of conducting experimental studies of stimulus control processes within the limitations of a hospital, which these children must visit routinely for the maintenance of their cochlear implants.
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The influence of a sensitive period for auditory-visual integration in children with cochlear implantsPURPOSE: Children who experience long periods of auditory deprivation are susceptible to large-scale reorganization of auditory cortical areas responsible for the perception of speech and language. One consequence of this reorganization is that integration of combined auditory and visual information may be altered after hearing is restored with a cochlear implant. Our goal was to investigate the effects of reorganization in a task that examines performance during multisensory integration. METHODS: Reaction times to the detection of basic auditory (A), visual (V), and combined auditory-visual (AV) stimuli were examined in a group of normally hearing children, and in two groups of cochlear implanted children: (1) early implanted children in whom cortical auditory evoked potentials (CAEPs) fell within normal developmental limits, and (2) late implanted children in whom CAEPs were outside of normal developmental limits. Miller's test of the race model inequality was performed for each group in order to examine the effects of auditory deprivation on multisensory integration abilities after implantation. RESULTS: Results revealed a significant violation of the race model inequality in the normally hearing and early implanted children, but not in the group of late implanted children. CONCLUSION: These results suggest that coactivation to multi-modal sensory input cannot explain the decreased reaction times to multi-modal input in late implanted children. These results are discussed in regards to current models for coactivation to redundant sensory information.