House Clinic

Electrically evoked compound action potential (ECAP) can be used to measure the auditory nerve's response to electrical stimulation in cochlear implant (CI) users. In the Nurotron CI system, extracting the ECAP waveform from the stimulus artifact is time-consuming. We developed a new paradigm ("FastCAP") for use with Nurotron CI devices. In electrically evoked compound action potential in fast mode (FastCAP), N recordings are averaged directly on the CI hardware before data transmission, significantly reducing data transmission time. FastCAPs and ECAPs were measured across five electrodes and four stimulation levels per electrode. The FastCAP stimulation rate (33.3 Hz) is also faster than the ECAP rate (2.5 Hz). Results showed strong correlations between ECAPs and FastCAPs for N1 latency (r = 0.84, p < 0.001) and N1 amplitude (r = 0.97, p < 0.001). Test-retest reliability for FastCAPs was also high, with intraclass correlation coefficients of r = 0.87 for N1 latency (p < 0.001) and r = 0.96 for N1 amplitude (p < 0.001). The mean test time was 46.9 ± 1.4 s for the FastCAP and 340.3 ± 6.3 s for the ECAP. The FastCAP measurement time was significantly shorter than the ECAP measurement time (W = -210.0, p < 0.001). FastCAP thresholds were significantly correlated with behavioral thresholds in 7/20 participants and with comfortable loudness levels in 11/20 participants. The time required to measure FastCAPs was significantly lower than that for ECAPs. The FastCAP paradigm maintained the accuracy and reliability the ECAP measurements while offering a significant reduction in time requirements. This preliminary evaluation suggests that the FastCAP could be an effective clinical tool to optimize CI processor settings (e.g., threshold stimulation levels) in users of the Nurotron CI device.

The aim of this study was to replicate previous English-language musician advantage studies in Mandarin-speaking musicians and nonmusicians. Segregation of competing speech, melodic pitch perception, and spectro-temporal pattern perception were measured in normal-hearing native Mandarin-speaking musicians and nonmusicians. Speech recognition thresholds were measured in the presence of two-talker masker speech. The masker sex was either the same as or different from the target; target and masker speech were either co-located or spatially separated. Melodic pitch perception was tested using a melodic contour identification task. Spectro-temporal resolution was measured using a modified spectral ripple detection task. We hypothesized that, given musician advantages in pitch perception, musician effects would be larger when the target and masker sex was the same than when different. For all tests, performance was significantly better for musicians than for nonmusicians. Contrary to our expectation, larger musician effects were observed for segregation of competing speech when the target and masker sex was different. The results show that musician effects observed for non-tonal language speakers extend to tonal language speakers. The data also suggest that musician effects may depend on the difficulty of the listening task and may be reduced when listening tasks are too easy or too difficult.

Self-reported listening-related fatigue in adolescents with hearing loss (HL) was investigated. Specifically, the extent to which listening-related fatigue is associated with school accommodations, audiologic characteristics, and listening breaks was examined. Participants were 144 adolescents with HL ages 12-19 years. Data were collected online via Qualtrics. The Vanderbilt Fatigue Scale-Child was used to measure listening-related fatigue. Participants also reported on their use of listening breaks and school accommodations, including an Individualized Education Program (IEP) or 504 plan, remote microphone systems, closed captioning, preferential seating, sign language interpreters, live transcriptions, and notetakers. After controlling for age, HL laterality, and self-perceived listening difficulty, adolescents with an IEP or a 504 plan reported lower listening-related fatigue compared to adolescents without an IEP or a 504 plan. Adolescents who more frequently used remote microphone systems or notetakers reported higher listening-related fatigue compared to adolescents who used these accommodations less frequently, whereas increased use of a sign language interpreter was associated with decreased listening-related fatigue. Among adolescents with unilateral HL, higher age was associated with lower listening-related fatigue; no effect of age was found among adolescents with bilateral HL. Listening-related fatigue did not differ based on hearing device configuration. Adolescents with HL should be considered at risk for listening-related fatigue regardless of the type of hearing devices used or the degree of HL. The individualized support provided by an IEP or 504 plan may help alleviate listening-related fatigue, especially by empowering adolescents with HL to be self-advocates in terms of their listening needs and accommodations in school. Additional research is needed to better understand the role of specific school accommodations and listening breaks in addressing listening-related fatigue.

To investigate the role and distribution of various molecular markers using immunohistochemistry and immunofluorescence to further elucidate and understand the pathogenesis of otosclerosis. Archival celloidin formalin-fixed 20-micron thick histologic sections from 7 patients diagnosed with otosclerosis were studied and compared to controls. Sections in the mid-modiolar region were immunoreacted with rabbit polyclonal antibodies against nidogen-1, β2-laminin, collagen-IX, BSP, and monoclonal antibodies against TGF β-1 and ubiquitin. Digital images were acquired using a high-resolution light and laser confocal microscope. Nidogen-1, BSP, and collagen-IX were expressed in the otospongiotic regions, and to lesser extent, in the otosclerotic regions, the latter previously believed to be inactive. β2-laminin and ubiquitin were uniformly expressed in both otospongiotic and otosclerotic regions. There was a basal level of expression of all of these markers in the normal hearing and sensorineural hearing loss specimens utilized as control. TGF β -1, however, though present in the otosclerosis bones, was absent in the normal hearing and sensorineural hearing loss controls. Our results propose that the activity and function of TGF-1 may play a key role in the development and pathogenesis of otosclerosis. Further studies utilizing a higher number of temporal bone specimens will be helpful for future analysis and to help decipher its role as a potential target in therapeutic interventions.

(1) Background: Incomplete excision of vestibular schwannomas (VSs) is sometimes preferable for facial nerve preservation. On the other hand, subtotal resection may be associated with higher tumor recurrence. We evaluated the correlation between intra-operative assessment of residual tumor and early and follow-up imaging. (2) Methods: The charts of all patients undergoing primary surgery for sporadic vestibular schwannoma during the study period were retrospectively reviewed. Data regarding surgeons' assessments of the extent of resection, and the residual size of the tumor on post-operative day (POD) one and follow-up MRI were extracted. (3) Results: Of 109 vestibular schwannomas meeting inclusion criteria, gross-total resection (GTR) was achieved in eighty-four, near-total (NTR) and sub-total resection (STR) in twenty-two and three patients, respectively. On follow up imaging, volumetric analysis revealed that of twenty-two NTRs, eight were radiographic GTR and nine were radiographic STR (mean volume ratio 11.9%), while five remained NTR (mean volume ratio 1.8%). Of the three STRs, two were radiographic GTR while one remained STR. Therefore, of eighteen patients with available later follow up MRIs, radiographic classification of the degree of resection changed in six. (4) Conclusions: An early MRI (POD#1) establishes a baseline for the residual tumor that may be more accurate than the surgeon's intraoperative assessment and may provide a beneficial point of comparison for long-term surveillance.