Effect of age, electrode array, and time on cochlear implant impedances

Velandia, Sandra; Martinez, Diane; Goncalves, Stefania; Peña, Stefanie; Bas, Esperanza; Ein, Liliana; Prentiss, Sandra; Telischi, Fred F.; Angeli, Simón I.; Dinh, Christine T.

doi:10.1080/14670100.2020.1788859

Cited by 7 publications

(10 citation statements)

References 32 publications

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“…Four-point impedance measurements are a relatively new marker in cochlear implantation which continue to be a focus for study (Bester et al 2020a). Results in animal and human studies have shown that impedance measurements can be used as a marker for fibrosis (Shepherd et al 1995; Duan et al 2004; Tykocinski et al 2005; O’Leary et al 2013; Wilk et al 2016; Chang et al 2017; Ishai et al 2017; Lo et al 2018; Shaul et al 2019; Briggs et al 2020; Velandia et al 2020). Compared to monopolar impedances, it is expected that the effect of the individual electrical tissue properties is minimized in four-point impedance measurements and thereby the local conductive environment between the electrodes can be assessed more accurately.…”

Section: Discussionmentioning

confidence: 99%

Electrocochleographic Patterns Predicting Increased Impedances and Hearing Loss after Cochlear Implantation

et al. 2022

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Objectives: Different patterns of electrocochleographic responses along the electrode array after insertion of the cochlear implant electrode array have been described. However, the implications of these patterns remain unclear. Therefore, the aim of the study was to correlate different peri- and postoperative electrocochleographic patterns with four-point impedance measurements and preservation of residual hearing. Design: Thirty-nine subjects with residual low-frequency hearing which were implanted with a slim-straight electrode array could prospectively be included. Intracochlear electrocochleographic recordings and four-point impedance measurements along the 22 electrodes of the array (EL, most apical EL22) were conducted immediately after complete insertion and 3 months after surgery. Hearing preservation was assessed after 3 months. Results: In perioperative electrocochleographic recordings, 22 subjects (56%) showed the largest amplitude around the tip of the electrode array (apical-peak, AP, EL20 or EL22), whereas 17 subjects (44%) exhibited a maximum amplitude in more basal regions (mid-peak, MP, EL18 or lower). At 3 months, in six subjects with an AP pattern perioperatively, the location of the largest electrocochleographic response had shifted basally (apical-to-mid-peak, AP-MP). Latency was analyzed along the electrode array when this could be discerned. This was the case in 68 peri- and postoperative recordings (87% of all recordings, n = 78). The latency increased with increasing insertion depth in AP recordings (n = 38, median of EL with maximum latency shift = EL21). In MP recordings (n = 30), the maximum latency shift was detectable more basally (median EL12, p < 0.001). Four-point impedance measurements were available at both time points in 90% (n = 35) of all subjects. At the 3-month time point, recordings revealed lower impedances in the AP group (n = 15, mean = 222 Ω, SD = 63) than in the MP (n = 14, mean = 295 Ω, SD= 7 6) and AP-MP groups (n = 6, mean = 234 Ω, SD = 129; AP versus MP p = 0.026, AP versus AP-MP p = 0.023, MP versus AP-MP p > 0.999). The amplitudes of perioperative AP recordings showed a correlation with preoperative hearing thresholds (r2=0.351, p = 0.004). No such correlation was detectable in MP recordings (r2 = 0.033, p = 0.484). Audiograms were available at both time points in 97% (n = 38) of all subjects. The mean postoperative hearing loss in the AP group was 13 dB (n = 16, SD = 9). A significantly larger hearing loss was detectable in the MP and AP-MP groups with 28 (n = 17, SD = 10) and 35 dB (n = 6, SD = 13), respectively (AP versus MP p = 0.002, AP versus AP-MP p = 0.002, MP versus AP-MP p = 0.926). Conclusion: MP and AP-MP response patterns of the electrocochleographic responses along the electrode array after cochlear implantation are correlated with higher four-point impedances and poorer postoperative hearing compared to AP response patterns. The higher impedances suggest that MP and AP-MP patterns are associated with increased intracochlear fibrosis.

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Section: Discussionmentioning

confidence: 99%

Electrocochleographic Patterns Predicting Increased Impedances and Hearing Loss after Cochlear Implantation

et al. 2022

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“…33 For example, perimodiolar and lateral wall electrodes may vary in distance from the modiolus. 17 In addition, the use of a dexamethasone-eluting Cochlear Contour Advance electrode has been shown to determine different impedance values than standard electrodes. 34,35 These data suggest that intracochlear inflammation is present, and it can be modulated and it may influence impedance levels.…”

Section: Discussionmentioning

confidence: 99%

“…In general, the pattern of impedance values for each electrode is expected to be similar for all the four testing configurations. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] See ►Fig. 1 for a schematic explanation of the different coupling modes.…”

Section: Impedance Values Measurementsmentioning

confidence: 99%

“…4 Very few studies are available in medical literature describing the trend of impedance values over time for the Cochlear Nucleus devices. 5,[13][14][15][16][17] All studies had the limitation to be conducted in heterogeneous populations in terms of hearing loss cause, including etiologies characterized by progressive ossification processes such as meningitis or otosclerosis. Consequently, it is still unknown if impedance trend may or may not be influenced by the cause of the hearing loss.…”

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confidence: 99%

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Long-Term Impedance Trend in Cochlear Implant Users with Genetically Determined Congenital Profound Hearing Loss

et al. 2022

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Background Impedance is a basic parameter registered at any cochlear implant (CI) fitting section. It is useful in monitoring electrode functioning and the status of the surrounding anatomical structures. Purpose The main aim of this study is to evaluate the 5-year impedance-value trend in patients affected by congenital genetically determined profound hearing loss implanted with Cochlear Nucleus devices. Research Design Observational, retrospective, monocentric study. Study Sample Twenty-seven consecutive patients (9 females: 12.0 ± 7.6 years old; range: 4.2–40.4) with genetic diagnosis of GJB2 mutation causing congenital profound hearing loss who underwent cochlear implantation from 2010 to 2020 with good auditory benefit. Intervention Impedance values of the CIs were obtained from the CIs' programming software that registers those parameters for each follow-up section of each patient. Data Collection and Analysis Impedance values were measured over time (activation, 6, 12, 24, and 60 months after cochlear implantation), for each of the 22 electrodes, in common ground, monopolar 1, monopolar 2, and monopolar 1 + 2 stimulation modes. Results A significant variation was found between CI activation and 6-month follow-up. This difference was found for each of the 22 electrodes. Electrodes 1 to 4 showed higher impedance values compared with all other electrodes in each time interval. Repeated-measures analysis of variance ruled out significant variations in impedance values from 6-month to 5-year follow-up. Conclusions Impedance values were extremely stable after activation, at least for the first 5 years. In these cases, even minimal impedance variations should be carefully evaluated for their possible implications on hearing performance.

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“…Increasingly advanced speech processing strategies that deliver signals to the auditory nerve through a greater number of active electrodes with a better dynamic range favor more successful hearing, language, and speech development [37][38][39]. Therefore, the success of CI technology is logically connected with expert performance management of these devices, that is, the programming of their processors according to the specific needs of individual users.…”

Section: Predictors Of Cochlear Implantation Outcome In the Pediatric...mentioning

confidence: 99%

Language Intervention Instead of Speech Intervention for Children With Cochlear Implants

Šantić¹,

Bonetti²

2023

J Audiol Otol

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Cochlear implants are a standard rehabilitation option for children with severe hearing loss or deafness, allowing access to speech sounds necessary for the development of spoken language. However, the speech-language outcomes of pediatric cochlear implant users vary widely and are not directly or exclusively linked to technology but to combinations of individual audiological, personal, technical, and habilitational factors. These combinations may not favor spoken language development, which may further be linked to the issue of prior insistence on spoken language learning and associated with a high risk of language deprivation. Here, we discuss the outcomes of cochlear implantation from a habilitative perspective and lay down the efforts and resources necessary for the development of communication competence after cochlear implantation rather than the achievement of specific hearing, language, or speech skills that have limited socioemotional and educational contributions and do not guarantee an independent or productive life.

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Effect of age, electrode array, and time on cochlear implant impedances

Cited by 7 publications

References 32 publications

Electrocochleographic Patterns Predicting Increased Impedances and Hearing Loss after Cochlear Implantation

Electrocochleographic Patterns Predicting Increased Impedances and Hearing Loss after Cochlear Implantation

Long-Term Impedance Trend in Cochlear Implant Users with Genetically Determined Congenital Profound Hearing Loss

Language Intervention Instead of Speech Intervention for Children With Cochlear Implants

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