Importance of Perimodiolar Electrode Position for Psychoacoustic Discrimination in Cochlear Implantation

Macías, Ángel Ramos; Zaballos, María Teresa Pérez; Miguel, Ángel Ramos de; Paz, Javier Cervera

doi:10.1097/mao.0000000000001594

Cited by 8 publications

(11 citation statements)

References 32 publications

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“…As previous publications show [23,30], the electrode distance influences electrode discrimination. In this research, we also provide more empirical evidence in support of the hypothesis that the electrode distance to the inner wall of the cochlea is a significant variable for the prediction of electrode discrimination ability.…”

Section: Discussionmentioning

confidence: 69%

“…That has a big impact on the patient hearing workload, and higher workload means fatigue at the end of the day. Several studies have demonstrated that removing poorly discriminated electrodes from a subject's processor map resulted in improved speech recognition scores in some subjects [23].…”

Section: Discussionmentioning

confidence: 99%

“…This method has been previously described [23]. An alternative forced choice experiment using variable electrodes (e11, e12, e13, e14, e15), where the patient must guess which one of the three sounds is different, using two from variable electrode and one fixed electrode.…”

Section: Pitch Discrimination Methodsmentioning

confidence: 99%

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Analysis of Neural Interface When Using Modiolar Electrode Stimulation. Radiological Evaluation, Trans-Impedance Matrix Analysis and Effect on Listening Effort in Cochlear Implantation

Ramos‐de‐Miguel

Falcón-González

Ramos‐Macías

2021

JCM

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Background: The proximity of the electrode to the modiolar wall may be of interest to investigate the effect of pitch discrimination. This research establishes the relation between these factors and whether perimodiolar positions may provide benefits regarding improved electrode discrimination. Methods: A prospective randomized study including 24 post-lingual deaf adults was performed. A psychoacoustic study was done by using a psychoacoustic research platform. Radiological study, and a cone-beam computed tomography was used to assess post cochlear implantation electrodes’ position. Trans-impedance matrix (TIM) analysis was performed after cochlear implant insertion in all cases, and pupillometry test was also performed. Results: 12 patients received a slim perimodiolar electrode array, and 12 patients received a straight electrode array. Although all the patients showed similar speech test results after 12 months follow-up, those implanted with a perimodiolar electrode obtained better scores in electrode discrimination test and pupillometry test, and showed more homogenous TIM patterns. Conclusions: The better positioning of the electrode array seams to provide a better hearing resolution and less listening effort trans-impedance matrix seems to be a useful tool to analyze positioning of the perimodiolar array.

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Section: Discussionmentioning

confidence: 69%

Section: Discussionmentioning

confidence: 99%

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Analysis of Neural Interface When Using Modiolar Electrode Stimulation. Radiological Evaluation, Trans-Impedance Matrix Analysis and Effect on Listening Effort in Cochlear Implantation

Ramos‐de‐Miguel

Falcón-González

Ramos‐Macías

2021

JCM

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“…Previous studies have shown that impedances were lower the closer the electrode array was to the modiolus, albeit with a monopolar configuration and not four-point (19–21). High basal impedances have been previously reported for perimodiolar implants; however, the cause was not identified by Tykocinski et al (7), who excluded modiolar proximity as a primary cause.…”

Section: Discussionmentioning

confidence: 99%

“…This effect is more prominent in lateral wall implants than perimodiolar implants and may be a result of electrode positioning. CI532 devices are designed to closely hug the medial wall, with the electrode contacts facing the medial wall to be closer to the modiolus and provide better neural stimulation and pitch discrimination (19). Because the electrode contacts are in close proximity to the medial wall, the spread of the applied current is directed into bone, reducing the influence of the cross-sectional area of the scala on 4PIs.…”

Section: Discussionmentioning

confidence: 99%

Four-Point Impedance Changes After Cochlear Implantation for Lateral Wall and Perimodiolar Implants

et al. 2022

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Objective: Monitor four-point impedance in cochlear implant recipients over time and determine if implant type, surgical approach, and electrode positioning affected impedance measurements. Study Design: Prospective observational. Setting: Hospital. Patients: Adult cochlear implant recipients implanted with a perimodiolar or lateral wall cochlear implant. Main Outcome Measure(s): Mean values for four-point impedances were calculated for all electrode contacts at perioperative and 3 months after surgery. Linear mixed models were applied to the impedance data to compare between implant types and time points. The angular insertion depth and electrode position relative to the medial and lateral wall, commonly termed the Intracochlear Position Index (ICPI), were collected and compared with impedance measurements. Results: Perioperatively, the four-point impedance was similar between implant types, with perimodiolar implants having marginally higher impedance values in the basal region. At 3 months after surgery, impedances significantly increased in the basal half of the electrode array for both implants, with higher impedance values for CI532 implants. There were no significant differences in insertion angle depth between implant types. The ICPI values for the seven most basal electrodes were similar for both implants; however, CI532 arrays were significantly more medially placed along the remaining apical portion of the array, which is expected. ICPI values did not correlate with impedance measurements for either implant. Conclusions: Four-point impedance increases at 3 months after surgery may reflect fibrous tissue formation after cochlear implantation. The higher impedance values in perimodiolar implants may reflect a more extensive fibrosis formation as a result of surgical approaches used, requiring drilling of the cochlea bone.

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Vergleich des Sprachverstehens unter Berücksichtigung der genauen Elektrodenposition (SRA/MRA/CA)

Roßberg

Timm

Roßberg

et al. 2023

Laryngorhinootologie

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ZusammenfassungDie Cochlea-Implantation ist ein seit Jahren routinemäßig durchgeführtes Verfahren zur Hörrehabilitation. Trotzdem sind noch nicht alle Parameter bekannt, welche das Sprachverstehen nach der Implantation beeinflussen. Wir prüfen die Hypothese, ob ein Zusammenhang zwischen dem Sprachverstehen und der Position verschiedener Elektrodentypen im Bezug zum Modiolus in der Cochlea bei identischem Sprachprozessor besteht. Hierfür stellen wir in dieser retrospektiven Studie die Hörergebnisse mit unterschiedlichen Elektrodentypen („Straight Research Array“ (SRA), „Modiolar Research Array“ (MRA) und „Contour Advance“ (CA)) des Herstellers Cochlear in matched pair groups gegenüber.Nach Erstellung von 3 Gruppen durch „matched pairs“ (n=52 Patienten pro Gruppe) erfolgte die Ausmessung der cochleären Parameter (Länge der Außenwand, Einführungswinkel, Insertionstiefe, cochleäre Coverage und Gesamtlänge der Elektrode in der Cochlea, Wrapping Factor) in der routinemäßig durchgeführten prä- und postoperativen hochauflösenden CT oder DVT. Als Zielvariable wurde das Freiburger Einsilberverstehen ein Jahr nach der Implantation verwendet.Im Freiburger Einsilbertest ein Jahr postoperativ kamen die Patienten mit MRA auf 51,2%, die Patienten mit SRA auf 49,5% und die Patienten mit CA auf 58,0% Einsilberverstehen. Es konnte gezeigt werden, dass bei steigender cochleärer Coverage bei der MRA und CA das Sprachverstehen der Patienten sinkt und es bei der SRA steigt. Zusätzlich konnte gezeigt werden, dass bei steigendem „Wrapping Factor“ das Einsilberverstehen steigt.Die Ergebnisse zeigen, dass die Lage der Elektrode zum Modiolus nicht der einzige Faktor ist, der Unterschiede im Outcome nach Cochlear-Implantation erklärt.

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Importance of Perimodiolar Electrode Position for Psychoacoustic Discrimination in Cochlear Implantation

Abstract: Perimodiolar electrodes could be a better solution in terms of pitch discrimination both because they are closer to the modiolus and because their impedance is lower.

Cited by 8 publications

References 32 publications

Analysis of Neural Interface When Using Modiolar Electrode Stimulation. Radiological Evaluation, Trans-Impedance Matrix Analysis and Effect on Listening Effort in Cochlear Implantation

Analysis of Neural Interface When Using Modiolar Electrode Stimulation. Radiological Evaluation, Trans-Impedance Matrix Analysis and Effect on Listening Effort in Cochlear Implantation

Four-Point Impedance Changes After Cochlear Implantation for Lateral Wall and Perimodiolar Implants

Vergleich des Sprachverstehens unter Berücksichtigung der genauen Elektrodenposition (SRA/MRA/CA)

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