scholarly journals Functional Outcomes of Cochlear Implantation in Children with Bilateral Cochlear Nerve Aplasia

2021 ◽  
Author(s):  
Goun Choe ◽  
Young Seok Kim ◽  
Myung-Whan Suh ◽  
Moo Kyun Park ◽  
Seung-Ha Oh ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Functional Outcomes ◽  
Dynamic Range ◽  
Early Stage ◽  
Compound Action Potential ◽  
Auditory Brainstem ◽  
Cochlear Nerve ◽  
Cross Sectional ◽  
Evoked Compound Action Potential ◽  
Auditory Performance

Abstract Many otologists face a dilemma in the decision-making process of surgical management of patients with cochlear nerve (CN) aplasia. Currently, evidence on cochlear implantation (CI) outcomes in patients with CN aplasia is limited. We scrutinized functional outcomes in 37 ears of 21 children with bilateral CN aplasia who underwent unilateral or bilateral CI based on cross-sectional and longitudinal assessments. The Categories of Auditory Performance (CAP) scores gradually improved throughout the 3-year follow-up; however, variable outcomes existed between individuals. Specifically, the majority of recipients with a 1-year postoperative CAP score ≤1 remained steady or achieved awareness of environmental sounds, while recipients with early stage hearing benefit had markedly improved auditory performance and could possibly discriminate some speech without lipreading. Meanwhile, intraoperative electrically evoked compound action potential was not correlated with postoperative CAP score. The dynamic range between T and C levels remained unchanged. Our results further refine those of previous studies on the clinical feasibility of CI as the first treatment modality to elicit favorable auditory performance in children with CN aplasia. However, special attention should be paid to pediatric patients with an early postoperative CAP score ≤1 for identification of unsuccessful cochlear implants and switching to auditory brainstem implants.

Auditory processing of complex sounds: an overview

1992 ◽  
Vol 336 (1278) ◽  
pp. 295-306 ◽  
Keyword(s):  
Auditory System ◽  
Auditory Processing ◽  
Dynamic Range ◽  
Auditory Brainstem ◽  
Frequency Selectivity ◽  
Dorsal Cochlear Nucleus ◽  
Cochlear Nerve ◽  
Complex Sounds ◽  
Wide Range ◽  
Time Coding

The past 30 years has seen a remarkable development in our understanding of how the auditory system - particularly the peripheral system - processes complex sounds. Perhaps the most significant has been our understanding of the mechanisms underlying auditory frequency selectivity and their importance for normal and impaired auditory processing. Physiologically vulnerable cochlear filtering can account for many aspects of our normal and impaired psychophysical frequency selectivity with important consequences for the perception of complex sounds. For normal hearing, remarkable mechanisms in the organ of Corti, involving enhancement of mechanical tuning (in mammals probably by feedback of electro-mechanically generated energy from the hair cells), produce exquisite tuning, reflected in the tuning properties of cochlear nerve fibres. Recent comparisons of physiological (cochlear nerve) and psychophysical frequency selectivity in the same species indicate that the ear’s overall frequency selectivity can be accounted for by this cochlear filtering, at least in band width terms. Because this cochlear filtering is physiologically vulnerable, it deteriorates in deleterious conditions of the cochlea - hypoxia, disease, drugs, noise overexposure, mechanical disturbance - and is reflected in impaired psychophysical frequency selectivity. This is a fundamental feature of sensorineural hearing loss of cochlear origin, and is of diagnostic value. This cochlear filtering, particularly as reflected in the temporal patterns of cochlear fibres to complex sounds, is remarkably robust over a wide range of stimulus levels. Furthermore, cochlear filtering properties are a prime determinant of the ‘place’ and ‘time’ coding of frequency at the cochlear nerve level, both of which appear to be involved in pitch perception. The problem of how the place and time coding of complex sounds is effected over the ear’s remarkably wide dynamic range is briefly addressed. In the auditory brainstem, particularly the dorsal cochlear nucleus, are inhibitory mechanisms responsible for enhancing the spectral and temporal contrasts in complex sounds. These mechanisms are now being dissected neuropharmacologically. At the cortical level, mechanisms are evident that are capable of abstracting biologically relevant features of complex sounds. Fundamental studies of how the auditory system encodes and processes complex sounds are vital to promising recent applications in the diagnosis and rehabilitation of the hearing impaired.

scholarly journals Comparison of Electrically Evoked Compound Action Potential Thresholds and Loudness Estimates for the Stimuli Used to Program the Advanced Bionics Cochlear Implant

2010 ◽  
Vol 21 (01) ◽  
pp. 016-027 ◽  
Author(s):  
Eun Kyung Jeon ◽  
Carolyn J. Brown ◽  
Christine P. Etler ◽  
Sara O'Brien ◽  
Li-Kuei Chiou ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Dynamic Range ◽  
Compound Action Potential ◽  
Behavioral Measures ◽  
Speech Processor ◽  
Compound Action Potentials ◽  
Evoked Compound Action Potential ◽  
The Individual ◽  
The Relationship ◽  
Compound Action

Background: In the mid-1990s, Cochlear Corporation introduced a cochlear implant (CI) to the market that was equipped with hardware that made it possible to record electrically evoked compound action potentials (ECAPs) from CI users of all ages. Over the course of the next decade, many studies were published that compared ECAP thresholds with levels used to program the speech processor of the Nucleus CI. In 2001 Advanced Bionics Corporation introduced the Clarion CII cochlear implant (the Clarion CII internal device is also known as the CII Bionic Ear). This cochlear implant was also equipped with a system that allowed measurement of the ECAP. While a great deal is known about how ECAP thresholds compare with the levels used to program the speech processor of the Nucleus CI, relatively few studies have reported comparisons between ECAP thresholds and the levels used to program the speech processor of the Advanced Bionics CI. Purpose: To explore the relationship between ECAP thresholds and behavioral measures of perceptual dynamic range for the range of stimuli commonly used to program the speech processor of the Advanced Bionics CI. Research Design: This prospective and experimental study uses correlational and descriptive statistics to define the relationship between ECAP thresholds and perceptual dynamic range measures. Study Sample: Twelve postlingually deafened adults participated in this study. All were experienced users of the Advanced Bionics CI system. Data Collection and Analysis: ECAP thresholds were recorded using the commercially available SoundWave software. Perceptual measures of threshold (T-level), most comfortable level (M-level), and maximum comfortable level (C-level) were obtained using both “tone bursts” and “speech bursts.” The relationship between these perceptual and electrophysiological variables was defined using paired t-tests as well as correlation and linear regression. Results: ECAP thresholds were significantly correlated with the perceptual dynamic range measures studied; however, correlations were not strong. Analysis of the individual data revealed considerable discrepancy between the contour of ECAP threshold versus electrode function and the behavioral loudness estimates used for programming. Conclusion: ECAP thresholds recorded from Advanced Bionics cochlear implant users always indicated levels where the programming stimulus was audible for the listener. However, the correlation between ECAP thresholds and M-levels (the primary metric used to program the speech processor of the Advanced Bionics CI), while statistically significant, was quite modest. If programming levels are to be determined on the basis of ECAP thresholds, care should be taken to ensure that stimulation is not uncomfortably loud, particularly on the basal electrodes in the array.

Cochlear implantation in children with labyrinthine anomalies and cochlear nerve deficiency: Implications for auditory brainstem implantation

2011 ◽  
Vol 121 (9) ◽  
pp. 1979-1988 ◽  
Author(s):  
Craig A. Buchman ◽  
Holly F. B. Teagle ◽  
Patricia A. Roush ◽  
Lisa R. Park ◽  
Debora Hatch ◽  
...  
Keyword(s):  
Cochlear Implantation ◽  
Auditory Brainstem ◽  
Cochlear Nerve ◽  
Cochlear Nerve Deficiency

scholarly journals Impedance and Electrically Evoked Compound Action Potential (ECAP) Drop within 24 Hours after Cochlear Implantation

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e71929 ◽  
Author(s):  
Joshua Kuang-Chao Chen ◽  
Ann Yi-Chiun Chuang ◽  
Georg Mathias Sprinzl ◽  
Tao-Hsin Tung ◽  
Lieber Po-Hung Li
Keyword(s):  
Action Potential ◽  
Cochlear Implantation ◽  
Compound Action Potential ◽  
Evoked Compound Action Potential ◽  
Compound Action

scholarly journals Measurements of the local evoked potential from the cochlear nucleus in patients with an auditory brainstem implant and its implication to auditory perception and audio processor programming

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249535
Author(s):  
Lutz Gärtner ◽  
Thomas Lenarz ◽  
Andreas Büchner
Keyword(s):  
Cochlear Nucleus ◽  
Auditory Perception ◽  
False Positive Rate ◽  
Electrode Array ◽  
Compound Action Potential ◽  
Auditory Brainstem ◽  
Auditory Brainstem Implant ◽  
Evoked Compound Action Potential ◽  
Positive Rate ◽  
Fitting In

The measurement of the electrically evoked compound action potential (ECAP) in cochlear implant (CI) patients is widely used to provide evidence of a functioning electrode-nerve interface, to confirm proper location of the electrode array and to program the sound processor. In patients with an auditory brainstem implant (ABI), a likewise versatile measurement would be desirable. The ECAP measurement paradigm “Alternating Polarity” was utilized to record responses via the implanted ABI electrode array placed on the cochlear nucleus. Emphasizing on the different location of stimulation and recording, these responses are called local evoked potentials (LEP). LEP measurements were conducted during the clinical routine in 16 ABI patients (12 children and 4 adults), corresponding to 191 electrode contacts. A retrospective analysis of these data revealed, that LEP responses were observed in 64.9% of all measured electrode contacts. LEP responses predicted auditory perception with a sensitivity of 90.5%. False-positive rate was 33.7%. Objective LEP thresholds were highly significantly (p < 0.001) correlated both to behavioral thresholds (Pearson’s r = 0.697) and behavioral most comfortable levels (r = 0.840). Therefore, LEP measurements have the potential to support fitting in ABI patients.

Effect of depth of general anesthesia on the threshold of electrically evoked compound action potential in cochlear implantation

2014 ◽  
Vol 272 (10) ◽  
pp. 2697-2701 ◽  
Author(s):  
Ali Eftekharian ◽  
Maryam Amizadeh ◽  
Kamran Mottaghi ◽  
Farhad Safari ◽  
Mozhgan Hosseinerezai Mahani ◽  
...  
Keyword(s):  
Action Potential ◽  
General Anesthesia ◽  
Cochlear Implantation ◽  
Compound Action Potential ◽  
Evoked Compound Action Potential ◽  
Compound Action

scholarly journals Effect of Depth of Total Intravenous General Anesthesia on Intraoperative Electrically Evoked Compound Action Potentials in Cochlear Implantation Surgery

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Ala”a Alhowary ◽  
Abdelwahab Aleshawi ◽  
Obada Alali ◽  
Manal Kassab ◽  
Diab Bani Hani ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Action Potentials ◽  
Compound Action Potential ◽  
Cochlear Implant Surgery ◽  
Compound Action Potentials ◽  
Evoked Compound Action Potential ◽  
Electrode Lead ◽  
Intravenous General Anesthesia ◽  
Compound Action

Purpose. This study aims to compare the effect of the depth of total intravenous anesthesia (TIVA) on intraoperative electrically evoked compound action potential (e-ECAP) thresholds in cochlear implant operations. Methods. Prospectively, a total of 39 patients aged between 1 and 48 years who were scheduled to undergo cochlear implantation surgeries were enrolled in this study. Every patient received both light and deep TIVA during the cochlear implant surgery. The e-ECAP thresholds were obtained during the light and deep TIVA. Results. After comparing the e-ECAP means for each electrode (lead) between the light and deep anesthesia, no significant differences were detected between the light and deep anesthesia. Conclusion. The depth of TIVA may have no significant influence on the e-ECAP thresholds as there was no statistical difference between the light and deep anesthesia.

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