A comparison of intra- versus post-operatively acquired electrically evoked compound action potentials

Wermeskerken, Gijs K. A. van; Olphen, Adriaan F. van; Zanten, G. A. Van

doi:10.1080/14992020600833189

Cited by 18 publications

(7 citation statements)

References 14 publications

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“…If ECAPs could be reliably evoked from a vestibular implant, the method would have two potential advantages relative to measuring EEMs. First, vestibular ECAP recordings could be made intraoperatively when the subject is sedated, because the excitatory mechanisms of peripheral nerve stimulation are typically not affected by general anesthesia [37, 38]. Second, the ECAP recordings could be made quickly, allowing repeated measures to be made while the electrode array placement is adjusted.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the Electrically Evoked Compound Action Potential of the Vestibular Nerve

Nie¹,

Bierer²,

Ling³

et al. 2011

Otology &Amp; Neurotology

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Objective We recorded intra-operative and post-operative electrically-evoked compound action potentials (ECAPs) in rhesus monkeys implanted with a vestibular neurostimulator. The objectives were to correlate the generation of slow-phase nystagmus or eye twitches induced by electrical stimulation of the implanted semicircular canal with the presence or absence of the vestibular ECAP responses, and to assess the effectiveness of ECAP monitoring during surgery to guide surgical insertion of electrode arrays into the canals. Design Four rhesus monkeys (a total of seven canals) were implanted with a vestibular neurostimulator modified from the Nucleus Freedom™ cochlear implant. ECAP recordings were obtained during surgery or at various intervals post-surgery using the Neural Response Telemetry™ feature of the clinical Custom Sound EP™ software. Eye movements during electrical stimulation of individual canals were recorded with a scleral search coil system in the same animals. Results Measurable vestibular ECAPs were observed intra-operatively or post-operatively in three implanted animals. Robust and sustained ECAPs were obtained in three monkeys at the test intervals of 0, 7, or >100 days post implantation surgery. In all three animals, stimulation with electrical pulse trains produced measurable eye movements in a direction consistent with the vestibulo-ocular reflex from the implanted semicircular canal. In contrast, electrically-evoked eye movements could not be measured in three of the seven implanted canals none of which produced distinct vestibular ECAPs. In two animals, ECAP waveforms were systematically monitored during surgery and the procedure proved crucial to the success of vestibular implantation. Conclusions Vestibular ECAPs exhibit similar morphology and growth characteristics to cochlear ECAPs from human cochlear implant patients. The ECAP measure is well correlated with the functional activation of eye movements by electrical stimulation post implantation surgery. The intra-operative ECAP recording technique is an efficient tool to guide the placement of electrode array into the semicircular canals.

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Section: Introductionmentioning

confidence: 99%

Characterization of the Electrically Evoked Compound Action Potential of the Vestibular Nerve

Nie¹,

Bierer²,

Ling³

et al. 2011

Otology &Amp; Neurotology

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“…In cochlear implants, which have been approved clinically since 1984, 3 built-in electronics and reverse telemetry have been developed to allow recording of auditory nerve responses to electric stimuli. These measures nowadays are used routinely to assess functionality of the implant intraoperatively, 4 and can be applied for rehabilitation purposes. 5 Measurement of electrically evoked responses in the visual system likewise may prove useful during surgery and rehabilitation.…”

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confidence: 99%

Electrically Elicited Visual Evoked Potentials in Argus II Retinal Implant Wearers

Stronks

Dagnelie

2013

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. We characterized electrically elicited visual evoked potentials (eVEPs) in Argus II retinal implant wearers.METHODS. eVEPs were recorded in four subjects, and analyzed by determining amplitude and latency of the first two positive peaks (P 1 and P 2 ). Subjects provided subjective feedback by rating the brightness and size of the phosphenes. We established eVEP input-output relationships, eVEP variability between and within subjects, the effect of stimulating different areas of the retina, and the maximal pulse rate to record eVEPs reliably.RESULTS. eVEP waveforms had low signal-to-noise ratios, requiring long recording times and substantial signal processing. Waveforms varied between subjects, but showed good reproducibility and consistent parameter dependence within subjects. P 2 amplitude overall was the most robust outcome measure and proved an accurate indicator of subjective threshold. Peak latencies showed small within-subject variability, yet their correlation with stimulus level and subjective rating were more variable than that of peak amplitudes. Pulse rates of up to 2 / 3 Hz resulted in reliable eVEP recordings. Perceived phosphene brightness declined over time, as reflected in P 1 amplitude, but not in P 2 amplitude or peak latencies. Stimulating-electrode location significantly affected P 1 and P 2 amplitude and latency, but not subjective percepts.CONCLUSIONS. While recording times and signal processing are more demanding than for standard visually evoked potential (VEP) recordings, the eVEP has proven to be a reliable tool to verify retinal implant functionality. eVEPs correlated with various stimulus parameters and with perceptual ratings. In view of these findings, eVEPs may become an important tool in functional investigations of retinal prostheses. (ClinicalTrials.gov number NCT00407602.) KEYWORDS: retinal implant, visual evoked potential, visual prosthesis, psychophysics DOEL. Karakterisering van elektrisch opgeroepen visueel opgewekte potentialen (eVEPs) in Argus II retina prothese gebruikers.METHODES. eVEP golfvormen werden in vier proefpersonen gemeten. De amplitude en latentie van de eerste twee positieve pieken (P 1 en P 2 ) werd gecorreleerd met stimulusnivo en subjectief percept. eVEP variabiliteit tussen en binnen subjecten werd bepaald, alswel de maximale pulsrepetitiesnelheid waarmee betrouwbaar eVEPs opgenomen konden worden. De proefpersonen gaven een indicatie van hun subjectieve percept door de helderheid en grootte van de fosfenen te schatten.RESULTATEN. eVEP golfvormen hadden een lage signaal-ruis verhouding, wat lange opnametijden en intensieve signaalbewerking nodig maakte. Golfvormen varieerden tussen proefpersonen, maar binnen proefpersonen waren ze goed reproduceerbaar. Pieklatenties hadden een lage variabiliteit binnen een proefpersoon, maar desondanks waren de correlaties met stimulusnivo en subjectief percept ondergeschikt aan die van piekamplitude. P 2 amplitude was de meest betrouwbare uitkomstmaat en een goede schatter van de perceptieve drempel. Pulsrepeti...

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“…Subsequently, this allows achieving an optimum dynamic range. This is a very important step for proper hearing and the successful use of cochlear implants [5, 6]. It is important to evaluate the effect of anesthesia on the intraoperatively acquired e-ECAP measurements.…”

Section: Discussionmentioning

confidence: 99%

“…When done intraoperatively, the child is still under general anesthesia. This allows the audiologist to apply high stimulation levels which result in a high success rate of recording accurate e-ECAP responses [6].…”

Section: Introductionmentioning

confidence: 99%

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

Alhowary

Aleshawi

Alali

et al. 2019

Anesthesiology Research and Practice

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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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A comparison of intra- versus post-operatively acquired electrically evoked compound action potentials

Cited by 18 publications

References 14 publications

Characterization of the Electrically Evoked Compound Action Potential of the Vestibular Nerve

Characterization of the Electrically Evoked Compound Action Potential of the Vestibular Nerve

Electrically Elicited Visual Evoked Potentials in Argus II Retinal Implant Wearers

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

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