Department of Otolaryngology, Head and Neck Surgery, Virgen Macarena University Hospital, Seville, Spain.
Biomedical Engineering Group, University of Seville, Seville, Spain.
Int J Audiol. 2023 Jul;62(7):650-658. doi: 10.1080/14992027.2022.2062578. Epub 2022 Apr 28.
To investigate electrically evoked auditory cortical responses (eACR) elicited from the stimulation of intracochlear electrodes based on individually fitted stimulation parameters in cochlear implant (CI) users.
An eACR setup based on individual fitting parameters is proposed. A 50-ms alternating biphasic pulse train was used to stimulate apical, medial, and basal electrodes and to evoke auditory cortical potentials (N1-P2 complex).
The eACR setup proposed was validated with 14 adult CI users.
Individual and grand-average eACR waveforms were obtained. The eACR amplitudes were lower in the basal than in the apical and medial regions. Earlier N1 latencies were found in CI users with lower maximum comfortable loudness levels and shorter phase duration in response to apical stimulation, while medial and basal stimulation resulted in earlier N1 latencies and larger N1-P2 amplitudes in users with longer CI experience.
eACR could be elicited by direct intracochlear stimulation using individual fitting parameters with a success rate of 71%. The highest cortical peak-to-peak amplitudes were obtained in response to apical stimulation. Unlike the P2, the N1 component appeared to be a consistent cortical potential to determine eACR and gain knowledge of the auditory processing beyond the cochlea in CI users. HighlightseACR can be elicited through direct stimulation of intracochlear electrodes.Stimulation of apical and medial regions yielded the highest N1-P2 amplitudes.CI users with lower maximum comfortable loudness levels had shorter N1 latencies during apical stimulation.The present dataset of mainly well-performing CI users suggests better cortical processing, that is, higher amplitudes and shorter latencies of N1.The N1 potential appears a more consistent and reliable potential than the P2 to determine eACR responses in CI users.
研究基于个体化刺激参数，对人工耳蜗植入（CI）患者的耳蜗内电极刺激，所引发的电诱发听觉皮质反应（eACR）。
提出了一种基于个体化适配参数的 eACR 检测方法。采用 50ms 交替双相脉冲串刺激顶、中、底电极，诱发听觉皮质电位（N1-P2 复合波）。
该 eACR 检测方法在 14 名成年 CI 用户中进行了验证。
获得了个体和总体平均 eACR 波形。eACR 振幅在基底电极处较顶、中电极处更低。在最大舒适级响度较低和对顶电极刺激的相位持续时间较短的 CI 用户中，N1 潜伏期更早；而在 CI 经验较长的用户中，对中、底电极刺激的 N1 潜伏期更早，N1-P2 振幅更大。
利用个体化适配参数，可通过直接耳蜗内刺激，获得成功率为 71%的 eACR。对顶电极刺激时，可获得最大皮质峰峰值振幅。与 P2 不同，N1 成分似乎是一种一致的皮质电位，可用于确定 eACR，并了解 CI 用户耳蜗外的听觉处理信息。
可通过直接刺激耳蜗内电极引发 eACR。
刺激顶、中电极可产生最大的 N1-P2 振幅。
顶电极刺激时，最大舒适级响度较低的 CI 用户的 N1 潜伏期更短。
本数据集主要来自表现良好的 CI 用户，提示更好的皮质处理，即更高的振幅和更短的潜伏期。
与 P2 相比，N1 电位似乎是一种更一致和可靠的潜在电位，可用于确定 CI 用户的 eACR 反应。
