人工耳蜗使用者中不一致结局的筛查：基于ECAP振幅的分类

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中文摘要

背景： 人工耳蜗（CI）植入者在术后言语识别结局方面表现出相当大的变异性。虽然电诱发复合动作电位（ECAP）记录在现代CI系统中常规可用，但其作为潜在结局指标在常规临床实践中的实用性尚未被系统确立。
目的： 本研究考察常规测量的ECAP特征，即振幅（A-ECAP）和阈值（T-ECAP），与CI使用者术后词语识别得分之间的关系，并推导一种临床可行的基于ECAP的筛查方法。词语识别良好和不良分别定义为WRS65(CI)高于和等于或低于30%的基准。
方法： 分析了两个独立临床数据集的数据。筛查程序使用Clinic 1的数据（术后200 cL的ECAP记录）开发，并使用Clinic 2的数据（术中230 cL的记录）验证。应用一种基于各数据集内经验性推导的ECAP阈值与振幅之间回归关系的转换程序，将Clinic 2中在230 cL获得的ECAP振幅转换为200 cL的等效值，从而实现跨中心可比性。使用受试者工作特征（ROC）分析推导针对30%词语识别基准的关键A-ECAP截断值。
结果： 在两个数据集中，高A-ECAP始终与高词语识别相关，而T-ECAP未显示可比的一致性。在固定刺激水平200 cL下，关键ECAP振幅121 µV在推导数据集中产生100%的特异性。在验证数据集中，阳性预测值为94%，165名植入者中有5名显示不一致结局，定义为振幅高于标准合并词语识别不良。
结论： 记录ECAP的工具在临床常规中已充分建立，但人们很少关注这些反应所携带的关于言语识别的信息。大ECAP振幅始终与良好词语识别相关，而ECAP阈值则不然。ECAP振幅不能预测个体结局。其价值在于识别不一致病例——大振幅合并词语识别不良——在这些病例中结局不能归因于外周反应，需要进一步评估，首先从调机开始。这些植入者是否能从再次干预中获益需要前瞻性评估。

英文摘要

BACKGROUND: Cochlear implant (CI) recipients show considerable variability in postoperative speech recognition outcomes. While electrically evoked compound action potential (ECAP) recordings are routinely available in modern CI systems, their usefulness in routine clinical practice as a potential outcome measure has not been systematically established.
OBJECTIVES: This study examined the relationship between routinely measured ECAP characteristics as amplitude (A-ECAP) and threshold (T-ECAP) and postoperative word recognition scores in CI users and derived a clinically feasible ECAP-based screening method. Good and poor word recognition were defined as WRS65(CI) above and at or below a benchmark of 30%, respectively.
METHODS: Data from two independent clinical datasets were analyzed. The screening procedure was developed using data from Clinic 1 (postoperative ECAP recordings at 200 cL) and validated using data from Clinic 2 (intraoperative recordings at 230 cL). A transformation procedure, based on the regression between ECAP threshold and amplitude empirically derived within each dataset, was applied to convert ECAP amplitudes obtained at 230 cL in Clinic 2 into equivalent values at 200 cL, thereby enabling cross-centre comparability. Receiver operating characteristic (ROC) analysis was used to derive a critical A-ECAP cut-off value targeting a word recognition benchmark of 30%.
RESULTS: High A-ECAP consistently associated with high word recognition across both datasets, whereas T-ECAP showed no comparable consistency. A critical ECAP amplitude of 121 µV (at a fixed stimulation level of 200 cL) yielded 100% specificity in the derivation dataset. In the validation dataset the positive predictive value was 94%, with five of 165 recipients showing a discordant outcome, defined as an amplitude above the criterion combined with poor word recognition CONCLUSIONS: Tools for recording ECAP are well established in clinical routine, but little attention is given to the information these responses carry regarding speech recognition. A large ECAP amplitude was consistently associated with good word recognition, whereas ECAP threshold was not. ECAP amplitude does not predict individual outcome. Its value lies in identifying discordant cases - a large amplitude combined with poor word recognition - in which the outcome cannot be attributed to the peripheral response and further evaluation, beginning with the fitting, is indicated. Whether these recipients benefit from re-intervention requires prospective evaluation.