Pijl Sipke, Westerberg Brian D, Gustin Cindy, Fong Lisa
School of Audiology and Speech Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
J Am Acad Audiol. 2008 May;19(5):435-42. doi: 10.3766/jaaa.19.5.6.
Proper intracochlear placement of cochlear implant electrode arrays is believed to be important for optimum speech perception results. However, objective tests of cochlear implant function typically provide little or no information about the intracochlear placement of the array. We report the results for a variety of objective tests, including averaged electrode voltage (AEV) measurements, in a patient where the electrode array had folded up on itself during insertion.
To determine whether any of the objective measures provided evidence of incorrect electrode placement.
Objective test data are reported for a patient with an incorrectly positioned electrode array, prior to and following reimplantation, and compared to data obtained in 42 patients with normal insertions.
One patient with an incorrectly placed electrode array, prior to and following reimplantation, and a sample of 42 implant recipients with correct insertions.
The patient with the malpositioned electrode array was explanted and reimplanted. The results for the first and the second implant, with regards to objective test results, are compared. The results are also compared to the data obtained on 42 implant recipients with normal insertions.
The objective test data (primarily AEV data) are compared with AEV results obtained in 42 patients with normal electrode insertions.
Although the electrode array had folded up on itself during insertion, intraoperative electrode impedances and VIII nerve responses, as well as postoperative electrically evoked auditory brainstem responses, were within normal limits. However, averaged electrode voltages, obtained with the Nucleus Crystal Integrity Test system, were abnormal and consistent with a low-impedance pathway between the apical and middle portions of the electrode array.
人们认为，人工耳蜗电极阵列在耳蜗内的正确放置对于获得最佳言语感知效果至关重要。然而，人工耳蜗功能的客观测试通常很少或根本无法提供有关电极阵列在耳蜗内放置情况的信息。我们报告了一名患者在插入过程中电极阵列自身发生折叠的情况下，进行的包括平均电极电压（AEV）测量在内的各种客观测试结果。
确定是否有任何客观测量方法能提供电极放置不正确的证据。
报告了一名电极阵列位置不正确的患者在再次植入前后的客观测试数据，并与42名正常植入患者获得的数据进行比较。
一名电极阵列放置不正确的患者在再次植入前后，以及42名植入正确的受者样本。
将电极阵列位置不当的患者的植入物取出并重新植入。比较首次和第二次植入在客观测试结果方面的情况。还将结果与42名正常植入受者获得的数据进行比较。
将客观测试数据（主要是AEV数据）与42名电极插入正常的患者获得的AEV结果进行比较。
尽管电极阵列在插入过程中自身发生了折叠，但术中电极阻抗和第八神经反应以及术后电诱发听觉脑干反应均在正常范围内。然而，使用Nucleus Crystal Integrity Test系统获得的平均电极电压异常，且与电极阵列顶端和中部之间的低阻抗通路一致。
