Gärtner Lutz, Backus Bradford C, Le Goff Nicolas, Morgenstern Anika, Lenarz Thomas, Büchner Andreas
Department of Otolaryngology, Hannover Medical School, 30625 Hannover, Germany.
Oticon Medical, 06220 Vallauris, France.
J Clin Med. 2023 Sep 25;12(19):6194. doi: 10.3390/jcm12196194.
A percentage (i.e., 5.6%) of Cochlear Implant (CI) users reportedly experience unwanted facial nerve stimulation (FNS). For some, the effort to control this problem results in changing stimulation parameters, thereby reducing their hearing performance. For others, the only viable solution is to deactivate the CI completely. A growing body of evidence in the form of case reports suggests that undesired FNS can be effectively addressed through re-implantation with an Oticon Medical (OM) Neuro-Zti implant. However, the root of this benefit is still unknown: is it due to surgical adjustments, such as varied array geometries and/or positioning, or does it stem from differences in stimulation parameters and/or grounding? The OM device exhibits two distinct features: (1) unique stimulation parameters, including anodic leading pulses and loudness controlled by pulse duration-not current-resulting in lower overall current amplitudes; and (2) unconventional grounding, including both passive (capacitive) discharge, which creates a pseudo-monophasic pulse shape, and a 'distributed-all-polar' (DAP) grounding scheme, which is thought to reduce current spread. Unfortunately, case reports alone cannot distinguish between surgical factors and these implant-related ones. In this paper, we present a novel follow-up study of two CI subjects who previously experienced FNS before re-implantation with Neuro-Zti implants. We used the Oticon Medical Research Platform (OMRP) to stimulate a single electrode in each subject in two ways: (1) with traditional monopolar biphasic cathodic-first pulses, and (2) with distinct OM clinical stimulation. We progressively increased the stimulation intensity until FNS occurred or the sound became excessively loud. Non-auditory/FNS sensations were observed with the traditional stimulation but not with the OM clinical one. This provides the first direct evidence demonstrating that stimulation parameters and/or grounding-not surgical factors-play a key role in mitigating FNS.
据报道，一定比例（即5.6%）的人工耳蜗（CI）使用者会经历不必要的面神经刺激（FNS）。对于一些人来说，控制这个问题的努力导致刺激参数的改变，从而降低了他们的听力表现。对于另一些人来说，唯一可行的解决方案是完全停用人工耳蜗。越来越多的病例报告形式的证据表明，通过使用奥迪康医疗（OM）Neuro-Zti植入物进行重新植入，可以有效解决不期望的面神经刺激问题。然而，这种益处的根源仍然未知：是由于手术调整，如不同的阵列几何形状和/或定位，还是源于刺激参数和/或接地的差异？OM设备具有两个独特的特点：（1）独特的刺激参数，包括阳极领先脉冲和由脉冲持续时间而非电流控制的响度，从而导致总体电流幅度较低；（2）非常规接地，包括被动（电容性）放电，它产生伪单相脉冲形状，以及“分布式全极性”（DAP）接地方案，据认为该方案可减少电流扩散。不幸的是，仅靠病例报告无法区分手术因素和这些与植入物相关的因素。在本文中，我们对两名在重新植入Neuro-Zti植入物之前经历过面神经刺激的人工耳蜗受试者进行了一项新颖的随访研究。我们使用奥迪康医疗研究平台（OMRP）以两种方式刺激每个受试者中的单个电极：（1）使用传统的单极双相阴极优先脉冲，（2）使用独特的OM临床刺激。我们逐渐增加刺激强度，直到出现面神经刺激或声音变得过大。在传统刺激中观察到了非听觉/面神经刺激感觉，但在OM临床刺激中未观察到。这提供了第一个直接证据，证明刺激参数和/或接地而非手术因素在减轻面神经刺激方面起关键作用。
