Deshmukh Ashlesha, Settell Megan, Cheng Kevin, Knudsen Bruce, Trevathan James, LaLuzerne Maria, Blanz Stephan, Skubal Aaron, Verma Nishant, Romanauski Ben, Brucker-Hahn Meagan, Lam Danny, Lavrov Igor, Suminski Aaron, Weber Douglas, Fisher Lee, Lempka Scott, Shoffstall Andrew, Park Hyunjoo, Ross Erika, Zhang Mingming, Ludwig Kip
Wisconsin Institute for Translational Neuroengineering (WITNe), University of Wisconsin-Madison, Madison, WI, United States of America.
Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States of America.
J Neural Eng. 2025 Feb 20;22(1). doi: 10.1088/1741-2552/ad7f8b.
. Evoked compound action potentials (ECAPs) measured during epidural spinal cord stimulation (SCS) can help elucidate fundamental mechanisms for the treatment of pain and inform closed-loop control of SCS. Previous studies have used ECAPs to characterize neural responses to various neuromodulation therapies and have demonstrated that ECAPs are highly prone to multiple sources of artifact, including post-stimulus pulse capacitive artifact, electromyography (EMG) bleed-through, and motion artifact. However, a thorough characterization has yet to be performed for how these sources of artifact may contaminate recordings within the temporal window commonly used to determine activation of A-beta fibers in a large animal model.. We characterized sources of artifacts that can contaminate the recording of ECAPs in an epidural SCS swine model using the Abbott Octrode™ lead.. Spinal ECAP recordings can be contaminated by capacitive artifact, short latency EMG from nearby muscles of the back, and motion artifact. The capacitive artifact can appear nearly identical in duration and waveshape to evoked A-beta responses. EMG bleed-through can have phase shifts across the electrode array, similar to the phase shift anticipated by propagation of an evoked A-beta fiber response. The short latency EMG is often evident at currents similar to those needed to activate A-beta fibers associated with the treatment of pain. Changes in CSF between the cord and dura, and motion induced during breathing created a cyclic oscillation in all evoked components of recorded ECAPs.. Controls must be implemented to separate neural signal from sources of artifact in SCS ECAPs. We suggest experimental procedures and reporting requirements necessary to disambiguate underlying neural response from these confounds. These data are important to better understand the framework for epidural spinal recordings (ESRs), with components such as ECAPs, EMG, and artifacts, and have important implications for closed-loop control algorithms to account for transient motion such as postural changes and cough.
在硬膜外脊髓刺激（SCS）期间测量的诱发复合动作电位（ECAPs）有助于阐明疼痛治疗的基本机制，并为SCS的闭环控制提供信息。先前的研究已使用ECAPs来表征对各种神经调节疗法的神经反应，并证明ECAPs极易受到多种伪迹来源的影响，包括刺激后脉冲电容伪迹、肌电图（EMG）串扰和运动伪迹。然而，对于这些伪迹来源如何在通常用于确定大型动物模型中A-β纤维激活的时间窗口内污染记录，尚未进行全面的表征。我们使用雅培八电极™导联对硬膜外SCS猪模型中可能污染ECAPs记录的伪迹来源进行了表征。脊髓ECAP记录可能会受到电容伪迹、背部附近肌肉的短潜伏期EMG以及运动伪迹的污染。电容伪迹在持续时间和波形上可能与诱发的A-β反应几乎相同。EMG串扰可能会在整个电极阵列上产生相位偏移，类似于诱发的A-β纤维反应传播所预期的相位偏移。短潜伏期EMG通常在与激活与疼痛治疗相关的A-β纤维所需电流相似的电流下很明显。脊髓和硬脑膜之间脑脊液的变化以及呼吸过程中引起的运动在记录的ECAPs的所有诱发成分中产生了周期性振荡。必须实施控制措施以将神经信号与SCS ECAPs中的伪迹来源区分开来。我们建议了消除这些混淆因素以明确潜在神经反应所需的实验程序和报告要求。这些数据对于更好地理解硬膜外脊髓记录（ESRs）的框架很重要，ESRs包括ECAPs、EMG和伪迹等成分，并且对于闭环控制算法考虑诸如姿势变化和咳嗽等瞬态运动具有重要意义。
